Heat exchanger and outdoor unit of refrigeration apparatus

Abstract

An outdoor heat exchanger (20) comprises an upwind heat exchanger (21a) and a downwind heat exchanger (21b). Each of the upwind heat exchanger (21a) and the downwind heat exchanger (21b) is configured from a plurality of flat tubes (52) arranged in the vertical direction and a plurality of fins (54) which are arranged in the extension direction of the flat tubes (52) and to which the flat tubes (52) are joined. The upwind heat exchanger (21a) and the downwind heat exchanger (21b) are arranged in the direction of air flow. A first distance (W1) between the upwind heat exchanger (21a) and the downwind heat exchanger (21b) on a first end (23) side in the extension direction of the upwind heat exchanger (21a) and the downwind heat exchanger (21b) is different from a second distance (W2) between the upwind heat exchanger (21a) and the downwind heat exchanger (21b) on a second end (24) side.

Description

Heat exchanger and outdoor unit of refrigeration apparatus

[0001] The present invention relates to a heat exchanger and an outdoor unit of a refrigeration apparatus.

[0002] A heat exchanger in which flat tubes are inserted into a plurality of notches formed on long sides of fins is known. For example, Patent Document 1 (Japanese Unexamined Patent Application Publication No. 2019-132511) discloses a heat exchanger in which an upwind heat exchange section and a downwind heat exchange section, each constituted by fins into which flat tubes are inserted, are arranged in two rows.

[0003] In the heat exchanger as disclosed in Patent Document 1, a header for connecting a liquid pipe and a gas pipe is disposed at one end side of either the upwind heat exchange section or the downwind heat exchange section. Therefore, it is necessary to arrange the upwind heat exchange section and the downwind heat exchange section with a predetermined distance therebetween so that the headers do not interfere with each other, which poses a problem that the space for accommodating the heat exchanger becomes large.

[0004] The heat exchanger according to a first aspect includes an upwind heat exchange body and a downwind heat exchange body. Each of the upwind heat exchange body and the downwind heat exchange body is constituted by a plurality of flat tubes arranged in a vertical direction, and a plurality of fins arranged in an extending direction of the flat tubes and bonded to the flat tubes. The upwind heat exchange body and the downwind heat exchange body are arranged in an air flow direction. A first distance between the upwind heat exchange body and the downwind heat exchange body at one end side in the extending direction of the upwind heat exchange body and the downwind heat exchange body is different from a second distance between the upwind heat exchange body and the downwind heat exchange body at the other end side.

[0005] In the heat exchanger according to the first aspect, the installation space for the heat exchanger can be reduced.

[0006] The heat exchanger according to a second aspect is the heat exchanger according to the first aspect, further including a connecting header, a first header, and a second header. The connecting header is disposed at the one end side, and connects the flat tubes constituting the upwind heat exchange body and the flat tubes constituting the downwind heat exchange body. The first header is disposed at the other end side of the upwind heat exchange body. The second header is disposed at the other end side of the downwind heat exchange body. The first distance at the one end side is shorter than the second distance at the other end side.

[0007] In the heat exchanger from the second perspective, the first distance between the upwind heat exchanger and the downwind heat exchanger on the side where the connecting header is located is short, which reduces the installation space required for the heat exchanger.

[0008] The heat exchanger of the third aspect is a heat exchanger of the first or second aspect, wherein the upwind heat exchanger and the downwind heat exchanger are bent at least in one place.

[0009] The heat exchanger of the fourth aspect is a heat exchanger of any of the first, second, or third aspects, wherein the fins have an opening formed on one of the pair of long sides that serves as an insertion point for a flattened tube, and a tube insertion section formed from the opening toward the other long side into which the flattened tube is inserted. The fins are arranged such that the tube insertion sections of the fins constituting the upwind heat exchanger and the tube insertion sections of the fins constituting the downwind heat exchanger face each other.

[0010] In the fourth-viewpoint heat exchanger, the side of the upwind heat exchanger where the flat tubes are exposed and the side of the downwind heat exchanger where the flat tubes are exposed face each other. As a result, the flat tubes are not exposed on the upwind side of the heat exchanger, which can delay frost formation on the heat exchanger. In addition, the fin connection section can be placed on the downwind side of the heat exchanger, which can improve the drainage performance of the heat exchanger.

[0011] The heat exchanger in the fifth view is a heat exchanger from either the first view or the fourth view, in which the upwind heat exchanger and the downwind heat exchanger are arranged with a gap between them.

[0012] In the fifth aspect of the heat exchanger, contact between the upwind heat exchanger and the downwind heat exchanger can be suppressed.

[0013] The heat exchanger in the sixth aspect is a heat exchanger in any of the first, second, or fifth aspects, where the first distance is 0 mm or more and 3 mm or less. The second distance is 3 mm or more and 10 mm or less. The second distance is at least twice the first distance.

[0014] The outdoor unit of the refrigeration system in the seventh aspect comprises a heat exchanger according to either the first or sixth aspect.

