JP6701371B2 - Heat exchanger and refrigeration cycle device - Google Patents

Description

  The present invention relates to a fin-and-tube heat exchanger, and a refrigeration cycle apparatus including the fin-and-tube heat exchanger.

  Conventionally, a fin-and-tube heat exchanger including a plurality of plate-shaped fins arranged in parallel with a predetermined fin pitch interval and a plurality of heat transfer tubes penetrating the fins in the fin arrangement direction. It has been known.

  A plurality of openings such as through holes or notches are formed in the plurality of fins, and heat transfer tubes are inserted into these openings. As a result, the plurality of heat transfer tubes are in a state of penetrating the fins along the direction in which the fins are arranged. The end of each heat transfer tube is connected to a distribution pipe or a header that forms a refrigerant flow path together with the heat transfer tube. Then, in the heat exchanger, heat is exchanged between the heat exchange fluid such as air flowing between the fins and the heat exchanged fluid such as water or refrigerant flowing in the heat transfer tube.

  Further, conventionally, there is known a heat exchanger in which a cut-and-raised piece called a slit or a louver which is opened in a direction in which air mainly flows is formed. Further, conventionally, there is known a heat exchanger in which a protruding portion called a scratch or a waffle which is protruding in a direction in which air mainly flows is formed. In such a heat exchanger, the cut-and-raised pieces or the protrusions increase the surface area for heat exchange and improve the heat exchange performance.

  Furthermore, conventionally, a heat exchanger in which a plurality of flow paths are formed inside the heat transfer tube, a heat exchanger in which a groove is formed on the inner surface of the heat transfer tube, and the like are known. Also in such a heat exchanger, the surface area for heat exchange is increased and the heat exchange performance is improved by the plurality of channels or grooves.

  Some heat transfer tubes used in such a heat exchanger have a flat cross section such as an elliptical shape or an oval shape. By the way, for example, when the heat exchanger operates as an evaporator in an environment where the outside air temperature is below freezing, frost is formed on the windward side in the ventilation direction where the absolute humidity of the air is large and the runway section becomes thin and the temperature boundary layer becomes thin. It will be easier. In particular, on the outer surface of the heat exchanger, the temperature of the portion around the heat transfer tube that is closest to the refrigerant flowing in the flat heat transfer tube decreases, and the temperature difference with the air increases, so many parts adhere to this area. To frost. Therefore, there is proposed a structure in which a sufficient fin region is provided on the windward side to prevent the gap between the heat transfer tubes from being closed even when frost is formed (for example, Patent Document 1).

  On the other hand, the frost is melted by the defrosting operation to become water drops. When the defrosting operation is finished, the frosting operation is started again, and air starts to flow through the heat exchanger. Therefore, there is a problem that the water droplets generated in the defrosting operation move rearward, stay in the upper portion or the lower portion of the flat heat transfer tube, and are not appropriately discharged. Therefore, it is proposed that a fin region is provided on the leeward side in the ventilation direction to suppress the retention of water droplets after the start of ventilation (for example, Patent Document 2).

Japanese Patent No. 3264525 Japanese Patent No. 5736794

  However, as described above, the heat exchanger described in Patent Document 1 has a problem that when the frosting operation is started, the heat exchanger stays in the upper and lower portions of the flat heat transfer tube and is not appropriately discharged, and thus the heat exchanger The drainage of the container is not sufficient. Further, the heat exchanger described in Patent Document 2 has a problem in that the heat transfer tube on the windward side is exposed and frost spreads from this portion as a starting point, so that the air passage is easily blocked.

  Here, if the water droplets remain in the heat transfer tube region when the defrosting operation is finished and the heating operation is started, the water droplets will freeze and grow again. Therefore, after the defrosting operation is completed, the water droplets remaining in the heat transfer tube region at the start of the heating operation lead to a decrease in reliability due to damage to the heat transfer tube or the like. In addition, since the periphery of the heat transfer tube is closed by frost due to re-freezing, it affects an increase in ventilation resistance and causes a decrease in frost resistance, which is a performance maintaining power against frost formation. In the next defrosting operation, it is necessary to melt not only the frost adhering to the heat exchanger during the heating operation but also frozen water droplets. For this reason, the comfort is reduced due to the increase in the defrosting time, and the average heating capacity is reduced during a certain period of time by repeating the heating operation and the defrosting operation. Further, when the air passage is closed due to frost, the amount of air flow is reduced, resulting in a reduction in capacity during heating operation.

  That is, the heat exchanger having the flat heat transfer tube described in Patent Document 1 or 2 cannot satisfy both the drainage performance and the frost resistance, and thus has the above-mentioned problems.

  The present invention has been made in order to solve the above problems, is a heat exchanger having a flat heat transfer tube, improved drainage performance and frost resistance both compatible with conventional heat exchangers. It is an object of the present invention to provide a heat exchanger and a refrigeration cycle device equipped with this heat exchanger.

