Patent Publication Number: US-2013244126-A1

Title: High-temperature operating fuel cell module, and high-temperature operating fuel cell system

Description:
TECHNICAL FIELD 
     The present invention relates to a cooling structure of a solid oxide fuel cell (SOFC). 
     BACKGROUND ART 
     In recent years, development of high-efficient and clean energy sources has been demanded. As one of candidates of the high-efficient and clean energy sources, fuel cells have attracted attention. Among the fuel cells, a solid oxide fuel cell (SOFC) has a higher power generation efficiency than other kind of fuel cells such as a polymer electrolyte fuel cell or a phosphorous acid fuel cell, and therefore has attracted attention as a next-generation fuel cell. 
     The SOFC generates electric power and heat simultaneously through an electrochemical reaction (power generation reaction) between a fuel gas containing hydrogen and an oxidizing gas such as air containing oxygen. The SOFC generates a fuel gas (reformed gas) containing hydrogen as a major component, through a steam reforming method which performs a reforming reaction using a raw material gas and water. 
     The SOFC has a higher power generation efficiency as described above, but is higher in operating temperature (e.g., 750 degrees C. to 1000 degrees C.). To maintain power generation, it is necessary to cool the SOFC by a method adapted to the high-temperature SOFC. 
     To this end, conventionally, air guided to inside of a SOFC hot module as an oxidizing gas is used as a cooling medium for cooling the SOFC (e.g., Patent Literatures 2 and 3). Especially, the method disclosed in Patent Literature 2 includes the following steps and increases an oxygen utilization efficiency (Uo) by increasing a cooling efficiency. More specifically, the method disclosed in Patent Literature 2 includes the step of receiving in a temperature equilibration member, heat generated in conversion between a chemical energy and an electric energy, from a fuel cell, the step of performing pre-heating by diffusing the heat of the temperature equilibration member to an air flow via a heat exchange element, the step of directly diffusing the heat of the temperature equilibration member to the air flow to raise a temperature of the air up to a temperature near a reaction temperature, and the step of flowing the heated air flow to a cathode. 
     Also, there is disclosed a fuel cell which utilizes heat energy owned by air which has deprived heat from the SOFC by cooling the SOFC as an energy for pre-heating a fuel gas or an oxidizing gas (e.g., Patent Literatures 1 and 5). Also, there is proposed a solid oxide fuel cell module which lessens an influence on heat from a preheating section for preheating the fuel gas or the oxidizing gas, a reforming section which performs a reforming reaction to suppress a temperature distribution between cells, etc. (Patent Literature 4). 
     CITATION LIST 
     Patent Literature 
     
         
         Patent Literature 1: Japanese Laid-Open Patent Application Publication No. 2004-139960 
         Patent Literature 2: Japanese Patent Publication No. 3098813 
         Patent Literature 3: Japanese Laid-Open Patent Application Publication No. 2006-85982 
         Patent Literature 4: Japanese Laid-Open Patent Application Publication No. 2009-93923 
         Patent Literature 5: Japanese Laid-Open Patent Application Publication No. 2002-280023 
       
    
     SUMMARY OF THE INVENTION 
     Technical Problem 
     However, in the above stated prior arts, there is a problem that the oxygen utilization efficiency of the air supplied to the SOFC hot module cannot be improved efficiently. In particular, there is a problem that the oxygen utilization efficiency of the air cannot be improved to an extent that water can be supplied in a self-sustainable manner within the SOFC system. 
     Therefore, it is necessary to increase a value of the Uo to an extent that the water can be supplied in a self-sustainable manner by the air with an outside air temperature in the system. 
     However, the above stated prior arts disclosed in Patent Literatures 1 to 5 have problems that they do not have a configuration for improving the oxygen utilization efficiency of the air with a view to supplying the water easily in a self-sustainable manner especially within the SOFC system. 
     The present invention has been made in view of the above stated problems, and an object is to provide a high-temperature operating fuel cell module capable of improving the oxygen utilization efficiency of the air supplied. In particular, an object is to provide a high-temperature operating fuel cell module and a high-temperature operating fuel cell system which are capable of improving the utilization efficiency of the air to an extent that the water can be supplied easily in a self-sustainable manner within the system. 
     Solution to Problem 
     According to an aspect of the present invention, a high-temperature operating fuel cell module comprises: a high-temperature operating fuel cell including a power generation section for generating electric power through a power generation reaction by utilizing a fuel gas and air; and a reformer for generating a reformed gas as the fuel gas, by using a fluid supplied to the reformer, the reformed gas being generated from the fluid; wherein the fluid heated by heat owned by the high-temperature operating fuel cell is supplied to the reformer. 
     Advantageous Effects of the Invention 
     A high-temperature operating fuel cell module of the present invention has an advantage that a utilization efficiency of supplied air can be improved. In addition, the water can be supplied easily in a self-sustainable manner within a high-temperature operating fuel cell system including the high-temperature operating fuel cell module of the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a view schematically showing an example of a configuration for providing heat of SOFC to fluids (raw material and reforming water) supplied to a reformer for preheating the fluids in a SOFC hot module according an embodiment of the present invention. 
         FIG. 2  is a view schematically showing an example of paths through which air, a raw material and reforming water flow in the SOFC hot module according the embodiment of the present invention. 
         FIG. 3  is a view schematically showing a configuration of the SOFC hot module according the embodiment of the present invention. 
         FIG. 4  is a view schematically showing an example of paths through which air and fluids (raw material and reforming water) flow in the SOFC hot module according the embodiment. 
         FIG. 5  is a view schematically showing an example of paths through which air and fluids (raw material and reforming water) flow in the SOFC hot module according the embodiment of the present invention. 
         FIG. 6  is a view schematically showing an example of paths through which air and fluids (raw material and reforming water) flow in the SOFC hot module according the embodiment of the present invention. 
         FIG. 7  is a front view showing an example of a specific configuration of the SOFC hot module according the embodiment of the present invention. 
         FIG. 8  is a side view showing an example of the specific configuration of the SOFC hot module according the embodiment of the present invention. 
         FIG. 9  is a view showing an example of a flow of the air flowing through the SOFC hot module according the embodiment of the present invention. 
         FIG. 10  is a view showing an example of a flow of the raw material flowing through the SOFC hot module according the embodiment of the present invention. 
         FIG. 11  is a view showing an example of an obverse surface, a side surface and a reverse surface of an outer end header constituting the SOFC hot module according the embodiment of the present invention. 
         FIG. 12  is a view showing an example of an obverse surface, a side surface and a reverse surface of a cathode end interconnector constituting the SOFC hot module according the embodiment of the present invention. 
         FIG. 13  is a view showing an example of an obverse surface, a side surface and a reverse surface of SOFC constituting the SOFC hot module according the embodiment of the present invention. 
         FIG. 14  is a view showing an example of an obverse surface, a side surface and a reverse surface of an interconnector constituting the SOFC hot module according the embodiment of the present invention. 
         FIG. 15  is a view showing an example of an obverse surface, a side surface and a reverse surface of an anode end interconnector constituting the SOFC hot module according the embodiment of the present invention. 
         FIG. 16  is a view showing an example of an obverse surface, a side surface and a reverse surface of a reformer connection header constituting the SOFC hot module according the embodiment of the present invention. 
         FIG. 17  is a view showing an example of an obverse surface, a side surface and a reverse surface of a reformer constituting the SOFC hot module according the embodiment of the present invention. 
         FIG. 18  is a view schematically showing an example of a configuration of a SOFC system according the embodiment of the present invention. 
         FIG. 19  is a view showing an example of supply and generation of substances in a reforming efficiency and a fuel/oxygen utilization efficiency, in a cell reaction in which water of 1 mol is generated from hydrogen of 1 mol and oxygen of 0.5 mol. 
         FIG. 20  is a view showing an example of supply and generation of substances in the reforming efficiency and the fuel/oxygen utilization efficiency, in the cell reaction in which water of 1 mol is generated from hydrogen of 1 mol and oxygen of 0.5 mol. 
         FIG. 21  is a view showing an example of supply and generation of substances in the reforming efficiency and the fuel/oxygen utilization efficiency, in the cell reaction in which water of 1 mol is generated from hydrogen of 1 mol and oxygen of 0.5 mol. 
         FIG. 22  is a block diagram schematically showing an example of a configuration of a SOFC hot module having a configuration which is a premise of the present invention. 
         FIG. 23  is an example of an outer shape of the SOFC hot module of  FIG. 22 . 
         FIG. 24  is a view showing an example of a cross-sectional shape of the outer shape of the SOFC hot module, which is taken along A-A of  FIG. 23 . 
         FIG. 25  is a cross-sectional view showing an example of a structure of a flatten tubular segmented-in-series type SOFC included in the SOFC hot module of FIG.  22 . 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     (Finding which is a Basis of the Present Invention) 
     As finding which is a basis of the present invention, a relation between an oxygen utilization efficiency of air (oxidizing gas) supplied to a SOFC hot module and supplying of water within a SOFC system in a self-sustainable manner will be described with reference to  FIGS. 19 and 20 .  FIGS. 19 and 20  are views each showing an example of supply and generation of substances in a reforming efficiency and a fuel/oxygen utilization efficiency, in a cell reaction in which water of 1 mol is generated from hydrogen of 1 mol and oxygen of 0.5 mol. 
     Supplying of water within the SOFC system in a self-sustainable manner is closely related to the air utilization efficiency and a cooling method of a fuel cell. A table of  FIG. 19  shows supply and generation of substances corresponding to hydrogen consumption of 1 mol, when the reforming efficiency is 80%, the fuel utilization efficiency (Uf) is 80%, S/C=2.5, and the oxygen utilization efficiency (Uo) is 0.2. A table of  FIG. 20  shows supply and generation of substances corresponding to hydrogen consumption of 1 mol, when the reforming efficiency is 80%, the fuel utilization efficiency (Uf) is 80%, S/C=2.5, and the oxygen utilization efficiency (Uo) is 0.3. The fuel utilization efficiency is a value satisfying a relation indicating the following formula (1), while the oxygen utilization efficiency is a value satisfying a relation indicating the following formula (2). 
       Fuel utilization efficiency(Uf)=(Consumed hydrogen)/(Supplied hydrogen)  (1)
 
       Oxygen utilization efficiency(Uo)=(Consumed oxygen)/(Supplied oxygen)  (2)
 
     As can be seen from the tables of  FIGS. 19 and 20 , when the raw material is methane (CH 4 ) and S/C is 2.5, the reforming water of 0.98 mol corresponding to consumed hydrogen of 1 mol is necessary. If this reforming water can be recovered from water generated in the cell and water generated in combustion, and used as the reforming water again, it can be said that the water can be supplied in a self-sustainable manner within this system. 
     These generated water results from combustion of hydrogen contained in fuel. An absolute amount of the generated water depends on a fuel amount. Whether or not the generated water can be recovered efficiently depends greatly on the oxygen utilization efficiency (Uo). 
     For example, as shown in the table of  FIG. 20 , in a case where Uo is 0.3, a steam amount in a combustion gas discharged from the SOFC hot module is 1.48 mol and a dew point is 55 degrees C. If the combustion gas is cooled to 35 degrees C. which is an outside air temperature, condensed water of 1.02 mol can be recovered, and the recovered condensed water can cover the reforming water of 0.98 mol which is required for the reforming reaction. 
     By comparison, in a case where Uo is 0.2 in the table of  FIG. 19 , the combustion gas is diluted by the air. The steam amount in the combustion gas remains 1.48 mol, but the dew point decreases to 48 degrees C. unlike the case where Uo is 0.3. For this reason, even if the combustion gas is cooled to 35 degrees C. which is the outside air temperature, only the condensed water of 0.78 mol can be recovered, and the recovered condensed water cannot cover the reforming water of 0.98 mol which is required for the reforming reaction. 
     To air-cool the SOFC, the air of an amount which is five times (Uo=0.2 in terms of the oxygen utilization efficiency) as much as an amount of air required in normal power generation of the SOFC in view of a heat capacity of the air, etc. However, in the case where Uo is 0.2, in a condensation method which cools the combustion gas by the air of the outside air temperature of 35 degrees C., the condensed water of the amount required for the reforming reaction cannot be generated as described above. That is, the water cannot be supplied in a sustainable manner. The above stated findings apply to high-temperature operating fuel cells other than the SOFC. Based on the above stated findings, the present invention provides aspects described below. 
