Air Conditioning Equipment

Abstract

To provide an air conditioner which enables vacuum drawing of a medium pipe of an indoor unit to be easily performed while inhibiting design change of an existing component when the indoor unit and an outdoor unit are connected.SOLUTION: An air conditioner includes an indoor heat exchanger, an outdoor heat exchanger, a first pipe, a second pipe, a compressor, a four-way valve, a first on-off valve, a second on-off valve, a first selector valve, and an atmospheric air releasing part. The compressor is provided at the first pipe and has a suction port for suctioning a refrigerant and a discharge port for discharging the refrigerant. The first on-off valve may close the first pipe connected to the indoor heat exchanger. The second on-off valve may close the second pipe connected to the indoor heat exchanger. The first selector valve is provided at the first pipe between the discharge port and the four-way valve and switches a passage between a first switch passage which connects the discharge port with the four-way valve and a second switch passage different from the first switch passage. The atmospheric air releasing part releases a gas to atmospheric air through the second switch passage.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] An embodiment of the present invention relates to an air conditioning apparatus. [Background technology]

[0002] An air conditioner, such as an air conditioner, adjusts the temperature inside the room by condensing and evaporating a refrigerant in a refrigeration cycle. In general, an outdoor unit is filled with refrigerant at a factory or the like during manufacturing and is transported to the installation site of the air conditioner in a sealed state. Meanwhile, an indoor unit is transported to the installation site without being filled with refrigerant (with air, volatile gas, or other gases in the refrigerant piping). Then, at the installation site of the air conditioner, preparatory work such as vacuuming the refrigerant piping of the indoor unit is performed, and the refrigerant piping of the indoor unit is connected to the refrigerant piping of the outdoor unit in a state in which the gas in the refrigerant piping of the indoor unit is removed. As a result, the refrigerant that was filled on the outdoor unit side moves to the indoor unit side, and the refrigerant piping is filled with refrigerant. The above-mentioned vacuuming work is performed, for example, using a vacuum pump brought to the installation site. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2007-71421 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the task of bringing a vacuum pump to the installation site each time increases installation costs and reduces installation work efficiency. In addition, when performing vacuuming using the compressor disclosed in Patent Document 1, a general compressor cannot be used, which may increase product costs.

[0005] One example of a problem that the present invention solves is to provide an air conditioning apparatus that can easily evacuate the medium piping of the indoor unit while minimizing the need to make design changes to existing components when connecting the indoor unit and outdoor unit. [Means for solving the problem]

[0006] An air conditioning apparatus according to one embodiment of the present invention includes an indoor heat exchanger, an outdoor heat exchanger, a first pipe, a second pipe, a compressor, a four-way valve, a first on-off valve, a second on-off valve, a first switching valve, and an atmosphere opening section. A third pipe, a second switching valve, and a third switching valve, The first pipe connects the indoor heat exchanger and the outdoor heat exchanger, and a refrigerant flows through the first pipe. The second pipe connects the outdoor heat exchanger and the indoor heat exchanger, and the refrigerant flows through the second pipe. The compressor is provided in the first pipe and has an intake port for sucking the refrigerant and an outlet port for discharging the refrigerant. The four-way valve is provided in the first pipe and is capable of changing the direction in which the refrigerant flows. The first opening / closing valve is capable of closing the first pipe connected to the indoor heat exchanger. The second opening / closing valve is capable of closing the second pipe connected to the indoor heat exchanger. The first switching valve is provided in the first pipe between the outlet port and the four-way valve, and switches between a first switching flow path connecting the outlet port to the four-way valve and a second switching flow path different from the first switching flow path. The atmosphere opening unit opens the second switching flow path to the atmosphere. A third pipe is connected to the first pipe between the four-way valve and the first on-off valve and the suction port. A second switching valve is provided at one end of the third pipe and switches between a first connection state in which the first on-off valve and the third pipe are connected and a second connection state in which the first on-off valve and the four-way valve are connected. A third switching valve is provided at the other end of the third pipe and switches between a third connection state in which the suction port and the third pipe are connected and a fourth connection state in which the suction port and the four-way valve are connected.

[0008] Furthermore, the first pipe of the air conditioner may include, for example, a pressure detection unit that detects the pressure of the suction port.

[0009] The air conditioning apparatus may further include, for example, a first expansion valve provided in the second piping between the second opening / closing valve and the outdoor heat exchanger, a second expansion valve provided in the third piping between the second switching valve and a third switching valve, and an in-flow path heat exchanger provided between the second expansion valve and the third switching valve.

[0010] Furthermore, the third pipe of the air conditioner may include, for example, a solenoid valve between the second switching valve and the third switching valve.

[0011] According to the above air conditioning device, for example, when connecting an indoor unit and an outdoor unit, it is possible to provide an air conditioning device that can easily evacuate the medium piping of the indoor unit while minimizing the need to make design changes to existing components. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is an exemplary schematic diagram showing a refrigerant system diagram of an air conditioner according to a first embodiment. [Diagram 2] FIG. 2 is an exemplary schematic diagram showing another refrigerant system diagram of the air conditioner according to the second embodiment. [Diagram 3] FIG. 3 is an exemplary schematic diagram showing the flow of refrigerant when the air conditioner having the configuration in FIG. 2 is operated in normal cooling mode when the outdoor air temperature is below a predetermined value. [Figure 4] FIG. 4 is an exemplary schematic diagram showing the flow of refrigerant when the air conditioner having the configuration in FIG. 2 is operated in energy-saving cooling operation when the outdoor air temperature is equal to or higher than a predetermined value. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Several embodiments will be described below with reference to Figs. 1 to 4. In this specification, components according to the embodiments and their descriptions may be described in a number of ways. The components and their descriptions are merely examples and are not limited by the expressions in this specification. The components may be identified by names different from those in this specification. The components may also be described by expressions different from those in this specification.

[0014] First Embodiment 1 is a refrigerant system diagram of an air conditioner 10A according to a first embodiment, and is an exemplary and schematic diagram showing the connection state of piping when evacuating the refrigerant piping installation vacuum region when installing the air conditioner 10A. The air conditioner 10A is, for example, a home air conditioner. Note that the air conditioner 10A is not limited to this example, and may be another air conditioner such as a commercial air conditioner.

[0015] 1, an air conditioner 10A has an outdoor unit 11, an indoor unit 12, refrigerant piping 13, and a control device 14. The outdoor unit 11 is disposed, for example, outdoors. The indoor unit 12 is disposed, for example, indoors.

[0016] The air conditioning device 10A includes a refrigeration cycle in which an outdoor unit 11 and an indoor unit 12 are connected by refrigerant piping 13. A refrigerant flows between the outdoor unit 11 and the indoor unit 12 through the refrigerant piping 13. In addition, the outdoor unit 11 and the indoor unit 12 are electrically connected to each other by, for example, electrical wiring.

[0017] The outdoor unit 11 has an outdoor heat exchanger 21, an outdoor blower fan 22, a compressor 23, an accumulator 24, a four-way valve 25, a first expansion valve 31, a first on-off valve 33, a second on-off valve 32, a first switching valve 34, and an atmosphere opening section 35. The indoor unit 12 has an indoor heat exchanger 41 and an indoor blower fan 42.

