WO2012063289A1

WO2012063289A1 - Refrigeration cycle device and cooling medium filling method

Info

Publication number: WO2012063289A1
Application number: PCT/JP2010/006614
Authority: WO
Inventors: 裕之森本; 山下　浩司; 傑鳩村
Original assignee: 三菱電機株式会社
Priority date: 2010-11-11
Filing date: 2010-11-11
Publication date: 2012-05-18

Abstract

Provided are a refrigeration cycle device and a cooling medium filling method with which carbon dioxide, a cooling medium having a low global warming potential, or the like can be safely filled. One end of an opening/closing device (207) is connected to a cooling medium pipe connecting a pipe (400b) and a flow path switching device (203), and the other end is connected via a connecting pipe (209)to a cooling medium cylinder (208) filled with a cooling medium.

Description

Refrigeration cycle apparatus and refrigerant charging method

The present invention relates to a refrigeration cycle apparatus and a refrigerant charging method applied to, for example, a building multi-air conditioner.

Conventionally, in an air conditioner such as a building multi-air conditioner, for example, a refrigerant is circulated between an outdoor unit that is a heat source unit arranged outdoors and an indoor unit arranged in a building interior, and the refrigerant radiates heat, and The air-conditioning space is cooled or heated with air that has absorbed heat and has been heated or cooled. In such a building multi-air conditioner, a plurality of indoor units are connected, and there are many cases where a stopped indoor unit and an operating indoor unit are mixed. In addition, the pipe connecting the outdoor unit and the indoor unit may be up to 100 m, and the longer the pipe, the more refrigerant must be filled into the system.

In home air conditioners (room air conditioners), the outdoor unit is filled with the refrigerant necessary for the system, so there is no need to refill the refrigerant locally. On the other hand, in a building multi-air conditioner, since the amount of refrigerant is very large, it is not possible to enclose all the refrigerant in the outdoor unit, so it is necessary to charge the refrigerant locally. Thus, by additionally filling the refrigerant locally, the amount of the refrigerant can be properly maintained, and the system performance can be maximized.

By the way, in recent years, from the viewpoint of global warming, there is a situation in which the use of HFC refrigerants having a high global warming potential (for example, R410A, R404A, R407C, and R134a) is limited, and refrigerants having a low global warming potential (for example, , Carbon dioxide, etc.) have been proposed. At this time, even when carbon dioxide is used as a refrigerant in a building multi-air conditioner, on-site refrigerant charging is required in the same manner as conventionally used refrigerants.

Japanese Patent Laid-Open No. 2001-91112 (paragraph 0006 etc. of the specification)

In Patent Document 1, the valve of the outdoor unit is opened at the time of construction, the refrigerant in the outdoor unit flows into the connection pipe and the indoor unit, and the refrigerant charge port provided in the valve of the other outdoor unit, or the connection port of the valve The operation of substituting the refrigerant with the gas in the indoor unit and the connecting pipe is carried out by releasing the refrigerant containing air from the gap portion formed by relaxing the connection.

Even when carbon dioxide is used as a refrigerant in an air conditioner, the refrigerant must be charged locally as described above. Carbon dioxide has an extremely high refrigerant pressure as compared with the conventional refrigerant (R410A), and is about 6.4 MPa at room temperature (25 ° C.). In such a high pressure state, a method of purging air from a gap portion formed by relaxing the connection of the connection port at the time of filling the refrigerant, a large amount of carbon dioxide is ejected from the gap portion, or the refrigerant filling hose is disconnected from the connection port. There is a problem that there is a risk that it is dangerous.

In addition, since HFO1234yf, R290, R32, etc., which are refrigerants with a low global warming potential, are flammable, work is performed in the method of purging air from gaps that are formed by relaxing the connection of the connection ports when filling the refrigerant. Since the refrigerant leaks to the surrounding area, there is still a problem that it involves danger.

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a refrigeration cycle apparatus and a refrigerant charging method that can safely fill carbon dioxide or a refrigerant having a low global warming potential.

