Abstract:
A heat exchanger ( 20 ) is provided with: two header pipes ( 21, 22 ) which are disposed parallel to each other with a space therebetween; a plurality of flat tubes ( 23 ) which are disposed between the header pipes, refrigerant passages ( 24 ) provided therein communicating with the interiors of the header pipes; and fins ( 25 ) which are disposed between the flat tubes. The plurality of flat tubes are divided into two parts: an upper group ( 27 ) located in the upper part; and a lower group ( 28 ) located in the lower part. The flat tubes of the upper group and parts corresponding thereto of the header pipes constitute an upper heat exchange part ( 40 ), and the flat tubes of the lower group and parts corresponding thereto of the header pipes constitute a lower heat exchange part ( 41 ).

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to a side-flow type parallel-flow heat exchanger and an all-in-one air conditioner equipped therewith. 
       BACKGROUND ART 
       [0002]    Widely used in car air conditioners, outdoor units of building air conditioners, etc. are parallel-flow-type heat exchangers in each of which a plurality of flat tubes are disposed between a plurality of header pipes having a plurality of refrigerant passages formed inside the flat tubes to communicate with insides of the header pipes, and in which fins such as corrugated fins are disposed between the flat tubes. 
         [0003]    An example of a conventional side-flow type parallel-flow heat exchanger is shown in  FIG. 6 . A heat exchanger  1  includes two header pipes  2  and  3 , and a plurality of flat tubes  4  disposed between the header pipes  2  and  3 . In  FIG. 6 , the header pipes  2  and  3  extend in a vertical direction, and they are arranged parallel to and spaced from each other in a horizontal direction, and the flat tubes  4  extend in the horizontal direction and disposed at a predetermined pitch in the vertical direction. In many cases, however, when it is practically installed in apparatuses, the parallel-flow heat exchanger  1  is set at various angles depending on designs of the apparatuses, and in such cases, needless to say, the terms “horizontal” and “vertical” should not be taken in their strict senses. 
         [0004]    The flat tubes  4  are elongate members made by extrusion of metal and have a refrigerant passage  5  formed inside thereof for a refrigerant to flow therethrough. The flat tubes  4  are disposed such that the extrusion direction, which is the longitudinal direction of the flat tubes  4 , is horizontal, and thus the direction in which the refrigerant flows through the refrigerant passages  5  is also horizontal. As the refrigerant passage  5 , a plurality of refrigerant passages  5  having the same sectional shape and area are arranged in the depth direction in  FIG. 4 , so that the vertical section of each of the flat tubes  4  has a harmonica-like shape. The refrigerant passages  5  each communicate with the inside of the header pipes  2  and  3 . A fin  6  is disposed between each adjacent two of the flat tubes  4 . Although a corrugated fin is used as the fin  6 , a plate fin may be used instead. 
         [0005]    The header pipes  2  and  3 , the flat tubes  4 , and the fins  6  are made of a highly heat conductive material such as aluminum. The flat tubes  4  are fixed by brazing or welding to the header pipes  2  and  3 , and so are the corrugated fins  6  to the flat tubes  4 . 
         [0006]    In the heat exchanger  1  shown in  FIG. 6 , refrigerant ports  7  and  8  are provided in the header pipe  3  alone. Inside the header pipe  3 , partition panels  9   a  and  9   c  are provided to be spaced from each other in a vertical direction; inside the header pipe  2 , a partition panel  9   b  is provided at a height between the partition panels  9   a  and  9   c.    
