WO2021234964A1

WO2021234964A1 - Heat exchanger and air conditioner

Info

Publication number: WO2021234964A1
Application number: PCT/JP2020/020357
Authority: WO
Inventors: 理人足立; 洋次尾中; 哲二七種
Original assignee: 三菱電機株式会社
Priority date: 2020-05-22
Filing date: 2020-05-22
Publication date: 2021-11-25
Also published as: JPWO2021234964A1; US20230101157A1; CN115516269A; EP4155652A1; JP7292510B2; EP4155652A4

Abstract

A heat exchanger is provided with a plurality of flat tubes within which a refrigerant flows, and a plurality of fins that are provided between the flat tubes and that transfer the heat of the refrigerant flowing through the flat tubes. The airflow-direction upstream-side end part of the flat tubes is at the same position as the upstream-side end part of the fins or projects beyond the upstream-side end part of the fins. An opening is formed at the upstream-side end part of the flat tubes or the upstream-side end part of the fins.

Description

Heat exchanger and air conditioner

The present disclosure relates to a heat exchanger and an air conditioner provided with a flat tube and fins.

Conventionally, a heat exchanger equipped with a flat tube and fins is known. Patent Document 1 discloses a heat exchanger including a plurality of flat tubes and corrugated fins provided with a plurality of louvers. In Patent Document 1, the upstream end of the air flow of the fin is an extension portion protruding from the upstream end of the flat tube. In general, the air exchanged heat on the upstream side of the fin is deprived of heat or cold heat by the amount of heat exchanged, so that the amount of heat exchange on the downstream side is reduced. In Patent Document 1, since the upstream end of the fin protrudes from the upstream end of the flat tube, the area of contact between the fin and the flat tube on the upstream side is small. As a result, Patent Document 1 attempts to reduce the amount of heat exchange on the upstream side, suppress the decrease in the amount of heat exchange on the downstream side, and balance the amount of heat exchange on the upstream side with the amount of heat exchange on the downstream side. It is a thing.

Japanese Patent No. 5563162

However, in the heat exchanger disclosed in Patent Document 1, the strength of the fin is lowered because the upstream end of the fin protrudes from the upstream end of the flat tube.

The present disclosure has been made to solve the above-mentioned problems, and is a heat exchanger and air that secures the strength of fins while balancing the amount of heat exchange on the upstream side and the amount of heat exchange on the downstream side. It provides a harmonizer.

The heat exchanger according to the present disclosure includes a plurality of flat pipes through which a refrigerant flows, and a plurality of fins provided between the flat pipes to transfer the heat of the refrigerant flowing through the flat pipes. The upstream end of the air flow is co-located with the upstream end of the fin or protrudes from the upstream end of the fin and is the upstream end of the flat tube or the upstream end of the fin. An opening is formed in.

According to the present disclosure, the upstream end of the air flow in the flat tube is at the same position as the upstream end of the fin or protrudes from the upstream end of the fin. Therefore, the strength of the fins can be ensured. An opening is formed at the upstream end of the flat tube or the upstream end of the fin. As a result, it is possible to balance the amount of heat exchange on the upstream side and the amount of heat exchange on the downstream side of the fin. That is, the strength of the fins can be ensured while balancing the amount of heat exchange on the upstream side and the amount of heat exchange on the downstream side.

It is a circuit diagram which shows the air conditioner which concerns on Embodiment 1. FIG. It is a front view which shows the heat exchanger which concerns on Embodiment 1. FIG. It is sectional drawing which shows the flat tube and fin which concerns on Embodiment 1. FIG. It is sectional drawing which shows the flat tube and fin which concerns on Embodiment 2. FIG. It is sectional drawing which shows the flat tube and fin which concerns on Embodiment 3. FIG. It is sectional drawing which shows the flat tube and fin which concerns on Embodiment 3. FIG. It is sectional drawing which shows the flat tube and fin which concerns on the modification of Embodiment 3. It is sectional drawing which shows the flat tube and fin which concerns on Embodiment 4. FIG. It is a front view which shows the heat exchanger which concerns on Embodiment 5. It is sectional drawing which shows the flat tube and fin which concerns on Embodiment 5. FIG. It is sectional drawing which shows the flat tube and fin which concerns on the modification of Embodiment 5. It is sectional drawing which shows the flat tube and fin which concerns on Embodiment 6.

