JP7633925B2 - Air Conditioning Equipment - Google Patents

Description

An embodiment of the present invention relates to an air conditioning device.

Air conditioners, such as air conditioners, regulate the indoor temperature by condensing and evaporating the refrigerant in the refrigeration cycle. Generally, the outdoor unit is filled with refrigerant at a factory or the like during manufacturing and transported to the installation site of the air conditioner in a sealed state. Meanwhile, the indoor unit is transported to the installation site without being filled with refrigerant (with air, volatile gases, and 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 with the gas removed from the refrigerant piping of the indoor unit. As a result, the refrigerant that was filled in the outdoor unit moves to the indoor unit, 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.

JP 2007-71421 A

However, the task of bringing a vacuum pump to the installation site each time increases installation costs and reduces the efficiency of the installation work. In addition, when performing vacuum drawing using the compressor disclosed in Patent Document 1, a general compressor cannot be used, which raises the risk of increased product costs.

One example of the problem that the present invention solves is to provide an air conditioner that can easily evacuate the medium piping of the indoor unit while minimizing the need to change the design of existing parts when connecting the indoor unit and outdoor unit.

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 change-over valve, an atmospheric release unit, a third pipe, a second change-over valve, and a third change-over valve . The first pipe connects the indoor heat exchanger and the outdoor heat exchanger, and a refrigerant flows through it. The second pipe connects the outdoor heat exchanger and the indoor heat exchanger, and the refrigerant flows through it. The compressor is provided in the first pipe and has an intake port that draws in the refrigerant and an outlet port that discharges 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 on-off valve is capable of closing the first pipe connected to the indoor heat exchanger. The second on-off 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 discharge port and the four-way valve, and switches between a first switching flow path connecting the discharge port to the four-way valve and a second switching flow path different from the first switching flow path. An 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. The second switching valve is provided at one end of the third pipe, and switches between a first connection state connecting the first on-off valve and the third pipe and a second connection state connecting the first on-off valve and the four-way valve. The third switching valve is provided at the other end of the third pipe, and switches between a third connection state connecting the suction port and the third pipe and a fourth connection state connecting the suction port and the four-way valve.

The first pipe of the air conditioning device may also be equipped with, for example, a pressure detection unit that detects the pressure at the intake port.

The air conditioning device may also 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 the third switching valve, and an in-flow path heat exchanger provided between the second expansion valve and the third switching valve.

The third piping of the air conditioning device may also include, for example, a solenoid valve between the second switching valve and the third switching valve.

The above air conditioning device can provide an air conditioning device that can easily evacuate the medium piping of the indoor unit while minimizing the need to change the design of existing components when connecting the indoor unit and outdoor unit, for example.

FIG. 1 is an exemplary schematic diagram showing a refrigerant system of an air-conditioning apparatus according to a first embodiment. FIG. 2 is an exemplary schematic diagram showing another refrigerant system diagram of the air conditioner according to the second embodiment. 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. 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.

Below, several embodiments are described with reference to Figs. 1 to 4. Note that in this specification, components according to the embodiments and descriptions of the components may be described in multiple ways. The components and their descriptions are merely examples and are not limited by the expressions in this specification. The components may also be identified by names different from those in this specification. The components may also be described by expressions different from those in this specification.

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 installation vacuum region of the refrigerant piping 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.

As shown in FIG. 1, the air conditioning device 10A has an outdoor unit 11, an indoor unit 12, refrigerant piping 13, and a control device 14. The outdoor unit 11 is placed, for example, outdoors. The indoor unit 12 is placed, for example, indoors.

The air conditioning device 10A has a refrigeration cycle in which an outdoor unit 11 and an indoor unit 12 are connected by refrigerant piping 13. 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, for example, by electrical wiring.

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 atmospheric release section 35. The indoor unit 12 has an indoor heat exchanger 41 and an indoor blower fan 42.