A heat exchanger according to the present invention is a heat exchanger to which air is supplied from a fan, and includes a plate-shaped fin, a first heat transfer tube having a flat cross section inserted into the fin, and the fin. A second heat transfer tube that is inserted and is arranged side by side in the direction of gravity at a distance from the first heat transfer tube and has a flat cross-section; and a wind in the air ventilation direction of the first heat transfer tube. A line connecting the first wind upper end that is the upper end and the second wind upper end that is the windward end in the ventilation direction of the second heat transfer tube is a first virtual line, A first wind lower end that is an end on the leeward side in the ventilation direction of the first heat transfer tube, and a second wind lower end that is an end on the leeward side in the ventilation direction of the second heat transfer tube. When a line connecting the and the second virtual line is defined as a second virtual line, the fin includes a windward fin region defined by an end portion of the fin on the windward side in the ventilation direction and the first virtual line, and A heat transfer tube region defined by one imaginary line and the second imaginary line, and a leeward fin region defined by the second imaginary line and an end of the fin on the leeward side in the ventilation direction. The heat exchanger has two rows: a windward heat exchanger arranged on the windward side in the ventilation direction and a leeward heat exchanger arranged on the leeward side in the ventilation direction. A structure heat exchanger, wherein in the windward heat exchanger, the length of the upwind fin region along the ventilation direction is longer than the length of the downwind fin region along the ventilation direction, and the downwind side. The length along the ventilation direction of the upwind fin region in the heat exchanger and the length along the ventilation direction of the downwind fin region in the upwind heat exchanger are equal, and the length in the downwind heat exchanger is the same. The length of the downwind fin region along the ventilation direction and the length of the upwind fin region of the upwind heat exchanger along the ventilation direction are equal .

  When the heat exchanger is installed as the outdoor heat exchanger of the refrigeration cycle and the heating operation is performed, the moisture in the outside air sent from the blower fan frosts on the heat exchanger, and then the defrosting operation causes the frost to disappear. To thaw. According to the present invention, in the fin of the heat exchanger, the length of the upwind fin region along the ventilation direction of the air supplied from the fan is longer than the length of the downwind fin region. That is, the area on the windward side where the air from the blower fan first hits is relatively long. Therefore, it is possible to prevent the gap between the heat transfer tubes from being closed on the windward side of the fins that are relatively frosted during the heating operation. Then, the frost melted during the defrosting operation, that is, the water droplets, is promptly discharged downward from the windward fin region. Further, according to the present invention, since the fin is provided with the leeward fin region, when air is supplied from the fan, the water droplets melted during the defrosting operation flow above and below the heat transfer tube, and quickly from the leeward fin region. It is discharged downward.

  As described above, according to the present invention, both the frost resistance and the drainage performance can be improved in the heat exchanger and the refrigeration cycle apparatus including the heat exchanger.

It is a refrigerant circuit diagram showing an example of the refrigerating cycle device concerning Embodiment 1 of the present invention. It is a perspective view showing an example of the outdoor heat exchanger in the refrigerating cycle device concerning Embodiment 1 of the present invention. It is a principal part enlarged view in the outdoor heat exchanger shown in FIG. It is a principal part enlarged view in the outdoor heat exchanger shown in FIG. It is a perspective view which shows the process of inserting a heat transfer tube and a fin. 5 is an enlarged view of a main part of the outdoor heat exchanger according to Comparative Example 1. FIG. 7 is an enlarged view of a main part of an outdoor heat exchanger according to Comparative Example 2. FIG. 7 is an enlarged view of a main part of an outdoor heat exchanger according to Comparative Example 3. FIG. It is a principal part enlarged view in the outdoor heat exchanger which concerns on Embodiment 2 of this invention. It is a principal part enlarged view in the outdoor heat exchanger which concerns on Embodiment 3 of this invention. It is a principal part enlarged view in the outdoor heat exchanger which concerns on Embodiment 4 of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings as appropriate. In the following drawings including FIG. 1, the relationship of the sizes of the respective constituent members may be different from the actual one. In addition, in the following drawings including FIG. 1, the same reference numerals are the same or equivalent, and this is common to the entire text of the specification. Furthermore, the forms of the constituent elements shown in the entire text of the specification are merely examples, and the present invention is not limited to these descriptions.

Embodiment 1.
First, the refrigeration cycle apparatus 501 according to Embodiment 1 of the present invention will be described. FIG. 1 is a refrigerant circuit diagram showing an example of a refrigeration cycle device according to Embodiment 1 of the present invention. In addition, in FIG. 1, the flow of the refrigerant during the cooling operation is indicated by a dashed arrow, and the flow of the refrigerant during the heating operation is indicated by a solid arrow. The refrigeration cycle device 501 is an example of the refrigeration cycle device according to the present invention.

[Configuration of Refrigeration Cycle Device 501]
As shown in FIG. 1, the refrigeration cycle apparatus 501 includes a compressor 502, an indoor heat exchanger 503, an indoor fan 504, a throttle device 505, an outdoor heat exchanger 10, an outdoor fan 506, and a four-way valve 507. .. The compressor 502, the indoor heat exchanger 503, the expansion device 505, the outdoor heat exchanger 10 and the four-way valve 507 are connected by a refrigerant pipe to form a refrigerant circuit.

  The compressor 502 compresses the refrigerant. The refrigerant compressed by the compressor 502 is discharged and sent to the four-way valve 507. The compressor 502 can be configured by, for example, a rotary compressor, a scroll compressor, a screw compressor, a reciprocating compressor, or the like.

  The indoor heat exchanger 503 functions as a condenser during heating operation and functions as an evaporator during cooling operation. The indoor heat exchanger 503 is, for example, a fin-and-tube heat exchanger, a microchannel heat exchanger, a shell-and-tube heat exchanger, a heat pipe heat exchanger, a double-tube heat exchanger, or a plate heat exchanger. It can be configured with a container or the like.

  The expansion device 505 expands and decompresses the refrigerant that has passed through the indoor heat exchanger 503 or the outdoor heat exchanger 10. The expansion device 505 may be composed of, for example, an electric expansion valve capable of adjusting the flow rate of the refrigerant. As the expansion device 505, not only an electric expansion valve, but also a mechanical expansion valve having a diaphragm as a pressure receiving portion, a capillary tube, or the like can be applied.