[0018] The refrigerant pipe 13 is a pipe made of a metal such as copper or aluminum. The refrigerant pipe 13 has a first pipe 51 and a second pipe 52. The first pipe 51 connects the indoor heat exchanger 41 and the outdoor heat exchanger 21. The compressor 23, the accumulator 24, the four-way valve 25, the first on-off valve 33, the first switching valve 34, and the atmosphere opening part 35 are provided in the first pipe 51. The second pipe 52 connects the outdoor heat exchanger 21 and the indoor heat exchanger 41. The first expansion valve 31 and the second on-off valve 32 are provided in the second pipe 52.

[0019] In cooling operation, the refrigerant flows from the indoor heat exchanger 41 to the outdoor heat exchanger 21 through the first piping 51, and flows from the outdoor heat exchanger 21 to the indoor heat exchanger 41 through the second piping 52. In heating operation, the refrigerant flows from the outdoor heat exchanger 21 to the indoor heat exchanger 41 through the first piping 51, and flows from the indoor heat exchanger 41 to the outdoor heat exchanger 21 through the second piping 52.

[0020] The outdoor heat exchanger 21 of the outdoor unit 11 absorbs heat from the refrigerant as an evaporator or releases heat from the refrigerant as a condenser depending on the direction of refrigerant flow. The outdoor blower fan 22 blows air toward the outdoor heat exchanger 21 to promote heat exchange between the refrigerant and air in the outdoor heat exchanger 21. In other words, the outdoor blower fan 22 generates an airflow that exchanges heat with the outdoor heat exchanger 21.

[0021] The compressor 23 has a suction port 23a and a discharge port 23b. The compressor 23 draws in a refrigerant from the suction port 23a and discharges the compressed refrigerant from the discharge port 23b. In this way, the compressor 23 compresses the refrigerant in a refrigeration cycle and causes the refrigerant to circulate.

[0022] The accumulator 24 is connected to the suction port 23a of the compressor 23. The accumulator 24 separates the gaseous refrigerant from the liquid refrigerant. This allows the compressor 23 to suck the gaseous refrigerant that has passed through the accumulator 24 from the suction port 23a. The accumulator 24 can also function as the suction port of the compressor 23 by being configured integrally with the compressor 23.

[0023] The first switching valve 34 is connected to the discharge port 23b of the compressor 23, the four-way valve 25, and the atmosphere opening section 35. The first switching valve 34 switches the flow path during normal operation in which cooling operation, heating operation, dehumidification operation, defrosting operation, and other operations are performed, and during installation work for installing the air conditioner 10A. That is, during normal operation, the first switching valve 34 connects the discharge port 23b and the four-way valve 25, switches to the first switching flow path, and flows the refrigerant to the four-way valve 25. On the other hand, during installation work, the first switching valve 34 connects the discharge port 23b and the atmosphere opening section 35, switches to the second switching flow path, and releases gas that is unnecessary during normal operation of the air conditioner 10A that is present in the refrigerant piping 13 of the indoor unit 12 and the outdoor unit 11 during installation work to the atmosphere. The atmosphere opening section 35 can be configured, for example, as a manual on-off valve, which is opened when unnecessary gas is released to the atmosphere and closed otherwise. Basically, the atmosphere opening section 35 is not used after the installation work of the air conditioning device 10A is completed. Therefore, the atmosphere opening section 35 may be fixed in a closed state when the installation work is completed. Similarly, the first switching valve 34 may be fixed in a state in which the discharge port 23b and the four-way valve 25 are connected when the installation work is completed.

[0024] The four-way valve 25 is connected to the outdoor heat exchanger 21, the indoor heat exchanger 41, the discharge port 23b of the compressor 23 via the first switching valve 34, and the accumulator 24 (the suction port 23a of the compressor 23). The four-way valve 25 switches the flow paths connected to the outdoor heat exchanger 21, the indoor heat exchanger 41, the discharge port 23b of the compressor 23, and the accumulator 24, respectively, during heating operation and cooling operation, to change the direction in which the refrigerant flows.

[0025] During cooling operation, the first switching valve 34 connects the discharge port 23b to the four-way valve 25. The four-way valve 25 also connects the discharge port 23b of the compressor 23 via the first switching valve 34 to the outdoor heat exchanger 21. Furthermore, during cooling operation, the four-way valve 25 connects the indoor heat exchanger 41 to the accumulator 24. As a result, the refrigerant compressed by the compressor 23 flows to the outdoor heat exchanger 21, and the refrigerant that has undergone heat exchange (e.g., evaporated) in the indoor heat exchanger 41 flows to the accumulator 24.

[0026] During heating operation, the first switching valve 34 connects the discharge port 23b to the four-way valve 25. The four-way valve 25 connects the outdoor heat exchanger 21 to the accumulator 24. During heating operation, the four-way valve 25 connects the discharge port 23b of the compressor 23 via the first switching valve 34 to the indoor heat exchanger 41. As a result, the refrigerant compressed by the compressor 23 flows to the indoor heat exchanger 41, and the refrigerant that has undergone heat exchange (e.g., evaporated) in the outdoor heat exchanger 21 flows to the accumulator 24.

[0027] The first expansion valve 31 is, for example, an electromagnetic expansion valve. However, the first expansion valve 31 may be another type of expansion valve. The first expansion valve 31 adjusts the amount of refrigerant passing through by controlling the opening degree.

[0028] The first on-off valve 33 and the second on-off valve 32 are, for example, manual on-off valves. The first on-off valve 33 and the second on-off valve 32 are closed in a state where the first pipe 51 and the second pipe 52 of the outdoor unit 11 are filled with refrigerant, for example, at the time of manufacturing the outdoor unit 11 in a factory or the like. Then, as described below, the first on-off valve 33 and the second on-off valve 32 are selectively opened and closed when the air conditioning device 10A is installed (when the outdoor unit 11 and the indoor unit 12 are installed), thereby degassing (vacuuming) the piping portion not filled with refrigerant. The first on-off valve 33 and the second on-off valve 32 are maintained in an open state during normal operation of the air conditioning device 10A. Therefore, the first on-off valve 33 and the second on-off valve 32 may also be fixed to maintain an open state after the installation work is completed and before the start of normal operation.

[0029] The indoor heat exchanger 41 of the indoor unit 12 absorbs heat as an evaporator or releases heat as a condenser depending on the direction of refrigerant flow. The indoor blower fan 42 blows air toward the indoor heat exchanger 41 to promote heat exchange between the indoor heat exchanger 41 and the air. In other words, the indoor blower fan 42 generates an airflow that exchanges heat with the indoor heat exchanger 41.

[0030] The control device 14 includes, for example, an outdoor control device 14a and an indoor control device 14b. The outdoor control device 14a and the indoor control device 14b are electrically connected to each other by electrical wiring. At least one of the outdoor control device 14a and the indoor control device 14b is, for example, a computer having a control device such as a CPU (Central Processing Unit) or a microcontroller, and a storage device such as a ROM (Read Only Memory), a RAM (Random Access Memory), and a flash memory. Note that the control device 14 is not limited to this example. For example, the control device 14 may include only one of the outdoor control device 14a and the indoor control device 14b.

