JP2019158311A - Air conditioner and control method of the same - Google Patents

Abstract

To provide an air conditioner capable of efficiently performing cooling and heating of the indoor air, and to provide a control method of the same.SOLUTION: A reheating heat exchanger 7 is installed on the downstream side of an indoor heat exchanger 6 in a direction in which an inside air passing an indoor unit 3 flows, a refrigerant to be compressed in a compressor 9 at the time of reheat dehumidifying operation is supplied to the reheating heat exchanger 7, the refrigerant in which the heat is deprived of by the inside air in the reheating heat exchanger 7 is supplied to an outdoor heat exchanger 4, and the refrigerant in which the heat is deprived of by the outdoor air in the outdoor heat exchanger 4 is decompressed in an expansion valve 14 and then supplied to the indoor heat exchanger 6.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a heat pump type air conditioner and a control method thereof, and more particularly to an air conditioner capable of efficiently cooling and heating indoor air and a control method thereof.

  Various heat pump type air conditioners have been proposed (see, for example, Patent Document 1). Patent Document 1 proposes an air conditioner including two heat exchangers installed in an indoor unit and an expansion valve disposed between the heat exchangers. During the reheat dehumidifying operation, the air conditioner supplies the refrigerant having a high temperature and high pressure with the compressor to the heat exchanger of the outdoor unit and cools it with outdoor air (hereinafter sometimes referred to as outdoor air). The indoor air (hereinafter sometimes referred to as “inside air”) was heated by supplying it to a heat exchanger for reheating installed in the room. Thereafter, the refrigerant discharged from the heat exchanger for reheating is decompressed by the expansion valve and then supplied to the heat exchanger installed in the indoor unit to cool the inside air.

  The air conditioner described in Document 1 has a problem that the inside air cannot be efficiently heated because the refrigerant supplied to the heat exchanger for reheating is cooled by the outside air before heating the inside air. Moreover, if the cooling of the refrigerant by the outside air is suppressed in order to efficiently heat the inside air, the temperature of the refrigerant circulating in the air conditioner increases as a whole and the condensation pressure rises. When the condensing pressure rises, the shaft power required by the compressor increases, so there is a problem that the energy efficiency of the air conditioner decreases. As the condensing pressure of the refrigerant increases, the shaft power of the compressor increases, so that the throttle expansion process in the air conditioner is performed from a larger enthalpy. As a result, the evaporation process is shortened, so that there is a problem that cooling when the inside air is cooled by the heat exchanger of the indoor unit cannot be efficiently performed.

  That is, the air conditioner described in Document 1 has a problem that the efficiency of either heating or cooling of the inside air decreases during the reheat dehumidification operation, and the efficiency of the air conditioner is not good.

Japanese Unexamined Patent Publication No. 2011-112327

  The present invention has been made in view of the above problems, and an object thereof is to provide an air conditioner capable of efficiently cooling and heating indoor air and a control method thereof.

  An air conditioner that achieves the above object includes a compressor that compresses the refrigerant, an expansion valve that decompresses the refrigerant, an outdoor heat exchanger that is installed in the outdoor unit and performs heat exchange between the refrigerant and the outside air, In a heat pump type air conditioner that is installed in an indoor unit and includes an indoor heat exchanger that exchanges heat between the refrigerant and the inside air and a heat exchanger for reheating, in the direction in which the inside air that passes through the indoor unit flows A first line for supplying the refrigerant compressed by the compressor to the reheat heat exchanger, the reheat heat exchanger having a configuration installed on the downstream side of the indoor heat exchanger; The second line for supplying the refrigerant discharged from the reheat heat exchanger to the outdoor heat exchanger, the outdoor heat exchanger and the indoor heat exchanger are communicated with each other, and the expansion valve is provided in the middle portion. The third line to be installed and the room The refrigerant discharged from the exchanger, characterized in that it comprises a fourth line supplied to the compressor.