     According to a first aspect the present invention, a high-temperature operating fuel cell module comprises: a high-temperature operating fuel cell including a power generation section for generating electric power through a power generation reaction by utilizing a fuel gas and air; and a reformer for generating a reformed gas as the fuel gas, by using a fluid supplied to the reformer, the reformed gas being generated from the fluid; wherein the fluid heated by heat owned by the high-temperature operating fuel cell is supplied to the reformer. 
     The high-temperature operating fuel cell module is defined as a fuel cell operating at a temperature which is equal to or higher than about 400 degrees C. As the high-temperature operating fuel cell module, there are, for example, SOFC (solid oxide fuel cell) or MCFC (molten carbonate fuel cell). The fluid from which the reformed gas is generated refers to, for example, water and a raw material in the case of steam reforming, oxygen and a raw material in the case partial combustion method (partial oxidation method), and oxygen, water, and a raw material in the case of auto thermal reforming. 
     In the above configuration, the fluid supplied to the reformer deprives the heat owned by the high-temperature operating fuel cell, is heated and is supplied to the reformer. That is, the heat obtained from the high-temperature operating fuel cell can be converted into a vaporization energy required to generate, for example, a humidified raw material. 
     Therefore, the high-temperature operating fuel cell can be cooled efficiently by the supplied fluid, which can reduce an amount of the air for cooling the high-temperature operating fuel cell. Therefore, a utilization efficiency of the air can be increased. That is, the high-temperature operating fuel cell module of the present invention has an advantage that the utilization efficiency of the supplied air can be increased. 
     According to a second aspect of the present invention, the high-temperature operating fuel cell module according to the first aspect may comprise a first heat exchanger section which exchanges heat between the high-temperature operating fuel cell and the air such that the air cools the high-temperature operating fuel cell and is heated by the heat of the high-temperature operating fuel cell before the air is utilized in the power generation reaction; and a second heat exchanger section for exchanging heat between the fluid and the air heated by the heat exchange in the first heat exchanger section such that the air heats the fluid supplied to the reformer; wherein the fluid heated by the heat exchange in the second heat exchanger section is supplied to the reformer, while the air from which the heat has been deprived by the heat exchange in the second heat exchanger section, is supplied to the power generation section of the high-temperature operating fuel cell. 
     In the above configuration, the first heat exchanger section is able to deprive the heat from the high-temperature operating fuel cell by the supplied air to cool the fuel cell and heat the air. In addition, the second heat exchanger section is able to deprive the heat from the heated air to heat the fluid supplied to the reformer and cool the air. The cooled air can be supplied to the power generation section in the high-temperature operating fuel cell. 
     Therefore, the high-temperature operating fuel cell can be cooled efficiently plural times by the supplied air, and hence the utilization efficiency of the air can be increased. That is, the high-temperature operating fuel cell module has an advantage that the utilization efficiency of the supplied air can be increased. 
     Since the utilization efficiency of the supplied air can be increased, a supply amount of the air can be reduced as compared to a configuration in which the air is supplied excessively as an oxidizing agent used in the power generation reaction and cools the SOFC like the conventional configuration. Because of this, a dew point at which the condensed water of a required amount is obtained as the reforming water from the exhaust gas can be made higher than in the conventional configuration. As a result, the water can be supplied in a self-sustainable manner within a high-temperature operating fuel cell system including the high-temperature operating fuel cell module of the present invention. 
     According to a third aspect of the present invention, in the high-temperature operating fuel cell module according to the second aspect, the reformed gas generated by the reformer may be utilized as the fuel gas in the power generation section of the high-temperature operating fuel cell and as a cooling medium for cooling the high-temperature operating fuel cell. 
     In the above configuration, since the reformed gas utilized as the fuel gas can be utilized as the cooling medium of the high-temperature operating fuel cell, the high-temperature operating fuel cell can be cooled efficiently. Thus, since the supply amount of the air can be reduced, a dew point at which the condensed water of a required amount is obtained as the reforming water from the exhaust gas can be made higher than in the conventional configuration. As a result, the water can be supplied in a self-sustainable manner within a high-temperature operating fuel cell system including the high-temperature operating fuel cell module of the present invention. 
     According to a fourth aspect of the present invention, the high-temperature operating fuel cell module according to a second or third aspect, may further comprise a third heat exchanger section for exchanging heat between the air, from which the heat has been deprived by the heat exchange in the second heat exchanger section, and the high-temperature operating fuel cell such that the high-temperature operating fuel cell is cooled by the air; and a fourth heat exchanger section for exchanging heat between the air heated by the heat exchange in the third heat exchanger section and the fluid; wherein the fluid heated by the heat exchange in the second heat exchanger section and in the fourth heat exchanger section is supplied to the reformer, and the air, from which the heat has been deprived by the heat exchange in the fourth heat exchanger section is supplied to the power generation section of the high-temperature operating fuel cell to be utilized as an oxidizing agent and as a cooling medium for cooling the high-temperature operating fuel cell. 
     According to a fifth aspect of the present invention, the high-temperature operating fuel cell module according to the fourth aspect, may further comprise a fifth heat exchanger section for exchanging heat between the fluid heated by the heat exchange in the second heat exchanger section and in the fourth heat exchanger section, and the high-temperature operating fuel cell such that the fluid is heated and the high-temperature operating fuel cell is cooled, before the fluid heated by the heat exchange in the second heat exchanger section and in the fourth heat exchanger section is supplied to the reformer. 
     In the above configuration, the fifth heat exchanger section is able to exchange heat between the fluid and the high-temperature operating fuel cell. Although the fluid which exchanges heat with the high-temperature operating fuel cell has already been heated by the heat exchange with the air in the second heat exchanger section and in the fourth heat exchanger section, the temperature of the fluid is sufficiently low as compared to a heat generation temperature in the high-temperature operating fuel cell. Therefore, by the heat exchange in the fifth heat exchanger section, the fluid can deprive heat from the high-temperature operating fuel cell to cool the high-temperature operating fuel cell, while the fluid is further heated by the heat deprived from the high-temperature operating fuel cell, and the heated fluid is supplied to the reformer. 
     The fact that the heat generated in the high-temperature operating fuel cell is supplied to the fluid is equivalent to the fact the heat is supplied to the reformer supplied with the fluid. That is, by supplying the heat generated in the high-temperature operating fuel cell to the fluid, the heat generated in the high-temperature operating fuel cell can be converted into a reforming energy. 
     Since the high-temperature operating fuel cell module according to the fifth aspect is able to cool the high-temperature operating fuel cell by converting the heat owned by the high-temperature operating fuel cell into a reforming energy, the supply amount of the air can be reduced, and as a result, the utilization efficiency of the air can be increased. 
     According to a sixth aspect of the present invention, the high-temperature operating fuel cell module according to the fifth aspect, may further comprise a stacked flat plate type cell stack including a plurality of high-temperature operating fuel cells and a plurality interconnectors which are stacked together such that the plurality of high-temperature operating fuel cells and the plurality interconnectors are arranged alternately; a raw material supply layer placed at one end portion of the stacked flat plate type cell stack to supply the fluid to the stacked flat plate type cell stack; and a reformer connection layer placed at the other end portion of the stacked flat plate type cell stack and between the stacked flat plate type cell stack and the reformer to connect the stacked flat plate type cell stack and the reformer to each other; wherein the raw material supply layer may include the second heat exchanger section and the fourth heat exchanger section and generates a humidified raw material by the heat exchange between the air and the fluid in the second heat exchanger section and in the fourth heat exchanger section; and wherein the reformer connection layer may supply the air to the stacked flat plate type cell stack and supplies the humidified raw material generated in the raw material supply layer to the reformer. 
     According to a seventh aspect of the present invention, in the high-temperature operating fuel cell module according to the sixth aspect, the stacked flat plate type cell stack may have on an outer peripheral portion a first air passage through which the air flows, as the first heat exchanger section which exchanges heat between the supplied air and the high-temperature operating fuel cell. 
     According to an eighth aspect of the present invention, in the high-temperature operating fuel cell module according to the sixth or seventh aspect, the stacked flat plate type cell stack may have on an outer peripheral portion a second air passage through which the air flows, as a third heat exchanger section for exchanging heat between the air, from which the heat has been deprived by the heat exchange in the second heat exchanger section, and the high-temperature operating fuel cell. 
     According to a ninth aspect of the present invention, in the high-temperature operating fuel cell module according to one of the sixth to eighth aspects, the stacked flat plate type cell stack may have on an outer peripheral portion a raw material passage through which the fluid flows, as a fifth heat exchanger section for exchanging heat between the fluid heated by the heat exchange in the second heat exchanger section and in the fourth heat exchanger section, and the high-temperature operating fuel cell. 
     According to a tenth aspect of the present invention, in the high-temperature operating fuel cell module according to one of the sixth to ninth aspects, the stacked flat plate type cell stack may include an exhaust pipe which guides a combustion exhaust gas resulting from a power generation reaction in the power generation section to the reformer; and the reformer may utilize combustion heat generated by combustion of the combustion exhaust gas guided through the exhaust pipe, in a reforming reaction. 
     In the above configuration, the high-temperature operating fuel cell module is configured such that the reformer performs a reforming reaction by utilizing the combustion heat generated by combusting the combustion exhaust gas exhausted as a result of the power generation reaction in the power generation section of the high-temperature operating fuel cell. 
     The combustion exhaust gas exhausted as a result of the power generation reaction includes unused fuel and air (oxidizing agent) in the high-temperature operating fuel cell, and is a gas having the heat generated in the power generation reaction. 
     In the above configuration, the reformer performs the reforming reaction by utilizing the combustion heat generated by combusting the combustion exhaust gas. A portion of the combustion heat can be covered by the heat of the combustion exhaust gas which is generated in the power generation reaction. Therefore, the heat generated in the power generation reaction of the high-temperature operating fuel cell can be supplied to the reformer via the combustion exhaust gas. 
     As described above, since the heat generated in the high-temperature operating fuel cell can be utilized in the reforming reaction in the reformer, the utilization efficiency of the air can be increased. 
     According to an eleventh aspect of the present invention, in the high-temperature operating fuel cell module according to one of the sixth to tenth aspects, the high-temperature operating fuel cell may be a metal support high-temperature operating fuel cell in which an anode, an electrolyte, and a cathode are provided on a metal base plate as a support member; and therein the metal base plate of the high-temperature operating fuel cell may be provided with through-holes defining portions of the first air passage, the second air passage and the raw material passage, respectively, in the stacked flat plate type cell stack. 
     In accordance with the above configuration, since the high-temperature operating fuel cell uses the metal base plate as the support member, a heat conductivity can be improved as compared to a case where the base plate is made of ceramic like the conventional SOFC. This makes it possible to efficiently perform exchange between the heat of the air flowing through the first air passage and the second air passage and the heat of the raw material (humidified raw material) flowing through the raw material passage in the stacked flat plate type cell stack, and the heat generated in the high-temperature operating fuel cell. 
     The metal base plate is provided with the through-holes defining portions of the first air passage, the second air passage and the raw material passage, respectively. This metal base plate is easily finely processed, etc., as compared to the base plate made of ceramic. Therefore, the openings of the through-holes can have a complicated shape such as a comb shape having a plurality of projections. For example, when the openings have the comb shape, contact areas between the air flowing through the first air passage and the second air passage and the raw material flowing through the raw material passage, and the stacked flat plate type cell stack, can be increased. As a result, efficiency of the heat exchange can be further improved. 
     According to a twelfth aspect of the present invention, in the high-temperature operating fuel cell module according to the tenth or eleventh aspect, the reformer connection layer may includes: a humidified raw material supply hole as a through-hole through which a humidified raw material generated in the raw material supply layer is guided to the reformer; a reformed gas supply hole as a through-hole through which the reformed gas generated in the reformer is supplied to the power generation section in the stacked flat plate type cell stack; and a combustion exhaust gas supply hole as a through-hole through which the combustion exhaust gas guided from the power generation section in the stacked flat plate type cell stack through the exhaust pipe is supplied to the reformer; the reformer may include: a humidified raw material receiving hole as a through-hole which receives the humidified raw material supplied via the humidified raw material supply hole; a reformed gas exhaust hole as a through-hole through which the generated reformed gas is exhausted to the reformer connection layer; and a combustion section for combusting the combustion exhaust gas supplied via the combustion exhaust gas supply hole to obtain heat required for the reforming reaction. 
