Gas heat pump type air conditioning system

Abstract

To provide a gas heat pump type air conditioning system capable of defrosting frost generated in corrugated fins at the time of heating operation.SOLUTION: A gas heat pump type air conditioning system includes: an exchanger 6 for an outdoor unit including a plurality of flat multihole pipes extending in a ventilation direction and a first direction orthogonal to the ventilation direction, and arranged parallel with each other in the ventilation direction and a second direction orthogonal to the first direction, and a plurality of corrugated fins arranged parallel with each other in the second direction between the plurality of flat multihole pipes, projecting to a downstream side in the ventilation direction relative to the plurality of flat multihole pipes, and extending in corrugated shapes in the first direction; a compressor; a driving source for driving the compressor; and a radiator 14 adjacent to the exchanger for the outdoor unit at a downstream side in the ventilation direction, and cooling the driving source.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a gas heat pump type air conditioning system.

Background Art

[0002] Patent Document 1 discloses an outdoor heat exchanger for a parallel flow type heat pump in which a plurality of flat tubes arranged in parallel and corrugated fins are alternately laminated in a direction perpendicular to the ventilation. According to Patent Document 1, louvers divided into a plurality of groups are provided only on the downstream side from a certain length along the ventilation direction from the ventilation upstream end of the corrugated fin. Thereby, a strong parallel flow type outdoor heat exchanger for a heat pump is provided against clogging due to frost formation on the corrugated fins in the ventilation upstream part that occurs during the heating operation of the air conditioner.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the parallel flow type outdoor heat exchanger for a heat pump described in Cited Document 1, although consideration is given to suppressing the blockage of the ventilation path due to frost formation, it does not have a structure considered for defrosting.

[0005] An object of the present disclosure is to provide a gas heat pump type air conditioning system capable of defrosting frost generated on corrugated fins during the heating operation.

Means for Solving the Problems

[0006] The present disclosure is A plurality of flat multi-hole tubes extending in the ventilation direction and in a first direction orthogonal to the ventilation direction, and arranged side by side in a second direction orthogonal 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 tubes, protruding to the downstream side in the ventilation direction with respect to the plurality of flat multi-hole tubes, and further extending in a wavy manner in the first direction. An outdoor unit heat exchanger provided with the above. A compressor. A drive source for driving the compressor. A radiator adjacent to the outdoor unit heat exchanger on the downstream side in the ventilation direction for cooling the drive source. Provided is a gas heat pump type air conditioning system including the above.

[0007] According to the gas heat pump type air conditioning system according to the present disclosure, since the corrugated fins protrude to the downstream side in the ventilation direction from the flat multi-hole tubes, and the radiator is adjacent to the outdoor unit exchanger on the downstream side, the frost generated on the corrugated fins can be efficiently defrosted by the heat of the radiator.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Mode for Carrying Out 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 type air conditioning system 1 of the present disclosure is a system in an air conditioning system that drives a compressor for circulating a refrigerant in the system by a gas engine that is an internal combustion engine. FIG. 1 shows a refrigerant circuit diagram of the gas heat pump type air conditioning system 1 according to the present embodiment.

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

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

[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 again.

[0014] Next, the operation of the gas heat pump type air conditioning system 1 during the heating operation will be described. When the gas heat pump type air conditioning system 1 operates, the compressor 5 is driven, and the refrigerant in the refrigerant pipe for air conditioning 4 is compressed and circulates in the direction A1 in FIG. 1. The refrigerant compressed by the compressor 5 to a high temperature and high pressure state exchanges heat with the indoor air blown from the indoor unit fan 11 in the indoor unit heat exchanger 10 of the indoor unit 3, thereby giving heat to the indoor air. As a result, the indoor air is warmed. The refrigerant after passing through the indoor unit 3 becomes a low temperature and low pressure state by passing through the expansion valve 8 of the outdoor unit 2. The refrigerant in the low temperature and low pressure state exchanges heat with the outdoor air blown from the outdoor unit fan 7 in the outdoor unit heat exchanger 6, thereby receiving heat from the outdoor air. As a result, the outdoor air is cooled. The subsequent refrigerant is compressed again by the compressor 5 and circulates toward the indoor unit 3 in a high temperature and high pressure state.

