WO2019180817A1 - Heat exchanger, refrigeration cycle device, and air conditioning device - Google Patents

Abstract

This heat exchanger comprises a heat exchanger body having: a heat transmission pipe through which a fluid passes and which has a groove formed in the inner surface thereof, the groove being a recess spirally extending in the direction of the pipe axis; and a fin that is in contact with the heat transmission pipe to promote heat exchange of the fluid. If a flow path length L, which is the length of the heat transmission pipe, from the heat exchanger inlet to the heat exchanger outlet between which the fluid flows, is not greater than 10 m, the lead angle θ formed between the pipe axis and the groove satisfies 25°≤θ≤45°, and if the flow path length L is greater than 10 m, the lead angle θ satisfies 5°≤θ<25°.

Description

Heat exchanger, refrigeration cycle apparatus and air conditioner

The present invention relates to a heat exchanger that performs heat exchange, a refrigeration cycle apparatus, and an air conditioner. In particular, the present invention relates to a heat exchanger having a heat transfer tube provided with a groove on the inner surface of the tube.

Conventionally, in a heat exchanger used in a refrigeration cycle apparatus such as a refrigeration apparatus, an air conditioner, or a heat pump, generally, an inner surface is formed so as to penetrate through holes provided in each fin with respect to fins arranged in plural at a predetermined interval. A heat transfer tube in which a groove is formed is disposed. The heat transfer tube becomes a part of a refrigerant circuit in the refrigeration cycle apparatus, and a fluid such as a refrigerant flows inside. Hereinafter, description will be made assuming that the refrigerant is a fluid.

And the refrigerant flowing through such a heat transfer tube undergoes phase change (condensation or evaporation) by heat exchange with air flowing outside the heat transfer tube. In order to perform phase change efficiently, grooves based on the set parameters are formed, and heat transfer of the heat transfer tube is achieved by increasing the surface area in the tube, the effect of fluid agitation due to the groove, and the effect of holding the liquid film between the grooves due to the capillary action of the groove. The performance is improved (for example, refer to Patent Document 1).

JP 2004-301495 A

However, the groove in the heat transfer tube of Patent Document 1 described above does not have a shape corresponding to the flow path in the heat transfer tube. For this reason, when the heat exchanger is mounted at a high density, the performance may be lowered.

OBJECT OF THE INVENTION In order to solve the above-described problems, an object of the present invention is to provide a heat exchanger, a refrigeration cycle apparatus, and an air conditioner having specifications that match a flow path in a heat transfer tube.

The heat exchanger according to the present invention includes a heat transfer tube having a groove that is a spiral recess in the tube axis direction on the tube inner surface through which the fluid passes, and a fin that contacts the heat transfer tube and promotes heat exchange of the fluid. In a flow path length L of a heat transfer tube in which the fluid passes between the inlet of the heat exchanger and the outlet of the heat exchanger, where L ≦ 10 m, the tube axis And the groove has a groove where the lead angle θ is 25 ° ≦ θ ≦ 45 °, and in the flow path where L> 10 m, the groove has a groove where 5 ° ≦ θ <25 °.

According to the heat exchanger of the present invention, since the heat transfer tube has a groove lead angle different depending on the flow path length L from the heat exchanger inlet to the heat exchanger outlet, It can be a heat exchanger with suitable specifications. And the efficiency of heat exchange can be improved and the APF (Annual Performance Factor) in the air conditioner can be increased.

It is the schematic which shows the structure of the heat exchanger 1 which concerns on Embodiment 1 of this invention. It is the schematic which shows the structure of the heat exchanger main body 10 which concerns on Embodiment 1 of this invention. In the heat exchanger 1 which concerns on Embodiment 1 of this invention, it is a figure explaining the inner surface of the heat exchanger tube 12 in the direction parallel to the direction of a pipe axis. In the heat exchanger 1 which concerns on Embodiment 1 of this invention, it is a figure explaining the inner surface of the heat exchanger tube 12 in the direction orthogonal to the direction of a pipe axis. It is a figure which shows the correlation with the lead angle (theta) of the heat exchanger tube 12, and the performance of the heat exchanger tube 12 which concern on Embodiment 1 of this invention. It is the schematic which shows the correlation with lead angle (theta) and APF of the heat exchanger tube 12 which concerns on Embodiment 1 of this invention. It is a figure which shows the correlation with the groove height h of the heat exchanger tube 12 which concerns on Embodiment 2 of this invention, and the performance in the heat exchanger tube 12. FIG. It is the schematic which shows the correlation with the groove height h and APF of the heat exchanger tube 12 which concerns on Embodiment 2 of this invention. It is a figure which shows the structure of the refrigerating-cycle apparatus which concerns on Embodiment 3 of this invention.

