JP5744219B2 - Outdoor unit - Google Patents

Description

The present invention is, for example, relates to an outdoor unit having a defrosting function.

  In the case of an air conditioner, the outdoor heat exchanger operates as an evaporator during heating operation, and in the case of a water heater, the air heat exchanger operates as an evaporator during hot water operation. These heat exchangers have a lower temperature than the air that exchanges heat, so they receive heat from the outdoor air and heat up to the indoor heat exchanger (water heat exchanger in the case of a water heater). Hot water operation).

  For example, when the temperature of the outdoor air is low (for example, a dry bulb temperature of 2 ° C. and a wet bulb temperature of 1 ° C. under the JIS heating low temperature condition), the surface temperature of the outdoor heat exchanger (air heat exchanger in the case of a water heater) is 0 The frosting phenomenon occurs, where moisture in the inflowing air becomes frost on the surface of the outdoor heat exchanger (air heat exchanger). "Low outdoor air conditions").

  In each heat exchanger described above, due to the frosting phenomenon, the ventilation resistance increases and the amount of inflow air decreases, so the capabilities of the air conditioner and the water heater decrease. Therefore, the air conditioner (water heater) performs a defrosting operation to remove the attached frost. As a defrosting method, there are generally a reverse method for an air conditioner and a hot gas method for a hot water heater. However, since the heating operation (hot water supply operation) is suspended during the defrosting operation, the comfort of the indoor heating is impaired, or the hot water storage temperature is lowered, and it is a problem to reduce the number of defrosting times under low outside air conditions. It has become.

  Conventionally, in order to solve the problem, the heat exchange surface (fin surface) of the outdoor heat exchanger is provided with a frosting suppression layer on the heat exchange surface that increases slidability and water repellency and suppresses frost formation. A method for suppressing frost formation in an outdoor heat exchanger under low outdoor air conditions has been proposed (see, for example, Patent Document 1).

  In addition, a technique has been proposed in which a refrigerant pipe for preventing freezing of drain water under a low outside air condition is provided in a drain pan that receives defrosted and melted water (drain water) generated during heating operation (for example, a patent). Reference 2).

JP 2002-323298 A (Abstract) Japanese Patent Laid-Open No. 60-60466 (2nd page, FIG. 3)

  However, in the frost suppression method described in Patent Document 1, there is a problem that frost and ice generated between the heat exchanger subjected to water sliding or water repellent treatment and the drain pan cannot be treated. Further, in the technique described in Patent Document 2, it is possible to prevent freezing in the drain pan by the refrigerant pipe disposed in the drain pan, but it is difficult to completely melt freezing of water dripping from the heat exchanger. there were.

The present invention has been made in order to solve the above-described problems, and is capable of reliably melting frost and ice generated between the heat exchanger and the drain pan without reducing the air flow rate to the heat exchanger. The purpose is to provide a machine .

The outdoor unit according to the present invention has at least a first heat exchanger, a compressor, and an expansion unit having a heat exchange surface subjected to water sliding or water repellent treatment, and a second heat exchange provided separately. A refrigerant circuit including a heat exchanger, a drain pan installed below the first heat exchanger, and between the first heat exchanger and the drain pan, disposed above the drain pan, and has a flat outer shape. A heating means having a shape and a blowing means for blowing outdoor air in parallel with the heat exchange surface of the first heat exchanger, and the heating means is operated when the first heat exchanger operates as an evaporator. The refrigerant flowing into the first heat exchanger is taken as a heat source, and the diameter is long in the direction of the flow of outdoor air from the blower, and the width in the long diameter direction is the outdoor air of the first heat exchanger The length in the flow direction is approximately the same as or longer than the depth, and there are a plurality of refrigerant flow paths inside. Vignetting was a flat tube.

  In the present invention, since a heating means having a flat external shape is arranged between the heat exchanger and the drain pan, the lower portion of the heat exchanger and the drain pan are not reduced without reducing the amount of ventilation to the heat exchanger. The frost and ice generated between them can be melted reliably.

