JP6429902B2 - Air conditioner outdoor unit - Google Patents

Description

  The present invention relates to an outdoor unit for an air conditioner.

  Some outdoor units of air conditioners installed in buildings or commercial facilities have heat exchangers disposed on the back side and side surfaces, and a fan disposed on the upper surface side (for example, Patent Document 1). reference).

  The heat exchanger as described in Patent Document 1 includes a circular or flat heat transfer tube that induces a refrigerant, and a plurality of fins to which the heat transfer tubes are connected. This heat exchanger is bent so that the horizontal cross-sectional shape is L-shaped or U-shaped. The heat exchanger is mounted on the outdoor unit in a state where at least two of the heat exchangers are stacked in the vertical direction to form a heat exchange unit. In Patent Document 1, a holding member is disposed between an upper heat exchanger and a lower heat exchanger, and a lateral shift between the upper heat exchanger and the lower heat exchanger is avoided by a support plate provided on the holding member. ing.

JP 2009-79851 A

  However, in the heat exchange unit as described above, water generated by the defrosting operation may stay in the holding member. Therefore, in the heat exchange unit as described above, there is a problem in that the water accumulated during the heating operation after the defrosting freezes and grows and may cause damage to the heat transfer tube.

  The present invention has been made in order to solve the above-described problems, and provides an outdoor unit for a refrigerating and air-conditioning apparatus capable of avoiding freezing and growth of water accumulated by defrosting. The purpose is that.

An outdoor unit of an air conditioner according to the present invention includes a plurality of fin tube heat exchangers in which a plurality of rows of heat exchanger cores each including a plurality of heat radiation fins and a plurality of heat transfer tubes penetrating the plurality of heat radiation fins are stacked. And the plurality of fin tube heat exchangers are stacked in a vertical direction, and high-temperature and high-pressure gas refrigerant is supplied from the compressor to the plurality of fin tube heat exchangers. in the defrosting operation, the gas refrigerant of the high temperature and high pressure, of the plurality of heat transfer tubes, initially flows into the heat transfer tube arranged on the windward side of the contact portion of the plurality of finned tube heat exchanger, wherein The length of the refrigerant flow path formed by the heat transfer tubes arranged on the contact portion side is longer than the refrigerant flow path formed by other heat transfer tubes .

  According to the present invention, a high-temperature and high-pressure gas refrigerant is preferentially placed on the contact portion of a plurality of finned-tube heat exchangers that are located on the windward side where the most frost is attached and in which water during defrosting tends to stay Can be introduced and heated, so that it is possible to avoid the water accumulated by defrosting from freezing and growing.

It is a perspective view which shows roughly the external appearance structure of the outdoor unit 1 of the air conditioning apparatus which concerns on Embodiment 1 of this invention. It is a perspective view which shows roughly the internal structure of the outdoor unit 1 of the air conditioning apparatus which concerns on Embodiment 1 of this invention. It is a perspective view which shows roughly the internal structure of the outdoor unit 1 of the air conditioning apparatus which concerns on Embodiment 1 of this invention. It is the schematic which shows an example of the structure of the heat exchanger core 12 in the outdoor unit 1 of the air conditioning apparatus which concerns on Embodiment 1 of this invention. It is the schematic which shows an example which manufactures the heat exchange unit 6 from the heat exchanger core 12 in the outdoor unit 1 of the air conditioning apparatus which concerns on Embodiment 1 of this invention. In the outdoor unit 1 of the air conditioning apparatus which concerns on Embodiment 1 of this invention, it is the schematic which shows an example of the process of giving the bending process to the heat exchange unit 6, and making it U shape. The defrosting effect of the outdoor unit 1 of the air-conditioning apparatus according to Embodiment 1 of the present invention is compared with the defrosting effect of the prior art. 3 schematically shows an example of a refrigerant flow path configuration in a heat exchange unit 6 of an outdoor unit 1 of an air-conditioning apparatus according to Embodiment 2 of the present invention. The positional relationship of the contact part 11a and the windshield cover 17 in the heat exchange unit 6 of the outdoor unit 1 of the air conditioner concerning Embodiment 3 of this invention is shown roughly. It is the schematic which shows the external appearance of the heat exchange unit 6 of the outdoor unit 1 of the air conditioning apparatus which concerns on Embodiment 3 of this invention.