[0031] The outdoor control device 14a controls the outdoor blower fan 22, the compressor 23, the four-way valve 25, and the first expansion valve 31 of the outdoor unit 11. The indoor control device 14b controls the indoor blower fan 42 of the indoor unit 12.

[0032] The air conditioning apparatus 10A performs cooling operation, heating operation, dehumidification operation, defrosting operation, and other operations by the control device 14 controlling the outdoor unit 11 and the indoor unit 12. The indoor control device 14b may receive signals, for example, from a remote controller, or may receive signals from an information terminal such as a smartphone via a communication device.

[0033] As described above, the refrigerant pipe 13 of the outdoor unit 11 is filled with refrigerant when shipped from the factory, but the refrigerant pipe 13 of the indoor unit 12 is not filled with refrigerant. For example, air is present in the refrigerant pipe 13 of the indoor unit 12 when shipped from the factory. The refrigerant pipe 13 of the indoor unit 12 when shipped from the factory can also be filled with an inert gas (e.g., nitrogen gas) to prevent corrosion, etc. In other words, when connecting the refrigerant pipe 13 of the outdoor unit 11 to the refrigerant pipe 13 of the indoor unit 12 at the installation location of the air conditioning device 10A, first, an operation of discharging gas such as air from the refrigerant pipe 13 of the indoor unit 12 (vacuum operation to substantially create a vacuum state) is required. Then, after the vacuum operation is completed, the refrigerant pipe 13 of the indoor unit 12 is connected to the refrigerant pipe 13 of the outdoor unit 11, and the refrigerant filled on the outdoor unit 11 side must be filled on the indoor unit 12 side. Conventionally, a vacuum pump or the like was connected to place the refrigerant piping 13 of the indoor unit 12 in a substantial vacuum state, but in the case of the air conditioner 10A of this embodiment, the compressor 23 used during normal operation, which is mounted in the outdoor unit 11, is used to place the refrigerant piping 13 of the indoor unit 12 in a substantial vacuum state. The procedure for installing the air conditioner 10A will be described below.

[0034] First, the outdoor unit 11 is installed at a predetermined position outdoors. At the time of shipment from the factory, the first switching valve 34 is connected to the atmospheric open section 35, and the atmospheric open section 35 is in a closed state. The four-way valve 25 is in the same state as during cooling operation, for example. That is, the four-way valve 25 is in a state in which the discharge port 23b of the compressor 23 and the outdoor heat exchanger 21 can be connected via the first switching valve 34. The four-way valve 25 is in a state in which the indoor heat exchanger 41 and the accumulator 24 can be connected. In this state, the second pipe 52 connecting the second opening / closing valve 32 and the outdoor heat exchanger 21 and the first pipe 51 connecting the outdoor heat exchanger 21 and the first switching valve 34 are filled with refrigerant. The first opening / closing valve 33 and the second opening / closing valve 32 are maintained in a closed state, and the refrigerant filled in the outdoor unit 11 is maintained in a sealed state.

[0035] The indoor unit 12 is installed at a predetermined position in the room. A first area 51a, which is a part of the first piping 51 of the indoor heat exchanger 41 of the indoor unit 12, is connected to the first on-off valve 33 of the outdoor unit 11. Similarly, a third area 52a, which is a part of the second piping 52 of the indoor heat exchanger 41, is connected to the second on-off valve 32 of the outdoor unit 11.

[0036] Next, the first on-off valve 33 and the atmospheric open section 35 are switched to an open state. When the compressor 23 is operated in this state, gas such as air, moisture, dust, etc. present in the third region 52a of the second piping 52, the indoor heat exchanger 41, the first region 51a of the first piping 51, and the installation vacuum region from the first on-off valve 33 to the accumulator 24 (the suction port 23a of the compressor 23) in the first piping 51 are sucked by the compressor 23 and discharged from the atmospheric open section 35. This discharge operation is continued for a predetermined period (a vacuum drawing time determined in advance by testing, etc.) until the installation vacuum region reaches a predetermined state (a substantial vacuum state: for example, -100 KPa).

[0037] After a predetermined period of time has elapsed, or after a sensor (not shown) or the like has detected that the initial vacuum region has reached a predetermined state, the atmospheric release section 35 is closed. Simultaneously with or after this valve closure, the first switching valve 34 is switched to connect the four-way valve 25 to the suction port 23a of the compressor 23. Then, the second on-off valve 32 is opened. As a result, the refrigerant that had been filled in the outdoor unit 11 flows into the initial vacuum region where a substantial vacuum state has been created by the operation of the compressor 23, and the refrigerant is filled into the refrigerant piping 13 through which the refrigerant circulates during normal operation.

[0038] In this way, by simply switching the first on-off valve 33, the second on-off valve 32, the first switching valve 34, and the atmosphere release section 35, it is possible to substantially evacuate the installation vacuum area including the refrigerant piping 13 of the indoor unit 12 using the compressor 23 installed in the outdoor unit 11 for normal operation. As a result, the installation work of the air conditioner 10A (outdoor unit 11, indoor unit 12) can be easily and quickly performed. In addition, it is possible to perform the above-mentioned evacuation work by simply using the compressor 23 provided in the conventional air conditioner as it is and adding the first switching valve 34 and the atmosphere release section 35 downstream of the discharge port 23b of the compressor 23. As a result, it is possible to contribute to suppressing a significant increase in the product cost of the air conditioner 10A and suppressing a significant design change of the air conditioner 10A.

[0039] <Second embodiment> FIG. 2 is a refrigerant system diagram of an air conditioner 10B according to a second embodiment, and is an exemplary and schematic diagram showing the connection state of piping when the refrigerant piping installation vacuum region is vacuumed when the air conditioner 10B is installed. The air conditioner 10B is also, for example, a home air conditioner. Note that the air conditioner 10B is not limited to this example, and may be other air conditioners such as a commercial air conditioner. Note that the same reference numerals are used to designate members having substantially the same configuration as the air conditioner 10A described in the first embodiment.

[0040] 2, the air conditioner 10B also has an outdoor unit 11, an indoor unit 12, refrigerant piping 13, and a control device 14. The outdoor unit 11 is disposed, for example, outdoors. The indoor unit 12 is disposed, for example, indoors.

[0041] The air conditioner 10B includes a refrigeration cycle in which an outdoor unit 11 and an indoor unit 12 are connected by refrigerant piping 13. A refrigerant flows between the outdoor unit 11 and the indoor unit 12 through the refrigerant piping 13. In addition, the outdoor unit 11 and the indoor unit 12 are electrically connected to each other by, for example, electrical wiring.

[0042] The outdoor unit 11 of the air conditioner 10B has an outdoor heat exchanger 21, an outdoor blower fan 22, a compressor 23, an accumulator 24, a four-way valve 25, a first expansion valve 31, a first on-off valve 33, a second on-off valve 32, a first switching valve 34, and an atmospheric open section 35, similar to the outdoor unit 11 of the air conditioner 10A. The outdoor unit 11 of the air conditioner 10B also includes a second switching valve 61, a solenoid valve 62, a filter dryer 63, a second expansion valve 64, a third switching valve 65, and an in-flow heat exchanger 70. The indoor unit 12 has an indoor heat exchanger 41 and an indoor blower fan 42.

