Gas heat pump type air conditioning system and heat exchanger for outdoor unit

Abstract

To provide a gas heat pump type air conditioning system and a heat exchanger for an outdoor unit capable of defrosting frost generated on a corrugated fin in heating operation, and hardly impairing the appearance.SOLUTION: A gas heat pump type air conditioning system includes an outdoor unit heat exchanger, a compressor, a drive source for driving the compressor, and a radiator for cooling the drive source. The heat exchanger for an outdoor unit includes a plurality of flat multi-hole tubes and a plurality of corrugated fins. The plurality of corrugated fins include a plurality of first corrugated fins that protrude toward the downstream side in the air flow direction with respect to the flat multi-hole tubes, and a plurality of second corrugated fins that do not protrude toward the upstream side or the downstream side in the air flow direction with respect to the flat multi-hole tubes. The radiator is adjacent to the plurality of first corrugated fins on the downstream side in the air flow direction.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a gas heat pump air conditioning system and a heat exchanger for an outdoor unit. [Background technology]

[0002] Patent Document 1 discloses a heat exchanger having a plurality of flat heat transfer tubes with flat cross sections and a plurality of corrugated fins arranged in a zigzag pattern in the vertical direction between opposing flat surfaces. According to Patent Document 1, the corrugated fins protrude upstream in the airflow direction beyond the ends of the flat surfaces of the flat heat transfer tubes. The corrugated fins also have drainage holes provided at positions corresponding to the central portions of the flat surfaces of the flat heat transfer tubes, and a plurality of slits and louvers on the upstream and downstream sides of the drainage holes in the airflow direction. This improves the drainage of water generated on the corrugated fins, thereby improving heat exchange efficiency. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6400257 Summary of the Invention [Problem to be solved by the invention]

[0004] The heat exchanger described in Patent Document 1 takes into consideration the drainage of water that forms on the corrugated fins during heating operation, but does not take into consideration the defrosting of water that has frosted on the corrugated fins. In addition, the corrugated fins that protrude in the direction of ventilation are prone to deformation due to contact with other parts during assembly of the heat exchanger or an air conditioner equipped with the heat exchanger, which can impair the aesthetic appearance.

[0005] To provide a gas heat pump type air conditioning system and a heat exchanger for an outdoor unit that can defrost frost formed on corrugated fins during heating operation and that do not impair the aesthetic appearance. [Means for solving the problem]

[0006] The present disclosure provides: A plurality of flat multi-hole pipes extending in a first direction perpendicular to the ventilation direction and the ventilation direction and arranged side by side in a second direction perpendicular to the ventilation direction and the first direction; a plurality of corrugated fins arranged side by side in the second direction between the plurality of flat multi-hole pipes and extending in a wavy manner in the first direction; and a heat exchanger for an outdoor unit, wherein the corrugated fins are a plurality of first corrugated fins provided on one side of the first direction and protruding downstream in the ventilation direction relative to the plurality of flat multi-hole pipes; a plurality of second corrugated fins provided on the other side of the first direction and not protruding toward the upstream side or downstream side in the ventilation direction relative to the plurality of flat multi-hole pipes; It has A compressor; a drive source that drives the compressor; a radiator adjacent to the plurality of first corrugated fins on the downstream side in the ventilation direction and configured to cool the driving source; A gas heat pump air conditioning system is provided.

[0007] In the gas heat pump air conditioning system according to the present disclosure, the first corrugated fins protrude downstream in the direction of airflow relative to the flat multi-hole pipes, and the radiator is adjacent to the first corrugated fins downstream, so that frost formed on the first corrugated fins can be efficiently defrosted using heat from the radiator. Furthermore, the second corrugated fins do not protrude downstream or upstream in the direction of airflow relative to the flat multi-hole pipes, so that deformation of the corrugated fins due to contact with other components at the position where the second corrugated fins are provided can be suppressed, and the aesthetic appearance of the outdoor unit heat exchanger can be maintained. [Brief explanation of the drawings]

[0008] [Figure 1]1 is a refrigerant circuit diagram of a gas heat pump air conditioning system according to an embodiment of the present invention. [Figure 2] 1 is a perspective view of an outdoor unit heat exchanger and a radiator according to an embodiment of the present invention; [Figure 3] FIG. 2 is a side view of the outdoor unit heat exchanger and the radiator according to the embodiment. [Figure 4] 3 is an enlarged perspective view of a part of the flat multi-hole pipe and the corrugated fin of FIG. 2. FIG. [Figure 5] 3 is a top view of a flat multi-hole pipe and a first corrugated fin according to the embodiment. FIG. [Figure 6] 5 is a perspective view of the flat multi-hole pipe and the corrugated fin shown in FIG. 4 with a portion thereof removed. [Figure 7] 7 is a cross-sectional view of the outdoor unit heat exchanger taken along line VII-VII in FIG. 2. FIG. [Figure 8] 3 is a perspective view of the outdoor heat exchanger according to the second embodiment, partially showing an enlarged view of a portion V2 in FIG. 2. FIG. [Figure 9] 10 is a perspective view similar to FIG. 8 of the outdoor heat exchanger according to the third embodiment. FIG. [Figure 10] 10 is a perspective view similar to FIG. 8 of the outdoor heat exchanger according to the fourth embodiment. FIG. [Figure 11] 4 shows experimental results of the outdoor unit heat exchanger according to the present embodiment. [Figure 12] 4 shows experimental results of the outdoor unit heat exchanger according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0010] [First embodiment] The gas heat pump air conditioning system 1 of the present disclosure is an air conditioning system in which a compressor for circulating refrigerant within the system is driven by a gas engine, which is an internal combustion engine. Figure 1 shows a refrigerant circuit diagram of the gas heat pump air conditioning system 1 according to this embodiment.