  The control method of the air conditioner that achieves the above object includes a compressor that compresses the refrigerant, an expansion valve that decompresses the refrigerant, and an outdoor heat exchange that is installed in the outdoor unit and performs heat exchange between the refrigerant and the outside air And a heat pump type air conditioner control method comprising an indoor unit and an indoor heat exchanger that is installed in the indoor unit and performs heat exchange between the refrigerant and the inside air, and a heat exchanger for reheating. The reheat heat exchanger is installed on the downstream side of the indoor heat exchanger in the direction in which the inside air flows, and the refrigerant compressed by the compressor is reheated during the reheat dehumidifying operation. Supply to the outdoor heat exchanger, the refrigerant whose heat has been taken away by the reheat heat exchanger to the outdoor heat exchanger, and the refrigerant whose heat has been taken away by the outdoor air by the outdoor heat exchanger. The pressure is reduced by a valve and then supplied to the indoor heat exchanger To.

  According to the present invention, since the refrigerant (superheated steam) that has been compressed by the compressor and is overheated can be supplied to the reheat heat exchanger, the inside air can be efficiently heated. Moreover, since the refrigerant | coolant (saturated liquid) cooled with the outdoor heat exchanger can be supplied to an indoor heat exchanger after decompressing with an expansion valve, internal air can be cooled efficiently. Since both heating and cooling of the inside air can be efficiently performed in the indoor unit during the reheat dehumidifying operation, it is advantageous for improving the efficiency of the air conditioner.

It is explanatory drawing which illustrates the air conditioner of this invention. It is explanatory drawing which illustrates the modification of the air conditioner illustrated in FIG. It is explanatory drawing which illustrates the state of the air_conditionaing | cooling operation of the air conditioner illustrated in FIG. It is explanatory drawing which illustrates the air conditioner of another embodiment of this invention. It is explanatory drawing which illustrates the state of the reheat dehumidification driving | running of the air conditioner illustrated in FIG. It is explanatory drawing which illustrates the state of the heating operation of the air conditioner illustrated in FIG. It is explanatory drawing which illustrates the state of the cooling operation of the air conditioner illustrated in FIG.

  Hereinafter, an air conditioner and a control method thereof according to the present invention will be described based on the embodiments shown in the drawings.

  As illustrated in FIG. 1, the heat pump type air conditioner 1 of the present invention includes an outdoor unit 2 disposed outside and an indoor unit 3 disposed indoors. The outdoor unit 2 is provided with an outdoor heat exchanger 4 for exchanging heat between outside air (outdoor air) and a refrigerant, and an outdoor fan 5 for supplying outside air to the outdoor heat exchanger 4. Yes. In FIG. 1, the direction in which the outside air flows is indicated by white arrows for the sake of explanation.

  To supply indoor air to the indoor heat exchanger 6 and the reheat heat exchanger 7 that exchange heat between the indoor air (indoor air) and the refrigerant, the indoor heat exchanger 6 and the like to the indoor unit 3 Indoor air blower 8 is installed. In FIG. 1, the direction in which the inside air flows is indicated by white arrows for the sake of explanation.

  A reheat heat exchanger 7 is installed on the downstream side of the indoor heat exchanger 6 in the direction in which the inside air passing through the interior of the indoor unit 3 flows. That is, the inside air guided to the inside of the indoor unit 3 contacts the indoor heat exchanger 6 and then contacts the reheat heat exchanger 7.

  The air conditioner 1 includes a compressor 9 that compresses refrigerant, a first line 10 that communicates the compressor 9 and the reheat heat exchanger 7, a reheat heat exchanger 7, and an outdoor heat exchanger 4. A second line 11 that communicates with each other, a third line 12 that communicates with the outdoor heat exchanger 4 and the indoor heat exchanger 6, and a fourth line 13 that communicates with the indoor heat exchanger 6 and the compressor 9. ing. An expansion valve 14 is installed in the middle of the third line 12. The 1st line 10, the 2nd line 11, the 3rd line 12, and the 4th line 13 represent the flow path of the refrigerant | coolant comprised with a pipe.

  The air conditioner 1 of the embodiment illustrated in FIG. 1 can perform a reheat dehumidification operation. In FIG. 1, the direction in which the refrigerant flows is indicated by arrows for the sake of explanation.

