JP2018136092A - Heat exchange unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve splitting performance at the time when a heat exchanger functions as a refrigerant evaporator, in a heat exchange unit having: a casing where a suction port is formed on a side surface and a blowout port is formed on a top surface; an air blower arranged so as to face the blowout port; and the heat exchanger arranged below the air blower.SOLUTION: A plurality of flat tubes (63) constituting a heat exchanger (11) are sectioned into a plurality of heat exchange parts (60A-60K) arranged vertically. Each heat exchange part (60A-60K) has a main heat exchange part (61A-61K), and a sub heat exchange part (62A-62K) connected to in series below the main heat exchange part through a folding communication space (92A-92K) of a header collection pipe (90). According to wind speed distribution of air, the number of flat tubes (63) constituting upper heat exchange parts (60A-60D) of the heat exchanger (11) is set smaller than the number of flat tubes (63) constituting lower heat exchange parts (60I-60K).SELECTED DRAWING: Figure 6

Description

  The present invention relates to a heat exchange unit, in particular, a casing in which a suction port is formed on a side surface and a blower outlet on a top surface, a blower disposed facing the blower port, and a heat exchange disposed on a lower side of the blower. And a heat exchanging unit.

  Conventionally, a heat exchanger having a plurality of flat tubes arranged vertically may be employed as an outdoor heat exchanger housed in an outdoor unit of an air conditioner. And as such a heat exchanger, as shown to patent document 1 (Unexamined-Japanese-Patent No. 2012-163319), the several main heat exchange part by which the several flat tube was arrange | positioned collectively on the upper part of the heat exchanger. And a plurality of sub heat exchange units arranged together below the plurality of main heat exchange units, and the main heat exchange unit and the sub heat exchange unit are connected via a communication pipe There are some in which a plurality of heat exchange portions are formed.

  Moreover, as an outdoor unit of the air conditioner, a casing having a suction port on the side and a blower outlet on the top surface, a blower arranged facing the blower outlet, and heat exchange arranged on the lower side of the blower In some cases, a heat exchanging unit (top-blow-type heat exchanging unit) is used.

  It is conceivable to employ the heat exchanger shown in Patent Document 1 as a heat exchanger that constitutes the above-described top-blow-type heat exchange unit.

  However, in the top-blow-type heat exchange unit, the heat exchanger is located below the blower, so the air velocity through the heat exchanger is higher in the upper part of the heat exchanger than in the lower part of the heat exchanger. Tend to be faster. For this reason, when the heat exchanger shown in Patent Document 1 is adopted in the top-blow-type heat exchange unit, when functioning as a refrigerant evaporator, the refrigerant flowing through the flat tube located at the top of the heat exchanger is: Since heat exchange is easier to proceed than the refrigerant flowing through the flat tubes located at the bottom of the heat exchanger, the degree of heat exchange varies between the flat tubes, and as a result, heat exchange between the heat exchange units also occurs. The bias will occur to the extent.

  In order to eliminate such a bias in the degree of heat exchange between the heat exchange units, it is necessary to appropriately divert the refrigerant to each heat exchange unit according to the wind speed distribution in the heat exchanger. However, in the heat exchanger shown in Patent Document 1, as described above, all the main heat exchange parts constituting each heat exchange part are arranged together at the upper part of the heat exchanger, and each heat exchange part is All the sub heat exchange parts to be configured are arranged together below the plurality of main heat exchange parts. Looking at this for each heat exchange part, all heat exchange parts are placed in the part placed at the top of the heat exchanger where the air wind speed is fast and the part placed at the bottom of the heat exchanger where the air wind speed is slow Therefore, it becomes difficult to match the wind speed distribution in the heat exchanger. In addition, the main heat exchange part and the sub heat exchange part are connected via a communication pipe, and the length of the communication pipe and the head difference differ greatly between the heat exchange parts. This also matches the wind speed distribution in the heat exchanger. It becomes a difficult factor.

  As described above, when the heat exchanger shown in Patent Document 1 is adopted as a heat exchanger constituting the top-blow-type heat exchange unit, when functioning as a refrigerant evaporator, the heat exchanger corresponds to the wind speed distribution in the heat exchanger. Therefore, it is difficult to appropriately divert the refrigerant to each heat exchange part, and improvement of the diversion performance is desired.

  An object of the present invention is to provide a casing having a suction port on the side and a blower outlet on the top surface, a blower disposed facing the blower outlet, and a heat exchanger disposed on the lower side of the blower. An object of the present invention is to improve the diversion performance when the heat exchanger functions as a refrigerant evaporator.

  The heat exchange unit according to the first aspect has a casing, a blower, and a heat exchanger. The casing is formed with a suction port on the side surface and an air outlet on the top surface. The blower is disposed in the casing so as to face the air outlet, and takes air into the casing from the air inlet and discharges it from the air outlet. The heat exchanger is disposed below the blower in the casing and performs heat exchange between the refrigerant and the air. The heat exchanger has a plurality of header collecting pipes standing upright, a plurality of flat pipes each having one end connected to the header collecting pipe, and a plurality of ventilation paths through which air flows between adjacent flat pipes. And fins. The flat tubes are arranged vertically and have a refrigerant passage formed therein. The plurality of flat tubes are divided into a plurality of heat exchanging portions arranged vertically. The header collecting pipe is partitioned into upper and lower interiors to form folded communication spaces corresponding to the respective heat exchange portions. Each heat exchanging part has a main heat exchanging part and a sub heat exchanging part connected in series through the folded communication space below the main heat exchanging part. And here, according to the wind speed distribution of the air in the heat exchanger, the number of flat tubes constituting the heat exchange part located at the upper part of the heat exchanger constitutes the heat exchange part located at the lower part of the heat exchanger It is set to be smaller than the number of flat tubes.

  Here, as described above, as the heat exchanger constituting the top-blow-type heat exchange unit, the sub heat connected in series through the folded communication space of the header collecting pipe below the main heat exchange part and the main heat exchange part. A configuration is adopted in which the heat exchanging section composed of the exchanging section is arranged vertically. For this reason, unlike the configuration shown in Patent Document 1, the arrangement of the heat exchanging portions is along the wind speed distribution in the heat exchanger, and the communication pipe connecting the main heat exchanging portion and the sub heat exchanging portion. Can also be eliminated.