[0015] This is a schematic diagram of an air conditioning system according to one embodiment of a refrigeration system. This is a perspective view showing the external appearance of the air conditioning outdoor unit. This is a schematic top cross-sectional view illustrating the arrangement of each component of the air conditioning outdoor unit. This is a schematic external perspective view showing the outdoor heat exchanger. This is a schematic configuration diagram showing the flattened tubes and fins that constitute the outdoor heat exchanger. This is a schematic plan view illustrating the shape of the outdoor heat exchanger. This is a schematic plan view illustrating the shape of the outdoor heat exchanger of modified example A.

[0016] (1) Overall configuration diagram 1 of the air conditioning system is a schematic configuration diagram of an air conditioning system 1 according to one embodiment of a refrigeration system.

[0017] The air conditioning system 1 is a device used for heating and cooling a building in which an indoor air conditioning unit 3 is installed, by operating a vapor compression type refrigeration cycle. The air conditioning system 1 is composed of an outdoor air conditioning unit 2, which is the heat source side unit (outdoor unit), and an indoor air conditioning unit 3, which is the user side unit, connected by refrigerant connecting pipes 6 and 7.

[0018] The refrigerant circuit, which is formed by connecting the outdoor unit 2, the indoor unit 3, and the refrigerant connecting pipes 6 and 7, consists of a compressor 91, a four-way switching valve 92, an outdoor heat exchanger 20, an expansion valve 33, an indoor heat exchanger 4, and an accumulator 93, all connected by refrigerant piping. Refrigerant is sealed within this refrigerant circuit, and a refrigeration cycle operation is performed in which the refrigerant is compressed, cooled, depressurized, heated and evaporated, and then compressed again. The refrigerant sealed within the refrigerant circuit is an HFC refrigerant such as R32 or R410A. However, the type of refrigerant is not limited to HFC refrigerants; it may also be a non-azeotropic mixed refrigerant such as R454C. Furthermore, the type of refrigerant may also be an HFO refrigerant such as HFO1234yf, HFO1234ze(E), or a mixture thereof. Additionally, the type of refrigerant may also be a natural refrigerant such as CO2 gas.

[0019] In Figure 1, the air conditioning system 1 has one outdoor unit 2 and one indoor unit 3, but the number of units is merely illustrative. The air conditioning system 1 may have multiple outdoor units 2 or multiple indoor units 3.

[0020] (2) Detailed configuration of the air conditioning system (2-1) Indoor air conditioning unit The indoor air conditioning unit 3 is installed on the wall of a room by being mounted on the wall, or by being embedded in or suspended from the ceiling of a room in a building, etc. The indoor air conditioning unit 3 has an indoor heat exchanger 4 and an indoor fan 5. The indoor heat exchanger 4 is a cross-fin type fin-and-tube heat exchanger composed of, for example, heat transfer tubes and a large number of fins. The indoor heat exchanger 4 is a heat exchanger that functions as a refrigerant evaporator to cool the indoor air during cooling operation and as a refrigerant condenser to heat the indoor air during heating operation.

[0021] (2-2) Air Conditioning Outdoor Unit The air conditioning outdoor unit 2 is installed outside a building or the like and is connected to the air conditioning indoor unit 3 via refrigerant connecting pipes 6 and 7. As shown in Figures 2 and 3, the air conditioning outdoor unit 2 has a roughly rectangular parallelepiped unit casing 10.

[0022] In the following explanation, expressions such as "up," "down," "left," "right," "front," "back," "front view," and "rear view" may be used to describe directions and positional relationships. Unless otherwise specified, the directions indicated by these expressions follow the directions of the arrows shown in the drawings.

[0023] As shown in Figure 3, the air conditioning outdoor unit 2 has a structure (a so-called trunk-type structure) in which the internal space of the unit casing 10 is divided into two by a partition plate 18 extending vertically to form a blower room S1 and a machine room S2. The air conditioning outdoor unit 2 has an outdoor heat exchanger 20 and an outdoor fan 95 located in the blower room S1 of the unit casing 10. The air conditioning outdoor unit 2 also has a compressor 91, a four-way switching valve 92, an accumulator 93, an expansion valve 33, gas refrigerant piping 31, and liquid refrigerant piping 32 located in the machine room S2 of the unit casing 10.

[0024] The unit casing 10 comprises a bottom plate 12, a top plate 11, a side plate 13 on the blower room side, a side plate 14 on the machine room side, a front plate 15 on the blower room side, and a front plate 16 on the machine room side, forming the enclosure.

[0025] The air conditioning outdoor unit 2 is configured to draw in outdoor air from the back and a portion of the sides of the unit casing 10 into the fan chamber S1 inside the unit casing 10, and to blow out the drawn-in outdoor air from the front of the unit casing 10. Specifically, an intake port 10a, an intake port 10b, and an outlet port 10c are formed in the fan chamber S1 inside the unit casing 10. The entire intake ports 10a and 10b extend from the rear end of the side plate 13 on the fan chamber side to the end of the side plate 14 on the machine chamber side that is on the fan chamber S1 side. The outlet port 10c is provided on the front plate 15 on the fan chamber side, and its front side is covered by a fan grille 15a.

[0026] The compressor 91 is a sealed compressor driven by, for example, a compressor motor, and is configured to allow its operating capacity to be changed by inverter control. By changing the operating capacity in this way, it is possible to respond to fluctuations in the air conditioning load.