  The outdoor heat exchanger 10 functions as an evaporator during heating operation and as a condenser during cooling operation. The outdoor heat exchanger 10 also has a configuration in which the heat exchanger is bent in the extension direction of the heat transfer tube in order to improve the mounting efficiency when the outdoor heat exchanger 10 is mounted in the outdoor unit. The outdoor heat exchanger 10 will be described in detail later.

  The four-way valve 507 switches the flow of the refrigerant between heating operation and cooling operation. That is, the four-way valve 507 is switched to connect the discharge port of the compressor 502 and the indoor heat exchanger 503 and connect the suction port of the compressor 502 and the outdoor heat exchanger 10 during the heating operation. Further, the four-way valve 507 is switched to connect the discharge port of the compressor 502 and the outdoor heat exchanger 10 and connect the suction port of the compressor 502 and the indoor heat exchanger 503 during the cooling operation.

  The indoor fan 504 is attached to the indoor heat exchanger 503, and supplies air that is a heat exchange fluid to the indoor heat exchanger 503. The outdoor fan 506 is attached to the outdoor heat exchanger 10 and supplies air as a heat exchange fluid to the outdoor heat exchanger 10.

[Operation of Refrigeration Cycle Device 501]
Next, the operation of the refrigeration cycle apparatus 501 will be described along with the flow of the refrigerant. First, the cooling operation performed by the refrigeration cycle device 501 will be described. The flow of the refrigerant during the cooling operation is indicated by the broken line arrow in FIG. Here, the operation of the refrigeration cycle apparatus 501 will be described, taking as an example the case where the heat exchange fluid is air and the heat exchanged fluid is a refrigerant.

  As shown in FIG. 1, by driving the compressor 502, a high temperature and high pressure refrigerant in a gas state is discharged from the compressor 502. Hereinafter, the refrigerant flows according to the broken line arrow. The single-phase high-temperature high-pressure gas refrigerant discharged from the compressor 502 flows into the outdoor heat exchanger 10 functioning as a condenser via the four-way valve 507. In the outdoor heat exchanger 10, heat is exchanged between the flowing high-temperature and high-pressure gas refrigerant and the air supplied by the outdoor fan 506, and the high-temperature and high-pressure gas refrigerant is condensed to form a single-phase high-pressure gas refrigerant. It becomes a liquid refrigerant.

  The high-pressure liquid refrigerant sent from the outdoor heat exchanger 10 becomes a two-phase refrigerant of a low-pressure gas refrigerant and a liquid refrigerant by the expansion device 505. The two-phase state refrigerant flows into the indoor heat exchanger 503 that functions as an evaporator. In the indoor heat exchanger 503, heat is exchanged between the two-phase state refrigerant that has flowed in and the air supplied by the indoor fan 504, so that the liquid refrigerant of the two-phase state refrigerant evaporates into a single-phase state. It becomes a low-pressure gas refrigerant. Due to this heat exchange, the inside of the room is cooled. The low-pressure gas refrigerant sent from the indoor heat exchanger 503 flows into the compressor 502 via the four-way valve 507, is compressed into a high-temperature and high-pressure gas refrigerant, and is discharged from the compressor 502 again. Hereinafter, this cycle is repeated.

  Next, the heating operation performed by the refrigeration cycle apparatus 501 will be described. The flow of the refrigerant during the heating operation is shown by the solid arrow in FIG.

  As shown in FIG. 1, by driving the compressor 502, the high-temperature and high-pressure gas-state refrigerant is discharged from the compressor 502. Hereinafter, the refrigerant flows according to the solid arrow. The single-phase high-temperature high-pressure gas refrigerant discharged from the compressor 502 flows into the indoor heat exchanger 503 functioning as a condenser via the four-way valve 507. In the indoor heat exchanger 503, heat is exchanged between the flowing high-temperature and high-pressure gas refrigerant and the air supplied by the indoor fan 504, and the high-temperature and high-pressure gas refrigerant is condensed to form a single-phase high-pressure gas refrigerant. It becomes a liquid refrigerant. This heat exchange heats the room.

  The high-pressure liquid refrigerant sent from the indoor heat exchanger 503 becomes a two-phase refrigerant of a low-pressure gas refrigerant and a liquid refrigerant by the expansion device 505. The two-phase refrigerant flows into the outdoor heat exchanger 10 that functions as an evaporator. In the outdoor heat exchanger 10, heat exchange is performed between the two-phase refrigerant that has flowed in and the air supplied by the outdoor fan 506, and the liquid refrigerant of the two-phase refrigerant evaporates and becomes a single-phase refrigerant. It becomes a low-pressure gas refrigerant.

  The low-pressure gas refrigerant sent from the outdoor heat exchanger 10 flows into the compressor 502 via the four-way valve 507, is compressed into high-temperature and high-pressure gas refrigerant, and is discharged from the compressor 502 again. Hereinafter, this cycle is repeated.

  When the refrigerant flows into the compressor 502 in a liquid state during the above cooling operation and heating operation, liquid compression occurs, which causes a failure of the compressor 502. Therefore, it is desirable that the refrigerant flowing out from the evaporator is a single-phase gas refrigerant. During the cooling operation, the indoor heat exchanger 503 functions as an evaporator, and during the heating operation, the outdoor heat exchanger 10 functions as an evaporator.

  Here, in the evaporator, when heat exchange is performed between the air supplied from the fan and the refrigerant flowing inside the heat transfer tube forming the evaporator, moisture in the air is condensed, Water droplets form on the surface of the evaporator. The water droplets generated on the surface of the evaporator travel down the surfaces of the fins and the heat transfer tubes and fall downward, and are discharged below the evaporator as drain water.