[0015] A drive source 12 is connected to the compressor 5. By driving the compressor 5, the drive source 12 generates heat. A refrigerant pipe 13 for cooling is connected to the drive source 12, and the drive source 12 is cooled by the refrigerant in the refrigerant pipe 13 for cooling. The refrigerant that has received heat by cooling the heat-generating drive source 12 flows toward a radiator 14 connected to the refrigerant pipe 13 for cooling (in the direction B1 in FIG. 1), and exchanges heat with the outside air blown from the outdoor unit fan 7 in the radiator 14, thereby giving the heat to the outside air. The refrigerant that has given the heat to the outside air circulates toward the drive source 12 and cools the drive source 12 again.

[0016] During the cooling operation, the refrigerant circuit is switched by the four-way valve 9, so that the refrigerant circulates in the direction A2 (opposite to A1 in FIG. 1) in FIG. 1. At this time, opposite phenomena occur in the respective heat exchangers 6 and 10 during the heating operation. 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 outside air, thereby warming the outside air. The operation of the gas heat pump type air conditioning system 1 described above is the same as the operation of a general gas heat pump type air conditioning system.

[0017] Next, the arrangement of the outdoor unit heat exchanger 6 and the radiator 14 according to the present embodiment will be described with reference to FIGS. 2 and 3. FIG. 2 is a perspective view of the outdoor unit heat exchanger 6 and the radiator 14. In FIG. 2, during the operation of the gas heat pump type air conditioning system 1, air is flowing toward the front side of the paper by the outdoor unit fan 7. Here, a direction that is orthogonal to the direction in which the air flows (ventilation direction) and is vertical is referred to as the first direction (the vertical direction in FIG. 1), and a direction that is orthogonal to the ventilation direction and the first direction is referred to as the second direction (the horizontal direction in FIG. 1). In FIG. 2, pipes extend from both headers 64, respectively. The pipe extending from the lower header 64 is bent toward the front side of the paper (downstream side in the ventilation direction) and bent upward. Generally, the bending direction of the pipe in the paper surface direction coincides with the downstream side in the ventilation direction.

[0018] The outdoor unit heat exchanger 6 has a plurality of flat multi-hole tubes 62 and a plurality of corrugated fins 63 (see FIG. 4), and includes a core portion 61 extending in a first direction and a second direction, and 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 type heat exchanger. The refrigerant flowing through the air-conditioning refrigerant pipe 4 into the outdoor unit heat exchanger 6 enters one header 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 the outside air. The refrigerant that has passed through the core portion 61 flows into the other header 64 and exits the outdoor unit heat exchanger 6.

[0019] The radiator 14 is a so-called cross fin tube type heat exchanger composed of a plurality of copper tubes and a plurality of fins, and extends in a first direction and a second direction. The radiator is not limited to a cross fin tube type heat exchanger, and may be other types of heat exchangers such as a microchannel type heat exchanger. The radiator 14 is disposed on the downstream side in the ventilation direction and the lower side in the first direction with respect to the outdoor unit heat exchanger 6. The radiator 14 is positioned with respect to the outdoor unit heat exchanger 6 by fixing both end portions of the radiator 14 in the second direction to the side plates 65 of the outdoor unit heat exchanger 6 with screws or the like.

[0020] FIG. 3 is a side view of the outdoor heat exchanger 6 and the radiator 14 as viewed from the second direction. Some components such as the side plate 65 are omitted. The radiator 14 is adjacent to the outdoor heat exchanger 6 on the downstream side in the ventilation direction. Here, "adjacent" in this specification means that the distance between the two is 5 mm or more and 15 mm or less. That is, the ventilation direction distance L1 between the radiator 14 and the outdoor heat exchanger 6 is 5 mm or more and 15 mm or less. Specifically, the distance L1 is the ventilation direction distance between the radiator 14 and the corrugated fin 63 (see FIGS. 4 and 5) of the outdoor heat exchanger 6. The radiator 14 is preferably as close as possible without contacting the corrugated fin 63.

[0021] Subsequently, the structure of the outdoor heat exchanger 6 according to this embodiment will be described with reference to FIGS. 4 to 7. FIG. 4 shows a perspective view of a part of the core part 61 of the outdoor heat exchanger 6. The outdoor heat exchanger 6 extends in the ventilation direction and the first direction and is arranged in parallel in the second direction, and a plurality of flat multi-hole tubes 62, and are arranged in parallel in the second direction between the plurality of flat multi-hole tubes 62, and project to the downstream side and the upstream side in the ventilation direction with respect to the plurality of flat multi-hole tubes 62, and further extend in a wavy manner in the first direction, and a plurality of corrugated fins 63. 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 are wavy in the first direction.