         [0007]    When the heat exchanger  1  is used as an evaporator, a refrigerant flows in through the lower refrigerant port  7  as indicated by a solid-line arrow in  FIG. 6 . The refrigerant that has entered through the refrigerant port  7  is blocked by the partition panel  9   a  and flows toward the header pipe  2  via some of the flat tubes  4 . This flow of the refrigerant is indicated by a left-pointing block arrow. The refrigerant that has entered the header pipe  2  is then blocked by the partition panel  9   b  and flows toward the header pipe  3  via other flat tubes  4 . This flow of the refrigerant is indicated by a right-pointing block arrow. The refrigerant that has entered the header pipe  3  is then blocked by the partition panel  9   c  and flows toward the header pipe  2  again via still other flat tubes  4 . This flow of the refrigerant is indicated by another left-pointing block arrow. The refrigerant that has entered the header pipe  2  flows back toward the header pipe  3  again via still other flat tubes  4 . This flow of the refrigerant is indicated by another right-pointing block arrow. The refrigerant that has entered the header pipe  3  then flows out through the refrigerant port  8 . In this way, the refrigerant flows from down upward along a zigzag route. Although the number of partition panels is three here, it is merely one example, and the number of partition panels and the resulting number of times the refrigerant flows back can be set arbitrarily as required. 
         [0008]    When the heat exchanger  1  is used as a condenser, the refrigerant flows in an opposite direction. Specifically, the refrigerant flows into the header pipe  3  through the refrigerant port  8  as indicated by a dotted-line arrow in  FIG. 6 , is then blocked by the partition panel  9   c  and flows toward the header pipe  2  via some flat tubes  4 , is then blocked by the partition panel  9   b  in the header pipe  2  and flows toward the header pipe  3  via other flat tubes  4 , is then blocked by the partition panel  9   a  in the header pipe  3  and flows toward the header pipe  2  again via still other flat tubes  4 , then flows back at the header pipe  2  toward the header pipe  3  again via still other flat tubes  4 , and then flows out through the refrigerant port  7 , as indicated by a dotted-line arrow; that is, the refrigerant flows from up downward along a zigzag route. 
         [0009]    The above description deals with a case where the refrigerant is made to flow from down upward when the heat exchanger  1  is used as the evaporator while the refrigerant is made to flow from up downward when the heat exchanger  1  is used as the condenser; however, a setting is possible where the refrigerant is oppositely directed. 
         [0010]    A typical example of an apparatus equipped with a heat exchanger is an air conditioner, one example of which is an all-in-one air conditioner. It is used where a separate-type conditioner composed of outdoor and indoor units cannot be placed, and composed of a condenser and an evaporator disposed in one housing to be placed inside a room such that heat is discharged to outside the room via an air discharge duct and meanwhile air is circulated inside the room to thereby adjust the room temperature. Examples of such an all-in-one air conditioner are disclosed in Patent Literatures 1 and 2 listed below. 
         [0011]    An all-in-one air conditioner disclosed in Patent Literature 1 includes an evaporator and a condenser both built as a fin-and-tube type heat exchanger where a copper tube penetrates a large number of aluminum fins. The evaporator and the condenser are independent components and placed away from each other. During a cooling operation, heat is discharged from the condenser via an air discharge duct; one end of the air discharge duct is connected to a lower outlet port provided in a backside of the air conditioner and another end of the air discharge duct is connected to, for example, a window. 
         [0012]    An all-in-one air conditioner disclosed in Patent Literature 2 includes a housing separated by a partition panel into upper and lower parts, which are a cooling chamber and a heat discharging chamber, respectively; an evaporator is disposed in the cooling chamber while a condenser is disposed in the heat discharging chamber. The heat discharging chamber is provided with an air intake port and an air outlet port, and one end of an air discharge duct is attached to the air outlet port while one end of an air intake duct is detachably attached to the air intake port. The other end of the air discharge duct is attached to an opening such as a window. The other end of the air intake duct is, like that of the air discharge duct, able to be attached to an opening such as a window to achieve air intake/discharge by a double-duct method where both the air discharge duct and the air intake duct are used. 