Hereinafter, embodiments of the heat exchanger and air conditioner of the present disclosure will be described with reference to the drawings. The present disclosure is not limited to the embodiments described below. Further, in the following drawings including FIG. 1, the relationship between the sizes of the constituent members may differ from the actual one. In addition, in the following description, terms indicating directions are appropriately used to facilitate understanding of the present disclosure, but these terms are for the purpose of explaining the present disclosure, and these terms are intended to limit the present disclosure. is not it. Examples of the term indicating the direction include "top", "bottom", "right", "left", "front", "rear", and the like. In some drawings, the hatching of the cross-sectional view is partially omitted.

Embodiment 1.
FIG. 1 is a circuit diagram showing an air conditioner 1 according to the first embodiment. As shown in FIG. 1, the air conditioner 1 is a device for adjusting the air in the indoor space, and includes an outdoor unit 2 and an indoor unit 3 connected to the outdoor unit 2. The outdoor unit 2 is provided with a compressor 6, a flow path switching device 7, a heat exchanger 8, an outdoor blower 9, and an expansion unit 10. The indoor unit 3 is provided with an indoor heat exchanger 11 and an indoor blower 12.

A compressor 6, a flow path switching device 7, a heat exchanger 8, an expansion unit 10, and an indoor heat exchanger 11 are connected by a refrigerant pipe 5, and a refrigerant circuit 4 through which a refrigerant as a working gas flows is configured. The compressor 6 sucks in a refrigerant in a low temperature and low pressure state, compresses the sucked refrigerant into a refrigerant in a high temperature and high pressure state, and discharges the sucked refrigerant. The flow path switching device 7 switches the direction in which the refrigerant flows in the refrigerant circuit 4, and is, for example, a four-way valve. The heat exchanger 8 exchanges heat between, for example, outdoor air and a refrigerant. The heat exchanger 8 acts as a condenser during the cooling operation and as an evaporator during the heating operation.

The outdoor blower 9 is a device that sends outdoor air to the heat exchanger 8. The expansion unit 10 is a pressure reducing valve or an expansion valve that decompresses and expands the refrigerant. The expansion unit 10 is, for example, an electronic expansion valve whose opening degree is adjusted. The indoor heat exchanger 11 exchanges heat between, for example, indoor air and a refrigerant. The indoor heat exchanger 11 acts as an evaporator during the cooling operation and as a condenser during the heating operation. The indoor blower 12 is a device that sends indoor air to the indoor heat exchanger 11.

(Operation mode, cooling operation)
Next, the operation mode of the air conditioner 1 will be described. First, the cooling operation will be described. In the cooling operation, the refrigerant sucked into the compressor 6 is compressed by the compressor 6 and discharged in a high temperature and high pressure gas state. The high-temperature and high-pressure gas-state refrigerant discharged from the compressor 6 passes through the flow path switching device 7 and flows into the heat exchanger 8 acting as a condenser, and in the heat exchanger 8, the outdoor blower 9 causes the refrigerant to flow into the heat exchanger 8. It exchanges heat with the sent outdoor air, condenses and liquefies. The condensed liquid-state refrigerant flows into the expansion unit 10 and is expanded and depressurized in the expansion unit 10 to become a low-temperature and low-pressure gas-liquid two-phase state refrigerant. Then, the refrigerant in the gas-liquid two-phase state flows into the indoor heat exchanger 11 that acts as an evaporator, and in the indoor heat exchanger 11, heat is exchanged with the indoor air sent by the indoor blower 12, and is evaporated and gasified. do. At this time, the indoor air is cooled, and cooling is performed indoors. The evaporated low-temperature and low-pressure gas-state refrigerant passes through the flow path switching device 7 and is sucked into the compressor 6.