[0027] The four-way diverter valve 92 is a mechanism for switching the direction of refrigerant flow. During cooling operation, the four-way diverter valve 92 connects the refrigerant piping on the discharge side of the compressor 91 to the gas refrigerant piping 31 extending from one end (gas side end) of the outdoor heat exchanger 20, and also connects the refrigerant communication piping 7 of the gas refrigerant to the refrigerant piping on the suction side of the compressor 91 via the accumulator 93 (see the solid line of the four-way diverter valve 92 in Figure 1). During heating operation, the four-way diverter valve 92 connects the refrigerant piping on the discharge side of the compressor 91 to the gas refrigerant communication piping 7, and also connects the suction side of the compressor 91 to the gas refrigerant piping 31 extending from one end (gas side end) of the outdoor heat exchanger 20 via the accumulator 93 (see the dashed line of the four-way diverter valve 92 in Figure 1).

[0028] The outdoor heat exchanger 20 is an example of a heat exchanger. The outdoor heat exchanger 20 is positioned vertically in the fan chamber S1, facing the intake ports 10a and 10b. A gas refrigerant pipe 31 extends from one end (the gas side end) of the outdoor heat exchanger 20 to connect to a four-way switching valve 92. A liquid refrigerant pipe 32 extends from the other end (the liquid side end) of the outdoor heat exchanger 20 to connect to an expansion valve 33.

[0029] The accumulator 93 is connected between the four-way switching valve 92 and the compressor 91. The accumulator 93 has a gas-liquid separation function that separates the refrigerant into a gas phase and a liquid phase. The refrigerant flowing into the accumulator 93 is separated into a liquid phase and a gas phase, and the gas phase refrigerant that collects in the upper space is supplied to the compressor 91.

[0030] The expansion valve 33 is a mechanism for reducing the refrigerant pressure in the refrigerant circuit and is an electrically operated valve with adjustable opening. The expansion valve 33 is installed between the outdoor heat exchanger 20 and the liquid refrigerant refrigerant communication pipe 6 to adjust the refrigerant pressure and flow rate, and has the function of expanding the refrigerant during both cooling and heating operations.

[0031] The outdoor fan 95 supplies outdoor air to the outdoor heat exchanger 20 for heat exchange with the refrigerant flowing through the outdoor heat exchanger 20. The outdoor fan 95 is positioned in the fan chamber S1 facing the outdoor heat exchanger 20. The outdoor fan 95 draws outdoor air into the unit casing 10 from the rear side, allows heat exchange to occur between the refrigerant and the outdoor air in the outdoor heat exchanger 20, and then discharges the heat-exchanged air outside the unit casing 10 from the front side. This outdoor fan 95 is a fan capable of changing the airflow rate of the outdoor air supplied to the outdoor heat exchanger 20, and is, for example, a propeller fan driven by a motor such as a DC fan motor.

[0032] (3) Operation of the air conditioning system (3-1) Cooling operation During cooling operation, the four-way switching valve 92 is in the state shown by the solid line in Figure 1. Specifically, the discharge side of the compressor 91 is connected to the gas side of the outdoor heat exchanger 20 via the gas refrigerant piping 31, and the suction side of the compressor 91 is connected to the gas side of the indoor heat exchanger 4 via the refrigerant connecting piping 7.

[0033] In this refrigerant circuit configuration, when the compressor 91, outdoor fan 95, and indoor fan 5 are operated, the low-pressure gaseous refrigerant is compressed by the compressor 91 to become high-pressure gaseous refrigerant. This high-pressure gaseous refrigerant is sent to the outdoor heat exchanger 20 via the four-way switching valve 92. Thereafter, the high-pressure gaseous refrigerant exchanges heat with the outdoor air supplied by the outdoor fan 95 in the outdoor heat exchanger 20 and condenses to become high-pressure liquid refrigerant. The high-pressure liquid refrigerant is sent from the outdoor heat exchanger 20 to the expansion valve 33. The refrigerant, which is reduced in pressure by the expansion valve 33 to become a low-pressure gas-liquid two-phase state, is sent to the indoor heat exchanger 4, where it exchanges heat with the indoor air and evaporates to become low-pressure gaseous refrigerant. This low-pressure gaseous refrigerant is sent to the air conditioning outdoor unit 2 via the refrigerant communication pipe 7 and is again drawn into the compressor 91. In this way, during cooling operation, the air conditioning system 1 causes the outdoor heat exchanger 20 to function as a condenser for the refrigerant compressed in the compressor 91, and the indoor heat exchanger 4 to function as an evaporator for the refrigerant condensed in the outdoor heat exchanger 20.

[0034] (3-2) Heating Operation During heating operation, the four-way switching valve 92 is in the state shown by the dashed line in Figure 1. Specifically, the discharge side of the compressor 91 is connected to the gas side of the indoor heat exchanger 4 via the refrigerant communication pipe 7, and the suction side of the compressor 91 is connected to the gas side of the outdoor heat exchanger 20 via the gas refrigerant pipe 31.