[0043] The refrigerant pipe 13 is a pipe made of a metal such as copper or aluminum. The refrigerant pipe 13 has a first pipe 51, a second pipe 52, and a third pipe 53. The first pipe 51 includes a first region 51a included in the indoor unit 12 and a second region 51b included in the outdoor unit 11, and connects the indoor heat exchanger 41 and the outdoor heat exchanger 21. The compressor 23, the accumulator 24, the four-way valve 25, the first on-off valve 33, the first switching valve 34, and the atmosphere opening section 35 are provided in the second region 51b of the first pipe 51. The second pipe 52 includes a third region 52a included in the indoor unit 12, a fourth region 52b included in the outdoor unit 11 between the outdoor heat exchanger 21 and the in-flow heat exchanger 70, and a fifth region 52c between the first expansion valve 31 and the second on-off valve 32, and connects the outdoor heat exchanger 21 and the indoor heat exchanger 41. The first expansion valve 31 and the second on-off valve 32 are provided in the fifth region 52c of the second pipe 52, and the in-flow heat exchanger 70 is provided in the fourth region 52b. The third pipe 53 has one end connected to the first pipe 51 and the other end connected to the third switching valve 65. That is, the third pipe 53 functions as a bypass pipe that bypasses the second region 51b (four-way valve 25) of the first pipe 51 connected to the indoor heat exchanger 41 and connects to the compressor 23 (accumulator 24). The third piping 53 is a piping that can be used when performing the vacuum work of the refrigerant piping 13 of the indoor unit 12 described in the air conditioner 10A. The second changeover valve 61, the solenoid valve 62, the filter dryer 63, the second expansion valve 64, and the third changeover valve 65 are provided in the third piping 53. Note that the third piping 53 is also a piping that can be used when performing energy saving operation or dehumidification operation of the air conditioner 10B when the outside temperature is high (for example, 35°C or higher). Details regarding the vacuum work and energy saving cooling operation using the third piping 53 will be described later.

[0044] In cooling operation, the refrigerant flows from the indoor heat exchanger 41 to the outdoor heat exchanger 21 through the first piping 51, and flows from the outdoor heat exchanger 21 to the indoor heat exchanger 41 through the second piping 52. In heating operation, the refrigerant flows from the outdoor heat exchanger 21 to the indoor heat exchanger 41 through the first piping 51, and flows from the indoor heat exchanger 41 to the outdoor heat exchanger 21 through the second piping 52. The arrows in Fig. 2 indicate the flow of gases and the like to be exhausted when evacuating the vacuum region at the time of installation of the refrigerant piping, which will be described later.

[0045] The outdoor heat exchanger 21 of the outdoor unit 11 absorbs heat from the refrigerant as an evaporator or releases heat from the refrigerant as a condenser depending on the direction of refrigerant flow. The outdoor blower fan 22 blows air toward the outdoor heat exchanger 21 to promote heat exchange between the refrigerant and air in the outdoor heat exchanger 21. In other words, the outdoor blower fan 22 generates an airflow that exchanges heat with the outdoor heat exchanger 21.

[0046] The compressor 23 has a suction port 23a and a discharge port 23b. The compressor 23 draws in a refrigerant from the suction port 23a and discharges the compressed refrigerant from the discharge port 23b. In this way, the compressor 23 compresses the refrigerant in a refrigeration cycle and causes the refrigerant to circulate.

[0047] The accumulator 24 is connected to the suction port 23a of the compressor 23. The accumulator 24 separates the gaseous refrigerant from the liquid refrigerant. This allows the compressor 23 to suck the gaseous refrigerant that has passed through the accumulator 24 from the suction port 23a. The accumulator 24 can also function as the suction port of the compressor 23 by being configured integrally with the compressor 23.

[0048] The first switching valve 34 is connected to the discharge port 23b of the compressor 23, the four-way valve 25, and the atmosphere opening section 35. The first switching valve 34 switches the flow path during normal operation in which cooling operation, heating operation, dehumidification operation, defrosting operation, and other operations are performed, and during installation work for installing the air conditioner 10B. That is, during normal operation, the first switching valve 34 connects the discharge port 23b and the four-way valve 25, switches to the first switching flow path, and flows the refrigerant to the four-way valve 25. On the other hand, during installation work, the first switching valve 34 connects the discharge port 23b and the atmosphere opening section 35, switches to the second switching flow path, and releases unnecessary gas that is present in the refrigerant piping 13 of the indoor unit 12 and the outdoor unit 11 during normal operation of the air conditioner 10B to the atmosphere during installation work. The atmosphere opening section 35 can be configured, for example, as a manual on-off valve, which is opened when unnecessary gas is released to the atmosphere and closed otherwise. Basically, the atmosphere opening section 35 is not used after the installation work of the air conditioning device 10B is completed. Therefore, when the installation work is completed, the atmosphere opening section 35 is fixed in a closed state. Similarly, the first switching valve 34 may be fixed in a state in which the discharge port 23b and the four-way valve 25 are connected when the installation work is completed.

[0049] The four-way valve 25 is connected to the outdoor heat exchanger 21, the indoor heat exchanger 41, the discharge port 23b of the compressor 23 via the first changeover valve 34, and the accumulator 24 (the suction port 23a of the compressor 23) via the third changeover valve 65. The four-way valve 25 switches the flow paths connected to the outdoor heat exchanger 21, the indoor heat exchanger 41, the discharge port 23b of the compressor 23, and the accumulator 24 via the third changeover valve 65 between heating operation and cooling operation, thereby changing the direction in which the refrigerant flows.

[0050] During cooling operation, the first switching valve 34 connects the discharge port 23b to the four-way valve 25. The four-way valve 25 also connects the discharge port 23b of the compressor 23 to the outdoor heat exchanger 21 via the first switching valve 34. Furthermore, during cooling operation, the four-way valve 25 connects the indoor heat exchanger 41 via the second switching valve 61 to the accumulator 24 via the third switching valve 65. As a result, the refrigerant compressed by the compressor 23 flows to the outdoor heat exchanger 21, and the refrigerant that has been heat exchanged (e.g., evaporated) in the indoor heat exchanger 41 flows to the accumulator 24. During high-load operation (energy-saving cooling operation) in which the outdoor air temperature is equal to or higher than a predetermined temperature (e.g., 35°C) in the cooling operation, the refrigerant is returned to the accumulator 24 through the third pipe 53 that bypasses the four-way valve 25. The flow of the refrigerant during high-load refrigerant operation will be described later.

[0051] During heating operation, the first switching valve 34 connects the discharge port 23b to the four-way valve 25. The four-way valve 25 connects the outdoor heat exchanger 21 to the accumulator 24. During heating operation, the four-way valve 25 connects the discharge port 23b of the compressor 23 via the first switching valve 34 to the indoor heat exchanger 41. As a result, the refrigerant compressed by the compressor 23 flows to the indoor heat exchanger 41, and the refrigerant that has undergone heat exchange (e.g., evaporated) in the outdoor heat exchanger 21 flows to the accumulator 24.