[0011] The gas heat pump air conditioning system 1 comprises an outdoor unit 2 installed outdoors, an indoor unit 3 installed indoors, and air conditioning refrigerant piping 4 connecting the outdoor unit 2 and the indoor unit 3. The outdoor unit 2 comprises a compressor 5 that compresses the refrigerant to a high-temperature, high-pressure state and circulates the refrigerant within the system, an outdoor unit heat exchanger 6 for exchanging heat between the refrigerant and outside air, an outdoor unit fan 7 that blows outside air to the outdoor unit heat exchanger 6, an expansion valve 8 that decompresses the high-pressure refrigerant, and a four-way valve 9 that switches between cooling and heating by switching the direction of refrigerant flow.

[0012] The outdoor unit 2 further includes a gas engine driving source 12 that drives the compressor 5, a cooling refrigerant pipe 13 for cooling the driving source 12, and a radiator 14 for cooling the heat of the refrigerant in the cooling refrigerant pipe 13. The air conditioning refrigerant pipe 4 and the cooling refrigerant pipe 13 are independent of each other, and the refrigerant in the air conditioning refrigerant pipe 4 and the refrigerant in the cooling refrigerant pipe 13 do not mix.

[0013] The indoor unit 3 includes an indoor unit heat exchanger 10 that exchanges heat with the indoor air, and an indoor unit fan 11 that blows the indoor air to the indoor unit heat exchanger 10 and blows the indoor air that has exchanged heat with the indoor unit heat exchanger 10 back into the room.

[0014] Next, the operation of the gas heat pump air conditioning system 1 during heating operation will be described. When the gas heat pump air conditioning system 1 is operating, the compressor 5 is driven, and the refrigerant in the air conditioning refrigerant pipe 4 is compressed and circulated in direction A1 in Figure 1. The refrigerant, compressed by the compressor 5 to a high-temperature, high-pressure state, transfers heat to the indoor air blown by the indoor unit fan 11 in the indoor unit heat exchanger 10 of the indoor unit 3, thereby warming the indoor air. After passing through the indoor unit 3, the refrigerant passes through the expansion valve 8 of the outdoor unit 2 to a low-temperature, low-pressure state. The low-temperature, low-pressure refrigerant then exchanges heat with outdoor air blown by the outdoor unit fan 7 in the outdoor unit heat exchanger 6, thereby receiving heat from the outdoor air. This cools the outdoor air. The refrigerant is then compressed again by the compressor 5 and circulates toward the indoor unit 3 in a high-temperature, high-pressure state.

[0015] A driving source 12 is connected to the compressor 5. When the compressor 5 is driven, the driving source 12 generates heat. A cooling refrigerant pipe 13 is connected to the driving source 12, and the driving source 12 is cooled by the refrigerant in the cooling refrigerant pipe 13. The refrigerant that has received heat by cooling the heated driving source 12 flows toward a radiator 14 connected to the cooling refrigerant pipe 13 (direction B1 in FIG. 1 ), and transfers heat to the outside air by exchanging heat with the outside air blown by the outdoor unit fan 7 in the radiator 14. The refrigerant that has transferred heat to the outside air circulates toward the driving source 12 and cools the driving source 12 again.

[0016] During cooling operation, the refrigerant circuit is switched by the four-way valve 9, causing the refrigerant to circulate in direction A2 (opposite to A1) in Figure 1. At this time, the opposite phenomenon to that during heating operation occurs in each of the heat exchangers 6 and 10. That is, in the indoor unit heat exchanger 10, the refrigerant receives heat from the indoor air, thereby cooling the indoor air, and in the outdoor unit heat exchanger 6, the refrigerant gives heat to the outdoor air, thereby warming the outdoor air. The operation of the gas heat pump air conditioning system 1 described above is similar to that of a general gas heat pump air conditioning system.

[0017] Next, the arrangement of the outdoor unit heat exchanger 6 and the radiator 14 according to this embodiment will be described with reference to Figures 2 and 3. Figure 2 is a perspective view of the outdoor unit heat exchanger 6 and the radiator 14. In Figure 2, when the gas heat pump air conditioning system 1 is in operation, the outdoor unit fan 7 causes air to flow towards the front of the page. Here, a direction that is perpendicular to the air flow direction (ventilation direction) and vertical is referred to as a first direction (the up-down direction in Figure 1), and a direction perpendicular to the ventilation direction and the first direction is referred to as a second direction (the horizontal direction in Figure 1).

[0018] The outdoor unit heat exchanger 6 has a plurality of flat multi-hole pipes 62 and a plurality of corrugated fins 63 (see FIG. 4 ), and is equipped with a core portion 61 extending in a first direction and a second direction, two flat side plates 65 connected to both ends of the core portion 61 in the second direction and extending in the ventilation direction and the first direction, and two cylindrical headers 64 connected to both ends of the core portion 61 in the first direction and extending in the second direction. The outdoor unit heat exchanger 6 is a so-called microchannel heat exchanger. Refrigerant flowing through the air-conditioning refrigerant piping 4 to the outdoor unit heat exchanger 6 enters one of the headers 64 and flows through the core portion 61 in the first direction. While flowing through the core portion 61 in the first direction, the refrigerant exchanges heat with outside air. After passing through the core portion 61, the refrigerant flows into the other header 64 and exits the outdoor unit heat exchanger 6. 2, pipes extend from both headers 64. The pipe extending from the lower header 64 is bent toward the front of the paper (downstream in the direction of ventilation) and also bent upward. Generally, the bending direction of the pipe in the direction of the paper coincides with the downstream side in the direction of ventilation.