It is a refrigerant circuit diagram which shows the refrigeration cycle apparatus of a general air conditioner. It is a schematic block diagram which shows the outdoor unit of FIG. It is a schematic block diagram which shows the installation position of the heating means provided in the outdoor unit of FIG. It is a schematic block diagram of the outdoor unit which shows the state of the space which arose between the outdoor heat exchanger and the drain pan by installation of a heating means. It is a schematic block diagram of the outdoor unit which shows the state of the space which arises between both, when a heating means is each installed in the lower part of the outdoor heat exchanger of 2 rows. It is sectional drawing which shows the schematic block diagram of the outdoor unit which concerns on Embodiment 1, and the shape of the heating means provided in the outdoor unit. 6 is a refrigerant circuit diagram illustrating a refrigeration cycle apparatus for an air conditioner according to Embodiment 2. FIG. 6 is a refrigerant circuit diagram illustrating a refrigeration cycle apparatus for an air conditioner according to Embodiment 3. FIG. 6 is a refrigerant circuit diagram illustrating a refrigeration cycle apparatus for an air conditioner according to Embodiment 4. FIG.

Hereinafter, embodiments of an outdoor unit according to the present invention will be described. Before describing Embodiment 1 of the present invention, a general air conditioner refrigeration cycle apparatus and an outdoor unit used in the refrigeration cycle apparatus will be described.
FIG. 1 is a refrigerant circuit diagram showing a refrigeration cycle apparatus of a general air conditioner.

  As shown in FIG. 1, the general air conditioner includes an indoor unit 11 and an outdoor unit 12 that forms a refrigerant circuit with the indoor unit 11. The indoor unit 11 includes an indoor heat exchanger 22, an indoor blower fan 23, and the like. The outdoor unit 12 includes a compressor 21, a four-way valve 27 for switching between cooling operation / heating operation, an outdoor heat exchanger 25, an outdoor fan 26, a first expansion unit 24, a second expansion unit 28, and the like. ing. In the cooling operation, the indoor heat exchanger 22 operates as an evaporator, and the outdoor heat exchanger 25 operates as a condenser. In the heating operation, the indoor heat exchanger 22 operates as a condenser, and the outdoor heat exchanger 25 operates as an evaporator. The heat exchange surface (fin surface) of the outdoor heat exchanger 25 is subjected to water sliding or water repellent treatment.

  The first expansion means 24 includes, for example, an expansion valve that converts the high-pressure liquid refrigerant flowing from the indoor unit 11 during the heating operation into a medium-pressure gas-liquid two-phase refrigerant. The second expansion means 28 uniformly distributes the medium-pressure gas-liquid two-phase refrigerant flowing in through the first expansion means 24 during the heating operation, and lowers the refrigerant to the outdoor heat exchanger 25. For example, it consists of a capillary tube to be fed. In the case of the refrigeration cycle apparatus provided with a receiver for storing the refrigerant liquid, the second expansion means 28 described above uses an expansion valve equivalent to the first expansion means 24.

  In the air conditioner configured as described above, when the heating operation is performed, the refrigerant in the refrigeration cycle apparatus is compressed by the compressor 21 and flows into the indoor heat exchanger 22 as a high-temperature and high-pressure gas refrigerant. . The gas refrigerant exchanges heat (radiates heat) with the indoor air sent by the indoor fan 23 in the indoor heat exchanger 22 and becomes a high-pressure liquid refrigerant. Thereafter, the liquid refrigerant is expanded to a predetermined pressure by the first expansion means 24 and the second expansion means 28 to become a low-pressure gas-liquid two-phase refrigerant and flows into the outdoor heat exchanger 25. The gas-liquid two-phase refrigerant that has flowed into the outdoor heat exchanger 25 exchanges heat (absorbs heat) with the outdoor air sent by the outdoor fan 26 and returns to the compressor 21 as a low-temperature and low-pressure gas refrigerant.

Next, the structure of the outdoor unit of the air conditioner shown in FIG. 1 will be described.
FIG. 2 is a schematic configuration diagram showing the outdoor unit of FIG. 2A is a rear view showing the interior of the outdoor unit as viewed from the back, FIG. 2B is a left side view of the interior of the outdoor unit as viewed from the left side, and FIG. 2C is a diagram of the outdoor unit. The right side view showing the interior from the right side, and FIG. 4D is a plan view showing the bottom of the outdoor unit from above.