A refrigeration cycle apparatus according to the present invention includes a heat source side unit including a compressor and a heat source side heat exchanger, a usage side unit including a usage side heat exchanger, a throttle device that depressurizes the refrigerant, and the refrigerant circulates. The valve body through which the flow path is penetrated is connected to a refrigerant cylinder or the like by a connecting pipe, and an intake port through which the refrigerant is drawn from the refrigerant cylinder or the like, and the refrigerant drawn from the refrigerant cylinder or the like through the intake port An opening / closing device having a supply port that flows out and a purge port that discharges the refrigerant supplied from the refrigerant cylinder together with the air in the connection pipe, and at least the compressor, the heat source side heat exchange The refrigeration cycle circuit in which the refrigerant, the expansion device, and the use side heat exchanger are connected by the refrigerant pipe to circulate the refrigerant, and the supply port is connected to the refrigerant pipe in the refrigeration cycle circuit, The valve body is in a communication state in which the suction port and the supply port communicate with each other by switching the flow path so that the refrigerant can be sealed in the refrigeration cycle circuit from the refrigerant cylinder or the like. And the purge port communicate with each other, a purge state in which the refrigerant supplied from the refrigerant cylinder or the like together with the air in the connection pipe can be discharged from the purge port, and the suction port, the supply port, and the Any of the three states of the closed state in which none of the purge ports communicate can be switched, and the refrigerant operates in a supercritical state in at least a part of the circulation path of the refrigeration cycle circuit.

According to the present invention, a refrigerant such as carbon dioxide having a high operating pressure or a refrigerant having a low global warming potential can be safely filled in the refrigeration cycle circuit.

It is a figure which shows an example of the circuit structure of the air conditioning apparatus 100 which concerns on Embodiment 1 of this invention. It is a refrigerant circuit diagram which shows the flow of the refrigerant | coolant at the time of the air_conditioning | cooling operation mode of the air conditioning apparatus 100 which concerns on Embodiment 1 of this invention. It is a refrigerant circuit diagram which shows the flow of the refrigerant | coolant at the time of the heating operation mode of the air conditioning apparatus 100 which concerns on Embodiment 1 of this invention. It is a figure explaining the refrigerant | coolant filling operation | movement to the air conditioning apparatus 100 which concerns on Embodiment 1 of this invention. It is a structural diagram of the opening / closing device 207 of the air-conditioning apparatus 100 according to Embodiment 1 of the present invention. It is a figure which shows another form of the circuit structure of the air conditioning apparatus 100 which concerns on Embodiment 1 of this invention. It is a structural diagram of another form of the switching device 207 of the air-conditioning apparatus 100 according to Embodiment 1 of the present invention. It is the schematic which shows the example of installation of the air conditioning apparatus 101 which concerns on Embodiment 2 of this invention. It is an outline figure showing an example of circuit composition of air harmony device 101 concerning Embodiment 2 of the present invention. It is a refrigerant circuit figure which shows the flow of the refrigerant | coolant at the time of the cooling only operation mode of the air conditioning apparatus 101 which concerns on Embodiment 2 of this invention. It is a refrigerant circuit diagram which shows the flow of the refrigerant | coolant at the time of the heating only operation mode of the air conditioning apparatus 101 which concerns on Embodiment 2 of this invention. It is a refrigerant circuit diagram which shows the flow of the refrigerant | coolant at the time of the cooling main operation mode of the air conditioning apparatus 101 which concerns on Embodiment 2 of this invention. It is a refrigerant circuit diagram which shows the flow of the refrigerant | coolant at the time of heating main operation mode of the air conditioning apparatus 101 which concerns on Embodiment 2 of this invention.

Embodiment 1 FIG.
(Configuration of the air conditioner 100)
1 is a diagram illustrating an example of a circuit configuration of an air-conditioning apparatus 100 according to Embodiment 1 of the present invention. Hereinafter, the circuit configuration of the air-conditioning apparatus 100 will be described with reference to FIG. FIG. 1 shows an example in which four indoor units 300 are connected. In addition, in the following drawings including FIG. 1, the relationship between the sizes of the constituent members is not limited to that illustrated, and may be different from the actual one. Moreover, in this Embodiment, although the air conditioning apparatus 100 is demonstrated to an example as a refrigerating cycle apparatus, it is not limited to this, A refrigerator, a heat pump water heater, and other refrigerating cycle apparatuses may be sufficient.

