JP6557085B2 - Air conditioner - Google Patents

Description

  The present invention relates to an air conditioner that prevents freezing of drain water accumulated in an outdoor unit.

  In an air conditioner having an indoor unit and an outdoor unit, defrosting operation is performed when frost forms on the outdoor heat exchanger during heating operation. The drain water generated by the defrosting operation is dripped from the outdoor heat exchanger and collected on the bottom plate of the cabinet of the outdoor unit, and the drain water is discharged to the outside through a drain hole formed on the bottom surface.

  Here, when the outside air temperature is low, the drain water may freeze. When the drain water freezes, the drain water is not drained, and the ice on the bottom plate of the cabinet grows, adversely affecting the outdoor heat exchanger and the outdoor fan. In order to prevent the drain water from freezing, Patent Document 1 discloses a heat pipe formed by arranging a pipe through which a refrigerant flows below an outdoor heat exchanger. Further, Patent Document 2 describes that a heater is disposed below the outdoor heat exchanger.

Japanese Patent No. 4892713 Japanese Patent No. 3882910

  Freezing of drain water that has dropped below the outdoor heat exchanger is prevented by the heat of the heat pipe and the heater. However, when drain water flows out from the lower side of the outdoor heat exchanger, heat from the heat pipe and the heater does not reach and the drain water cannot be prevented from freezing. If the drain water freezes between the outdoor heat exchanger and the outdoor fan and the ice grows, the ice may come into contact with the outdoor fan.

  In view of the above, an object of the present invention is to provide an air conditioner that can prevent the drain water from freezing not only below the heat exchanger but also between the heat exchanger and the fan.

  The air conditioner of the present invention is a cabinet in which a heat exchanger and a fan are installed, and the heat exchanger is arranged on the windward side of the fan, and is dropped from the heat exchanger below the heat exchanger. A heating unit for preventing the drain water from freezing is provided, and a part of the heating unit is disposed between the heat exchanger and the fan in order to prevent the drain water from freezing between the heat exchanger and the fan.

  When the defrosting operation is performed during the heating operation, drain water is generated and collected below the heat exchanger. The heat generated from the heating unit prevents the drain water below the heat exchanger from freezing. And also with respect to the drain water which flowed outside the heat exchanger, the freezing of the drain water is prevented by the heat of the heating unit between the heat exchanger and the fan.

  The drainage hole formed below the heat exchanger is located between the heat exchanger and the fan, and the heating unit is disposed on the windward side of the drainage hole. That is, the heating unit is not provided on the leeward side of the drain hole. The drain water below the heat exchanger is discharged from the drain hole. When drain water freezes, ice may grow toward the fan, but the ice that grows toward the fan is melted by the heating unit.

  The heating part is a heat pipe using a pipe through which the refrigerant circulates, the pipe on the outlet side of the heat pipe is arranged below the heat exchanger, the high-temperature refrigerant flows through the pipe on the inlet side of the heat pipe, and the heat pipe A part of the pipe on the inlet side of the heat pipe is below the heat exchanger so that the low-temperature refrigerant flows out of the pipe on the outlet side of the heat pipe and the heat of the pipe on the inlet side of the heat pipe is transferred to the lower part of the heat exchanger. Pass through. Heat is dissipated while the refrigerant flows through the heat pipe, and the temperature of the refrigerant passing through the piping on the outlet side decreases. Since the heat of the piping on the inlet side is transmitted to the piping on the outlet side, the temperature of the piping on the outlet side can be increased, and the formation of ice below the heat exchanger can be suppressed.

  The heating unit is a heat pipe that uses a pipe through which the refrigerant circulates, and includes a cooling capacity reduction suppression mechanism that prevents a reduction in cooling capacity due to a pressure loss of the refrigerant flowing through the heat pipe. By reducing the pressure loss of the refrigerant flowing through the heat pipe, the cooling capacity can be prevented from lowering by suppressing the decrease in the pressure of the refrigerant passing through the heat pipe during the cooling operation.

  A heater is provided as a heating unit, and a part of the heater is disposed between the heat exchanger and the fan. The heater prevents the drain water from freezing not only below the heat exchanger but also between the heat exchanger and the fan. Further, by using the heater and the heat pipe in combination, the heater can supplement the time or place where the function of the heat pipe cannot be sufficiently exhibited.

  According to the present invention, freezing of drain water from the heating unit can be prevented even if drain water flows out not only below the heat exchanger but also outside the heat exchanger. Therefore, the ice growing toward the fan can be thawed, and the fan can be protected from the ice.

Schematic configuration diagram of the refrigeration cycle of the air conditioner of the present invention The figure which shows the baseplate of the outdoor unit provided with the heat pipe Sectional view of the lower part of the cabinet where the heat pipe is installed Diagram showing heat pipe arrangement Diagram showing heat pipe that can exchange heat between pipes Diagram showing heat pipe for drain hole A figure showing a heat pipe where piping intersects Mollier diagram of the refrigeration cycle depending on the presence or absence of heat pipes Diagram showing heat pipes with different pipe diameters The figure which shows the heat pipe which has the decompression section Diagram showing heat pipe with decompression piping Diagram showing a heat pipe with pipes with different diameters The figure which shows the baseplate of the outdoor unit provided with the heater Top view of bottom plate with heat pipe and heater Cross section of bottom plate with heat pipe and heater Schematic configuration diagram of refrigeration cycle with separable heat pipe

(First embodiment)
The air conditioner of 1st Embodiment is shown in FIG. The air conditioner is configured by connecting an outdoor unit 1 and an indoor unit 2 by piping and wiring. The outdoor unit 1 includes a compressor 3, a four-way valve 4, an outdoor heat exchanger 5, an expansion valve 6, and an outdoor fan 7. The indoor unit 2 includes an indoor heat exchanger 8 and an indoor fan 9. The compressor 3, the four-way valve 4, the outdoor heat exchanger 5, the expansion valve 6, and the indoor heat exchanger 8 are connected by piping to form a refrigerant circuit. In order to connect the piping of the indoor unit 2 and the piping of the outdoor unit 1, a two-way valve 10 and a three-way valve 11 are provided in the outdoor unit. A two-way valve 10 is interposed in a pipe connecting the expansion valve 6 and the indoor heat exchanger 8, and a three-way valve 11 is interposed in a pipe connecting the four-way valve 4 and the indoor heat exchanger 8.