  And here, after arranging the arrangement of such heat exchange sections along the wind speed distribution in the heat exchanger, as described above, according to the wind speed distribution of the air in the heat exchanger, The number of flat tubes constituting the heat exchanging part located in the upper part is set to be smaller than the number of flat tubes constituting the heat exchanging part located in the lower part of the heat exchanger. For this reason, the heat transfer area of the heat exchange part located in the upper part of the heat exchanger is smaller than the heat transfer area of the heat exchange part located in the lower part of the heat exchanger, and the heat exchange part located in the upper part of the heat exchanger. And the degree of heat exchange between the heat exchanger and the heat exchanger located below the heat exchanger can be eliminated.

  Thereby, according to the wind speed distribution in the heat exchanger, the refrigerant can be appropriately diverted to the respective heat exchanging portions, and the diversion when the heat exchanger functions as the refrigerant evaporator. Performance can be improved.

  The heat exchange unit according to the second aspect is the heat exchange unit according to the first aspect, wherein the number of flat tubes constituting the main heat exchange part of the heat exchange part located above the heat exchanger is the heat exchanger. The number of flat tubes constituting the main heat exchanging part of the heat exchanging part located in the lower part of the tube is smaller.

  The degree of heat exchange in each heat exchange unit is greatly affected by the size of the heat transfer area of the main heat exchange unit through which a large amount of gaseous refrigerant flows when functioning as a refrigerant evaporator.

  Therefore, here, as described above, by changing the number of flat tubes constituting the main heat exchange portion constituting each heat exchange portion, the flat tube constituting the heat exchange portion located at the top of the heat exchanger is changed. The number is set so as to be smaller than the number of flat tubes constituting the heat exchanging part located in the lower part of the heat exchanger.

  Thereby, here, the flow-dividing performance when the heat exchanger functions as a refrigerant evaporator by changing the number of flat tubes constituting the main heat exchange part that greatly affects the degree of heat exchange in each heat exchange part Can be improved.

  The heat exchange unit according to the third aspect is the heat exchange unit according to the first or second aspect, wherein the number of flat tubes constituting the heat exchange unit located at the top of the heat exchanger is the heat exchanger. It is 0.6 to 0.9 times the value obtained by dividing the total number of the flat tubes constituting by the number of heat exchange parts.

  Although there are influences such as the positional relationship between the blower and the heat exchanger, considering the air velocity distribution in the heat exchanger, the heat transfer area of the heat exchange part located at the top of the heat exchanger is The average heat transfer area of the part is preferably about 0.6 to 0.9 times.

  Therefore, here, as described above, the number of flat tubes constituting the uppermost heat exchanging portion is determined by the average number of flat tubes constituting each heat exchanging portion (that is, the total number of flat tubes constituting the heat exchanger). Is divided by the number of heat exchanging portions) to 0.6 to 0.9 times.

  Thereby, here, the heat exchanger is used as a refrigerant evaporator by setting the number of flat tubes constituting the uppermost heat exchange section to an appropriate number in consideration of the air velocity distribution in the heat exchanger. The shunt performance when functioning can be improved.

  The heat exchange unit according to the fourth aspect is the heat exchange unit according to any one of the first to third aspects, wherein the main heat exchange part for the number of flat tubes constituting the sub heat exchange part in each heat exchange part is provided. The ratio of the number of the flat tubes to comprise is 1.5-4.5.

  When the heat exchanger functions as a refrigerant evaporator, in each heat exchanging part, the refrigerant that has flowed back from the sub heat exchanging part into the communicating space is divided and sent to the flat tubes constituting the main heat exchanging part. At this time, since a large amount of gas refrigerant flows through the main heat exchange section, the number of flat tubes constituting the main heat exchange section is sub-heat exchange from the viewpoint of reducing pressure loss and securing a heat transfer area. The number is preferably larger than the number of flat tubes constituting the portion. However, if the number of flat tubes constituting the main heat exchange part is increased too much, it becomes difficult to divert from the folded communication space to the flat pipes constituting the main heat exchange part. It is preferable that the ratio of the number of flat tubes constituting the main heat exchange portion to the number of flat tubes constituting the sub heat exchange portion is within a certain range.

  Therefore, here, as described above, the ratio of the number of flat tubes constituting the main heat exchange unit to the number of flat tubes constituting the sub heat exchange unit in each heat exchange unit is 1.5 to 4.5. Within the range.

  Thus, here, the ratio of the number of flat tubes constituting the main heat exchange portion to the number of flat tubes constituting the sub heat exchange portion in each heat exchange portion is calculated from the flat communication space constituting the main heat exchange portion from the folded communication space. By setting an appropriate ratio in consideration of the diversion to the pipe, it is possible to improve the diversion performance when the heat exchanger functions as a refrigerant evaporator.

  The heat exchange unit according to the fifth aspect is a position corresponding to the boundary between the main heat exchange part and the sub heat exchange part among the plurality of fins in the heat exchange unit according to any one of the first to fourth aspects. Further, a fin cutting portion that suppresses heat conduction in the vertical direction at the boundary portion is formed.

  As a heat exchanger, when adopting a configuration in which the heat exchange part composed of the sub heat exchange part connected in series through the folded communication space of the header collecting pipe below the main heat exchange part and the main heat exchange part is arranged vertically, Heat conduction through the fins occurs between the main heat exchange unit and the adjacent sub heat exchange unit. When this heat conduction occurs, when the heat exchanger functions as a refrigerant evaporator, the main heat exchanging part is cooled by the adjacent sub heat exchanging part, and the refrigerant flowing through the main heat exchanging part is heated. May become insufficient, and the evaporation performance of the heat exchanger may be reduced. Further, when the heat exchanger functions as a refrigerant radiator, the sub heat exchange part is heated by the adjacent main heat exchange part, and cooling of the refrigerant flowing through the sub heat exchange part becomes insufficient. As a result, the heat dissipation performance of the heat exchanger may be reduced.

  Therefore, here, as described above, a fin cutting portion that suppresses heat conduction in the vertical direction at the boundary portion is formed at a position corresponding to the boundary portion between the main heat exchange portion and the sub heat exchange portion among the plurality of fins. Like to do.

  Thereby, here, the fin cutting part can suppress heat conduction through the fins generated between the main heat exchanging part and the adjacent sub heat exchanging part, and the heat exchanger evaporating performance and heat dissipation performance are reduced. Can be suppressed.

  As described in the above description, according to the present invention, in the top-blow type heat exchange unit, it is possible to appropriately divert the refrigerant to each heat exchange unit according to the wind speed distribution in the heat exchanger. Thus, it is possible to improve the diversion performance when the heat exchanger functions as a refrigerant evaporator.