[0022] FIG. 5 is a top view of FIG. 4. As shown in FIGS. 4 and 5, a large number of small holes 621 are provided side by side in the ventilation direction on the end face in the first direction of the flat multi-hole tube 62. The small holes 621 penetrate the flat multi-hole tube 62 in the first direction and form a refrigerant flow path in the first direction in the flat multi-hole tube 62. In addition, the respective flat multi-hole tubes 62 are arranged at equal intervals of about 8 mm in the second direction.

[0023] The corrugated fin 63 is formed in a wave shape, for example, by folding a thin-film metal with a thickness of 0.1 mm or less in a zigzag pattern at a predetermined fin pitch P1. The corrugated fin 63 is joined to the end faces in the second direction of a plurality of adjacent flat multi-hole tubes 62 by a method such as in-furnace brazing at the peak and valley portions of the waves. The refrigerant flowing through the flat multi-hole tube 62 exchanges heat with the outside air through the corrugated fin 63 joined to the flat multi-hole tube 62. Since the corrugated fin 63 has a small thickness, it is a component that is easily deformed by contact with other components. As shown in FIG. 5, the corrugated fin 63 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 with respect to the flat multi-hole tube 62 at the downstream end of the central portion 635 in the ventilation direction, and an upstream protruding portion 632 that protrudes upstream in the ventilation direction with respect to the flat multi-hole tube 62 at the 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. Further, the downstream protruding portion 631 and the upstream protruding portion 632 do not contact the flat multi-hole tube 62. Therefore, the heat transfer coefficient of the downstream protruding portion 631 and the upstream protruding portion 632 is smaller than the heat transfer coefficient of the central portion 635 that contacts the flat multi-hole tube 62 through which the refrigerant flows. The corrugated fin 63 of the present embodiment has a uniform heat transfer coefficient of the corrugated fin in the ventilation direction compared to the case where the corrugated fin has only one of the downstream protruding portion or the upstream protruding portion, and thus is easily heat-exchanged with the outside air efficiently.

[0024] The corrugated fin 63 further has a downstream louver slit portion 633 and an upstream louver slit portion 634 for improving the heat transfer rate of the corrugated fin 63 on the downstream side and the upstream side in the ventilation direction of the central portion 635, respectively. FIG. 6 is a perspective view of a part of the core portion 61 with a part of the flat multi-hole tube 62 and the corrugated fin 63 removed so that the respective louver slit portions 633 and 634 can be seen. The downstream louver slit portion 633 is a slit inclined upward toward the downstream side in the ventilation direction. The upstream louver slit portion 634 is a slit inclined upward toward the upstream side in the ventilation direction. Through the louver slit portions 633 and 634, the fluid (air or water) around the corrugated fin 63 can move in the first direction. The louver slit portions 633 and 634 according to the present embodiment have the same structure as the louver slit portion described in, for example, Japanese Patent Laid-Open No. 06-147785 and are well-known structures.

[0025] In FIG. 4, in the heat exchanger 6 for an outdoor unit, a plurality of water flow paths 66 extending in the first direction are provided in the second direction, which are formed by two upstream protruding portions 632 and the ventilation direction end surface of the flat multi-hole tube 62 on the upstream side in the ventilation direction. The water flow path 66 is a path for draining the water defrosted by the corrugated fin 63. The water flow path 66 is also formed by two downstream protruding portions 631 and the ventilation direction end surface of the flat multi-hole tube 62 on the downstream side in the ventilation direction and extends in the first direction.

[0026] The corrugated fin 63 is subjected to a hydrophilic coating treatment to improve drainage. Any hydrophilic coating agent may be used, and for example, Excel Pure manufactured by Central Motor Co., Ltd. can be used.