Embodiment 1 FIG.
The outdoor unit 1 of the air conditioning apparatus according to Embodiment 1 of the present invention will be described. FIG. 1 is a perspective view schematically showing an external configuration of the outdoor unit 1 of the air-conditioning apparatus according to Embodiment 1. As shown in FIG.

  The outdoor unit 1 functions as a heat source unit (heat source side unit), and has, for example, a large and vertically long outer structure. Although not shown, the outdoor unit 1 is connected to one or more load side units (use side units) such as indoor units via a refrigerant pipe.

  The front surface of the outdoor unit 1 is provided with a substantially flat upper front panel 3 and a lower front panel 4 that form the outer shell of the front surface of the outdoor unit 1. An electrical component box 23 to be described later is housed inside the upper front panel 3.

  On the left side surface of the outdoor unit 1, a left side panel 8 that constitutes an outline of the left side surface of the outdoor unit 1 is provided. The left side panel 8 includes a substantially flat front part in which a plurality of air suction ports 2 are formed, a left curved part formed on the left side of the front part, and a right curved part formed on the right side of the front part. It is a U-shaped plate-shaped member.

  On the right side surface of the outdoor unit 1, a right side panel 9 constituting the outline of the right side surface of the outdoor unit 1 is provided. Although not shown in the drawing, the right side panel 9 is similar to the left side panel 8 in that a substantially flat front part in which a plurality of air suction ports 2 are formed, a left curved part formed on the left side of the front part, and a front part It is a U-shaped plate-shaped member which has a right curved part formed in the right side.

  In other words, the plurality of air suction ports 2 described above are U-shaped heat exchange units including a first heat exchanger 6a, a second heat exchanger 6b, and a third heat exchanger 6c, which will be described in detail later. 6 is formed on the left side panel 8 and the right side panel 9 so as to cover the outer surface of the left side panel 6.

  Below the outdoor unit 1, a base panel 16 that constitutes a lower shell of the outdoor unit 1 is provided. The left side panel 8 and the right side panel 9 are fixed to the base panel 16 with, for example, screws.

  On the upper part of the outdoor unit 1, a fan guard 5 that constitutes an outer shell on the upper side of the outdoor unit 1 is provided. The fan guard 5 accommodates a fan 22 which will be described later, and an air outlet 7 is formed in the upper part of the fan guard 5.

  FIG. 2 is a perspective view schematically showing the internal structure of the outdoor unit 1 of the air-conditioning apparatus according to Embodiment 1. As shown in FIG. FIG. 2 is a perspective view of the outdoor unit 1 shown in FIG. 1 with the upper front panel 3 and the fan guard 5 removed.

  An electrical component box 23 is accommodated inside the upper front panel 3. The electrical component box 23 accommodates, for example, a control device that controls at least the operation and stop of the outdoor unit 1, various electrical components, boards, and the like.

  The outdoor unit 1 includes a left side frame 18 that supports the fan guard 5, a right side frame 19, a front frame 20, and a rear frame 21. The left side frame 18 is fixed to the upper end side of the left side panel 8. The right side frame 19 is fixed to the upper end side of the right side panel 9. The front frame 20 has a left end portion fixed to the left side panel 8 and a right end portion fixed to the right side panel 9. The rear frame 21 extends between the left side panel 8 and the right side panel 9, and is fixed to the upper end sides of the left side panel 8 and the right side panel 9.

  A fan 22 is accommodated inside the fan guard 5. By rotating the fan 22, air is sucked from the plurality of air suction ports 2, passes through the internal space of the outdoor unit 1, and is exhausted from the air outlet 7. The fan 22 is driven by a motor 22a (for example, an induction motor, a DC brushless motor, etc.).