(Operation mode, heating operation)
Next, the heating operation will be described. In the heating operation, the refrigerant sucked into the compressor 6 is compressed by the compressor 6 and discharged in a high temperature and high pressure gas state. The high-temperature and high-pressure gas-state refrigerant discharged from the compressor 6 passes through the flow path switching device 7 and flows into the indoor heat exchanger 11 acting as a condenser, and in the indoor heat exchanger 11, the indoor blower. It exchanges heat with the indoor air sent by No. 12, condenses and liquefies. At this time, the indoor air is warmed and heating is performed in the room. The condensed liquid-state refrigerant flows into the expansion unit 10 and is expanded and depressurized in the expansion unit 10 to become a low-temperature and low-pressure gas-liquid two-phase state refrigerant. Then, the refrigerant in the gas-liquid two-phase state flows into the heat exchanger 8 that acts as an evaporator, and in the heat exchanger 8, heat is exchanged with the outdoor air sent by the outdoor blower 9 to evaporate and gasify. The evaporated low-temperature and low-pressure gas-state refrigerant passes through the flow path switching device 7 and is sucked into the compressor 6.

FIG. 2 is a front view showing the heat exchanger 8 according to the first embodiment. Next, the heat exchanger 8 will be described in detail. As shown in FIG. 2, the heat exchanger 8 is, for example, a parallel flow type heat exchanger 8. The heat exchanger 8 may be a fin tube type heat exchanger. The heat exchanger 8 includes a flat tube 20, fins 30, and a header 40. The flat tube 20 is a tube through which a refrigerant flows, and a plurality of the flat tubes 20 are arranged and made of aluminum or an aluminum alloy. Further, the flat tube 20 may use a clad material having aluminum as a core material. The flat tube 20 is formed, for example, in which a plurality of flow paths 21 (see FIG. 3) through which a refrigerant flows are formed in a row.

The fin 30 is a member that transfers the heat of the refrigerant flowing through the flat pipe 20, and is, for example, a corrugated fin that is bent and arranged between the flat pipe 20 and the flat pipe 20. The fins 30 have an inclined surface 30a that is inclined with respect to the horizontal direction (see FIG. 3), and are alternately folded back. Between the fin 30 and the flat tube 20, there is a ventilation passage 31 through which air flows. The fin 30 is made of, for example, aluminum. The fin 30 may be a plate fin. The header 40 is made of, for example, aluminum, in which a refrigerant flows inside and the refrigerant is divided into a plurality of connected flat pipes 20. As described above, the fin 30 may be made of the same material as the flat tube 20, or may be made of a different material.

The header 40 has a header 40 that connects one end of the plurality of flat tubes 20 and a header 40 that connects the other ends of the plurality of flat tubes 20. The inside of the header 40 may be configured such that the flow path 21 through which the refrigerant flows is partitioned by one or a plurality of partitions. A refrigerant pipe 5 is connected to one of the headers 40, and the header 40 is connected to the flow path switching device 7 by the refrigerant pipe 5. A refrigerant pipe 5 is connected to the other header 40, and the header 40 is connected to the expansion portion 10 by the refrigerant pipe 5. The header 40 may be made of the same material as the flat tube 20.

FIG. 3 is a cross-sectional view showing a flat tube 20 and fins 30 according to the first embodiment, and is a diagram showing a part of the AA cross section of FIG. In FIG. 3, air flows from above to below. As shown in FIG. 3, the fins 30 are provided between the flat tubes 20 and have a plurality of louvers 32 provided on the inclined surface 30a. Here, in the fin 30, the flat surface portion without the louver 32 is wider on the upstream side of the air flow than on the downstream side. A rectangular slit 33 is formed in the middle of the plurality of louvers 32.

At the upstream end of the fin 30, two holes 34, which are rectangular openings 50 extending in the longitudinal direction of the fin 30, are formed. Specifically, the hole 34 is formed on the upstream side of 3/4 L from the downstream end portion with respect to the total length L in the longitudinal direction of the fin 30. As a result, in the fin 30, the upstream end of the air flow has a smaller heat transfer area than the downstream end. Further, the downstream end of the fin 30 is located on the same surface as the downstream end of the flat tube 20. The downstream end of the fin 30 may be located upstream of the downstream end of the flat tube 20. The upstream end of the flat tube 20 is at the same position as the upstream end of the fin 30.

