Abstract:
Disclosed is a power generating module which generates electric power by using fuel, including: an accommodating section to accommodate a fuel container to store fuel; a power generating section to perform power generation by using the fuel in the fuel container; and a controlling section to allow, after an amount of the fuel in the fuel container accommodated in the accommodating section becomes less than a predetermined amount necessary for the power generation in the power generating section, at least a portion of a by-product generated in a process of the power generation in the power generating section to be collected into the fuel container containing less than the predetermined amount of the fuel.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a power generating module which generates electric power by being supplied with fuel from a fuel container and an electronic device. 
         [0003]    2. Description of the Related Art 
         [0004]    Lately, small electronic devices such as cellular phones, laptop computers, digital cameras, watches, and PDAs (Personal Digital Assistance) are achieving great advancements and developments. As power sources for electronic devices, primary cells such as alkaline cells and manganese cells or secondary cells such as nickel-cadmium cells, nickel-hydrogen cells and lithium ion cells are used. Lately, as an alternative to primary cells and secondary cells, the research and development of fuel cells, which enable high energy use efficiency, are being actively done. 
         [0005]    A fuel cell is to convert chemical energy into electrical energy by an electrochemical reaction of fuel and oxygen in the air. Since fuel cells use an electrochemical reaction in which the chemical energy of the fuel is directly converted to electrical energy, water is produced and discharged as a by-product of the reaction. 
         [0006]    For example, a fuel cell system of Japanese Patent Application Laid-open Publication No. 2004-192171, a cartridge for collecting water is separately provided as well as a fuel cartridge. 
       SUMMARY OF THE INVENTION 
       [0007]    As described above, when a cartridge for collecting water is provided separately from a fuel cartridge, the fuel cartridge and the cartridge to which water has collected needed to be changed separately. 
         [0008]    The present invention has been made in consideration of the above situation, and is successful in providing a power generating module and an electronic device in which a by-product can be easily collected in a fuel container. 
         [0009]    According to a first aspect of the present invention, there is provided a power generating module which generates electric power by using fuel, comprising: 
         [0010]    an accommodating section to accommodate a fuel container to store fuel; 
         [0011]    a power generating section to perform power generation by using the fuel in the fuel container; and 
         [0012]    a controlling section to allow, after an amount of the fuel in the fuel container accommodated in the accommodating section becomes less than a predetermined amount necessary for the power generation in the power generating section, at least a portion of a by-product generated in a process of the power generation in the power generating section to be collected into the fuel container containing less than the predetermined amount of the fuel. 
         [0013]    In the above-mentioned power generating module, the controlling section may allow the by-product collected in the fuel container to be supplied to the power generating section for the power generation in the power generating section. 
         [0014]    The above-mentioned power generating module may further comprise a collector to collect the by-product generated by the power generation, 
         [0015]    and the controlling section may allow a surplus portion of the by-product from the collector to be collected into the fuel container containing less than the predetermined amount necessary for the power generation. 
         [0016]    In the above-mentioned power generating module, the fuel container containing less than the predetermined amount necessary for the power generation may be substantially empty. 
         [0017]    The above-mentioned power generating module may further comprise a reacting section to reform the fuel of the fuel container. 
         [0018]    In the above-mentioned power generating module, the controlling section prevents at least the portion of the by-product from being collected into the fuel container until the amount of the fuel in the fuel container becomes less than the predetermined amount. 
         [0019]    An electronic device may comprise: 
         [0020]    the above-mentioned power generating module. 
         [0021]    According to a second aspect of the present invention, there is provided a power generating module which generates electric power by using fuel, comprising: 
         [0022]    an accommodating section to accommodate a plurality of fuel containers to store fuel; 
         [0023]    a power generating section to perform power generation by using the fuel in the fuel containers; and 
         [0024]    a controlling section to allow, after an amount of the fuel in one of the plurality of fuel containers accommodated in the accommodating section becomes less than a predetermined amount necessary for the power generation in the power generating section, at least a portion of a by-product generated in a process of the power generation in the power generating section to be collected into the one of the plurality of fuel containers containing less than the predetermined amount of the fuel. 
         [0025]    In the above-mentioned power generating module, the controlling section may allow the by-product collected in the fuel container to be supplied to the power generating section for the power generation in the power generating section. 
         [0026]    The above-mentioned power generating module may further comprise a collector to collect the by-product generated by the power generation, 
         [0027]    and the controlling section may allow a surplus portion of the by-product from the collector to be collected into the fuel container containing less than the predetermined amount necessary for the power generation. 
         [0028]    In the above-mentioned power generating module, the fuel container containing less than the predetermined amount necessary for the power generation may be substantially empty. 
         [0029]    The above-mentioned power generating module may further comprise a reacting section to reform the fuel of the fuel container. 
         [0030]    In the above-mentioned power generating module, the controlling section prevents at least the portion of the by-product from being collected into any of the plurality of fuel containers until the amount of the fuel in one of the plurality of fuel containers becomes less than the predetermined amount. 
         [0031]    An electronic device may comprise: 
         [0032]    the above-mentioned power generating module. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0033]    The present invention will become more fully understood from the following detailed description with the accompanying drawings and are explanatory only, and thus are not intended as a definition of the limits of the present invention, and wherein; 
           [0034]      FIG. 1  is an exploded perspective view of a fuel container  100 ; 
           [0035]      FIG. 2A  is a top view of the fuel container  100 ; 
           [0036]      FIG. 2B  is a sectional view taken along cross-section line II-II; 
           [0037]      FIG. 3  is a block diagram showing a schematic structure of a power generating system  300 ; 
           [0038]      FIG. 4  is a flow chart showing switching operation processing of a flow path switching section; 
           [0039]      FIG. 5A  is a top view of an electronic device  400 ; 
           [0040]      FIG. 5B  is a bottom view of the electronic device  400  of  FIG. 5A ; 
           [0041]      FIG. 5C  is a rear view of the electronic device  400  of  FIG. 5A ; 
           [0042]      FIG. 6  is an exploded perspective view of a fuel container  500 ; 
           [0043]      FIG. 7A  is a top view of a fuel container  500 ; 
           [0044]      FIG. 7B  is a sectional view taken along cross-section line VII-VII; 
           [0045]      FIG. 8A  is a top view of the electronic device  800 ; 
           [0046]      FIG. 8B  is a right side view of the electronic device  800  of  FIG. 8A ; and 
           [0047]      FIG. 8C  is a rear view of the electronic device  800  of  FIG. 8A . 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0048]    The best mode for carrying out the present invention will be explained below with reference to the drawings. The scope of the invention is not limited to the illustrated embodiments. 
       First Embodiment 
       [0049]      FIG. 1  is an exploded perspective view of a fuel container  100 ,  FIG. 2A  is a top view of the fuel container  100 , and  FIG. 2B  is a sectional view taken along cross-section line II-II. 
         [0050]    A fuel container  100  can be removably connected to a power generating module  200  (see  FIG. 3 ) in the accommodating section of the power generating module  200  which accommodates the fuel container  100 , and includes a fuel storing section  1  which stores fuel  12 . The fuel storing section  1  cools and collects discharge including gas and water discharged from the power generating module  200  which generates power with the fuel  12  supplied from the fuel storing section  1 . 
         [0051]    The fuel storing section  1  is a box-shaped space which is formed in a box-shaped case  4 . The fuel  12  is chemical fuel alone or a mixture of chemical fuel and water, and as chemical fuel, compounds including hydrogen atoms, for example, alcohols such as methanol, ethanol, etc., ethers such as dimethyl ether, etc., and gasoline may be used. In this embodiment, chemical fuel such as methanol is to be used. As mixtures of chemical fuel and water, for example, a uniform mixture of methanol and water is used as a chemical reaction material. The fuel storing section  1  is used as a water collecting section in order to collect water, which is a by-product, after finishing discharge of the fuel  12 . 
         [0052]    The case  4  is transparent or semitransparent and is, for example, made of a synthetic resin material, such as polyethylene, polypropylene, polycarbonate, and acryl. 
         [0053]    On an end surface in a longitudinal direction of the case  4  (right end surface  4 A in  FIG. 2 ), a fuel discharge opening  11 , which discharges the fuel  12  to the power generating module  200 , is formed in a convex shape projecting outward from the right end surface  4 A by penetrating the end surface  4 A so as to be in communication with the inside of the fuel storing section  1 . 