  The motor 22a has, for example, two support members that extend between the front frame 20 and the rear frame 21, and an opening that is fixed to the two support members and that can fix the outer edge of the body of the motor 22a. It is fixed by the motor support 22b provided with the supporting plate which has. The fan 22 is disposed above the motor 22a and is supported by a motor support 22b.

  FIG. 3 is a perspective view schematically showing the internal structure of the outdoor unit 1 of the air-conditioning apparatus according to Embodiment 1. As shown in FIG. 3 is a front panel 4, a left side panel 8, a right side panel 9, a fan 22, a motor 22a, a motor support 22b, an electrical component box 23, a left side frame 18, a right side frame 19, It is the perspective view which removed the front frame 20, the rear frame 21, etc., and made the internal structure of the outdoor unit 1 clearer.

  As shown in FIG. 3, the outdoor unit 1 houses a compressor 24, an accumulator 25, a refrigerant pipe 26, and a refrigerant flow switching device 27 in addition to the heat exchange unit 6.

  The compressor 24 is a fluid machine that compresses sucked low-pressure refrigerant and discharges it as high-pressure refrigerant. In FIG. 3, the compressor 24 is surrounded by the heat exchange unit 6 and installed on the base panel 16. The suction port of the compressor 24 is connected to the accumulator 25 via the refrigerant pipe 26. Further, the discharge port of the compressor 24 is connected to the heat exchange unit 6 during cooling operation by a refrigerant flow switching device 27 described later, and load side heat mounted on a load side unit (for example, an indoor unit) during heating operation. Connected to an exchanger (not shown). The operating frequency of the compressor 24 is controlled by, for example, a control device accommodated in the electrical component box 23. The compressor 24 supplies a high-temperature and high-pressure gas refrigerant (hot gas) to the heat exchange unit 6 during the defrosting operation.

  Here, the cooling operation is an operation of supplying a low-temperature and low-pressure refrigerant to a load-side heat exchanger (not shown), and the heating operation is a high-temperature and high-pressure to the load-side heat exchanger (not shown). This is an operation for supplying the refrigerant.

  The defrosting operation is a hot gas (high-temperature high-pressure gas refrigerant) from the compressor 24 to the heat exchange unit 6 in order to melt the frost adhering during the heating operation when the outside air temperature is low (for example, minus 6 ° C.). It is a driving to supply. By the defrosting operation, frost and ice adhering to the heat exchange unit 6 are melted by the hot gas. In the outdoor unit 1, a bypass refrigerant pipe (not shown) is provided between the compressor 24 and the heat exchange unit 6 so that hot gas can be directly supplied from the compressor 24 to the heat exchange unit 6 during the defrosting operation. You may connect. Further, the hot gas may be supplied from the compressor 24 to the heat exchange unit 6 by connecting the discharge port of the compressor 24 to the heat exchange unit 6 via a refrigerant flow switching device 27 described later.

  The accumulator 25 stores liquid refrigerant, and is connected to the suction port of the compressor 24 via the refrigerant pipe 26 as described above. The accumulator 25 is surrounded by the heat exchange unit 6 and installed on the base panel 16.

  The refrigerant pipe 26 is a pipe that extends from the upper part of the accumulator 25 to the upper side and then extends to the lower side, and is connected to the suction port on the side surface of the compressor 24.

  The refrigerant flow switching device 27 switches the flow direction of the refrigerant in the refrigeration cycle during the cooling operation and the heating operation. For example, a four-way valve is used as the refrigerant flow switching device 27. During the heating operation, the refrigerant flow switching device 27 connects the discharge port of the compressor 24 and a load side heat exchanger (not shown) of the indoor unit, and connects the suction port of the compressor 24 and the heat exchange unit 6. Are connected. In addition, the refrigerant flow switching device 27 connects the discharge port of the compressor 24 and the heat exchange unit 6 during the cooling operation, and the intake port of the compressor 24 and the load side heat exchanger (not shown) of the indoor unit. ). Switching of the flow direction of the refrigerant in the refrigerant flow switching device 27 is performed by, for example, a control device accommodated in the electrical component box 23.

  Next, the heat exchange unit 6 according to Embodiment 1 will be described.