[0035] In this refrigerant circuit configuration, when the compressor 91, outdoor fan 95, and indoor fan 5 are operated, the low-pressure gaseous refrigerant is drawn into the compressor 91 and compressed to become high-pressure gaseous refrigerant. This high-pressure gaseous refrigerant is sent to the air conditioning indoor unit 3 via the four-way switching valve 92 and the refrigerant communication piping 7. The high-pressure gaseous refrigerant sent to the air conditioning indoor unit 3 condenses in the indoor heat exchanger 4 through heat exchange with the indoor air to become high-pressure liquid refrigerant. The high-pressure liquid refrigerant is sent from the indoor heat exchanger 4 to the expansion valve 33. The refrigerant, which is reduced in pressure by the expansion valve 33 to become a low-pressure gas-liquid two-phase state, is sent to the outdoor heat exchanger 20, where it evaporates through heat exchange with the outdoor air to become low-pressure gaseous refrigerant. This low-pressure gaseous refrigerant is drawn into the compressor 91 again via the four-way switching valve 92. In this way, during heating operation, the air conditioning system 1 causes the indoor heat exchanger 4 to function as a condenser for the refrigerant compressed in the compressor 91, and the outdoor heat exchanger 20 to function as an evaporator for the refrigerant condensed in the indoor heat exchanger 4.

[0036] (4) Detailed Configuration of the Outdoor Heat Exchanger The outdoor heat exchanger 20 is a heat exchanger that performs heat exchange between the refrigerant and the outdoor air. The outdoor heat exchanger 20 functions as a condenser during cooling operation and as an evaporator during heating operation. Figure 4 is a schematic external perspective view showing the outdoor heat exchanger 20. Figure 5 is a schematic configuration diagram showing the flattened tubes 52 and fins 54 that constitute the outdoor heat exchanger 20. Figure 6 is a schematic plan view illustrating the shape of the outdoor heat exchanger 20. Note that Figures 4 to 6 are schematic diagrams to illustrate the flattened tubes 52 and fins 54 that constitute the outdoor heat exchanger 20 and the shape of the outdoor heat exchanger 20, and do not accurately represent the structure and shape of the outdoor heat exchanger 20, etc.

[0037] The outdoor heat exchanger 20 mainly comprises multiple rows (two rows in this case) of heat exchange sections 21 that perform heat exchange between outdoor air and refrigerant, a first header 70, a second header 80, and a connecting header 90. The heat exchange section 21 has an upwind heat exchanger 21a and a downwind heat exchanger 21b arranged in the direction of the airflow generated by the outdoor fan 95. Specifically, the upwind heat exchanger 21a is located on the upwind side, and the downwind heat exchanger 21b is located on the downwind side. The connecting header 90 is provided on one end (hereinafter referred to as the first end 23) in the extension direction of the heat exchange section 21 (upwind heat exchanger 21a and downwind heat exchanger 21b). The first header 70 and the second header 80 are provided on the other end (hereinafter referred to as the second end 24) in the extension direction of the heat exchange section 21 (upwind heat exchanger 21a and downwind heat exchanger 21b).

[0038] (4-1) The first header 70 is a vertically elongated, hollow, cylindrical member with its upper and lower ends closed. The first header 70 is erected on the second end 24 side of the windward heat exchanger 21a. As shown in Figure 3, the first header 70 is located at the right rear of the air conditioning outdoor unit 2.

[0039] The second end 24 side of each flattened tube 52 of the upwind heat exchanger 21a is connected to the first header 70, and the internal space of the first header 70 is in communication with each flattened tube 52 of the upwind heat exchanger 21a. The first header 70 has the function of supporting the flattened tubes 52, guiding the refrigerant to the inlet 51 of the flattened tubes 52, and collecting the refrigerant coming out of the inlet 51 of the flattened tubes 52. The first header 70 is connected to the liquid refrigerant piping 32.

[0040] (4-2) The second header 80 is a vertically elongated, hollow, cylindrical member with its upper and lower ends closed. The second header 80 is erected on the second end 24 side of the downwind heat exchanger 21b. As shown in Figure 3, the second header 80 is located on the right rear side of the air conditioning outdoor unit 2. The second header 80 is located in front of and to the right of the first header 70. In other words, the first header 70 and the second header 80 are arranged in a staggered pattern in a plan view.

[0041] The second end 24 side of each flat tube 52 of the leeward heat exchanger 21b is connected to the second header 80, and the internal space of the second header 80 communicates with each flat tube 52 of the leeward heat exchanger 21b. The second header 80 has a function of supporting the flat tubes 52, a function of guiding a refrigerant to the inlet 51 of the flat tubes 52, and a function of collecting the refrigerant discharged from the inlet 51 of the flat tubes 52. The second header 80 is connected to a gas refrigerant pipe 31.

[0042] (4-3) Connection header The connection header 90 is a vertically elongated hollow cylindrical member with closed upper and lower ends. The connection header 90 is provided upright on the first end 23 side of the heat exchange section 21. In other words, the connection header 90 is provided on the side of the windward heat exchanger 21a opposite to the side where the first header 70 is provided, and on the side of the leeward heat exchanger 21b opposite to the side where the second header 80 is provided. As shown in FIG. 3, the connection header 90 is disposed at the left front portion of the air conditioning outdoor unit 2.

[0043] The first end 23 side of each flat tube 52 of the windward heat exchanger 21a and the first end 23 side of each flat tube 52 of the leeward heat exchanger 21b are connected to the connection header 90. In other words, the internal space of the second header 80 communicates with each flat tube 52 of the windward heat exchanger 21a and each flat tube 52 of the leeward heat exchanger 21b.