As shown in FIG. 1, in the air conditioner 100, an outdoor unit 200 on the heat source side and an indoor unit 300 on the usage side are connected by a pipe 400. Among the pipes 400, a pipe connected to the expansion device 302 described later of the indoor unit 300 is referred to as a pipe 400a, and a pipe connected to a use side heat exchanger 301 described later of the indoor unit 300 is referred to as a pipe 400b. By this pipe 400, the refrigerant is circulated between the outdoor unit 200 and the indoor unit 300. It is assumed that carbon dioxide (CO 2) is enclosed as a refrigerant in the refrigeration cycle circuit configured in the air conditioner 100.

The outdoor unit 200 and the indoor unit 300 correspond to the “heat source side unit” and the “use side unit” of the present invention, respectively.

(Configuration of outdoor unit 200)
As shown in FIG. 1, the outdoor unit 200 includes an accumulator 205, a compressor 201, an oil separator 202, a flow switching device 203 that is a four-way valve, and a heat source side heat exchanger 204 in order by refrigerant piping. Connected and configured. The suction side of the compressor 201 and the inflow side of the oil separator 202 are connected by an oil return capillary 206. In addition, on the low-pressure gas piping side of the outdoor unit 200, an opening / closing device 207, which is a service valve for filling a refrigerant or drawing a vacuum, is provided. In FIG. 1, an opening / closing device 207 is provided in the refrigerant pipe that connects the pipe 400 b and the flow path switching device 203.

The compressor 201 sucks and compresses the gas refrigerant to be brought into a high temperature and high pressure state and transports it to the refrigeration cycle circuit. For example, the compressor 201 may be composed of an inverter compressor capable of controlling capacity.

The oil separator 202 is provided on the discharge side of the compressor 201 and separates the refrigerant from the refrigeration oil.

The flow path switching device 203 is provided on the downstream side of the oil separator 202, and switches between a refrigerant flow in the heating operation mode and a refrigerant flow in the cooling operation mode.

The heat source side heat exchanger 204 functions as an evaporator in the heating operation mode, functions as a radiator (gas cooler) in the cooling operation mode, and is supplied with air and refrigerant supplied from a blower (not shown) such as a fan. Heat exchange is performed between the two, and the refrigerant is evaporated or condensed.

The accumulator 205 is provided on the suction side of the compressor 201, and surplus refrigerant due to the difference between the heating operation mode and the cooling operation mode, or a transient operation change (for example, the number of indoor units 300 operated). The surplus refrigerant is stored against

The oil return capillary 206 returns the refrigeration oil captured by the oil separator 202 to the suction side of the compressor 201.

The opening / closing device 207 is a service valve for filling the refrigeration cycle circuit with a refrigerant or drawing a vacuum.

(Configuration of indoor unit 300)
As shown in FIG. 1, the indoor unit 300 is composed of four units, which are referred to as an indoor unit 300a, an indoor unit 300b, an indoor unit 300c, and an indoor unit 300d from the left side of FIG. In the case shown, it is simply referred to as the indoor unit 300. These indoor units 300a to 300d are connected in parallel as shown in FIG. The indoor unit 300 is configured by connecting a use side heat exchanger 301 and an expansion device 302 in series by a refrigerant pipe. Here, the four usage-side heat exchangers 301 shown in FIG. 1 are divided into a usage-side heat exchanger 301a, a usage-side heat exchanger 301b, a usage-side heat exchanger 301c, according to the indoor units 300a to 300d. And it shall be called the utilization side heat exchanger 301d, and when it shows without distinction, it shall be only called the utilization side heat exchanger 301. Further, the four diaphragm devices 302 shown in FIG. 1 are referred to as a diaphragm device 302a, a diaphragm device 302b, a diaphragm device 302c, and a diaphragm device 302d in accordance with the indoor units 300a to 300d, which are shown without distinction. In this case, the diaphragm device 302 is simply referred to.