[0027] FIG. 7 is a partial cross-sectional view of the outdoor heat exchanger 6 taken along line VII-VII of FIG. 2, showing the vicinity of the upper end of the outdoor heat exchanger 6 in the first direction. The flat multi-hole tube 62 is inserted inside the header 64 and joined by a method such as brazing in a furnace. In FIG. 7, the center of the header 64, the center of the width of the flat multi-hole tube 62 in the ventilation direction, and the center of the width of the corrugated fin 63 in the ventilation direction coincide in the ventilation direction. The width w1 of the corrugated fin 63 in the ventilation direction is less than or equal to the width of the header 64 in the ventilation direction, that is, the outer diameter d1, and is larger than the width w2 of the flat multi-hole tube 62 in the ventilation direction. That is, the lengths in the ventilation direction of the downstream protruding portion 631 and the upstream protruding portion 632 of the corrugated fin 63 are determined such that the width w1 is less than or equal to the outer diameter d1 and larger than the width w2. By making the width w1 less than or equal to the outer diameter d1, when the outdoor heat exchanger 6 is stored with the surfaces formed in the first direction and the second direction facing downward, the possibility that the corrugated fin 63 contacts the floor surface and is deformed can be suppressed. Also, by making the width w1 larger than the width w2, the space in the ventilation direction of the corrugated fin 63 can be effectively utilized.

[0028] Next, the frosting phenomenon that occurs in the outdoor heat exchanger 6 during the heating operation and the defrosting method in the present embodiment will be described. In the outdoor heat exchanger 6, since the refrigerant 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. Since the temperature of the corrugated fin 63 depends on the temperature of the refrigerant flowing through the flat multi-hole tube 62, it also becomes about -5°C. When the air passing through the corrugated fin 63 in the ventilation direction is cooled to 0°C or lower by the corrugated fin 63, the moisture in the air becomes frost or ice and adheres to the corrugated fin 63. This phenomenon is called frosting.

[0029] If frost continues to accumulate on the corrugated fins 63 due to frosting, the ventilation passage of the corrugated fins 63 will be blocked by the frost, deteriorating the heat transfer performance of the outdoor unit heat exchanger 6, and ultimately leading to a potential deterioration in the performance of the air conditioning system. To melt the frosted frost, that is, to defrost, it is common to perform a defrost operation by temporarily switching the four-way valve to circulate the high-temperature and high-pressure refrigerant on the indoor unit side to the outdoor unit side for defrosting the outdoor unit heat exchanger. In the gas heat pump type air conditioning system 1 of the present embodiment, the radiator 14 is adjacent to the outdoor unit heat exchanger 6 on the downstream side in the ventilation direction, and the corrugated fins 63 have a downstream protruding portion 631 on the downstream side in the ventilation direction, that is, on the radiator 14 side. Also, the temperature of the radiator 14 is as high as about 85°C. As a result, the heat of the radiator 14 is transmitted to the downstream protruding portion 631 of the corrugated fins 63 through the air between the radiator 14 and the outdoor unit heat exchanger 6, heating the corrugated fins 63 and defrosting the frost accumulated on the corrugated fins 63. That is, in the gas heat pump type air conditioning system 1 of the present embodiment, it is not necessary to perform the operation of switching the four-way valve, and efficient defrosting can be performed even in an air conditioning system without a four-way valve. Also, at this time, it is preferable that the outdoor unit fan 7 is not operating.

[0030] On the one hand, the melted frost becomes water, flows downward in the first direction under gravity through the respective louver slits 633 and 634 of the corrugated fin 63, and accumulates in a drain pan (not shown) separately provided in the outdoor unit 2, and is drained to the outside. Further, when the defrosting amount is large and water overflows from the respective louver slits 633 and 634, the water flows in the second direction along the inclination formed by the corrugation of the corrugated fin 63, and passes through the water flow path 66 composed of the two upstream protruding portions 632 and the flat multi-hole pipe 62, and accumulates in the drain pan (see the water flow direction f1 in FIG. 4). When a water flow is formed in the water flow path 66, the water on the corrugated fin 63 around the water flow path 66 is drawn into the flow of the water flow path 66, so that the drainage efficiency is further improved. If there is no water flow path by the upstream protruding portion, this drawing phenomenon does not occur, so the drainage efficiency is not preferable. Further, from the experimental results of a plurality of experiments by the inventor, it has been confirmed that the phenomenon of water overflowing from the respective louver slits 633 and 634 is likely to occur on the upstream side rather than the downstream side in the ventilation direction. This is because as the air is cooled as it passes through the corrugated fin 63, the temperature difference between the temperature of the air and the temperature of the corrugated fin 63 is larger on the upstream side in the ventilation direction. Accordingly, it is considered that the heat exchange amount on the upstream side in the ventilation direction increases and the amount of moisture adhering to the corrugated fin increases.