  When the air conditioner 1 performs the reheat dehumidification operation, the refrigerant is first compressed by the compressor 9 to become high-temperature and high-pressure superheated steam and is supplied to the reheat heat exchanger 7 via the first line 10. The reheat heat exchanger 7 heats the inside air using the heat of the refrigerant. The refrigerant deprived of heat by the reheat heat exchanger 7 is supplied to the outdoor heat exchanger 4 via the second line 11. In the outdoor heat exchanger 4, the refrigerant is cooled by outside air. In the process of taking heat away from the heat exchanger 7 for reheating and the outdoor heat exchanger 4, the refrigerant changes from superheated steam to saturated steam and further loses heat to liquefy to become saturated liquid. The refrigerant that is deprived of heat in the outdoor heat exchanger 4 and becomes a saturated liquid is supplied to the indoor heat exchanger 6 via the third line 12. The refrigerant is depressurized by the expansion valve 14 in the middle of the third line 12 to become low-temperature and low-pressure wet steam. The indoor heat exchanger 6 dehumidifies by cooling the inside air using this refrigerant and condensing the moisture in the inside air. The refrigerant that has been evaporated by absorbing heat from the inside air in the indoor heat exchanger 6 is supplied to the compressor 9 via the fourth line 13. As described above, the refrigerant circulates inside the air conditioner 1.

  The inside air introduced into the indoor unit 3 is first cooled and dehumidified by the indoor heat exchanger 6, heated by the reheat heat exchanger 7, and discharged from the indoor unit 3. Since the cooled inside air is heated and then discharged, the air conditioner 1 can perform dehumidification while maintaining the room temperature.

  According to the present invention, the compressor 9 and the reheat heat exchanger 7 are directly communicated by the first line 10. In addition, no device or the like that takes heat away from the refrigerant is disposed in the middle of the first line 10. The superheated refrigerant that has been compressed by the compressor 9 to a high temperature is immediately supplied to the heat exchanger 7 for reheating. The refrigerant (superheated steam) supplied to the reheat heat exchanger 7 is in a state where the temperature is the highest while circulating inside the air conditioner 1. Therefore, it is advantageous to efficiently heat the inside air with the heat exchanger 7 for reheating.

  Further, the refrigerant that has been cooled by the reheat heat exchanger 7 and the outdoor heat exchanger 4 and then reduced in pressure to become low-temperature and low-pressure wet steam is supplied to the indoor heat exchanger 6. The refrigerant supplied to the indoor heat exchanger 6 is in the lowest temperature while circulating inside the air conditioner 1. Therefore, it is advantageous to efficiently cool the inside air with the indoor heat exchanger 6. Since both heating and cooling of the inside air can be efficiently performed during the reheat dehumidifying operation, it is advantageous for improving the efficiency of the air conditioner 1.

  The refrigerant is sufficiently cooled by both the reheat heat exchanger 7 and the outdoor heat exchanger 4. The temperature of the refrigerant circulating in the air conditioner 1 is lowered as a whole, and the condensation pressure of the refrigerant is lowered. Since the shaft power required for compressing the refrigerant by the compressor 9 is reduced, it is advantageous for improving the energy efficiency of the air conditioner 1. Further, since the shaft power of the compressor 9 decreases as the condensing pressure of the refrigerant decreases, the throttle expansion process in the air conditioner 1 can be performed from a smaller enthalpy. As a result, the evaporation process becomes longer and the cooling capacity can be improved.

  In addition to the configuration illustrated in FIG. 1, the air conditioner 1 illustrated in FIG. 2 further includes a fifth line 15 that directly connects the reheat heat exchanger 7 and the indoor heat exchanger 6, and an outdoor heat exchanger. 4 and a sixth line 16 that communicates with the compressor 9. Thereby, the air conditioner 1 of this embodiment can perform heating operation and cooling operation in addition to the reheat dehumidification operation. In FIG. 2, the direction in which the refrigerant flows during the heating operation is indicated by an arrow for explanation. In FIG. 2, the flow path through which the refrigerant does not pass is indicated by a broken line for the sake of explanation.