  The compressor 3 and the like of the outdoor unit 1 are installed in a cabinet. The cabinet is formed of a bottom plate 20, side plates surrounding the four sides, and a top plate. As shown in FIG. 2, the compressor 3, the four-way valve 4, the expansion valve 6, and piping are arrange | positioned at one corner in a cabinet. This corner is a machine room partitioned by a partition wall. The compressor 3 etc. are accommodated in the machine room.

  The outdoor heat exchanger 5 is formed in an L shape and is disposed along the side plate. A plurality of pedestals 21 are attached to the bottom plate 20, and the outdoor heat exchanger 5 is placed on the pedestal 21. A gap is formed between the outdoor heat exchanger 5 and the bottom plate 20. As shown in FIG. 3, the outdoor fan 7 is disposed near the center of the cabinet, and the outdoor heat exchanger 5 is located on the windward side of the outdoor fan 7. A mounting table 22 is formed on the bottom plate 20, a support plate is fixed to the mounting table 22, and the outdoor fan 7 is attached to the support plate 23. A plurality of drain holes 24 are formed in the bottom plate 20. The plurality of drain holes 24 are provided below the outdoor heat exchanger 5, and the drain holes 24 are arranged along the outdoor heat exchanger 5 with appropriate intervals.

  When the compressor 3 is driven, the refrigerant circulates through the refrigerant circuit. As the refrigerant circulates through the refrigerant circuit, a refrigeration cycle is formed. The control device of the air conditioner controls the refrigeration cycle and performs air conditioning operations such as cooling, heating, and dehumidification. In the cooling operation, the refrigerant circulates in the order of the compressor 3, the four-way valve 4, the outdoor heat exchanger 5, the expansion valve 6, and the indoor heat exchanger 8. In the heating operation, the refrigerant circulates in the order of the compressor 3, the four-way valve 4, the indoor heat exchanger 8, the expansion valve 6, and the outdoor heat exchanger 5.

  Here, when the heating operation is performed, if the temperature of the outdoor heat exchanger 5 becomes lower than the outside air temperature, frost forms on the surface of the outdoor heat exchanger 5. Based on the outside air temperature and the temperature of the outdoor heat exchanger, frost formation on the outdoor heat exchanger 5 is detected. When the difference between the outside air temperature and the temperature of the outdoor heat exchanger 5 becomes equal to or higher than the specified temperature, the control device determines that the outdoor heat exchanger 5 is frosted. When frost formation is detected, the control device performs a defrosting operation. For example, reverse defrosting is performed as the defrosting operation. During the heating operation, the compressor 3 is stopped and the cooling operation is started.

  When the defrosting operation is performed, the frost attached to the outdoor heat exchanger 5 is melted and dripped as drain water. The drain water is received by the bottom plate 20, and the accumulated drain water is discharged from the drain hole 24 to the outside of the cabinet. At this time, if the outside air temperature is as low as below freezing point, the drain water accumulated in the bottom plate 20 is frozen and the drainage from the drain hole 24 is prevented. In order to prevent such drain water from freezing, the outdoor unit 1 is provided with a heating unit. The heating unit is provided below the outdoor heat exchanger 5 and is arranged in a gap between the outdoor heat exchanger 5 and the bottom plate 20.

  As shown in FIG. 3, the heating unit is a heat pipe 30 using a pipe constituting a refrigerant circuit in which the refrigerant circulates. A pipe between the two-way valve 10 and the expansion valve 6 is used as the heat pipe 30, and the heat pipe 30 is disposed so as to pass below the outdoor heat exchanger 5. A part of the heat pipe 30 is disposed between the outdoor exchanger 5 and the outdoor fan 7. The heat pipe 30 is folded halfway, and the pipe connected to the indoor heat exchanger 8 side is the inlet-side pipe 31, and the pipe connected to the expansion valve 6 side is the outlet-side pipe 32.

  During the heating operation after the defrosting operation is completed, the high-temperature refrigerant flows into the pipe 31 on the inlet side. In the outlet side pipe 32, the refrigerant whose temperature has decreased due to heat dissipation flows. During the heating operation, the temperature of the pipe 31 on the inlet side is higher than the temperature of the pipe 32 on the outlet side. The pipe 31 on the inlet side passes between the outdoor exchanger 5 and the outdoor fan 7 and passes along the outer shape of the outdoor heat exchanger 5. The folded portion of the heat pipe 30 is located outside the outdoor heat exchanger 5. The pipe 32 on the outlet side is routed downward from the folded portion to the outdoor heat exchanger 5. The outlet side pipe 32 passes below the outdoor heat exchanger 5.

  The pipes 31 and 32 of the heat pipe 30 are supported by being suspended from the pedestal 21 and do not contact the bottom plate 20. The inlet-side piping 31 and the outlet-side piping 32 are arranged in parallel. As shown in FIG. 4, the pipe 32 on the outlet side passes over the drain hole 24. The pipe 31 on the inlet side passes above the drainage hole 24 or near the rim on the leeward side of the drainage hole 24. In other words, the heat pipe 30 is disposed on the leeward side of the drainage hole 24, not on the leeward side of the drainage hole 24.

  During the defrosting operation, drain water generated from the outdoor heat exchanger 5 accumulates on the bottom plate 20. At this time, the drain water dripping hits the piping 32 on the outlet side of the heat pipe 30. When the outside air temperature is low, the temperature of the heat pipe 30 becomes below the freezing point and the drain water around the piping 32 on the outlet side freezes. When the defrosting operation is completed and the heating operation is restarted, a refrigerant having a temperature higher than that below the freezing point that has passed through the indoor heat exchanger 8 flows through the heat pipe 30. Even if the drain water accumulated on the bottom plate 20 by the wind of the outdoor fan 7 flows to the outdoor fan 7 side, it is heated by the heat of the pipe 31 on the inlet side, and the drain water is prevented from freezing around the pipe 31 on the inlet side. Can be removed. It is possible to suppress the growth of ice toward the outdoor fan 7, and no ice is generated in the vicinity of the outdoor fan 7.