Hereinafter, a heat exchanger according to an embodiment of the invention will be described with reference to the drawings. In the following drawings, the same reference numerals denote the same or corresponding parts, and are common to the whole text of the embodiments described below. In the drawings, the size relationship of each component may be different from the actual one. And the form of the component represented by the whole specification is an illustration to the last, Comprising: It does not limit to the form described in the specification. In particular, the combination of the components is not limited to the combination in each embodiment, and the components described in the other embodiments can be applied to another embodiment. In addition, the level of pressure, temperature, etc. is not particularly determined in relation to absolute values, but is relatively determined in terms of the state and operation of the apparatus. In addition, when there is no need to distinguish or identify a plurality of similar devices that are distinguished by subscripts, the subscripts may be omitted.

Embodiment 1 FIG.
<Configuration of Heat Exchanger 1 of Embodiment 1>
FIG. 1 is a schematic diagram showing a configuration of a heat exchanger 1 according to Embodiment 1 of the present invention. In FIG. 1, a heat exchanger 1 is a fin-tube heat exchanger that includes a plurality of heat exchanger bodies 10 and flow passage pipes 20. As will be described later, heat exchange between the refrigerant passing through the heat transfer tube 12 and the air passing between the plurality of fins 11 is performed in the heat exchanger body 10 with respect to the refrigerant flowing in from the heat exchanger inlet 1A. . The heat-exchanged refrigerant flows out from the heat exchanger outlet 1B. The channel pipe 20 is a pipe that connects the plurality of heat exchanger bodies 10 and serves as a refrigerant channel. The channel pipe 20 is a pipe having a plurality of branch numbers such as one pipe, a T-shaped pipe, and a bulge three-way pipe.

FIG. 2 is a schematic diagram showing the configuration of the heat exchanger body 10 according to Embodiment 1 of the present invention. The heat exchanger body 10 includes a plurality of fins 11 and heat transfer tubes 12. The fins 11 are, for example, substantially rectangular plate-like fins that are arranged at regular intervals. Each fin 11 has a through hole so as to intersect and contact the heat transfer tube 12. As will be described later, the heat transfer tube 12 becomes a part of the flow path in the refrigerant circuit in the refrigeration cycle apparatus, and the refrigerant flows inside the tube. The heat of the refrigerant flowing inside the heat transfer tube 12 and the air flowing outside is transmitted to the fin 11. The fins 11 increase the heat transfer area and can efficiently perform heat exchange between the refrigerant and the air.

FIG. 3 is a view for explaining the inner surface of the heat transfer tube 12 in the direction parallel to the direction of the tube axis 15 in the heat exchanger 1 according to Embodiment 1 of the present invention. Moreover, FIG. 4 is a figure explaining the inner surface of the heat exchanger tube 12 in the direction orthogonal to the direction of the tube axis | shaft 15 in the heat exchanger 1 which concerns on Embodiment 1 of this invention.

The heat transfer tube 12 of the heat exchanger 1 in Embodiment 1 has a plurality of grooves 14 in which concave portions are spirally formed on the tube inner surface side. The groove 14 serves as a flow path for a refrigerant that is a fluid. The grooves 14 can increase the surface area of the inner surface of the heat transfer tube 12, stir the fluid, hold a liquid film by capillary action, and promote heat transfer between the heat transfer tube 12 and the refrigerant flowing in the heat transfer tube 12. . The groove 14 is processed on the inner surface of the heat transfer tube 12 so that the direction of the tube axis 15 and the direction in which the spiral groove 14 extends form a certain angle. This angle is hereinafter referred to as a lead angle θ. Here, by forming the grooves 14, the inner surface of the tube is uneven. Although the concave portion becomes the groove 14, as described later, in the first embodiment, the height of the convex portion is the groove height h of the groove 14.