When the air conditioner 1 performs the heating operation, first, the refrigerant is compressed by the compressor 9 to become high temperature and high pressure, and is supplied to the reheat heat exchanger 7 via the first line 10. The reheat heat exchanger 7 heats the inside air using the heat of the refrigerant. The refrigerant deprived of heat by the reheat heat exchanger 7 is supplied to the indoor heat exchanger 6 via the fifth line 15.

  A relatively high-temperature refrigerant is supplied to the reheat heat exchanger 7, and a refrigerant having a temperature lower than that at this time is supplied to the indoor heat exchanger 6. On the other hand, in the indoor unit 3, the indoor air having a relatively low temperature is heated by the indoor heat exchanger 6, and the internal air having a relatively high temperature is heated by the heat exchanger 7 for reheating. That is, the direction in which the refrigerant flows and the direction in which the inside air flows are opposite to each other.

  In the indoor unit 3, heat exchange is performed stepwise between the indoor heat exchanger 6 and the reheat heat exchanger 7 in a state where the temperature difference between the refrigerant and the inside air is relatively small. The refrigerant and the inside air constitute a so-called counterflow heat exchange system. Heating of the inside air by the air conditioner 1 can be performed very efficiently, which is advantageous for improving the efficiency of the air conditioner 1.

  Since no expansion valve or refrigerant branch is installed in the middle of the fifth line 15, the entire amount of refrigerant discharged from the reheat heat exchanger 7 is supplied to the indoor heat exchanger 6 without being reduced in pressure. Is done. Since the fifth line 15 does not generate a state in which the refrigerant is evaporated and energy is consumed in accordance with the reduced pressure, the indoor heat exchanger 6 can efficiently heat the inside air.

  The refrigerant that is deprived of heat in the indoor heat exchanger 6 and becomes a saturated liquid is supplied to the outdoor heat exchanger 4 via the third line 12. The refrigerant is depressurized by the expansion valve 14 in the middle of the third line 12 to become low-temperature and low-pressure wet steam. In the outdoor heat exchanger 4, the refrigerant is heated by the outside air. The refrigerant that is vaporized by being supplied with heat by the outdoor heat exchanger 4 is supplied to the compressor 9. When the air conditioner 1 performs the heating operation, the refrigerant is configured to circulate inside the air conditioner 1 as described above.

  FIG. 3 illustrates a state when the air conditioner 1 illustrated in FIG. 2 performs the cooling operation. In FIG. 3, the direction in which the refrigerant flows is indicated by arrows for the sake of explanation. In FIG. 3, the flow path through which the refrigerant does not pass is indicated by a broken line for the sake of explanation.

  As illustrated in FIG. 3, when the air conditioner 1 performs a cooling operation, the refrigerant is first compressed by the compressor 9 to become high-temperature and high-pressure superheated steam, and is supplied to the outdoor heat exchanger 4 via the sixth line 16. Is done. The refrigerant that is deprived of heat in the outdoor heat exchanger 4 and becomes a saturated liquid is supplied to the indoor heat exchanger 6 via the third line 12. The refrigerant that is decompressed by the expansion valve 14 in the middle of the third line 12 to become low-temperature and low-pressure wet steam is supplied to the indoor heat exchanger 6. The indoor heat exchanger 6 cools the inside air by using this refrigerant and performs cooling. The refrigerant that has absorbed heat from the inside air in the indoor heat exchanger 6 is supplied to the compressor 9 via the fourth line 13. When the air conditioner 1 performs the cooling operation, the refrigerant is configured to circulate inside the air conditioner 1 as described above.

  An open / close valve, a three-way valve, a four-way valve, or the like can be appropriately installed in the flow path of the first line 10 or the like. The reflow dehumidifying operation state, the heating operation state, and the cooling operation state of the air conditioner 1 can be switched by switching the flow path through which the refrigerant flows by an open / close valve or the like installed in the middle of the refrigerant flow path. .