It is a schematic block diagram of the air conditioning apparatus by which the outdoor unit as a heat exchange unit concerning one Embodiment of this invention was employ | adopted. It is an external appearance perspective view of an outdoor unit. It is a front view of an outdoor unit (shown excluding refrigerant circuit components other than the outdoor heat exchanger). It is a schematic perspective view of an outdoor heat exchanger. It is the elements on larger scale of the heat exchange part of FIG. It is a schematic block diagram of an outdoor heat exchanger. It is a schematic block diagram of the outdoor heat exchanger which the outdoor unit as a heat exchange unit concerning a modification has. It is a figure which shows a part of II cross section of the outdoor heat exchanger of FIG.

  Hereinafter, an embodiment of an outdoor unit as a heat exchange unit according to the present invention and a modification thereof will be described based on the drawings. In addition, the concrete structure of the outdoor unit as a heat exchange unit concerning this invention is not restricted to the following embodiment and its modification, It can change in the range which does not deviate from the summary of invention.

(1) Configuration of Air Conditioner FIG. 1 is a schematic configuration diagram of an air conditioner 1 that employs an outdoor unit 2 as a heat exchange unit according to an embodiment of the present invention.

  The air conditioner 1 is a device capable of cooling and heating a room such as a building by performing a vapor compression refrigeration cycle. The air conditioner 1 mainly includes an outdoor unit 2, indoor units 3a and 3b, a liquid refrigerant communication tube 4 and a gas refrigerant communication tube 5 that connect the outdoor unit 2 and the indoor units 3a and 3b, an outdoor unit 2 and And a control unit 23 that controls the constituent devices of the indoor units 3a and 3b. The vapor compression refrigerant circuit 6 of the air conditioner 1 is configured by connecting the outdoor unit 2 and the indoor units 3 a and 3 b via the refrigerant communication tubes 4 and 5.

  The outdoor unit 2 is installed outdoors (on the roof of a building, in the vicinity of the wall surface of the building, etc.) and constitutes a part of the refrigerant circuit 6. The outdoor unit 2 mainly includes an accumulator 7, a compressor 8, a four-way switching valve 10, an outdoor heat exchanger 11, an outdoor expansion valve 12 as an expansion mechanism, a liquid side shut-off valve 13, and a gas side shut-off valve. 14 and an outdoor fan 15. Each device and the valve are connected by refrigerant pipes 16 to 22.

  The indoor units 3 a and 3 b are installed indoors (such as a living room or a ceiling space) and constitute a part of the refrigerant circuit 6. The indoor unit 3a mainly has an indoor expansion valve 31a, an indoor heat exchanger 32a, and an indoor fan 33a. The indoor unit 3b mainly includes an indoor expansion valve 31b as an expansion mechanism, an indoor heat exchanger 32b, and an indoor fan 33b.

  The refrigerant communication pipes 4 and 5 are refrigerant pipes that are constructed on site when the air conditioner 1 is installed at an installation location such as a building. One end of the liquid refrigerant communication tube 4 is connected to the liquid side closing valve 13 of the indoor unit 2, and the other end of the liquid refrigerant communication tube 4 is connected to the liquid side ends of the indoor expansion valves 31a and 31b of the indoor units 3a and 3b. Has been. One end of the gas refrigerant communication pipe 5 is connected to the gas side shut-off valve 14 of the indoor unit 2, and the other end of the gas refrigerant communication pipe 5 is connected to the gas side ends of the indoor heat exchangers 32a and 32b of the indoor units 3a and 3b. It is connected.

  The control unit 23 is configured by communication connection of control boards and the like (not shown) provided in the outdoor unit 2 and the indoor units 3a and 3b. In FIG. 1, for the sake of convenience, the outdoor unit 2 and the indoor units 3a and 3b are illustrated at positions away from each other. The control unit 23 controls the components 8, 10, 12, 15, 31a, 31b, 33a, 33b of the air conditioner 1 (here, the outdoor unit 2 and the indoor units 3a, 3b), that is, the air conditioner 1 The whole operation control is performed.

(2) Operation | movement of an air conditioning apparatus Next, operation | movement of the air conditioning apparatus 1 is demonstrated using FIG. In the air conditioner 1, the cooling operation in which the refrigerant flows in the order of the compressor 8, the outdoor heat exchanger 11, the outdoor expansion valve 12, the indoor expansion valves 31a and 31b, and the indoor heat exchangers 32a and 32b, the compressor 8, and the indoor heat A heating operation is performed in which the refrigerant flows in the order of the exchangers 32a and 32b, the indoor expansion valves 31a and 31b, the outdoor expansion valve 12, and the outdoor heat exchanger 11. The cooling operation and the heating operation are performed by the control unit 23.

  During the cooling operation, the four-way switching valve 10 is switched to the outdoor heat dissipation state (the state shown by the solid line in FIG. 1). In the refrigerant circuit 6, the low-pressure gas refrigerant in the refrigeration cycle is sucked into the compressor 8 and is compressed until it reaches the high pressure in the refrigeration cycle, and then discharged. The high-pressure gas refrigerant discharged from the compressor 8 is sent to the outdoor heat exchanger 11 through the four-way switching valve 10. The high-pressure gas refrigerant sent to the outdoor heat exchanger 11 dissipates heat by exchanging heat with outdoor air supplied as a cooling source by the outdoor fan 15 in the outdoor heat exchanger 11 that functions as a refrigerant radiator. Become a high-pressure liquid refrigerant. The high-pressure liquid refrigerant radiated in the outdoor heat exchanger 11 is sent to the indoor expansion valves 31 a and 31 b through the outdoor expansion valve 12, the liquid-side closing valve 13, and the liquid refrigerant communication pipe 4. The refrigerant sent to the indoor expansion valves 31a and 31b is decompressed to the low pressure of the refrigeration cycle by the indoor expansion valves 31a and 31b, and becomes a low-pressure gas-liquid two-phase refrigerant. The low-pressure gas-liquid two-phase refrigerant decompressed by the indoor expansion valves 31a and 31b is sent to the indoor heat exchangers 32a and 32b. The low-pressure gas-liquid two-phase refrigerant sent to the indoor heat exchangers 32a and 32b exchanges heat with indoor air supplied as a heating source by the indoor fans 33a and 33b in the indoor heat exchangers 32a and 32b. Evaporate. As a result, the room air is cooled and then supplied to the room to cool the room. The low-pressure gas refrigerant evaporated in the indoor heat exchangers 32 a and 32 b is again sucked into the compressor 8 through the gas refrigerant communication pipe 5, the gas side closing valve 14, the four-way switching valve 10, and the accumulator 7.