[0044] The connection header 90 has a function of connecting the flat tubes 52 of the windward heat exchanger 21a and the flat tubes 52 of the leeward heat exchanger 21b. When the outdoor heat exchanger 20 functions as a refrigerant condenser, the connection header 90 turns the refrigerant back from the leeward-side flat tubes 52 to the windward-side flat tubes 52. When the outdoor heat exchanger 20 functions as a refrigerant evaporator, the connection header 90 turns the refrigerant back from the windward-side flat tubes 52 to the leeward-side flat tubes 52.

[0045] (4-4) Heat Exchange Part The heat exchange part 21 comprises a windward heat exchanger 21a provided along an edge of a windward portion in the flow direction of air generated by the outdoor fan 95 (flow directed from the back surface and left side surface of the housing toward the fan grille 15a on the front surface of the housing), and a leeward heat exchanger 21b provided along an edge of the leeward side. The windward heat exchanger 21a and the leeward heat exchanger 21b are arranged in two rows along the air flow direction. Further, the windward heat exchanger 21a and the leeward heat exchanger 21b are arranged with a gap therebetween.

[0046] The windward heat exchanger 21a has a plurality of flat tubes 52 extending along the edge of the windward side and arranged in the vertical direction, and fins 54 fixed to the flat tubes 52. Similarly, the leeward heat exchanger 21b also has a plurality of flat tubes 52 extending along the edge of the leeward side and arranged in the vertical direction, and fins 54 fixed to the flat tubes 52.

[0047] The flat tubes 52 function as heat transfer tubes, and transfer heat moving between the fins 54 and outdoor air to the refrigerant flowing inside the flat tubes 52. The flat tube 52 is a flat multi-hole tube having upper and lower flat portions 50 serving as heat transfer surfaces and a plurality of flow passages 51 through which the refrigerant flows (see FIG. 5). In each of the windward heat exchanger 21a and the leeward heat exchanger 21b, the plurality of flat tubes 52 are arranged at predetermined intervals in the vertical direction.

[0048] One end (the first end 23 side) of the flat tube 52 of the windward heat exchanger 21a is connected to the connection header 90. The other end (the second end 24 side) of the flat tube 52 of the windward heat exchanger 21a is connected to the first header 70. Further, one end (the first end 23 side) of the flat tube 52 of the leeward heat exchanger 21b is connected to the connection header 90. The other end (the second end 24 side) of the flat tube 52 of the leeward heat exchanger 21b is connected to the second header 80.

[0049] The fins 54 are components that increase the heat transfer area of ​​the heat exchange section 21. The fins 54 divide the space between adjacent flat pipes 52 in the vertical direction into multiple air passages through which air flows. Multiple flat pipes 52 are joined to the fins 54. In both the upwind heat exchanger 21a and the downwind heat exchanger 21b, the multiple fins 54 are arranged in a line along the direction in which the flat pipes 52 extend. As shown in Figure 5, the fins 54 are flat plate members. Hereinafter, the multiple fins 54 constituting the upwind heat exchanger 21a will be called the upwind fins 54a, and the multiple fins 54 constituting the downwind heat exchanger 21b will be called the downwind fins 54b.

[0050] Each fin 54 mainly has a plurality of openings 60, a plurality of pipe insertion portions 61, and a communication portion 57. The openings 60 are formed on one of the pair of long sides of the fin 54 and serve as insertion points for the flat pipe 52. The pipe insertion portions 61 are formed extending from the openings 60 toward the other long side of the fin 54 and are the portions into which the flat pipe 52 is inserted. In other words, the pipe insertion portions 61 are notches for inserting the flat pipe 52 that extend horizontally. Each fin 54 has a plurality of pipe insertion portions 61 arranged in the vertical direction. The shape of the pipe insertion portions 61 is approximately the same as the outer cross-sectional shape of the flat pipe 52. The flat pipe 52 is fixed to the pipe insertion portions 61 by brazing or the like when inserted. The communication portion 57 is part of the fin 54.

[0051] The flattened tube 52 of the upwind heat exchanger 21a is inserted into the tube insertion section 61 of the upwind fin 54a. Similarly, the flattened tube 52 of the downwind heat exchanger 21b is inserted into the tube insertion section 61 of the downwind fin 54b. The upwind fin 54a and the downwind fin 54b are positioned with a gap between them. Furthermore, the tube insertion section 61 of the upwind fin 54a and the tube insertion section 61 of the downwind fin 54b are positioned facing each other. In other words, the opening 60 of the upwind fin 54a and the opening 60 of the downwind fin 54b are positioned facing each other. To put it another way, the side of the upwind heat exchanger 21a where the flattened tube 52 is exposed and the side of the downwind heat exchanger 21b where the flattened tube 52 is exposed are positioned facing each other. In the upwind fin 54a, the communication portion 57 is a portion that extends continuously in the vertical direction further upwind than the upwind end of the flattened pipe 52 of the upwind heat exchanger 21a. In the downwind fin 54b, the communication portion 57 is a portion that extends continuously in the vertical direction further downwind than the downwind end of the flattened pipe 52 of the downwind heat exchanger 21b.