According to the first embodiment, the upstream end of the air flow of the flat tube 20 is at the same position as the upstream end of the fin 30. Since the fin 30 does not protrude from the flat tube 20, it is possible to prevent the fin 30 from tipping over during manufacturing or transportation. Therefore, the strength of the fin 30 can be ensured. An opening 50 is formed at the upstream end of the fin 30. As a result, it is possible to balance the amount of heat exchange on the upstream side and the amount of heat exchange on the downstream side of the fin 30. That is, the strength of the fin 30 can be ensured while balancing the heat exchange amount on the upstream side and the heat exchange amount on the downstream side.

Further, a hole 34, which is an opening 50, is formed at the upstream end of the fin 30. In general, the air exchanged for heat on the upstream side of the fin 30 is deprived of heat or cold heat by the amount of heat exchanged, so that the amount of heat exchange on the downstream side is reduced. In the first embodiment, since the hole 34 having an opening 50 is formed at the upstream end of the fin 30, the upstream end of the air flow in the fin 30 has a heat transfer area larger than that of the downstream end. Is small. Therefore, it is possible to balance the amount of heat exchange on the upstream side and the amount of heat exchange on the downstream side of the fin 30. As described above, in the first embodiment, the strength of the fin 30 can be ensured while balancing the heat exchange amount on the upstream side and the heat exchange amount on the downstream side of the fin 30.

Conventionally, there is known a technique in which the upstream end of the fin air flow is an extension protruding from the upstream end of the flat tube. In this case, the protruding fins may collapse during manufacturing or transportation, and the heat transfer performance may deteriorate. If the fin is formed with a drainage slit, the strength of the fin is further reduced, and the possibility that the fin will fall is increased. Further, if the extension portion of the fin is to be eliminated, the heat transfer area on the upstream side of the fin becomes large, so that frost is likely to be formed on the upstream side of the fin. Therefore, the frost bearing capacity is reduced.

On the other hand, in the first embodiment, in addition to the upstream end of the flat tube 20 being at the same position as the upstream end of the fin 30, the upstream end of the fin 30 has an opening 50. A hole 34 is formed. As a result, the strength of the fin 30 can be ensured while balancing the amount of heat exchange on the upstream side and the amount of heat exchange on the downstream side of the fin 30.

Further, since the hole 34 which is the opening 50 is formed at the upstream end of the fin 30, heat transfer on the upstream side of the fin 30 can be suppressed and uneven frost can be suppressed. As a result, it is possible to prevent the ventilation passage 31 through which air flows from being blocked by frost. Further, the drainage property can be improved by allowing the condensed water adhering to the fin 30 to pass through the hole 34.

Embodiment 2.
FIG. 4 is a cross-sectional view showing a flat tube 20 and fins 130 according to the second embodiment. The heat exchanger 108 of the second embodiment is different from the first embodiment in that the opening 50 is a gap 134 formed between the fin 130 and the flat tube 20 at the upstream end portion. In the second embodiment, the parts common to the first embodiment are designated by the same reference numerals, the description thereof will be omitted, and the differences from the first embodiment will be mainly described.

As shown in FIG. 4, the upstream end of the fin 130 is narrower than the downstream end. As a result, a gap 134 is formed between the fin 130 and the flat tube 20 at the upstream end. The upstream end of the flat tube 20 is at the same position as the upstream end of the fin 130, as in the first embodiment.

According to the second embodiment, the upstream end of the flat tube 20 is at the same position as the upstream end of the fin 130. Since the fin 130 does not protrude more than the flat tube 20, it is possible to prevent the fin 130 from tipping over during manufacturing or transportation. That is, the strength of the fin 130 can be ensured. Further, since the gap 134 is formed between the fin 130 and the flat tube 20 at the upstream end, the heat transfer area of the fin 130 is smaller at the upstream end of the air flow than at the downstream end. .. Therefore, it is possible to balance the heat exchange amount on the upstream side and the heat exchange amount on the downstream side of the fin 130. As described above, in the second embodiment, the strength of the fin 130 can be ensured while balancing the heat exchange amount on the upstream side and the heat exchange amount on the downstream side of the fin 130.

Further, since the gap 134 is formed between the flat tube 20 and the upstream end of the fin 130, heat transfer on the upstream side of the fin 130 can be suppressed and uneven frost can be suppressed. As a result, it is possible to prevent the ventilation passage 31 through which air flows from being blocked by frost. Further, the drainage property can be improved by allowing the condensed water adhering to the fin 130 to pass through the gap 134.