     In accordance with the above configuration, in a state in which the reformer connection layer and the reformer are stacked together and integrated, the gases (humidified raw material, reformed gas, and combustion exhaust gas) can be given and received, and heat can be given and received via joint surfaces of the reformer connection layer and the reformer. 
     According to a thirteenth aspect of the present invention, a high-temperature operating fuel cell module comprises a high-temperature operating fuel cell including a power generation section for generating electric power through a power generation reaction by utilizing a fuel gas and air; and a reformer for generating a reformed gas, by using a fluid supplied to the reformer, the reformed gas being generated from the fluid; wherein the high-temperature operating fuel cell module being configured in such a manner that the air is flowed through the high-temperature operating fuel cell such that the air cools the high-temperature operating fuel cell and is heated by heat of the high-temperature operating fuel cell before the air is utilized in the power generation section, the fluid supplied to the reformer is heated by heat exchange between the air heated while the air is flowed through the high-temperature operating fuel cell and the fluid, and then the air heated by the heat exchange is flowed to the high-temperature operating fuel cell such that a flow of the air is turned back to be utilized to cool the high-temperature operating fuel cell. 
     According to a fourteenth aspect of the present invention, a high-temperature operating fuel cell system comprises the high-temperature operating fuel cell modules according to the first or thirteenth aspect; and a condensation heat exchanger section for exchanging heat between the exhaust gas exhausted from the high-temperature operating fuel cell module and outside air to condense a moisture contained in the exhaust gas to generate condensed water; wherein the condensed water generated by the condensation heat exchanger section is supplied as reforming water to the high-temperature operating fuel cell module. 
     In accordance with the above configuration, the high-temperature operating fuel cell module is configured such that the fluid supplied to the reformer deprives the heat owned by the high-temperature operating fuel cell, is heated, and is supplied to the reformer. That is, the heat obtained from the high-temperature operating fuel cell can be converted into, for example, a vaporization energy required to generate the humidified raw material. 
     Therefore, the high-temperature operating fuel cell can be cooled efficiently by the supplied fluid, and hence the utilization efficiency of the air can be improved. That is, the high-temperature operating fuel cell module of the present invention has an advantage that the utilization efficiency of the supplied air can be increased. 
     Since the high-temperature operating fuel cell system includes the condensation heat exchanger in addition to the above stated high-temperature operating fuel cell module, the exhaust gas exhausted from the high-temperature operating fuel cell module can be cooled by the heat exchange with the outside air to obtain the moisture contained in the exhaust gas. The obtained moisture can cover the reforming water required in the power generation reaction in the solid oxide fuel cell. 
     That is, the high-temperature operating fuel cell system has an advantage that the utilization efficiency of the supplied air can be increased. 
     Since the utilization efficiency of the supplied air can be improved, an air supply amount can be reduced as compared to a configuration in which the air is supplied excessively as an oxidizing agent used in the power generation reaction and cools the SOFC like the conventional configuration. Because of this, a dew point at which the condensed water of a required amount is obtained as the reforming water from the exhaust gas can be made higher than in the conventional configuration. Thus, the moisture contained in the exhaust gas can be condensed by the air of the outside air temperature without preparing cooling water or the like. 
     Therefore, the high-temperature operating fuel cell system of the present invention has an advantage that the water can be supplied easily in a self-sustainable manner within the system. 
     Next, a configuration of the high-temperature operating fuel cell module in the fuel cell system according to the embodiment of the present invention will be described. In the present embodiment, as an example of the high-temperature operating fuel cell, a solid oxide fuel cell (SOFC) will be described. However, the high-temperature operating fuel cell is not limited to the SOFC, so long as its operation temperature is equal to or higher than 400 degrees C. For example, the high-temperature operating fuel cell may be a molten carbonate fuel cell (MCFC). 
     Prior to describing a configuration of a SOFC hot module  100  according to the embodiment of the present invention, a configuration (configuration according to comparative example) of a SOFC hot module  1000  which is a premise of the present invention will be described with reference to  FIG. 22 . 
     (Example of a Configuration as a Premise of the Present Invention) 
       FIG. 22  is a block diagram schematically showing an example of a configuration of the SOFC hot module  1000  according to comparative example of the present invention. 
     As shown in  FIG. 22 , the SOFC hot module  1000  includes a SOFC stack (high-temperature operating fuel cell stack, stacked flat plate type cell stack)  50  including stacked SOFCs (high-temperature operating fuel cells)  20  each having a cathode  21  and an anode  22  (power generation section). In the present invention, a section which includes the cathode  21  and the anode  22 , and generates electric power by using fuel and air through a power generation reaction will be referred to as the power generation section. In addition, the SOFC hot module  1000  includes a reformer  40  which steam-reforms a raw material such as a city gas and a vaporizer  41  which vaporizes reforming water used in the steam reforming and supplies the vaporized reforming water to the reformer  40 . 
     A combustion section  30  is provided between the SOFC  20 , and the reformer  40  and the vaporizer  41  to cover reforming reaction heat required in the reformer  40  and vaporization heat required in the vaporizer  41 . The combustion section  30  combusts exhaust air (cathode-off-gas) exhausted from the cathode  21  and exhaust hydrogen (anode-off-gas) exhausted from the anode  22 , to generate a water vaporization energy in the vaporizer  41  and a reforming reaction energy in the reformer  40 . At start-up of the SOFC, the combustion section  30  combusts unreformed raw material to preliminarily heat an interior of the SOFC hot module  1000 . That is, a burner  31  (not shown in  FIG. 22 ) combusts the cathode-off-gas exhausted from the cathode  21  in the SOFC  20  and the anode off-gas exhausted from the anode  22  in the SOFC  20  to generate combustion heat used for activating the reformer  40  and the vaporizer  41 . 
     A temperature of the heat required for the reforming reaction is about 650 degrees C., while an added water amount required for the reforming reaction is such that S/C (steam carbon ratio; mol ratio between water and carbon in the raw material) is 2.0 or greater at smallest and is about 2.5 to 3.0. Under a state in which these conditions are controlled to be maintained, a hydrogen-rich reformed gas is generated from the raw material and the reforming water. 
     The reformed gas generated in the reformer  40  is supplied to the anode  22  of the power generation section in the SOFC  20 . The air is supplied from a blower (not shown) to the cathode  21 . A reaction occurs electrochemically as indicated by the following formula (3). 
       H 2 +½O 2 →H 2 O  (3)
 
     This reaction is similar to the combustion reaction of hydrogen. A basic principle of the fuel cell is such that an energy corresponding to this combustion energy is taken out electrochemically. In the power generation through this reaction, heat is generated simultaneously. Waste heat resulting from the power generation is removed by excess air (Uo=about 0.2) supplied to the cathode  21  in a conventional configuration. Exhaust gas heat containing the removed heat is secondarily used as energy for vaporization, reforming, preheating of air, etc. 
     As a result, the vaporizer  41  and the reformer  40  are activated by the waste heat generated during the power generation in the SOFC and the combustion heat of surplus reformed gas. The fuel gas (reformed gas) generated in the activated vaporizer  41  and the activated reformer  40  activate the SOFC, which is a kind of a power regenerative mechanism. A collective entity which implements the power regenerative mechanism will be referred to as the SOFC hot module  1000 . The exhaust gas exhausted from the SOFC hot module  1000  contains the water generated in the fuel cell and the water generated in the combustion, in the form of the steam. 
     Although not shown, the SOFC  20  is further provided with a current collecting member via which the electric power is drawn to outside. In this way, the user can utilize this electric power. 
     The above stated electrochemical reaction is carried out in the SOFC  20  in an oxidizing atmosphere of a high temperature of about 1000 degrees C. To make this electrochemical reaction active, it becomes necessary to heat (pre-heat) the air, or the like as the reaction gas up to a desired temperature (about several hundreds degrees C.). 
     To this end, the SOFC hot module  1000  includes an air preheating section  10  for heating the air supplied from the blower (not shown) by the exhaust gas heat within the SOFC hot module  1000 , before it is supplied to the cathode  21  in the SOFC  20 . 
     Next, a specific structure of the SOFC hot module  1000  according to comparative example will be described. 
     The SOFC hot module  1000  has an outer shape as shown in  FIG. 23 .  FIG. 23  is an example of the outer shape of the SOFC hot module  1000  of  FIG. 22 . The SOFC hot module  1000  includes inside thereof the air preheating section  10 , the SOFC stack  50 , the combustion section  30 , the reformer  40  and the vaporizer  41  as described above. These members are covered with an outer member having a substantially parallelepiped shape. This outer member has a heating insulating material to prevent heat from being released from inside of the outer member to outside. 
     In the example of the outer shape of  FIG. 23 , the SOFC hot module  1000  is provided on a right side surface thereof with an air inlet  62  to receive the air supplied from the blower (not shown). In addition, the SOFC hot module  1000  is provided on a right portion of an upper surface thereof with a raw material inlet  61  to receive the reforming water and the raw material. Further, the SOFC hot module  1000  is provided with an exhaust port  63  on a portion of the left side surface which is in the vicinity of the upper surface to exhaust the exhaust gas. For example,  FIG. 24  shows a cross-sectional shape of the SOFC hot module  1000 , which is taken along A-A of  FIG. 23 .  FIG. 24  is a view showing an example of the cross-sectional shape of the outer shape of the SOFC hot module  1000 , which is taken along A-A of  FIG. 23 . 
     As shown in  FIG. 24 , in the SOFC hot module  1000 , the vaporizer  41  and the reformer  40  are aligned on a center line of its cross-section. Assuming that the vaporizer  41  and the reformer  40  are one straight line, the combustion sections  30 , the SOFCs  20 , and the air preheating sections  10  are arranged laterally symmetrically, with respect to this straight line. 
     The SOFC  20  is provided with supply headers  13  which receive the fuel gas (reformed gas) and the air supplied, on a bottom surface side of the SOFC hot module  1000  and provided with discharge headers  14  which discharge the cathode-off-gas and the anode-off-gas, on an upper surface side of the SOFC hot module  1000 . 
     Specifically, the raw material and the reforming water are supplied to the vaporizer  41  through the raw material inlet  61 . The vaporizer  41  vaporizes the reforming water. A mixture gas of the steam and the raw material is generated and supplied to the reformer  40 . The reformer  40  generates hydrogen through the steam reforming reaction, and supplies as the fuel gas (reformed gas) to the supply headers  13  in the SOFC  20  through reformed gas inlets  45 . 
     By comparison, the air is supplied to the air preheating sections  10  through the air inlets  62 . The air pre-heated in the air preheating sections  10  is discharged toward the SOFC  20  through air outlets  9  and supplied to the SOFC  20  via the supply headers  13 . 
     As shown in  FIG. 24 , the combustion sections  30  are provided on both side surfaces of the reformer  40 . In the combustion sections  30 , the burners  31  combust the anode-off-gas, the cathode-off-gas, or the like. 
     As shown in  FIG. 25 , for example, the shape of the SOFC  20  may be realized as so-called a flatten tubular segmented-in-series type SOFC.  FIG. 25  is a cross-sectional view showing an example of a structure of the flatten tubular segmented-in-series type SOFC, in the SOFC hot module  1000  of  FIG. 22 . 
     In a case where the SOFC  20  is realized as the flatten tubular segmented-in-series type SOFC as shown in  FIG. 25 , there is provided a cell in which the anode  22 , an electrolyte  23 , and the cathode  21  are stacked together in this order, on outside of a base tubular body  25  which is a porous support pipe, and cells are arranged such that an interconnector  24  intervenes between them. In the case of the flatten tubular segmented-in-series type SOFC, the fuel gas (reformed gas) flows inside of the base tubular body  25 , while the air flows outside of the base tubular body  25 . 