[0052] As shown in Figure 6, the heat exchange section 21 is bent to form a roughly L-shape in plan view. In other words, the upwind heat exchanger 21a and the downwind heat exchanger 21b are bent at one point. Specifically, the heat exchange section 21 has one bent section 25. The flattened tubes 52 of the upwind heat exchanger 21a and the downwind heat exchanger 21b are each bent at approximately 90 degrees at the bent section 25.

[0053] In the upwind heat exchanger 21a, the portion extending linearly from the connecting header 90 toward the bent portion 25 is designated as the first upwind portion 26a, and the portion extending linearly from the first header 70 toward the bent portion 25 is designated as the second upwind portion 27a. In the downwind heat exchanger 21b, the portion extending linearly from the connecting header 90 toward the bent portion 25 is designated as the first downwind portion 26b, and the portion extending linearly from the second header 80 toward the bent portion 25 is designated as the second downwind portion 27b. The first upwind portion 26a and the first downwind portion 26b are arranged approximately parallel to each other. The second upwind portion 27a and the second downwind portion 27b are also arranged approximately parallel to each other.

[0054] Here, in a plan view, the distance between the upwind heat exchanger 21a and the downwind heat exchanger 21b on the first end 23 side is called the first distance W1. Specifically, the first distance W1 is the horizontal distance between the first upwind section 26a and the first downwind section 26b in a direction perpendicular to the extension direction of the first upwind section 26a and the first downwind section 26b in a plan view. Also, in a plan view, the distance between the upwind heat exchanger 21a and the downwind heat exchanger 21b on the second end 24 side is called the second distance W2. Specifically, the second distance W2 is the horizontal distance between the second upwind section 27a and the second downwind section 27b in a direction perpendicular to the extension direction of the second upwind section 27a and the second downwind section 27b in a plan view.

[0055] The upwind heat exchanger 21a and the downwind heat exchanger 21b are arranged such that the first distance W1 is shorter than the second distance W2. In other words, the first distance W1 and the second distance W2 are different. Specifically, the second distance W2 is more than twice the first distance W1. Also, the length of the first distance W1 is 0 mm or more and 3 mm or less. The length of the second distance W2 is 3 mm or more and 10 mm or less.

[0056] (5) Characteristics In a heat exchanger in which an upwind heat exchange section and a downwind heat exchange section are arranged in two rows, each composed of fins into which flattened tubes are inserted, a header for connecting liquid piping and gas piping is placed on one end of the upwind heat exchange section and the downwind heat exchange section. For this reason, the upwind heat exchange section and the downwind heat exchange section must be placed at a predetermined distance apart to prevent the headers from interfering with each other, which presents the challenge of requiring a larger space to house the heat exchanger.

[0057] (5-1) The outdoor heat exchanger 20 of this embodiment includes an upwind heat exchanger 21a and a downwind heat exchanger 21b. The upwind heat exchanger 21a and the downwind heat exchanger 21b are each composed of a plurality of flat pipes 52 arranged in the vertical direction and a plurality of fins 54 arranged in the direction of extension of the flat pipes 52 and to which the flat pipes 52 are joined. The upwind heat exchanger 21a and the downwind heat exchanger 21b are arranged in the direction of airflow. The first distance W1 between the upwind heat exchanger 21a and the downwind heat exchanger 21b at one end (first end 23) in the direction of extension of the upwind heat exchanger 21a and the downwind heat exchanger 21b is different from the second distance W2 between the upwind heat exchanger 21a and the downwind heat exchanger 21b at the other end (second end 24).

[0058] In the outdoor heat exchanger 20, the first distance W1 and the second distance W2 are different, which prevents either the first distance W1 or the second distance W2 from becoming unnecessarily large. As a result, the installation space required for the outdoor heat exchanger 20 can be reduced.

[0059] (5-2) The outdoor heat exchanger 20 of this embodiment further comprises a connecting header 90, a first header 70, and a second header 80. The connecting header 90 is located on one end (first end 23) and connects the flat pipe 52 constituting the upwind heat exchanger 21a and the flat pipe 52 constituting the downwind heat exchanger 21b. The first header 70 is located on the other end (second end 24) side of the upwind heat exchanger 21a. The second header 80 is located on the other end (second end 24) side of the downwind heat exchanger 21b. The first distance W1 on one end is shorter than the second distance W2 on the other end.

[0060] At the second end 24 side of the heat exchange section 21, the dimensions of the first header 70 in a first direction perpendicular to the extension direction of the flattened pipe 52 extending linearly from the first header 70 are larger than the dimensions of the flattened pipe 52 in the first direction. Also, the dimensions of the second header 80 in the first direction are larger than the dimensions of the flattened pipe 52 in the first direction. Therefore, at the second end 24 side of the heat exchange section 21, it is necessary to consider interference between the headers. On the other hand, at the first end 23 side of the heat exchange section 21, the flattened pipes 52 of the upwind heat exchanger 21a and the downwind heat exchanger 21b are connected to the connecting header 90. Therefore, at the first end 23 side of the heat exchange section 21, it is not necessary to consider interference between the headers. In other words, the required distance between the upwind heat exchanger 21a and the downwind heat exchanger 21b differs between the first end 23 side and the second end 24 side of the heat exchange section 21.