[0031] In addition, since the corrugated fin 63 of the present embodiment is subjected to a hydrophilic coating treatment, the water flowing on the corrugated fin 63 can be discharged more efficiently.

[0032] According to the gas heat pump type air conditioning system 1 according to the present embodiment, the following effects are obtained.

[0033] (1) The gas heat pump type air conditioning system 1 extends in the ventilation direction and a first direction orthogonal to the ventilation direction, and a plurality of flat multi-hole pipes 62 arranged in parallel in a second direction orthogonal to the ventilation direction and the first direction, A plurality of corrugated fins 63 are arranged side by side in the second direction between the plurality of flat multi-hole tubes 62, project to the downstream side in the ventilation direction with respect to the plurality of flat multi-hole tubes, and further extend undulating in the first direction, and an outdoor unit heat exchanger 6 provided with a compressor 5, a drive source 12 for driving the compressor 5, a radiator 14 that is adjacent to the outdoor unit heat exchanger 6 on the downstream side in the ventilation direction and cools the drive source 12, and is provided.

[0034] As a result, the frost accumulated on the corrugated fins 63 generated during the heating operation is efficiently defrosted by the heat of the radiator 14, so that deterioration of the heat transfer performance of the outdoor unit heat exchanger 6 can be suppressed.

[0035] (2) The plurality of corrugated fins 63 project to the upstream side in the ventilation direction with respect to the plurality of flat multi-hole tubes 62.

[0036] As a result, compared with the case where the corrugated fins do not project to the upstream side in the ventilation direction, the water generated by defrosting can be efficiently drained, and further, since the heat transfer rate of the corrugated fins is uniform in the ventilation direction, it is easy to exchange heat with the outside air efficiently.

[0037] (3) The outdoor unit heat exchanger 6 has columnar headers 64 connected to both ends of the plurality of flat multi-hole tubes 62 in the first direction and extending in the second direction, the width w1 of the corrugated fin 63 in the ventilation direction is less than or equal to the width d1 of the header 64 in the ventilation direction and larger than the width w2 of the flat multi-hole tube 62 in the ventilation direction.

[0038] As a result, compared with the case where the width of the corrugated fin in the ventilation direction is larger than the width of the header in the ventilation direction, the possibility that the corrugated fin contacts the floor surface and deforms can be suppressed. Also, compared with the case where the width of the corrugated fin in the ventilation direction is less than or equal to the width of the flat multi-hole tube in the ventilation direction, the space in the ventilation direction of the corrugated fin can be effectively utilized.

[0039] (4) A hydrophilic coating treatment is applied to the plurality of corrugated fins 63.

[0040] As a result, the drainage of water flowing on the corrugated fins 63 is improved, and frosting can be further suppressed.

[0041] [Second Embodiment] FIG. 8 is a perspective view similar to FIG. 4 of the heat exchanger 6a for an outdoor unit according to the second embodiment. Hereinafter, only the configurations different from those of the first embodiment will be described.

[0042] Among the corrugated fins 63 of the first embodiment, the main surfaces (that is, the protruding portions 631, 632, and the central portion 635) that constitute the surfaces facing the first direction had the louver slit portions 633, 634. However, as shown in FIG. 8, the main surface 637 of the corrugated fin 63 of the second embodiment is flat and has no holes. That is, the main surface 637 does not have the louver slit portions 633, 634.

[0043] As shown in FIG. 6, since the louver slit portions 633, 634 are inclined upward in the first direction, the flow of the fluid in the ventilation direction of the corrugated fin 63 may be obstructed by the louver slit portions 633, 634. For this reason, the moisture generated by defrosting may stay near the louver slit portions 633, 634 and may not be efficiently discharged.

[0044] Since the main surface 637 of the corrugated fin 63 of the second embodiment does not have the louver slit portions 633, 634 and is flat, the factors that obstruct the flow of water on the main surface 637 are eliminated. As a result, the water generated by defrosting can be discharged more efficiently.