The refrigerant piping 13 is a pipe made of a metal such as copper or aluminum. The refrigerant piping 13 has a first piping 51 and a second piping 52. The first piping 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 atmospheric release section 35 are provided in the first piping 51. The second piping 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 piping 52.

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

The outdoor heat exchanger 21 of the outdoor unit 11 acts as an evaporator to absorb heat from the refrigerant or as a condenser to release heat from the refrigerant depending on the direction of refrigerant flow. The outdoor blower fan 22 blows air toward the outdoor heat exchanger 21, promoting 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.

The compressor 23 has an intake port 23a and an exhaust port 23b. The compressor 23 draws in the refrigerant from the intake port 23a and exhausts the compressed refrigerant from the exhaust port 23b. In this way, the compressor 23 compresses the refrigerant in the refrigeration cycle and causes the refrigerant to circulate.

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.

The first switching valve 34 is connected to the discharge port 23b of the compressor 23, the four-way valve 25, and the atmospheric release 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 when installing the air conditioning device 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 atmospheric release section 35, switches to the second switching flow path, and releases unnecessary gas that exists in the refrigerant piping 13 of the indoor unit 12 and the outdoor unit 11 during normal operation of the air conditioning device 10A to the atmosphere during installation work. The atmosphere release section 35 can be configured, for example, as a manual on-off valve that is opened when unnecessary gas is released to the atmosphere and closed otherwise. Basically, the atmosphere release section 35 is not used after the installation work of the air conditioning device 10A is completed. Therefore, when the installation work is completed, the atmosphere release section 35 may be 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.

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 during heating operation and cooling operation, changing the direction in which the refrigerant flows.

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.

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 to the indoor heat exchanger 41 via the first switching valve 34. 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.

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.

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, for example, at a factory or the like, when the outdoor unit 11 is manufactured and the first pipe 51 and the second pipe 52 of the outdoor unit 11 are filled with refrigerant. Then, as described below, when the air conditioning device 10A is installed (when the outdoor unit 11 and the indoor unit 12 are installed), the first on-off valve 33 and the second on-off valve 32 are selectively opened and closed to degas (vacuum) the pipe 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.

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, promoting 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.

The control device 14 has, 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, a ROM (Read Only Memory), a RAM (Random Access Memory), and a storage device such as a flash memory. Note that the control device 14 is not limited to this example. For example, the control device 14 may have only one of the outdoor control device 14a and the indoor control device 14b.

The outdoor control device 14a controls the outdoor blower fan 22, compressor 23, four-way valve 25, and 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.

The control device 14 controls the outdoor unit 11 and the indoor unit 12, so that the air conditioning device 10A performs cooling operation, heating operation, dehumidification operation, defrosting operation, and other operations. 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.

As mentioned 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, it is necessary to discharge gas such as air from the refrigerant pipe 13 of the indoor unit 12 (vacuuming work to essentially create a vacuum state). Then, after the vacuuming work is completed, it is necessary to connect the refrigerant pipe 13 of the indoor unit 12 to the refrigerant pipe 13 of the outdoor unit 11, and fill the indoor unit 12 with the refrigerant filled on the outdoor unit 11 side. Conventionally, when the refrigerant pipes 13 of the indoor unit 12 are substantially evacuated, a vacuum pump or the like is connected, but in the case of the air conditioner 10A of this embodiment, the compressor 23 used during normal operation mounted on the outdoor unit 11 is used to substantially evacuate the refrigerant pipes 13 of the indoor unit 12. The procedure for installing the air conditioner 10A is described below.

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 release section 35, and the atmospheric release 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 also 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.

The indoor unit 12 is installed at a predetermined position in the room. Then, a first area 51a, which is a part of the first pipe 51 of the indoor heat exchanger 41 of the indoor unit 12, is connected to the first opening and closing valve 33 of the outdoor unit 11. Similarly, a third area 52a, which is a part of the second pipe 52 of the indoor heat exchanger 41, is connected to the second opening and closing valve 32 of the outdoor unit 11.