  Further, the outdoor heat exchanger 10 functions as an evaporator during the heating operation in the low outside air temperature state. Therefore, during the heating operation, moisture in the air may frost the outdoor heat exchanger 10. Therefore, in a refrigeration cycle device or the like capable of heating operation, normally, a defrosting operation for removing frost is performed when the outside air has a certain temperature (for example, 0° C.) or less.

  The defrosting operation is an operation of supplying hot gas, which is a high-temperature and high-pressure gas refrigerant, from the compressor 502 to the outdoor heat exchanger 10 in order to prevent frost from adhering to the outdoor heat exchanger 10 that functions as an evaporator. That is. The defrosting operation may be executed when the duration of the heating operation reaches a predetermined value (for example, 30 minutes). In addition, the defrosting operation may be performed before the heating operation when the outdoor heat exchanger 10 has a constant temperature (for example, minus 6°C) or less. The frost and ice attached to the outdoor heat exchanger 10 are melted by the hot gas supplied to the outdoor heat exchanger 10 during the defrosting operation.

  For example, a bypass refrigerant pipe (not shown) is provided between the outlet of the compressor 502 and the outdoor heat exchanger 10 so that hot gas can be directly supplied from the compressor 502 to the outdoor heat exchanger 10 during the defrosting operation. It can be configured to connect. In addition, the discharge port of the compressor 502 is connected to the outdoor heat exchanger 10 via a refrigerant flow path switching device such as a four-way valve 507 so that hot gas can be supplied from the compressor 502 to the outdoor heat exchanger 10. It may be configured to.

[Details of outdoor heat exchanger 10]
FIG. 2 is a perspective view showing an example of the outdoor heat exchanger in the refrigeration cycle device according to Embodiment 1 of the present invention. 3 and 4 are enlarged views of a main part of the outdoor heat exchanger shown in FIG. FIG. 5 is a perspective view showing a step of inserting the heat transfer tubes and the fins. Note that in FIG. 2 and subsequent figures, the X direction is the lateral direction, and represents the lateral direction of the fins 30 of the outdoor heat exchanger 10, that is, the width direction. The Y direction is the lateral direction, and represents the direction in which the fins 30 forming the same heat exchange section are arranged in parallel. The Z direction is the vertical direction, that is, the direction of gravity, and represents the longitudinal direction of the fins 30. The white arrow indicates the flow direction of the air supplied from the outdoor fan 506 to the outdoor heat exchanger 10. As can be seen from FIG. 2, the outdoor heat exchanger 10 according to the first embodiment is supplied with air in the X direction from the outdoor fan 506 shown in FIG. Further, FIG. 3 shows a main part when the outdoor heat exchanger 10 is observed in the Y direction. Further, FIG. 4 shows a main part when the outdoor heat exchanger 10 is observed in the X direction.

  The outdoor heat exchanger 10 is, for example, a two-row structure heat exchanger, and includes a windward side heat exchanger 601 and a leeward side heat exchanger 602. The windward-side heat exchanger 601 and the leeward-side heat exchanger 602 are fin-and-tube heat exchangers, and flow in the direction of the air supplied from the outdoor fan 506 shown in FIG. 1, that is, in the X direction, which is the ventilation direction. It is lined up alongside. The windward side heat exchanger 601 is arranged on the windward side in the ventilation direction of the air supplied from the outdoor fan 506, and the leeward heat exchanger 602 is arranged on the leeward side in the ventilation direction of the air supplied from the outdoor fan 506. Has been done. One end of the heat transfer pipe of the windward heat exchanger 601 is connected to the windward header collecting pipe 603. One end of the heat transfer pipe of the leeward heat exchanger 602 is connected to the leeward header collecting pipe 604. The other end of the heat transfer tube of the windward heat exchanger 601 and the other end of the heat transfer tube of the leeward heat exchanger 602 are connected to the inter-row connection member 605.

  That is, in the outdoor heat exchanger 10 according to the first embodiment, one of the windward heat exchanger 601 and the leeward heat exchanger 602 is transferred from one of the windward header collecting pipe 603 and the leeward header collecting pipe 604. The refrigerant is distributed to the heat tubes. Then, the refrigerant distributed to one of the heat transfer tubes of the windward side heat exchanger 601 and the leeward side heat exchanger 602 passes through the inter-row connection member 605 and then flows into the windward side heat exchanger 601 and the leeward side heat exchanger 602. It flows into the other heat transfer tube. After that, the refrigerant flowing into the other heat transfer pipe of the windward heat exchanger 601 and the leeward heat exchanger 602 merges with the other of the windward header collecting pipe 603 and the leeward header collecting pipe 604, and is sucked into the compressor 502. It flows toward the mouth or the diaphragm device 505.

  In addition, in this Embodiment 1, the windward side heat exchanger 601 and the leeward side heat exchanger 602 have the same structure. Therefore, the windward heat exchanger 601 will be described below as a representative of both. Here, the windward heat exchanger 601 and the leeward heat exchanger 602 correspond to the heat exchanger of the present invention. When one of the windward side heat exchanger 601 or the leeward side heat exchanger 602 can cover the heat exchange load of the outdoor heat exchanger 10, only one of the windward side heat exchanger 601 or the leeward side heat exchanger 602 can provide the outdoor heat. Of course, the exchanger 10 may be configured.