Next, the relationship between the lead angle θ of the heat transfer tube 12 and the flow path length L by the heat transfer tube 12 in the heat exchanger 1 of the first embodiment will be described. In the heat exchanger 1 of Embodiment 1, the lead angle θ of the groove 14 is 25 ° ≦ θ ≦ 45 ° in the heat transfer tube 12 where L ≦ 10 m with respect to a certain flow path length L. The heat transfer tube 12 is used. Further, for the heat transfer tube 12 where L> 10 m, the heat transfer tube 12 in which the lead angle θ of the groove 14 satisfies 5 ° ≦ θ <25 ° is used. Here, between the heat exchanger inlet 1A and the heat exchanger outlet 1B, the length of the heat transfer tube 12 through which the refrigerant passes becomes the flow path length L. In FIG. 1, the sum of the lengths L1, L2 and L3 of the heat transfer tubes 12 of the heat exchanger body 10 in the path of the flow path pipe 20 indicated by a thick line is the flow path length L.

<Effect of Embodiment 1>
FIG. 5 is a diagram showing a correlation between the lead angle θ of the heat transfer tube 12 and the performance of the heat transfer tube 12 according to Embodiment 1 of the present invention. In FIG. 5, the performance of the heat transfer tube 12 is represented by the in-tube heat transfer coefficient αi. When the amount of refrigerant flowing through the heat transfer tube 12 is constant, the heat transfer coefficient αi in the tube increases while converging as the lead angle θ increases. Further, the in-pipe refrigerant pressure loss ΔPref increases monotonously. In general, the efficiency is better when the heat transfer coefficient αi in the pipe is larger and the refrigerant pressure loss ΔPref in the pipe is smaller. Therefore, the optimal shape of the groove 14 exists depending on the form of the heat exchanger 1.

FIG. 6 is a schematic diagram showing the correlation between the lead angle θ and the APF of the heat transfer tube 12 according to Embodiment 1 of the present invention. APF (Annual Performance Factor) is an index that indicates the performance of an air conditioner during year-round use. Regarding the flow path length L, the longer the flow path length L, the greater the influence of the refrigerant pressure loss ΔPref in the pipe. As described above, when the lead angle θ is small, the refrigerant pressure loss ΔPref in the pipe is small. Therefore, when the lead angle θ is small, the APF tends to be improved. Conversely, the shorter the flow path length L, the greater the influence of the in-tube heat transfer coefficient αi. As described above, when the lead angle θ is large, the in-tube heat transfer coefficient αi is large. Therefore, when the lead angle θ is increased, the APF tends to be improved.

As shown in FIG. 6, for example, in a room air conditioner test, when the flow path length L is divided into L ≦ 10 m and L> 10 m, the APF threshold is set at a lead angle θ of 25 °. Exists. Therefore, when the flow path length L is L ≦ 10 m, the lead angle θ of the groove 14 is 25 ° ≦ θ ≦ 45 °, and when L> 10 m, the lead angle θ is 5 °. It is preferable to use the heat transfer tube 12 of ° ≦ θ <25 °.

In general, the smaller the outer diameter of the heat transfer tube 12, the smaller the inner diameter. Accordingly, the refrigerant pressure loss ΔPref in the pipe increases as the outer diameter of the heat transfer tube 12 decreases, so that the inner diameter decreases. For example, in a room air conditioner, currently, a heat transfer tube having an outer diameter of φ7.0 or φ6.35 is often used, but the heat transfer tube 12 of Embodiment 1 maintains the refrigerant pressure loss ΔPref in the tube, The outer diameter and inner diameter can be reduced. For example, compared to a heat transfer tube having an outer diameter of φ7.0, the heat transfer tube 12 having an outer diameter of φ5.0 or less, in which the refrigerant pressure loss ΔPref in the tube is about twice or more can be used. Further, by reducing the diameter of the heat transfer tube 12, the volume in the tube can be reduced. Therefore, the amount of refrigerant required for the entire refrigerant circuit can be reduced. In particular, when a flammable refrigerant is used, the safety of the apparatus can be further improved by reducing the refrigerant.

As described above, according to the heat exchanger 1 of the first embodiment, the heat transfer tube 12 through which the refrigerant passes, the flow path length L of the heat transfer tube 12, and L ≦ 10 m, the lead angle θ in the groove 14. However, the heat exchanger 1 using the heat transfer tube 12 satisfying 25 ° ≦ θ ≦ 45 ° is configured. Further, when L> 10 m, the heat exchanger 1 using the heat transfer tube 12 in which the lead angle θ in the groove 14 satisfies 5 ° ≦ θ <25 ° is configured. For this reason, APF in an air conditioning apparatus can be made high.