  In the outdoor unit 12, each component of the refrigerant circuit such as the compressor 21, the four-way valve 27, the outdoor heat exchanger 25, the outdoor fan 26, the first expansion unit 24, the second expansion unit 28, and the like described above is a unit. Arranged in the case 31. In addition to the components, a drain pan 32 is provided at the bottom of the unit case 31. The drain pan 32 is formed in a dish shape for receiving drain water generated by the outdoor heat exchanger 25, and is provided with a drain hole 33 for draining the drain water to the outside of the unit case 31. Generally, one, two, or more drain holes 33 are provided below the outdoor heat exchanger 25.

  The outdoor heat exchanger 25 of the outdoor unit 12 configured as described above is subjected to water sliding or water repellent treatment, thereby suppressing frost formation of the outdoor heat exchanger 25 that occurs under low outdoor air conditions. Specifically, when the outdoor heat exchanger 25 is operated as an evaporator under low outdoor air conditions, the condensed water (water droplets) generated on the outdoor heat exchanger 25 is solidified before frosting. Water droplets are dropped from above the outdoor heat exchanger 25 by sliding or water repellent treatment. Thereby, the amount of water droplets (ice droplets) adhering to the outdoor heat exchanger 25 is reduced, and the amount of frost formation is reduced.

  However, when the state of frost formation / defrosting of the outdoor heat exchanger 25 that has been subjected to water sliding or water repellent treatment under low outdoor air conditions is observed, the outdoor heat exchanger 25 is subjected to dripping of water droplets due to water sliding or water repellent treatment. It was confirmed that frost was generated between the lower part and the drain pan 32, which grew to become ice. When the frost and ice are not melted and the defrosting operation is terminated and the heating operation is performed, the frost and ice grow from the lower part of the outdoor heat exchanger 25, and the ventilation rate of the outdoor heat exchanger 25 is reduced. . In other words, in the outdoor heat exchanger 25 that has been subjected to water sliding or water repellent treatment, if frost and ice are reliably melted and discharged from the drain hole 33 of the drain pan 32, the amount of frost formed by the water sliding or water repellent treatment can be reduced. Therefore, it is possible to improve the performance of the refrigeration cycle apparatus under low outside air conditions.

Next, the heating means for melting frost and ice will be described.
FIG. 3 is a schematic diagram showing the installation position of the heating means provided in the outdoor unit of FIG. 3A is a front view showing the inside of the outdoor unit as viewed from the front, FIG. 3B is a left side view showing the inside of the outdoor unit as viewed from the left side, and FIG. 3C is a view of the outdoor unit. It is a top view which shows a bottom part seeing from upper direction.

  As shown in FIG. 3, the heating means 41 is composed of a circular refrigerant pipe. The installation position of the heating means 41 is based on the above-described knowledge, because frost and ice are generated between the lower part (lowermost fin) of the outdoor heat exchanger 25 and the drain pan 32. It can be seen that the drain pan 32 is preferably above the drain pan 32.

However, when the heating means 41 is installed between the lower part of the outdoor heat exchanger 25 and the drain pan 32 , a space 51 is required between the outdoor heat exchanger 25 and the drain pan 32 as shown in FIG. With this space 51, a part of the outdoor air blown from the outdoor fan 26 to the outdoor heat exchanger 25 passes through the space 51. Therefore, the amount of ventilation to the outdoor heat exchanger 25 decreases, and the heat exchange amount of the outdoor heat exchanger 25 decreases.

Moreover, when the outdoor heat exchanger 25 is a heat exchanger of 2 rows or 3 rows, the heating means 41 is needed directly under each row. In that case, as shown in FIG. 5, a space 52 is formed between the heating means 41, and frost and ice are generated in the lower portion of the space 52 and cannot be melted. Further, if one heating means 41 is used to deal with a plurality of rows of heat exchangers, the diameter of the heating means 41 increases, and accordingly, the space 51 between the outdoor heat exchanger 25 and the drain pan 32 also increases. Become.