  As shown in FIGS. 3, 4, and 5, the outdoor heat exchanger 10 includes a plurality of fins 30 and a plurality of heat transfer tubes. Specifically, the fin 30 is a plate-shaped member that is long in the vertical direction, and is formed in, for example, a rectangular shape that is long in the vertical direction. As shown in FIG. 4, in the same heat exchange part, these fins 30 are arranged in parallel with a prescribed fin pitch interval FP.

  Regarding the plurality of heat transfer tubes, two heat transfer tubes are described as representatives in FIGS. 3 to 5. Here, the one located above in the Z direction is defined as the first heat transfer tube 21, and the one located below in the Z direction is defined as the second heat transfer tube 22. As shown in FIG. 3 and FIG. 4, the first heat transfer tube 21 and the second heat transfer tube 22 are arranged side by side in the vertical direction at regular intervals. Further, as shown in FIG. 5, the first heat transfer tube 21 and the second heat transfer tube 22 are respectively inserted in the Y direction, which is the direction in which the plurality of fins 30 are arranged side by side, and the first heat transfer tube 21 and the second heat transfer tube 22 are inserted. The heat pipe 21 and the second heat transfer pipe 22 penetrate the fins 30. The first heat transfer tube 21 and the second heat transfer tube 22 are flat tubes having a flat cross section cut along a plane orthogonal to the longitudinal direction.

  Further, in the first embodiment, the fins 30 of the outdoor heat exchanger 10 include a windward fin end portion 131 and a leeward fin end portion 132 as end portions in the X direction which is the lateral direction of the fin 30. Have Further, with respect to the heat transfer tube passing through the fin 30, the first heat transfer tube 21 has a windward side end 141 and a leeward side end 142 as an end portion in the X direction which is the lateral direction of the fin 30. The second heat transfer tube 22 has a windward side end 241 and a leeward side end 242. The windward end 141 of the first heat transfer tube 21 and the windward end 241 of the second heat transfer tube 22 are windward ends of the air supplied from the outdoor fan 506 in the ventilation direction. The leeward side end portion 142 of the first heat transfer tube 21 and the leeward side end portion 242 of the second heat transfer tube 22 are end portions on the leeward side in the ventilation direction of the air supplied from the outdoor fan 506.

  In addition, in order to explain the frosting action and the drainage action of the outdoor heat exchanger 10 according to the first embodiment, the following definitions are made.

  A first imaginary line 151 that connects the windward ends, which are the windward ends of the air supplied from the outdoor fan 506 of each heat transfer tube, with a straight line, and is supplied from the outdoor fan 506 of each heat transfer tube. A second imaginary line 152 that connects the leeward side ends, which are the leeward side ends in the air flow direction, with a straight line is defined, and each is shown by a chain line. In FIG. 3, the windward end 141 of the first heat transfer tube 21 and the windward end 241 of the second heat transfer tube 22 are connected by a first imaginary line 151, and the leeward side of the first heat transfer tube 21. The end 142 and the leeward end 242 of the second heat transfer tube 22 are connected by a second imaginary line 152. Further, a region defined by the windward fin end 131 and the first imaginary line 151 is a leeward fin region 161, and a region defined by the leeward fin end 132 and the second imaginary line 152 is a leeward fin region 162. A region defined by the first imaginary line 151 and the second imaginary line 152 is defined as a heat transfer tube region 163. The heat transfer tube area 163 is an area in which the heat transfer tube exists in a part of the Z direction. In FIG. 3, the first heat transfer tube 21 and the second heat transfer tube 22 are present in the heat transfer tube region 163. If the length of the upwind fin region 161 in the X direction, that is, the length in the ventilation direction is A, and the length of the leeward fin region 162 in the X direction, that is, the length in the ventilation direction is B, the length becomes B. In comparison, the length A is longer.

[Frosting action and drainage action of the outdoor heat exchanger 10]
Subsequently, the frosting action and the drainage action of the outdoor heat exchanger 10 according to the first embodiment will be described. In order to facilitate understanding of the effect of the outdoor heat exchanger 10 according to the first embodiment, the configurations of the outdoor heat exchangers of Comparative Example 1, Comparative Example 2, and Comparative Example 3 will be first described below. .. After that, the frosting action and the drainage action of the outdoor heat exchanger 10 according to the first embodiment will be described.

  In addition, when showing Comparative Examples 1 to 3, the reference numerals of the configurations of the first embodiment corresponding to the configurations are added with “1000”, “2000”, and “3000”, respectively. Shall be attached. For example, the outdoor heat exchanger of Comparative Example 1 is an outdoor heat exchanger 1010, the outdoor heat exchanger of Comparative Example 2 is an outdoor heat exchanger 2010, and the outdoor heat exchanger of Comparative Example 3 is an outdoor heat exchanger 3010. Shown respectively.

[Comparative Example 1]
FIG. 6 is an enlarged view of a main part of the outdoor heat exchanger according to Comparative Example 1. FIG. 6 shows a main part when the outdoor heat exchanger 1010 of Comparative Example 1 is observed in the Y direction. The outdoor heat exchanger 1010 is different from the outdoor heat exchanger 10 according to the first embodiment in that it does not have the leeward fin region 162 shown in FIG. 3. Therefore, in the outdoor heat exchanger 1010 of Comparative Example 1, the leeward end 1142 of the first heat transfer tube 1021, the leeward end 1242 of the second heat transfer tube 1022, and the leeward fin end 1132 are They are located at the same position in the X direction. The length A1 of the upwind fin region 1161 in the X direction is longer than the length A of the upwind fin region 161 in the X direction in the first embodiment shown in FIG.