  During the heating operation, the four-way selector valve 10 is switched to the outdoor evaporation state (the state indicated by the broken line in FIG. 1). In the refrigerant circuit 6, the low-pressure gas refrigerant in the refrigeration cycle is sucked into the compressor 8 and is compressed until it reaches the high pressure in the refrigeration cycle, and then discharged. The high-pressure gas refrigerant discharged from the compressor 8 is sent to the indoor heat exchangers 32 a and 32 b through the four-way switching valve 10, the gas side closing valve 14, and the gas refrigerant communication pipe 5. The high-pressure gas refrigerant sent to the indoor heat exchangers 32a and 32b dissipates heat by exchanging heat with indoor air supplied as a cooling source by the indoor fans 33a and 33b in the indoor heat exchangers 32a and 32b. Becomes a high-pressure liquid refrigerant. Thereby, indoor air is heated, and indoor heating is performed by being supplied indoors after that. The high-pressure liquid refrigerant radiated by the indoor heat exchangers 32 a and 32 b is sent to the outdoor expansion valve 12 through the indoor expansion valves 31 a and 31 b, the liquid refrigerant communication tube 4 and the liquid-side closing valve 13. The refrigerant sent to the outdoor expansion valve 12 is decompressed to the low pressure of the refrigeration cycle by the outdoor expansion valve 12, and becomes a low-pressure gas-liquid two-phase refrigerant. The low-pressure gas-liquid two-phase refrigerant decompressed by the outdoor expansion valve 12 is sent to the outdoor heat exchanger 11. The low-pressure gas-liquid two-phase refrigerant sent to the outdoor heat exchanger 11 exchanges heat with outdoor air supplied as a heating source by the outdoor fan 15 in the outdoor heat exchanger 11 that functions as a refrigerant evaporator. Go and evaporate into a low-pressure gas refrigerant. The low-pressure refrigerant evaporated in the outdoor heat exchanger 11 is again sucked into the compressor 8 through the four-way switching valve 10 and the accumulator 7.

(3) Configuration of Outdoor Unit FIG. 2 is an external perspective view of the outdoor unit 2. FIG. 3 is a front view of the outdoor unit 2 (illustrated excluding refrigerant circuit components other than the outdoor heat exchanger 11). FIG. 4 is a schematic perspective view of the outdoor heat exchanger 11. FIG. 5 is a partially enlarged view of the heat exchange units 60A to 60K in FIG. FIG. 6 is a schematic configuration diagram of the outdoor heat exchanger 11.

<Overall>
The outdoor unit 2 is a top blow type heat exchange unit that sucks air from the side surface of the casing 40 and blows air from the top surface of the casing 40. The outdoor unit 2 mainly includes a substantially rectangular parallelepiped box-shaped casing 40, an outdoor fan 15 as a blower, devices 7, 8, 11 such as a compressor and an outdoor heat exchanger, a four-way switching valve, an outdoor expansion valve, and the like. And refrigerant circuit components that constitute a part of the refrigerant circuit 6 including the valves 10, 12 to 14, the refrigerant pipes 16 to 22, and the like. In the following description, “top”, “bottom”, “left”, “right”, “front”, “back”, “front”, and “back” are shown in FIG. 2 unless otherwise specified. The direction when the outdoor unit 2 to be viewed is viewed from the front (left oblique front side of the drawing) is meant.

  The casing 40 mainly includes a bottom frame 42 that spans a pair of installation legs 41 that extend in the left-right direction, a column 43 that extends vertically from a corner of the bottom frame 42, and a fan module 44 that is attached to the upper end of the column 43. And a front panel 45, and air inlets 40a, 40b, 40c are formed on the side surfaces (here, the rear surface and the left and right side surfaces), and an air outlet 40d is formed on the top surface.

  The bottom frame 42 forms the bottom surface of the casing 40, and the outdoor heat exchanger 11 is provided on the bottom frame 42. Here, the outdoor heat exchanger 11 is a substantially U-shaped heat exchanger in plan view facing the back surface and both left and right side surfaces of the casing 40, and substantially forms the back surface and both left and right side surfaces of the casing 40. .

  A fan module 44 is provided on the upper side of the outdoor heat exchanger 11, and forms a portion above the front and rear surfaces of the casing 40 and the right and left both-side support columns 43 and the top surface of the casing 40. . Here, the fan module 44 is an assembly in which the outdoor fan 15 is accommodated in a substantially rectangular parallelepiped box having an upper surface and a lower surface opened. The opening on the top surface of the fan module 44 is an air outlet 40d, and an air outlet grill 46 is provided at the air outlet 40d. The outdoor fan 15 is disposed in the casing 40 so as to face the air outlet 40d, and is a blower that takes air into the casing 40 from the suction ports 40a, 40b, and 40c and discharges it from the air outlet 40d.

  The front panel 45 is spanned between the support columns 43 on the front side, and forms the front surface of the casing 40.

  In the casing 40, refrigerant circuit components other than the outdoor fan 15 and the outdoor heat exchanger 11 (in FIG. 2, the accumulator 7, the compressor 8, and the refrigerant pipes 16 to 18 are shown) are also housed. Here, the compressor 8 and the accumulator 7 are provided on the bottom frame 42.

  As described above, the outdoor unit 2 includes the casing 40 in which the air suction ports 40a, 40b, and 40c are formed on the side surfaces (here, the rear surface and the left and right side surfaces), and the air outlet 40d is formed on the top surface. It has the outdoor fan 15 arrange | positioned facing the blower outlet 40d in the inside, and the outdoor heat exchanger 11 arrange | positioned in the casing 40 under the outdoor fan 15 inside. In such a top-blow type unit configuration, the outdoor heat exchanger 11 is disposed below the outdoor fan 15, and therefore the wind speed of the air passing through the outdoor heat exchanger 11 is different from that of the outdoor heat exchanger 11. The upper part tends to be faster than the lower part of the outdoor heat exchanger 11 (see FIG. 3).

<Outdoor heat exchanger>
The outdoor heat exchanger 11 is a heat exchanger that performs heat exchange between the refrigerant and the outdoor air, and mainly includes a first header collecting pipe 80, a second header collecting pipe 90, a plurality of flat tubes 63, and a plurality of flat tubes 63. And fins 64. Here, all of the first header collecting pipe 80, the second header collecting pipe 90, the flat pipe 63, and the fins 64 are formed of aluminum or an aluminum alloy, and are joined to each other by brazing or the like.

  Each of the first header collecting pipe 80 and the second header collecting pipe 90 is a vertically long hollow cylindrical member. The first header collecting pipe 80 is erected on one end side of the outdoor heat exchanger 11 (here, the left front end side in FIG. 4 or the left end side in FIG. 6), and the second header collecting pipe 90 is It is erected on the other end side of the outdoor heat exchanger 11 (here, the right front end side in FIG. 4 or the right end side in FIG. 6).