  Moreover, since the drain water is not directly applied to the pipe 31 on the inlet side, the heat loss of the refrigerant can be kept low. Thereby, the pipe 32 on the outlet side can maintain a sufficient amount of heat, and when there is ice below the outdoor heat exchanger 5, the ice can be thawed. When the drain water is not frozen, the drain water is frozen. You can prevent it.

(Second Embodiment)
As shown in FIG. 5, in the heating unit of the present embodiment, a part of the pipes 31 and 32 are in contact with each other so that the inlet-side pipe 31 and the outlet-side pipe 32 can directly exchange heat. Other configurations are the same as those in the first embodiment.

  A part of the inlet-side pipe 31 is formed toward the outdoor heat exchanger 5, and the inlet-side pipe 31 is fixed to the outlet-side pipe 32 so as not to be separated by welding, adhesion, or the like. Below the outdoor heat exchanger 5, a part of the inlet-side pipe 31 contacts the outlet-side pipe 32. The inlet-side pipe 31 and the outlet-side pipe 32 are in contact with one or more places. The contact point between the inlet-side pipe 31 and the outlet-side pipe 32 is preferably aligned with the position where the drain hole 24 is located. The inlet-side piping 31 is installed along the periphery of the drain hole 24. The drain water can be prevented from freezing around the drain hole 24.

  Since the two pipes 31 and 32 are in contact with each other, heat is transmitted from the high-temperature pipe to the low-temperature pipe, and the temperature of the inlet-side pipe 31 and the temperature of the outlet-side pipe 32 can be made uniform. That is, during the heating operation, heat is transferred from the inlet-side pipe 31 to the outlet-side pipe 32, the temperature of the outlet-side pipe 32 rises, and ice growth below the outdoor heat exchanger 5 can be suppressed. . During the defrosting operation, heat is transferred from the outlet side pipe 32 to the inlet side pipe 31, and a decrease in the temperature of the inlet side pipe 31 can be suppressed.

  A part of the outlet side pipe 32 may be formed toward the outdoor fan 7 side. On the outside of the outdoor heat exchanger 5, a part of the outlet side pipe 32 is in contact with the inlet side pipe 31.

(Third embodiment)
As shown in FIG. 6, in the heating unit of the present embodiment, the piping of the heat pipe 30 is provided on the windward side of the drain hole 24. A drain hole 24 is provided between the outdoor heat exchanger 5 and the outdoor fan 7 and is provided on the leeward side of the outdoor heat exchanger 5. The piping 32 on the outlet side is disposed below the outdoor heat exchanger 5 and on the bottom plate 20 on the windward side of the drain hole 24. The inlet-side piping 31 is disposed so as to pass over the drain hole 24. That is, the pipe 31 on the inlet side is provided on the windward side of the drain hole 24. Other configurations are the same as those in the first and second embodiments.

  The drain water dripped from the outdoor heat exchanger 5 is received by the bottom plate 20 on the windward side of the drain hole 24. When drain water flows toward the leeward side, it is heated by the heat of the heat pipe 30. Therefore, freezing of drain water near the drain hole 24 can be prevented. Even if the drain water is frozen, the growth of ice is suppressed near the drain hole 24, and the ice near the drain hole 24 is melted and drained from the drain hole 24. In particular, by providing the drain holes 24 around the windward side of the mounting table 22 of the outdoor fan 7, it is possible to reliably remove ice growing toward the outdoor fan 7.

(Fourth embodiment)
As shown in FIG. 7, in the heating unit of the present embodiment, the pipe 31 on the inlet side of the heat pipe 30 and the pipe 32 on the outlet side intersect each other, and the two pipes 31 and 32 for the outdoor heat exchanger 5 are intersected. The arrangement of is changed. That is, the pipe 31 on the inlet side is disposed so as to pass between the outdoor heat exchanger 5 and the outdoor fan 7 and to pass under the outdoor heat exchanger 5 from the middle. The piping 32 on the outlet side passes through the outside of the outdoor heat exchanger 5 and is arranged so as to pass under the outdoor heat exchanger 5 from the middle. Other configurations are the same as those in the first to third embodiments.

  As described above, the inlet-side pipe 31 having a higher temperature than the outlet-side pipe 32 passes below the outdoor heat exchanger 5, and the outlet-side pipe 32 passes outside the outdoor heat exchanger 5. Sufficient heat can be supplied also below the exchanger 5, and the drain water can be prevented from freezing as a whole.

  Here, the inlet-side piping 31 that passes below the outdoor heat exchanger 5 is disposed below the outdoor heat exchanger 5 so as to pass through a region where the drain holes 24 are concentrated. Thus, since heat can be locally input, the drain water around the drain hole 24 can be prevented from freezing and drainage can be performed smoothly. Thereby, drain water can be surely prevented from flowing toward the outdoor fan 7 side.

(Fifth embodiment)
In the case where the heating unit is the heat pipe 30 that uses the piping constituting the refrigerant circuit as in the above embodiment, a pressure loss of the refrigerant due to the heat pipe 30 occurs. As shown in FIG. 8, there is no refrigerant pressure loss due to the heat pipe 30 in a normal refrigeration cycle without the heat pipe 30. In this case, the cooling capacity is m × (h2−h3). m is the circulation rate (kg / s), h2 is the indoor heat exchanger outlet enthalpy (J / kg), and h3 is the indoor heat exchanger inlet enthalpy (J / kg). On the other hand, in the refrigeration cycle with the heat pipe 30, due to the pressure loss of the heat pipe 30, the cooling capacity is m ′ × (h2−h1), and h1> h2. Further, since the suction pressure is reduced, m ′ <m. Thus, the presence of the heat pipe 30 reduces the circulation amount of the refrigerant, thereby reducing the cooling capacity. Therefore, the air conditioner includes a cooling capacity decrease suppression mechanism that prevents a decrease in cooling capacity by reducing the pressure loss of the refrigerant caused by the heat pipe 30.