Embodiment 3.
FIG. 5 is a cross-sectional view showing a flat tube 220 and fins 230 according to the third embodiment. The heat exchanger 208 of the third embodiment is different from the first embodiment in that the opening 50 is a gap 234 formed between the fin 230 and the flat tube 220 at the upstream end portion. In the third embodiment, the parts common to the first and second embodiments are designated by the same reference numerals, the description thereof will be omitted, and the differences from the first and second embodiments will be mainly described.

As shown in FIG. 5, the upstream end of the flat tube 220 is narrower than the downstream end. The flat tube 220 has a curved surface shape with a thin tip on the upstream side. As a result, a gap 234 is formed between the fin 230 and the flat tube 220 at the upstream end. The upstream end of the flat tube 220 protrudes from the upstream end of the fin 230.

According to the third embodiment, the upstream end of the flat tube 220 protrudes from the upstream end of the fin 230. Since the fin 230 does not protrude from the flat tube 220, it is possible to prevent the fin 230 from tipping over during manufacturing or transportation. That is, the strength of the fin 230 can be ensured. Further, since the gap 234 is formed between the fin 230 and the flat tube 220 at the upstream end, the upstream end of the air flow in the fin 230 has a smaller heat transfer area than the downstream end. .. Therefore, it is possible to balance the amount of heat exchange on the upstream side and the amount of heat exchange on the downstream side of the fin 230. As described above, in the third embodiment, the strength of the fin 230 can be ensured while balancing the heat exchange amount on the upstream side and the heat exchange amount on the downstream side of the fin 230.

Further, since a gap 234 is formed between the fin 230 and the flat tube 220 at the upstream end, heat transfer on the upstream side of the fin 230 can be suppressed and uneven frost can be suppressed. As a result, it is possible to prevent the ventilation passage 31 through which air flows from being blocked by frost. Further, the drainage property can be improved by allowing the condensed water adhering to the fin 230 to pass through the gap 234. Further, since the tip of the flat tube 220 has a curved surface shape, the ventilation resistance can be reduced.

FIG. 6 is a cross-sectional view showing a flat tube 220 and fins 230 according to the third embodiment. In the third embodiment, a case where two rows of flat tubes 220 are arranged in a row direction parallel to the direction in which air flows is illustrated. In this case, as shown in FIG. 6, the tip of the flat tube 220 on the upstream side is tapered, and the tip of the flat tube 220 on the downstream side is not tapered. This is because heat transfer to the fins 230 has already been sufficiently performed at the downstream end of the flat tube 220 on the upstream side, so that it is not necessary to thin the tip of the flat tube 220 on the downstream side.

(Modification example)
FIG. 7 is a cross-sectional view showing a flat tube 220a and fins 230a according to a modified example of the third embodiment. As shown in FIG. 7, the heat exchanger 208a of the modified example has a gap 234a in which a portion adjacent to the fin 230a is cut off on one side of the upstream end portion of the flat tube 220a. Also in the modified example, since the gap 234a is formed between the fin 230a and the flat tube 220a at the upstream end, the upstream end of the air flow in the fin 230a transfers heat more than the downstream end. The area is small. Therefore, in the modified example, the heat exchange amount on the upstream side and the heat exchange amount on the downstream side of the fin 230a can be balanced.

Embodiment 4.
FIG. 8 is a cross-sectional view showing a flat tube 20 and fins 330 according to the fourth embodiment. The heat exchanger 308 of the fourth embodiment is different from the first to third embodiments in that it includes a reinforcing portion 360 for reinforcing the fins 330. In the fourth embodiment, the parts common to the first to third embodiments are designated by the same reference numerals, the description thereof will be omitted, and the differences from the first to third embodiments will be mainly described.

As shown in FIG. 8, the upstream end of the fin 330 protrudes from the upstream end of the flat tube 20. The reinforcing portion 360 is provided between the portions of the fins 330 that protrude from the flat tube 20. The reinforcing portion 360 is made of, for example, a resin having a large thermal resistance.