  The flat tube 63 is a flat multi-hole tube having a flat portion 63a facing the vertical direction as a heat transfer surface and a large number of small passages 63b through which the refrigerant flows. A plurality of flat tubes 63 are arranged vertically, and both ends thereof are connected to the first header collecting tube 80 and the second header collecting tube 90. The fins 64 are partitioned into a plurality of ventilation paths through which air flows between adjacent flat tubes 63, and a plurality of cutouts 64a extending horizontally are formed so that the plurality of flat tubes 63 can be inserted. . The shape of the notch 64 a of the fin 64 substantially matches the outer shape of the cross section of the flat tube 63.

  In the outdoor heat exchanger 11, the plurality of flat tubes 63 are divided into a plurality (here, 11) of heat exchange units 60A to 60K arranged vertically. Specifically, the first heat exchange unit 60A, the second heat exchange unit 60B,... The tenth heat exchange unit 60J, and the eleventh heat exchange unit 60K are formed in this order from top to bottom. . Each of the first to fourth heat exchange units 60A to 60D has seven flat tubes 63. Each of the fifth to eighth heat exchanging units 60E to 60H has eight flat tubes 63. Each of the ninth to eleventh heat exchange units 60I to 60K has nine flat tubes 63.

  The first header collecting pipe 80 is partitioned into upper and lower portions by a partition plate 81, thereby forming entrance / exit communication spaces 82A to 82K corresponding to the heat exchange units 60A to 60K. Each of the inlet / outlet communication spaces 82A to 82K is further partitioned vertically by a partition plate 83 to form upper gas side inlet / outlet communication spaces 84A to 84K and lower liquid side inlet / outlet communication spaces 85A to 85K. Has been. And each liquid side inlet-and-outlet communication space 85A-85K is connected to the two flat tubes 63 from the bottom among the flat tubes 63 which comprise the corresponding heat exchange parts 60A-60K, and each gas side inlet-and-outlet communication space 84A-84K. Are communicated with the rest of the flat tubes 63 constituting the corresponding heat exchange parts 60A to 60K. Here, the flat tubes 63 communicating with the gas side inlet / outlet communication spaces 84A to 84K are referred to as main heat exchanging portions 61A to 61K, and the flat tubes 63 communicating with the liquid side inlet / outlet communication spaces 85A to 85K are sub heat exchanging portions 62A to 62A. 62K. That is, in the first to fourth inlet / outlet communication spaces 82 </ b> A to 82 </ b> D, the first to fourth liquid side inlet / outlet communication spaces 85 </ b> A to 85 </ b> D are arranged from the bottom of the flat tubes 63 constituting the first to fourth heat exchange portions 60 </ b> A to 60 </ b> D. The flat tubes 63 communicated with the two flat tubes 63 (sub heat exchange portions 62A to 62D), and the first to fourth gas side inlet / outlet communication spaces 84A to 84D constitute the first to fourth heat exchange portions 60A to 60D. (The main heat exchanging portions 61A to 61D). In the fifth to eighth inlet / outlet communication spaces 82 </ b> E to 82 </ b> H, the fifth to eighth liquid side inlet / outlet communication spaces 85 </ b> E to 85 </ b> H are two from the bottom among the flat tubes 63 constituting the fifth to eighth heat exchange units 60 </ b> E to 60 </ b> H. Of the flat tube 63 (sub heat exchange portions 62E to 62H), and the fifth to eighth gas side inlet / outlet communication spaces 84E to 84H constitute the fifth to eighth heat exchange portions 60E to 60H. It communicates with six (main heat exchange parts 61E-61H). In the ninth to eleventh inlet / outlet communication spaces 82I to 82K, the ninth to eleventh liquid side inlet / outlet communication spaces 85I to 85K are two from the bottom among the flat tubes 63 constituting the ninth to eleventh heat exchange portions 60I to 60K. Of the flat tube 63 (sub heat exchange portions 62I to 62K) and the ninth to eleventh gas side inlet / outlet communication spaces 84I to 84K constitute the ninth to eleventh heat exchange portions 60I to 60K. It communicates with seven (main heat exchanging parts 61I to 61K).

  Further, the first header collecting pipe 80 includes a liquid side diverting member 70 for diverting the refrigerant sent from the outdoor expansion valve 12 during the heating operation to the liquid side inlet / outlet communication spaces 85A to 85K, and the compressor 8 during the cooling operation. Are connected to gas side branching members 75 that branch off the refrigerant sent from each of the gas side inlet / outlet communication spaces 84A to 84K.

  The liquid side diverting member 70 extends from the liquid side refrigerant diverter 71 connected to the refrigerant pipe 20 (see FIG. 1) and the liquid side refrigerant diverter 71, and is connected to the liquid side inlet / outlet communication spaces 85A to 85K. Liquid side refrigerant distribution pipes 72A to 72K.

  The gas side branch member 75 extends from the gas side refrigerant branch mother pipe 76 connected to the refrigerant pipe 19 (see FIG. 1) and the gas side refrigerant branch mother pipe 76 and is connected to the gas side inlet / outlet communication spaces 84A to 84K. Gas side refrigerant branch branch pipes 77A to 77K.

  As for the 2nd header collection pipe 90, the internal space is divided up and down by the partition plate 91, and the return | turnback communication space 92A-92K corresponding to each heat exchange part 60A-60K is formed. And each return | turnback communication space 92A-92K is connected to all the flat tubes 63 which comprise the corresponding heat exchange parts 60A-60K. That is, the first to fourth folded communication spaces 92A to 92D communicate with all of the seven flat tubes 63 constituting the first to fourth heat exchange units 60A to 60D. The fifth to eighth folded communication spaces 92E to 92H communicate with all of the eight flat tubes 63 constituting the fifth to eighth heat exchange portions 60E to 60H. The ninth to eleventh folded communication spaces 92I to 92K communicate with all the nine flat tubes 63 constituting the ninth to eleventh heat exchange portions 60I to 60K.