[0019] The radiator 14 is a so-called cross-fin tube heat exchanger made up of multiple copper tubes and multiple fins, and extends in the first and second directions. The radiator is not limited to a cross-fin tube heat exchanger, and may be another type of heat exchanger, such as a microchannel heat exchanger. The radiator 14 is disposed downstream of the outdoor unit heat exchanger 6 in the ventilation direction and below the outdoor unit heat exchanger 6 in the first direction. The radiator 14 is positioned relative to the outdoor unit heat exchanger 6 by fixing both ends of the radiator 14 in the second direction to side plates 65 of the outdoor unit heat exchanger 6 with screws or the like.

[0020] The core portion 61 has a first core portion 61a on the lower side in the first direction and a second core portion 61b on the upper side in the first direction. In the first embodiment, the first core portion 61a faces the radiator 14 in the airflow direction, and the second core portion 61b does not face the radiator 14 in the airflow direction. That is, in FIG. 2, the boundary between the first core portion 61a and the second core portion 61b coincides with the upper edge of the radiator 14.

[0021] FIG. 3 is a side view of the outdoor unit heat exchanger 6 and the radiator 14 viewed from the second direction. Some components, such as the side plate 65, are omitted. The radiator 14 is adjacent to the first core portion 61a of the outdoor unit heat exchanger 6 on the downstream side in the ventilation direction. Here, "adjacent" in this specification means that the distance between them is 5 mm or more and 15 mm or less. That is, the distance L1 in the ventilation direction between the radiator 14 and the first core portion 61a is 5 mm or more and 15 mm or less. More specifically, the distance L1 is the distance in the ventilation direction between the radiator 14 and the first corrugated fins 63a of the first core portion 61a (see FIGS. 4 and 5). That is, the radiator 14 is adjacent to the first corrugated fins 63a on the downstream side in the ventilation direction. It is preferable that the radiator 14 be as close as possible to the first corrugated fins 63a without contacting them.

[0022] 3, the length in the first direction of the radiator 14 is approximately 2 / 3 of the length in the first direction of the core portion 61. In other words, the length in the first direction of the first core portion 61a is approximately 2 / 3 of the length in the first direction of the core portion 61.

[0023] Next, the structure of the outdoor unit heat exchanger 6 according to the first embodiment will be described with reference to FIGS. 4 to 7. FIG. 4 shows a perspective view of two core portions 61a, 61b, partially enlarging and illustrating portion V1 of the outdoor unit heat exchanger of FIG. 2. The core portion 61 of the outdoor unit heat exchanger 6 extends in the ventilation direction and the first direction and includes a plurality of flat multi-hole tubes 62 arranged side by side in the second direction, and a plurality of corrugated fins 63 arranged side by side in the second direction between the plurality of flat multi-hole tubes 62 and extending in a wavy pattern in the first direction. In other words, the plurality of corrugated fins 63 are respectively arranged in a plurality of spaces formed between the plurality of flat multi-hole tubes 62 and wavy in the first direction.

[0024] The corrugated fins 63 are formed in a wave shape by zigzagging a thin metal film having a thickness of, for example, 0.1 mm or less at a predetermined fin pitch P1. The crests and troughs of the corrugated fins 63 are joined to the end faces of the adjacent flat multi-hole tubes 62 in the second direction by a method such as furnace brazing. The refrigerant flowing through the flat multi-hole tubes 62 exchanges heat with the outside air via the corrugated fins 63 joined to the flat multi-hole tubes 62. The corrugated fins 63 are thin and therefore easily deformed when in contact with other components.

[0025] The corrugated fin 63 has a first corrugated fin 63a on the lower side in the first direction and a second corrugated fin 63b on the upper side in the second direction. The first corrugated fin 63a extends in the first direction from the lower end of the corrugated fin 63 to the upper edge of the radiator 14. The second corrugated fin 63b extends from the upper edge of the radiator 14 to the upper end of the corrugated fin 63. The first core portion 61a is composed of a flat multi-hole pipe 62 and the first corrugated fin 63a, and the second core portion 61b is composed of a flat multi-hole pipe 62 identical to the flat multi-hole pipe 62 constituting the first core portion 61a and the second corrugated fin 63b. In this embodiment, the first corrugated fin 63a is formed separately from the second corrugated fin 63b. The first corrugated fin 63a may be formed integrally with the second corrugated fin 63b.

[0026] The corrugated fins 63 are subjected to a hydrophilic coating treatment to improve drainage. Any hydrophilic coating material may be used, but for example, Excel Pure manufactured by Chuo Jidosha Kogyo Co., Ltd. may be used.

[0027] Fig. 5 shows only the flat multi-hole pipe 62 and the first corrugated fin 63a from above. As shown in Figs. 4 and 5, the flat multi-hole pipe 62 has a large number of small holes 621 arranged in the ventilation direction on its end surface in the first direction. The small holes 621 penetrate the flat multi-hole pipe 62 in the first direction and form refrigerant flow paths in the first direction within the flat multi-hole pipe 62. The flat multi-hole pipes 62 are also arranged at equal intervals of approximately 8 mm in the second direction.

[0028] 5, the first corrugated fin 63a includes a central portion 635 joined to the flat multi-hole tube 62, a downstream protruding portion 631 that protrudes downstream in the ventilation direction from the flat multi-hole tube 62 at a downstream end of the central portion 635 in the ventilation direction, and an upstream protruding portion 632 that protrudes upstream in the ventilation direction from the flat multi-hole tube 62 at an upstream end of the central portion 635 in the ventilation direction. The length of the downstream protruding portion 631 in the ventilation direction is equal to the length of the upstream protruding portion 632 in the ventilation direction. The downstream protruding portion 631 and the upstream protruding portion 632 are not in contact with the flat multi-hole tube 62. Therefore, the heat transfer coefficients of the downstream protruding portion 631 and the upstream protruding portion 632 are lower than the heat transfer coefficient of the central portion 635 that is in contact with the flat multi-hole tube 62 through which the refrigerant flows. The first corrugated fin 63a of the first embodiment has a uniform heat transfer coefficient in the airflow direction compared to when the corrugated fin has only a downstream protrusion or an upstream protrusion, which facilitates efficient heat exchange with the outside air. Furthermore, as will be described in detail later, in another aspect, the first corrugated fin 63a may protrude only downstream in the airflow direction, rather than protruding upstream in the airflow direction, in order to minimize deformation of the corrugated fin.