[0052] The first expansion valve 31 is, for example, an electromagnetic expansion valve. However, the first expansion valve 31 may be another type of expansion valve. The first expansion valve 31 adjusts the amount of refrigerant passing through by controlling the opening degree.

[0053] The first on-off valve 33 and the second on-off valve 32 are, for example, manual on-off valves. The first on-off valve 33 and the second on-off valve 32 are closed in a state where the first pipe 51 and the second pipe 52 of the outdoor unit 11 are filled with refrigerant, for example, at the time of manufacturing the outdoor unit 11 in a factory or the like. Then, as described later, the first on-off valve 33 and the second on-off valve 32 are selectively opened and closed during installation of the air conditioning device 10B (when the outdoor unit 11 and the indoor unit 12 are installed), thereby degassing (vacuuming) the piping portion not filled with refrigerant. The first on-off valve 33 and the second on-off valve 32 are maintained in an open state during normal operation of the air conditioning device 10B. Therefore, the first on-off valve 33 and the second on-off valve 32 may also be fixed to maintain an open state after the installation work is completed and before the start of normal operation.

[0054] The second switching valve 61 connects the indoor heat exchanger 41 to the third pipe 53 (first connection state) when performing vacuum work on the refrigerant pipe 13 of the indoor unit 12 during installation work of the air conditioner 10B and when performing energy-saving cooling operation or the like when the outdoor air temperature is a predetermined temperature (for example, 35°C) or higher. In addition, the second switching valve 61 connects the indoor heat exchanger 41 to the compressor 23 (accumulator 24) via the four-way valve 25 when performing rated operation when the outdoor air temperature is below the predetermined temperature. The state in which the first opening / closing valve 33 (indoor heat exchanger 41) and the four-way valve 25 are connected may also be referred to as the second connection state. In addition, during heating operation, the second switching valve 61 connects the suction port 23a via the four-way valve 25 to the indoor heat exchanger 41. The second switching valve 61 is, for example, a control valve that can be controlled to open and close.

[0055] The solenoid valve 62 is disposed between the second switching valve 61 and the filter dryer 63, and is a component for ensuring the sealing of the area (sixth area 53a, seventh area 53b) between the solenoid valve 62 and the third switching valve 65 in the third piping 53. As described above, the third piping 53 is used when performing the evacuation work when the air conditioning device 10B is installed. Therefore, the third piping 53 is not filled with refrigerant at the time of shipment from the factory. Instead, in order to prevent deterioration of the third piping 53, for example, corrosion, etc., the third piping 53 may be filled with an inert gas (for example, nitrogen gas) or the like. The solenoid valve 62 ensures the retention of the inert gas. Note that, when the closing of the first opening / closing valve 33 can ensure sufficient blocking of the third piping 53, the solenoid valve 62 may be omitted.

[0056] The filter dryer 63 is disposed in the third piping 53 between the solenoid valve 62 (second switching valve 61) and the third switching valve 65, and collects moisture, dust, and the like remaining in the piping, particularly when performing a vacuuming operation. In addition, during normal operation of the air conditioning device 10B, it can also collect abrasion powder and the like that may be generated by the compressor 23, etc.

[0057] The second expansion valve 64 is an electromagnetic expansion valve. The second expansion valve 64 may be another type of expansion valve. The second expansion valve 64 adjusts the amount of refrigerant passing through the third pipe 53 during cooling operation by controlling the opening degree. Note that the second expansion valve 64 is in an open state (fully open state) during the evacuation operation.

[0058] The third switching valve 65 is, for example, a three-way valve. The third switching valve 65 may be another switching valve capable of changing the direction in which the refrigerant flows, such as a four-way valve. When the second switching valve 61 is switched to the four-way valve 25, that is, during rated cooling operation, the third switching valve 65 connects the second region 51b of the first pipe 51 to the intake port 23a (accumulator 24) of the compressor 23 (fourth connection state) so that the refrigerant returns to the compressor 23 (accumulator 24). In addition, the third switching valve 65 connects the third pipe 53 to the intake port 23a (accumulator 24) of the compressor 23 during evacuation work or energy-saving cooling operation (third connection state).

[0059] The outdoor unit 11 of the air conditioning device 10B may have an in-flow path heat exchanger 70. The in-flow path heat exchanger 70 is an example of a heat transfer section. The in-flow path heat exchanger 70 has, for example, a latent heat storage material filled in a block-shaped container. The latent heat storage material is, for example, calcium chloride. The in-flow path heat exchanger 70 may have another latent heat storage material. The in-flow path heat exchanger 70 in the second embodiment is, for example, a heat storage material that can be used in a temperature range of about 10°C to about 100°C.

[0060] The intra-flow heat exchanger 70 is thermally connected to the sixth region 53a of the third pipe 53 between the second expansion valve 64 and the third switching valve 65. Furthermore, the intra-flow heat exchanger 70 is thermally connected to the fourth region 52b of the second pipe 52 between the outdoor heat exchanger 21 and the first expansion valve 31. For example, the sixth region 53a of the third pipe 53 and the fourth region 52b of the second pipe 52 are separated from each other and pass through the intra-flow heat exchanger 70. Therefore, the intra-flow heat exchanger 70 thermally connects the sixth region 53a of the third pipe 53 and the fourth region 52b of the second pipe 52 to each other.

[0061] The intra-flow passage heat exchanger 70 has a larger heat storage capacity than each of the sixth region 53a of the third pipe 53 and the fourth region 52b of the second pipe 52. The fourth region 52b of the second pipe 52 and the sixth region 53a of the third pipe 53 are made of metal and are in close contact with the latent heat storage material of the intra-flow passage heat exchanger 70. For this reason, heat conduction is likely to occur between the sixth region 53a of the third pipe 53 and the fourth region 52b of the second pipe 52 and the latent heat storage material of the intra-flow passage heat exchanger 70.

[0062] In the case of the air conditioner 10B, during energy saving cooling operation, etc., the refrigerant flowing through the third region 52a is controlled to be supercooled by throttling the first expansion valve 31. Then, in the in-flow heat exchanger 70, the refrigerant is further condensed by exchanging heat with the in-flow heat exchanger 70 cooled by the lower temperature refrigerant flowing through the sixth region 53a, and the refrigerant is further condensed to promote liquefaction of the gas-liquid two-phase state. Then, more liquid refrigerant is sent to the indoor heat exchanger 41 side. As a result, more liquid refrigerant can be supplied to the indoor heat exchanger 41 operating as an evaporator during energy saving cooling operation, and heat exchange is performed more efficiently, thereby realizing efficient cooling operation. Also, even if the outdoor air temperature is high and the refrigerant cannot be sufficiently liquefied in the outdoor heat exchanger 21, the liquefaction of the refrigerant is compensated for in the in-flow heat exchanger 70. Therefore, it becomes easier to perform the desired cooling operation without increasing the output of the compressor 23.

[0063] The indoor heat exchanger 41 of the indoor unit 12 absorbs heat as an evaporator or releases heat as a condenser depending on the direction of refrigerant flow. The indoor blower fan 42 blows air toward the indoor heat exchanger 41 to promote heat exchange between the indoor heat exchanger 41 and the air. In other words, the indoor blower fan 42 generates an airflow that exchanges heat with the indoor heat exchanger 41.