     (SOFC Hot Module) 
     Next, a characteristic configuration of the SOFC hot module  100  according to the present embodiment will be described with reference to  FIG. 1 .  FIG. 1  is a view schematically showing an example of a configuration which provides heat of the SOFC  20  to fluids (raw material and water) supplied to the reformer  40  in the SOFC hot module  100  according the embodiment of the present invention. For easier explanation,  FIG. 1  shows only flows of the fluids (raw material and water) supplied to the reformer  40 , and does not show the flow of the air supplied to the SOFC  20  constituting the SOFC stack  50 . 
     As shown in  FIG. 1 , the SOFC hot module  100  according to the present embodiment is configured in such a manner that the reformer  40  generates the reformed gas using the fluids supplied from outside, such as the raw material and the water (reforming water) and supplies the reformed gas as the fuel gas to the SOFC stack  50 . As shown in  FIG. 1 , the fluids (raw material and water) are preheated by the heat generated in the SOFC  20  (SOFC stack  50 ) before they are supplied to the reformer  40 . 
     In the SOFC hot module  100  of the present embodiment, the fluids supplied from outside deprive the heat from the SOFC  20  (SOFC stack  50 ), to cool the SOFC  20 , so that the fluid is heated. Therefore, the raw material can be pre-heated or the reforming water can be vaporized by utilizing the heat from the SOFC  20  (SOFC stack  50 ). That is, the heat obtained from the SOFC  20  can be converted into a vaporization energy required to generate, for example, a humidified raw material. 
     Therefore, the amount of the air supplied to the SOFC  20  to cool the SOFC  20  (SOFC stack  50 ) can be reduced. 
     Next, a specific configuration for implementing the SOFC hot module  100  of  FIG. 1  will be described with reference to  FIGS. 2 and 3 .  FIG. 2  is a view schematically showing an example of paths through which the air, the raw material, and the reforming water flow in the SOFC hot module  100  according the present embodiment.  FIG. 3  is a view schematically showing a configuration of the SOFC hot module  100  according the present embodiment. 
     The SOFC hot module  100  according the present embodiment is different from the above stated SOFC hot module  1000  according to comparative example in the features described below. In the SOFC hot module  100  according the present embodiment, the same components as those of the SOFC hot module  1000  according to comparative example are identified by the same reference symbols and will not be described. 
     In the SOFC hot module  1000  according to comparative example, as described above, the air supplied to the SOFC hot module  1000  is heated by the heat of the exhaust gas or the like in the air pre-heating section  10  and supplied to the cathode  21  of the SOFC  20 . By comparison, in the SOFC hot module  100  according the present embodiment, the air is supplied to the cathode  21  through the path described below. 
     Specifically, the air supplied to the SOFC hot module  100  is caused to exchange heat with the SOFC  20  in a first heat exchanger section  11  in the SOFC stack  50 . By this heat exchange, the air is heated (pre-heated) by the heat owned by the SOFC  20 . In other words, the air cools the SOFC  20  (pre-cooling) and raises its temperature. Then, the air which has gained heat by this heating is output to a second heat exchanger section  12 . At least one of the raw material and the reforming water has been supplied to the second heat exchanger section  12 . The second heat exchanger section  12  exchanges heat between the air having gained heat, and at least one of the raw material and the reforming water. 
     The air having gained the heat from the SOFC  20  discards the heat by the heat exchange in the second heat exchanger section  12  and is allowed to have a state in which it will be able to cool substances. In this state, the air is supplied to the SOFC  20 . The air is consumed as the oxidizing gas in a cell reaction and cools (main cooling) the SOFC  20  again. That is, the air having decreased its heat amount by the heat exchange with at least one of the raw material and the reforming water, exchanges heat with the SOFC  20  while going through the electrochemical reaction in the power generation section in the SOFC  20 . 
     At least one of the raw material and the reforming water which have been heated by the heat exchange with the air is supplied to the reformer  40 . The reformer  40  performs the steam reforming. The reformed gas (fuel gas) generated through the steam reforming is supplied to the anode  22  in the power generation section in the SOFC  20 . The reformed gas cools the SOFC  20  when the reformed gas is consumed as the fuel gas in the cell reaction. 
     As described above, in the SOFC hot module  100  according the present embodiment, the air supplied from outside cools the SOFC  20 . The air heated by the heat owned by the SOFC  20  is caused to exchange heat with at least one of the raw material and the reforming water, and thereby is cooled. The air, from which a portion of its heat has been deprived, by this heat exchange, is supplied as an oxidant to the cathode  21  in the power generation section, and cools the SOFC  20  as a cooling medium (main cooling) again. The reformed gas generated in the reformer  40  is supplied as the fuel gas to the anode  22  in the power generation section, and cools the SOFC  20  as the cooling medium. 
     In the SOFC hot module  100  according the present embodiment, combustion exhaust gases (cathode-off-gas and anode-off-gas) exhausted after the electrochemical reaction in the SOFC  20  is heated by the heat generated in the power generation reaction in the power generation section in the SOFC  20  and is guided to the combustion section  30  in this heated state. The combustion section  30  combusts these combustion exhaust gases. By the resulting combustion heat, the reforming reaction in the reformer  40  proceeds. The combustion exhaust gases exhausted from the SOFC  20  contain unconsumed fuel gas and the air (oxygen). The combustion section  30  combusts the unconsumed fuel gas and the air. 
     From a view point of energy, a portion of the waste heat resulting from the power generation in the SOFC  20  is used as a vaporization energy and a reforming energy, which can reduce the amount of air used for cooling the cell. 
     As can be seen from the comparison between the configuration of the SOFC hot module  1000  according to comparative example of  FIG. 19  and the configuration of the SOFC hot module  100  according the present embodiment, a location of the vaporizer  41  is different. As can be seen from the comparison between them with reference to  FIGS. 3 and 19 , the vaporizer  41  is placed in a previous stage of the reformer  40 , and arrangement of them is the same systematically. However, in the configuration of the comparative example of  FIG. 19 , the reformer  40  and the vaporizer  41  are arranged adjacently. By comparison, in the SOFC hot module  100  according the present embodiment, as shown in  FIG. 3 , the reformer  40  and the vaporizer  41  are placed to be distant from each other. More specifically, in the SOFC hot module  100  according the present embodiment, as shown in  FIG. 3 , the SOFC stack  50  is sandwiched between outer end headers (raw material supply layers)  15  containing therein the vaporizers  41  and the reformer  40 . 
     Modified Example 1 
     Next, Modified example 1 of the SOFC hot module  100  of  FIG. 2  will be described with reference to  FIG. 4 .  FIG. 4  is a view schematically showing an example of paths through which air and fluids (raw material and reforming water) flow in the SOFC hot module  100  according the present embodiment. 
     In Modified example 1, in the configuration of the SOFC hot module  100  of  FIG. 2 , the air having been cooled by the heat exchange with the fluid in the second heat exchanger section  12  is guided again to the SOFC stack  50 . Then, in the third heat exchanger section  17 , the air is caused to exchange heat with the SOFC stack  50  again. The air having been heated by the heat exchange with the SOFC stack  50  in the third heat exchanger section  17  is output to a fourth heat exchanger section  18 . In the fourth heat exchanger section  18 , the air is caused to exchange heat with the fluids (at least one of the raw material and the reforming water). 
     That is, the air gains heat in each of the first heat exchanger section  11  and the third heat exchanger section  17  from the SOFC  20 , and then discards the heat by the heat exchange in each of the second heat exchanger section  12  and the fourth heat exchanger section  18 , thereby having a state in which the air will be able to cool substances. The air having a state in which the air will be able to cool the SOFC  20 , is finally supplied to the SOFC  20 . In the SOFC  20 , the air cools the SOFC  20  (main cooling) again when the air is consumed as the oxidizing gas in the cell reaction. 
     As described above, in the SOFC hot module  100  according to Modified example 1 of the present embodiment, the air supplied from outside cools the SOFC  20  in the SOFC stack  50  once. Then, the air having been heated by the heat owned by the SOFC  20  in the SOFC stack  50 , is caused to exchange heat with the fluid (at least one of the raw material and the reforming water) in the second heat exchanger section  12 , and thereby is cooled. The air, from which a portion of its heat has been deprived by the heat exchange in the second heat exchanger section  12 , is guided again to the SOFC stack  50 . The air further cools the SOFC  20  in the SOFC stack  50  by the heat exchange in the third heat exchanger section  17 . Then, the air having been heated by the heat owned by the SOFC  20  in the SOFC stack  50  is guided to the fourth heat exchanger section  18 . In the fourth heat exchanger section  18 , the air is caused to exchange heat with the fluids (at least one of the raw material and the reforming water), and thereby is cooled again. 
     Thereby, the air, from which a portion of its heat has been deprived, is supplied as the oxidant to the cathode  21  in the power generation section, and cools the SOFC  20  again as the cooling medium (main cooling). 
     The fluid having exchanged heat with the air in fourth heat exchanger section  18 , vaporizes the reforming water by utilizing the heat owned by the air and becomes the humidified raw material, which is supplied to the reformer  40 . The reformer  40  generates the reformed gas from the humidified raw material. This reformed gas is supplied as the fuel gas to the anode  22  in the power generation section and cools the SOFC  20  as the cooling medium. 
     From a view point of energy, a portion of the waste heat resulting from the power generation in the SOFC  20  is used as an energy for preheating the fluids, which can reduce the amount of air used for cooling the SOFC  20 . In particular, the air is caused to exchange heat with the SOFC  20  in the first heat exchanger section  11  and in the second heat exchanger section  17 . The air having been heated by this heat exchange transfers the heat obtained from the SOFC  20  to the fluids by the heat exchange with the fluid in the third heat exchanger section  12  and in the fourth heat exchanger section  18 . That is, a portion of the waste heat resulting from the power generation in the SOFC  20  can be efficiently used as the energy for preheating the fluid. 
     Modified Example 2 
     Next, Modified example 2 of the SOFC hot module  100  of  FIG. 2  will be described with reference to  FIG. 5 .  FIG. 5  is a view schematically showing an example of paths through which air and fluids (raw material and reforming water) flow in the SOFC hot module  100  according the present embodiment. 
     The SOFC hot module  100  according to Modified example 2 is different in configuration from the SOFC hot module  100  of  FIG. 2  in that the fluid heated by the heat exchange with the air in the second heat exchanger section  12  is guided to the SOFC stack  50 . In addition, the SOFC hot module  100  according to Modified example 2 is different in configuration from the SOFC hot module  100  of  FIG. 2  in that the fluid guided to the SOFC stack  50  is caused to exchange heat with the SOFC  20  in the SOFC stack  50 , and then is supplied to the reformer  40 . 
     As shown in  FIG. 5 , the SOFC hot module  100  according to Modified example 2 vaporizes the reforming water by utilizing the heat owned by the air having deprived the heat from the SOFC  20  and thereby having been heated, to generate the humidified raw material. In the SOFC hot module  100  according to Modified example 2, the generated humidified raw material deprives the heat from the SOFC  20  in the SOFC stack  50  and thereby is preheated. 
     Since the SOFC hot module  100  is configured as described above, the humidified raw material in addition to the air can be used as the fluids used for directly cooling the SOFC  20 . 
     As described above, in the SOFC hot module  100  according to the present embodiment, the air and the humidified raw material which are supplied to the power generation section in the SOFC  20  can be utilized as the fluids used for directly cooling the SOFC  20 . The combustion section  30  combusts the combustion exhaust gases (anode-off-gas and cathode-off-gas) exhausted from the SOFC  20  to generate heat which can activate the reformer  40 . This means that the SOFC hot module  100  can be operated while utilizing the waste heat resulting from the power generation in the SOFC  20  as the vaporization energy and the reforming energy. Therefore, the amount of the air supplied from outside excessively to cool the SOFC  20  can be reduced, a steam partial pressure (dew point) in the exhaust gas can be increased, and as a result, the water can be supplied in a sustainable manner easily within the system. 
     Modified Example 3 
     Next, Modified example 3 of the SOFC hot module  100  of  FIG. 2  will be described with reference to  FIG. 6 .  FIG. 6  is a view schematically showing an example of paths through which air and fluids (raw material and reforming water) flow in the SOFC hot module  100  according the present embodiment. 