Embodiment 2. FIG.
<Configuration of Embodiment 2>
The second embodiment will be described focusing on differences from the heat transfer tube 12 of the first embodiment. The heat transfer tube 12 of the second embodiment has basically the same configuration as the heat transfer tube 12 described in the first embodiment, and has a plurality of spiral grooves 14 on the inner surface. Here, in Embodiment 1, the groove height h of the groove 14 is not particularly mentioned. In the heat transfer tube 12 of the second embodiment, the groove height h of the groove 14 on the inner surface is such that h ≧ 0.06 mm when L ≦ 10 m, and 0.06 mm <h when L> 10 m. .

<Effect of Embodiment 2>
FIG. 7 is a diagram showing a correlation between the groove height h of the heat transfer tube 12 and the performance in the heat transfer tube 12 according to the second embodiment of the present invention. In FIG. 7, the performance of the heat transfer tube 12 is represented by the in-tube heat transfer coefficient αi. When the groove height h increases when the amount of refrigerant flowing through the heat transfer tube 12 is constant, the in-tube heat transfer coefficient αi increases while converging. Further, the in-pipe refrigerant pressure loss ΔPref increases monotonously. As described in the first embodiment, the efficiency is generally better when the in-tube heat transfer coefficient αi is larger and the in-tube refrigerant pressure loss ΔPref is smaller.

FIG. 8 is a schematic diagram showing the correlation between the groove height h of the heat transfer tube 12 and the APF according to Embodiment 2 of the present invention. As described in the first embodiment, the longer the flow path length L, the greater the influence of the refrigerant pressure loss ΔPref in the pipe. Therefore, in this case, when the groove height h is small, the APF tends to be improved. Conversely, the shorter the flow path length L, the greater the influence of the in-tube heat transfer coefficient αi. Therefore, in this case, when the groove height h is large, the APF tends to be improved.

As shown in FIG. 8, for example, in a room air conditioner test, when the flow path length L is divided into L ≦ 10 m and L> 10 m, the groove height h is 0.06 mm. There is a threshold. For this reason, when the flow path length L is L ≦ 10 m, the groove height h of the groove 14 is the heat transfer tube 12 with h ≧ 0.06 mm, and when L> 10 m, 0. It is preferable to use the heat transfer tube 12 of 06 <h.

As described above, in the heat exchanger 1 of the second embodiment, for the groove height h in the groove 14 on the inner surface of the heat transfer tube 12, when the flow path length L is L ≦ 10 m, h ≧ 0.06 mm. In the case of L> 10 m, the heat transfer tube 12 is 0.06 <h. For this reason, APF in an air conditioning apparatus can be made high. Further, by reducing the diameter of the heat transfer tube 12 and reducing the volume in the tube, the amount of refrigerant required in the entire refrigerant circuit can be reduced. In particular, when a flammable refrigerant is used, the safety of the apparatus can be further improved by reducing the refrigerant. Here, the groove 14 may be a combination of the condition related to the lead angle θ described in the first embodiment and the condition of the groove height h of the groove 14 in the second embodiment.

Embodiment 3 FIG.
FIG. 9 is a diagram showing a configuration of a refrigeration cycle apparatus according to Embodiment 3 of the present invention. Here, as an example of the refrigeration cycle apparatus, an air conditioner 50 that cools and heats a target space will be described. The air conditioner performs the steps of evaporation, compression, condensation, and expansion on the refrigerant, circulates the refrigerant while changing the phase from liquid to gas, and from gas to liquid, and transfers heat to the refrigerant. Air conditioning of the space.

9 has an outdoor unit (outdoor unit) 200 and an indoor unit (indoor unit) 100. The compressor 210, the four-way valve 220, the heat source side heat exchanger 230 and the expansion device 240 included in the outdoor unit 200, and the load side heat exchanger 110 included in the indoor unit 100 are connected by a gas refrigerant pipe 300 and a liquid refrigerant pipe 400. Thus, a refrigerant circulation circuit is formed. Here, in FIG. 9, the refrigerant flow during the cooling operation is indicated by a solid arrow, and the refrigerant flow during the heating operation is indicated by a dotted arrow.