  As shown in FIG. 9, the cooling capacity reduction suppressing mechanism is a heat pipe 30 in which the diameter of the outlet side pipe 32 is larger than the diameter of the inlet side pipe 31. The diameter of the pipe 31 on the inlet side is the same as the diameter of other pipes constituting the refrigerant circuit. In addition, a diameter here shows an internal diameter. The inlet-side pipe 31 and the outlet-side pipe 32 pass below the outdoor heat exchanger 5, and the inlet-side pipe 31 and the outlet-side pipe 32 are connected by a taper pipe, and the large-diameter outlet-side pipe 32. Is connected to the expansion valve 6. The inlet-side piping 31 is located on the leeward side of the outlet-side piping 32. Other configurations are the same as those in the first to fourth embodiments.

  The drain water dripped by the defrosting operation is accumulated on the bottom plate 20. When the heating operation is resumed, liquid refrigerant at room temperature and high pressure flows through the heat pipe 30. Freezing of drain water is prevented by the heat of the heat pipe 30. Moreover, the growth of ice toward the outdoor fan 7 is suppressed by the heat of the inlet-side piping 31 located on the leeward side.

  During the cooling operation, the low-pressure liquid refrigerant whose temperature has decreased after passing through the expansion valve 6 passes through the heat pipe 30. The refrigerant passes through the large-diameter outlet side pipe 32 and then through the small-diameter inlet side pipe 31. The larger the pipe diameter, the lower the pressure loss of the flowing refrigerant. Since the flow rate of the refrigerant passing through the heat pipe 30 does not change, the pressure loss can be reduced. Further, since the refrigerant passes through the inlet-side pipe 31 after passing through the outlet-side pipe 32, the refrigerant is decompressed when passing through the small-diameter pipe, and the low-temperature refrigerant can be supplied to the indoor heat exchanger 8. That is, the heat of condensation can be dissipated through the pipe 32. As shown in FIG. 8, the enthalpy difference of the outdoor heat exchanger 5 increases, and the cooling capacity increases. Thereby, even if it provides the heat pipe 30, compared with the case where there is no decompression mechanism, the fall of the pressure loss by the heat pipe 30 is suppressed, and the fall of the cooling capacity can be prevented.

(Sixth embodiment)
The cooling capacity lowering suppression mechanism includes a decompression unit 35 disposed in the middle of the heat pipe 30. As shown in FIG. 10, the decompression unit 35 is provided in a pipe that passes outside the outdoor heat exchanger 5. For example, it is interposed in the folded portion of the heat pipe 30 that connects the piping 31 on the inlet side and the piping 32 on the outlet side. Other configurations are the same as those in the first to fifth embodiments.

  The decompression unit 35 is an expansion valve or a capillary tube. When performing the cooling operation, the control device adjusts the opening degree of the expansion valve 6 to control the degree of pressure reduction. That is, the opening degree of the expansion valve 6 is made larger than the opening degree set when there is no decompression unit 35. The opening degree of the expansion valve 6 is adjusted based on the temperature of the refrigerant, and the refrigerant is decompressed by the decompression unit 35. In this way, the pressure can be reduced in steps, and the low-pressure refrigerant passes through the heat pipe 30, so that the pressure loss of the refrigerant due to the heat pipe 30 can be reduced. Therefore, it is possible to suppress a decrease in cooling capacity due to the heat pipe 30. When the decompression unit 35 is an expansion valve, when performing the heating operation, the opening degree of the decompression unit 35 is maximized, and the pressure loss due to the heat pipe 30 is reduced.

  Here, when the decompression unit 35 is an expansion valve having a variable opening, the control device controls the degree of decompression by adjusting the opening of the expansion valve 6 and the decompression unit 35 when performing the cooling operation. That is, the opening degree of the expansion valve 6 is adjusted based on the temperature of the refrigerant, and the opening degree of the decompression unit 35 is also adjusted accordingly. Since the degree of decompression by the expansion valve 6 is reduced and the decompression unit 35 can further reduce the pressure, the pressure loss of the refrigerant can be further reduced. In addition, the degree of decompression can be adjusted by optimizing the cooling / heating capacity by using a variable opening degree valve such as an expansion valve as the cooling capacity reduction suppressing mechanism.

  And by providing the pressure reduction part 35 in the folding | turning part of the heat pipe 30, there is no temperature fall by the pressure reduction part 35 in the inlet side piping 31 at the time of heating operation, and the temperature of piping is maintained as it is. Thereby, the effect of freeze prevention can be exhibited reliably.

(Seventh embodiment)
As shown in FIG. 11, the cooling capacity reduction suppressing mechanism of the present embodiment is a pressure reduction that is narrower than both the pipes 31 and 32, arranged between the outlet side pipe 32 and the inlet side pipe 31 of the heat pipe 30. The pipe 36 is used. The decompression pipe 36 is made of a pipe having a smaller diameter than the diameter of the inlet-side pipe 31 and the outlet-side pipe 32, and is a short curved pipe connecting the inlet-side pipe 31 and the outlet-side pipe 32. The pipe 31 on the inlet side and the pipe 32 on the outlet side have the same diameter, or the pipe 31 has a smaller diameter than the pipe 32. Other configurations are the same as those in the first to fifth embodiments.

  The inner diameter of the decompression pipe 36 is smaller than the inner diameters of the inlet-side pipe 31 and the outlet-side pipe 32. Therefore, the decompression pipe 36 has the same function as a capital tube. When the refrigerant passes through the decompression pipe 36, the refrigerant is decompressed, and the low-pressure refrigerant passes through the inlet-side pipe 31. Thereby, the pressure loss of the refrigerant | coolant by the heat pipe 30 can be reduced, and the fall of the cooling capability can be suppressed.