[0064] The control device 14 includes, for example, an outdoor control device 14a and an indoor control device 14b. The outdoor control device 14a and the indoor control device 14b are electrically connected to each other by electrical wiring. At least one of the outdoor control device 14a and the indoor control device 14b is, for example, a computer having a control device such as a CPU (Central Processing Unit) or a microcontroller, and a storage device such as a ROM (Read Only Memory), a RAM (Random Access Memory), and a flash memory. Note that the control device 14 is not limited to this example. For example, the control device 14 may include only one of the outdoor control device 14a and the indoor control device 14b.

[0065] The outdoor control device 14a controls the outdoor blower fan 22, the compressor 23, the four-way valve 25, the first expansion valve 31, the second switching valve 61, and the second expansion valve 64 of the outdoor unit 11. The indoor control device 14b controls the indoor blower fan 42 of the indoor unit 12.

[0066] The air conditioner 10B performs cooling operation, heating operation, dehumidification operation, defrosting operation, and other operations by the control device 14 controlling the outdoor unit 11 and the indoor unit 12. The indoor control device 14b may receive signals, for example, from a remote controller, or may receive signals from an information terminal such as a smartphone via a communication device.

[0067] In the case of the air conditioner 10B, similarly to the air conditioner 10A, the refrigerant pipe 13 of the outdoor unit 11 is filled with refrigerant when shipped from the factory, but the refrigerant pipe 13 and the third pipe 53 of the indoor unit 12 are not filled with refrigerant. In other words, similarly to the air conditioner 10A, work is required to discharge air and the like from the refrigerant pipe 13 of the indoor unit 12 and the like (vacuum work to substantially create a vacuum state). In the case of the air conditioner 10B of the second embodiment, the compressor 23 used during normal operation mounted on the outdoor unit 11 is used to substantially create a vacuum state in the refrigerant pipe 13 of the indoor unit 12 and the third pipe 53 of the outdoor unit 11. The procedure for installing the air conditioner 10B will be described below.

[0068] First, the outdoor unit 11 is installed at a predetermined position outdoors. At the time of shipment from the factory, the first switching valve 34 is connected to the atmosphere opening portion 35, and the atmosphere opening portion 35 is in a closed state. The four-way valve 25 is in the same state as during cooling operation, for example. That is, the four-way valve 25 is in a state in which the discharge port 23b of the compressor 23 and the outdoor heat exchanger 21 can be connected via the first switching valve 34. The four-way valve 25 is in a state in which the second switching valve 61 and the third switching valve 65 are connected. The second switching valve 61 is in a state in which the first opening / closing valve 33 and the solenoid valve 62 are connected, that is, the indoor heat exchanger 41 is connected to the third pipe 53 (the sixth region 53a). At this time, the solenoid valve 62 and the second expansion valve 64 are in a closed state. Further, the third switching valve 65 is in a state of connecting the third pipe 53 (the seventh region 53b) and the suction port 23a of the compressor 23 (the accumulator 24).

[0069] In this state, the second piping 52 (fourth region 52b, fifth region 52c) connecting the first on-off valve 33 and the outdoor heat exchanger 21, and the first piping 51 connecting the outdoor heat exchanger 21 and the first switching valve 34 are filled with refrigerant. Then, the first on-off valve 33 and the second on-off valve 32 are maintained in a closed state, and the refrigerant filled in the outdoor unit 11 is maintained in a sealed state.

[0070] The indoor unit 12 is installed at a predetermined position in the room. Then, the first region 51a of the first pipe 51 of the indoor heat exchanger 41 of the indoor unit 12 is connected to the first on-off valve 33 of the outdoor unit 11. Similarly, the third region 52a of the second pipe 52 of the indoor heat exchanger 41 is connected to the second on-off valve 32 of the outdoor unit 11.

[0071] Next, the first on-off valve 33, the solenoid valve 62, the second expansion valve 64, and the atmospheric open section 35 are switched to an open state. When the compressor 23 is operated in this state, the third area 52a of the second pipe 52, the indoor heat exchanger 41, the first area 51a of the first pipe 51, the third pipe 53, and the gas such as air, moisture, dust, etc. present in the installation vacuum area from the third switching valve 65 to the accumulator 24 (the suction port 23a of the compressor 23) in the first pipe 51 are sucked by the compressor 23 and discharged from the atmospheric open section 35. This discharge operation is continued for a predetermined period (a vacuuming time determined in advance by a test, etc.) until the installation vacuum area reaches a predetermined state (a substantial vacuum state: for example, 100 KPa). In the example of FIG. 2, a low pressure sensor 71 is provided between the accumulator 24 and the third switching valve 65.

[0072] The low pressure sensor 71 can automatically stop the compressor 23 when the pressure in the vacuum region at the time of installation reaches a vacuum level equal to or higher than a predetermined level (for example, 100 KPa). The first switching valve 34 can also be automatically switched to connect the four-way valve 25 to the suction port 23a of the compressor 23. When the low pressure sensor 71 detects that the vacuum level has reached a predetermined level, the operator may be notified of this by an alarm sound, a flashing lamp, or the like. At this time, the atmosphere release section 35 is closed manually or automatically.

[0073] In this state, the second on-off valve 32 is opened. As a result, the refrigerant that was filled in the outdoor unit 11 flows into the initial vacuum region where a substantial vacuum state is created by the operation of the compressor 23. That is, the refrigerant is filled into the third region 52a of the second piping 52 of the indoor unit 12, the indoor heat exchanger 41, the first region 51a of the first piping 51, and the third piping 53 of the outdoor unit 11. As a result, the refrigerant is filled into the refrigerant piping 13 through which the refrigerant circulates during normal operation.

[0074] In this way, by switching the first on-off valve 33, the second on-off valve 32, the first switching valve 34, and the atmosphere release section 35 on-off valve, it is possible to substantially evacuate the installation vacuum area including the refrigerant pipe 13 of the indoor unit 12 and the third pipe 53 of the outdoor unit 11 using the compressor 23 installed in the outdoor unit 11 for normal operation. As a result, the installation work of the air conditioner 10B (outdoor unit 11, indoor unit 12) can be easily and quickly performed. In addition, it is possible to perform the above-mentioned evacuation work by simply using the compressor provided in the conventional air conditioner as it is and adding the first switching valve 34 and the atmosphere release section 35 downstream of the discharge port 23b of the compressor 23. As a result, it is possible to contribute to suppressing a significant increase in the product cost of the air conditioner 10B and suppressing a significant design change of the air conditioner 10B.