When the air conditioner 1 is operated, the operation is often switched between the reheat dehumidifying operation and the cooling operation. According to the embodiment illustrated in FIGS. 2 and 3, when switching from the reheat dehumidifying operation to the cooling operation, the compressor 9 passes through the first line 10, the reheat heat exchanger 7, and the second line 11. The refrigerant that has been supplied to the outdoor heat exchanger 4 is supplied from the compressor 9 to the outdoor heat exchanger 4 via the sixth line 16. The flow path through which the refrigerant circulates from the outdoor heat exchanger 4 to the compressor 9 via the third line 12, the indoor heat exchanger 6, and the fourth line 13 is either in a reheat dehumidifying operation or a cooling operation. Is also common. When the air conditioner 1 is switched between the reheat dehumidifying operation and the cooling operation, the reversal of the flow direction of the refrigerant flowing through each line does not occur. Since it does not require time for the refrigerant flow direction to reverse, it is advantageous to quickly switch the operation of the air conditioner 1 between the reheat dehumidifying operation and the cooling operation.

  As shown in the embodiment of FIG. 1, in the present invention, the fifth line 15 and the sixth line 16 are not essential components. In the case where the air conditioner 1 is a dedicated dehumidifier that performs only the reheat dehumidification operation, the embodiment illustrated in FIG. 1 can be employed. By adding the fifth line 15 and the sixth line 16 to the embodiment of FIG. 1, the air conditioner 1 can perform the heating operation and the cooling operation in addition to the reheat dehumidifying operation.

  For example, the air conditioner 1 may be configured to perform the reheat dehumidifying operation, the heating operation, and the cooling operation by adding only the sixth line 16 to the embodiment of FIG. That is, the air conditioner 1 that does not include the fifth line 15 may be used. When the air conditioner 1 performs the heating operation, the refrigerant compressed by the compressor 9 is supplied from the reheat heat exchanger 7 to the outdoor heat exchanger 4 via the second line 11.

  The air conditioner 1 that can switch between the heating operation and the cooling operation in addition to the reheat dehumidifying operation can be specifically configured as exemplified in FIG. The air conditioner 1 illustrated in FIG. 4 includes a pipe P1 that allows the compressor 9 and the reheat heat exchanger 7 to communicate with each other. A valve 17a is installed in the middle of the pipe P1. The valve 17a only needs to have a configuration capable of opening and closing a flow path formed by the pipe P1, and may be configured by, for example, an electromagnetic valve.

  The air conditioner 1 includes a pipe P2 that branches from a portion between the compressor 9 and the valve 17a in the pipe P1 and communicates with the heat exchanger 7 for reheating. A check valve 18a and a valve 17b are installed in the middle of the pipe P2 in this order from the reheat heat exchanger 7 side. The check valve 18 a has a configuration that allows the refrigerant to pass only in the direction from the reheat heat exchanger 7 to the compressor 9. The valve 17b can be constituted by, for example, an electromagnetic valve, like the valve 17a.

  In the pipe P2, the air conditioner 1 includes a pipe P3 that branches from a portion between the check valve 18a and the valve 17b and communicates with the outdoor heat exchanger 4. A four-way valve 19 is installed in the middle of the pipe P3.

  The air conditioner 1 includes a pipe P4 that allows the outdoor heat exchanger 4 and the indoor heat exchanger 6 to communicate with each other. A check valve 18b, a liquid receiver 20, an expansion valve 14, and a check valve 18c, which are arranged in order from the outdoor heat exchanger 4 side, are installed in the middle of the pipe P4. The check valve 18 b and the check valve 18 c have a configuration that allows the refrigerant to pass only in the direction from the outdoor heat exchanger 4 toward the indoor heat exchanger 6.

  The air conditioner 1 includes a pipe P5 that branches from a portion between the check valve 18c and the indoor heat exchanger 6 and communicates with the liquid receiver 20 in the pipe P4. A check valve 18d is installed in the middle of the pipe P5. The check valve 18d has a configuration in which the refrigerant is allowed to pass only in the direction from the portion between the check valve 18c and the indoor heat exchanger 6 toward the liquid receiver 20.