         [0013]      FIG. 7  shows an all-in-one air conditioner of the type described in Patent Literature 2. The air conditioner  10  includes a housing  11  which is separated by a horizontal partition panel  12  into upper and lower parts, namely a cooling chamber  13  and a heat discharging chamber  14 , respectively. In the cooling chamber  13 , an evaporator  15  is disposed, and in the heat discharging chamber  14 , a condenser  16  and a compressor  17  are disposed. The evaporator  15 , the condenser  16 , and the compressor  17 , together with an unillustrated pressure reducing expansion unit and an unillustrated four-way valve, form a heat pump cycle as a refrigerating cycle. Besides, an unillustrated blower is provided in the cooling chamber  13 , to form a room-air-circulation air path  18  which is indicated by a broken-line arrow. Another unillustrated blower is provided in the heat discharging chamber  14 , to form a heat-discharging air path  19  which is indicated by a broken-line arrow. The heat-discharging air path  19  is formed to send air that passes through the condenser  16  into an unillustrated air discharge duct. The evaporator  15  and the condenser  16  are each a fin-and-tube type heat exchanger. 
       CITATION LIST 
     Patent Literature 
       [0000]    
       
         Patent Literature 1: JP-A-2005-274077 
         Patent Literature 2: JP-A-2010-54111 
       
     
       SUMMARY OF INVENTION 
     Technical Problem 
       [0016]    The all-in-one air conditioners described in Patent Literatures 1 and 2 both include separate heat exchangers respectively used as the evaporator and the condenser, which invites complexity in configuration, preventing achievement of a compact and lightweight all-in-one air conditioner. 
         [0017]    The present invention has been made in view of the foregoing, and an object of the present invention is to provide a side-flow type parallel-flow heat exchanger suitable for all-in-one air conditioners, and an all-in-one air conditioner equipped therewith. 
       Solution to Problem 
       [0018]    A side-flow type parallel-flow heat exchanger according to the present invention includes a plurality of header pipes disposed in parallel at intervals, a plurality of flat tubes disposed between the plurality of header pipes, the flat tubes each having a refrigerant passage formed therein to communicate with insides of the header pipes, and a fin disposed between adjacent ones of the plurality of flat tubes. Here, the plurality of flat tubes are divided into an upper group located in an upper part of the heat exchanger and a lower group located in a lower part of the heat exchanger, a flat tube belonging to the upper group and part of the plurality of header pipes corresponding to the flat tube belonging to the upper group form an upper heat exchanging portion, and a flat tube belonging to the lower group and part of the plurality of header pipes corresponding to the flat tube belonging to the lower group form a lower heat exchanging portion. 
         [0019]    In the heat exchanger having the above configuration, it is preferable that one of the upper heat exchanging portion and the lower heat exchanging portion function as an evaporator, and that the other one of the upper heat exchanging portion and the lower heat exchanging portion function as a condenser. 
         [0020]    In the heat exchanger having the above configuration, it is preferable that, in one of the upper heat exchanging portion and the lower heat exchanging portion that functions as the condenser, a refrigerant flow through the flat tubes from an upper one of the flat tubes to a lower one of the flat tubes. 
         [0021]    In the heat exchanger having the above configuration, it is preferable that a heat insulating portion be provided between the upper heat exchanging portion and the lower heat exchanging portion. 
         [0022]    In the heat exchanger having the above configuration, it is preferable that a heat-insulating partition panel be provided inside the plurality of header pipes, and that the heat-insulating partition panel function as part of the heat insulating portion. 
         [0023]    An all-in-one air conditioner according to the present invention includes any one of the above-described heat exchangers, and a housing including a room-air-circulation air path and a heat-discharging air path. Here, the upper heat exchanging portion of the heat exchanger is disposed in the room-air-circulation air path, and the lower heat exchanging portion of the heat exchanger is disposed in the heat-discharging air path. 
         [0024]    In the air conditioner having the above configuration, it is preferable that the upper heat exchanging portion function as an evaporator, and that the lower heat exchanging portion function as a condenser. 