The outdoor unit 200 includes a compressor 210, a four-way valve 220, a heat source side heat exchanger 230, an expansion device 240, and a heat source side blower 250. The compressor 210 compresses and discharges the sucked refrigerant. Here, although not particularly limited, the capacity of the compressor 210 (the amount of refrigerant sent out per unit time) may be changed by arbitrarily changing the operation frequency by using, for example, an inverter circuit. The four-way valve 220 is a valve that switches the flow of the refrigerant between, for example, a cooling operation and a heating operation.

The heat source side heat exchanger 230 in Embodiment 3 performs heat exchange between the refrigerant and air (outdoor air). For example, it functions as an evaporator during heating operation, evaporating and evaporating the refrigerant. Moreover, it functions as a condenser during the cooling operation, and condenses and liquefies the refrigerant. The heat source side blower 250 sends air into the heat source side heat exchanger 230. The heat source side blower 250 is controlled by the control device 60A.

A throttling device 240 such as an expansion valve (flow rate control means) decompresses the refrigerant to expand it. For example, in the case of an electronic expansion valve or the like, the opening degree is adjusted based on an instruction from the control device 60A.

Moreover, the indoor unit 100 has a load side heat exchanger 110 and a load side blower 120. For example, the load-side heat exchanger 110 performs heat exchange between air to be air-conditioned and a refrigerant. During heating operation, it functions as a condenser and condenses and liquefies the refrigerant. Moreover, it functions as an evaporator during cooling operation, evaporating and evaporating the refrigerant. Here, the heat exchanger 1 in Embodiment 1 and Embodiment 2 is used for the load-side heat exchanger 110. However, it is not limited to the load side heat exchanger 110, but may be used for the heat source side heat exchanger 230, and is used for at least one of the heat exchangers 1 serving as a condenser and an evaporator. By using the heat exchanger 1 for the load-side heat exchanger 110, it is possible to provide a high-performance air conditioner with good heat exchange efficiency. Further, the load side blower 120 sends air into the load side heat exchanger 110. The load-side fan 120 is controlled by the control device 60A.

For example, the compressor 210, the four-way valve 220, the expansion device 240, the heat source side blower 250, the load side blower 120, various sensors, and the like are connected to the control device 60A and the control device 60B. The control device 60A and the control device 60B control operations of devices such as the compressor 210 based on signals sent from various sensors. By switching the flow path of the four-way valve 220 by the control device 60A and the control device 60B, the cooling operation and the heating operation are switched.

First, the flow of the refrigerant during the cooling operation in the air conditioner 50 will be described. The high-pressure and high-temperature gaseous refrigerant discharged from the compressor 210 flows into the heat source side heat exchanger 230 via the four-way valve 220 and condenses by heat exchange with the outside air supplied by the heat source side blower 250. Thus, the refrigerant becomes a high-pressure liquid state and flows out of the heat source side heat exchanger 230. The high-pressure liquid refrigerant flowing out of the heat source side heat exchanger 230 flows into the expansion device 240 and becomes a low-pressure gas-liquid two-phase refrigerant. The low-pressure gas-liquid two-phase refrigerant flowing out of the expansion device 240 flows into the load-side heat exchanger 110 and evaporates by heat exchange with the indoor air supplied by the load-side fan 120, thereby causing a low-pressure gas state. And flows out of the load-side heat exchanger 110. The low-pressure gaseous refrigerant flowing out from the load-side heat exchanger 110 is sucked into the compressor 210 through the four-way valve 220.

Next, the refrigerant flow during the heating operation in the air conditioner 50 will be described. The high-pressure and high-temperature gas refrigerant discharged from the compressor 210 flows into the load-side heat exchanger 110 via the four-way valve 220. In the load-side heat exchanger 110, the refrigerant is condensed by heat exchange with room air supplied by the load-side fan 120, thereby becoming a high-pressure liquid refrigerant and flows out of the load-side heat exchanger 110. The high-pressure liquid refrigerant flowing out of the load-side heat exchanger 110 flows into the expansion device 240 and becomes a low-pressure gas-liquid two-phase refrigerant. The low-pressure gas-liquid two-phase refrigerant flowing out of the expansion device 240 flows into the heat source side heat exchanger 230 and evaporates by heat exchange with the outside air supplied by the heat source side blower 250, whereby the low pressure gas refrigerant. And flows out of the heat source side heat exchanger 230. The low-pressure gaseous refrigerant flowing out from the heat source side heat exchanger 230 is sucked into the compressor 210 via the four-way valve 220.