  Moreover, when the diameter of the heating means 41 is increased, when the height of the outdoor unit 12 is limited, the height of the outdoor heat exchanger 25 is reduced, and the area of the heat exchanger is reduced. In that case, in order to ensure an equivalent area, the width of the unit case 31 of the outdoor unit 12 must be widened, and the outdoor unit 12 cannot be made compact.

Embodiment 1 FIG.
Here, the embodiment of the outdoor unit 12 provided with the heating means optimal for defrosting from the above viewpoint will be described.
FIG. 6 is a schematic configuration diagram of the outdoor unit according to Embodiment 1 and a cross-sectional view showing the shape of the heating means provided in the outdoor unit. FIG. 6A is a front view showing the inside of the outdoor unit as seen from the front, and FIG. 6B is a left side view showing the inside of the outdoor unit as seen from the left side. FIG. 4C shows a cross section of the heating means, and FIG. 4D shows a modification of the heating means.

  The outdoor unit 12 in the first embodiment includes a compressor 21, a four-way valve 27, an outdoor heat exchanger 25 (first heat exchanger), an outdoor fan 26, Each component of the refrigerant circuit such as the first expansion means 24 and the second expansion means 28 and the heating means 61 are provided. A drain pan 32 having a drain hole 33 is provided at the bottom of the unit case 31. The heating means 61 is disposed between the lower part (lowermost fin) of the outdoor heat exchanger 25 and the drain pan 32 and above the drain pan 32.

  The heating means 61 is composed of a flat tube having a long diameter in the direction of the air flow from the outdoor blower fan 26 orthogonal to the outdoor heat exchanger 25. The direction in which the diameter of the flat tube is long is defined as a width D, which is substantially the same as the depth of the outdoor heat exchanger 25 in the direction of the air flow. By using the flat tube, the height H can be kept low with respect to the width D, and the generation of the space 51 can be eliminated. Moreover, it is possible to suppress ventilation resistance by making the flat direction of the flat tube parallel to the air flow. As a heat source for the heating means, any one of a medium-pressure gas-liquid two-phase refrigerant, a high-pressure liquid refrigerant, and a high-temperature / high-pressure gas refrigerant is used.

By using a flat tube for the heating means 61, it is possible to suppress a height at which an outside area equivalent to that of a plurality of circular tubes can be achieved, and it is not necessary to increase the depth of the outdoor heat exchanger 25. Also, for the outdoor heat exchanger 25 in two rows and three rows, the flattening ratio of the flat tube (ratio of width D to height H) and a plurality of refrigerant flows inside as shown in FIG. By adopting a flat tube having a path, the same heating is possible even when the number of columns of the outdoor heat exchanger 25 is increased.

  In Embodiment 1, the heating means 61 is installed between the lower part of the outdoor heat exchanger 25 and the drain pan 32, and the ambient temperature between the lower part of the outdoor heat exchanger 25 and the drain pan 32 is set to 0 ° C. or higher by the refrigerant. By maintaining the temperature, the frost and ice generated between the lower portion of the outdoor heat exchanger 25 and the drain pan 32 are melted even under low outdoor air conditions without reducing the amount of ventilation to the outdoor heat exchanger 25. be able to.

  In addition, although it is desirable to make the width | variety D of a flat tube equal to the depth of the outdoor heat exchanger 25, the effect mentioned above is fully acquired even if it becomes beyond it.

Embodiment 2. FIG.
Next, an air conditioner including the outdoor unit 12 described in Embodiment 1 will be described.
FIG. 7 is a refrigerant circuit diagram showing a refrigeration cycle apparatus for an air conditioner according to Embodiment 2.
The air conditioner according to Embodiment 2 includes an indoor unit 11 and an outdoor unit 12 that forms a refrigerant circuit with the indoor unit 11, as in FIG. 1. The indoor unit 11 includes an indoor heat exchanger 22 (second heat exchanger), an indoor fan 23, and the like. The outdoor unit 12 includes a compressor 21, a four-way valve 27 for switching between cooling operation / heating operation, an outdoor heat exchanger 25 (first heat exchanger), an outdoor fan 26, a first expansion means 24, 2 expansion means 28, heating means 61, and the like.