[0029] Although detailed illustration is omitted, the second corrugated fin 63b has a central portion 635 similar to the first corrugated fin 63a, but does not have a downstream protruding portion 631 or an upstream protruding portion 632. In other words, the second corrugated fin 63b does not protrude downstream or upstream in the ventilation direction relative to the flat multi-hole pipe 62. That is, both ends of the second corrugated fin 63b in the ventilation direction coincide with both ends of the flat multi-hole pipe in the ventilation direction.

[0030] The first and second corrugated fins 63a and 63b further include downstream and upstream louver slits 633 and 634, respectively, on the downstream and upstream sides of the central portion 635 in the airflow direction to improve the heat transfer coefficient of the corrugated fin 63. FIG. 6 is a perspective view of a portion of the core portion 61, with portions of the flat multi-hole tube 62 and the corrugated fin 63 removed to expose the respective louver slits 633 and 634. The downstream louver slits 633 are slits that slope upward toward the downstream side in the airflow direction. The upstream louver slits 634 are slits that slope upward toward the upstream side in the airflow direction. Fluid (air or water) around the corrugated fin 63 can move in the first direction through the louver slits 633 and 634. The louver slits 633 and 634 according to this embodiment have a structure similar to that of the louver slits described in, for example, Japanese Patent No. 6400257, and are therefore well-known.

[0031] 4, the outdoor unit heat exchanger 6 is provided with a plurality of water flow paths 66 in the second direction, each of which is configured on the downstream side in the ventilation direction by two downstream protrusions 631 and the ventilation direction end faces of the flat multi-hole pipes 62 and extends in the first direction. The water flow paths 66 are paths for discharging water defrosted by the corrugated fins 63. The water flow paths 66 are also configured on the upstream side in the ventilation direction by two upstream protrusions 632 and the ventilation direction end faces of the flat multi-hole pipes 62 and extend in the first direction.

[0032] FIG. 7 is a partial cross-sectional view of the outdoor heat exchanger 6 taken along line VII-VII in FIG. 2, showing the vicinity of the lower end of the outdoor heat exchanger 6 in the first direction. The flat multi-hole pipe 62 is inserted into the header 64 and joined by a method such as furnace brazing. In FIG. 7, the center of the header 64, the center of the width of the flat multi-hole pipe 62 in the ventilation direction, and the center of the width of the corrugated fin 63 in the ventilation direction are aligned in the ventilation direction. The width w1 of the first corrugated fin 63a in the ventilation direction is equal to or less than the width of the header 64 in the ventilation direction, i.e., the outer diameter d1, and is greater than the width w2 of the flat multi-hole pipe 62 in the ventilation direction. That is, the lengths of the downstream protrusion 631 and the upstream protrusion 632 of the first corrugated fin 63a in the ventilation direction are determined so that the width w1 is equal to or less than the outer diameter d1 and greater than the width w2. By making the width w1 equal to or smaller than the outer diameter d1, it is possible to reduce the possibility of the first corrugated fins 63a coming into contact with the floor surface and being deformed when the outdoor heat exchanger 6 is stored with the surface formed by the first and second directions facing downward. Furthermore, by making the width w1 larger than the width w2, the space in the ventilation direction of the first corrugated fins 63a can be effectively used.

[0033] Next, we will explain the frosting phenomenon that occurs in the outdoor unit heat exchanger 6 during heating operation and the defrosting method in this embodiment. Because the refrigerant in the outdoor unit heat exchanger 6 receives heat from the outside air, the temperature of the refrigerant is about 5°C lower than the outside air temperature. That is, for example, when the outside air temperature is 0°C, the temperature of the refrigerant is about -5°C. The temperature of the corrugated fins 63 depends on the temperature of the refrigerant flowing through the flat multi-hole pipes 62, and is similarly about -5°C. When air passing through the corrugated fins 63 in the ventilation direction is cooled to 0°C or below by the corrugated fins 63, the moisture in the air turns into frost or ice and adheres to the corrugated fins 63. This phenomenon is called frosting.

[0034] If frost continues to accumulate on the corrugated fins 63, the frost may clog the ventilation passages of the corrugated fins 63, deteriorating the heat transfer performance of the outdoor unit heat exchanger 6 and ultimately leading to a deterioration in the performance of the air conditioning system. To melt the frost, i.e., to defrost, a defrosting operation is typically performed by temporarily switching the four-way valve to circulate high-temperature, high-pressure refrigerant from the indoor unit to the outdoor unit, thereby defrosting the outdoor unit heat exchanger. In the gas heat pump air conditioning system 1 of this embodiment, the radiator 14 is adjacent to the outdoor unit heat exchanger 6 downstream in the ventilation direction, and the first corrugated fin 63a has a downstream protrusion 631 on the downstream side in the ventilation direction, i.e., on the radiator 14 side. The temperature of the radiator 14 is a high temperature of approximately 85°C. As a result, heat from the radiator 14 is transferred to the downstream protrusions 631 of the first corrugated fins 63a via the air between the radiator 14 and the outdoor unit heat exchanger 6, heating the first corrugated fins 63a and defrosting the frost that has accumulated on the first corrugated fins 63a. In other words, the gas heat pump air conditioning system 1 of this embodiment does not require switching of the four-way valve, and efficient defrosting can be achieved even in an air conditioning system that does not have a four-way valve. At this time, it is preferable that the outdoor unit fan 7 is not operating.