[0075] Incidentally, the air conditioner 10B configured as described above can perform energy-saving cooling operation when the outdoor air temperature is high, using the third pipe 53 used to evacuate the vacuum region at the time of installation. First, a case where the air conditioner 10B is normally operated when the outdoor air temperature is below a predetermined value will be described. FIG. 3 is an exemplary and schematic diagram showing the flow of refrigerant when the air conditioner 10B performs normal cooling operation when the outdoor air temperature is below a predetermined value (for example, 35°C). As shown in FIG. 3, the indoor heat exchanger 41 is provided with a first temperature sensor 81 and a second temperature sensor 82. The first temperature sensor 81 is a temperature sensor that detects the temperature of the refrigerant flowing through the first region 51a (the temperature at the outlet side of the indoor heat exchanger 41 during cooling operation). The second temperature sensor 82 is a temperature sensor that is provided in the indoor heat exchanger 41 and detects the temperature (intermediate temperature) of the refrigerant flowing through the indoor heat exchanger 41. Further, the in-path heat exchanger 70 of the outdoor unit 11 is provided with a third temperature sensor 83. The third temperature sensor 83 is a temperature sensor that detects an intermediate temperature (internal temperature) of the in-path heat exchanger 70. Note that the outdoor control device 14a is capable of calculating a converted temperature that converts the pressure value output from the low pressure sensor 71 into a temperature. Note that, instead of calculating the converted temperature, a temperature sensor may be disposed near the low pressure sensor 71, and the detected value may be used for control.

[0076] During cooling operation, when the outdoor air temperature (temperature of the outdoor unit 11) is, for example, less than a predetermined value (35°C) and the set temperature of the indoor unit 12 and the intake air temperature are less than 1°C, the second switching valve 61 is switched to connect to the four-way valve 25. In this case, since the air conditioner 10B is in the cooling operation mode, as shown in FIG. 3, the first switching valve 34 is switched to connect the discharge port 23b of the compressor 23 to the four-way valve 25. In addition, the control device 14 (outdoor control device 14a) controls the switching of the four-way valve 25 to connect the discharge port 23b of the compressor 23 to the outdoor heat exchanger 21. Furthermore, the control device 14 (outdoor control device 14a) controls the switching of the second switching valve 61 to connect the indoor heat exchanger 41 to the four-way valve 25.

[0077] In this control state, when the difference between the outdoor air temperature and the set temperature is small, the refrigerant can be liquefied enough to evaporate and absorb heat in the indoor heat exchanger 41 by heat exchange in the outdoor heat exchanger 21. Therefore, the control device 14 (outdoor control device 14a) controls the opening degree of the first expansion valve 31 so that the difference (superheat degree) between the converted temperature based on the pressure value detected by the low pressure sensor 71 and the temperature of the refrigerant flowing through the indoor heat exchanger 41 detected by the second temperature sensor 82 becomes about -2°C, and the refrigerant flows from the outdoor heat exchanger 21 to the indoor heat exchanger 41, where it is vaporized and absorbs heat. Thereafter, the vaporized refrigerant flows through the four-way valve 25 and the second region 51b of the first pipe 51, returns to the accumulator 24, is compressed by the compressor 23, and is supplied to the outdoor heat exchanger 21. This cycle is repeated. In other words, a cooling operation in a low load state is performed.

[0078] On the other hand, FIG. 4 is an illustrative schematic diagram showing the flow of refrigerant when the air conditioning apparatus 10B performs energy-saving cooling operation when the outside air temperature is equal to or higher than a predetermined value (for example, 35° C.) and load operation is forced upon the air conditioning apparatus 10B.

[0079] During cooling operation, when the outdoor air temperature (temperature of the outdoor unit 11) is, for example, a predetermined value (35°C) or higher and the set temperature of the indoor unit 12 and the intake air temperature are 1°C or higher, the second switching valve 61 is switched to connect to the third pipe 53. In this case, the air conditioner 10B is also in the cooling operation mode, so that the first switching valve 34 is switched to connect the discharge port 23b of the compressor 23 and the four-way valve 25 as shown in FIG. 4. In addition, the control device 14 (outdoor control device 14a) controls the switching of the four-way valve 25 to connect the discharge port 23b of the compressor 23 and the outdoor heat exchanger 21. On the other hand, the control device 14 (outdoor control device 14a) controls the switching of the second switching valve 61 to connect the indoor heat exchanger 41 and the third pipe 53.

[0080] As described above, when the outdoor air temperature is high and the outdoor heat exchanger 21 cannot liquefy the refrigerant sufficiently, the heat exchange efficiency in the indoor heat exchanger 41 decreases, so it is necessary to increase the output of the compressor 23 to promote liquefaction in the outdoor heat exchanger 21, but this is undesirable as it leads to an increase in power consumption. Therefore, in the case of the air conditioner 10B, when the difference between the outdoor air temperature and the set temperature is large, the indoor unit 12 does not completely liquefy the refrigerant, but flows it to the sixth region 53a of the third pipe 53 and flows the liquid refrigerant to the in-flow heat exchanger 70. Then, the refrigerant is heat exchanged with the refrigerant flowing from the outdoor heat exchanger 21 through the fourth region 52b of the second pipe 52, and is gasified here. Also, the high-pressure gaseous refrigerant flowing through the fourth region 52b is liquefied here. At this time, the control device 14 (outdoor control device 14a) controls the opening degree of the first expansion valve 31 so that the difference between the converted temperature of the low pressure sensor 71 and the temperature of the first temperature sensor 81 (superheat degree on the indoor unit 12 side) becomes, for example, -1°C. In addition, the control device 14 (outdoor control device 14a) controls the opening degree of the second expansion valve 64 so that the difference between the converted temperature of the low pressure sensor 71 and the temperature of the third temperature sensor 83 (superheat degree of the return of the compressor 23) becomes, for example, 2°C. As a result, even if the refrigerant cannot be sufficiently liquefied in the outdoor heat exchanger 21, the liquefaction of the refrigerant is compensated for in the flow path heat exchanger 70. Therefore, it becomes easier to perform the desired cooling operation without increasing the output of the compressor 23.

[0081] Incidentally, when the air conditioner 10B is operated in a dehumidifying mode, the air volume of the indoor blower fan 42 is reduced, the evaporation temperature is lowered, and the amount of condensed water is secured, so that reliable dehumidification can be performed. Since the air volume of the indoor blower fan 42 is reduced, it is possible to prevent the room in which the indoor unit 12 is installed from becoming excessively cold. On the other hand, there are cases where the refrigerant is not sufficiently gasified in the indoor unit 12. In this case as well, the second switching valve 61 is controlled so that the indoor heat exchanger 41 and the third pipe 53 are connected, and the refrigerant is made to flow into the third pipe 53 and pass through the in-flow heat exchanger 70, so that heat exchange occurs between the refrigerant flowing through the sixth region 53a of the third pipe 53 and the refrigerant flowing through the fourth region 52b of the second pipe 52 coming from the outdoor unit 11, and the refrigerant is gasified. At this time, the high-pressure gaseous refrigerant flowing through the fourth region 52b is liquefied. In this case, the control device 14 (outdoor control device 14a) also controls the opening degree of the first expansion valve 31 so that the difference between the converted temperature of the low pressure sensor 71 and the temperature of the first temperature sensor 81 (the degree of superheat on the indoor unit 12 side) becomes, for example, -1°C. The control device 14 (outdoor control device 14a) also controls the opening degree of the second expansion valve 64 so that the difference between the converted temperature of the low pressure sensor 71 and the temperature of the third temperature sensor 83 (the degree of superheat on the return of the compressor 23) becomes, for example, 2°C. As a result, even if the indoor heat exchanger 41 cannot sufficiently gasify the refrigerant, the gasification of the refrigerant is supplemented in the in-path heat exchanger 70. Therefore, the optimal circulation of the refrigerant can be performed while performing the dehumidification operation. In the second embodiment, any other heat exchange structure may be arranged at the position where the in-path heat exchanger 70 is arranged, as long as heat exchange is possible between the refrigerant passing through the second pipe 52 and the refrigerant passing through the third pipe 53 and the state of the refrigerant can be changed (a liquid refrigerant can be gasified, and a gas refrigerant can be liquefied). For example, instead of the in-path heat exchanger 70, a double pipe in which the second pipe 52 and the third pipe 53 form a spiral double structure may be arranged, and the same effect can be obtained.