     The SOFC hot module  100  according to Modified example 3 is a combination of the above configuration of Modified example 1 and the above configuration of Modified example 2. In the configuration of the SOFC hot module  100  according to Modified example 1, the fluid having exchanged heat with the air in the fourth heat exchanger section  18  becomes the humidified raw material which is supplied to the reformer  40 , whereas in the SOFC hot module  100  according to Modified example 3, the fluid having exchanged heat with the air in the fourth heat exchanger section  18  becomes the humidified raw material which is guided to the SOFC stack  50 . In addition, in the SOFC stack  50 , the humidified raw material is caused to exchange heat with the SOFC  20  in the fifth heat exchanger section  19 , and the heated humidified raw material is supplied to the reformer  40 . 
     The other configuration is the same as those of the above stated Modified example 1 and Modified example 2, and therefore will not be described in repetition. 
     [Example of Configuration of SOFC Hot Module] 
     Next, a specific example of the configuration of the above stated SOFC hot module  100  will be described with reference to  FIGS. 7 and 8 . In particular, as a specific example of the configuration of the SOFC hot module  100 , the SOFC hot module  100  according to Modified example 3 will be exemplarily described.  FIG. 7  is a front view showing an example of the specific configuration of the SOFC hot module according the present embodiment.  FIG. 8  is a side view showing an example of the specific configuration of the SOFC hot module  100  according the present embodiment. 
     Hereinafter, it is supposed that a surface at a near side in  FIG. 7  in the SOFC hot module  100  of  FIG. 7  is a front surface of the SOFC hot module  100  and a surface at an opposite side of the near side is a back surface of the SOFC hot module  100 . 
     Initially, a specific outer shape of the SOFC hot module  100  of the present embodiment will be described with reference to  FIGS. 7 and 8 .  FIG. 7  is a front view of the SOFC hot module  100 , and  FIG. 8  is a side view of the SOFC hot module  100 . In  FIG. 7 , gaskets for sealing adjacent members are not shown for easier explanation. To clearly show members, a part of the members at a left half part of the SOFC hot module  100  are apart from each other. However, actually, stack members are fastened together by a fastener member  60  such that they are in contact with each other. The SOFC stack  50  of the present embodiment is a flat plate stacked type cell stack in which rectangular SOFCs  20  are stacked together. Therefore, as shown in  FIG. 8 , the SOFC hot module  100  including the flat plate stacked type SOFC stack  50  has a side surface of a substantially square shape, and a front surface of a substantially rectangular shape, which form a rectangular parallelepiped shape. The shape of the SOFC stack  50  is not limited to this flat plate stacked type, but may be other shape such as a cylindrical type. 
     The SOFC stack  50  includes a plurality of SOFCs  20 , a plurality of interconnectors  24 , a cathode end interconnector  241 , and an anode end interconnector  242 . The plurality of SOFCs  20  and the plurality of interconnectors  24  are arranged alternately. The cathode end interconnector  241  is placed at a cathode side terminal end portion, while the anode end interconnector  242  is placed at anode side terminal end portion. More specifically, in a direction from the cathode side (left side in  FIG. 7 ) in  FIG. 7 , the cathode end interconnector  241 , the SOFC  20 , the interconnector  24 , the SOFC  20 , the interconnector  24 , . . . the SOFC  20 , and the anode end interconnector  242  are stacked together in this order. 
     The outer end headers  15 , the cathode end interconnectors  241 , the SOFCs  20 , the interconnectors  24 , and the anode end interconnectors  242  are placed to be oriented vertically such that they are laterally symmetric with respect to the reformers  40  placed at a center. In the example of  FIG. 7 , right and left terminal end portions (outer end portions) of the SOFC hot module  100  are cathode sides. 
     (Flow of Air Flowing Through SOFC Hot Module) 
     Next, the flow of the air flowing through the SOFC hot module  100  will be described with reference to  FIG. 9 .  FIG. 9  is a view showing the flow of the air flowing through the SOFC hot module  100  according the present embodiment. In  FIG. 9 , gaskets for sealing adjacent members are not shown for easier explanation. To clearly show members, a part of the members at a left half part of the SOFC hot module  100  are apart from each other. However, actually, stack members are fastened together by the fastener member  60  such that they are in contact with each other. 
     Initially, the air is supplied to a first air preheating manifold  151  of a reformer connection header (reformer connection layer)  16  via the air inlet  62  (not shown in  FIG. 9 , see  FIG. 16  as described later) provided on a back surface side of the reformer connection header  16 . The air flows through the first air preheating manifolds  151  provided in the corresponding locations of the anode end interconnector  242 , the SOFC  20 , . . . the interconnector  24 , . . . and the cathode end connector  241  and reaches a first turn portion  154  formed at the outer end header  15 . 
     At this time, the air flowing through the first air preheating manifolds  151  deprives the heat owned by the SOFCs  20  to cool the SOFCs  20 , and thereby is heated. Then, in the first turn portion  154  of the outer end header  15 , the flow of the air is turned so that the air is guided from the first air preheating manifold  151  to a second air preheating manifold  152 . 
     The air, a flow of which has been turned, flows through the second air preheating manifolds  152  provided in the corresponding locations of the cathode end interconnector  241 , the SOFC  20 , . . . the interconnector  24 , . . . and the anode end connector  242  and reaches a second turn portion  155  of the reformer connection header  16 . 
     After the air has reached the second turn portion  155 , the flow of the air is turned so that the air is guided to a third air preheating manifold  153 . The air flows through the third air preheating manifolds  153  provided in the corresponding locations of the anode end interconnector  242 , the SOFC  20 , . . . the interconnector  24 , . . . and the cathode end connector  241  and reaches a third turn portion  156  formed at the outer end header  15 . Then, in the third turn portion  156 , the flow of the air is turned so that the air is guided to a cathode entrance manifold  211 . 
     The air having been guided to the cathode entrance manifold  211  is supplied to the cathode end interconnector  241  and to the interconnectors  24  (cathode passages  213   a ,  213   b  as will be described later), and oxygen is consumed in the cathodes  21  (not shown in  FIG. 9 , see  FIG. 13  as will be described later) of the SOFCs  20 . Simultaneously, the air introduced into the cathode entrance manifolds  211  cools the SOFCs  20  and is discharged into a cathode exit manifold  212 . All of the air, oxygen of which has been consumed, finally flows through the anode end interconnector  242  and is discarded in an off-gas mixing section  260  (not shown in  FIG. 9 , see  FIG. 16  as will be described later) of the reformer connection header  16 . 
     In the above series of flow of the air, in the preheating manifolds in the SOFC stack  50 , the air is heated while cooling the SOFC stack  50 , and reaches the outer end header  15  each time. Then, the air discards the heat in the outer end header  15  via heat exchange fins, or the like provided in the turn portions (first turn portion  154 , third turn portion  156 ) of the outer end header  15  and thereby is cooled. Thereby, the air restores its cooling ability and then flows again to cool the SOFC stack  50 . 
     (Flow of Raw Material and Reforming Water Flowing Through SOFC Hot Module) 
     Fluids (raw material and reforming water) supplied to the SOFC hot module  100  flow as follows. Hereinafter, the flow of the fluids (raw material and reforming water) flowing through the SOFC hot module  100  will be described with reference to  FIG. 10 .  FIG. 10  is a view showing an example of flows of the raw material and reforming water flowing through the SOFC hot module  100  according the present embodiment. In  FIG. 10 , gaskets for sealing adjacent members are not shown for easier explanation. To clearly show members, a part of the members at a left half part of the SOFC hot module  100  are apart from each other. However, actually, stack members are fastened together by the fastener member  60  such that they are in contact with each other. 
     Initially, the raw material and the reforming water are supplied to the outer end header  15  via the raw material inlet  61 . In the outer end header  15 , the raw material and the reforming water are supplied to a raw material preheating manifold  157  as will be described later. The reforming water is dropped to the vaporizer  41  (see  FIG. 11  as will be described later) in the outer end header  15 , and is vaporized by the heat obtained from the air supplied to the outer end header  15 . That is, the heat for vaporizing the reforming water is the heat obtained from the SOFC  20  by the air flowing through the above stated preheating manifolds. That is, the reforming water gains the heat deprived from the SOFC  20  by the air via the heat exchange fins provided in the first turn portion  154  and the third turn portion  156 , and thereby is vaporized. The vaporized reforming water and the raw material are mixed to generate a humidified raw material. The humidified raw material flows through raw material preheating manifolds (raw material passages)  157  provided in the corresponding locations of the cathode end interconnector  241 , the SOFC  20 , . . . the interconnector  24 , . . . and the anode end connector  242 , and reaches a raw material preheating manifold  157  as will be described later (humidified raw material receiving hole) f (not shown in  FIG. 10 ) in the reformer connection header  16 . 
     By an operation of the reformer  40  as will be described later, the humidified raw material is steam-reformed into a reformed gas containing hydrogen of about 80%. The reformed gas is introduced into the SOFC stack  50  through the anode entrance manifold  221  via the reformer connection header  16 . 
     The reformed gas (fuel) having been introduced into the SOFC stack  50  is supplied to the anode end interconnector  242  and to the interconnectors  24 , and hydrogen is consumed in the anodes  22  of the SOFCs  20 . Simultaneously, the reformed gas cools the SOFCs  20  and is discharged to anode exit manifolds (discharge pipe)  222 . The reformed gas, hydrogen of which has been consumed finally flows through the anode exit manifold  222  of the anode end interconnector  242 , and is discarded in the off-gas mixing section  260  (see  FIG. 16  as will be described later) of the reformer connection header  16 . 
     Finally, the anode-off-gas and the cathode-off-gas are mixed in the off-gas mixing section  260  into a reformed air-fuel mixture, which is supplied to the combustion section  30  of the reformer  40  via an off-gas manifold (combustion exhaust gas supply hole)  270 . 
     As can be obvious from the series of flow of the fluids as described above, the SOFC hot module  100  of the present embodiment has features that the reforming water is vaporized by the pre-heated air having cooled the SOFC  20 . 
     In the SOFC hot module  100  of  FIGS. 9 and 10 , the first heat exchanger section  11  is implemented as the first air preheating manifold (first air passage)  151 . The third heat exchanger section  17  is implemented as the second air preheating manifold (second air passage)  152  and the third air preheating manifold (second air passage)  153 . The second heat exchanger section  12  is implemented by the first turn portion  154  which exchanges heat with the air, while the fourth heat exchanger section  18  is implemented by the third turn portion  156 . By the heat exchange with the air in the second heat exchanger section  12  and in the fourth heat exchanger section  18 , the heat transferred from the air heats the vaporizer  41 , and as a result heats the fluids (raw material and reforming water) to generate the humidified raw material. 
     That is, when the air is supplied to the SOFC hot module  100 , the air exchanges heat with the SOFCs  20  while flowing through the first air preheating manifolds  151 , the second air preheating manifolds  152 , and the third air preheating manifolds  153 . By this heat exchange, the air cools the SOFCs  20  and thereby is heated (preheated). 
     The heat gained by the heat exchange with the heated air is transferred to the vaporizer  41  via the first turn portion  154  and the third turn portion  156 . By utilizing the transferred heat, the vaporizer  41  vaporizes the reforming water supplied from outside, to generate the mixture gas (humidified raw material) of steam and the raw material. In the SOFC hot module  100 , the heat exchange between the air and the vaporizer  41  occurs via the first turn portion  154  (second heat exchanger section  12 ) and the third turn portion  156  (fourth heat exchanger section  18 ), to heat the vaporizer  41 . However, a member which exchanges heat via the first turn portion  154  (second heat exchanger section  12 ) and the third turn portion  156  (fourth heat exchanger section  18 ) is not limited to the vaporizer  41 . For example, the member may be a manifold provided to preheat the raw material and to flow the raw material. 
     In the configuration of the present embodiment, in which the vaporizer  41  is heated via the first turn portion  154  (second heat exchanger section  12 ) and the third turn portion  156  (fourth heat exchanger section  18 ), a portion of reforming/vaporizing energy is supplied from the heated air and used to vaporize the reforming water, from the perspective of the raw material and the reforming water. In a case where a further temperature increase is allowed by the heat energy supplied from the air, a portion of the reforming energy may be covered by preheating the raw material and the reforming water before they are supplied to the reformer  40 . 