[0035] Furthermore, liquid water generated during the frosting process flows downward in the first direction due to gravity through the louver slits 633, 634, so frost is likely to form on the lower corrugated fins. In this embodiment, the radiator 14 is disposed below the outdoor unit heat exchanger 6, and the first corrugated fins 63a facing the radiator 14 protrude downstream in the ventilation direction, allowing for efficient defrosting.

[0036] On the other hand, because these protrusions 631, 632 are exposed from the outdoor unit heat exchanger 6, they may be deformed by coming into contact with other components when assembling the outdoor unit heat exchanger 6 or the gas heat pump air conditioning system 1. When the gas heat pump air conditioning system 1 is installed, the corrugated fins 63 are exposed, and deformation of the corrugated fins 63 is undesirable from the viewpoint of appearance.

[0037] In this embodiment, the upper second corrugated fins 63b do not protrude upstream or downstream in the airflow direction, reducing the possibility of contact with other components. This minimizes deformation of the corrugated fins 63. As a result, the aesthetic appearance of the outdoor unit heat exchanger 6 is less likely to be impaired. Furthermore, as described above, frost is relatively unlikely to form on the upper corrugated fins, so even if the upper second corrugated fins 63b do not protrude in the airflow direction, there is little impact on the deterioration of the heat transfer performance of the outdoor unit heat exchanger 6.

[0038] When the first corrugated fins 63a do not protrude upstream in the ventilation direction, deformation of the upstream side of the first corrugated fins 63a can be suppressed, and the aesthetic appearance of the outdoor unit heat exchanger 6 is less likely to be impaired.

[0039] Meanwhile, the melted frost turns to water, which flows downward in the first direction according to gravity through the louver slits 633, 634 of the corrugated fins 63, collects in a drain pan (not shown) separately provided in the outdoor unit 2, and is then discharged to the outside. If the amount of defrosting is large and water overflows from the louver slits 633, 634, the water flows in the second direction according to the slope formed by the corrugated shape of the corrugated fins 63, passes through a water flow path 66 formed by the two downstream protrusions 631 and the flat multi-hole pipes 62, and collects in the drain pan (see water flow direction f1 in FIG. 4). When a water flow is formed in the water flow path 66, the water on the corrugated fins 63 around the water flow path 66 is drawn into the flow of the water flow path 66, further improving drainage efficiency.

[0040] Furthermore, the corrugated fins 63 of this embodiment are subjected to a hydrophilic coating treatment, so that water flowing over the corrugated fins 63 can be discharged more efficiently.

[0041] The gas heat pump air conditioning system 1 according to the first embodiment has the following advantages.

[0042] (1) The gas heat pump air conditioning system 1 is a plurality of flat multi-hole pipes 62 extending in a ventilation direction and a first direction perpendicular to the ventilation direction and arranged side by side in a second direction perpendicular to the ventilation direction and the first direction; a plurality of corrugated fins 63 arranged in parallel in the second direction between the plurality of flat multi-hole pipes 62 and extending in a wavy manner in the first direction; The heat exchanger 6 for an outdoor unit is provided with the corrugated fins 63. a plurality of first corrugated fins (63a) provided on one side in the first direction and protruding downstream in the ventilation direction relative to the plurality of flat multi-hole pipes (62); a plurality of second corrugated fins 63b provided on the other side of the first direction and not projecting toward the upstream side or downstream side of the ventilation direction relative to the plurality of flat multi-hole pipes 62; It has a compressor 5; a drive source 12 that drives the compressor 5; a radiator 14 adjacent to the plurality of first corrugated fins 63a on the downstream side in the ventilation direction and for cooling the driving source 12; Equipped with.

[0043] As a result, frost that accumulates on the first corrugated fins 63a during heating operation is efficiently defrosted by the heat of the radiator 14, thereby preventing deterioration of the heat transfer performance of the outdoor unit heat exchanger 6. Moreover, because the first corrugated fins 63a protrude downstream in the airflow direction, water generated by defrosting can be efficiently discharged. Furthermore, because the second corrugated fins 63b do not protrude upstream or downstream in the airflow direction, deformation of the second corrugated fins 63b due to contact with other components can be prevented, and the aesthetic appearance of the outdoor unit heat exchanger 6 can be maintained.

[0044] (2) The first corrugated fins 63a do not protrude upstream in the airflow direction relative to the flat multi-hole pipes 62.

[0045] As a result, deformation of the first corrugated fin 63a due to contact with other parts can be suppressed compared to when the first corrugated fin 63a protrudes upstream in the ventilation direction, and the aesthetic appearance of the outdoor unit heat exchanger 6 can be further maintained.

[0046] (3) In a position where the first direction of the outdoor unit heat exchanger 6 is the vertical direction, The plurality of first corrugated fins 63a are provided at the lower end of the corrugated fin 63.

[0047] As a result, since the first corrugated fins 63a are provided below the corrugated fins 63 where frost is likely to form, defrosting can be performed efficiently.

[0048] (4) The corrugated fins 63 are subjected to a hydrophilic coating treatment.

[0049] As a result, the drainage of water flowing on the corrugated fins 63 is improved, and frost formation can be further suppressed.

[0050] (5) A plurality of flat multi-hole pipes 62 extending in a ventilation direction and a first direction perpendicular to the ventilation direction and arranged side by side in a second direction perpendicular to the ventilation direction and the first direction; a plurality of corrugated fins 63 arranged in parallel in the second direction between the plurality of flat multi-hole pipes 62 and extending in a wavy manner in the first direction; The heat exchanger 6 for an outdoor unit is provided with a plurality of corrugated fins 63, a plurality of first corrugated fins (63a) provided on one side in the first direction and protruding downstream in the ventilation direction relative to the plurality of flat multi-hole pipes (62); a plurality of second corrugated fins 63b provided on the other side of the first direction and not projecting toward the upstream side or downstream side of the ventilation direction relative to the plurality of flat multi-hole pipes 62; It has.