       Advantageous Effects of Invention 
       [0025]    According to the present invention, flat tubes disposed between header pipes are divided into an upper group and a lower group, flat tubes of the upper group and part of the plurality of header pipes corresponding to the flat tubes of the upper group form an upper heat exchanging portion, and flat tubes of the lower group and part of the plurality of header pipes corresponding to the flat tubes belonging to the lower group form a lower heat exchanging portion. This configuration makes it possible to achieve a compact and lightweight side-flow type parallel-flow heat exchanger where an evaporator and a condenser are combined. This accordingly makes it possible to achieve a compact and lightweight all-on-one air conditioner equipped with such a heat exchanger. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0026]      FIG. 1  is a vertical sectional view showing a schematic structure of a side-flow type parallel-flow heat exchanger according to a first embodiment of the present invention; 
           [0027]      FIG. 2  is a side view showing a schematic configuration of an all-in-one air conditioner equipped with a heat exchanger according to the present invention; 
           [0028]      FIG. 3  is a vertical sectional view showing a schematic structure of a side-flow type parallel-flow heat exchanger according to a second embodiment of the present invention; 
           [0029]      FIG. 4  is a vertical sectional view showing a schematic structure of a side-flow type parallel-flow heat exchanger according to a third embodiment of the present invention; 
           [0030]      FIG. 5  is a vertical sectional view showing a schematic structure of a side-flow type parallel-flow heat exchanger according to a fourth embodiment of the present invention; 
           [0031]      FIG. 6  is a vertical sectional view showing a schematic structure of a conventional side-flow type parallel-flow heat exchanger; and 
           [0032]      FIG. 7  is a side view showing a schematic configuration of a conventional all-in-one air conditioner. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0033]    Descriptions will be given below of a side-flow type parallel-flow heat exchanger according to a first embodiment of the present invention, with reference to  FIG. 1 . 
         [0034]    A structure of a parallel-flow heat exchanger  20  is basically the same as the conventional structure shown in  FIG. 6 . Specifically, a plurality of flat tubes  23  extending in a horizontal direction are disposed between two vertically-extending header pipes  21  and  22 . Here, the terms “horizontal” and “vertical” are used in the same senses as in the above-given descriptions of the conventional structure. 
         [0035]    The flat tubes  23 , refrigerant passages  24  inside the flat tubes  23 , and fins  25  have the same configurations and fixed in the same manner as the flat tubes  4 , the refrigerant passages  5 , and the fins  5 , respectively, of the conventional structure. A combination of a fin  25  and a side plate  26  is disposed on an external flat surface of an outermost one of the plurality of flat tubes  23  placed in a vertical row. 
         [0036]    The plurality of flat tubes  23  are divided into an upper group  27  disposed in an upper part and a lower group  28  disposed in a lower part. A space  29  is provided between the upper group  27  and the lower group  28 . The space  29  functions as a heat insulating portion HI that prevents thermal influence of one on the other of the upper group  27  and the lower group  28 . Partition panels  30  and  31  are provided inside the header pipes  21  and  22 , respectively, at positions between the upper and lower groups  27  and  28 . Thereby, the upper and lower groups  27  and  28  are completely separated from each other. 
         [0037]    Part of the header pipes  21  and  22  located above the partition panels  30  and  31  and the flat tubes  23  belonging to the upper group  27  form an upper heat exchanging portion  40 . Part of the header pipes  21  and  22  located below the partition panels  30  and  31  and the flat tubes  23  belonging to the lower group  27  form a lower heat exchanging portion  41 . 
         [0038]    In the upper heat exchanging portion  40 , an upper refrigerant port  32  and a lower refrigerant port  33  are formed in the header pipe  22 . Inside the header pipe  22 , a partition panel  34  is provided at a height between the upper and lower refrigerant ports  32  and  33 . 
         [0039]    In the upper heat exchanging portion  40 , a number of the flat tubes  23  located above the partition panel  34  and a number of the flat tubes  23  located below the partition panel  34  are set to be equal. However, in some cases, in view of pressure loss caused by evaporation, a flow path located on a latter stage in a cooling operation may be designed to include a larger number of flat tubes  2 . 
         [0040]    In the lower heat exchanging portion  41 , an upper refrigerant port  35  and a lower refrigerant port  36  are formed in the header pipe  22 . Inside the header pipe  22 , partition panels  37  and  38  are provided at positions between the upper and lower refrigerant ports  35  and  36 . Inside the header pipe  21 , a partition panel  39  is provided at a height between the partition panels  37  and  38 . 