  The heat exchange unit 6 is configured by stacking a first heat exchanger 6a, a second heat exchanger 6b, and a third heat exchanger 6c in the vertical direction. The first heat exchanger 6a, the second heat exchanger 6b, and the third heat exchanger 6c function as a condenser (heat radiator) during the cooling operation and function as an evaporator during the heating operation. It is an exchanger.

  The first heat exchanger 6a, the second heat exchanger 6b, and the third heat exchanger 6c are bent at a substantially right angle to form a first bent portion 6d and a second bent portion 6e. Has been. That is, the 1st heat exchanger 6a, the 2nd heat exchanger 6b, and the 3rd heat exchanger 6c are formed so that a horizontal section shape may become U shape.

  FIG. 4 is a schematic diagram illustrating an example of the structure of the heat exchanger core 12 in the outdoor unit 1 of the air-conditioning apparatus according to Embodiment 1. The heat exchanger core 12 includes a plurality of rectangular radiating fins 11 extending in the vertical direction, and a plurality of U-shaped heat transfer tubes 10 that penetrate the plurality of fins and guide the refrigerant. Therefore, the 1st heat exchanger 6a, the 2nd heat exchanger 6b, and the 3rd heat exchanger 6c are the fins in which the heat exchanger core 12 shown in FIG. It becomes a tube-type heat exchanger.

  As shown in the dotted line part of FIG. 4, although the U-shaped flat tube is used as the heat exchanger tube 10 of the heat exchanger core 12, a circular tube may be sufficient. As shown in the end portion 10a of the heat transfer tube in FIG. 4, since the flat tube has a large number of paths formed inside the heat transfer tube 10, high fin heat transfer efficiency can be realized. The flat tube is made of, for example, aluminum or an aluminum alloy.

  Here, in the state where the heat exchange unit 6 is mounted on the outdoor unit 1, the direction perpendicular to the vertical direction of the radiation fin 11 and the thickness direction of the radiation fin 11 is defined as the width direction of the radiation fin 11. The heat transfer tube 10 of FIG. 4 which is a flat tube is inserted into the heat radiation fin 11 so that the width direction of the heat radiation fin 11 is the long axis direction of the heat transfer tube 10. In the heat exchanger core 12 of FIG. 4, the heat transfer tube 10 is inserted on one end side in the width direction of the radiation fin 11.

  FIG. 5 is a schematic diagram illustrating an example of manufacturing the heat exchange unit 6 from the heat exchanger core 12 in the outdoor unit 1 of the air-conditioning apparatus according to Embodiment 1.

  The heat dissipating fin 11 having a notch portion into which the heat transfer tube 10 shown in FIG. 4 can be inserted is manufactured by pressing a metal plate material with a mold having a preset shape. A plurality of radiating fins 11 having such notches are arranged in parallel at predetermined intervals, the heat transfer tubes 10 are inserted into the notches, and the heat transfer tubes 10 and the radiating fins 11 are brazed to exchange heat. The device core 12 is manufactured.

  Next, a plurality of rows of heat exchanger cores 12 are overlapped to manufacture the first heat exchanger 6a, the second heat exchanger 6b, and the third heat exchanger 6c. Here, as an example, a case is considered where two rows of heat exchanger cores 12 are overlapped to manufacture the first heat exchanger 6a, the second heat exchanger 6b, and the third heat exchanger 6c, respectively. In this example, since two rows of heat exchanger cores 12 are stacked in three stages, a total of six heat exchanger cores 12 constitute the heat exchange unit 6.