         [0054]    The fuel discharge opening  11 , which is provided at a cap of a convex projecting from the right end surface  4 A of the case  4 , is a through hole for discharging out the fuel  12  in the fuel storing section  1  and a check valve (not shown) is fitted therein for preventing the fuel from being discharged out through the fuel discharge opening  11  from the fuel storing section  11  unnecessarily. Concretely, the check valve is a duckbill valve formed in a duckbill shape with a material having flexibility and elasticity. The check valve is fitted in the fuel discharge opening  11  so that a tip end of the duckbill shape faces the inside of the fuel storing section  1 . Examples of the material having flexibility and elasticity are ethylene propylene diene monomer rubber (EPDM) and butyl rubber. Generally, butyl rubber shows low gas permeability among elastic polymers and thus, it is preferable to select the butyl rubber in practical use in order to make a component smaller. Since the check valve does not have a mechanically complicated structure, the volume and cost thereof can be reduced. The check valve may be provided in advance with an insertion hole which communicates the inside and outside of the fuel storing section  1  when a needle-shaped fuel supply tube (not shown), which is provided in the later-described power generating module  200 , is inserted in order to supply the fuel  12  from the fuel container  100 . Alternatively, the insertion hole may be formed by inserting the fuel supply tube. When the insertion hole is provided in advance, the check valve is designed so that force is applied around the insertion hole in the direction of closing the insertion hole due to an internal pressure of the fuel  12  inside the fuel storing section  1  if the inside of the fuel storing section  1  is filled with fuel  12 . Due to the restoring force by elasticity, the check valve is forced to return to its original shape, thus no gap is formed around the fuel supply tube inserted in the insertion hole. Consequently, no fuel leaks out of the fuel storing section  1  from the insertion hole unnecessarily. By inserting the fuel supply tube of the power generating module  200 , the fuel  12  is discharged from the fuel storing section  1  to the power generating module  200  through the fuel discharge opening  11 , and through the fuel supply tube. 
         [0055]    A convex-shaped discharge collecting opening  41  which communicates with the inside of the fuel storing section  1  and collects the discharge which is discharged from the later-described power generating module  200  is provided in a buried manner on the right end surface  4 A of the case  4  at the upper side of the fuel discharge opening  11 . 
         [0056]    The discharge collecting opening  41 , which is provided at a cap of a convex projecting from the right end surface  4 A of the case  4 , is a through hole for collecting discharge into the fuel storing section  1  and check valve (not shown) is fitted therein so that once discharge is supplied to the inside of the case  4  through the discharge collecting opening  41 , the discharge is prevented from being discharged out from the case  4  unnecessarily. Concretely, the same check valve as the check valve fitted in the above-described fuel discharge opening  11  may be used. A discharge sending tube  42  is provided in the discharge collecting opening  41  for supplying discharge into the fuel storing section  1  through the check valve. The discharge sending tube  42  is laid on the lower side from the discharge collecting opening  41  and extends toward a left end of the fuel storing section  1  along the longitudinal direction of the case  4 . 
         [0057]    A rectangular opening  43  which communicates to the inside of the fuel storing section  1  is formed on the other end surface (left end surface in  FIG. 2 ) in the longitudinal direction of the case  4 . A gas-liquid separation film  2  which includes a hydrophobic porous film with a gas-liquid separation function is attached so as to cover the opening  43 . The gas-liquid separation film  2  which is permeable to gas but not permeable to liquid is a rectangular thin film and is made of polyethylene, polypropylene, polyacrylonitrile, polymethylmethacrylate, cellulosic resin such as cellulose acetate and cellulose triacetate, polysulfone resin such as polyether sulfone and polysulfone, etc. Thus, gas may pass between inside and outside of the case  4  through the gas-liquid separation film  2  but liquid may not pass through the gas-liquid separation film  2 . Thus, water inside the case  4  does not leak outside. When water is collected into the case  4  as discharge from the discharge collecting opening  41 , air inside the case  4  which corresponds to the collected water in volume is discharged outside through the gas-liquid separation film  2 . 
         [0058]    Guides  44  and  44  are attached to a front surface  4 C and a rear surface  4 D respectively at the left end side of the case  4  for removably attaching the case  4  to a later-described electronic device  400 . The guides  44  and  44  extend on the front surface  4 C and the rear surface  4 D straight in a horizontal direction. 
         [0059]    The fuel  12  inside the fuel storing section  1  of the above-described fuel container  100  is supplied to the later-described power generating module  200  through the fuel discharge opening  11  and the fuel  12  is used to generate electric energy. When the fuel  12  in the fuel storing section  1  runs out, the discharge which is produced in the power generating module  200  is sent through the discharge collecting opening  41  to the discharge sending tube  42 , then flows through the discharge sending tube  42  to be sent to the fuel storing section  1 . The water vapor in the gas of the discharge is cooled while flowing in the discharge sending tube  42 , or cooled by the collected water in the fuel storing section  1  and is condensed to water, and thus collected in the fuel storing section  1 . The gas which was not condensed is released outside through the gas-liquid separation film  2  and the condensed water, since it is liquid, cannot pass through the gas-liquid separation film  2  and is accumulated in the fuel storing section  1 . 
         [0060]      FIG. 3  is a block diagram showing a schematic structure of a power generating system  300  comprising a first fuel container  100 A and a second fuel container  100 B which have the same structure as the above described fuel container  100  and a power generating module  200 . In the description below, each component comprising the first fuel container  100 A corresponds to each component of the above described fuel container  100 , thus the letter A will be applied to the same reference numerals, and as for the second fuel container  100 B, the letter B will be applied to the same reference numerals. 
         [0061]    The power generating system  300  comprises an accommodating section which accommodates a first fuel container  100 A and a second fuel container  100 B, and a power generating module  200  which generates power by the fuel  12  supplied from the first and second fuel containers  100 A and  100 B. In the power generating system  300 , the power generating module  200  generates power by taking in the fuel  12  from either one of the fuel containers  100 A and  100 B selected from the first and second fuel containers  100 A and  100 B. When the power generating module  200  generates power, the power generating module  200  continues to take in the fuel  12  until the selected fuel container  100 A or  100 B becomes empty, and when the selected container becomes empty then switches and takes in the fuel  12  from the other fuel container  100 A or  100 B. The power generating module  200  which has taken in the fuel  12  discharges water, and the water is collected in the water tank (collector)  201  in the power generating module  200 . The water tank  201  has an acceptable amount which can store not less than the amount of water generated and discharged by the amount of the fuel  12  when at least one fuel container  100 A or  100 B is full. Thus when the water collected by the water tank  201  is a predetermined amount (for example, 50 ml) or more and less than the acceptable amount (for example, 70 ml), either one of the fuel containers  100 A or  100 B is surely empty of the fuel  12 . At this time, the surplus water in the water tank  201  after deducting the amount of water necessary for the vaporizer  211  at starting up and the amount of water necessary for the first humidifier  221  and the second humidifier  222  to humidify at starting up (for example 10 ml) is collected in the fuel storing section ( 1 A or  1 B) of the fuel container ( 100 A or  100 B) which is empty of the fuel  12  and the amount of water in the water tank  201  is controlled so as to include the amount necessary at starting up. The control may be done so that the water collected in the fuel storing section ( 1 A or  1 B) is reused for power generation. 
         [0062]    The power generating module  200  comprises a water tank  201  which stores water, a reactor  210  which generates hydrogen from the fuel  12  supplied from the first and second fuel containers  100 A and  100 B and the water supplied from the water tank  201 , and a power generating section  220  which includes a fuel cell which generates electric energy by electrochemical reaction of hydrogen. The power generating module  200  also comprises a first humidifier  221  which humidifies the hydrogen generated in the reactor  210  and supplies the hydrogen to the anode of the power generating section  220  and a second humidifier  222  to humidify air supplied to the cathode of the power generating section  220 . The electrolyte film of the power generating section  220  is in a humidified state by the air and reformed gas humidified by the first humidifier  221  and the second humidifier  222 . It is preferable that the timing of beginning the supply of water to the first humidifying section  221  and the second humidifying section  222  is just before the power generating section  220  starts generating power, and the period of supplying water may be during the power generation of the power generating section  220  or if the water generated when the power generating section  220  generates power permeates the entire electrolyte film, the water may be supplied only just before the start of the power generation. 