         [0041]    In the lower heat exchanging portion  41 , a number of the flat tubes  23  disposed below the partition panel  38  is equal to a number of the flat tubes  23  disposed between heights of the partition panels  38  and  39 , a number of the flat tubes  23  disposed between heights of the partition panels  39  and  37  is smaller than the number of the flat tubes  23  disposed below the partition panel  38  or between the heights of the partition panels  38  and  39 , and further, a number of the flat tubes  23  disposed above the partition panel  37  is smaller than the number of the flat tubes  23  disposed between the heights of the partition panels  39  and  37 . 
         [0042]    The lower refrigerant port  33  of the upper heat exchanging portion  40  and the upper refrigerant port  35  of the lower heat exchanging portion  41  are connected to each other via a refrigerant pipe  42 . The refrigerant pipe  42  is provided with a pressure reducing expansion unit  43 . 
         [0043]    During a cooling operation, the upper heat exchanging portion  40  is made to function as an evaporator, and the lower heat exchanging portion  41  is made to function as a condenser. That is, a high-temperature high-pressure refrigerant discharged from an unillustrated compressor flows through the lower refrigerant port  36  into the lower heat exchanging portion  41 . The refrigerant which has entered the lower heat exchanging portion  41  flows in the flat tubes  23  located below the partition panel  38  toward the header pipe  21 . The refrigerant that has entered the header pipe  21  then flows in the flat tubes  23  located between the partition panels  38  and  39  back toward the header pipe  22 . The refrigerant that has entered the header pipe  22  then flows in the flat tubes  23  located between the partition panels  39  and  37  back toward the header pipe  21  again. The refrigerant that has entered the header pipe  21  then flows in the flat tubes  23  located above the partition panel  37  back toward the header pipe  22  again, and then flows out through the upper refrigerant port  35 . 
         [0044]    The high-temperature high-pressure refrigerant that has entered through the lower refrigerant port  36  into the lower heat exchanging portion  41 , while flowing zigzag from down upward inside the lower heat exchanging portion  41 , dissipates heat to air passing through the lower heat exchanging portion  41 , and the refrigerant condenses. The refrigerant that has flown out of the upper refrigerant port  35  of the lower heat exchanging portion  41  flows via the pressure reducing expansion unit  43  and then through the lower refrigerant port  33  into the upper heat exchanging portion  40 . 
         [0045]    The refrigerant which has entered the upper heat exchanging portion  40  through the lower refrigerant port  33  flows through the flat tubes  23  located below the partition panel  34  toward the header pipe  21 . The refrigerant that has entered the header pipe  21  then flows back through the flat tubes  23  located above the partition panel  34  toward the header pipe  22 . The refrigerant that has entered the header pipe  22  flows out through the upper refrigerant port  32 . In this way, the refrigerant expands while flowing zigzag inside the upper heat exchanging portion  40 , the refrigerant taking heat from air passing through the upper heat exchanging portion  40 . Then, the refrigerant flows out through the upper refrigerant port  32  back to the unillustrated compressor. In this way, in the upper heat exchanging portion  40  functioning as the evaporator, the refrigerant flows from the lower flat tubes  23  to the upper flat tubes  23 . Instead, in the upper heat exchanging portion  40  functioning as the evaporator, the refrigerant may flow from the upper flat tubes  23  to the lower flat tubes  23 . 
         [0046]    The provision of the heat insulating portion HI between the upper heat exchanging portion  40  and the lower heat exchanging portion  41  helps reduce thermal influence of one of the upper heat exchanging portion  40  and the lower heat exchanging portion  41  on the other. This allows the upper heat exchanging portion  40  to fully function as the evaporator, and the lower heat exchanging portion  41  to fully function as the condenser. 