[0045] Of the plurality of corrugated fins 63, no holes need to be provided only on the main surface of the lower portion in the first direction. For example, in the region within 30 mm from the lower end of the corrugated fin 63, in other words, the main surface of about 10 peaks from the lower end may be flat and may not have any holes. On the other hand, louver slit portions 633 and 634 may be provided on the main surface of the region higher than 30 mm from the lower end of the corrugated fin 63. Generally, since the liquid water generated in the frosting process flows downward in the first direction according to gravity, frosting is likely to occur in the lower corrugated fins. Therefore, by providing such a main surface in the lower portion of the corrugated fin 63, efficient defrosting and maintenance of the heat transfer rate of the corrugated fin can be achieved simultaneously.

[0046] According to the gas heat pump type air conditioning system according to the second embodiment, The plurality of corrugated fins 63 have a flat main surface 637 that constitutes the surface facing the first direction, No holes are provided in the main surface 637.

[0047] As a result, the water generated by defrosting can be discharged more efficiently.

[0048] [Third Embodiment] FIG. 9 is a perspective view similar to FIG. 4 of the outdoor unit heat exchanger 6b according to the third embodiment. Hereinafter, only the configurations different from those of the first and second embodiments will be described.

[0049] As shown in FIG. 9, drain holes 636 are provided in the main surface 637 of the corrugated fin 63. Specifically, the drain holes 636 are provided in the downstream protruding portion 631 and the upstream protruding portion 632. The shape of the drain hole 636 is substantially rectangular when viewed from the first direction. The dimensions of each side of the drain hole 636 can be set in the range of 2 mm or more so as to effectively discharge the water generated by defrosting. In the third embodiment, the dimensions of each side of the drain hole 636 are such that one side is about 7 mm and the other side is about 7 mm. With this configuration, the water generated by defrosting can be discharged even more efficiently.

[0050] Of the plurality of corrugated fins 63, drain holes 636 may be provided only on the main surface of the lower portion. For example, drain holes 636 may be provided in a region within 30 mm from the lower end of the corrugated fin 63, in other words, on the main surface of about 10 peaks from the lower end.

[0051] The plurality of corrugated fins 63 have a flat main surface 637 that constitutes a surface facing in the first direction, Drain holes 636 are provided in the main surface 637.

[0052] As a result, the water generated by defrosting can be discharged more efficiently.

[0053] [Embodiment] Next, an embodiment of a specific heat exchanger for an outdoor unit of the present disclosure will be described together with comparative examples. As shown in Table 1, Examples 1-7 and Comparative Examples 1-4 were created, and an experiment was conducted to evaluate the drainage performance of the corrugated fins. Specifically, in a posture where the first direction of the heat exchanger for an outdoor unit is the vertical direction, an experiment was conducted in which water was sprayed toward the entire core portion of the heat exchanger for an outdoor unit. When the water spraying continued, the water accumulated from the lower end of the corrugated fin to a predetermined height. When the water was sprayed further, the water did not accumulate above the predetermined height and overflowed from the corrugated fin. The predetermined height is referred to as the water retention height. That is, a high water retention height means poor drainage performance of the corrugated fin, and a low water retention height means excellent drainage performance of the corrugated fin. In this experiment, the water retention height in each example and comparative example was measured and compared.

[0054]

Table 1

[0055] Next, the configurations of each example and comparative example will be described.

[0056] [Examples 1-4] The heat exchangers for outdoor units in Examples 1-4 are formed by fixing corrugated fins with a thickness of about 0.1 mm between a plurality of flat multi-hole tubes arranged side by side at intervals of about 8 mm. The corrugated fins in Examples 1-4 have a length in the ventilation direction of 38 mm and protrude 3 mm on the upstream and downstream sides in the ventilation direction with respect to the flat multi-hole tubes. In Examples 1-4, the fin pitch (see Fig. 4) of the corrugated fins was changed from 1.2 mm to 1.6 mm. The corrugated fins in Examples 1-4 are not subjected to hydrophilic coating treatment and are not provided with drain holes. The corrugated fins in Examples 1-4 are provided with upstream and downstream louver slit portions.

[0057] [Example 5] The corrugated fin of Example 5 is obtained by applying hydrophilic coating to the corrugated fin of Example 2.