         [0063]    In the water tank  201 , water is stored and the later-described first water pump P 1  and the second water pump P 2  supplies the stored water to the vaporizer  211  of the reactor  210  and to the first and second humidifiers  221  and  222 . As described later, the discharge (water) which is discharged from the cathode of the power generating section  220  is stored in the water tank  201 . The surplus water of the power generating section  220  which was not humidified and discharged by the first and second humidifying section  221  and  222  is also stored in the water tank  201 . 
         [0064]    The water tank  201  is provided with a remaining water amount sensor S 1  which detects the amount of the remaining water stored in the water tank  201 . The remaining water amount sensor S 1  measures the remaining amount of water stored in the water tank  201  and outputs an electric signal which is the measured result to the controlling section  230 . 
         [0065]    The power generating module  200  is provided with a first remaining amount sensor S 21  and a second remaining amount sensor S 22 . When the first fuel container  100 A and  100 B are connected to the power generating module  200 , the first remaining amount sensor S 21  measures the remaining amount of the fuel  12  stored in the first fuel container  100 A then outputs an electric signal which is the measured result to the controlling section  230  and the second remaining amount sensor S 22  measures the remaining amount of the fuel  12  stored in the second fuel container  100 B then outputs an electric signal which is the measured result to the controlling section  230 . 
         [0066]    According to the remaining amount information signal of the first remaining amount sensor S 21  and the second remaining amount sensor S 22 , the controlling section  230  detects the fuel container between the first fuel container  100 A and  100 B in which the fuel  12  is less than the predetermined amount necessary for power generation (for example an empty state with no remaining amount). Then, when the amount of water in the water tank  201  is a predetermined amount which is a threshold or more and less than the acceptable amount, the controlling section  230  sends the surplus water to the fuel storing section ( 1 A or  1 B) of the fuel container ( 100 A or  100 B) in which the fuel  12  has become less than the predetermined amount necessary for power generation. Once the controlling section  230  puts water into the fuel storing section ( 1 A or  1 B) of the fuel container ( 100 A or  100 B) in which the fuel  12  has become less than the predetermined amount necessary for power generation, the controlling section  230  recognizes the remaining amount measured by the remaining amount sensor (S 21  or S 22 ) from then on is the remaining amount of water, and as described below, as long as there is collected water in the fuel storing section ( 1 A or  1 B) of the fuel container ( 100 A or  100 B) the water in the fuel storing section is supplied with higher priority than the water in the water tank  201  to the vaporizer  211 , the first humidifier  221  and the second humidifier  222 . When the remaining amount sensor (S 21  or S 22 ) determines that the water in the fuel container ( 100 A or  100 B) is empty, it is switched so that the water tank  201  supplies the water to the vaporizer  211 , the first humidifier  221  and the second humidifier  222 . 
         [0067]    The reactor  210  comprises an vaporizer  211  which generates fuel gas (a mixture gas of evaporated fuel and water vapor) by evaporating the fuel  12  and the water supplied from the first fuel container  100 A, the second fuel container  100 B, and the water tank  201 , a reformer  212  which generates reformed gas by reforming the fuel gas supplied from the vaporizer  211  as shown in the chemical reaction formula (1), a catalytic combustor  213  which heats the reformer  212  in order to set the reformer  212  to a temperature necessary for performing the reaction of the chemical reaction formula (1) well, and a carbon monoxide remover  214  (CO remover) which oxidizes and removes as shown in the chemical reaction formula (3) the trace amount of carbon monoxide which is generated as a by-product of the chemical reaction formula (2) which sequentially occurs after the chemical reaction ( 1 ). The reactor  210  also comprises a heater which also serves as a thermometer (not shown) so as to function as an electric heater to heat the vaporizer  211 , the combustor  213 , and the carbon monoxide remover  214  and to also function as a thermometer in order to measure the temperature of these reacting devices. 
         [0000]      CH 3 OH+H 2 O→3H 2 +CO 2   (1) 
         [0000]      H 2 +CO 2 →H 2 O+CO  (2) 
         [0000]      2CO+O 2 →2CO 2   (3) 
         [0068]    The first humidifier  221  humidifies the hydrogen in the reformed gas generated from the carbon monoxide remover  214  with the water supplied from the water tank  201  and supplies the hydrogen to the anode of the power generating section  220 . 
         [0069]    The second humidifier  222  humidifies the air supplied from the air pump PA with the water supplied from the water tank  201  or the water collected in the fuel storing section ( 1 A or  1 B) of the fuel container ( 100 A or  100 B) and supplies the air to the cathode of the power generating section  220 . The unnecessary water discharged from the second humidifier  222  is to be collected in the water tank  201 . 
         [0070]    The power generating section  220  comprises an anode which supports a catalyst particle, a cathode which supports a catalyst particle, and a film-shaped solid high polymer electrolyte film which intervenes between the anode and the cathode. The anode of the power generating section  220  is supplied with hydrogen supplied from the carbon monoxide remover  214  and the cathode of the power generating section  220  is supplied with air from the outside by the later-described air pump PA. In the anode, the hydrogen in the mixture gas separates to a hydrogen ion and an electron under an action of the catalyst particle of the anode as shown in an electrochemical reaction formula (4). The hydrogen ion is conducted to the cathode through the solid high polymer electrolyte film, and the electron is taken out by the anode as electric energy (generated power). In the cathode, the electron which moved to the cathode, the oxygen in the air, and the hydrogen ion which passed through the solid high polymer electrolyte film reacts and generates water. The offgas which includes the hydrogen unreacted in the anode is sent to the combustor  213 , and the water generated in the cathode and the air unreacted in the cathode is sent to the water tank  201  as discharge. 
         [0000]      H 2 →2H + +2 e   −   (4) 
         [0000]      2H + +½O 2 +2 e   − →H 2 O  (5) 
         [0071]    Besides the first and second fuel containers  100 A and  100 B, the water tank  201 , the reactor  210 , the power generating section  220 , etc., the power generating system  300  comprises a first fuel pump P 31  which supplies the fuel  12  in the first fuel container  100 A to the vaporizer  211  and a second fuel pump P 32  which supplies the fuel  12  in the second fuel container  100 B to the vaporizer  211 . The power generating system  300  comprises a first water pump P 1  which supplies the water in the water tank  201  to the vaporizer  211 , a second water pump P 2  which supplies the water selected between the collected water in the fuel storing section ( 1 A or  1 B) of the fuel container ( 100 A or  100 B) and the water in the water tank  201  to the first and second humidifier  221  and  222 , a third water pump P 3  which sends the water collected in the water tank  201  to the first or second fuel container  100 A or  100 B, a fourth water pump P 4  which supplies and reuses the water collected in the fuel storing section  1 A of the first fuel container  100 A to the vaporizer  211  through a flow path switching section R 1 , and a fifth water pump P 5  which supplies and reuses the water collected in the fuel storing section  1 B of the second fuel container  100 B to the vaporizer  211  through a flow path switching section R 2 . The power generating system  300  comprises an air pump PA to introduce air into the power generating system  300  from the outside. 
         [0072]    A first valve V 1  is connected to the first fuel pump P 31  and the second fuel pump P 32  and a first flow meter F 1  is connected to the first valve V 1 . The first valve V 1  is provided between the vaporizer  211  and the first and second fuel pumps P 31  and P 32 , and the open/close action blocks or allows the flow of the fuel  12  from the first fuel pump P 31  to the vaporizer  211  and blocks or allows the flow of the fuel  12  from the second fuel pump P 32  to the vaporizer  211 . The first flow meter F 1  is provided between the first valve V 1  and the vaporizer  211  and measures the flow rate of the fuel  12  which passes the first valve V 1 . The controlling section  230  allows only either one of the first fuel pump P 31  or the second fuel pump P 32  to operate and controls the first valve V 1  so as to maintain the flow rate of the first flow meter F 1  to a certain level. 