  As shown in FIG. 5, the third heat exchanger 6c, the second heat exchanger 6b, and the first heat exchanger 6a are stacked in order from the bottom. At this time, the lower end side of the radiating fin 11 of the heat exchanger core 12 of the second heat exchanger 6b and the upper end side of the radiating fin 11 of the heat exchanger core 12 of the third heat exchanger 6c are in contact with each other. In addition, the second heat exchanger 6b is stacked on the third heat exchanger 6c. Further, the lower end side of the heat dissipating fin 11 of the heat exchanger core 12 of the first heat exchanger 6a and the upper end side of the heat dissipating fin 11 of the heat exchanger core 12 of the second heat exchanger 6b are in contact with each other. The first heat exchanger 6a is stacked on the second heat exchanger 6b. As a result, as shown in the dotted line part of FIG. 5, the heat exchange unit 6 is between the first heat exchanger 6a and the second heat exchanger 6b and between the second heat exchanger 6b and the third heat exchanger 6b. A contact portion 11a is provided between the heat exchanger 6c and the heat exchanger 6c.

  FIG. 6 is a schematic diagram illustrating an example of a process of bending the heat exchange unit 6 into a U shape in the outdoor unit 1 of the air-conditioning apparatus according to Embodiment 1.

  As shown in FIG. 6, a U vent pipe 13 (U vent) is brazed and connected to the heat transfer pipe 10 of the first heat exchanger 6a, the second heat exchanger 6b, and the third heat exchanger 6c. Then, one or more refrigerant flow paths having an arbitrary length are formed in the heat exchange unit 6.

  At this time, in Embodiment 1, the U vent pipe 13 is not connected to the end portion 10a of the heat transfer tube disposed on the windward side of the contact portion 11a among the plurality of heat transfer tubes 10 of the heat exchange unit 6. In addition, a refrigerant flow path of the heat exchange unit 6 is formed. In the first embodiment, there are a total of four end portions 10a of the heat transfer tubes not connected to such a U vent tube 13.

  Next, in the first embodiment, the header pipe 14 (header) is brazed to the end portion 10 a of the heat transfer pipe to which the U vent pipe 13 is not connected, and the refrigerant flows into the refrigerant flow path of the heat exchange unit 6. So that they are connected.

  At this time, in Embodiment 1, high-temperature and high-pressure gas refrigerant flows into the end portions 10a of the four heat transfer tubes arranged on the windward side of the contact portion 11a during the defrosting operation.

  Next, the first heat exchanger 6a, the second heat exchanger 6b, and the third heat exchanger 6c are bent by using a bending machine (not shown) or the like, so that the first The heat exchange unit 6 having a U-shaped horizontal cross section in which the bent portion 6d and the second bent portion 6e are formed is manufactured.

  As described above, in the outdoor unit 1 of the air conditioner, the high-temperature and high-pressure gas refrigerant flows into the heat transfer tube 10 disposed on the windward side of the contact portion 11a.

  According to this configuration, the high-temperature and high-pressure gas refrigerant is preferentially caused to flow into the contact portion 11a that is located on the windward side where the most amount of frost is attached and in which water during defrosting tends to stay, and is heated. it can. Therefore, according to this configuration, it is possible to efficiently perform defrosting on the windward side of the contact portion 11a and melting of ice particles frozen by the water detained by the previous defrosting. It is possible to prevent the water staying on the upper side from freezing and growing. Further, the melting of the ice particles on the windward side of the contact portion 11a can be performed while the other path portion of the heat transfer tube 10 on the contact portion 11a side is defrosted. Therefore, according to this configuration, the defrosting operation can be performed without reducing the average heating capacity.

  FIG. 7 compares the defrosting effect of the outdoor unit 1 of the air-conditioning apparatus according to Embodiment 1 with the defrosting effect of the prior art.

  FIG. 7 compares the defrosting effect in the contact portion 11a between the first heat exchanger 6a and the second heat exchanger 6b as seen from the header pipe 14 side. FIG. 7 (a) shows the defrosting effect of the prior art, and FIG. 7 (b) shows the defrosting effect of the outdoor unit 1 of the air-conditioning apparatus according to Embodiment 1. Is shown. The black arrow at the bottom of FIG. 7 indicates the wind direction. A broken line arrow connecting the U vent pipe 13 and the end portion 10a of the heat transfer pipe schematically indicates the flow of the refrigerant during defrosting.