[0051] As a result, the first corrugated fins 63a protrude downstream in the ventilation direction, allowing water generated by defrosting to be efficiently discharged. Furthermore, the second corrugated fins 63b do not protrude upstream or downstream in the ventilation direction, preventing deformation of the second corrugated fins 63b due to contact with other components, thereby maintaining the aesthetic appearance of the outdoor unit heat exchanger 6.

[0052] [Second embodiment] Fig. 8 is a perspective view of the outdoor heat exchanger 6a according to the second embodiment, partially enlarging the V2 portion of Fig. 2. The side plate 65 is omitted. Only the configuration different from the first embodiment will be described below.

[0053] In FIG. 8, the first corrugated fin 63a extends upward in the first direction from the lower end of the corrugated fin 63 (i.e., the lower end of the first corrugated fin 63a) to a height H. In the second embodiment, the height H is 30 mm. In other words, the first corrugated fin 63a in the second embodiment extends in a zigzag pattern with approximately 10 ridges. Therefore, in the second embodiment, the radiator 14 is disposed adjacent to the first corrugated fin 63a and the second corrugated fin 63b on the downstream side in the ventilation direction.

[0054] Therefore, the dimension in the first direction of the first corrugated fins 63a in the second embodiment is shorter than the dimension in the first direction of the first corrugated fins 63a in the first embodiment, which reduces the proportion of the corrugated fins 63a in the corrugated fin 63, thereby further suppressing deformation of the corrugated fins 63 due to contact with other components.

[0055] [Third embodiment] Fig. 9 is a perspective view similar to Fig. 8 of an outdoor heat exchanger 6b according to a third embodiment. For convenience of explanation, the second corrugated fins 63b at the front end of the paper in the second direction are omitted. Only the configurations different from the first and second embodiments will be described below.

[0056] In the first and second embodiments, the main surface (i.e., the protruding portions 631, 632 and the central portion 635) of the first corrugated fin 63a that faces the first direction has louver slits 633, 634. However, as shown in Fig. 9, the main surface 637 of the first corrugated fin 63a in the third embodiment is flat and does not have any holes. That is, the main surface 637 does not have the louver slits 633, 634.

[0057] 6, the louver slits 633, 634 are inclined upward in the first direction, and therefore the flow of fluid in the ventilation direction of the first corrugated fin 63a may be obstructed by the louver slits 633, 634. As a result, moisture generated by defrosting may accumulate near the louver slits 633, 634 and may not be efficiently discharged.

[0058] The main surface 637 of the first corrugated fin 63a of the third embodiment does not have the louver slits 633, 634 and is flat, eliminating factors that hinder the flow of water on the main surface 637. As a result, water generated by defrosting can be discharged more efficiently.

[0059] According to the gas heat pump air conditioning system of the third embodiment, The first corrugated fins 63a each have a flat main surface 637 that faces the first direction, The main surface 637 does not have any holes.

[0060] As a result, the water produced by defrosting can be discharged more efficiently.

[0061] [Fourth embodiment] Fig. 10 is a perspective view similar to Fig. 8 of an outdoor unit heat exchanger 6c according to a fourth embodiment. For convenience of explanation, the second corrugated fin 63b at the front end of the paper in the second direction and the downstream louver slit portion 633 of the first corrugated fin 63a at the upper end of the front end of the paper in the second direction are omitted. Only the configuration different from the first, second, and third embodiments will be described below.

[0062] As shown in FIG. 10 , drainage holes 636 are provided in the main surface 637 of the first corrugated fin 63a. Specifically, the drainage holes 636 are provided in the downstream protrusion 631. The drainage holes 636 have a substantially rectangular shape when viewed from the first direction. The dimensions of each side of the drainage holes 636 can be set to a range of 2 mm or more so that water generated by defrosting can be effectively discharged. In the fourth embodiment, the dimensions of each side of the drainage hole 636 are approximately 7 mm on one side and approximately 7 mm on the other side. This configuration allows water generated by defrosting to be discharged even more efficiently.

[0063] According to the gas heat pump air conditioning system of the fourth embodiment, The first corrugated fins 63a each have a flat main surface 637 that faces the first direction, The main surface 637 is provided with drainage holes 636 .

[0064] As a result, the water produced by defrosting can be drained even more efficiently.

[0065] [Example] Next, specific examples of the heat exchanger for an outdoor unit according to the present disclosure will be described along with comparative examples. As shown in Table 1, examples 1-7 and comparative examples 1-4 were prepared, and experiments were conducted to evaluate the drainage performance of the corrugated fins. Specifically, the experiment involved spraying water toward the entire core of the heat exchanger for an outdoor unit, with the first direction of the heat exchanger oriented vertically. As water continued to be sprayed, the water accumulated up to a predetermined height from the bottom of the corrugated fins. Further spraying of water prevented the water from accumulating above the predetermined height and began to overflow from the corrugated fins. This predetermined height is referred to as the water retention height. In other words, a high water retention height indicates poor drainage performance of the corrugated fins, while a low water retention height indicates excellent drainage performance of the corrugated fins. In this experiment, the water retention heights of each example and comparative example were measured and compared.

[0066] [Table 1]

[0067] Next, the configurations of the examples and comparative examples will be described.

[0068] [Examples 1-4] The outdoor unit heat exchanger of Example 1-4 is formed by fixing corrugated fins each having a thickness of approximately 0.1 mm between a plurality of flat multi-hole tubes arranged in a row at intervals of approximately 8 mm. The corrugated fins of Example 1-4 are 38 mm long in the airflow direction and protrude 3 mm upstream and downstream from the flat multi-hole tubes in the airflow direction. In Example 1-4, the fin pitch (see Figure 4) of the corrugated fins was varied from 1.2 mm to 1.6 mm. The corrugated fins of Example 1-4 were not subjected to a hydrophilic coating treatment and had no drainage holes. The corrugated fins of Example 1-4 had upstream and downstream louver slits.