         [0073]    The fuel discharge opening  11  of the first fuel container  100 A is connected to the flow path switching section R 1 . When according to the detection of the remaining amount by the first remaining amount sensor S 21  the fuel  12  in the fuel storing section  1 A is determined to be remaining, the flow path switching section R 1  switches the flow path to the first fuel pump P 31 . When the water is collected in the fuel storing section  1 A after the fuel  12  in the fuel storing section  1 A is determined to be less than the predetermined amount necessary for power generation, the flow path switching section R 1  switches the flow path to the fourth water pump P 4 . 
         [0074]    Similarly, the fuel discharge opening  11  of the second fuel container  100 B is connected to the flow path switching section R 2 . When according to the detection of the remaining amount by the second remaining amount sensor S 22  the fuel  12  in the fuel storing section  1 B is determined to be remaining, the flow path switching section R 2  switches the flow path to the second fuel pump P 32 . When the water is collected in the fuel storing section  1 B after the fuel  12  in the fuel storing section  1 B is determined to be less than a predetermined amount necessary for power generation, the flow path switching section R 2  switches the flow path to the fifth water pump P 5 . 
         [0075]    A second valve V 2  is connected to the first water pump P 1  and a second flow meter F 2  is connected to the second valve V 2 . The second valve V 2  is provided between the first water pump P 1  and the vaporizer  211  and the open/close action blocks or allows the flow of the water from the first water pump P 1  to the vaporizer  211 . The second flow meter F 2  is provided between the second valve V 2  and the vaporizer  211  and measures the flow rate of the water which passes the second valve V 2 . The fuel  12  discharged from the first valve V 1  and the water discharged from the second valve V 2  is mixed before reaching the reactor  210 . When there is no collected water in the fuel storing section ( 1 A or  1 B) of the fuel container ( 100 A or  100 B) in which the fuel  12  is less than the predetermined amount necessary for power generation, the controlling section  230  controls the first water pump P 1  and the second valve V 2  so as to supply the water in the water tank  201  to the vaporizer  211 . The discharge from the combustor  213  (water, gas including water vapor, offgas, etc.) is sent to the water tank  201 . 
         [0076]    The second water pump P 2  is connected to the later-described flow path switching section R 3  and flow path switching section R 4 , and is also connected to the first humidifier  221  and the second humidifier  222 , and the water from the flow path switching section R 3  or the flow path switching section R 4  is supplied to the first humidifier  221  and the second humidifier  222 . 
         [0077]    The third water pump P 3 , a third valve V 3 , and a flow path switching section R 5  are connected between the water tank  201  and the fuel storing section  1 A of the first fuel container  100 A and between the water tank  201  and the fuel storing section  1 B of the second fuel container  100 B. The first remaining amount sensor S 21  and the second remaining amount sensor S 22  perform measurements of the remaining amounts of the fuel  12  and when there is a fuel container ( 100 A or  100 B) in which the fuel  12  is less than the predetermined amount necessary for power generation, the flow path switching section R 5  switches the flow path exclusively so that the fuel container ( 100 A or  100 B) with less than the predetermined amount is in communication with the third valve V 3  and the fuel container ( 100 B or  100 A) in which the fuel  12  is not less than the predetermined amount necessary for power generation is not in communication with the third valve V 3 . When the remaining amount of water in the water tank  201  detected by the remaining water amount sensor S 1  is a predetermined amount or more and less than the acceptable amount, the third water pump P 3  and the third valve V 3  operates and sends water from the water tank  201  to the fuel storing section ( 1 A or  1 B) of the fuel container ( 100 A or  100 B) in which the fuel  12  is less than the predetermined amount necessary for power generation. It is preferable that the amount of water left in the water tank  201  after the water is sent is a sum of the amount of water necessary for the vaporizer  211  at starting up and the amount of water necessary for the first humidifier  221  and the second humidifier  222  to humidify at starting up. Thus, the water is not collected beyond the acceptable amount in the water tank  201 . 
         [0078]    The flow path switching section R 1  is connected to the flow path in communication with the first fuel pump P 31  and the flow path in communication with the fourth water pump P 4  and the flow path switching section R 3 . In a state in which the fuel  12  is discharged from the fuel storing section  1 A of the fuel container  100 A, the flow path switching section R 1  is set so that the flow path of the fuel  12  discharged from the fuel discharge opening  11  is in communication with the first fuel pump P 31 . When the vaporizer  211  and the power generating section  220  continue to operate after the fuel  12  discharged from the fuel storing section  1 A of the fuel container  100 A is less than the predetermined amount necessary for power generation and the water is collected in the fuel container  100 A with less than the predetermined amount necessary for power generation, the controlling section  230  switches the flow path switching section R 1  so that the flow path of the water discharged from the fuel discharge opening  11  is connected to the flow path connected to the fourth water pump P 4  and the flow path switching section R 3 . 
         [0079]    The flow path switching section R 2  is connected to the flow path in communication with the second fuel pump P 32  and the flow path in communication with the fifth water pump P 5  and the flow path switching section R 4 . In a state in which the fuel  12  is discharged from the fuel storing section  1 B of the fuel container  100 B, the flow path switching section R 2  is set so that the flow path of the fuel  12  discharged from the fuel discharge opening  11  is in communication with the second fuel pump P 32 . When the vaporizer  211  and the power generating section  220  continues to operate after the fuel  12  discharged from the fuel storing section  1 B of the fuel container  100 B is less than the predetermined amount necessary for power generation and the water is collected in the fuel container  100 B with less than the predetermined amount necessary for power generation, the controlling section  230  switches the flow path switching section R 2  so that the flow path of the water discharged from the fuel discharge opening  11  is connected to the fifth water pump P 5 . 
         [0080]    A sixth valve V 6  is connected to the fourth water pump P 4  and the fifth water pump P 5  and a third flow meter F 3  is connected to the sixth valve V 6 . The sixth valve V 6  is provided between the vaporizer  211  and the fourth and fifth water pump P 4  and P 5  and the open/close action blocks or allows the flow of the water from the fourth or fifth water pump P 4  and P 5  to the vaporizer  211 . The third flow meter F 3  is provided between the sixth valve V 6  and the vaporizer  211  and measures the flow rate of the water which passes the sixth valve V 6 . The fuel  12  discharged from the first valve V 1  and the water discharged from the sixth valve V 6  is mixed before reaching the reactor  210 . 
         [0081]    The flow path switching section R 3  is further connected to the water tank  201  and the second water pump P 2 . In a state in which it is determined that the fuel  12  exists in the fuel storing section  1 A and the power generating section  220  is generating power or just before starting the power generation, the flow path switching section R 3  connects the water tank  201  so as to be in communication with the second water pump P 2  to supply the water in the water tank  201  to the first humidifier  221  and the second humidifier  222 . In a state in which it is determined that the water exists in the fuel storing section  1 A and the power generating section  220  is generating power or just before starting the power generation, the flow path switching section R 3  switches the flow path so that the water collected in the fuel storing section  1 A is sent to the second water pump P 2  to supply the water to the first and second humidifiers  221  and  222 . 
         [0082]    The flow path switching section R 4  is further connected to the water tank  201  and the second water pump P 2 . In a state in which it is determined that the fuel  12  exists in the fuel storing section  1 B and the power generating section  220  is generating power or just before starting the power generation, the flow path switching section R 4  connects the water tank  201  so as to be in communication with the second water pump P 2  to supply the water in the water tank  201  to the first humidifier  221  and the second humidifier  222 . In a state in which it is determined that the water exists in the fuel storing section  1 B and the power generating section  220  is generating power or just before starting the power generation, the flow path switching section R 3  switches the flow path so that the water collected in the fuel storing section  1 A is sent to the second water pump P 2  to supply the water to the first and second humidifiers  221  and  222 . 
         [0083]    A fourth valve V 4 , a fifth valve V 5 , and the second humidifier  222  are connected to the air pump PA. The fourth valve V 4  is provided between the air pump PA and the carbon monoxide remover  214  and the open/close action blocks or adjusts the flow of the air from the air pump PA to the carbon monoxide remover  214 . 
         [0084]    The fifth valve V 5  is provided between the air pump PA and the combustor  213  and the open/close action blocks or adjusts the flow of the air from the air pump PA to the combustor  213 . 