  In the prior art shown in FIG. 7 (a), the frost is removed from the contact portion 11a that is located on the windward side where the amount of frost adhering as indicated by the symbol A is the largest and in which water during defrosting tends to stay. By the time, the heat transfer tube 10 is reciprocated twice or more. Therefore, there has been a problem that the temperature of the hot gas is lowered before the defrosting of the portion indicated by the symbol A is performed, the defrosting time is extended, and the average heating capacity is lowered.

  On the other hand, in the outdoor unit 1 of the air-conditioning apparatus according to Embodiment 1 shown in FIG. 7 (b), a high temperature is generated on the windward side of the contact portion 11a having the largest frost adhesion amount indicated by reference symbol A. A high-pressure gas refrigerant can be directly introduced. Therefore, it is possible to efficiently perform defrosting at places where the possibility of freezing is high.

  Conventionally, there has been a problem that water tends to stay in a defrosting operation at a contact portion of a heat exchanger of a heat exchanger unit in which a plurality of heat exchangers are stacked due to the collapse and distortion of a radiation fin. Further, even when a support member is provided at the contact portion of the heat exchanger, there is a problem that frost tends to adhere because the support member impedes ventilation, and water is retained by the defrosting operation. In particular, on the windward side, there is a problem that the amount of frost attached is large, so that water stays more. Furthermore, when water stays in this way, the water freezes in the subsequent heating operation, and the ice gradually grows by repeating the operation and defrosting, which may cause damage to the heat transfer tube. there were.

  However, according to the above-described configuration of the first embodiment, it is possible to efficiently perform defrosting at a place where the possibility of freezing is high, and therefore icing due to water retention regardless of the presence or absence of a support member in the contact portion 11a. The problem can be solved.

  Moreover, as above-mentioned, high fin heat-transfer efficiency is realizable by using a flat tube as the heat-transfer tube 10 in this invention. On the other hand, a flat tube has a horizontal surface at the top, and has a problem that drainage is worse than a circular tube and is likely to freeze.

  Moreover, when manufacturing a heat exchanger using a flat tube, in order to reduce a manufacturing facility, the method of manufacturing the heat exchange unit 6 by stacking the heat exchanger cores 12 like this Embodiment 1 is main. Therefore, the problem of freezing due to water staying in the contact portion 11a is likely to occur.

  However, according to the configuration of the first embodiment, as described above, since the problem of freezing due to water retention is solved, the advantage of the flat tube that can achieve high fin heat transfer efficiency is maximized. You can save it.

  Moreover, since the manufacturing equipment of the heat exchanger using a flat tube can be reduced in size, it is possible to reduce the environmental load in the production process.

Embodiment 2. FIG.
The second embodiment of the present invention will be described below. FIG. 8 schematically shows an example of a refrigerant flow path configuration in the heat exchange unit 6 of the outdoor unit 1 of the air-conditioning apparatus according to Embodiment 2. FIG. 8 shows the refrigerant flow path configuration viewed from the header pipe 14 side in the first heat exchanger 6a and the second heat exchanger 6b. The black arrow at the bottom of FIG. 8 indicates the wind direction. A broken line arrow connecting the U vent pipe 13 and the end portion 10a of the heat transfer pipe schematically shows the flow of the refrigerant during the heating operation.

  In Embodiment 2, in the first heat exchanger 6a and the second heat exchanger 6b, the length of the refrigerant flow path on the contact portion 11a side (that is, the number of heat transfer tubes 10) is the other refrigerant flow. It is characterized by being longer than the road. In FIG. 8, in the first heat exchanger 6a and the second heat exchanger 6b, the number of heat transfer tubes 10 in the refrigerant flow path on the contact portion 11a side is eight, while the other refrigerant flow paths Then there are four. That is, the length of the refrigerant flow path formed by the heat transfer tubes 10 arranged on the contact portion 11 a side is longer than the refrigerant flow path formed by the other heat transfer tubes 10.