  Here, the outer diameter of the decompression pipe 36 having a small inner diameter may be the same as the outer diameter of the inlet-side pipe 31 and the outlet-side pipe 32. The height of the heat pipe 30 can be made constant, and oil accumulation is less likely to occur. Thereby, the flow of a refrigerant | coolant becomes smooth and the pressure loss by disturbance of the flow of a refrigerant | coolant can be reduced.

(Eighth embodiment)
As shown in FIG. 12, the cooling capacity lowering suppression mechanism of the present embodiment has an inlet-side pipe 31 disposed below the outdoor heat exchanger 5, and an outlet-side pipe 32 on the leeward side of the inlet-side pipe 31. Therefore, the piping is arranged outside the outdoor heat exchanger 5. The diameter of the pipe 31 on the inlet side is made larger than the diameter of the pipe 32 on the outlet side. Other configurations are the same as those in the first to fifth embodiments.

  During the heating operation, the normal temperature refrigerant that is heat-exchanged by the indoor heat exchanger 8 passes through the pipe 31 on the inlet side. Since the inlet-side piping 31 is below the outdoor heat exchanger 5, the drain water dripped from the outdoor heat exchanger 5 is prevented from freezing. Moreover, by increasing the diameter of the pipe 31 on the inlet side, the surface area of the pipe increases, heat is radiated over a wide range, and the effect of preventing freezing increases. Moreover, since the piping 32 on the outlet side is located between the outdoor heat exchanger 5 and the outdoor fan 7, ice growth from the outdoor heat exchanger 5 to the outside is prevented.

  During the cooling operation, the refrigerant from the outdoor heat exchanger 5 passes through the piping 32 on the outlet side. Since the pipe 32 on the outlet side is outside the outdoor heat exchanger 5, it is not affected by the heat from the outdoor heat exchanger 5, and heat loss such as heating of the refrigerant whose temperature has decreased can be prevented. The refrigerant flows from the outlet side pipe 32 through the inlet side pipe 31 to the indoor heat exchanger 8, but the inlet side pipe 31 disposed below the outdoor heat exchanger 5 is connected to the outdoor heat exchanger 5. Even when receiving heat from the pipe, since the surface area of the pipe is large, the balance between heat absorption and exhaust heat is maintained, and the temperature rise of the refrigerant is prevented. By adopting the above-described piping arrangement, it is possible to prevent freezing while suppressing a decrease in cooling capacity.

(Ninth embodiment)
A heat pipe 30 is provided to prevent freezing of drain water accumulated in the outdoor unit 1. The heat pipe 30 uses a heat source for refrigeration cycle operation. Therefore, since a new heat source is not added, an energy saving effect can be obtained. However, when the inlet temperature of the expansion valve 6 is low as at the start of the refrigeration cycle operation, the heat pipe 30 cannot secure a sufficient amount of heat and cannot prevent the drain water from freezing, or accumulates on the bottom plate 20 of the cabinet. There is a possibility that the ice produced by freezing the drain water that has been frozen cannot be thawed.

  Therefore, in the present embodiment, it is possible to prevent the drain water from freezing whenever the refrigeration cycle operation is performed. That is, not only the heat pipe 30 but also the heater 40 is provided as a heating unit. The control device controls the heater 40 so that the heater 40 operates at a time when the function of the heat pipe 30 is insufficient in order to complement the function of preventing the freeze by the heat pipe 30. When the function of the heat pipe 30 is sufficiently exhibited, the control device stops the operation of the heater 40.

  As shown in FIGS. 13 to 15, the pipe 31 on the inlet side and the pipe 32 on the outlet side of the heat pipe 30 are arranged below the outdoor heat exchanger 5. The inlet-side piping 31 is located on the leeward side of the outlet-side piping 32. The heater 40 is disposed below the outdoor heat exchanger 5, and a part of the heater 40 is disposed between the outdoor heat exchanger 5 and the outdoor fan 7. The heater 40 is disposed so as to surround the outside of the heat pipe 30. The heater 40 is located on the leeward side of the outlet side pipe 32 below the outdoor heat exchanger 5, and is located on the leeward side of the inlet side pipe 31 and outside the outdoor heat exchanger 5. .

  The heater 40 is disposed below the heat pipe 30 and is provided on the bottom plate 20 of the cabinet. A hook 41 is attached to the bottom plate 20, a heater 40 is fitted into the hook 41, and the heater 40 is fixed to the bottom plate 20. The heat pipe 30 and the heater 40 pass over the drain hole 24. Other configurations are the same as those in the first to eighth embodiments.

  The heater 40 is driven when the heat pipe 30 does not function sufficiently, and is not driven when the heat pipe 30 functions sufficiently. That is, the function of the heat pipe 30 is insufficient when the temperature of the refrigerant is low, such as when starting the refrigeration cycle operation. At this time, the heater 40 operates to prevent the drain water from freezing, and when the drain water is frozen, the ice is thawed. When the refrigeration cycle is stabilized, the temperature of the refrigerant is increased, and the function of the heat pipe 30 is sufficiently exhibited. At this time, the heater 40 does not operate.

  The control device determines whether the operation of the heater 40 is necessary based on the ambient temperature of the heat pipe 30 and controls on / off of the heater 40. The control device turns on the heater 40 when the ambient temperature is equal to or lower than the specified temperature, and turns off the heater 40 when the ambient temperature exceeds the specified temperature. The ambient temperature of the heat pipe 30 is, for example, the inlet temperature of the expansion valve 6. The specified temperature is set to a temperature slightly higher than 0 ° C., for example.

  When the heating operation is started, the refrigerant heat-exchanged in the indoor heat exchanger 8 passes through the heat pipe 30 and flows into the expansion valve 6. At the start of the heating operation, the control device detects the inlet temperature of the expansion valve 6 and determines whether or not the operation of the heater 40 is necessary. When the inlet temperature of the expansion valve 6 is equal to or lower than the specified temperature, the control device determines that the function of the heat pipe 30 is insufficient and turns on the heater 40. The heater 40 is energized and generates heat.