         [0085]    The first to fifth water pumps P 1  to P 5 , the first fuel pump P 31 , the second fuel pump P 32  and the air pump PA are electrically connected to the controlling section  230  through drivers D 1  to D 5 , D 31 , D 32 , and D 4 . The controlling section  230  comprises, for example a general-purpose CPU (Central Processing Unit), RAM (Random Access Memory) and ROM (Read Only Memory). The controlling section  230  sends control signals to the first to fifth water pumps P 1  to P 5 , the first fuel pump P 31 , the second fuel pump P 32  and the air pump PA and controls the pumping action (including the adjustment of the sending amount) of the first to fifth water pumps P 1  to P 5 , the first fuel pump P 31 , the second fuel pump P 32  and the air pump PA. 
         [0086]    The flow path switching sections R 1  to R 4  are electrically connected to the controlling section  230 . The first to sixth valves V 1  to V 6  are electrically connected to the controlling section  230  through drivers D 11  to D 16 . The first to third flow meters F 1  to F 3  are electrically connected to the controlling section  230 . The controlling section  230  can recognize the flow rate of the fuel  12  and the water by receiving the results measured by the first to third flow meters F 1  to F 3 . The controlling section  230  can also control the open/close action (including the adjustment of the opening size) of the first to sixth valve V 1  to V 6  and the switching operation of the flow path switching section R 5  so that between the fuel storing section  1 A of the first fuel container  100 A and the fuel storing section  1 B of the second fuel container  100 B the fuel storing section in which the fuel  12  is less than the predetermined amount necessary for power generation is selected and the discharge (water) which is discharged from the power generating module  200  is collected in the selected fuel storing section. 
         [0087]    The vaporizer  211 , the reformer  212 , the combustor  213  and the electric heater which heats the carbon monoxide remover  214  are electrically connected to the controlling section  230  through a driver D 21 . The controlling section  230  controls the heating value and stopping the operation of the electric heater and is able to detect the temperature of the reactors, which are the vaporizer  211 , the reformer  212 , the combustor  213  and the carbon monoxide remover  214 , by measuring the resistance value of the electric heater which changes according to the temperature. When the reactor  210  is started, the electric heater heats the vaporizer  211 , the reformer  212 , the combustor  213 , and the carbon monoxide remover  214  to an appropriate temperature and after the combustor  213  starts combustion and can stably apply heat, the operation of the electric heater may be stopped or the heating amount by the electric heater may be reduced. 
         [0088]    The first and second remaining amount sensor S 21  and S 22  and the remaining water amount sensor S 1  are electrically connected to the controlling section  230 . The controlling section  230  determines whether the first and second fuel containers  100 A and  100 B are attached and detects the remaining amount of the fuel  12  which is measured by the first remaining amount sensor S 21  and the remaining amount of the fuel  12  which is measured by the second remaining amount sensor S 22 . Then the controlling section  230  controls the power generating system  300  so that when each remaining amount is less than the predetermined amount necessary for power generation, the power generating system  300  is not started or the operation stops, and when the remaining amount is not less than the predetermined amount necessary for power generation, the power generating system  300  is started or the operation is maintained. 
         [0089]    When the power generating system  300  is started, according to the remaining amount result of the fuel  12  by the first and second remaining amount sensors S 21  and S 22 , if the fuel  12  remains in both fuel containers  100 A and  100 B, the controlling section  230  supplies the fuel  12  from either one of the fuel containers, and if one of the fuel containers is less than the predetermined amount necessary for power generation, the controlling section  230  supplies the fuel  12  from the other fuel container ( 100 A or  100 B) with the predetermined amount of the fuel  12  necessary for power generation remaining. 
         [0090]    A DC/DC converter  240  is connected to the power generating section  220  and an external power source, that is an external device (load) which can operate by receiving power supply from the power generating system  300  is connected to the DC/DC converter  240 . The DC/DC converter  240  is a device which converts a voltage output from the power generating section  220  to a predetermined voltage according to the standard of the external electronic device so as to output to an external electronic device. The DC/DC converter  240  is connected to the controlling section  230  and the controlling section  230  can detect the input power input from the power generating section  220  to the DC/DC converter  240 . 
         [0091]    A secondary cell  241  is connected to the DC/DC converter  240 . For example, the secondary cell  241  stores surplus electric energy obtained from the power generating section  220  and when the power generating section  220  stops generating electric energy, the secondary cell  241  can supply the power to the external electronic device as a substitute for power generating section  220 . At starting up, the controlling section  230 , the drivers, the sensors and the electric heater of the reactor  210  are electrically driven by a portion of the output from the secondary cell  241  through the DC/DC converter  240 , and are electrically driven by a portion of the output from the power generating section  220  through the DC/DC converter  240  when the output of the power generating section  220  becomes a stable state. 
         [0092]    The power generating system  300  comprising the above structure is attached in an electronic device (external electronic device) such as a desktop personal computer, a laptop personal computer, a cellular phone, a PDA (Personal Digital Assistant), an electronic organizer, a watch, a digital still camera, a digital video camera, a game machine, or a household appliance, as a power source in order to operate the external electronic device. 
         [0093]    Next, the operation of the power generating system  300  is described. 
         [0094]    The power generating system  300  is activated by input of an activating signal to the controlling section  230  through the communication terminal and communication electrode from the external electronic device. Thus, the controlling section  230  activates the first water pump P 1 , the second water pump P 2 , and the air pump PA, and also allows the electric heater to generate heat through the driver D 21 . While the power generating system  300  is in operation, according to the data of the temperature fed back from the electric heaters, the controlling section  230  controls the temperature of the electric heaters so as to maintain it at a predetermined temperature. Even if one of the fuel containers ( 100 A or  100 B) in which the fuel has become less than the predetermined amount of fuel necessary for power generation is filled with water, the water tank  201  stores water of the amount necessary for the vaporizer  211  at starting up, and the amount necessary for the first and second humidifiers  221  and  222  to humidify at starting up. The above-described necessary amount of water is the least amount of water which enables continuous supply of water to the vaporizer  211 , the first humidifier  221  and the second humidifier  222  until water generated in the power generating section  220 , etc., is supplied to the water tank  201  after starting. 
         [0095]    The controlling section  230  controls the switching operation of the third valve V 3  as described below.  FIG. 4  is a flow chart showing switching operation processing of a flow path switching section. 
         [0096]    First, the controlling section  230  confirms whether the first fuel container  100 A and the second fuel container  100 B are attached to the power generating module  200  respectively (step S 1 ). It is determined whether at least either one of the fuel containers ( 100 A or  100 B) is attached (step S 2 ), and when neither of the fuel containers ( 100 A or  100 B) is attached, an error notification of “no fuel container” is given (step S 3 ). When at least one of the fuel containers ( 100 A or  100 B) is attached, the first remaining amount sensor S 21  and the second remaining amount sensor S 22  detect the remaining amounts of the fuel  12  (step S 4 ). At this time, the remaining amount of fuel  12  of the fuel container  100 A or the fuel container  100 B which is not attached is considered to be less than the amount (predetermined amount) of fuel enough to perform power generation by the power generating section  220 . However, the water generated in the power generating section  220 , etc., is not sent to the side where the fuel container is not attached. 
         [0097]    Then, it is determined whether the remaining amounts of the fuel  12  in both of the first and second fuel containers  100 A and  100 B is less than the predetermined amount enough to perform power generation (step S 5 ). When the remaining amounts of the fuel  12  in both of the first and second fuel containers  100 A and  100 B are less than the predetermined amount, an error notification of “exchange fuel container” is given (step S 6 ). When both of the first and second fuel containers  100 A and  100 B are attached and the remaining amount of the fuel  12  of at least one of the fuel containers ( 100 A or  100 B) is not less than the predetermined amount, it is determined whether the remaining amount of the fuel  12  in the first fuel container  100 A is less than the predetermined amount necessary for power generation (step S 7 ). When the remaining amount of the fuel  12  in the fuel container  100 A is less than the predetermined amount necessary for power generation, the first fuel container  100 A is selected as the water collecting container (step S 8 ), and the flow path switching section R 5  switches the flow path exclusively so that the fuel container  100 A is in communication with the third valve V 3  and the fuel container  100 B does not communicate with the third valve V 3  (step S 9 ). 