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

After a predetermined period of time has elapsed, or after a sensor (not shown) detects that the vacuum area at installation has reached a predetermined state, the atmospheric release section 35 is closed. Simultaneously with or after this closing, 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 opening/closing valve 32 is opened. As a result, the refrigerant that had been filled in the outdoor unit 11 flows into the vacuum area at installation 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.

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 atmospheric release section 35 on-off valve, 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 conditioning device 10A (outdoor unit 11, indoor unit 12) can be easily and quickly performed. In addition, it is possible to perform the above-mentioned vacuum work by simply using the compressor 23 provided in the conventional air conditioning device as it is and adding the first switching valve 34 and the atmospheric 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 conditioning device 10A and suppressing a significant design change of the air conditioning device 10A.

Second Embodiment
2 is a refrigerant system diagram of an air conditioning device 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 conditioning device 10B is installed. The air conditioning device 10B is also, for example, a home air conditioner. Note that the air conditioning device 10B is not limited to this example, and may be other air conditioning devices 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 conditioning device 10A described in the first embodiment.

As shown in FIG. 2, the air conditioning device 10B also has an outdoor unit 11, an indoor unit 12, refrigerant piping 13, and a control device 14. The outdoor unit 11 is placed, for example, outdoors. The indoor unit 12 is placed, for example, indoors.

The air conditioning device 10B has a refrigeration cycle in which an outdoor unit 11 and an indoor unit 12 are connected by refrigerant piping 13. 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, for example, by electrical wiring.

The outdoor unit 11 of the air conditioning device 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 release section 35, similar to the outdoor unit 11 of the air conditioning device 10A. The outdoor unit 11 of the air conditioning device 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.

The refrigerant piping 13 is a pipe made of a metal such as copper or aluminum. The refrigerant piping 13 has a first piping 51, a second piping 52, and a third piping 53. The first piping 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 release section 35 are provided in the second region 51b of the first piping 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 opening/closing valve 32, and connects the outdoor heat exchanger 21 and the indoor heat exchanger 41. The first expansion valve 31 and the second opening/closing 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 pipe 53 is a pipe that can be used when performing the vacuum operation of the refrigerant pipe 13 of the indoor unit 12 described in the air conditioning device 10A. The second switching valve 61, the solenoid valve 62, the filter dryer 63, the second expansion valve 64, and the third switching valve 65 are provided in the third pipe 53. The third pipe 53 can also be used when performing energy saving operation or dehumidification operation of the air conditioning device 10B when the outside air temperature is high (e.g., 35°C or higher). Details regarding the vacuum operation and energy saving cooling operation using the third pipe 53 will be described later.

In cooling operation, the refrigerant flows from the indoor heat exchanger 41 to the outdoor heat exchanger 21 through the first pipe 51, and flows from the outdoor heat exchanger 21 to the indoor heat exchanger 41 through the second pipe 52. In heating operation, the refrigerant flows from the outdoor heat exchanger 21 to the indoor heat exchanger 41 through the first pipe 51, and flows from the indoor heat exchanger 41 to the outdoor heat exchanger 21 through the second pipe 52. The arrows in FIG. 2 indicate the flow of gases to be exhausted when evacuating the vacuum area when installing the refrigerant pipes, as described below.

The outdoor heat exchanger 21 of the outdoor unit 11 acts as an evaporator to absorb heat from the refrigerant or as a condenser to release heat from the refrigerant depending on the direction of refrigerant flow. The outdoor blower fan 22 blows air toward the outdoor heat exchanger 21, promoting 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.

The compressor 23 has an intake port 23a and an exhaust port 23b. The compressor 23 draws in the refrigerant from the intake port 23a and exhausts the compressed refrigerant from the exhaust port 23b. In this way, the compressor 23 compresses the refrigerant in the refrigeration cycle and causes the refrigerant to circulate.