According to the fourth embodiment, although the fin 330 protrudes from the flat tube 20, the reinforcing portion 360 is provided between the portions of the fin 330 protruding from the flat tube 20, so that the reinforcing portion 360 is provided at the time of manufacture. Alternatively, it is possible to prevent the fin 330 from falling during transportation. That is, the strength of the fin 330 can be ensured. Further, since the upstream end of the fin 330 is not in contact with the flat tube 20, the upstream end of the air flow in the fin 330 has a smaller heat transfer area than the downstream end. Therefore, it is possible to balance the heat exchange amount on the upstream side and the heat exchange amount on the downstream side of the fin 330. As described above, in the fourth embodiment, the strength of the fin 330 can be ensured while balancing the heat exchange amount on the upstream side and the heat exchange amount on the downstream side of the fin 330.

Further, since the upstream end of the fin 330 is not in contact with the flat tube 20, heat transfer on the upstream side of the fin 330 can be suppressed and uneven frost can be suppressed. As a result, it is possible to prevent the ventilation passage 31 through which air flows from being blocked by frost. Further, the condensed water adhering to the fin 330 is transmitted through the reinforcing portion 360 which is a resin, so that the drainage property can be improved.

Embodiment 5.
9 is a front view showing the heat exchanger 408 according to the fifth embodiment, and FIG. 10 is a cross-sectional view showing the flat tube 20 and the fins 430 according to the fifth embodiment. The fifth embodiment is different from the first to fourth embodiments in that the reinforcing portion 434 is formed on the fin 430. In the fifth embodiment, the parts common to the first to fourth embodiments are designated by the same reference numerals, and the description thereof will be omitted, and the differences from the first to fourth embodiments will be mainly described.

As shown in FIGS. 9 and 10, a plurality of reinforcing portions 434 for reinforcing the fin 430 are formed at the upstream end portion of the inclined surface 30a of the fin 430. The reinforcing portion 434 is obtained by bending the fin 430 into a rectangular shape and an uneven shape. Further, the upstream end of the fin 430 protrudes from the upstream end of the flat tube 20.

According to the fifth embodiment, although the fin 430 protrudes from the flat tube 20, the fin 430 collapses during manufacturing or transportation because the reinforcing portion 434 is formed at the upstream end of the fin 430. Can be suppressed. That is, the strength of the fin 430 can be ensured. Further, since the upstream end of the fin 430 is not in contact with the flat tube 20, the upstream end of the air flow in the fin 430 has a smaller heat transfer area than the downstream end. Therefore, it is possible to balance the amount of heat exchange on the upstream side and the amount of heat exchange on the downstream side of the fin 430. As described above, in the fifth embodiment, the strength of the fin 430 can be ensured while balancing the heat exchange amount on the upstream side and the heat exchange amount on the downstream side of the fin 430.

Further, since the upstream end of the fin 430 is not in contact with the flat tube 20, heat transfer on the upstream side of the fin 430 can be suppressed and uneven frost can be suppressed. As a result, it is possible to prevent the ventilation passage 31 through which air flows from being blocked by frost. Further, the condensed water adhering to the fin 430 travels through the reinforcing portion 434 which is a resin, so that the drainage property can be improved.

(Modification example)
FIG. 11 is a cross-sectional view showing a flat tube 20 and fins 430a according to a modified example of the fifth embodiment. As shown in FIG. 11, in the heat exchanger 408a of the modified example, the fin 430a protrudes from the flat tube 20 more than in the fifth embodiment. The reinforcing portion 434a is larger than that of the fifth embodiment. As a result, although the fin 430a protrudes larger than the flat tube 20, the reinforcing portion 434a is formed large at the upstream end of the fin 430a, so that the fin 430a can be prevented from falling during manufacturing or transportation. Can be done. Further, since the wide region of the upstream end of the fin 430a is not in contact with the flat tube 20, the upstream end of the air flow in the fin 430a has a smaller heat transfer area than the downstream end. Therefore, it is possible to balance the amount of heat exchange on the upstream side and the amount of heat exchange on the downstream side of the fin 430a. As described above, in the modified example, the strength of the fin 430a can be secured while balancing the heat exchange amount on the upstream side and the heat exchange amount on the downstream side of the fin 430a.