  At the beginning of the heating operation, the refrigerant temperature is low. At this time, since the heater 40 operates, even if the drain water accumulated in the bottom plate 20 is frozen, the heater 40 defrosts the ice. In particular, when the periphery of the drain hole 24 is frozen, the surrounding ice is melted and drained from the drain hole 24. When drain water is generated by the defrosting operation, the drain water can be discharged smoothly. In this way, the drain water is prevented from freezing due to the heat of the heater 40. Further, when there is ice grown from the lower side of the outdoor heat exchanger 5 toward the outdoor fan 7, the ice can be melted by the heater 40.

  When the refrigeration cycle is stabilized, the temperature of the refrigerant rises and the inlet temperature of the expansion valve 6 also rises. When the control device detects that the inlet temperature of the expansion valve 6 exceeds the specified temperature, the control device determines that the heat pipe 30 functions sufficiently and turns off the heater 40. Although the heater 40 stops, the heat of the heat pipe 30 prevents the drain water from freezing.

  Thus, the heater 40 operates only when the function of the heat pipe 30 is insufficient, and complements the heat pipe 30. When only the heat pipe 30 is sufficient, the heater 40 does not operate, so that power consumption can be suppressed.

  The ambient temperature of the heat pipe 30 for determining the operation of the heater 40 may be the outside air temperature. The control device operates the heater 40 for a predetermined time when the outside air temperature is 0 ° C. or lower, and does not operate the heater 40 when the outside air temperature is higher than 0 ° C. When the defrosting operation is completed, the heating operation is started. At this time, when the temperature of the refrigerant is higher than 0 ° C., the inlet temperature of the expansion valve 6 becomes higher than the specified temperature. Here, when the outside air temperature is 0 ° C. or less, the heater 40 operates even if the temperature of the refrigerant is high. Since not only the heat pipe 30 but also the heater 40 works, the drain water dripped onto the bottom plate 20 is discharged from the drain hole 24 without freezing. When the drain water accumulated in the bottom plate 20 is discharged, the problem of freezing of the drain water is solved, so that the heater 40 is unnecessary. When a certain period of time has elapsed from the start of the heating operation, the heater 40 is turned off, and unnecessary power consumption is eliminated.

(10th Embodiment)
When the heating operation is started, the temperature of the refrigerant gradually increases. Along with this, the function of the heat pipe 30 is exhibited. Therefore, the operation of the heater 40 is controlled according to the temperature of the refrigerant. The control device decreases the output of the heater 40 as the temperature of the refrigerant increases. Other configurations are the same as those of the ninth embodiment.

  At the start of the heating operation, the control device turns on the heater 40 when the inlet temperature of the expansion valve 6 is equal to or lower than the specified temperature. The heater 40 is energized and generates heat. The temperature of the refrigerant gradually rises and the inlet temperature of the expansion valve 6 rises. The control device monitors the inlet temperature of the expansion valve 6 and decreases the energization amount to the heater 40 as the inlet temperature rises. As the temperature of the refrigerant increases, the output of the heater 40 decreases. When the inlet temperature of the expansion valve 6 becomes higher than the specified temperature, the control device turns off the heater 40. Instead of the inlet temperature of the expansion valve 6, the temperature of the outdoor heat exchanger 5 may be monitored, and the heater 40 may be controlled according to this temperature.

  Even if the output of the heater 40 decreases and the amount of heat generation decreases, the heat from the heat pipe 30 increases and the effect of preventing drain water from freezing is exhibited. Thus, if the temperature of a refrigerant | coolant rises early, the operation time of the heater 40 will become short. Therefore, since the amount of current supplied to the heater 40 is reduced, power consumption can be reduced, and energy saving can be achieved.

(Eleventh embodiment)
Above the heater 40, the heat pipe 30 passes and the outdoor heat exchanger 5 is located. The heat pipe 30 and the outdoor heat exchanger 5 can be warmed by the heat of the heater 40. Therefore, when the heating operation is performed, the heater 40 is operated regardless of the ambient temperature of the heat pipe 30 in order to quickly raise the temperature of the refrigerant. Other configurations are the same as those of the ninth and tenth embodiments.

  When the heating operation is started, the control device turns on the heater 40. The refrigerant passing through the heat pipe 30 is warmed, and the outdoor heat exchanger 5 is also warmed. Thereby, since the warmed refrigerant | coolant is sent into the compressor 3, it becomes unnecessary to drive | operate the compressor 3 at high rotation, an operating efficiency improves and it can reduce power consumption. Moreover, the drain water can be prevented from freezing by the heat of the heater 40.

  Here, it is preferable to operate the heater 40 for a predetermined time at the start of the heating operation. When starting the heating operation, the control device turns on the heater 40 for a predetermined time. When a certain time elapses, the heater 40 is stopped. Thereby, the start-up of heating operation can be made early and warm air can be blown out quickly.

  When the heating operation is reserved, the control device operates the heater 40 before the reserved start time. When a predetermined time before the reserved start time, the heater 40 is turned on. The heater 40 operates at least for a predetermined time. Thereby, when drain water is frozen, ice can be removed before the start of operation. Moreover, the refrigerant sucked into the compressor 3 can be warmed in advance, so that the heating operation can be started more quickly.

  Further, the heater 40 may be operated according to the outside air temperature. The control device turns on the heater 40 when the outside air temperature is equal to or lower than the refrigerant temperature, and turns off the heater 40 when the outside air temperature is higher than the refrigerant temperature. Thereby, when the heat exchange efficiency is poor, the heater 40 operates to warm the refrigerant.

(Twelfth embodiment)
As a cooling capacity reduction suppressing mechanism, the heat pipe 30 is separated from the refrigerant circuit when the heat pipe 30 is unnecessary, and the heat pipe 30 is incorporated into the refrigerant circuit when necessary. As shown in FIG. 16, the heat pipe 30 is provided so as to branch from the refrigerant circuit, the inlet side pipe 31 is connected to the refrigerant circuit pipe via the first flow path switching valve 45, and the outlet side pipe 32. Is connected to the piping of the refrigerant circuit via the second flow path switching valve 46. The control device operates the flow path switching valves 45 and 46 in accordance with the refrigeration cycle operation. Other configurations are the same as those of the ninth to eleventh embodiments.