  Thereby, each heat exchange part 60A-60K is sub heat exchange part 62A-62K connected in series through the turn back communication space 92A-92K under the main heat exchange parts 61A-61K and the main heat exchange parts 61A-61K. And have. That is, the heat exchange units 60A to 60D are positioned directly below the flat tubes 63 constituting the main heat exchange units 61A to 61D communicating with the gas side inlet / outlet communication spaces 84A to 84D and the main heat exchange units 61A to 61D. The flat tubes 63 constituting the sub heat exchange portions 62A to 62D communicating with the liquid side inlet / outlet communication spaces 85A to 85D are connected in series through the folded communication spaces 92A to 92D. The heat exchange parts 60E-60H are located directly below the flat tubes 63 constituting the main heat exchange parts 61E-61H communicating with the gas side inlet / outlet communication spaces 84E-84H and the main heat exchange parts 61E-61H. The flat pipe 63 which comprises the sub heat exchange parts 62E-62H connected to the side entrance / exit communication space 85E-85H has the structure connected in series through the return | turnback communication space 92E-92H. The heat exchangers 60I to 60K are located directly below the flat tubes 63 constituting the main heat exchangers 61I to 61K communicating with the gas side inlet / outlet communication spaces 84I to 84K and the main heat exchangers 61I to 61K. The flat pipe 63 which comprises the sub heat exchange parts 62I-62K connected to the side entrance / exit communication space 85I-85K has the structure connected in series through the return | turnback communication space 92I-92K.

  And here, according to the wind speed distribution of the air of the outdoor heat exchanger 11, as described above, the number of the flat tubes 63 constituting the heat exchanging portions 60A to 60D positioned above the outdoor heat exchanger 11 (7 Is set to be smaller than the number (9) of flat tubes 63 constituting the heat exchanging portions 60I to 60K located in the lower part of the outdoor heat exchanger 11.

  Here, the number (7) of flat tubes 63 constituting the first heat exchanging portion 60 </ b> A located at the top of the outdoor heat exchanger 11 is equal to the total number of flat tubes 63 constituting the outdoor heat exchanger 11 ( 87) is divided by the number (11) of the heat exchange parts 60A to 60K, which is 0.6 to 0.9 times. In addition, the number of the heat exchange parts in the outdoor heat exchanger 11 may be 10 or less, may be 12 or more, and is set according to the height of the outdoor heat exchanger 11 or the like.

  Here, the number (five) of the flat tubes 63 constituting the main heat exchanging parts 61A to 61D of the heat exchanging parts 60A to 60D located at the upper part of the outdoor heat exchanger 11 is the lower part of the outdoor heat exchanger 11. The number of the flat tubes 63 constituting the main heat exchanging parts 61I to 61K of the heat exchanging parts 60I to 60K located at the number (seven) is smaller.

  Further, here, the number of flat tubes 63 constituting the main heat exchange portions 61A to 61K (5) with respect to the number (two) of the flat tubes 63 constituting the sub heat exchange portions 62A to 62K in the respective heat exchange portions 60A to 60K (5). ˜7) is 1.5 to 4.5.

  Next, the flow of the refrigerant in the outdoor heat exchanger 11 having the above configuration will be described.

  During the cooling operation, the outdoor heat exchanger 11 functions as a radiator for the refrigerant discharged from the compressor 8.

  The refrigerant discharged from the compressor 8 is sent to the gas-side branch member 75 through the refrigerant pipe 19 (see FIG. 1). The refrigerant sent to the gas side diverting member 75 is diverted from the gas side refrigerant diverting mother pipe 76 to the gas side refrigerant diverting branch pipes 77A to 77K, so that the gas side inlet / outlet communication spaces 84A to 84A of the first header collecting pipe 80 are diverted. Sent to 84K.

  The refrigerant sent to each of the gas side inlet / outlet communication spaces 84A to 84K is diverted to the flat tubes 63 constituting the main heat exchange units 61A to 61K of the corresponding heat exchange units 60A to 60K. The refrigerant sent to each flat tube 63 is dissipated by heat exchange with outdoor air while flowing through the passage 63b, and merges in each of the folded communication spaces 92A to 92K of the second header collecting tube 90. That is, the refrigerant passes through the main heat exchange units 61A to 61K. At this time, the refrigerant dissipates heat from the superheated gas state until it becomes a liquid state close to a gas-liquid two-phase state or a saturated state.

  The refrigerant merged in each of the folded communication spaces 92A to 92K is diverted to the flat tubes 63 constituting the sub heat exchange units 62A to 62K of the corresponding heat exchange units 60A to 60K. The refrigerant sent to each flat tube 63 is dissipated by heat exchange with outdoor air while flowing through the passage 63b, and merges in the liquid side inlet / outlet communication spaces 85A to 85K of the first header collecting pipe 80. That is, the refrigerant passes through the sub heat exchange units 62A to 62K. At this time, the refrigerant further dissipates heat until it becomes a supercooled liquid state from a liquid state close to a gas-liquid two-phase state or a saturated state.

  The refrigerant sent to each of the liquid side inlet / outlet communication spaces 85 </ b> A to 85 </ b> K is sent to the liquid side refrigerant distribution pipes 72 </ b> A to 72 </ b> K of the liquid side refrigerant distribution member 70 and merges in the liquid side refrigerant distribution device 71. The refrigerant merged in the liquid side refrigerant divider 71 is sent to the outdoor expansion valve 12 (see FIG. 1) through the refrigerant pipe 20 (see FIG. 1).

  During the heating operation, the outdoor heat exchanger 11 functions as an evaporator for the refrigerant decompressed by the outdoor expansion valve 12 (see FIG. 1).

  The refrigerant decompressed in the outdoor expansion valve 12 is sent to the liquid side refrigerant distribution member 70 through the refrigerant pipe 20 (see FIG. 1). The refrigerant sent to the liquid side refrigerant diverting member 70 is diverted from the liquid side refrigerant diverter 71 to the liquid side refrigerant diversion pipes 72A to 72K, and the liquid side inlet / outlet communication spaces 85A to 85K of the first header collecting pipe 80 are diverted. Sent to.

  The refrigerant sent to the liquid side inlet / outlet communication spaces 85A to 85K is diverted to the flat tubes 63 constituting the sub heat exchange units 62A to 62K of the corresponding heat exchange units 60A to 60K. The refrigerant sent to each flat tube 63 evaporates by heat exchange with outdoor air while flowing through the passage 63b, and merges in the folded communication spaces 92A to 92K of the second header collecting tube 90. That is, the refrigerant passes through the sub heat exchange units 62A to 62K. At this time, the refrigerant evaporates from a gas-liquid two-phase state with a lot of liquid components to a gas state close to a saturated state with a gas-liquid two-phase state with many gas components.

  The refrigerant merged in each of the folded communication spaces 92A to 92K is diverted to the flat tubes 63 constituting the main heat exchange units 61A to 61K of the corresponding heat exchange units 60A to 60K. The refrigerant sent to each flat tube 63 is evaporated (heated) by heat exchange with outdoor air while flowing through the passage 63b, and the gas side inlet / outlet communication spaces 84A to 84K of the first header collecting pipe 80 are evaporated. Join in. That is, the refrigerant passes through the main heat exchange units 61A to 61K. At this time, the refrigerant is further evaporated (heated) from a gas-liquid two-phase state with a lot of gas components or a gas state close to saturation to a superheated gas state.