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.

The first switching valve 34 is connected to the discharge port 23b of the compressor 23, the four-way valve 25, and the atmospheric release 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 when installing the air conditioning device 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 atmospheric release section 35, switches to the second switching flow path, and releases unnecessary gas that exists in the refrigerant piping 13 of the indoor unit 12 and the outdoor unit 11 during normal operation of the air conditioning device 10B to the atmosphere during installation work. The atmosphere release section 35 can be configured, for example, as a manual on-off valve that is opened when unnecessary gas is released to the atmosphere and closed otherwise. Basically, the atmosphere release 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 release section 35 is fixed in a closed state. Similarly, the first switching valve 34 may be fixed in a state that connects the discharge port 23b and the four-way valve 25 when the installation work is completed.

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) via the third switching 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 switching valve 65 during heating operation and cooling operation, thereby changing the direction in which the refrigerant flows.

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 through 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 through the second switching valve 61 to the accumulator 24 through 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) during 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.

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 to the indoor heat exchanger 41 via the first switching valve 34. 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.

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.

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, for example, at a factory or the like when the outdoor unit 11 is manufactured and the like, in a state in which the first pipe 51 and the second pipe 52 of the outdoor unit 11 are filled with refrigerant. Then, as described below, when the air conditioning device 10B is installed (when the outdoor unit 11 and the indoor unit 12 are installed), the first on-off valve 33 and the second on-off valve 32 are selectively opened and closed to degas (vacuum) the pipe 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.

The second switching valve 61 connects the indoor heat exchanger 41 to the third pipe 53 when performing vacuum work on the refrigerant pipe 13 of the indoor unit 12 during installation work of the air conditioning device 10B, and when performing energy-saving cooling operation or the like when the outdoor air temperature is a predetermined temperature (e.g., 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 a 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.

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 pipe 53. As described above, the third pipe 53 is used when performing the vacuuming work when the air conditioning device 10B is installed. Therefore, the third pipe 53 is not filled with refrigerant when shipped from the factory. Instead, in order to prevent deterioration of the third pipe 53, such as corrosion, an inert gas (e.g., nitrogen gas) may be filled. The solenoid valve 62 ensures the retention of the inert gas. Note that if sufficient closure of the third pipe 53 can be ensured by closing the first opening/closing valve 33, the solenoid valve 62 may be omitted.

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

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 vacuum operation.

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 so that the refrigerant returns to the compressor 23 (accumulator 24) (fourth connection state). In addition, the third switching valve 65 connects the third pipe 53 to the intake port 23a (accumulator 24) of the compressor 23 during vacuuming work or energy-saving cooling operation (third connection state).

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 other latent heat storage materials. 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.

The in-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 in-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 in-flow heat exchanger 70. Therefore, the in-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.

The heat exchanger 70 in the flow passage has a larger heat storage capacity than the sixth region 53a of the third pipe 53 and the fourth region 52b of the second pipe 52. In addition, 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 heat exchanger 70 in the flow passage. 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 heat exchanger 70 in the flow passage.

In the case of the air conditioning device 10B, during energy-saving cooling operation, 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 into a gas-liquid two-phase state. Then, more liquid refrigerant is sent to the indoor heat exchanger 41. As a result, more liquid refrigerant can be supplied to the indoor heat exchanger 41, which operates as an evaporator during energy-saving cooling operation, and heat exchange is performed more efficiently, thereby achieving 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.

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, promoting 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.

The control device 14 has, 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, a ROM (Read Only Memory), a RAM (Random Access Memory), and a storage device such as a flash memory. Note that the control device 14 is not limited to this example. For example, the control device 14 may have only one of the outdoor control device 14a and the indoor control device 14b.

The outdoor control device 14a controls the outdoor blower fan 22, compressor 23, four-way valve 25, first expansion valve 31, second switching valve 61, and 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.