[0058] [Example 6] The corrugated fin of Example 6 has the same configuration as the corrugated fin of Example 2, except that no louver slit portion is provided. That is, the corrugated fin of Example 6 corresponds to the corrugated fin 63 of the second embodiment.

[0059] [Example 7] The corrugated fin of Example 7 is obtained by providing drain holes in the corrugated fin of Example 2. That is, the corrugated fin of Example 7 corresponds to the corrugated fin 63 of the third embodiment.

[0060] [Comparative Examples 1-4] The corrugated fins in Comparative Examples 1-4 have the same configuration as those in Examples 1-4, except that they do not protrude on the upstream and downstream sides in the ventilation direction with respect to the flat multi-hole tubes. Specifically, both ends of the corrugated fins in Comparative Examples 1-4 in the ventilation direction coincide with both ends of the flat multi-hole tubes in the ventilation direction. Therefore, the length of the corrugated fins in Comparative Examples 1-4 in the ventilation direction is 32 mm.

[0061] [Experimental Result 1] Figure 10 shows the experimental results of Comparative Examples 1-4 and Examples 1-4. The horizontal axis represents the fin pitch, and the vertical axis represents the water retention height. In Figure 10, the black circles represent the experimental results of Comparative Examples 1-4, and the black squares represent the experimental results of Examples 1-4.

[0062] At any fin pitch, the water retention height of Examples 1-4 with protrusions is lower than that of Comparative Examples 1-4 without protrusions. Also, the maximum water retention height within the range confirmed in this experiment is about 30 mm. In other words, among the corrugated fins, the range that particularly needs to improve drainage is the range from at least a height of 30 mm from the lower end of the corrugated fin.

[0063] [Experimental Result 2] Figure 11 shows the experimental results of Examples 2 and 5-7. The vertical axis represents the water retention height.

[0064] 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 fin, the water retention height is significantly reduced.

[0065] From the above experimental results, the inventors obtained the following findings. a. By protruding the corrugated fin in the ventilation direction with respect to the flat multi-hole pipe, water can be efficiently discharged. b. By applying a hydrophilic coating to the corrugated fin, water can be discharged even more efficiently. c. With the flat and hole-free main surface of the corrugated fin, water can be discharged even more efficiently. d. By providing drainage holes in the corrugated fin, water can be discharged even more efficiently. e. The water flowing through the corrugated fin accumulates up to a height of 30 mm at most from the lower end of the corrugated fin. Therefore, by applying the technology of the present disclosure to the corrugated fin in the range of at least 30 mm in height from the lower end of the corrugated fin, water can be efficiently discharged.

[0066] Note that the gas heat pump type air conditioning system according to the present disclosure is not limited to the configuration of the above embodiment, and various modifications are possible.

[0067] The outdoor heat exchanger 6 of the present embodiment is arranged in a posture where the corrugated fins 63 extend in the first direction, that is, the vertical direction. However, the corrugated fins 63 may be arranged in a posture where they extend in the second direction, that is, the horizontal direction. Note that it is preferable that the corrugated fins 63 are arranged in a posture where they extend in the vertical direction because it is easier to form a flowing water path for drainage during defrosting.

[0068] The radiator 14 of the present embodiment is adjacent to the outdoor heat exchanger 6 on the downstream side in the ventilation direction. However, the same effect can be achieved even if it is adjacent to the outdoor heat exchanger 6 on the upstream side in the ventilation direction. It is preferable that the radiator is adjacent to the outdoor heat exchanger on the downstream side in the ventilation direction because, during the cooling operation, the phenomenon that the air receives heat from the radiator before receiving heat from the outdoor heat exchanger and the heat exchange amount with the outdoor heat exchanger decreases is suppressed.

[0069] The radiator 14 of the present embodiment is arranged below the outdoor heat exchanger 6 in the first direction, but it is not limited to this position. Note that the water that could not be drained during defrosting accumulates below the outdoor heat exchanger 6 due to gravity and may freeze again. Therefore, more defrosting is required on the lower side in the first direction. For this reason, it is preferable that the radiator 14 is arranged on the lower side in the first direction.

[0070] The corrugated fins 63 of the present embodiment project downstream and upstream in the ventilation direction from the flat multi-hole pipe 62. However, even if they project only downstream in the ventilation direction from the flat multi-hole pipe 62, a sufficient defrosting effect can be achieved.