         [0047]    During a heating operation, an unillustrated four-way valve is switched to reverse the direction in which the refrigerant flows. That is, the high-temperature high-pressure refrigerant discharged from the unillustrated compressor enters the upper heat exchanging portion  40  through the upper refrigerant port  32 , and there, the refrigerant dissipates heat to air passing through the upper heat exchanging portion  40 , and the refrigerant condenses. The refrigerant that has flown through the lower refrigerant port  33  out of the upper heat exchanging portion  40  flows via the pressure reducing expansion unit  43  and through the upper refrigerant port  35  into the lower heat exchanging portion  41 . The refrigerant expands in the lower heat exchanging portion  41 , absorbing heat from air passing through the lower heat exchanging portion  41 , and then flows through the lower refrigerant port  36  back to the unillustrated compressor. 
         [0048]    The side-flow type parallel-flow heat exchanger  20  is configured such that the header pipes  21  and  22  are shared by the upper heat exchanging portion  40  and the lower heat exchanging portion  41 , one of the two portions is used as the evaporator and the other as the condenser. This configuration is compact compared with a configuration where separate side-flow type parallel flow heat exchangers are provided such that one is used exclusively as an evaporator and the other as a condenser. 
         [0049]      FIG. 2  shows a case where the parallel-flow heat exchanger  20  is equipped in an all-in-one air conditioner. The all-in-one air conditioner  10  shown in  FIG. 2  basically follows the structure of the all-in-one air conditioner shown in  FIG. 7 . Such components as find their counterparts in  FIG. 7  are identified with common reference signs, and no description of them will be repeated. 
         [0050]    In the parallel-flow heat exchanger  20  fitted inside a housing  11 , the upper heat exchanging portion  40  is disposed in an room-air-circulation air path  18  and the lower heat exchanging portion  41  is disposed in a heat-discharging air path  19 . 
         [0051]    Being equipped with the parallel-flow heat exchanger  20  having a compact configuration, the all-in-one air conditioner  10  itself can also be compact and lightweight. Furthermore, in comparison with a case where an evaporator and a condenser are separately installed, installation can be achieved by an easier operation in a shorter period of time. 
         [0052]    In the cooling operation, moisture contained in the air condenses into condensate on an external surface of the upper heat exchanging portion  40  functioning as the evaporator. The condensate is caused to drop or flow down by gravity, to wet the lower heat exchanging portion  41  functioning as the condenser. This further enhances the condensation effect of the lower heat exchanging portion  41 . 
         [0053]    A parallel-flow heat exchanger  20  according to a second embodiment is shown in  FIG. 3 . The second embodiment is different from the first embodiment in that the partition panels  30  and  31  inside the header pipes  21  and  22  of the first embodiment are replaced with heat-insulating partition panels  30 HI and  31 HI, respectively. The heat-insulating partition panels  30 HI and  31 HI take part in forming a heat insulating portion HI, achieving further secure thermal separation. 
         [0054]    In  FIG. 3 , the heat-insulating partition panels  30 HI and  31 HI are each formed of two partition panels that are disposed spaced from each other. The heat-insulating partition panels  30 HI and  31 HI are made of aluminum, and thus, if they were each formed of a single panel, heat transfer would be likely to occur; however, by forming them of two panels arranged spaced from each other, it is possible to give them sufficient heat insulating properties. Some gas may be sealed in the space between the two panels, or the space may be a vacuum space. 
         [0055]    The heat-insulating partition panels  30 HI and  31 HI may be formed by a method other than the above method. For example, the heat-insulating partition panels  30 HI and  31 HI may each be formed of a thicker panel or of a panel made of a heat insulating material. 
         [0056]    A parallel-flow heat exchanger  20  according to a third embodiment is shown in  FIG. 4 . In the third embodiment, a lower refrigerant port  36  of a lower heat exchanging portion  41  is connected to a lower refrigerant port  33  of an upper heat exchanging portion  40  via a refrigerant pipe  42 . 
         [0057]    In the parallel-flow heat exchanger  20  according to the third embodiment, in the lower heat exchanging portion  41 , a number of flat tubes  23  disposed above a partition panel  37  is equal to a number of flat tubes  23  disposed between heights of the partition panel  37  and a partition panel  39 , and a number of flat tubes  23  disposed between heights of the partition panel  39  and a partition panel  38  is smaller than the number of the flat tubes  23  disposed above the partition panel  37  or between the heights of the partition panels  37  and  39 , and a number of flat tubes  23  disposed below the partition panel  38  is smaller than the number of the flat tubes  23  disposed between the heights of the partition panels  39  and  38 . 