  The air conditioner 1 includes a pipe P6 that branches from a portion between the expansion valve 14 and the check valve 18c in the pipe P4 and communicates with the outdoor heat exchanger 4. A check valve 18e is installed in the middle of the pipe P6. The check valve 18e has a configuration in which the refrigerant is allowed to pass only from the portion between the expansion valve 14 and the check valve 18c toward the outdoor heat exchanger 4.

  The air conditioner 1 is provided with a pipe P7 that allows the indoor heat exchanger 6 and the four-way valve 19 to communicate with each other. The air conditioner 1 includes a pipe P8 that communicates the four-way valve 19 and the compressor 9. An accumulator 21 is installed in the middle of the pipe P8.

  The valves 17a, 17b, and the four-way valve 19 installed in the air conditioner 1 may be collectively referred to as a switching mechanism 22. The air conditioner 1 can appropriately switch the flow path through which the refrigerant flows by the switching mechanism 22.

  Next, the operating state of the air conditioner 1 of this embodiment will be described. As illustrated in FIG. 5, when the air conditioner 1 performs the reheat dehumidifying operation, the switching mechanism 22 controls the valve 17 a to be in an open state and the valve 17 b to be in a closed state. Further, the four-way valve 19 is controlled so as to communicate the pipe P2 and the pipe P3 and communicate the pipe P7 and the pipe P8. In FIG. 5, the flow path through which the refrigerant does not pass during the reheat dehumidification operation is indicated by a broken line for explanation.

  In the embodiment illustrated in FIG. 5, the valve 17a is in an open state and the valve 17b is in a closed state. Therefore, the refrigerant discharged from the compressor 9 does not flow into the pipe P2, passes through the valve 17a, and is supplied to the reheat heat exchanger 7. That is, the 1st line 10 which connects the compressor 9 and the heat exchanger 7 for reheating is comprised with the pipe P1. In the reheat heat exchanger 7, the refrigerant heats the inside air.

  The refrigerant deprived of heat by the reheat heat exchanger 7 passes through the pipe P2, the four-way valve 19, and the pipe P3, and is supplied to the outdoor heat exchanger 4. That is, the 2nd line 11 which connects the heat exchanger 7 for reheating and the outdoor heat exchanger 4 is comprised by the pipe P2 and the pipe P3. In the outdoor heat exchanger 4, the refrigerant is cooled by outside air.

  The refrigerant deprived of heat by the outdoor heat exchanger 4 passes through the pipe P4 and is supplied to the indoor heat exchanger 6. That is, the 3rd line 12 which connects the outdoor heat exchanger 4 and the indoor heat exchanger 6 is comprised by the pipe P4. The refrigerant that has been decompressed by the expansion valve 14 in the middle of passing through the pipe P4 and becomes low-temperature and low-pressure wet steam is supplied to the indoor heat exchanger 6. In the indoor heat exchanger 6, the refrigerant cools the inside air.

  The refrigerant that has absorbed heat from the inside air in the indoor heat exchanger 6 passes through the pipe P7, the four-way valve 19, the pipe P8, and the accumulator 21, and is supplied to the compressor 9. That is, the 4th line 13 which connects the indoor heat exchanger 6 and the compressor 9 is comprised by the pipe P7 and the pipe P8. In the compressor 9, the refrigerant is pressurized to become high-temperature and high-pressure superheated steam.

  As illustrated in FIG. 6, when the air conditioner 1 performs the heating operation, the switching mechanism 22 controls the valve 17 a to be in an open state and the valve 17 b to be in a closed state. Further, the four-way valve 19 is controlled so as to communicate the pipe P2 and the pipe P7 and communicate the pipe P3 and the pipe P8. In FIG. 6, the flow path through which the refrigerant does not pass during the heating operation is indicated by a broken line for the sake of explanation.

  The refrigerant which is compressed by the compressor 9 and becomes a high temperature and high pressure is supplied to the reheat heat exchanger 7 via the first line 10 constituted by the pipe P1. In the reheat heat exchanger 7, the refrigerant heats the inside air.