[0071] The header 64 of the present embodiment has a cylindrical shape, but it is not limited thereto. For example, it may have a quadrangular prism shape.

[0072] The hydrophilic coating may be applied only to the corrugated fins 63 or may be applied to the entire core portion 61.

[0073] The drain hole 636 may be provided at the central portion 635 of the corrugated fin 63. The drain hole 636 may also be provided only in either one of the downstream protruding portion 631 and the upstream protruding portion 632. A plurality of drain holes 636 may be provided on one main surface 637.

[0074] The upstream and downstream louver slit portions 633, 634 may not be provided in the corrugated fin 63 according to the third embodiment.

[0075] [Appendix] The gas heat pump type air conditioning system according to the present disclosure provides the following aspects.

[0076] [Aspect 1] A plurality of flat multi-hole pipes extending in the ventilation direction and in a first direction orthogonal to the ventilation direction, and arranged in parallel in a second direction orthogonal 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, protruding to the downstream side in the ventilation direction with respect to the plurality of flat multi-hole pipes, and further extending in a wavy manner in the first direction An outdoor unit heat exchanger provided with A compressor, A drive source for driving the compressor, A radiator adjacent to the downstream side in the ventilation direction with respect to the outdoor unit heat exchanger for cooling the drive source A gas heat pump type air conditioning system provided with

[0077] [Aspect 2] The plurality of corrugated fins protrude to the upstream side in the ventilation direction with respect to the plurality of flat multi-hole pipes. The gas heat pump type air conditioning system according to Aspect 1.

[0078] [Aspect 3] The outdoor unit heat exchanger is It has columnar headers that are connected to both ends of the plurality of flat multi-hole pipes in the first direction and extend in the second direction. The width of the corrugated fins in the ventilation direction is less than or equal to the width of the headers in the ventilation direction and greater than the width of the flat multi-hole pipes in the ventilation direction. The gas heat pump type air conditioning system according to aspect 1 or 2.

[0079] [Aspect 4] The plurality of corrugated fins are subjected to a hydrophilic coating treatment. The gas heat pump type air conditioning system according to any one of aspects 1 to 3.

[0080] [Aspect 5] The plurality of corrugated fins have a flat main surface that constitutes the surface facing the first direction. No holes are provided in the main surface. The gas heat pump type air conditioning system according to any one of aspects 1 to 4.

[0081] [Aspect 6] The plurality of corrugated fins have a flat main surface that constitutes the surface facing the first direction. Drain holes are provided in the main surface. The gas heat pump type air conditioning system according to any one of aspects 1 to 4.

Explanation of Signs

[0082] 1: Gas heat pump type air conditioning system 2: Outdoor unit 5: Compressor 6, 6a, 6b: Heat exchangers for outdoor units 62: Flat multi-hole pipe 63: Corrugated fin 631: Downstream protruding part 632: Upstream protruding part 633: Downstream louver slit part 634: Upstream louver slit part 635: Central part 636: Drain hole 637: Main surface 64: Header 14: Radiator d1: Header outer diameter w1: Ventilation direction width of corrugated fin w2: Ventilation direction width of flat multi-hole pipe

Claims

1. A plurality of flat multi-hole tubes extending in a first direction perpendicular to the ventilation direction and arranged in parallel 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 tubes, protruding downstream in the ventilation direction relative to the plurality of flat multi-hole tubes, and extending in a wavy manner in the first direction; An outdoor unit heat exchanger comprising: A compressor; A drive source that drives the compressor; a radiator adjacent to the outdoor unit heat exchanger on the downstream side in the ventilation direction and configured to cool the driving source; A gas heat pump air conditioning system equipped with

2. The corrugated fins protrude upstream in the ventilation direction relative to the flat multi-hole tubes.

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

3. The outdoor unit heat exchanger comprises: a columnar header connected to both ends of the flat multi-hole tubes in the first direction and extending in the second direction; The width of the corrugated fin in the ventilation direction is equal to or smaller than the width of the header in the ventilation direction and is larger than the width of the flat multi-hole pipe in the ventilation direction.

3. A gas heat pump air conditioning system according to claim 1 or 2.

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

3. A gas heat pump air conditioning system according to claim 1 or 2.

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

3. A gas heat pump air conditioning system according to claim 1 or 2.

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

3. A gas heat pump air conditioning system according to claim 1 or 2.

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