  The heating means 61 is composed of a flat tube as shown in FIG. 6C, and as shown in FIGS. 6A and 6B, the lower part of the outdoor heat exchanger 25 (final fin), the drain pan 32, It is installed between. The heating means 61 is inserted into the refrigerant pipe between the first expansion means 24 and the second expansion means 28. With this connection, the medium-pressure gas-liquid two-phase refrigerant flows through the heating means 61 during the heating operation.

  In the air conditioner configured as described above, during the heating operation, the high-pressure liquid refrigerant flowing out of the indoor heat exchanger 22 becomes a medium-pressure gas-liquid two-phase refrigerant by the first expansion means 24, and the heating means It passes through 61 and becomes a low-pressure gas-liquid two-phase refrigerant by the second expansion means 28. Then, the refrigerant flows into the outdoor heat exchanger 25 and becomes a low-temperature and low-pressure gas refrigerant, and returns to the compressor 21 via the four-way valve 27. On the other hand, the heating means 61 uses an intermediate-pressure gas-liquid two-phase refrigerant as a heat source, sets the ambient temperature to 0 ° C. or higher, melts frost and ice generated in the outdoor heat exchanger 25, and maintains the state.

  As described above, in the second embodiment, the flat tube heating means 61 is installed between the lower part (lowermost fin) of the outdoor heat exchanger 25 and the drain pan 32. The frost and ice generated in the outdoor heat exchanger 25 can be reliably melted and the state maintained without reducing the air flow rate. Therefore, the operation can be continued without stopping the heating operation under the low outside air condition, and the comfort of the indoor heating is improved. Further, the defrosting time can be shortened, and the power consumption can be reduced accordingly.

Embodiment 3 FIG.
FIG. 8 is a refrigerant circuit diagram showing a refrigeration cycle apparatus for an air conditioner according to Embodiment 3. In the present embodiment, an outdoor unit 12 different from the second embodiment will be described.
The outdoor unit 12 in the third embodiment includes a compressor 21, a four-way valve 27, an outdoor heat exchanger 25 (first heat exchanger), an outdoor fan 26, and one first expansion means 24 (expansion valve). Two check valves 71a and 71b, a heating means 61 and the like are provided.

  A first expansion means 24 and a check valve 71 a are connected to a refrigerant pipe connecting the indoor heat exchanger 22 (second heat exchanger) and the outdoor heat exchanger 25. The heating means 61 is constituted by a flat tube as described above, and is installed between the lower part (lowermost fin) of the outdoor heat exchanger 25 and the drain pan 32. One end of the heating means 61 is connected to a refrigerant pipe between the first expansion means 24 and the check valve 71a via a conduit, and the other end is a refrigerant between the indoor heat exchanger 22 and the first expansion means 24. It is connected to a pipe branching from the pipe. A check valve 71b is connected to the pipe line. The aforementioned check valve 71a blocks high-pressure liquid refrigerant flowing from the indoor heat exchanger 22 during heating operation. The check valve 71 b prevents low-pressure gas-liquid two-phase refrigerant from flowing from the first expansion means 24 to the heating means 61 during the cooling operation.

  In the air conditioner configured as described above, during the heating operation, the high-pressure liquid refrigerant flowing out of the indoor heat exchanger 22 flows into the other check valve 71b by the check valve 71a, and the heating means 61 is turned on. The first expansion means 24 passes through and becomes a low-pressure gas-liquid two-phase refrigerant and flows into the outdoor heat exchanger 25. Then, the refrigerant flows into the outdoor heat exchanger 25 and becomes a low-temperature and low-pressure gas refrigerant, and returns to the compressor 21 via the four-way valve 27. On the other hand, the heating means 61 uses a high-pressure liquid refrigerant as a heat source, sets the ambient temperature to 0 ° C. or higher, melts frost and ice generated in the outdoor heat exchanger 25, and maintains the state.