  The refrigerant sent to the gas side inlet / outlet communication spaces 84 </ b> A to 84 </ b> K is sent to the gas side refrigerant branch branches 77 </ b> A to 77 </ b> K of the gas side refrigerant diverting member 75 and merges in the gas side refrigerant diversion main pipe 76. The refrigerant merged in the gas-side refrigerant branch mother pipe 76 is sent to the suction side of the compressor 8 (see FIG. 1) through the refrigerant pipe 19 (see FIG. 1).

(4) Features The outdoor unit 2 of the present embodiment has the following features.

<A>
Here, as described above, the main heat exchange units 61A to 61K and the main heat exchange units 61A to 61K are used as the outdoor heat exchanger 11 (heat exchanger) constituting the top-blowing outdoor unit 2 (heat exchange unit). The heat exchanging parts 60A to 60K composed of the sub heat exchanging parts 62A to 62K connected in series through the folded communication spaces 92A to 92K of the header collecting pipe 90 are arranged vertically. For this reason, unlike the configuration shown in Patent Document 1, the arrangement of the heat exchange units 60A to 60K follows the wind speed distribution in the heat exchanger, and the main heat exchange units 61A to 61K and the sub heat exchange unit A communication pipe connecting 62A to 62K can also be eliminated.

  And here, after arranging such an arrangement of the heat exchangers 60A to 60K along the wind speed distribution in the outdoor heat exchanger 11, the air speed distribution of the air in the outdoor heat exchanger 11 is changed as described above. Accordingly, the number of flat tubes 63 constituting the heat exchange units 60 </ b> A to 60 </ b> D located at the upper part of the outdoor heat exchanger 11 corresponds to the flat tubes constituting the heat exchange units 60 </ b> I to 60 </ b> K located at the lower part of the outdoor heat exchanger 11. The number is set to be smaller than 63. For this reason, the heat transfer area of the heat exchange units 60A to 60D located at the upper part of the outdoor heat exchanger 11 is smaller than the heat transfer area of the heat exchange parts 60I to 60K located at the lower part of the outdoor heat exchanger 11, so that the outdoor The bias of the degree of heat exchange between the heat exchange units 60A to 60D located at the upper part of the heat exchanger 11 and the heat exchange parts 60I to 60K located at the lower part of the outdoor heat exchanger 11 can be eliminated.

  Thereby, according to the wind speed distribution in the outdoor heat exchanger 11, a refrigerant | coolant can now be appropriately shunted with respect to each heat exchange part 60A-60K, and the outdoor heat exchanger 11 is made to evaporate a refrigerant | coolant. The shunt performance when functioning as a heater (here, during heating operation) can be improved.

<B>
The degree of heat exchange in each of the heat exchange units 60A to 60K is greatly affected by the size of the heat transfer area of the main heat exchange units 61A to 61K through which a large amount of gaseous refrigerant flows when functioning as a refrigerant evaporator.

  Therefore, here, as described above, the number of the flat tubes 63 constituting the main heat exchanging parts 61A to 61K constituting the heat exchanging parts 60A to 60K is changed to be positioned above the outdoor heat exchanger 11. It sets so that the number of the flat tubes 63 which comprise the heat exchange parts 60A-60D may be smaller than the number of the flat tubes 63 which comprise the heat exchange parts 60I-60K located in the lower part of the outdoor heat exchanger 11. .

  Thereby, here, by changing the number of the flat tubes 63 constituting the main heat exchanging parts 61A to 61K that greatly influence the degree of heat exchanging in each of the heat exchanging parts 60A to 60K, the outdoor heat exchanger 11 is made of the refrigerant. The shunting performance when functioning as an evaporator can be improved.

<C>
Although there is an influence such as the positional relationship between the outdoor fan 15 (blower) and the outdoor heat exchanger 11, in consideration of the air velocity distribution in the outdoor heat exchanger 11, the heat exchange located at the top of the outdoor heat exchanger 11. The heat transfer area of the part 60A is preferably about 0.6 to 0.9 times the average heat transfer area of the heat exchange parts 60A to 60K.

  Therefore, here, as described above, the number of the flat tubes 63 constituting the uppermost heat exchanging portion 60A is set to the average number of the flat tubes 63 constituting the respective heat exchanging portions 60A to 60K (that is, the outdoor heat exchangers). 11 is a value obtained by dividing the total number of flat tubes 63 constituting 11 by the number of heat exchange parts 60A to 60K).

  Thereby, here, the number of the flat tubes 63 constituting the uppermost heat exchange section 60A is set to an appropriate number in consideration of the air velocity distribution in the outdoor heat exchanger 11, so that the outdoor heat exchanger 11 It is possible to improve the shunting performance when functioning as a refrigerant evaporator.

<D>
When the outdoor heat exchanger 11 is caused to function as a refrigerant evaporator, in each of the heat exchange units 60A to 60K, the refrigerant that has flowed back from the sub heat exchange units 62A to 62K into the communication spaces 92A to 92K is the main heat exchange unit 61A. It is divided and sent to the flat tube 63 constituting ˜6K. At this time, since a large amount of gaseous refrigerant flows through the main heat exchanging parts 61A to 61K, the flat tubes 63 constituting the main heat exchanging parts 61A to 61K are used from the viewpoint of reducing pressure loss and securing a heat transfer area. It is preferable to make the number larger than the number of flat tubes 63 constituting the sub heat exchange parts 62A to 62K. However, if the number of the flat tubes 63 constituting the main heat exchanging portions 61A to 61K is excessively increased, it becomes difficult to divert the folded communication spaces 92A to 62K to the flat tubes 63 constituting the main heat exchanging portions 61A to 61K. In consideration of this, the ratio of the number of the flat tubes 63 constituting the main heat exchange portions 61A to 61K to the number of the flat tubes 63 constituting the sub heat exchange portions 62A to 62K in the respective heat exchange portions 60A to 60K to some extent It is preferable to be within the range.

  Therefore, here, as described above, the number of flat tubes 63 constituting the main heat exchange portions 61A to 61K with respect to the number of flat tubes 63 constituting the sub heat exchange portions 62A to 62K in the respective heat exchange portions 60A to 60K. The ratio is set within the range of 1.5 to 4.5.