         [0098]    In step S 7 , when the remaining amount of the fuel  12  in the first fuel container  100 A is not less than the predetermined amount necessary for power generation, it is determined whether the remaining amount of the fuel  12  in the second fuel container  100 B is less than the predetermined amount necessary for power generation (step S 10 ). When the remaining amount of the fuel  12  in the second fuel container  100 B is less than the predetermined amount necessary for power generation, the second fuel container  100 B is selected as the water collecting container (step S 11 ), and the flow path switching section R 5  switches the flow path exclusively and connects the third valve V 3  to the second fuel container  100 B so that the fuel container  100 B is in communication with the third valve V 3  and the fuel container  100 A is not in communication with the third valve V 3  (step S 12 ). 
         [0099]    In step S 10 , when the remaining amount of the fuel  12  in the second fuel container  100 B is not less than the predetermined amount necessary for power generation, the third water pump P 3  is not operated and the third valve V 3  is closed (step S 13 ). 
         [0100]    As described above, the controlling section  230  executes the flow shown in  FIG. 4  repeatedly at intervals, that is, monitors whether the first and second fuel containers  100 A and  100 B are attached, and switches the communication of the third valve V 3  according to the remaining amounts of the fuel  12  in the fuel containers  100 A and  100 B. The controlling section  230  switches the third valve V 3  so that the fuel container ( 100 A or  100 B) in which the fuel  12  is less than the predetermined amount necessary for power generation is applied as a water collecting container. 
         [0101]    When both of the fuel containers  100 A and  100 B run out of the fuel  12 , the error notification of replacing the fuel containers is given and the operation of the power generating system  300  stops. When the fuel container is exchanged with a new fuel container, the power generating system  300  activates, then the above flow is executed. Thus, continuous operation is enabled. 
         [0102]    Next, the operation after the switching operation by the flow path switching section R 5  of the fuel container ( 100 A or  100 B) to collect water is described. 
         [0103]    In the description below, for the convenience of explanation, an example in which both the first fuel container  100 A and the second fuel container  100 B are attached to the power generating system  200  and for example the fuel  12  of the first fuel container  100 A is used, then the remaining amount of the fuel  12  in the first fuel container  100 A becomes less than the predetermined amount necessary for power generation and the fuel  12  is left in the second fuel container  100 B. 
         [0104]    First, when the first fuel pump P 31  is activated, the fuel  12  in the fuel storing section  1 A of the first fuel container  100 A is sent from the fuel discharge tube  11 A through the first valve V 1  and the first flow meter F 1 . The fuel  12  is mixed with the water supplied by the operation of the first-water pump P 1  and the second valve V 2  from the water tank  201  and sent to the vaporizer  211  of the reactor  210 . When the second water pump P 2  is activated, the water in the water tank  201  is sent to the first and second humidifiers  221  and  222  provided in the cathode of the power generating section  220 . When the air pump PA is activated, the outside air is sent to the combustor  213  through the fifth valve V 5 , and to the carbon monoxide remover  214  through the fourth valve V 4 . When the air pump PA is activated, the outside air is sent to the second humidifier  222 . Here, according to the flow data fed back from the flow meters F 1  and F 2 , the controlling section  230  controls the valves V 1  to V 3  so that the flow rate is a predetermined flow rate. 
         [0105]    In the vaporizer  211 , the fuel  12  supplied from the fuel container  100 A and the water supplied from the water tank  201  are mixed and heated to be evaporated (vaporized), and the fuel  12  (methanol) and the water (water vapor) form a mixture gas to be supplied to the reformer  212 . 
         [0106]    In the reformer  212 , the methanol and the water vapor in the mixture gas supplied by the vaporizer  211  react to the catalyst to generate carbon dioxide and hydrogen (see above-mentioned chemical reaction formula (1)). In the reformer  212 , subsequent to the chemical reaction formula (1) carbon monoxide is sequentially generated (see above-mentioned chemical reaction formula (2)). The mixture gas generated in the reformer  212  including carbon monoxide, carbon dioxide, hydrogen, etc. is supplied to the carbon monoxide remover  214 . 
         [0107]    In the carbon monoxide remover  214 , carbon dioxide and hydrogen is generated from the carbon monoxide and the water vapor in the mixture gas supplied from the reformer  212  and the carbon monoxide uniquely chosen from the mixture gas and the oxygen included in the air supplied from the fourth valve V 4  react and generate carbon dioxide (see above-mentioned chemical reaction formula (3)). 
         [0108]    As shown above, carbon dioxide and hydrogen is generated from the fuel  12 , after passing through the vaporizer  211 , the reformer  212 , and the carbon monoxide remover  214  of the reactor  210 . The reformed gas (carbon dioxide, hydrogen, etc.) generated in the reactor  210  is supplied to the first humidifier  221 . The first humidifier  221  is supplied with water supplied from the water tank  201  through the flow path switching section R 3 , the second water pump P 2  and the second humidifier  222 , and after humidifying the reformed gas, supplies the reformed gas to the anode of the power generating section  220 . 
         [0109]    As for the reformed gas supplied to the anode of the power generating section  220 , the hydrogen in the reformed gas separates to hydrogen ion and electron as shown in the above-mentioned chemical reaction formula (4). 
         [0110]    Air is supplied to the second humidifier  222  through the air pump PA. After the second humidifier  222  is supplied with water which is supplied from the water tank  201  through the flow path switching section R 3  and the second water pump P 2 , and the air is humidified by allowing the air to pass through the supplied water, then the air is supplied to the cathode of the power generating section  220 . 
         [0111]    As for the air supplied to the cathode of the power generating section  220 , the oxygen in the air reacts to the hydrogen ion and electron as shown in the above-mentioned chemical reaction formula (5), and water is generated as a by-product. 
         [0112]    The unreacted hydrogen in the anode is sent to the combustor  213  as offgas and combusted, to be used as energy in order to heat reactor  210  when necessary. The water included in the discharged gas obtained by combustion in the combustor  213  is stored in the water tank  201  and the other gases such as carbon dioxide are discharged outside the power generating system  300 . 
         [0113]    In the cathode, the supplied air is discharged with the water, which is the by-product and stored in the water tank  201 . 
         [0114]    Here, when it is detected that the amount of the fuel  12  in the first fuel container  100 A is less than the predetermined amount necessary for power generation, and the amount of water in the water tank  201  is a predetermined amount, which is a threshold, or more, the flow path is switched by the flow path switching section R 5  so that the third valve V 3  is in communication with the fuel container  100 A with less than the predetermined amount, and the third water pump P 3  and the third valve V 3  is activated. At this time, the sum (for example 10 ml) of the amount of water necessary for the vaporizer  211  at starting up and the amount of water necessary for the first humidifier  221  and the second humidifier  222  to humidify at starting up is left in the water tank  201  and the surplus water is sent to the fuel container  100 A by the third water pump P 3 . Therefore, the surplus water is not sent to the second fuel container  100 B in which the fuel  12  is still left, thus an indefinite amount of water and fuel  12  are not mixed so the fuel  12  can be used in the power generating module  200 . The water tank  201  may be set so that the water is sent in order to exceed the necessary amount at starting up and to maintain the predetermined amount, which is the threshold. 
         [0115]    The electric energy generated by the power generating section  220  is charged in the secondary cell  241 . The generated electric energy is supplied to the DC/DC converter  240  and the electric energy is converted to a predetermined voltage of a direct current and is supplied to the external electronic device. The external electronic device operates with the supplied electric energy. 
         [0116]    In the above description, an example in which the fuel  12  of the first fuel container  100 A is used, however the fuel  12  in the second fuel container  100 B may be used, or both fuel containers  100 A and  100 B may be used. In this case, the fuel container ( 100 A or  100 B) in which the amount of the fuel  12  is less than the predetermined amount may be used to collect water and the other operations is the same as the above, thus the explanation will be omitted. 
         [0117]    Next, a case in which the water is reused when the water is collected in the fuel storing section ( 1 A or  1 B) of the fuel container ( 100 A or  100 B) in which the amount of the fuel  12  is less than the predetermined amount necessary for power generation will be described with reference to  FIG. 3 . 