  The refrigerant deprived of heat by the reheat heat exchanger 7 passes through the pipe P2, the four-way valve 19, and the pipe P7 and is supplied to the indoor heat exchanger 6. That is, the 5th line 15 which connects the heat exchanger 7 for reheating and the indoor heat exchanger 6 is comprised by the pipe P2 and the pipe P7. Some pipes P2, P7 used as the second line 11 or the fourth line 13 during the reheat dehumidifying operation are used as the fifth line 15 during the heating operation by switching the four-way valve 19. . In the indoor heat exchanger 6, the refrigerant heats the inside air.

The refrigerant deprived of heat by the indoor heat exchanger 6 passes through the pipe P5, a part of the pipe P4, and the pipe P6 and is supplied to the outdoor heat exchanger 4. That is, the third line 12 that communicates the indoor heat exchanger 6 and the outdoor heat exchanger 4 is constituted by a part of the pipe P4, the pipe P5, and the pipe P6. Since the refrigerant passes through a part of the pipe P4 where the expansion valve 14 is installed, the refrigerant becomes low temperature and low pressure and is supplied to the outdoor heat exchanger 4. In the outdoor heat exchanger 4, the refrigerant is heated by the outside air.

  Four check valves 18b, 18c, 18d, and 18e are arranged on the pipe P4, the pipe P5, and the pipe P6 constituting the third line 12 during the reheat dehumidifying operation and the heating operation. Even if the flow direction of the refrigerant flowing through the third line 12 is reversed by this configuration, the flow direction of the refrigerant passing through the expansion valve 14 after passing through the liquid receiver 20 is maintained.

  The refrigerant that has absorbed heat in the outdoor heat exchanger 4 passes through the pipe P3, the four-way valve 19, the pipe P8, and the accumulator 21, and is supplied to the compressor 9. That is, the sixth line 16 that connects the outdoor heat exchanger 4 and the compressor 9 is constituted by the pipe P3 and the pipe P8.

  As illustrated in FIG. 7, when the air conditioner 1 performs a cooling operation, the switching mechanism 22 controls the valve 17 a to be closed and the valve 17 b to be opened. Further, the four-way valve 19 is controlled so that a part of the pipe P2 communicates with the pipe P3 and the pipe P7 and the pipe P8 communicate with each other. In FIG. 7, the flow path through which the refrigerant does not pass during the cooling operation is indicated by a broken line for the sake of explanation.

  In the embodiment illustrated in FIG. 7, the valve 17a is in a closed state and the valve 17b is in an open state. Therefore, the refrigerant discharged from the compressor 9 does not flow into the pipe P1, passes through the valve 17b, and is supplied to the outdoor heat exchanger 4. That is, the sixth line 16 that connects the compressor 9 and the outdoor heat exchanger 4 is constituted by a part of the pipe P2 and the pipe P3. In the outdoor heat exchanger 4, the refrigerant is cooled by outside air.

  The refrigerant deprived of heat by the outdoor heat exchanger 4 passes through the pipe P4 and is supplied to the indoor heat exchanger 6. That is, the 3rd line 12 which connects the outdoor heat exchanger 4 and the indoor heat exchanger 6 is comprised by the pipe P4. The refrigerant that has been depressurized by the expansion valve 14 in the middle of passing through the pipe P4 to become low temperature and low pressure is supplied to the indoor heat exchanger 6. In the indoor heat exchanger 6, the refrigerant cools the inside air.

  The refrigerant that has absorbed heat from the inside air in the indoor heat exchanger 6 passes through the pipe P7, the four-way valve 19, the pipe P8, and the accumulator 21, and is supplied to the compressor 9. That is, the 4th line 13 which connects the indoor heat exchanger 6 and the compressor 9 is comprised by the pipe P7 and the pipe P8.