[0069] [Example 5] The corrugated fin of Example 5 was obtained by applying a hydrophilic coating to the corrugated fin of Example 2.

[0070] [Example 6] The corrugated fin of Example 6 has the same configuration as the corrugated fin of Example 2, except that it does not have louver slits. That is, the corrugated fin of Example 6 corresponds to the first corrugated fin 63a of the third embodiment.

[0071] [Example 7] The corrugated fins of Example 7 are the same as those of Example 2 except that they are provided with drainage holes. That is, the corrugated fins of Example 7 correspond to the first corrugated fins 63a of the fourth embodiment.

[0072] [Comparative Example 1-4] The corrugated fin of Comparative Example 1-4 has the same configuration as Example 1-4, except that it does not protrude upstream or downstream in the ventilation direction relative to the flat multi-hole pipe. Specifically, both ends of the corrugated fin of Comparative Example 1-4 in the ventilation direction coincide with both ends of the flat multi-hole pipe in the ventilation direction. Therefore, the length of the corrugated fin of Comparative Example 1-4 in the ventilation direction is 32 mm.

[0073] [Experimental result 1] Figure 11 shows the experimental results for Comparative Example 1-4 and Example 1-4. The horizontal axis represents the fin pitch, and the vertical axis represents the water retention height. In Figure 11, the black circles represent the experimental results for Comparative Example 1-4, and the black squares represent the experimental results for Example 1-4.

[0074] At any fin pitch, the water retention height of Example 1-4, which has protrusions, is lower than that of Comparative Example 1-4, which does not have protrusions. Furthermore, the maximum water retention height in the range confirmed in this experiment was approximately 30 mm. In other words, the range of the corrugated fin where drainage performance needs to be particularly improved is the range from the bottom end of the corrugated fin to a height of at least 30 mm.

[0075] [Experimental result 2] The experimental results for Examples 2 and 5-7 are shown in Figure 12. The vertical axis represents the water retention height.

[0076] The water retention heights of Examples 5-7 are lower than that of Example 2. In particular, by applying a hydrophilic coating to the corrugated fins, the water retention height is significantly reduced.

[0077] From the above experimental results, the inventors have made the following findings. a. By projecting the corrugated fins in the direction of ventilation from the flat multi-hole pipe, water can be efficiently discharged. b. By applying a hydrophilic coating to the corrugated fins, water can be drained more efficiently. c. The flat and non-perforated main surfaces of the corrugated fins allow water to drain more efficiently. d. By providing drainage holes in the corrugated fins, water can be drained more efficiently. e. Water flowing through the corrugated fins accumulates up to a height of 30 mm from the bottom of the fins. Therefore, by applying the technology of the present disclosure to corrugated fins with a height range of at least 30 mm from the bottom of the fins, water can be efficiently drained.

[0078] The gas heat pump air conditioning system and the heat exchanger for the outdoor unit according to the present disclosure are not limited to the configurations of the above-described embodiments, and various modifications are possible.

[0079] In this embodiment, the radiator 14 is disposed below the outdoor unit heat exchanger 6 in the first direction, but the location is not limited to this. Note that water that is not completely drained during defrosting accumulates below the outdoor unit heat exchanger 6 due to gravity and may freeze again, so the lower side in the first direction is more likely to require defrosting. For this reason, it is preferable that the radiator 14 be disposed below the outdoor unit heat exchanger 6 in the first direction.

[0080] The header 64 in this embodiment has a cylindrical shape, but is not limited to this and may have, for example, a rectangular prism shape.

[0081] The hydrophilic coating may be applied only to the first corrugated fins 63a, or may be applied to the entire core portion 61.

[0082] The drainage holes 636 may be provided in the central portion 635 of the first corrugated fin 63a and / or the upstream protruding portion 632. A plurality of drainage holes 636 may be provided on one main surface 637.

[0083] The upstream and downstream louver slits 633, 634 do not necessarily have to be provided on the first corrugated fin 63a and the second corrugated fin 63b.

[0084] The heat exchanger for an outdoor unit of the present disclosure can also be applied to a heat pump type air conditioning system that does not have a radiator, and can advantageously improve drainage performance while maintaining aesthetic appearance.

[0085] The second corrugated fins 63b may be recessed inward in the airflow direction relative to the flat multi-hole pipe. In other words, both ends of the second corrugated fins 63b in the airflow direction may be located more inward than both ends of the flat multi-hole pipe in the airflow direction.

[0086] [Note] The gas heat pump air conditioning system and the heat exchanger for an outdoor unit according to the present disclosure provide the following aspects.

[0087] [Aspect 1] A plurality of flat multi-hole pipes extending in a first direction perpendicular to the ventilation direction and the ventilation direction and arranged side by side in a second direction perpendicular to the ventilation direction and the first direction; a plurality of corrugated fins arranged side by side in the second direction between the plurality of flat multi-hole pipes and extending in a wavy manner in the first direction; and a heat exchanger for an outdoor unit, wherein the corrugated fins are a plurality of first corrugated fins provided on one side of the first direction and protruding downstream in the ventilation direction relative to the plurality of flat multi-hole pipes; a plurality of second corrugated fins provided on the other side of the first direction and not protruding toward the upstream side or downstream side in the ventilation direction relative to the plurality of flat multi-hole pipes; It has A compressor; a drive source that drives the compressor; a radiator adjacent to the plurality of first corrugated fins on the downstream side in the ventilation direction and configured to cool the driving source; A gas heat pump air conditioning system equipped with:

[0088] [Aspect 2] The first corrugated fins do not protrude upstream in the ventilation direction relative to the flat multi-hole pipes. 2. The gas heat pump air conditioning system according to claim 1.