Embodiment 6.
FIG. 12 is a cross-sectional view showing a flat tube 20 and fins 530 according to the sixth embodiment. The heat exchanger 508 of the sixth embodiment is different from the first to fifth embodiments in that the opening / closing louver 535 is provided in the opening 50. In the sixth embodiment, the parts common to the first to fifth embodiments are designated by the same reference numerals, the description thereof will be omitted, and the differences from the first to fifth embodiments will be mainly described.

As shown in FIG. 12, the fin 530 has an opening / closing louver 535 provided in the opening 50 to open / close the opening 50. The upstream end of the flat tube 20 is at the same position as the upstream end of the fin 530, as in the first embodiment.

According to the sixth embodiment, the upstream end of the flat tube 20 is at the same position as the upstream end of the fin 530. Since the fin 530 does not protrude from the flat tube 20, it is possible to prevent the fin 530 from collapsing during manufacturing or transportation. That is, the strength of the fin 530 can be ensured. Further, since an opening 50 for opening and closing the opening / closing louver 535 is formed at the upstream end of the fin 530, the upstream end of the air flow in the fin 530 has a smaller heat transfer area than the downstream end. .. Therefore, it is possible to balance the amount of heat exchange on the upstream side and the amount of heat exchange on the downstream side of the fin 530. As described above, in the sixth embodiment, the strength of the fin 530 can be ensured while balancing the heat exchange amount on the upstream side and the heat exchange amount on the downstream side of the fin 530.

Further, since the opening 50 for opening and closing the opening / closing louver 535 is formed at the upstream end of the fin 530, heat transfer on the upstream side of the fin 530 can be suppressed and uneven frost can be suppressed. As a result, it is possible to prevent the ventilation passage 31 through which air flows from being blocked by frost. Further, the drainage property can be improved by allowing the condensed water adhering to the fin 530 to pass through the opening 50.

1 air conditioner, 2 outdoor unit, 3 indoor unit, 4 refrigerant circuit, 5 refrigerant pipe, 6 compressor, 7 flow path switching device, 8 heat exchanger, 9 outdoor blower, 10 expansion part, 11 indoor heat exchanger, 12 indoor blower, 20 flat tube, 21 flow path, 30 fins, 30a inclined surface, 31 ventilation passage, 32 louver, 33 slit, 34 hole, 40 header, 50 opening, 108 heat exchanger, 130 fin, 134 gap, 208 , 208a heat exchanger, 220, 220a flat tube, 230 fins, 234,234a gap, 308 heat exchanger, 330 fins, 360 reinforcements, 408,408a heat exchangers, 430, 430a fins, 434,434a reinforcements, 508 heat exchanger, 530 fins, 535 open / close louver.

Claims

Multiple flat pipes through which the refrigerant flows inside,
A plurality of fins provided between the flat tubes and transmitting the heat of the refrigerant flowing through the flat tubes are provided.
The upstream end of the air flow in the flat tube is at the same position as the upstream end of the fin or protrudes from the upstream end of the fin.
A heat exchanger having an opening formed in the upstream end of the flat tube or the upstream end of the fin.
The opening is
The heat exchanger according to claim 1, which is a hole formed in the upstream end of the fin.
The opening is
The heat exchanger according to claim 1 or 2, which is a gap formed between the fin and the flat tube at the upstream end.
The heat exchanger according to claim 3, wherein the upstream end of the fin is narrower than the downstream end.
The heat exchanger according to claim 3 or 4, wherein the upstream end of the flat tube is narrower than the downstream end.
The fins
The heat exchanger according to any one of claims 1 to 5, which is provided in the opening and has an opening / closing louver for opening / closing the opening.
Multiple flat pipes through which the refrigerant flows inside,
A plurality of fins provided between the flat pipes to transfer the heat of the refrigerant flowing through the flat pipes, and the upstream end of the air flow protruding from the upstream end of the flat pipes.
A reinforcing portion provided between the portions of the fins protruding from the flat tube to reinforce the fins, and
A heat exchanger equipped with.
Multiple flat pipes through which the refrigerant flows inside,
A plurality of fins provided between the flat pipes to transfer the heat of the refrigerant flowing through the flat pipes, and the upstream end of the air flow protruding from the upstream end of the flat pipes. Equipped with
A heat exchanger in which an uneven reinforcing portion for reinforcing the fin is formed at the upstream end portion of the fin.
An air conditioner comprising the heat exchanger according to any one of claims 1 to 8.