[0082] In this way, energy-saving cooling operation and dehumidification operation can be effectively performed even in the air conditioner 10B which is equipped with a configuration for performing a vacuum operation at the time of installation.

[0083] The air conditioning device 10A according to the embodiment described above includes the indoor heat exchanger 41, the outdoor heat exchanger 21, the first pipe 51, the second pipe 52, the compressor 23, the four-way valve 25, the first on-off valve 33, the second on-off valve 32, the first expansion valve 31, the first switching valve 34, and the atmosphere opening unit 35. The first pipe 51 connects the indoor heat exchanger 41 and the outdoor heat exchanger 21, and the refrigerant flows through it. The second pipe connects the outdoor heat exchanger 21 and the indoor heat exchanger 41, and the refrigerant flows through it. The compressor 23 is provided in the first pipe 51 and has an intake port 23a that draws in the refrigerant and an exhaust port 23b that discharges the refrigerant. The four-way valve 25 is provided in the first pipe 51 and can change the direction in which the refrigerant flows. The first on-off valve 33 can close the first pipe connected to the indoor heat exchanger 41. The second on-off valve 32 can close the second pipe 52 connected to the indoor heat exchanger 41. The first expansion valve 31 is provided in the second pipe 52 between the second on-off valve 32 and the outdoor heat exchanger 21. The first on-off valve 33 is provided in the first pipe 51 between the discharge port 23b and the four-way valve 25, and switches between a first switching flow path connecting the discharge port 23b to the four-way valve 25 and a second switching flow path different from the first switching flow path. The atmosphere opening unit 35 opens the second switching flow path to the atmosphere. According to this configuration, when connecting the indoor unit 12 and the outdoor unit 11, it is possible to easily perform vacuum drawing of the refrigerant pipe 13 of the indoor unit 12 while suppressing design changes of existing parts.

[0084] The air conditioner 10B may further include, for example, a third pipe 53 connected to the first pipe 51 between the four-way valve 25 and the first on-off valve 33 and the suction port 23a, a second switching valve 61 provided at one end of the third pipe 53 and switching between a first connection state connecting the first on-off valve 33 and the third pipe 53 and a second connection state connecting the first on-off valve 33 and the four-way valve 25, and a third switching valve 65 provided at the other end of the third pipe 53 and switching between a third connection state connecting the suction port 23a and the third pipe 53 and a fourth connection state connecting the suction port 23a and the four-way valve 25. With this configuration, when connecting the indoor unit 12 and the outdoor unit 11, it is possible to easily perform evacuation of the refrigerant pipe 13 of the indoor unit 12 while suppressing design changes to existing parts. In addition, it is possible to improve the efficiency of energy-saving cooling operation and dehumidification operation.

[0085] Furthermore, the first pipe 51 of the air conditioner 10B may include, for example, a pressure detection unit (low pressure sensor 71) that detects the pressure of the suction port 23a. With this configuration, the refrigerant pipe 13 of the indoor unit 12 can be evacuated stably, reliably, and easily.

[0086] Furthermore, the air conditioning apparatus 10B may further include, for example, a second expansion valve 64 provided between the second switching valve 61 and the third switching valve 65 of the third piping 53, and an in-path heat exchanger 70 provided between the second expansion valve 64 and the third switching valve 65. With this configuration, when connecting the indoor unit 12 and the outdoor unit 11, it is possible to easily evacuate the refrigerant piping 13 of the indoor unit 12 while suppressing design changes to existing parts, and it is possible to further improve the efficiency of energy-saving cooling operation and dehumidification operation.

[0087] Furthermore, the third piping 53 of the air conditioning apparatus 10B may include, for example, a solenoid valve 62 between the second switching valve 61 and the third switching valve 65. This configuration can improve the airtightness retention quality of the refrigerant filled in the outdoor unit 11 at the time of shipment from the factory.

[0088] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0089] Reference Signs List 10A, 10B... air conditioner, 11... outdoor unit, 12... indoor unit, 13... refrigerant piping, 14... control device, 21... outdoor heat exchanger, 23... compressor, 23a... suction port, 23b... discharge port, 24... accumulator, 25... four-way valve, 31... first expansion valve, 32... second on-off valve, 33... first on-off valve, 34... first switching valve, 35... atmospheric release section, 41... indoor heat exchanger, 51... first piping, 51a... first region, 51b... Second region, 52...second piping, 52a...third region, 52b...fourth region, 52c...fifth region, 53...third piping, 53a...sixth region, 53b...seventh region, 61...second switching valve, 62...solenoid valve, 63...filter dryer, 64...second expansion valve, 65...third switching valve, 70...in-path heat exchanger, 71...low pressure sensor, 81...first temperature sensor, 82...second temperature sensor, 83...third temperature sensor.

Claims

1. An indoor heat exchanger; An outdoor heat exchanger; a first pipe connecting the indoor heat exchanger and the outdoor heat exchanger and through which a refrigerant flows; a second pipe connecting the outdoor heat exchanger and the indoor heat exchanger and through which the refrigerant flows; a compressor provided in the first pipe, the compressor having a suction port for sucking the refrigerant and a discharge port for discharging the refrigerant; a four-way valve provided in the first pipe and capable of changing a direction in which the refrigerant flows; a first on-off valve capable of closing the first pipe connected to the indoor heat exchanger; a second on-off valve capable of closing the second pipe connected to the indoor heat exchanger; a first switching valve that is provided in the first pipe between the discharge port and the four-way valve and that switches between a first switching flow path that connects the discharge port to the four-way valve and a second switching flow path that is different from the first switching flow path; an atmosphere opening portion that opens the second switching flow path to the atmosphere; a third pipe connected to the first pipe between the four-way valve and the first on-off valve and to the suction port; a second switching valve that is provided at one end of the third pipe and switches between a first connection state in which the first on-off valve and the third pipe are connected and a second connection state in which the first on-off valve and the four-way valve are connected; a third switching valve provided at the other end of the third pipe and configured to switch between a third connection state in which the suction port and the third pipe are connected and a fourth connection state in which the suction port and the four-way valve are connected; An air conditioning device comprising:

2. The air conditioning apparatus according to claim 1 , wherein the first pipe is provided with a pressure detector that detects a pressure at the suction port.

3. a first expansion valve provided in the second pipe between the second on-off valve and the outdoor heat exchanger; a second expansion valve provided between the second switching valve and the third switching valve of the third pipe; an in-path heat exchanger provided between the second expansion valve and the third switching valve; The air conditioning apparatus according to claim 1 or 2, further comprising:

4. The air-conditioning apparatus according to claim 1 , wherein the third pipe includes a solenoid valve between the second switching valve and the third switching valve.

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