As the refrigerating machine oil used in the compressor 210, it is preferable to use an incompatible oil having incompatibility such as HAB oil, for example, from the viewpoint of melting of the refrigerant and replacement. Here, in order to reduce the remaining amount of the refrigerating machine oil in the heat exchanger heat transfer tube, it is preferable to use the heat transfer tube 12 having a low pressure loss in the tube. Therefore, by using the heat exchanger 1 according to the first embodiment and the second embodiment, it is possible to provide the air conditioner 50 that can ensure high quality with high performance.

Further, as a refrigerant used in the air conditioner 50, an R32 refrigerant is generally used in a room air conditioner. Here, considering the environment and the like, it is preferable to use a refrigerant having a lower GWP (global warming potential). For example, R290 can be cited as a candidate. However, R290 has a larger refrigerant pressure loss ΔPref in the pipe than R32. Moreover, since R290 is a highly flammable refrigerant, there is a possibility that it will burn if the amount enclosed is large. Therefore, the heat exchanger 1 described in the first embodiment and the second embodiment described above can compensate for the loss due to the refrigerant pressure loss ΔPref in the pipe due to R290. Furthermore, since the heat exchanger 1 can reduce the pipe internal volume in the unit, the amount of refrigerant can be reduced. Therefore, it is possible to provide a refrigeration cycle apparatus that can ensure high performance and quality.

1 Heat Exchanger, 1A Heat Exchanger Inlet, 1B Heat Exchanger Outlet, 10 Heat Exchanger Body, 11 Plate Fin, 12 Heat Transfer Tube, 14 Groove, 15 Tube Shaft, 20 Channel Piping, 50 Air Conditioner , 60A, 60B control device, 100 indoor unit, 110 load side heat exchanger, 120 load side blower, 200 outdoor unit, 210 compressor, 220 four-way valve, 230 heat source side heat exchanger, 240 expansion device, 250 heat source side blower 300 gas refrigerant piping, 400 liquid refrigerant piping.

Claims (9)

A heat transfer tube having a groove that forms a spiral recess in the tube axis direction on the tube inner surface through which the fluid passes;
A heat exchanger body having fins that come into contact with the heat transfer tubes and promote heat exchange of the fluid;
When the flow path length L of the heat transfer tube through which the fluid passes from the heat exchanger inlet to the heat exchanger outlet is L ≦ 10 m, the lead angle formed by the tube axis and the groove A heat exchanger having the groove where θ is 25 ° ≦ θ ≦ 45 ° and having the groove where 5 ° ≦ θ <25 ° in a flow path of L> 10 m. When the flow path length L from the heat exchanger inlet to the heat exchanger outlet is L ≦ 10 m, the groove height h in the groove of the heat transfer tube is h ≧ 0.06 mm. 2. The heat exchanger according to claim 1, wherein the groove has h <0.06 mm in a flow path of L> 10 m. A heat transfer tube having a groove that forms a spiral recess in the tube axis direction on the tube inner surface through which the fluid passes;
A heat exchanger body having fins that come into contact with the heat transfer tubes and promote heat exchange of the fluid;
When the flow path length L of the heat transfer tube through which the fluid passes from the heat exchanger inlet to the heat exchanger outlet is L ≦ 10 m, the groove height in the groove of the heat transfer tube h is a heat exchanger having the groove satisfying h ≧ 0.06 mm and having the groove satisfying h <0.06 mm in a flow path of L> 10 m. The heat exchanger according to any one of claims 1 to 3, wherein an outer diameter of the heat transfer tube is 5.0 or less. The heat exchange according to any one of claims 1 to 4, further comprising a channel pipe that pipe-connects the plurality of heat exchanger bodies from the heat exchanger inlet to the heat exchanger outlet. vessel. Piping includes a compressor that compresses the sucked refrigerant, a condenser that condenses the refrigerant by heat exchange, a throttling device that depressurizes the condensed refrigerant, and an evaporator that evaporates the decompressed refrigerant by heat exchange. Configure a refrigerant circuit to connect and circulate the refrigerant;
A refrigeration cycle apparatus using the heat exchanger according to any one of claims 1 to 5 for at least one of the condenser and the evaporator. The refrigeration cycle apparatus according to claim 6, wherein the refrigerating machine oil is oil having incompatibility with the refrigerant. The refrigeration cycle apparatus according to claim 6 or 7, wherein the refrigerant is R290. An air conditioner that cools and heats a target space by the refrigeration cycle apparatus according to any one of claims 6 to 8.

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