[0061] In this outdoor heat exchanger 20, by making the first distance W1 between the upwind heat exchanger 21a and the downwind heat exchanger 21b at the first end 23 side where the connecting header 90 is located shorter than the second distance W2, the installation space required for the outdoor heat exchanger 20 can be reduced. Furthermore, by making the second distance W2 between the upwind heat exchanger 21a and the downwind heat exchanger 21b at the second end 24 side where the first header 70 and the second header 80 are located longer than the first distance W1, interference between the first header 70 and the second header 80 can be suppressed.

[0062] (5-3) In this embodiment, the outdoor heat exchanger 20 has an upwind heat exchanger 21a and a downwind heat exchanger 21b that are bent at least at one location.

[0063] (5-4) In this embodiment, the outdoor heat exchanger 20 has fins 54 that have an opening 60 formed on one of the pair of long sides which serves as an insertion point for a flat pipe 52, and a pipe insertion portion 61 formed from the opening 60 toward the other long side into which the flat pipe 52 is inserted. The fins 54 are arranged such that the pipe insertion portion 61 of the fin 54 constituting the upwind heat exchanger 21a (upwind fin 54a) and the pipe insertion portion 61 of the fin 54 constituting the downwind heat exchanger 21b (downwind fin 54b) face each other.

[0064] In this outdoor heat exchanger 20, the side of the upwind heat exchanger 21a where the flat pipe 52 is exposed and the side of the downwind heat exchanger 21b where the flat pipe 52 is exposed are arranged to face each other. As a result, the flat pipe 52 is not exposed on the upwind side of the outdoor heat exchanger 20, which delays frost formation on the outdoor heat exchanger 20. In addition, the connecting portion 57 of the fins 54 can be placed on the downwind side of the outdoor heat exchanger 20, which improves the drainage performance of the outdoor heat exchanger 20.

[0065] Here, the distance D1 from the leeward end of the flat tube 52 of the upwind heat exchanger 21a to the leeward end of the upwind fin 54a is shorter than the distance D2 from the upwind end of the flat tube 52 of the upwind heat exchanger 21a to the upwind end of the upwind fin 54a (see Figure 5). The distance D3 from the upwind end of the flat tube 52 of the downwind heat exchanger 21b to the upwind end of the downwind fin 54b is shorter than the distance D4 from the downwind end of the flat tube 52 of the downwind heat exchanger 21b to the leeward end of the downwind fin 54b (see Figure 5). Therefore, when the pipe insertion portions 61 of the upwind fin 54a and the downwind fin 54b are arranged facing each other, the distance between the flat pipe 52 of the upwind heat exchanger 21a and the flat pipe 52 of the downwind heat exchanger 21b becomes shorter compared to when the pipe insertion portions 61 of the upwind fin 54a and the downwind fin 54b are arranged facing the same direction. As a result, the distance between the first header 70 and the second header 80 also becomes shorter. However, because the first distance W1 and the second distance W2 are different in this outdoor heat exchanger 20, interference between the first header 70 and the second header 80 can be suppressed.

[0066] (5-5) In this embodiment, the outdoor heat exchanger 20 is arranged with a gap between the upwind heat exchanger 21a and the downwind heat exchanger 21b. This prevents contact between the upwind heat exchanger 21a and the downwind heat exchanger 21b.

[0067] (5-6) In this embodiment, the outdoor heat exchanger 20 has a first distance W1 of 0 mm or more and 3 mm or less. The second distance W2 is 3 mm or more and 10 mm or less. The second distance W2 is twice the first distance W1 or more.

[0068] (5-7) An example of an outdoor unit of the refrigeration system of this embodiment is the air conditioning outdoor unit 2 of the air conditioning system 1, which is equipped with the outdoor heat exchanger 20 of this embodiment.

[0069] (6) Modifications The above embodiments can be modified as appropriate, for example, as shown in the following modifications. Each modification may be combined with other modifications as appropriate, within the limits of what is not contradictory.

[0070] (6-1) Modification A In the above embodiment, the upwind heat exchanger 21a and the downwind heat exchanger 21b are bent at one point, but are not limited to this. For example, the upwind heat exchanger 21a and the downwind heat exchanger 21b may be bent at two points to form a substantially U-shape. Also, the upwind heat exchanger 21a and the downwind heat exchanger 21b may be bent at three or more points.

[0071] Figure 7 is a schematic plan view illustrating the shape of the outdoor heat exchanger 20, which is bent at two points to form a roughly U-shape. The heat exchange section 21 has two bent sections 25a and 25b. The flattened tubes 52 of the upwind heat exchanger 21a and the downwind heat exchanger 21b are bent at approximately 90 degrees at the bent sections 25a and 25b, respectively.

[0072] In the upwind heat exchanger 21a, the portion extending linearly from the connecting header 90 toward the bent portion 25a is designated as the first upwind section 26a. In the upwind heat exchanger 21a, the portion extending linearly from the first header 70 toward the bent portion 25b is designated as the second upwind section 27a. In the upwind heat exchanger 21a, the portion extending linearly from the bent portion 25a toward the bent portion 25b is designated as the third upwind section 28a. Furthermore, in the downwind heat exchanger 21b, the portion extending linearly from the connecting header 90 toward the bent portion 25a is designated as the first downwind section 26b. In the downwind heat exchanger 21b, the portion extending linearly from the second header 80 toward the bent portion 25b is designated as the second downwind section 27b. In the downwind heat exchanger 21b, the portion extending linearly from the bent portion 25a toward the bent portion 25b is designated as the third downwind section 28b. The first upwind section 26a and the first downwind section 26b are arranged approximately parallel to each other. The second upwind section 27a and the second downwind section 27b are also arranged approximately parallel to each other. Furthermore, the third upwind section 28a and the third downwind section 28b are arranged approximately parallel to each other.