  Since a large amount of refrigerant flowing in from the header pipe 14 flows in a portion where the pressure loss is small, the refrigerant circulation amount flowing in the refrigerant flow path on the contact portion 11a side is increased by increasing the refrigerant flow path on the contact portion 11a side. This can be less than the amount of refrigerant circulating in the flow path. Therefore, in the second embodiment, the degree of superheat increases on the windward side of the contact portion 11a having the largest amount of frost attached as indicated by reference sign B, and the temperatures of the heat transfer tubes 10 and the radiation fins 11 on the windward side of the contact portion 11a. Will rise. As a result, the amount of frost attached to the contact portion 11a can be reduced.

Embodiment 3 FIG.
The third embodiment of the present invention will be described below. FIG. 9 schematically shows the positional relationship between the refrigerant flow path configuration and the windshield cover 17 in the heat exchange unit 6 of the outdoor unit 1 of the air-conditioning apparatus according to Embodiment 3. The refrigerant flow path configuration of FIG. 9 is the same as that of the above-described second embodiment, and the heat transfer tube 10 of the refrigerant flow path on the contact portion 11a side in the first heat exchanger 6a and the second heat exchanger 6b. While the number is eight, the other refrigerant channels have four. That is, the length of the refrigerant flow path provided with the heat transfer tube 10 disposed on the contact portion 11a side is longer than the length of the refrigerant flow path provided with the other heat transfer tubes 10. The black arrow at the bottom of FIG. 9 indicates the wind direction. A broken line arrow connecting the U vent pipe 13 and the end portion 10a of the heat transfer pipe schematically shows the flow of the refrigerant during the heating operation.

  As shown in FIG. 9, in the third embodiment, a windbreak cover 17 is provided on the windward side of the contact portion 11a of the second embodiment.

  In the portion indicated by the symbol C, the air volume at the contact portion 11a is reduced by providing the wind shield cover 17. However, since the length of the refrigerant flow path on the contact portion 11a side is longer than that of the other refrigerant flow paths, the degree of superheat increases on the windward side of the contact portion 11a, and the air volume decreases during heating operation. There is almost no influence by. On the other hand, in the part shown by the code | symbol C, since the water | moisture content supplied from external air reduces by the air volume falling, the adhesion amount of the frost 15 can be reduced.

  Here, d is the distance from the outer side of the heat exchanger core 12 on the windward side to the windbreak cover 17. In the third embodiment, by setting the distance d to 8 mm or more, it is possible to prevent the frost 15 generated in the contact portion 11 a from being frozen by the contact of the windshield cover 17.

  Next, the structure of the windshield cover 17 will be described. The windshield cover 17 can be configured to have a shape similar to the horizontal cross section of the heat exchange unit 6, for example. In other words, the windbreak cover 17 can be manufactured by bending a coated sheet metal or the like at a substantially right angle so that the horizontal cross section has a U-shape. Further, the windbreak cover 17 may be configured to contact the inside of the left side panel 8, the rear panel (not shown), and the right side panel 9 and have a U-shaped cross section.

  FIG. 10 is a schematic diagram showing an appearance of the heat exchange unit 6 of the outdoor unit 1 of the air-conditioning apparatus according to Embodiment 3. As shown in FIG. FIG. 10A shows the appearance of the heat exchange unit 6 before the windshield cover 17 is attached, and FIG. 10B shows the appearance of the heat exchange unit 6 after the windshield cover 17 is attached. In FIG. 10, the windshield cover 17 is configured to have a U shape similar to the horizontal section of the heat exchange unit 6.

  The windshield cover 17 may be installed so that the collapse and distortion of the heat radiation fins 11 in the contact portion 11a are not visible from the outer surface. For example, the panel member of the outdoor unit 1 such as the rear panel or the outdoor unit 1 such as the rear frame 21 may be used. You may fix to a frame member.

  In the heat exchange unit 6, the heat radiation fins 11 of the second heat exchanger 6b support the weight of the first heat exchanger 6a. Furthermore, the radiation fins 11 of the third heat exchanger 6c support the weights of the first heat exchanger 6a and the second heat exchanger 6b. Therefore, in the contact portion 11a, the radiating fins 11 are crushed and distorted due to vibration and drop impact during transportation, which may cause a design defect.