  In the outdoor heat exchanger 1010 of Comparative Example 1, the frost resistance is excellent because the length of the windward fin region 1161 in the X direction is long. However, the outdoor heat exchanger 1010 does not have the leeward fin area. Therefore, after the frost is melted in the defrosting operation, when the fan operates again to start the frosting operation, the upper and lower portions of the first heat transfer tube 1021 and the second heat transfer tube 2022 are near the leeward fin end portion 1132. The water droplets that have melted in the pool accumulate and are not discharged properly. That is, the outdoor heat exchanger 1010 of Comparative Example 1 does not have sufficient drainage. As a result, the accumulated water droplets freeze again and become a resistance to the ventilation passage, reducing frost resistance, and increasing the amount of heat required for defrosting also affects the increase in defrosting time. Will end up.

[Comparative example 2]
FIG. 7 is an enlarged view of a main part of the outdoor heat exchanger according to Comparative Example 2. FIG. 7 shows a main part when the outdoor heat exchanger 2010 of Comparative Example 2 is observed in the Y direction. The outdoor heat exchanger 2010 is different from the outdoor heat exchanger 10 according to the first embodiment in that it does not have the upwind fin region 161 shown in FIG. 3. Therefore, in the outdoor heat exchanger 2010 of Comparative Example 2, the windward end 2141 of the first heat transfer tube 2021, the windward end 2241 of the second heat transfer tube 2022, and the windward fin end 2131 are They are located at the same position in the X direction. Further, the length B2 of the leeward fin region 2162 in the X direction is longer than the length B of the leeward fin region 162 in the first embodiment shown in FIG. 3 in the X direction.

  In the outdoor heat exchanger 2010 of Comparative Example 2, since the length of the leeward fin region 2162 in the X direction is long, the frost is melted in the defrosting operation, and then the fan is operated again to start the frosting operation. The water droplets are discharged to the rear of the fins by the air flow, so that the drainage is relatively good. However, the first heat transfer tube 2021 and the second heat transfer tube 2022 are exposed on the windward side. As a result, there is a problem that the frost is spread from the exposed portion as a starting point, and the air passage is easily closed, and the frost resistance of the heat exchanger is not sufficient.

[Comparative Example 3]
FIG. 8 is an enlarged view of a main part of the outdoor heat exchanger according to Comparative Example 3. FIG. 8 shows a main part when the outdoor heat exchanger 3010 of Comparative Example 3 is observed in the Y direction. The outdoor heat exchanger 3010 is different from the outdoor heat exchanger 10 according to the first embodiment in that the length A3 of the upwind fin region 3161 in the X direction is equal to the length B3 of the downwind fin region 3162 in the X direction. It is a point. Therefore, after the frost is melted in the defrosting operation, even when the fan operates again and the frosting operation starts, the melted water droplets are discharged to the rear of the fins by the airflow, so that the drainage property is relatively good. . However, on the windward side, the first heat transfer tube 3021 and the second heat transfer tube 3022 are close to the windward fin end portion 3131, and the frost resistance as a heat exchanger is not sufficient.

  On the other hand, the outdoor heat exchanger 10 according to the first embodiment has the leeward fin region 162, as in Comparative Example 3, as shown in FIG. Therefore, even after the frost is melted in the defrosting operation and the fan is operated again to start the frosting operation, the melted water droplets are discharged to the rear of the fins by the airflow, so that the drainability is relatively good. Further, during the frosting operation, the length A of the leeward fin region 161 in the X direction is longer than the length B of the leeward fin region 162 in the X direction, so that the frost resistance is good.

  That is, according to the first embodiment, it is possible to improve both the drainage performance of the windward side heat exchanger 601 in the defrosting operation and the idea proof strength in the frosting operation. As described above, the leeward heat exchanger 602 also has the same configuration as the leeward heat exchanger 601. Therefore, also in the leeward heat exchanger 602, the same effect can be obtained.

  Furthermore, in the refrigeration cycle apparatus 501 including the outdoor heat exchanger 10 having a two-row structure in which the windward-side heat exchanger 601 and the leeward-side heat exchanger 602 are arranged in parallel, the time required for defrosting operation is shortened and the defrosting operation is eliminated. The amount of heat required for frost operation can be reduced. Further, the refrigeration cycle apparatus 501 according to Embodiment 1 reduces the residual water of the outdoor heat exchanger 10 during the frosting operation, and further delays the blockage of the air passage of the outdoor heat exchanger 10 during the frosting operation. As a result, it is possible to improve reliability, reduce ventilation resistance, and improve frost resistance. That is, according to the first embodiment, it is possible to improve the average heating capacity in the defrosting cycle of the refrigeration cycle apparatus 501.

Embodiment 2.
In the first embodiment, the first heat transfer pipe 21 and the second heat transfer pipe 22 are parallel to each other in the flow direction of the air supplied from the outdoor fan 506 and extend perpendicular to the Z direction which is the direction of gravity. It is located in. However, the angles of the first heat transfer tube 21 and the second heat transfer tube 22 are not limited to the configuration of the first embodiment. For example, as described below, the arrangement shown in the second embodiment may be used. In the second embodiment, items that are not particularly described are the same as those in the first embodiment, and the same functions and configurations will be described using the same reference numerals.

  FIG. 9 is an enlarged view of a main part of the outdoor heat exchanger according to the second embodiment of the present invention. Similar to FIG. 3, FIG. 9 shows a main part when the outdoor heat exchanger 10 is observed in the Y direction. The difference between the outdoor heat exchanger 10 according to the second embodiment and the first embodiment is that in the fin 31, the heat transfer tube is inclined downward in the gravity direction from the windward end toward the leeward end. That is the point. As shown in FIG. 9, the first heat transfer tube 21 is inclined such that the leeward side end 142 is located below the leeward side end 141 in the direction of gravity. Similarly, the second heat transfer tube 22 is inclined such that the leeward end 242 is located below the leeward end 241 in the direction of gravity. That is, the first heat transfer tube 21 is inclined downward from the windward end 141 toward the leeward end 142 in the gravity direction, and the second heat transfer tube 22 is moved from the windward end 241 to the leeward end. It inclines downward toward the gravity direction 242.