         [0058]    During a cooling operation, a high-temperature high-pressure refrigerant discharged from an unillustrated compressor enters the lower heat exchanging portion  41  through an upper refrigerant port  35 . The refrigerant which has entered the lower heat exchanging portion  41  flows in the flat tubes  23  located above the partition panel  37  toward the header pipe  21 . The refrigerant that has entered the header pipe  21  then flows in the flat tubes  23  located between the partition panels  37  and  39  back toward the header pipe  22 . The refrigerant that has entered the header pipe  22  then flows in the flat tubes  23  located between the partition panels  39  and  38  back toward the header pipe  21  again. The refrigerant that has entered the header pipe  21  then flows in the flat tubes  23  located below the partition panel  38  back toward the header pipe  22  again, and then flows out through the lower refrigerant port  36 . 
         [0059]    The high-temperature high-pressure refrigerant that has entered through the upper refrigerant port  35  into the lower heat exchanging portion  41 , while flowing zigzag from up downward inside the lower heat exchanging portion  41 , dissipates heat to air passing through the lower heat exchanging portion  41 , and the refrigerant condenses. The refrigerant that has flown out of the lower refrigerant port  36  of the lower heat exchanging portion  41  flows via the pressure reducing expansion unit  43  and through the lower refrigerant port  33  into the upper heat exchanging portion  40 . The refrigerant expands in the upper heat exchanging portion  40 , taking heat from air passing through the upper heat exchanging portion  40 . Then, the refrigerant flows out through an upper refrigerant port  32  back to the unillustrated compressor. 
         [0060]    In the lower heat exchanging portion  41  functioning as a condenser, the refrigerant flows from an upper flat tube  23  to a lower flat tube  23 . Movement from up downward is natural for the refrigerant, which is a liquid, and thus, this embodiment allows efficient heat exchange to be achieved. 
         [0061]    A parallel-flow heat exchanger  20  according to a fourth embodiment is shown in  FIG. 5 . In the fourth embodiment, a lower refrigerant port  36  of a lower heat exchanging portion  41  is connected to an upper refrigerant port  32  of an upper heat exchanging portion  40  via a refrigerant pipe  42 . 
         [0062]    During a cooling operation, a refrigerant enters the upper heat exchanging portion  40  through the upper refrigerant port  32 , and there, the refrigerant expands while flowing from an upper flat tube  23  to a lower flat tube  23 , taking heat from air passing through the upper heat exchanging portion  40 . Then, the refrigerant flows out through the lower refrigerant port  33  back to an unillustrated compressor. 
         [0063]    In the third and fourth embodiments as well, by replacing the partition panels  30  and  31  with heat-insulating partition panels  30 HI and  31 HI, respectively, it is possible to achieve further secure thermal separation. 
         [0064]    It should be understood that the embodiments specifically described above are not meant to limit the present invention, and that many variations and modifications can be made within the spirit of the present invention. 
       INDUSTRIAL APPLICABILITY 
       [0065]    The present invention is applicable to a side-flow type parallel-flow heat exchanger and an all-in-one air conditioner equipped therewith. 
       LIST OF REFERENCE SYMBOLS 
       [0000]    
       
         
           
               10  all-in-one air conditioner 
               11  housing 
               12  partition panel 
               13  cooling chamber 
               14  heat discharging room 
               17  compressor 
               18  room-air-circulation air path 
               19  heat discharging air path 
               20  parallel-flow heat exchanger 
               21 ,  22  header pipe 
               23  flat tube 
               24  refrigerant passage 
               25  fin 
               27  upper group 
               28  lower group 
               30 ,  31  partition panel 
               30 HI,  31 HI heat-insulating partition panel 
               32 ,  35  upper refrigerant port 
               33 ,  36  lower refrigerant port 
               40  upper heat exchanging portion 
               41  lower heat exchanging portion 
             HI heat insulating portion