  In the third embodiment, as shown in FIG. 10B, by disposing the wind shield cover 17 along the contact portion 11a, the collapse and distortion of the heat radiation fin 11 in the contact portion 11a can be hidden from the outer surface. it can. Therefore, in this Embodiment 3, the problem of the design surface of the heat exchange unit 6 can be improved.

Other embodiments.
The present invention is not limited to the above-described embodiment, and various modifications can be made. For example, in the above-described embodiment, the outdoor unit 1 of the air conditioner is taken as an example, but the present invention can also be applied to a defrosting operation of an outdoor unit of a hot water supply device.

  In the above-described embodiment, the three-stage heat exchange unit 6 including the first heat exchanger 6a, the second heat exchanger 6b, and the third heat exchanger 6c is configured. Alternatively, the heat exchange unit 6 may be formed by stacking four or more heat exchangers.

  Moreover, the water surface cross-sectional shape of the heat exchange unit 6 is not limited to a U-shape, and may be an L-shaped heat exchange unit 6, for example.

  In each heat exchanger (that is, the first heat exchanger 6a, the second heat exchanger 6b, and the third heat exchanger 6c), the number of the heat exchanger cores 12 arranged in the column direction. Is not limited to two. The number of heat exchanger cores 12 arranged in the column direction may be one or three or more.

  Further, the windbreak cover 17 has such a width that the collapse and distortion of the radiating fins 11 in the contact portion 11a cannot be seen from the outer surface (for example, the end portion 10a of 2 to 6 heat transfer tubes centering on the contact portion 11a). It is good also as what has the width which can be covered) in the perpendicular direction.

  Further, the above-described embodiments can be used in combination with each other.

  DESCRIPTION OF SYMBOLS 1 Outdoor unit, 2 Air suction inlet, 3 Upper front panel, 4 Lower front panel, 5 Fan guard, 6 Heat exchange unit, 6a 1st heat exchanger, 6b 2nd heat exchanger, 6c 3rd Heat exchanger, 6d first bent portion, 6e second bent portion, 7 air outlet, 8 left side panel, 9 right side panel, 10 heat transfer tube, 10a end portion of heat transfer tube, 11 heat radiation fin, 11a Contact part, 12 Heat exchanger core, 13 U vent pipe, 14 Header pipe, 15 Frost, 16 Base panel, 17 Wind protection cover, 18 Left side frame, 19 Right side frame, 20 Front frame, 21 Rear frame, 22 Fan, 22a motor, 22b motor support, 23 electrical component box, 24 compressor, 25 accumulator, 26 refrigerant piping, 27 refrigerant flow switching device.

Claims (5)

A plurality of fin tube heat exchangers in which a plurality of heat exchanger cores each including a plurality of heat radiation fins and a plurality of heat transfer tubes penetrating the plurality of heat radiation fins are stacked;
A compressor and
The plurality of finned tube heat exchangers are stacked in a vertical direction,
During the defrosting operation in which high-temperature and high-pressure gas refrigerant is supplied from the compressor to the plurality of fin-tube heat exchangers, the high-temperature and high-pressure gas refrigerant is the plurality of fin tubes among the plurality of heat transfer tubes. initially it flows into the heat transfer tube arranged on the windward side of the contact portion of the mold heat exchanger,
The length of the refrigerant flow path formed by the heat transfer tubes arranged on the contact portion side is an outdoor unit of the air conditioner that is longer than the refrigerant flow paths formed by other heat transfer tubes . The outdoor unit of the air conditioner according to claim 1, further comprising a refrigerant flow switching device that switches a flow direction of the gas refrigerant, and switching to a heating operation after the defrosting operation is completed. The outdoor unit of the air conditioner according to claim 1 or 2 , wherein a windbreak cover is disposed on the windward side of the finned tube heat exchanger so as to cover the contact portion. The outdoor unit for an air conditioner according to claim 3 , wherein the wind shield cover is disposed 8 mm or more away from the contact portion in the windward direction. The outdoor unit for an air conditioner according to any one of claims 1 to 4 , wherein the plurality of heat transfer tubes are flat tubes, and the flat tubes are made of aluminum or an aluminum alloy.

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