The control device 14 controls the outdoor unit 11 and the indoor unit 12, so that the air conditioning device 10B performs cooling operation, heating operation, dehumidification operation, defrosting operation, and other operations. 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.

In the case of the air conditioning device 10B, as in the air conditioning device 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, as in the air conditioning device 10A, work is required to exhaust air, etc. from the refrigerant pipe 13 of the indoor unit 12, etc. (vacuum work to create a substantially vacuum state). In the case of the air conditioning device 10B of the second embodiment, the compressor 23 used during normal operation mounted on the outdoor unit 11 is used to create a substantially 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 conditioning device 10B is described below.

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 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 piping 53 (sixth region 53a). At this time, the solenoid valve 62 and the second expansion valve 64 are in a closed state. Additionally, the third switching valve 65 is in a state where it connects the third pipe 53 (seventh region 53b) to the suction port 23a (accumulator 24) of the compressor 23.

In this state, the second pipe 52 (fourth area 52b, fifth area 52c) connecting the first on-off valve 33 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 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.

The indoor unit 12 is installed at a predetermined position in the room. Then, the first area 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 area 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.

Next, the first opening/closing valve 33, the solenoid valve 62, the second expansion valve 64, and the atmospheric release 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) of the first pipe 51 are sucked by the compressor 23 and discharged from the atmospheric release 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 area reaches a predetermined state (a substantial vacuum state: for example, 100 KPa). In the case of the example of FIG. 2, a low pressure sensor 71 is provided between the accumulator 24 and the third switching valve 65.

The low pressure sensor 71 can automatically stop the compressor 23 when the pressure in the vacuum area at the time of installation reaches a predetermined vacuum level (e.g., 100 KPa) or higher. The first switching valve 34 can also be automatically switched to connect the four-way valve 25 to the intake 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 by an alarm sound or a flashing lamp, for example. At this time, the atmospheric release section 35 is closed manually or automatically.

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 installation vacuum area where a substantial vacuum state is created by the operation of the compressor 23. In other words, the refrigerant is filled into the third area 52a of the second pipe 52 of the indoor unit 12, the indoor heat exchanger 41, the first area 51a of the first pipe 51, and the third pipe 53 of the outdoor unit 11. As a result, the refrigerant is filled into the refrigerant pipe 13 through which the refrigerant circulates during normal operation.

In this way, by switching the first on-off valve 33, the second on-off valve 32, the first switching valve 34, and the atmospheric release section 35 on-off valve, it is possible to substantially evacuate the installation vacuum area including the refrigerant piping 13 of the indoor unit 12 and the third piping 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 conditioning device 10B (outdoor unit 11, indoor unit 12) can be easily and quickly performed. In addition, it is possible to perform the above-mentioned vacuum work by simply using the compressor provided in the conventional air conditioning device as it is and adding the first switching valve 34 and the atmospheric 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 conditioning device 10B and suppressing a significant design change of the air conditioning device 10B.

By the way, the air conditioning device 10B configured as described above can perform energy-saving cooling operation when the outdoor air temperature is high by using the third pipe 53 used to evacuate the vacuum area at the time of installation. First, a case where the air conditioning device 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 the refrigerant when the air conditioning device 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 area 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. In addition, a third temperature sensor 83 is provided in the in-flow heat exchanger 70 of the outdoor unit 11. The third temperature sensor 83 is a temperature sensor that detects the intermediate temperature (internal temperature) of the in-flow heat exchanger 70. 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. Instead of calculating the converted temperature, a temperature sensor may be placed near the low pressure sensor 71 and the detected value may be used for control.

During cooling operation, when the outdoor air temperature (temperature of the outdoor unit 11) is, for example, below a predetermined value (35°C) and the set temperature of the indoor unit 12 and the intake air temperature are below 1°C, the second switching valve 61 is switched to connect to the four-way valve 25. In this case, since the air conditioning device 10B is in 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.