  The first flow path switching valve 45 communicates the refrigerant circuit and the inlet side pipe 31 or disconnects the inlet side pipe 31 from the refrigerant circuit to switch the refrigerant flow path. The second flow path switching valve 46 communicates the refrigerant circuit with the outlet side pipe 32 or disconnects the outlet side pipe 32 from the refrigerant circuit to switch the refrigerant flow path. During the heating operation, the inlet side pipe 31 and the outlet side pipe 32 communicate with the refrigerant circuit, and the heat pipe 30 is incorporated into the refrigerant circuit. During the cooling operation, the inlet side pipe 31 and the outlet side pipe 32 are disconnected from the refrigerant circuit, and the heat pipe 30 is separated from the refrigerant circuit. Thus, since the heat pipe 30 is not required during the cooling operation, the heat pipe 30 is separated from the refrigerant circuit. The pressure loss due to the heat pipe 30 is eliminated, and the problem of a decrease in cooling capacity does not occur. Moreover, since the heat pipe 30 functions by being incorporated in the refrigerant circuit during the heating operation, the drain water can be prevented from freezing.

  As described above, the air conditioner of the present invention includes a cabinet in which a heat exchanger and a fan, for example, the outdoor heat exchanger 5 and the outdoor fan 7 are installed, and the heat exchanger 5 is disposed on the windward side of the fan 7. And the heating part which prevents the freezing of the drain water dripped from the heat exchanger 5 is provided under the heat exchanger 5, and the freezing of the drain water is prevented between the heat exchanger 5 and the fan 7. Therefore, a part of the heating unit is disposed between the heat exchanger 5 and the fan 7. As a result, the drain water can be prevented from freezing not only below the heat exchanger 5 but also between the heat exchanger 5 and the fan 7, and the adverse effect of the ice on the fan 7 can be eliminated.

  The drainage hole 24 formed below the heat exchanger 5 is located between the heat exchanger 5 and the fan 7, and the heating unit is disposed on the windward side of the drainage hole 24. Thereby, the ice growing toward the fan 7 can be melted and drained from the drain hole 24.

  The heating unit is a heat pipe 30 using a pipe through which a refrigerant circulates, and a pipe 32 on the outlet side of the heat pipe 30 is arranged below the heat exchanger 5, and the pipe 31 on the inlet side of the heat pipe 30 has a high temperature. The refrigerant flows, the low-temperature refrigerant flows out from the pipe 32 on the outlet side of the heat pipe 30, and the heat of the pipe 31 on the inlet side of the heat pipe 30 is transferred to the lower side of the heat exchanger 5. A part of the pipe 31 on the side passes under the heat exchanger 5. Thereby, the temperature of the pipe 32 on the outlet side can be increased, and the freezing of drain water below the heat exchanger 5 can be reliably prevented.

  When the heating pipe is a heat pipe 30 using a refrigerant circulation pipe, the inlet pipe 31 of the heat pipe 30 passes between the heat exchanger 5 and the fan 7 and the outlet pipe 32 of the heat pipe 30. Passes below the heat exchanger 5. That is, a part of the heat pipe 30 is disposed between the heat exchanger 5 and the fan 7. A pipe 31 on the inlet side of the heat pipe 30 is arranged on the windward side of the drain hole 24. The piping 31 on the high temperature inlet side can prevent ice from growing outside the heat exchanger 5. Moreover, freezing of drain water around the drain hole 24 can be prevented.

  A pipe 31 on the inlet side of the heat pipe 30 is connected to a pipe from the indoor heat exchanger 8, and a pipe 32 on the outlet side is connected to a throttle mechanism such as the expansion valve 6. When the heating operation is performed, a refrigerant having a high temperature can be flowed through the pipe 31 on the inlet side.

  The pipe 31 on the inlet side and the pipe 32 on the outlet side of the heat pipe 30 are in contact with each other. Thereby, the heat of the high temperature side pipe can be transferred to the low temperature side pipe, and the effect of preventing the drain water from freezing below the heat exchanger 5 can be enhanced. In addition, the pipe 31 on the inlet side and the pipe 32 on the outlet side of the heat pipe 30 intersect in the middle, the pipe 31 on the inlet side passes under the heat exchanger 5, and the pipe 32 on the outlet side of the heat exchanger 5. Pass outside. Also by this, since the high-temperature side pipe passes below the heat exchanger 5, the effect of preventing the freezing of the drain water below the heat exchanger 5 can be enhanced.

  The heating unit is a heat pipe 30 that uses a pipe through which the refrigerant circulates, and includes a cooling capacity reduction suppression mechanism that prevents a reduction in cooling capacity due to a pressure loss of the refrigerant flowing through the heat pipe 30. Thereby, when the cooling operation is performed, a decrease in the pressure of the refrigerant passing through the heat pipe 30 can be suppressed, and a decrease in the cooling capacity can be prevented.

  As a cooling capacity reduction suppressing mechanism, the diameter of the outlet pipe 32 of the heat pipe 30 is made larger than the diameter of the inlet pipe 31, and the decompression unit 35 is arranged in the middle of the heat pipe 30. For example, a decompression pipe 36 thinner than both pipes may be disposed between the outlet-side pipe 32 and the inlet-side pipe 31. Since the pressure of the refrigerant passing through the outlet side pipe 32 becomes low, the pressure loss of the refrigerant can be reduced. The decompression pipe 36 is a pipe having the same outer diameter as the pipe of the heat pipe 30 and a smaller inner diameter than the pipe of the heat pipe 30. By using such a decompression pipe 36, the heat pipe 30 can be disposed horizontally.