  Therefore, in the outdoor heat exchanger 10 according to the second embodiment, even when the air is not supplied from the outdoor fan 506 shown in FIG. 1, for example, even when the defrosting operation is performed, water droplets that melt on the heat transfer tube region 163 are gravity With the effect of the inclination of the first heat transfer pipe 21 and the second heat transfer pipe 22, it is possible to guide the heat transfer pipe to the leeward side and discharge it through the leeward fin region 162. Further, even when air is supplied from the outdoor fan 506, that is, even during the frosting operation after the defrosting operation, the first heat transfer pipe 21 and the second heat transfer tube 21 are inclined downward in the gravity direction along the wind direction of the airflow. Since the heat pipe 22 is arranged, it is possible to guide the water droplets to the leeward side and promote drainage. As described above, according to the second embodiment, the drainage property of the outdoor heat exchanger 10 can be improved.

Embodiment 3.
In Embodiment 1 and Embodiment 2, the outdoor heat exchanger 10 is a two-row configuration heat exchanger, and the windward side heat exchanger 601 and the leeward side heat exchanger 602 that constitute the outdoor heat exchanger 10 are the same. It has the configuration of. However, the configuration of the heat exchanger used in the present invention may be changed depending on the row. In the third embodiment, items not particularly described are the same as those in the first or second embodiment, and the same functions and configurations will be described using the same reference numerals.

  FIG. 10 is an enlarged view of a main part of the outdoor heat exchanger according to the third embodiment of the present invention. FIG. 10 shows essential parts when the windward side heat exchanger 601 and the leeward side heat exchanger 602 constituting the outdoor heat exchanger 10 are observed in the Y direction.

  The fins 31 of the windward heat exchanger 601 of the outdoor heat exchanger 10 according to the third embodiment have the same configuration as the fins 31 of the second embodiment. The difference between the outdoor heat exchanger 10 according to the third embodiment and the second embodiment is that the length A_2 in the X direction of the upwind fin region 161′ in the fins 32 of the downwind heat exchanger 602 is the upwind heat. This is a point that is shorter than the length A_1 of the upwind fin region 161 in the fin 31 of the exchanger 601 in the X direction.

  The outdoor heat exchanger 10 may adopt a bent configuration in order to improve the mounting efficiency when mounted on the outdoor unit. The leeward fin region 162 of the fin 31 of the windward heat exchanger 601 and the leeward fin region 161' of the fin 32 of the leeward heat exchanger 602 are regions facing each other. Therefore, when the outdoor heat exchanger 10 is bent, loads are likely to be applied to the leeward fin region 162 and the leeward fin region 161' from the respective directions, which may cause the fins 31 and 32 to buckle.

  As shown in FIG. 10, in the outdoor heat exchanger 10 according to the third embodiment, the length A_2 in the X direction of the upwind fin region 161′ in the fin 32 of the downwind heat exchanger 602 is set to the upwind heat exchange. It is configured to be shorter than the length A_1 of the upwind fin region 161 in the fin 31 of the container 601 in the X direction. Therefore, the buckling strength of the upwind fin region 161' in the fin 32 of the leeward heat exchanger 602 can be increased. Further, as in the second embodiment, in the fins 31 of the windward heat exchanger 601, since the length B_1 of the leeward fin region 162 in the X direction is shorter than the length A_1 of the upwind fin region 161 in the X direction, buckling occurs. The strength is relatively high. With the above configuration, when the outdoor heat exchanger 10 is bent and mounted on the outdoor unit, it is possible to provide the outdoor heat exchanger 10 in which the fins 31 and the fins 32 are less likely to buckle.

  Here, the frost resistance of the outdoor heat exchanger 10 according to the third embodiment will be described. During the heating operation, the air flowing through the outdoor heat exchanger 10 first strikes the windward heat exchanger 601. Then, the moisture contained in the air frosts on the windward side heat exchanger 601, and subsequently the air hits the leeward side heat exchanger 602. At this point, since the air is dehumidified to some extent, the amount of frost formed on the leeward heat exchanger 602 is smaller than the amount of frost formed on the leeward heat exchanger 601. Therefore, in the leeward side heat exchanger 602, even if only the length A_2 of the upwind fin region 161' of the fin 32 in the X direction is shortened, the influence on the frost resistance of the outdoor heat exchanger 10 is small.

  As described above, according to the third embodiment, it is possible to improve the manufacturability such as the buckling strength as compared with the related art while ensuring the frost resistance of the outdoor heat exchanger 10.

  Although FIG. 10 shows an example in which each heat transfer tube is inclined, the present invention is not limited to this. The length A_2 of the windward fin region 161′ of the fin 32 of the leeward heat exchanger 602 in the X direction is shorter than the length A_1 of the windward fin region 161 of the fin 31 of the windward heat exchanger 601 in the X direction. If so, each heat transfer tube need not be inclined.