In this control state, when the difference between the outdoor air temperature and the set temperature is small, the refrigerant can be liquefied sufficiently 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 is 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. The vaporized refrigerant then 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 under low load is performed.

On the other hand, FIG. 4 is an exemplary schematic diagram showing the flow of refrigerant when the air conditioning device 10B is performing energy-saving cooling operation when the outside air temperature is equal to or higher than a predetermined value (e.g., 35°C) and the device is forced to operate under load.

During cooling operation, when the outdoor air temperature (temperature of the outdoor unit 11) is, for example, above a predetermined value (35°C) and the set temperature of the indoor unit 12 and the intake air temperature are above 1°C, the second switching valve 61 is switched to connect to the third pipe 53. In this case, the air conditioning device 10B is also in cooling operation mode, so as shown in FIG. 4, 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. 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 to the third pipe 53.

As mentioned above, when the outdoor air temperature is high and sufficient liquefaction cannot be achieved in the outdoor heat exchanger 21, 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 conditioning device 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 gasified here. In addition, 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) is, 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 (superheat degree on the compressor 23 return) is, 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.

By the way, when the air conditioning device 10B is operated in dehumidification 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, the second switching valve 61 is controlled so that the indoor heat exchanger 41 and the third pipe 53 are connected, and the refrigerant flows into the third pipe 53 and passes 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) is, 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) is, 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 compensated for in the flow path heat exchanger 70. Therefore, the optimal circulation of the refrigerant can be performed while performing the dehumidification operation. In the second embodiment, 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 at the position where the in-flow heat exchanger 70 is arranged, and the state of the refrigerant can be changed (gasification of liquid refrigerant, liquefaction of gas refrigerant), other heat exchange structures may be arranged. For example, instead of the in-flow 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.

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

The air conditioning device 10A according to the embodiment described above includes an indoor heat exchanger 41, an outdoor heat exchanger 21, a first pipe 51, a second pipe 52, a compressor 23, a four-way valve 25, a first on-off valve 33, a second on-off valve 32, a first expansion valve 31, a first switching valve 34, and an atmospheric release section 35. The first pipe 51 connects the indoor heat exchanger 41 and the outdoor heat exchanger 21, and a refrigerant flows through it. The second pipe connects the outdoor heat exchanger 21 and the indoor heat exchanger 41, and a refrigerant flows through it. The compressor 23 is provided in the first pipe 51 and has an intake port 23a for sucking in the refrigerant and an exhaust port 23b for discharging 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. With this configuration, when connecting the indoor unit 12 and the outdoor unit 11, it is possible to easily vacuum the refrigerant pipe 13 of the indoor unit 12 while suppressing design changes to existing parts.

The air conditioning device 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, the refrigerant pipe 13 of the indoor unit 12 can be easily vacuumed while suppressing design changes to existing parts. In addition, the efficiency of energy-saving cooling operation and dehumidification operation can be improved.

The first pipe 51 of the air conditioning device 10B may also be equipped with, for example, a pressure detection unit (low pressure sensor 71) that detects the pressure at the intake port 23a. With this configuration, the refrigerant pipe 13 of the indoor unit 12 can be evacuated stably, reliably, and easily.

The air conditioning device 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-flow 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 the efficiency of energy-saving cooling operation and dehumidification operation can be further improved.

The third pipe 53 of the air conditioning device 10B may also 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 of the refrigerant filled in the outdoor unit 11 at the time of shipment from the factory.

Although several 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 embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the scope of the invention and its equivalents described in the claims.

10A, 10B... air conditioning device, 11... outdoor unit, 12... indoor unit, 13... refrigerant piping, 14... control device, 21... outdoor heat exchanger, 23... compressor, 23a... intake 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 area, 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...internal heat exchanger, 71...low pressure sensor, 81...first temperature sensor, 82...second temperature sensor, 83...third temperature sensor.

Claims (4)

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: 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. 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: 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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