  The cooling capacity lowering suppression mechanism is configured such that the inlet side pipe 31 of the heat pipe 30 is arranged below the heat exchanger 5, and the outlet side pipe 32 is on the leeward side of the inlet side pipe 31. Arrange on the outside. The diameter of the pipe 31 on the inlet side is made larger than the diameter of the pipe 32 on the outlet side. Thus, since a part of heat pipe 30 exists in the outer side of the heat exchanger 5, it does not receive to the influence of the heat of the heat exchanger 5 at the time of air_conditionaing | cooling operation. Therefore, the heat loss of the refrigerant can be reduced, and a decrease in cooling capacity can be prevented. Moreover, at the time of heating operation, freezing of drain water can be prevented by the heat of the piping under the heat exchanger 5.

  A heater 40 is provided as a heating unit, and a part of the heater 40 is disposed between the heat exchanger 5 and the fan 7. The growth of ice toward the fan 7 can be suppressed by the heat of the heater 40. Moreover, when the heater 40 and the heat pipe 30 are used in combination, the heater 40 can be supplemented when the function of the heat pipe 30 is insufficient.

  Regarding the operation of the heater 40, the control device operates the heater 40 when starting the heating operation. Thereby, the ice produced | generated during the operation stop can be thawed and it can drive | operate without trouble. The control device operates the heater 40 when the ambient temperature of the heat pipe 30 is low. The heater 40 can be efficiently controlled based on the ambient temperature such as the temperature of the refrigerant and the outside air temperature, and power consumption can be reduced. The control device controls the operation of the heater 40 according to the temperature of the refrigerant. When the temperature of the refrigerant rises, the amount of electricity supplied to the heater 40 decreases, so that power consumption can be reduced.

  In addition, this invention is not limited to the said embodiment, Of course, many corrections and changes can be added to the said embodiment within the scope of the present invention. The air conditioner is not limited to a separate type, and may be an integrated type. In this case, a heating part is provided with respect to the heat exchanger which functions as an evaporator at the time of heating operation. Moreover, you may comprise a heating part only with a heater.

  In each embodiment, the heat pipe 30 is provided so as to be in contact with the drain water accumulated on the bottom plate 20 of the cabinet. The pipe 31 on the inlet side and the pipe 32 on the outlet side of the heat pipe 30 are rubber pipes or resin pipes, and the pipe of the heat pipe 30 is connected to the metal pipe of the refrigerant circuit via a flexible pipe. Further, a flexible pipe is interposed between the inlet side pipe 31 and the outlet side pipe 32 at the folded portion of the heat pipe 30. The flexible pipe is supported by the bottom plate 20, and both ends of the inlet side pipe 31 and the outlet side pipe 32 are supported so as to be movable in the vertical direction.

  Thereby, the piping of the heat pipe 30 can move in the vertical direction with respect to the piping of the fixed refrigerant circuit. When the liquid refrigerant flows into the heat pipe 30 during the heating operation, the pipe of the heat pipe 30 is lowered to the vicinity of the bottom plate 20 by its own weight and comes into contact with drain water accumulated in the bottom plate 20. The heat of the heat pipe 30 directly acts on the drain water, so that the drain water can be reliably prevented from freezing and the ice can be defrosted. During the cooling operation, the gas-liquid two-phase refrigerant flows into the heat pipe 30. The piping of the heat pipe 30 is not lowered as compared with the heating operation.

  In the ninth to twelfth embodiments, the pipe 31 on the inlet side of the heat pipe 30 may be disposed outside the outdoor heat exchanger 5. In addition, the heater 40 may be located either on the windward side or the leeward side of the pipe 31 on the inlet side.

  A plurality of drain holes 24 are provided in the bottom plate 20. A heater 40 is provided for each drain hole 24. The plurality of heaters 40 are connected in parallel, and each heater 40 is formed so as to surround the periphery of the drain hole 24 or is formed so as to straddle the drain hole 24.

DESCRIPTION OF SYMBOLS 1 Outdoor unit 2 Indoor unit 3 Compressor 4 Four-way valve 5 Outdoor heat exchanger 6 Expansion valve 7 Outdoor fan 8 Indoor heat exchanger 9 Indoor fan 20 Bottom plate 24 Drain hole 30 Heat pipe 31 Inlet side piping 32 Outlet side piping 35 Pressure reducing part 36 Pressure reducing pipe 40 Heater

Claims (5)

The cabinet, the outdoor heat exchanger and the fan are furnished, the outdoor heat exchanger is an air conditioner that is disposed on the windward side of the fan, the drainage holes outdoor heat formed in the bottom plate below the outdoor heat exchanger An indoor heat exchanger is positioned between the heat exchanger and the fan to prevent freezing of drain water dripping from the outdoor heat exchanger and flowing to the fan side between the outdoor heat exchanger and the fan. An air conditioner characterized in that a heat pipe using a pipe connecting the expansion valve is provided, and a pipe on the inlet side of the heat pipe through which a high-temperature refrigerant flows is arranged between the outdoor heat exchanger and the fan . 2. The pipes of the heat pipe are suspended and supported by a pedestal on which the outdoor heat exchanger is placed so that the drain water does not hit the pipe on the inlet side of the heat pipe . Air conditioner. An air conditioner in which an outdoor heat exchanger and a fan are installed in a cabinet, and the outdoor heat exchanger is arranged on the windward side of the fan, and is dropped from the outdoor heat exchanger between the outdoor heat exchanger and the fan. In order to prevent the drain water flowing to the fan side from freezing, a heat pipe using a pipe through which the refrigerant circulates is provided, and the pipe on the outlet side of the heat pipe is arranged below the outdoor heat exchanger, A high-temperature refrigerant flows through the pipe on the inlet side of the pipe, a low-temperature refrigerant flows out from the pipe on the outlet side of the heat pipe, and the heat of the pipe on the inlet side of the heat pipe is transferred below the outdoor heat exchanger, An air conditioner characterized in that a part of the pipe on the inlet side of the heat pipe passes below the outdoor heat exchanger. The air conditioner according to claim 1, characterized in that with a cooling capacity suppressing reduction mechanism to prevent a decrease in cooling capacity due to the pressure loss of the refrigerant flowing in the heat Topaipu. The air conditioner according to any one of claims 1 to 4, wherein a heater used in combination with the heat pipe is provided, and a part of the heater is disposed between the outdoor heat exchanger and the fan.

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