  As illustrated in FIGS. 4 to 7, the air conditioner 1 of the present embodiment can perform a reheat dehumidifying operation, a heating operation, and a cooling operation. The embodiment illustrated in FIGS. 4 to 7 is merely an example, and the valve 17 and the check valve 18 can be appropriately added or removed. Further, the layout of the pipes P can be changed as appropriate. For example, the same effect as that of the present invention can be obtained by installing a valve 17 that can control opening and closing of an electromagnetic valve or the like instead of the check valve 18.

1 Air Conditioner 2 Outdoor Unit 3 Indoor Unit 4 Outdoor Heat Exchanger 5 Outdoor Blower 6 Indoor Heat Exchanger 7 Reheat Heat Exchanger 8 Indoor Blower 9 Compressor 10 First Line 11 Second Line 12 Third Line 13 Fourth Line 14 Expansion valve 15 Fifth line 16 Sixth line 17, 17a, 17b Valve 18, 18a, 18b, 18c, 18d Check valve 19 Four-way valve 20 Receiving device 21 Accumulator 22 Switching mechanism P, P1-P8 Pipe

Claims (6)

A compressor that compresses the refrigerant; an expansion valve that decompresses the refrigerant; an outdoor heat exchanger that is installed in the outdoor unit to exchange heat between the refrigerant and the outside air; and In a heat pump type air conditioner comprising an indoor heat exchanger that performs heat exchange with the heat exchanger and a heat exchanger for reheating,
The reheat heat exchanger has a configuration installed on the downstream side of the indoor heat exchanger in the direction of flow of the inside air passing through the indoor unit,
A first line for supplying the refrigerant to be compressed by the compressor to the heat exchanger for reheating;
A second line for supplying refrigerant discharged from the reheat heat exchanger to the outdoor heat exchanger;
A third line communicating the outdoor heat exchanger and the indoor heat exchanger and installing the expansion valve in the middle part;
And a fourth line for supplying the refrigerant discharged from the indoor heat exchanger to the compressor.   The fifth line for supplying the refrigerant discharged from the heat exchanger for reheating to the indoor heat exchanger, and a sixth line for communicating the outdoor heat exchanger and the compressor. Air conditioner. A switching mechanism for switching the refrigerant flow path,
By the switching mechanism,
The refrigerant discharged from the compressor passes through the first line, the reheat heat exchanger, the second line, the outdoor heat exchanger, the third line, the indoor heat exchanger, and the fourth line. The state of the reheat dehumidification operation flowing to the compressor via in order,
The refrigerant discharged from the compressor passes through the first line, the reheat heat exchanger, the fifth line, the indoor heat exchanger, the third line, the outdoor heat exchanger, and the sixth line. The air conditioner of Claim 2 comprised so that switching of the state of the heating operation which flows into the said compressor via in order is possible. A compressor that compresses the refrigerant; an expansion valve that depressurizes the refrigerant; an outdoor heat exchanger that is installed in the outdoor unit and performs heat exchange between the refrigerant and the outside air; and In a control method of a heat pump type air conditioner including an indoor heat exchanger that performs heat exchange with the heat exchanger and a heat exchanger for reheating,
Installing the reheat heat exchanger on the downstream side of the indoor heat exchanger in the flow direction of the inside air passing through the indoor unit;
During the reheat dehumidifying operation, the refrigerant compressed by the compressor is supplied to the reheat heat exchanger, and the outdoor heat exchange is performed for the refrigerant deprived of heat from the inside air by the reheat heat exchanger. A control method, comprising: supplying to the indoor heat exchanger after depressurizing the refrigerant that has been deprived of heat to the outside air by the outdoor heat exchanger with the expansion valve.   During the heating operation, the refrigerant compressed by the compressor is supplied to the reheat heat exchanger, and the refrigerant deprived of heat by the reheat heat exchanger to the indoor heat exchanger. The control method according to claim 4, wherein the refrigerant that has been supplied and depressurized by the expansion valve is supplied to the outdoor heat exchanger after the refrigerant deprived of heat in the indoor air by the indoor heat exchanger.   The control method according to claim 5, wherein during the heating operation, the entire amount is supplied to the indoor heat exchanger without reducing the pressure of the refrigerant discharged from the reheat heat exchanger.

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