  As described above, in the third embodiment, since the flat tube heating means 61 is installed between the lower part (lowermost fin) of the outdoor heat exchanger 25 and the drain pan 32, the outdoor heat exchanger 25 is moved to the outdoor heat exchanger 25. The frost and ice generated in the outdoor heat exchanger 25 can be reliably melted and the state maintained without reducing the air flow rate. Therefore, the operation can be continued without stopping the heating operation under the low outside air condition, and the comfort of the indoor heating is improved. Further, the defrosting time can be shortened, and the power consumption can be reduced accordingly.

Embodiment 4 FIG.
FIG. 9 is a refrigerant circuit diagram illustrating a refrigeration cycle apparatus for an air conditioner according to Embodiment 4. In the present embodiment, an outdoor unit 12 different from the second and third embodiments will be described. The outdoor unit 12 in the fourth embodiment includes a compressor 21, a four-way valve 27, an outdoor heat exchanger 25 (first heat exchanger), an outdoor fan 26, and one first expansion means 24 (expansion valve). And an on-off valve 81, a heating means 61, and the like.

  The heating means 61 is constituted by a flat tube as described above, and is installed between the lower part (lowermost fin) of the outdoor heat exchanger 25 and the drain pan 32. One end of the heating means 61 is connected to a pipe branching from the refrigerant pipe between the indoor heat exchanger 22 (second heat exchanger) and the first expansion means 24, and the other end is hot gas via the pipe. It is connected to the bypass pipe 82. The hot gas bypass pipe 82 has an on-off valve 81 and is connected to the discharge port side of the compressor 21. The on-off valve 81 opens the valve during heating operation. The opening / closing of the on-off valve 81 is performed by control of a control circuit of the air conditioner, although not shown in FIG.

  In the air conditioner configured as described above, a part of the high-temperature and high-pressure gas refrigerant discharged from the compressor during the heating operation flows into the hot gas bypass pipe 82, passes through the heating means 61, and the first The expansion means 24 becomes a low-pressure gas-liquid two-phase refrigerant and flows into the outdoor heat exchanger 25. Then, the refrigerant flows into the outdoor heat exchanger 25 and becomes a low-temperature and low-pressure gas refrigerant, and returns to the compressor 21 via the four-way valve 27. On the other hand, the heating means 61 uses a high-temperature and high-pressure gas refrigerant as a heat source, sets the ambient temperature to 0 ° C. or higher, melts frost and ice generated in the outdoor heat exchanger 25, and maintains the state.

  As described above, in the fourth embodiment, the flat tube heating means 61 is installed between the lower part (lowermost fin) of the outdoor heat exchanger 25 and the drain pan 32. The frost and ice generated in the outdoor heat exchanger 25 can be reliably melted and the state maintained without reducing the air flow rate. Therefore, the operation can be continued without stopping the heating operation under the low outside air condition, and the comfort of the indoor heating is improved. Further, the defrosting time can be shortened, and the power consumption can be reduced accordingly.

  In general, R410A is used as the refrigerant of the air conditioner, but in Embodiments 1 to 4, R32 having a higher gas specific heat ratio than R410A is used as the refrigerant. Thus, by using a refrigerant having a higher gas specific heat ratio than R410A, it is possible to increase the heating capacity when the refrigerant is used as a hot gas, and to reliably melt frost and ice generated in the outdoor heat exchanger 25. can do. The above effect is not only when R32 is used as a refrigerant. For example, even when a mixed refrigerant of R32 and HFO123yf having a gas specific heat ratio higher than that of R410A is used, the refrigerant is similarly converted into hot gas. The heating capacity when used as can be increased, and frost and ice generated in the outdoor heat exchanger 25 can be reliably melted.

Embodiment 5 FIG.
In Embodiment 2-4 mentioned above, although the outdoor unit 12 of Embodiment 1 was used for the air conditioner, this Embodiment used the outdoor unit 12 as the hot water heater (heat pump type hot water heater). Is applied.
For example, when the refrigeration cycle apparatus of FIG. 7 is used as a hot water heater, the four-way valve 27 is removed, and the indoor heat exchanger 22 of the indoor unit 11 is used as the water heat exchanger 22 and connected to the discharge port side of the compressor 21. Moreover, the outdoor heat exchanger 25 (air heat exchanger 25) of the outdoor unit 12 is connected to the inlet side of the compressor. During the hot water supply operation, cold water flowing through the water pipe is exchanged with the water heat exchanger 22 to form high temperature water, and the hot water is stored in a hot water storage tank (not shown).