     Next, a description will be given of a detailed structure of the above members (outer end header  15 , cathode end interconnector  241 , SOFC  20 , interconnector  24 , anode end interconnector  242 , reformer connection header  16 , and reformer  40 ) constituting the SOFC hot module  100 . 
     Now, an attention will be focused on a structure of a left half portion relative to the reformer  40  located at the center, in the SOFC hot module  100  of  FIG. 7 . Regarding the outer end header  15 , the cathode end interconnector  241 , the SOFC  20 , the interconnector  24 , and the anode end interconnector  242 , their surfaces of a left end side in  FIG. 7 , of both end portions in a direction in which these members are stacked, are obverse surfaces, and their surfaces of a right end side in  FIG. 7  are reverse surfaces. Also, regarding the outer end header  15 , the cathode end interconnector  241 , the SOFC  20 , the interconnector  24 , and the anode end interconnector  242 , surfaces defining a front surface or a back surface of the SOFC hot module  100  are side surfaces. 
     (Structure of Outer End Header) 
     Firstly, a structure of the outer end header  15  located at the left end in  FIG. 7  will be described with reference to  FIG. 11 .  FIG. 11  is a view showing an example of an obverse surface, a side surface and a reverse surface of the outer end header  15  constituting the SOFC hot module  100  according the present embodiment. 
     The outer end header  15  has a plate shape having a square surface as shown by the obverse surface or the reverse surface of  FIG. 11 . The outer end header  15  is provided on an upper surface thereof with the raw material inlet  61  to receive the reforming water and the raw material. 
     On the reverse surface of the outer end header  15 , there are formed four preheating manifolds enclosing an outer periphery of the reverse surface. In the vicinity of the outer periphery of the reverse surface of the outer end header  15 , there are formed a raw material preheating manifold  157   a  at an upper surface side, a first air preheating manifold  151   a  on a side portion placed at a back surface side of the SOFC hot module  100 , a second air preheating manifold  152   a  on a bottom surface side, and a third air preheating manifold  153   a  on a side portion placed at a front surface side of the SOFC hot module  100 . In a case where these preheating manifolds need not be described such that they are differentiated from each other for the respective members stacked, they will be simply referred to as the raw material preheating manifold  157 , the first air preheating manifold  151 , the second air preheating manifold  152 , and the third air preheating manifold  153 . 
     As described above, the air or the fluids (raw material and reforming water) flow through the preheating manifolds and thereby deprive the heat from the SOFC stack  50  to cool the SOFC stack  50 . By comparison, the air or the raw material gain the heat from the SOFC stack  50 . In view of this, the shape of the preheating manifolds is suitably, for example, an opening shape (comb-shape) provided with a plurality of projections like the cathode end interconnector  241  of  FIG. 12  placed adjacent to the outer end header  15 , so as to have a structure for increasing a contact area in which the preheating manifolds contact the fluid (air or raw material). That is, the structure for increasing the contact area as such a comb shape is preferable so long as it will not cause a significant increase in a pressure loss. 
     In a range from the outer end header  15  to the reformer  40 , the cathode end interconnector  241 , the plurality of SOFCs  20 , . . . , the plurality of interconnectors  24 , . . . , the anode end interconnector  242 , and the reformer connection header  16  are arranged and stacked in this order. The four preheating manifolds are provided in the corresponding locations of the respective members. In a state in which these members are stacked together, through-holes extending in which they are stacked together are formed. 
     As shown in  FIG. 11 , in a lower portion of the raw material preheating manifold  157   a , the vaporizer  41  composed of, for example, steel wool, foamed metal, etc., is provided. The humidified raw material containing the reforming water vaporized by the vaporizer  41  flows through the raw material preheating manifolds  157  in another members stacked together, from the outer end header  15  to the reformer  40 . 
     In the same manner, the first air preheating manifolds  151 , the second air preheating manifolds  152 , and the third air preheating manifold  153  form through-holes extending in the direction in which another members are stacked together, in a state in which another members are stacked together, from the outer end header  15  to the reformer  40 . The air is guided through the through-holes before it is supplied to the cathodes  21 . The air is preheated by the heat owned by the SOFC  20  and deprives the heat from the SOFCs  20  to cool the SOFCs  20 . 
     As shown in  FIG. 11 , on an upper surface side of the second air preheating manifold  152   a , the first turn portion  154  is formed to have a shape in which it extends in the same direction as that of the second air preheating manifold  152   a , and one end thereof is joined to an end portion of the first air preheating manifold  151   a . As described above, the first turn portion  154  is joined at one end thereof to the first air preheating manifold  151   a  and joined at the side portion of the bottom surface side to the second air preheating manifold  152   a . The first turn portion  154  is able to guide the air having flowed through the first air preheating manifold  151 , to the second air preheating manifolds  152 . The first turn portion  154  is provided with a plurality of heat exchange fins arranged horizontally. 
     In a region which is a substantially center portion of the outer end header  15 , which region is surrounded by the four manifolds, the third turn portion  156  is formed. The third turn portion  156  connects the third air preheating manifold  153   a  to a cathode entrance manifold  211   a . The third turn portion  156  is able to guide the air having flowed through the third air preheating manifold  153   a  to the cathode entrance manifold  211   a . The third turn portion  156  is provided with a plurality of heat exchange fins arranged horizontally. 
     (Structure of Cathode End Interconnector) 
     Next, a structure of the cathode end interconnector  241  placed adjacently to the outer end header  15  will be described with reference to  FIG. 12 .  FIG. 12  is a view showing an example of an obverse surface, a side surface and a reverse surface of the cathode end interconnector  241  constituting the SOFC hot module  100  according the present embodiment. 
     As shown in  FIG. 12 , the cathode end interconnector  241  also serves as a current collecting member and is provided on its upper surface with a positive electrode. To enable the cathode end interconnector  241  to also serve as the current collecting member in this way, the cathode end interconnector  241  is designed so that a thickness of a side surface is greater than that of the normal interconnector  24  (e.g., see  FIG. 7 ). 
     On a peripheral portion of the obverse surface of the cathode end interconnector  241 , like the outer end header  15 , there are formed manifolds (first air preheating manifold  151   b , second air preheating manifold  152   b , third air preheating manifold  153   b , and raw material preheating manifold  157   b ). As described above, these manifolds are provided as through holes formed in locations corresponding to those of the manifolds provided in the outer end header  15  in a state in which the cathode end interconnector  241  and the outer end header  15  are stacked together such that they have the same shapes and penetrate to the reverse surface. 
     In addition, a cathode entrance manifold  211   b  is formed such that it is placed inward relative to the four manifolds enclosing the outer periphery, is located in the vicinity of the first air preheating manifold  151   b , and extends substantially in parallel with the first air preheating manifold  151   b . The cathode entrance manifold  211   b  penetrates from the obverse surface of the cathode end interconnector  241  to the reverse surface of the cathode end interconnector  241 . 
     On an outer peripheral portion of the reverse surface of the cathode end interconnector  241 , like the obverse surface, there are formed a first air preheating manifold  151   b , a second air preheating manifold  152   b , a third air preheating manifold  153   b , and a raw material preheating manifold  157   b . In addition, like the obverse surface, the cathode entrance manifold  211   b  is provided. Furthermore, on the reverse surface, a cathode exit manifold  212   a  is provided in the vicinity of a third air preheating manifold  153   b  such that it extends substantially in parallel with the third air preheating manifold  153   b . As shown in  FIG. 12 , the cathode exit manifold  212   a  is provided in a location opposed to the cathode entrance manifold  211   b . Between the cathode exit manifold  212   a  and the cathode entrance manifold  211   b , a cathode passage  213   a  formed by a number of pores is provided. 
     (Structure of SOFC) 
     Next, a structure of the SOFC  20  placed adjacently to the cathode end interconnector  241  will be described with reference to  FIG. 13 .  FIG. 13  is a view showing an example of an obverse surface, a side surface and a reverse surface of SOFC  20  constituting the SOFC hot module  100  according the present embodiment. 
     As shown in  FIG. 13 , the SOFC  20  includes the cathode  21  on the obverse surface and the anode  22  on the reverse surface such that an electrolyte is sandwiched between the cathode  21  and the anode  22 . The cathode  21  and the anode  22  implement the heat generation section of the present invention. On an outer peripheral portion of the obverse surface of the SOFC  20 , there are formed a first air preheating manifold  151   c , a second air preheating manifold  152   c , a third air preheating manifold  153   c , and a raw material preheating manifold  157   c , like the cathode end interconnector  241  (see  FIG. 12 ) adjacent to the SOFC  20 . These manifolds are formed as through-holes in locations corresponding to those of the manifolds formed in the cathode end interconnector  241  adjacent to the SOFC  20  in a state in which the SOFC  20  and the cathode end interconnector  241  are stacked together such that they have the same shapes and penetrate to the reverse surface. 
     As shown in  FIG. 13 , the SOFC  20  is provided with a cathode entrance manifold  211   c  and a cathode exit manifold  212   b  as through-holes formed in locations corresponding to those of the cathode entrance manifold  211   b  and the cathode exit manifold  212   a  formed on the reverse surface of the cathode end interconnector  241  (see  FIG. 12 ) in a state in which the SOFC  20  and the cathode end interconnector  241  are stacked together such that they have the same shapes and penetrate to the reverse surface. 
     In the vicinity of the second air preheating manifold  152   c , an anode entrance manifold  221   a  is formed to extend substantially in parallel with the second air preheating manifold  152   c . The anode entrance manifold  221   a  penetrates from the obverse surface to the reverse surface. In the vicinity of the raw material preheating manifold  157   c , an anode exit manifold  222   a  is formed to extend substantially in parallel with the raw material preheating manifold  157   c . The anode exit manifold  222   a  penetrates from the obverse surface to the reverse surface. 
     As shown in  FIG. 13 , on the obverse surface of the SOFC  20 , a cathode entrance manifold  211   c  and a cathode exit manifold  212   b  are placed at opposed locations with respect to the cathode  21  in a horizontal direction. In addition, on the obverse surface of the SOFC  20 , the anode entrance manifold  221   a  and the anode exit manifold  222   a  are placed at opposite locations with respect to the cathode  21  in a vertical direction. 
     Therefore, the supplied air flows from the cathode entrance manifold  211   c  toward the cathode exit manifold  212   b  on the obverse surface of the SOFC  20  (cathode  21 ). By comparison, the reformed gas (hydrogen) generated by reforming the raw material flows from the anode entrance manifold  221   a  toward the anode exit manifold  222   a  on the reverse surface of the SOFC  20 . At this time, the anode  22  is supplied with the reformed gas through pores of a base plate  250 . 
     That is, the SOFC  20  of the present embodiment is a metal-support-cell (MSC) created by forming the base plate  250  by porous metal (porous ferrite based stainless plate). For example, the SOFC  20  may be a general electrolyte-support cell (ESC) or an anode-support cell (ASC). 
     However, in these types, a peripheral portion is made of a very thin ceramics. It is therefore difficult to form corrugated manifolds as shown in  FIG. 13 , in the peripheral portion of the SOFC  20 . Also, there is a fear that the peripheral portion will be damaged in a period during which the temperature is raised up to a cell operation temperature. 
     To avoid this, in the SOFC  20  of the present embodiment, the MSC is used as described above. The MSC is formed in such a manner that the base plate  250  is made of a porous ferrite based stainless plate (e.g., powdered sintered body manufactured by Crofer 22APU, Thyssenkrupp Co., Ltd.), and catalysts and electrolytes are stacked between the cathode  21  and the anode  22  of  FIG. 7  and integrated. The above stated manifolds are processed easily on portions of the base plate  250  to have desired shape. The MSC is manufactured in such a manner that layers of catalysts and electrolytes which are several tens micrometers in thickness are formed inside of a thickness of 1 mm of a base member. The overall MSC is a metal which is very high in heat conductivity, in terms of a heat property. Because of this, in a configuration in which the heat generating section is present inside of the SOFC  20 , the heat can be transferred efficiently to the overall SOFC  20 . Even in a case where a cooling structure (heat exchange structure) is present only in the outer peripheral portion of the SOFC  20 , the overall SOFC  20  can be suitably cooled. 