Fourth Embodiment
FIG. 11 is an enlarged view of a main part of the outdoor heat exchanger according to Embodiment 4 of the present invention. As in Embodiments 1 to 3, in the fins 31 of the windward heat exchanger 601 of Embodiment 4, the length A_1 of the windward fin region 161 in the X direction is the X direction of the leeward fin region 162. Is longer than the length B_1. Further, the X direction length B_2 of the leeward fin region 162′ in the fin 33 of the leeward heat exchanger 602 is the same as the X direction length A_1 of the upwind fin region 161 in the fin 31 of the leeward heat exchanger 601. And the length A_2 in the X direction of the upwind fin region 161′ in the fin 33 of the leeward heat exchanger 602 is the length B_1 in the X direction of the leeward fin region 162 in the fin 31 of the upwind heat exchanger 601. Is the same as That is, the leeward heat exchanger 602 has a configuration in which the leeward heat exchanger 601 is vertically and horizontally inverted. In other words, in manufacturing the outdoor heat exchanger 10 having the two-row structure, the windward side heat exchanger 601 can be used as the leeward side heat exchanger 602 by arranging the windward side heat exchanger 601 vertically and horizontally. Therefore, it is not necessary to prepare equipment for manufacturing the leeward heat exchanger 602 in addition to equipment for manufacturing the leeward heat exchanger 601, and it is possible to suppress a rise in manufacturing cost.

  Although FIG. 11 shows an example in which each heat transfer tube is inclined, the present invention is not limited to this. In the fins 31 of the windward heat exchanger 601, the X-direction length A_1 of the leeward fin region 161 is longer than the X-direction length B_1 of the leeward fin region 162, and the leeward heat exchanger 602 indicates the windward side. As long as the heat exchanger 601 is vertically and horizontally inverted, the heat transfer tubes do not have to be inclined.

  As described above, in Embodiments 1 to 4 described above, the heat exchanger according to each embodiment is used as the outdoor heat exchanger 10, but the present invention is not limited to this. The heat exchangers of Embodiments 1 to 4 may be used as the indoor heat exchanger 503 shown in FIG. In that case, by reducing the amount of water retained in the indoor heat exchanger 503, the input of the indoor fan 504 can be reduced, and the energy consumption of the refrigeration cycle apparatus 501 can be reduced.

  10 Outdoor Heat Exchanger, 21 1st Heat Transfer Tube, 22 2nd Heat Transfer Tube, 30 Fins, 31 Fins, 32 Fins, 33 Fins, 131 Windward Fin Ends, 132 Downwind Fin Ends, 141 Windward Ends Section, 142 leeward side end, 151 first imaginary line, 152 second imaginary line, 161 leeward fin region, 161' leeward fin region, 162 leeward fin region, 162' leeward fin region, 163 heat transfer tube region , 163' heat transfer tube area, 241 windward end, 242 leeward end, 501 refrigeration cycle device, 502 compressor, 503 indoor heat exchanger, 504 indoor fan, 505 throttle device, 506 outdoor fan, 507 four-way valve, 601 leeward heat exchanger, 602 leeward heat exchanger, 603 leeward header collecting pipe, 604 leeward header collecting pipe, 605 inter-row connecting member, 1010 outdoor heat exchanger, 1021 first heat transfer pipe, 1022 second Heat transfer tube, 1132 leeward fin end, 1142 leeward fin end, 1161 leeward fin area, 1242 leeward end, 2010 outdoor heat exchanger, 2021 first heat transfer tube, 2022 second heat transfer tube, 2131 Windward fin end, 2141 windward end, 2162 leeward fin region, 2241 windward end, 3010 outdoor heat exchanger, 3021 first heat transfer tube, 3022 second heat transfer tube, 3131 windward fin end, 3161 Upwind fin area, 3162 Downwind fin area, FP Fin pitch interval.

Claims (3)

A heat exchanger to which air is supplied from a fan,
Plate-shaped fins,
A first heat transfer tube inserted into the fin and having a flat cross section;
A second heat transfer tube that is inserted into the fin, is arranged side by side in the direction of gravity with the first heat transfer tube spaced apart, and has a flat cross section;
A first wind upper end that is an end on the windward side of the first heat transfer tube in the air ventilation direction, and a second wind that is an end on the windward side of the second heat transfer tube in the air ventilation direction. The line connecting the upper end is the first virtual line,
A first wind lower end that is an end on the leeward side in the ventilation direction of the first heat transfer tube, and a second wind lower end that is an end on the leeward side in the ventilation direction of the second heat transfer tube. When the line connecting and is the second virtual line,
The fin is defined by an upwind fin region defined by the windward end of the fin in the ventilation direction and the first imaginary line, and the first imaginary line and the second imaginary line. And a leeward fin region defined by the second imaginary line and an end of the fin on the leeward side in the airflow direction,
The heat exchanger has a two-row structure heat exchanger having a windward heat exchanger arranged on the windward side in the ventilation direction and a leeward heat exchanger arranged on the leeward side in the ventilation direction. And
In the windward heat exchanger, the length of the leeward fin region along the ventilation direction is longer than the length of the leeward fin region along the ventilation direction,
The length along the ventilation direction of the upwind fin region in the leeward heat exchanger and the length along the ventilation direction of the downwind fin region in the upwind heat exchanger are equal,
A heat exchanger in which the length of the leeward fin region of the leeward heat exchanger along the ventilation direction is equal to the length of the leeward fin region of the leeward heat exchanger along the ventilation direction. The first heat transfer tube inclines in the direction of gravity from the first wind upper end toward the first wind lower end, and the second heat transfer tube extends from the second wind upper end to the first wind lower end. The heat exchanger according to claim 1 , wherein the heat exchanger is inclined toward the second wind lower end in the direction of gravity. A refrigeration cycle apparatus comprising the heat exchanger according to claim 1 or 2 , and a blower fan that supplies air to the heat exchanger.

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