  Thereby, here, the ratio of the number of the flat tubes 63 constituting the main heat exchange portions 61A to 61K to the number of the flat tubes 63 constituting the sub heat exchange portions 62A to 62K in the respective heat exchange portions 60A to 60K is folded back. A diversion when the outdoor heat exchanger 11 is caused to function as a refrigerant evaporator by setting an appropriate ratio in consideration of the diversion from the communication spaces 92A to 92K to the flat tubes 63 constituting the main heat exchange portions 61A to 61K. Performance can be improved.

(5) Modification <A>
As the outdoor heat exchanger 11 (heat exchanger), sub heat exchanges connected in series through the folded communication spaces 92A to 92K of the header collecting pipe 90 below the main heat exchange portions 61A to 61K and the main heat exchange portions 61A to 61K. When the heat exchanging parts 60A to 60K composed of the parts 62A to 62K are vertically arranged, heat through the fins 64 between the main heat exchanging parts 61A to 61K and the adjacent sub heat exchanging parts 62A to 62K. Conduction occurs. When this heat conduction occurs, when the outdoor heat exchanger 11 is caused to function as a refrigerant evaporator (here, during heating operation), the main heat exchange units 61A to 61K are moved by the adjacent sub heat exchange units 62A to 62K. As a result, the refrigerant flowing through the main heat exchange units 61A to 61K is not sufficiently heated, and the evaporation performance of the outdoor heat exchanger 11 may be deteriorated. Further, when the outdoor heat exchanger 11 functions as a refrigerant radiator (here, during cooling operation), the sub heat exchange units 62A to 62K are heated by the adjacent main heat exchange units 61A to 61K. Therefore, the cooling of the refrigerant flowing through the sub heat exchange units 62A to 62K becomes insufficient, and the heat dissipation performance of the outdoor heat exchanger 11 may be deteriorated.

  Therefore, here, as shown in FIG. 7 and FIG. 8, the upper and lower sides of the plurality of fins 64 are located at positions corresponding to the boundary between the main heat exchange units 61 </ b> A to 61 </ b> K and the sub heat exchange units 62 </ b> A to 62 </ b> K. The fin cutting part 64b which suppresses heat conduction in the direction is formed. Here, the fin cutting part 64b is formed from one end to the other end in the refrigerant flow direction (that is, the longitudinal direction of the flat tube 63) of the heat exchange parts 60A to 60K (see FIG. 7). Moreover, the fin cutting part 64b is horizontal so as to cross between the flat tube 63 constituting the main heat exchange parts 61A to 61K and the flat pipe 63 constituting the sub heat exchange parts 62A to 62K adjacent thereto. It is formed in a slit shape extending elongated. The fin cutting part 64b may not be formed from one end to the other end in the refrigerant flow direction of the heat exchange parts 60A to 60K, and the main heat exchange parts 61A to 61K and the sub heat exchange parts 62A to 62K. It may be formed only in a portion near the first header collecting pipe 80 (portion close to the refrigerant inlet / outlet) of the heat exchanging portions 60A to 60K where the temperature difference between them becomes the largest. Further, the fin cutting portion 64b may be formed in a plurality of intermittent slit shapes (that is, perforated shapes) instead of a continuous slit shape.

  Thereby, here, the fin cutting part 64b can suppress heat conduction through the fins 64 generated between the main heat exchanging parts 61A to 61K and the adjacent sub heat exchanging parts 62A to 62K. A decrease in the evaporation performance and heat dissipation performance of the container 11 can be suppressed.

<B>
In the said embodiment and the modification A, all the flat pipes 63 which comprise each sub heat exchange part 61A-61K were the same number (two), However, You may make it make the number of the flat pipes 63 different.

  The present invention includes a casing having a suction port formed on a side surface and a blower outlet formed on a top surface, a blower disposed so as to face the blower port, and a heat exchanger disposed below the blower. Widely applicable to exchange units.

2 Outdoor unit (heat exchange unit)
11 Outdoor heat exchanger (heat exchanger)
15 Outdoor fan (blower)
40 Casing 40a, 40b, 40c Suction port 40d Outlet 60A-60K Heat exchange part 61A-61K Main heat exchange part 62A-62K Sub heat exchange part 63 Flat tube 64 Fin 64b Fin cutting part 90 2nd header collection pipe (header collection tube)

JP 2012-163319 A

Claims (5)

A casing (40) having a suction port (40a, 40b, 40c) on the side surface and an air outlet (40d) on the top surface;
A blower (15) that is disposed facing the air outlet in the casing and that takes air into the casing from the air inlet and discharges it from the air outlet.
A heat exchanger (11) disposed below the blower in the casing and performing heat exchange between the refrigerant and the air;
With
The heat exchanger is
An upright header collecting pipe (90);
A plurality of flat tubes (63) arranged vertically and having a passage for the refrigerant formed therein, each end of which is connected to the header collecting tube;
A plurality of fins (64) partitioning into a plurality of ventilation paths through which the air flows between the adjacent flat tubes;
Have
The plurality of flat tubes are divided into a plurality of heat exchange parts (60A to 60K) arranged vertically.
The header collecting pipe has a folded communication space (92A to 92K) corresponding to each of the heat exchanging parts by partitioning the inner space thereof vertically.
Each of the heat exchange units includes a main heat exchange unit (61A to 61K) and a sub heat exchange unit (62A to 62K) connected in series through the folded communication space below the main heat exchange unit. And
According to the wind speed distribution of the air in the heat exchanger, the number of the flat tubes constituting the heat exchange part located in the upper part of the heat exchanger is the heat exchange part located in the lower part of the heat exchanger. Is set to be less than the number of the flat tubes constituting the
Heat exchange unit (2). The number of the flat tubes constituting the main heat exchange part of the heat exchange part located in the upper part of the heat exchanger constitutes the main heat exchange part of the heat exchange part located in the lower part of the heat exchanger. Less than the number of said flat tubes,
The heat exchange unit according to claim 1. The number of the flat tubes constituting the heat exchanger located at the top of the heat exchanger is 0. which is a value obtained by dividing the total number of the flat tubes constituting the heat exchanger by the number of the heat exchangers. 6 to 0.9 times,
The heat exchange unit according to claim 1 or 2. The ratio of the number of the flat tubes constituting the main heat exchange portion to the number of the flat tubes constituting the sub heat exchange portion in each heat exchange portion is 1.5 to 4.5.
The heat exchange unit according to any one of claims 1 to 3. A fin cutting part (64b) for suppressing heat conduction in the vertical direction at the boundary part is formed at a position corresponding to the boundary part between the main heat exchange part and the sub heat exchange part among the plurality of fins. ,
The heat exchange unit according to any one of claims 1 to 4.

Images