     (Structure of Interconnector) 
     Next, a structure of the interconnector  24  placed adjacently to the SOFC  20  will be described with reference to  FIG. 14 .  FIG. 14  is a view showing an example of an obverse surface, a side surface and a reverse surface of the interconnector  24  constituting the SOFC hot module  100  according the present embodiment. 
     As shown in  FIG. 14 , like the SOFC  20  (see  FIG. 13 ) adjacent to the interconnector  24 , there are formed a first air preheating manifold  151   d , a second air preheating manifold  152   d , a third air preheating manifold  153   d , and a raw material preheating manifold  157   d . These manifolds are formed as through-holes in locations corresponding to those of the manifolds formed in the outer peripheral portion of the SOFC  20  adjacent to the interconnector  24  in a state in which the SOFC  20  and the interconnector  24  are stacked together such that they have the same shapes and penetrate to the reverse surface. 
     Like the SOFC  20 , there are formed a cathode entrance manifold  211   d , a cathode exit manifold  212   c , an anode entrance manifold  221   b  and an anode exit manifold  222   b.    
     On the obverse surface of the interconnector  24 , in a region surrounded by the cathode entrance manifold  211   d , the cathode exit manifold  212   c , the anode entrance manifold  221   b , and the anode exit manifold  222   b , an anode passage  223   a  composed of a plurality of pores is formed. The anode passage  223   a  is configured such that the pores are continuous from the anode entrance manifold  221   b  to the anode exit manifold  222   b.    
     On the reverse surface of the interconnector  24 , in a region surrounded by the cathode entrance manifold  211   d , the cathode exit manifold  212   c , the anode entrance manifold  221   b , and the anode exit manifold  222   b , a cathode passage  213   b  composed of a plurality of pores is formed. The cathode passage  213   b  is configured such that the pores are continuous from the cathode entrance manifold  211   c  to the cathode exit manifold  212 C. 
     (Structure of Anode End Interconnector) 
     A structure of the anode end interconnector  242  placed at an anode-side terminal end portion of the SOFC stack  50  will be described with reference to  FIG. 15 .  FIG. 15  is a view showing an example of an obverse surface, a side surface and a reverse surface of the anode end interconnector  242  constituting the SOFC hot module  100  according the present embodiment. 
     As shown in  FIG. 15 , the anode end interconnector  242  is provided on an upper surface with as a negative current collecting terminal member. To enable the anode end interconnector  242  to also serve as the current collecting member, like the cathode end interconnector  241 , the anode end interconnector  242  is designed so that its thickness is greater than that of the interconnector  24  (e.g., see  FIG. 7 ). 
     On the outer peripheral portion of the anode end interconnector  242 , there are formed a first air preheating manifold  151   e , a second air preheating manifold  152   e , a third air preheating manifold  153   e , and a raw material preheating manifold  157   e  such that these manifolds penetrate to the reverse surface. These manifolds are formed as through-holes in locations corresponding to those of the first air preheating manifold  151   c , the second air preheating manifold  152   c , the third air preheating manifold  153   c , and the raw material preheating manifold  157   c  formed in the SOFC  20  (see  FIG. 13 ) adjacent to the anode end interconnector  242  in a state in which the SOFC  20  and the anode end interconnector  242  are stacked together such that they have the same shapes and penetrate to the reverse surface. 
     In addition, there are formed an anode entrance manifold  221   c  and an anode exit manifold  222   c  in locations corresponding to those of the anode entrance manifold  221   a  and the anode exit manifold  222   a  of the SOFC  20  adjacent to the anode end interconnector  242  in a state in which the SOFC  20  and the anode end interconnector  242  are stacked together. These manifolds have the same shapes as those of the anode entrance manifold  221   a  and the anode exit manifold  222   a , and penetrate from the obverse surface of the anode end interconnector  242  to the reverse surface of the anode end interconnector  242 . 
     Furthermore, in the location corresponding to that of the cathode exit manifold  212   b  of the SOFC  20  adjacent to the anode end interconnector  242  in a state in which the SOFC  20  and the anode end interconnector  242  are stacked together, there is formed a cathode exit manifold  212   d  having the same shape as that of the cathode exit manifold  212   b . Note that as shown in  FIG. 15 , the cathode exit manifold  212   d  penetrates from the obverse surface to the reverse surface in a range of a substantially upper half portion thereof, but does not penetrate from the obverse surface to the reverse surface in a range of a substantially lower half portion thereof such that it forms a groove (counter boring). This is because in the reformer connection header  16  placed following the cathode end interconnector  242 , the off-gas manifold  270  (see  FIG. 16  as will be described later) as will be described later is formed in a location corresponding to that of the substantially lower half portion thereof in a state in which the SOFC  20  and the anode end interconnector  242  are stacked together. Therefore, in the anode end interconnector  242 , the cathode-off-gas is supplied to the combustion section  30  only from the penetrating portion of the cathode exit manifold  212   d.    
     (Structure of Reformer Connection Header) 
     Next, a structure of the reformer connection header  16  placed adjacently to the anode end interconnector  242  will be described with reference to  FIG. 16 .  FIG. 16  is a view showing an example of an obverse surface, a side surface and a reverse surface of the reformer connection header  16  constituting the SOFC hot module  100  according the present embodiment. 
     As described above with reference to  FIG. 7 , for example, the reformer connection header  16  is a stack member for connecting the SOFC stack  50  to the reformer  40 . As shown  FIG. 16 , the reformer connection header  16  is provided with an air inlet  62  on a back side surface thereof. The air supplied from the air inlet  62  flows through the first air preheating manifold  151  penetrating toward the outer end header  15 , and is preheated by heat of the SOFC  20  while flowing through the first air preheating manifold  151 . 
     On the outer peripheral portion of the obverse surface of the reformer connection header  16 , there are formed a first air preheating manifold  151   f , a second air preheating manifold  152   f , a second turn portion  155 , and a raw material preheating manifold (humidified raw material supply hole)  157   f.    
     In a location corresponding to that of the first air preheating manifold  151   e  of the anode end interconnector  242  (see  FIG. 15 ) adjacent to the reformer connection header  16  in the state in which the anode end interconnector  242  and the reformer connection header  16  are stacked together, the first air preheating manifold  151   f  having the same shape as that of the first air preheating manifold  151   e  is formed. In a location corresponding to that of the second air preheating manifold  152   e  of the anode end interconnector  242  in a state in which the anode end interconnector  242  and the reformer connection header  16  are stacked together, the second air preheating manifold  152   f  having substantially the same shape is formed. Furthermore, in a location corresponding to that of the third air preheating manifold  153   e  of the anode end interconnector  242  in a state in which the anode end interconnector  242  and the reformer connection header  16  are stacked together, the second turn portion  155  having substantially the same shape is formed. An end portion of the second turn portion  155  and an end portion of the second air preheating manifold  152   f  are joined together. Because of this, the air having flowed through the second air preheating manifold  152   f  is guided to the third air preheating manifold  153   e  of the anode end interconnector  242  via the second turn portion  155 . 
     In a location corresponding to that of the raw material preheating manifold  157   e  of the anode end interconnector  242  in a state in which the anode end interconnector  242  and the reformer connection header  16  are stacked together, the raw material preheating manifold  157   f  having the same shape is formed. 
     In the reformer connection header  16 , only the raw material preheating manifold  157   f  penetrates from the obverse surface to the reverse surface, of the manifolds and the second turn portion  155  provided on the outer peripheral portion. 
     In the reformer connection header  16 , in locations corresponding to those of the anode entrance manifold  221   c  and the anode exit manifold  222   c  of the anode end interconnector  242  in a state in which the anode end interconnector  242  and the reformer connection header  16  are stacked together, there are formed an anode entrance manifold (reformed gas supply hole)  221   d  and an anode exit manifold  222   d  having the same shapes. Only the anode entrance manifold  221   d  penetrates to the reverse surface to receive the fuel gas generated through the reforming reaction from the reformer  40 . 
     In a location corresponding to that of the penetrating portion of the cathode exit manifold  212   d  of the anode end interconnector  242  in a state in which the anode end interconnector  242  and the reformer connection header  16  are stacked together, there is formed a cathode exit manifold  212   e  having the same shape as that of the penetrating portion. In a location corresponding to that of the non-penetrating portion of the cathode exit manifold  212   d  of the anode end interconnector  242  in a state in which the anode end interconnector  242  and the reformer connection header  16  are stacked together, there is formed an off-gas manifold  270  penetrating to the reverse surface. 
     The anode exit manifold  222   d , the cathode exit manifold  212   e , and the off-gas manifold  270  are connected together via an off-gas mixing section  260  provided in a center portion of the reformer connection header  16 . An anode-off-gas exhausted from the anode exit manifold  222   d  and the cathode-off-gas exhausted from the cathode exit manifold  212   d  are mixed in the off-gas mixing section  260 , and the resulting mixture gas is exhausted to the combustion section  30  via the off-gas manifold  270 . 
     As will be described in detail later, to prevent a flame ignited by an igniter  34  inside of the reformer  40  of  FIG. 17  from spreading to inside of the SOFC stack  50 , a backfire preventing member  261  is provided between the anode exit manifold  222   d  and the off-gas mixing section  260 , and a backfire preventing member  262  is provided between the off-gas manifold  270  and the off-gas mixing section  260 . The backfire preventing member  261  is implemented by a backfire preventing net such as a metal net, or a punching metal. 
     (Structure of Reformer) 
     Next, a structure of the reformer  40  placed adjacently to the reformer connection header  16  will be described with reference to  FIG. 17 .  FIG. 17  is a view showing an example of an obverse surface, a side surface and a reverse surface of the reformer  40  constituting the SOFC hot module  100  according the present embodiment. 
     As shown in  FIG. 17 , on a cathode side of a side surface of a front surface side of the reformer  40 , the igniter  34  which is an electronically-controlled ignition device is provided instead of the burner  31 . In addition, on a cathode side of a side surface of a back surface side of the reformer  40 , the exhaust port  63  is provided to exhaust an exhaust gas from inside of the SOFC hot module  100  to outside. 
     On the obverse surface side of the reformer  40 , the combustion section  30  is provided. On the reverse surface side of the reformer  40 , a reforming reaction proceeds by combustion heat from the combustion section  30 . As shown in  FIG. 17 , on the obverse surface side of the reformer  40 , on an outer peripheral portion at an upper surface side thereof, i.e., in a location corresponding to the raw material preheating manifold  157   f  (see  FIG. 16 ) of the reformer connection header  16  adjacent to the reformer  40  in a state in which the reformer connection header  16  and the reformer  40  are stacked together, there is formed a raw material preheating manifold  157   g  penetrating to the reverse surface. On an outer peripheral portion of a lower portion of the obverse surface of the reformer  40 , i.e., in a location corresponding to that of the anode entrance manifold  221   d  of the reformer connection header  16  in a state in which the reformer connection header  16  and the reformer  40  are stacked together, there is formed an anode entrance manifold (reformed gas exhaust hole)  221   e  penetrating to the reverse surface. 
     As shown in  FIG. 17 , the raw material preheating manifold  157   g  and the anode entrance manifold (reformed gas exhaust hole)  221   e  extend horizontally in parallel between the front surface side and the back surface side of the reformer  40 . Between the raw material preheating manifold  157   g  and the anode entrance manifold  221   e , there are provided a plurality of combustion catalysts  33  arranged in an inverted-S shape when viewed from the obverse surface. At a right end portion (front surface side) in  FIG. 17 , in a portion where the combustion catalysts  33  are placed, a combustion catalyst holding member  32  for securing these combustion catalysts  33  is provided. 
     The combustion section  30  is configured in such a manner that the igniter  34  ignites a reformed mixture gas (anode-off-gas and cathode-off-gas) exhausted from the off-gas manifold  270  (see  FIG. 16 ) of the reformer connection header  16  adjacent to the reformer  40 , to heat the combustion catalysts  33 . 