         [0118]    An example in which the water collected in the first fuel container  100 A is reused will be explained. 
         [0119]    First, when the water is collected in the fuel storing section  1 A of the first fuel container  100 A, it is determined according to the remaining amount information from the first remaining amount sensor S 21  that the remaining amount of fuel  12  is less than the predetermined amount necessary for power generation and that there is still remaining water left, and the flow path switching section R 1  switches the flow path from the first fuel pump P 31  to the fuel path switching section R 3  and the fourth water pump P 4 . 
         [0120]    At this time, the fuel  12  is stored in the fuel storing section  1 B of the second fuel container  100 B, thus according to the remaining amount information from the second remaining amount sensor S 22 , the flow path switching section R 2  remains connected to the second fuel pump P 32 , and the flow path is not switched to the flow path switching section R 4  and the fifth water pump P 5 . 
         [0121]    The fuel  12  in the fuel storing section  1 B of the second fuel container  100 B is sent to the vaporizer  211  of the reactor  210  through the fuel discharge tube  11 B, the first valve V 1  and the first flow meter F 1 . The flow path switching section R 1  switches the flow path to the flow path switching section R 3  and the fourth water pump P 4  in order to activate the fourth water pump P 4 , and the collected water in the fuel storing section  1 A of the first fuel container  100 A is sent to the vaporizer  211  of the reactor  210  through the fuel discharge tube  11 A, the sixth valve V 6 , and the third flow meter F 3 . By determining that there is water remaining in the first fuel container  100 A according to the remaining amount information of the first remaining amount sensor S 21 , the flow path switching section R 3  switches the flow path from the water tank  201  to the fuel storing section  1 A and the water collected in the fuel storing section  1 A is preferentially used. With this, the second water pump P 2  is activated and the water collected in the fuel storing section  1 A is sent to the first and second humidifiers  221  and  222  provided in the cathode of the power generating section  220 . Then, the air pump PA is activated and the outside air is sent to the combustor  213  through the fifth valve V 5  and to the carbon monoxide remover  214  through the fourth valve V 4 . According to the flow rate data fed back from the flow meters F 1  and F 3 , the controlling section  230  controls the valves V 1 , V 7 , V 3  and V 4  so as to maintain a predetermined flow rate. 
         [0122]    Then, as described above, the fuel  12  and the water are passed through the vaporizer  211 , the reformer  212  and the carbon monoxide remover  214  of the reactor  210  and reformed. By supplying reformed gas to the anode of the power generating section  220 , and the air to the cathode of the power generating section  220 , electric power is generated and the unreacted hydrogen generated in the anode is sent to the combustor  213  which is used for combustion so that the discharged gas obtained from the combustor  213  is stored in the water tank  201 . In the cathode, the supplied air is discharged with the water, which is the by-product, and stored in the water tank  201 . 
         [0123]    Then, the surplus water according to the remaining water amount information from the remaining water amount sensor S 1  is sent to the fuel container ( 100 A or  100 B) in which the amount of the fuel  12  is less than the predetermined amount necessary for power generation, and the above-described operation is repeated. 
         [0124]    As described above, according to the power generating system  300 , the discharge path is changed by the third valve V 3  so that the discharge is collected in the fuel storing section ( 1 A or  1 B) of the fuel container ( 100 A or  100 B) in which the amount of the fuel  12  is less than the predetermined amount necessary for power generation. Thus the discharge is not collected in the fuel container ( 100 A or  100 B) in which the fuel  12  remains, so the mixing of the fuel  12  and the discharge can be prevented. The fuel container ( 100 A or  100 B) which is not supplying the fuel  12  is not pressurized. Thus, the fuel  12  does not leak out of the fuel container ( 100 A or  100 B) which is not supplying the fuel  12 . 
         [0125]    Before the discharge is collected in the fuel container ( 100 A or  100 B) in which the amount is less than the predetermined amount, after the water is collected in the water tank  201  and before the water exceeds the acceptable amount of the water tank  201 , the surplus water can be collected in the fuel container ( 100 A or  100 B) in which the amount is less than the predetermined amount, thus the water in the water tank  201  does not exceed the acceptable amount and is not damaged. The discharge is collected in the water tank  201  so the discharge may be reused, which is economical. The fuel container in which the surplus water is collected may be removed and disposed. 
         [0126]    A case in which the power generating system  300  is applied to the electronic device  400  is described. Specifically, the electronic device is a portable electronic device, and the system is applied to a PDA. FIG.  5 A is a top view of an electronic device  400 ,  FIG. 5B  is a bottom view of the electronic device  400  of  FIG. 5A , and  FIG. 5C  is a rear view of the electronic device  400  of  FIG. 5A . 
         [0127]    The electronic device  400  comprises a main body  401  embedded with a processing circuit including a CPU, a RAM, a ROM and other electronic parts, a first fuel container  100 A and a second fuel container  100 B to store fuel  12  which is removably attached to the main body  401 , and a power generating module (not shown) which is provided in the main body  401  and which uses the fuel  12  in the first and second fuel containers  100 A and  100 B in order to generate power, and the generated electric energy is supplied to the main body  401  in order to drive the main body  401 . The structure and the operation of the first and second fuel containers  100 A and  100 B and the power generating module (not shown) are the same as those described above, thus the description is omitted. 
         [0128]    The main body  401  comprises operation keys  402  and a liquid crystal display  403 , and a first storing space  404  and a second storing space  405  are formed in a rectangular shape which stretch in a horizontal direction on the bottom side of the main body  401  so as to be symmetric with respect to a central line in a horizontal direction and are open toward the bottom side and the rear side. The first fuel container  100 A and the second fuel container  100 B may be stored in the first and second storing spaces  404  and  405  from the rear side opening of the main body  401 . Rails  406 ,  406 ,  407 , and  407  are formed on the walls in the longitudinal direction which form the first and second storing spaces  404  and  405  and the rails, engage to the guides  44 A,  44 A,  44 B, and  44 B formed on the fuel containers  100 A and  100 B. The first fuel container  100 A and the second fuel container  100 B are attached to the storing spaces  404  and  405  by sliding the fuel containers  100 A and  100 B from the end section of the discharge opening and supply opening so that the gas-liquid separation film  2 A and  2 B face outward, and engaging the guide section  44 A,  44 A,  44 B, and  44 B to the rail section  406 ,  406 ,  407 , and  407 , respectively. 
         [0129]    As described above, the fuel containers  100 A and  100 B stored in the storing spaces  404  and  405  respectively are attached so that the bottom side is exposed to the outside, thus the bottom side is in direct contact with the outside air so the heat is dissipated well, and the heat is not trapped in the power generating system  300 , which raises the water collection rate. 
         [0130]    As for the present invention, the number of times the cartridge is changed is less than in a structure in which the fuel cartridge and the cartridge for collecting water is different as mentioned in the Japanese Patent Application Laid-open No. 2004-192171, etc. For example, when the fuel cartridge is empty and the cartridge for collecting water is full, in a structure mentioned in Japanese Patent Application Laid-open No. 2004-192171, etc., both cartridges need to be changed, however in the present invention, in a similar situation, only the cartridge for collecting water needs to be changed to a new fuel cartridge. 
         [0131]    In the above embodiment, the power generating module  200  stores two fuel containers and when one fuel container is out of fuel, the by-product is collected in the fuel container, but the structure is not limited to this, and the power generating module  200  may store only one fuel container and after the fuel container runs out of fuel, the by-product may be collected in the fuel container. By alternately changing the fuel containers  100 A and  100 B which has run out of fuel, not only can the electronic device operate continuously, but also the by-product can be easily collected. 
       [Modification] 
       [0132]    Next, a modification of the fuel container will be described. 
         [0133]      FIG. 6  is an exploded perspective view of a fuel container  500 ,  FIG. 7A  is a top view of the fuel container  500 , and  FIG. 7B  is a sectional view taken along cross-section line VII-VII. 
         [0134]    The fuel container  500  is different from the fuel container  100  of the first embodiment. Openings  543   a  and  543   b  formed on the case  504 , a gas-liquid separation film  502  which is attached to the openings  543   a  and  543   b  and includes a hydrophobic porous membrane, and a guide section  544  are different. The fuel storing section  501  is the same as the above described fuel storing section  1 , the fuel discharge opening  511  is the same as the fuel discharge opening  11 , the discharge collecting opening  541  is the same as the discharge collecting opening  41 , the discharge sending tube  542  is the same as the discharge sending tube  42 , thus detailed descriptions are omitted. 