[0073] Here, in a plan view, the distance between the upwind heat exchanger 21a and the downwind heat exchanger 21b on the first end 23 side is called the first distance W1. Specifically, the first distance W1 is the horizontal distance between the first upwind section 26a and the first downwind section 26b in a direction perpendicular to the extension direction of the first upwind section 26a and the first downwind section 26b in a plan view. Also, in a plan view, the distance between the upwind heat exchanger 21a and the downwind heat exchanger 21b on the second end 24 side is called the second distance W2. Specifically, the second distance W2 is the horizontal distance between the second upwind section 27a and the second downwind section 27b in a direction perpendicular to the extension direction of the second upwind section 27a and the second downwind section 27b in a plan view. Also, in a plan view, the distance between the third upwind section 28a and the third downwind section 28b is called the third distance W3. Specifically, the third distance W3 is the horizontal distance between the third windward-upward-upward-upward-downward-up

[0074] The first distance W1 and the third distance W3 are approximately the same, but are not limited to this, and the first distance W1 and the third distance W3 may be different. The upwind heat exchanger 21a and the downwind heat exchanger 21b are arranged such that the first distance W1 is shorter than the second distance W2. In other words, the first distance W1 and the second distance W2 are different. Specifically, the second distance W2 is at least twice the length of the first distance W1. Also, the length of the first distance W1 is 0 mm or more and 3 mm or less. The length of the second distance W2 is 3 mm or more and 10 mm or less.

[0075] (6-2) Modification B In the above embodiment, the refrigeration system was described using the air conditioning system 1 as an example, but the features of the above embodiment may be applied to other types of refrigeration systems. For example, the features of the above embodiment may be applied to a hot water supply system as an example of a refrigeration system.

[0076] (6-3) Modification C In the above embodiment, the air conditioning outdoor unit 2 is a trunk-type horizontal-blowing unit, which draws in outdoor air from the back and a part of the sides of the unit casing 10 and blows out air from the front of the unit casing 10. However, the air conditioning outdoor unit 2 is not limited to the horizontal-blowing type, and may be an upward-blowing unit, for example.

[0077] While embodiments and variations of this disclosure have been described above, it should be understood that various changes in form and details are possible without departing from the spirit and scope of this disclosure as described in the claims.

[0078] 1 Air conditioning system (refrigeration system) 2 Air conditioning outdoor unit (outdoor unit) 20 Outdoor heat exchanger (heat exchanger) 21 Heat exchange section 21a Upwind heat exchanger 21b Downwind heat exchanger 23 First end (one end) 24 Second end (the other end) 52 Flat pipe 54 Fin 54a Upwind fin (fin) 54b Downwind fin (fin) 60 Opening 61 Pipe insertion section 70 First header 80 Second header 90 Connecting header W1 First distance W2 Second distance

[0079] Japanese Patent Publication No. 2019-132511

Claims

1. A heat exchanger (20) comprising a windward heat exchanger (21a) and a leeward heat exchanger (21b), each composed of a plurality of flattened tubes (52) arranged vertically and a plurality of fins (54, 54a, 54b) arranged in the direction of extension of the flattened tubes and joined to the flattened tubes, and arranged in the direction of airflow, wherein the first distance (W1) between the windward heat exchanger and the leeward heat exchanger at one end (23) in the direction of extension of the windward heat exchanger and the leeward heat exchanger and the second distance (W2) between the windward heat exchanger and the leeward heat exchanger at the other end (24) are different.

2. The heat exchanger according to claim 1, further comprising: a connecting header (90) disposed on one end and connecting the flat tube constituting the upwind heat exchanger and the flat tube constituting the downwind heat exchanger; a first header (70) disposed on the other end of the upwind heat exchanger; and a second header (80) disposed on the other end of the downwind heat exchanger, wherein the first distance on one end is shorter than the second distance on the other end.

3. The heat exchanger according to claim 1 or 2, wherein the upwind heat exchanger and the downwind heat exchanger are bent at least at one location.

4. The heat exchanger according to any one of claims 1 to 3, wherein the fin has an opening (60) formed on one of a pair of long sides which serves as an insertion point for the flattened tube, and a tube insertion portion (61) formed extending from the opening toward the other long side into which the flattened tube is inserted, and the tube insertion portion of the fin constituting the upwind heat exchanger and the tube insertion portion of the fin constituting the downwind heat exchanger are arranged to face each other.

5. The heat exchanger according to any one of claims 1 to 4, wherein the upwind heat exchanger and the downwind heat exchanger are arranged with a gap between them.

6. The heat exchanger according to any one of claims 1 to 5, wherein the first distance is 0 mm or more and 3 mm or less, the second distance is 3 mm or more and 10 mm or less, and the second distance is at least twice the first distance.

7. An outdoor unit (2) of a refrigeration system (1) comprising a heat exchanger (20) according to any one of claims 1 to 6.

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