     On the reverse surface of the reformer  40 , reforming catalysts  43  are arranged in a substantially-S shape from the raw material preheating manifold  157   g  to the anode entrance manifold  221   e , and constitute the reforming section  44 . In a boundary portion between the reformer  44  and the anode entrance manifold  221   e , there is provided a reforming catalyst holding member  42  to prevent the reforming catalysts  43  from migrating and clogging the anode entrance manifold  221   e . The reforming catalyst holding member  42  is implemented by, for example, a punching metal, etc. 
     That is, the raw material supplied through the raw material preheating manifold  157   g  is generated into hydrogen through the reforming reaction in a reforming section  44  heated, and guided as the reformed gas to the anode  22  of the SOFC  20  of the SOFC stack  50  via the anode entrance manifold  221   e.    
     Typically, as these manifolds, only reaction gas passages (manifolds) such as the cathode entrance manifold  211 , the cathode exit manifold  212 , the anode entrance manifold  221  and the anode exit manifold  222  are provided inside of the SOFC stack  50 . However, in the SOFC hot module  100  of the present embodiment, as described above, on an outer peripheral portion which is outward relative to these manifolds, the plurality of air preheating manifolds (the first air preheating manifold  151 , the second air preheating manifold  152 , and the third air preheating manifold  153 ) and the raw material preheating manifold  157  are provided. The air or the raw material flows through the preheating manifolds and thereby deprives the heat from the SOFC stack  50 . The air or the raw material is heated by the heat owned by the SOFC stack  50 . 
     (Operation Associated with Reforming Reaction) 
     Next, an operation associated with the reforming reaction in the reformer  40  will be described in greater detail. The reformer connection header  16  and the reformer  40  which are placed adjacently are mechanically connected to each other by fastening using the fastener member  60 . As described above, the reformed mixture gas (anode-off-gas and cathode-off-gas) exhausted from the off-gas manifold  270  of the reformer connection header  16  is supplied to the combustion section  30  of the reformer  40 . The humidified raw material exhausted from the raw material preheating manifold  157   f  of the reformer connection header  16 , is supplied to the reforming section  44  via the raw material preheating manifold  157   g  of the reformer  40  (see  FIG. 17 ). 
     As shown in  FIG. 17 , the reformer  40  is one kind of heat exchanger as a whole, in which the combustion section  30  and the reforming section  44  are placed with a thin separating wall between them. The reformer  40  is configured to conduct reforming in the reforming section  44  on the opposed surface by utilizing a combustion energy of the reformed mixture gas generated by the combustion in the combustion section  30 . 
     The reformed mixture gas introduced through a lower end of the combustion section  30  is ignited by the igniter  34  and introduced into the combustion catalysts  33  inside of the combustion section at start of the operation of the SOFC. Note that this ignition operation becomes unnecessary at a time point when a reformer temperature is stabilized and catalytic combustion starts automatically. 
     The reformed mixture gas is combusted continuously in the combustion section  30 , and the resulting combustion heat is supplied to the reforming section  44  on the opposed surface (reverse surface). An exhaust gas of the reformed mixture gas is discarded through the exhaust port  63  provided on the back surface side of the SOFC hot module  100  in a location corresponding to the upper end portion of the combustion section  30 . 
     The humidified raw material introduced to the upper end side of the reforming section  44  via the raw material preheating manifold  157   g  goes through the steam reforming continuously on the reforming catalysts  43  and is generated into hydrogen. The generated hydrogen is supplied as the reformed gas to the reformer connection header  16  via the anode entrance manifold  221   e . A flow of the reformed gas which occurs thereafter has already been described. 
     The reformer connection header  16  and the reformer  40  shown in  FIGS. 16 and 17  can be manufactured easily by grinding a metal block. Or, the reformer connection header  16  and the reformer  40  can be manufactured easily by a powder metallurgical technology for pressurizing and sintering metal powder. In the case of mass production of the reformer connection header  16  and the reformer  40  in view of manufacturing cost, the latter manufacturing method is preferable. The outer end header  15 , the cathode end interconnector  241 , the interconnector  24 , and the anode end interconnector  242 , which are the other stack members, are manufactured as in the reformer connection header  16  and the reformer  40 . 
     The reformer connection header  16  and the reformer  40  shown in  FIGS. 16 and 17  have relatively great contact surfaces, which enables direct heat transmission from the reformer connection header  16  to the reformer  40 . This leads to utilization of the waste heat resulting from the power generation in the SOFC  20  as the reforming energy, and further reduction of excessive air, which makes it easier to supply the water in a self-sustainable manner. 
     Hereinafter, a principle in which the water can be supplied in a self-sustainable manner in the SOFC hot module  100  according to the present embodiment will be described. 
     (Self-Sustainable Supply of Water) 
     Prior to explaining the principle in which water can be supplied in a self-sustainable manner, a configuration of a SOFC system  200  which includes the SOFC hot module  100  and can utilize condensed water generated from the exhaust gas as the reforming water will be described with reference to  FIG. 18 .  FIG. 18  is a view schematically showing an example of a configuration of the SOFC system  200  according the present embodiment. 
     As shown in  FIG. 18 , the SOFC system  200  according the present embodiment is configured to further include a condensation heat exchanger  70  and a drain tank  71  in addition to the above stated SOFC hot module  100 . The SOFC system  200  is configured in such a manner that the condensation heat exchanger  70  exchanges heat between the exhaust gas exhausted from the SOFC hot module  100  and the air, to cool the exhaust gas to generate the condensed water, which is stored in the drain tank  71 . The condensed water stored in the drain tank  71  is utilized as the reforming water in the SOFC hot module  100 . 
     The SOFC system  200  according the present embodiment can gain the condensed water of a required amount as the reformed water from the exhaust gas cooled by the heat exchange in the condensation heat exchanger  70  based on a principle described below. 
     Hereinafter, the principle in which water can be supplied in a self-sustainable manner will be described, with reference to supply and generation of substances in  FIGS. 19 to 21 .  FIGS. 19 to 21  are views showing an example of supply and generation of substances in a reforming efficiency and a fuel/oxygen utilization efficiency, in a cell reaction in which water of 1 mol is generated from hydrogen of 1 mol and oxygen of 0.5 mol.  FIG. 19  shows the relationships of the supply and generation of substances in a case where the oxygen utilization ratio Uo=0.2,  FIG. 20  shows the relationships of the supply and generation of substances in a case where the oxygen utilization ratio Uo=0.3, and  FIG. 21  shows the relationships of the supply and generation of substances in a case where the oxygen utilization ratio Uo=0.33. 
     When a combustion energy of hydrogen of a flow rate 1.0 mol/min is expressed as a work amount, this is 4129 W. Therefore, a power generation amount of the fuel cell operated with a power generation efficiency of 60% by consuming hydrogen of a flow rate 1.0 mol/min and oxygen of a flow rate 0.5 mol/min is 4129×0.6=2477 W In this case, a heat generation amount is 4129×0.4=1651 W. That is, the SOFC system  200  is required to be operated while removing the heat of 1651 W to keep a cell temperature at a constant temperature. 
     As can be clearly seen from  FIG. 19 , in a case where the raw material is methane (CH 4 ) and S/C=2.5, the reforming water of 0.98 mol per consumed hydrogen of 1 mol is required. When vaporization heat of the water of 0.98 mol/min is expressed as a work amount, this is 664 W. 
     As descried above, in the conventional configuration, to remove the heat of 1651 W, a fuel cell apparatus was operated while cooling the SOFC with the air which was five times (Uo=0.2) as much as sctoichiometry. In the conventional configuration, the condensed water generated by cooling the exhaust gas at an outside air temperature of 35 degrees C. in summer season which is assumed normally is 0.78 mol/min. Therefore, the reforming water of 0.98 mol/min cannot be covered. 
     On the other hand, in the fuel cell of the present embodiment, 664 W (40%) of 1651 W can be consumed as the vaporization heat of the water. An amount of heat to be cooled by the air is 60% of the above, i.e., three times (Uo=0.33) as much as sctoichiometry. Supply and generation of the substances in this case are shown in  FIG. 21 . When the exhaust gas is cooled at an outside air temperature of 35 degrees C. in summer season which is assumed normally, condensed water of 1.07 mol/min can be generated. That is, the generated condensed water can cover the reforming water of 0.98 mol/min which is a required amount. As a result, the fuel cell apparatus of the present embodiment is able to gain the condensed water of a required amount as the reforming water by cooling the exhaust gas with the air in a range of the outside air temperature which is assumed normally. That is, the fuel cell apparatus of the present embodiment is able to supply the water in a self-sustainable manner. 
     Numeral modifications and alternative embodiments of the present invention will be apparent to those skilled in the art in view of the foregoing description. Accordingly, the description is to be construed as illustrative only, and is provided for the purpose of teaching those skilled in the art the best mode of carrying out the invention. The details of the structure and/or function may be varied substantially without departing from the spirit of the invention. 
     INDUSTRIAL APPLICABILITY 
     A high-temperature operating fuel cell module and a high-temperature operating fuel cell system of the present invention are useful as a high-temperature operating fuel cell module, etc., which can improve a utilization efficiency of air supplied. 
     REFERENCE SIGNS LIST 
     
         
           9  air outlet 
           10  air preheating section 
           11  first heat exchanger section 
           12  second heat exchanger section 
           13  supply header 
           14  discharge header 
           15  outer end header 
           16  reformer connection header 
           17  third heat exchanger section 
           18  fourth heat exchanger section 
           19  fifth heat exchanger section 
           20  SOFC 
           21  cathode 
           22  anode 
           23  electrolyte 
           24  interconnector 
           25  base pipe member 
           30  combustion section 
           31  burner 
           32  combustion catalyst holding member 
         combustion catalyst 
           34  igniter 
           40  reformer 
           41  vaporizer 
           42  reforming catalyst holding member 
           43  reforming catalyst 
           44  reforming section 
           45  reformed gas inlet 
           50  SOFC stack 
           60  fastener member 
           61  raw material inlet 
           62  air inlet 
           63  exhaust port 
           70  condensed water heat exchanger 
           71  drain tank 
           100  SOFC hot module 
           151  first air preheating manifold 
           151   a  first air preheating manifold 
           151   b  first air preheating manifold 
           151   c  first air preheating manifold 
           151   d  first air preheating manifold 
           151   e  first air preheating manifold 
           151   f  first air preheating manifold 
           152  second air preheating manifold 
           152   a  second air preheating manifold 
           152   b  second air preheating manifold 
           152   c  second air preheating manifold 
           152   d  second air preheating manifold 
           152   e  second air preheating manifold 
           152   f  second air preheating manifold 
           153  third air preheating manifold 
           153   a  third air preheating manifold 
           153   b  third air preheating manifold 
           153   c  third air preheating manifold 
           153   d  third air preheating manifold 
           153   e  third air preheating manifold 
           154  first turn portion 
           155  second turn portion 
           156  third turn portion 
           157  raw material preheating manifold 
           157   a  raw material preheating manifold 
           157   b  raw material preheating manifold 
           157   c  raw material preheating manifold 
           157   d  raw material preheating manifold 
           157   e  raw material preheating manifold 
           157   f  raw material preheating manifold 
           157   g  raw material preheating manifold 
           200  SOFC system 
           211  cathode entrance manifold 
           211   a  cathode entrance manifold 
           211   b  cathode entrance manifold 
           211   c  cathode entrance manifold 
           212  cathode exit manifold 
           212   a  cathode exit manifold 
           212   b  cathode exit manifold 
           212   c  cathode exit manifold 
           212   d  cathode exit manifold 
           212   e  cathode exit manifold 
           213   a  cathode passage 
           213   b  cathode passage 
           221  anode entrance manifold 
           221   a  anode entrance manifold 
           221   b  anode entrance manifold 
           221   c  anode entrance manifold 
           221   d  anode entrance manifold 
           221   e  anode entrance manifold 
           222  anode exit manifold 
           222   a  anode exit manifold 
           222   b  anode exit manifold 
           222   c  anode exit manifold 
           222   d  anode exit manifold 
           223   a  anode passage 
           223   b  anode passage 
           241  cathode end interconnector 
           242  anode end interconnector 
           250  base plate 
           260  off-gas mixing section 
           261  backfire preventing member 
           270  off-gas manifold 
           1000  SOFC hot module