         [0135]    The fuel container  500  includes a fuel storing section  501  to store fuel  12 . The fuel storing section  501  cools and collects discharge including gas and water discharged from a power generating module (not shown) which generates power with the fuel  12  supplied from the fuel storing section  501 . 
         [0136]    On a right end surface  504 A of the case  504 , a fuel discharge opening  511 , which discharges the fuel  12  to the power generating module is formed in a convex shape projecting outward from the right end surface  504 A by penetrating the end surface  540 A so as to be in communication with the inside of the fuel storing section  501 . On the right end surface  504 A of the case  504 , at the upper side of the fuel discharge opening  511 , a discharge collecting opening  541  is formed. A fuel discharge opening (not shown) is provided in the fuel discharge opening  511  and a discharge supplying opening (not shown) is provided in the discharge collecting opening  541 . As described above, a check valve (not shown) is fitted in the fuel discharge opening and the discharge supplying opening. A discharge sending tube  542  is connected to the discharge collecting opening  541 , and is laid on the lower side from the discharge collecting opening  541  and extends toward the left end surface of the fuel storage section  501  along the longitudinal direction. 
         [0137]    On the upper surface  504 C in the side of the opposite end surface  504 B in the longitudinal direction of the case  504  (left end surface in  FIG. 6 ), a rectangular opening  543   a  which communicates to the inside of the case  504  is formed, and on the left end surface  504 B a rectangular opening  543 B which communicates to the inside of case  4  is formed. A gas-liquid separation film  502  is folded so as to straddle the two openings  543   a  and  543   b  and to cover these openings  543   a  and  543   b . Thus, gas may pass between inside and outside of the case  504  through the gas-liquid separation film  502  but water may not pass through the gas-liquid separation film  502 . Therefore, the water does not leak outside. The gas-liquid separation film  502  is attached so as to straddle the two openings  543   a  and  543   b , thus air may be discharged from two places, the openings  543   a  and  543   b.    
         [0138]    A guide  544  is attached to a bottom surface  504 D at the left end side of the case  504  for removably attaching the case  504  to a later-described electronic device  800 . The guide  544  projects downward from the bottom surface  504 D of the case  504  and is T-shaped from a side sectional view (See  FIG. 6 ). 
         [0139]    The fuel  12  inside the fuel storing section  501  in the above-described fuel container  500  is supplied to the power generating module through the fuel discharge opening  511  and the fuel  12  is used to generate electric energy. The discharge produced from the power generating module is supplied into the discharge sending tube  542  through the discharge collecting opening  541 , then flows through the discharge sending tube  542  to be sent to the fuel storing section  501 . The gas in the discharge is cooled while flowing in the discharge sending tube  542 , and a portion is condensed to water to be collected in the fuel storing section  501 . The gas which was not condensed is released outside through the gas-liquid separation film  502  and the water cannot pass through the gas-liquid separation film  502  and is accumulated in the fuel storing section  501 . The cooling of the discharge is also promoted by the water collected in the fuel storing section  501  and condensed. 
         [0140]    In a power generating system comprising a plurality of the above described fuel containers  500  and a power generating module, the structure and the operation is the same as the above-described power generating system  300 , thus, the explanation is omitted. 
         [0141]    Next, a case in which a power generating system comprising a first fuel container  500 A and a second fuel container  500 B which have the same structure as the fuel container  500  and a power generating module is applied to a electronic device  800  is explained. Specifically, the electronic device is a portable device and the system is applied to a laptop personal computer. In the description below, the components of the first fuel container  500 A correspond to the components of the above-described fuel container  500 , thus an alphabet A will be applied to the same reference numbers, and as for the second fuel container  500 B, an alphabet B will be applied to the same reference numbers. 
         [0142]      FIG. 8A  is a top view of the electronic device  800 ,  FIG. 8B  is a right side view of the electronic device  800  of  FIG. 8A , and  FIG. 8C  is a rear view of the electronic device  800  of  FIG. 8A . 
         [0143]    The electronic device  800  comprises a main body  801  embedded with a processing circuit including a CPU, a RAM, a ROM and other electronic parts, a first fuel container  500 A and a second fuel container  500 B to store fuel  12  which are removably attached to the main body  801 , and a power generating module (not shown) which is provided in the main body  801  and which uses the fuel  12  in the first and second fuel containers  500 A and  500 B in order to generate power, and the generated electric energy is supplied to the main body  801  in order to drive the main body  801 . The structure and the operation of the first and second fuel containers  500 A and  500 B and the power generating module (not shown) are the same as those described above, thus the description is omitted. 
         [0144]    The main body  801  comprises a lower case  802  equipped with a keyboard and an upper case  803  equipped with a liquid crystal display. The upper case  803  is connected to the lower case  802  with a hinge  807 . The main body  801  is structured so that it can be folded in a state in which the upper case  803  is laid on the lower case  802  and the liquid crystal display is facing the keyboard. The length from the rear side to the front side of the upper case  803  is shorter than that of the lower case  802  and the main body  801  may be folded so that the end of the upper case  803  is aligned with the end of the case  802  at the front end. Thus, when the upper case  803  is laid on the lower case  802 , a portion of an upper surface of the lower case  802  on the rear side is not covered with the upper case  803  and is exposed. 
         [0145]    In the exposed areas of the lower case  802 , a rectangular first storing space  804 , which is open toward the upper surface, the left side surface, and the rear surface and stretches in a horizontal direction, and a rectangular second storing space  805 , which is open toward the upper surface, the right side surface, and the rear surface and stretches in a horizontal direction, are formed so as to be symmetric with respect to a central line in a horizontal direction. 
         [0146]    The first fuel container  500 A may be stored in the first storing space  804  from the left side opening. A rail (not shown) is formed on the left end of the bottom section of the first storing space  804 , and the rail engages to a guide (not shown) which is formed on the bottom surface of the first fuel container  500 A. 
         [0147]    The second fuel container  500 B may be stored in the second storing space  805  from the right side opening. A rail  806  is formed on the right end of the bottom section of the second storing space  805 , and the rail  806  engages to a guide  544 B of the second fuel container  500 B. 
         [0148]    The first fuel container  500 A and the second fuel container  500 B are attached to the storing spaces  804  and  80  respectively by sliding the fuel containers  500 A and  500 B from the end section of the discharge opening and supply opening so that the ends of the gas-liquid separation film  502 A and  502 B face outward, and engaging the guide  544 B to the rail  806 . 
         [0149]    As described above, the fuel containers  500 A and  500 B stored in the storing spaces  804  and  805  respectively are attached so that the bottom side is exposed to the outside, thus the bottom side is in direct contact with the outside air so the heat is dissipated well, and the heat is not trapped in the power generating system, which raises the water collection rate. 
         [0150]    The present invention is not limited to the above-described embodiments, and the invention can be appropriately modified within a range not departing from its subject matter. 
         [0151]    For example, in the above-described embodiment, the power generating system  300  comprises two fuel containers, a first fuel container  100 A and  500 A and a second fuel container  100 B and  500 B, however the system may comprise three or more containers. 
         [0152]    The shape, etc. of the components in the fuel container  100  and  500  may be appropriately modified. For example, the openings  43 ,  543   a  and  543   b  are rectangular, however the openings may be formed with multiple holes. 
         [0153]    In the above-described embodiments, a reactor  210  is provided so that the fuel  12  is reformed and then supplied to the power generating section, which is a fuel cell. However, the power generating module may be a direct-type fuel cell in which the reactor is not provided and the fuel  12  from the first and second fuel containers  100  and  500  may be directly supplied to the fuel cell. 
         [0154]    The entire disclosure of Japanese Patent Application No. 2006-304801 on Nov. 10, 2006 including specification, claims, drawings and abstract are incorporated herein by reference in its entirety. 
         [0155]    Although various exemplary embodiments have been shown and described, the invention is not limited to the embodiments shown. Therefore, the scope of the invention is intended to be limited solely by the scope of the claims that follow.