[0089] [Aspect 3] In a position where the first direction of the outdoor unit heat exchanger is a vertical direction, The first corrugated fins are provided at the lower ends of the corrugated fins. 3. The gas heat pump air conditioning system according to claim 1 or 2.

[0090] [Aspect 4] The corrugated fins are subjected to a hydrophilic coating treatment. A gas heat pump air conditioning system according to any one of aspects 1 to 3.

[0091] [Aspect 5] The first corrugated fins each have a flat main surface that faces the first direction, The main surface is free of any holes. A gas heat pump air conditioning system according to any one of aspects 1 to 4.

[0092] [Aspect 6] The first corrugated fins each have a flat main surface that faces the first direction, The main surface is provided with drainage holes. A gas heat pump air conditioning system according to any one of aspects 1 to 4.

[0093] [Aspect 7] A plurality of flat multi-hole pipes extending in a first direction perpendicular to the ventilation direction and the ventilation direction and arranged side by side in a second direction perpendicular to the ventilation direction and the first direction; a plurality of corrugated fins arranged side by side in the second direction between the plurality of flat multi-hole pipes and extending in a wavy manner in the first direction; A heat exchanger for an outdoor unit, comprising: a plurality of first corrugated fins provided on one side of the first direction and protruding downstream in the ventilation direction relative to the plurality of flat multi-hole pipes; a plurality of second corrugated fins provided on the other side of the first direction and not protruding toward the upstream side or downstream side in the ventilation direction relative to the plurality of flat multi-hole pipes; A heat exchanger for an outdoor unit, comprising:

[0094] [Aspect 8] The first corrugated fins do not protrude upstream in the ventilation direction relative to the flat multi-hole pipes. A heat exchanger for an outdoor unit according to aspect 7.

[0095] [Aspect 9] In a position where the first direction of the outdoor unit heat exchanger is a vertical direction, The first corrugated fins are provided at the lower ends of the corrugated fins. A heat exchanger for an outdoor unit according to aspect 7 or 8.

[0096] [Aspect 10] The corrugated fins are subjected to a hydrophilic coating treatment. 10. The heat exchanger for an outdoor unit according to any one of aspects 7 to 9.

[0097] [Aspect 11] The first corrugated fins each have a flat main surface that faces the first direction, The main surface is free of any holes. The heat exchanger for an outdoor unit according to any one of aspects 7 to 10.

[0098] [Aspect 12] The first corrugated fins each have a flat main surface that faces the first direction, The main surface is provided with drainage holes. The heat exchanger for an outdoor unit according to any one of aspects 7 to 10. [Explanation of symbols]

[0099] 1: Gas heat pump air conditioning system 2:Outdoor unit 5: Compressor 6: Heat exchanger for outdoor unit 61: Core section 61a: First core section 61b: Second core section 62: Flat multi-hole pipe 63: Corrugated fin 63a: First corrugated fin 63b: Second corrugated fin 631: Downstream protrusion 632: Upstream protrusion 633: Downstream louver slit 634: Upstream louver slit 635: Central part 636: Drainage hole 637: Main surface 64: Header 14: Radiator d1: Header outer diameter w1: Width of corrugated fin in ventilation direction w2: Width of flat multi-hole pipe in the ventilation direction H1: First corrugated fin height

Claims

1. a plurality of flat multi-hole pipes extending in a first direction perpendicular to the ventilation direction and the ventilation direction, and arranged side by side in a second direction perpendicular to the ventilation direction and the first direction; a plurality of corrugated fins arranged in parallel in the second direction between the plurality of flat multi-hole pipes and extending in a wavy manner in the first direction; and a heat exchanger for an outdoor unit, wherein the corrugated fins are a plurality of first corrugated fins provided on one side of the first direction and protruding downstream in the ventilation direction relative to the plurality of flat multi-hole pipes; a plurality of second corrugated fins provided on the other side of the first direction and not projecting toward the upstream side or downstream side in the ventilation direction relative to the plurality of flat multi-hole pipes; It has A compressor; a drive source that drives the compressor; a radiator adjacent to the plurality of first corrugated fins on the downstream side in the ventilation direction, for cooling the driving source; A gas heat pump air conditioning system equipped with:

2. The first corrugated fins do not protrude upstream in the ventilation direction relative to the flat multi-hole pipes.

2. The gas heat pump air conditioning system according to claim 1.

3. In a position where the first direction of the outdoor unit heat exchanger is a vertical direction, The plurality of first corrugated fins are provided at the lower ends of the corrugated fins.

3. The gas heat pump air conditioning system according to claim 2.

4. The corrugated fins are subjected to a hydrophilic coating treatment.

4. A gas heat pump air conditioning system according to claim 1.

5. The first corrugated fins each have a flat main surface that faces the first direction, The main surface is free of any holes.

4. A gas heat pump air conditioning system according to claim 1.

6. The first corrugated fins each have a flat main surface that faces the first direction, The main surface is provided with drainage holes.

4. A gas heat pump air conditioning system according to claim 1.

7. a plurality of flat multi-hole pipes extending in a first direction perpendicular to the ventilation direction and the ventilation direction, and arranged side by side in a second direction perpendicular to the ventilation direction and the first direction; a plurality of corrugated fins arranged in parallel in the second direction between the plurality of flat multi-hole pipes and extending in a wavy manner in the first direction; A heat exchanger for an outdoor unit, comprising: a plurality of first corrugated fins provided on one side of the first direction and protruding downstream in the ventilation direction relative to the plurality of flat multi-hole pipes; a plurality of second corrugated fins provided on the other side of the first direction and not projecting toward the upstream side or downstream side in the ventilation direction relative to the plurality of flat multi-hole pipes; A heat exchanger for an outdoor unit, comprising:

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