In the water heater configured as described above, during the hot water supply operation, the high-pressure liquid refrigerant flowing out of the water heat exchanger 22 becomes a medium-pressure gas-liquid two-phase refrigerant by the first expansion means 24, and the heating means 61. And the second expansion means 28 becomes a low-pressure gas-liquid two-phase refrigerant. Then, the refrigerant flows into the air heat exchanger 25 and becomes a low-temperature and low-pressure gas refrigerant and returns to the compressor 21. On the other hand, the heating means 61 of the flat tube installed between the lower part (lowermost fin) of the air heat exchanger 25 and the drain pan 32 uses a medium-pressure gas-liquid two-phase refrigerant as a heat source, and the ambient temperature is 0. The frost and ice generated in the air heat exchanger 25 are melted and the state is maintained.

As described above, in the fifth embodiment, the flat tube heating means 61 is installed between the lower portion (lowermost fin) of the air heat exchanger 25 and the drain pan 32. without reducing the ventilation quantity, the frost and ice generated in the air heat exchange exchanger 25 surely melted, it is possible to maintain that state. Therefore, the operation can be continued without stopping the hot water supply operation under the low outside air condition, and a stable hot water storage can be obtained. Further, the defrosting time can be shortened, and the power consumption can be reduced accordingly.

In the fifth embodiment, the refrigeration cycle apparatus of FIG. 7 is applied to a water heater, but the refrigeration cycle apparatus shown in FIGS. 8 and 9 can also be used as a water heater.
In the first to fifth embodiments, the heating means 61 using the refrigerant flowing into the outdoor heat exchanger (air heat exchanger) 25 as the heat source has been described. Instead, the outdoor heat exchanger (air heat exchange) The electric heater may be disposed between the lower portion of the device 25 and the drain pan 32 and above the drain pan 32.

  DESCRIPTION OF SYMBOLS 11 Indoor unit, 12 Outdoor unit, 21 Compressor, 22 Indoor heat exchanger (water heat exchanger), 23 Indoor ventilation fan, 24 1st expansion means, 25 Outdoor heat exchanger (air heat exchanger), 26 Outdoor fan, 27 four-way valve, 28 second expansion means, 31 unit case, 32 drain pan, 33 drain hole, 41 heating means, 51 space, 52 space between heating means, 61 heating means, 71a, 71b reverse Stop valve, 81 Open / close valve, 82 Hot gas bypass pipe.

Claims (6)

A refrigerant circuit including at least a first heat exchanger, a compressor, and an expansion unit that are subjected to water sliding or water repellent treatment on the heat exchange surface and including a separately provided second heat exchanger When,
A drain pan installed below the first heat exchanger;
A heating means disposed between the first heat exchanger and the drain pan and disposed above the drain pan, and having a flat external shape;
A blowing means for blowing outdoor air in parallel with the heat exchange surface of the first heat exchanger;
The heating means takes in the refrigerant flowing into the first heat exchanger when the first heat exchanger is operating as an evaporator, serves as a heat source, and the flow of outdoor air from the blower means The diameter in the direction is long, and the width in the direction in which the diameter is long is substantially the same as or longer than the depth in the flow direction of the outdoor air of the first heat exchanger, and a plurality of refrigerant flow paths are provided inside. An outdoor unit characterized by being a flat tube.   The outdoor unit according to claim 1, wherein the heat source of the heating means is a gas-liquid two-phase refrigerant.   The outdoor unit according to claim 1, wherein a heat source of the heating means is a liquid refrigerant.   The outdoor unit according to claim 1, wherein a heat source of the heating means is a gas refrigerant.   The outdoor unit according to claim 1, wherein R32 refrigerant is used as the refrigerant.   The outdoor unit according to claim 1, wherein the refrigerant is a mixed refrigerant of R32 and HFO1234yf.

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