The use-side heat exchanger 301 functions as a radiator (gas cooler) in the heating operation mode, functions as an evaporator in the cooling operation mode, and is supplied with air and refrigerant supplied from a fan (not shown) such as a fan. Heat exchange is performed between the two, and heating air or cooling air for supplying to the air-conditioning target space is generated.

The expansion device 302 has a function as a pressure reducing valve or an expansion valve, expands the refrigerant by depressurizing it, and can be configured by a device whose opening degree can be variably controlled, for example, an electronic expansion valve. .

As shown in FIG. 1, the indoor unit 300 is configured as four units, and accordingly, the use side heat exchanger 301 and the expansion device 302 are also configured as four units, but the number is limited to these numbers. It is not something.

(Cooling operation mode)
FIG. 2 is a refrigerant circuit diagram illustrating a refrigerant flow when the air-conditioning apparatus 100 according to Embodiment 1 of the present invention is in the cooling operation mode. In FIG. 2, the case where all of the indoor units 300 are driven will be described as an example. In FIG. 2, the flow direction of the refrigerant is indicated by an arrow.

First, in the cooling operation mode, the control device (not shown) sends the refrigerant discharged from the compressor 201 and passing through the oil separator 202 to the flow path switching device 203 of the outdoor unit 200 as the heat source side heat exchanger 204. The refrigerant flow path is switched so as to flow into.

A low-temperature and low-pressure gas refrigerant is compressed by the compressor 201 and discharged as a high-temperature and high-pressure gas refrigerant. Here, since the refrigerant is carbon dioxide, it becomes a gas refrigerant in a supercritical state. The high-temperature and high-pressure gas refrigerant discharged from the compressor 201 flows into the oil separator 202. Refrigerating machine oil mixed with the gas refrigerant is separated from the gas refrigerant flowing into the oil separator 202. The refrigerating machine oil separated from the gas refrigerant by the oil separator 202 is returned to the discharge side of the compressor 201 via the oil return capillary 206. The gas refrigerant separated by the oil separator 202 flows into the heat source side heat exchanger 204 via the flow path switching device 203. The gas refrigerant flowing into the heat source side heat exchanger 204 is heat-exchanged with the outside air supplied from a blower (not shown), and radiates heat to the outdoor air. At this time, since the refrigerant is carbon dioxide, the high-temperature and high-pressure gas refrigerant that has flowed into the heat source-side heat exchanger 204 flows out of the heat source-side heat exchanger 204 in a supercritical state in a temperature-decreasing state. The supercritical low-temperature and high-pressure refrigerant flowing out of the heat source side heat exchanger 204 flows out of the outdoor unit 200 by flowing out of the pipe 400a.

The low-temperature and high-pressure refrigerant that has flowed out of the outdoor unit 200 flows into the indoor unit 300 (the indoor unit 300a to the indoor unit 300d), and flows into the expansion device 302 (the expansion device 302a to the expansion device 302d). The refrigerant flowing into the expansion device 302 is expanded and depressurized to become a low-temperature and low-pressure gas-liquid two-phase refrigerant. The low-temperature and low-pressure gas-liquid two-phase refrigerant flowing out from the expansion device 302 flows into the use side heat exchanger 301 (use side heat exchanger 301a to use side heat exchanger 301d). The gas-liquid two-phase refrigerant that has flowed into the use side heat exchanger 301 is subjected to heat exchange with room air supplied from a blower (not shown) to cool the room air. At this time, the gas-liquid two-phase refrigerant absorbs heat from the indoor air, and thus flows out of the use-side heat exchanger 301 as a low-temperature and low-pressure gas refrigerant. The low-temperature and low-pressure gas refrigerant that has flowed out of the use side heat exchanger 301 flows out of the indoor unit 300 by flowing out of the pipe 400b.

Here, a temperature sensor is usually installed at the refrigerant outlet and outlet of the use side heat exchanger 301, and the amount of refrigerant supplied to the use side heat exchanger 301 is based on temperature information from these temperature sensors. Have been adjusted. Specifically, the control device calculates the degree of superheat (refrigerant temperature at the outflow side−refrigerant temperature at the inlet) based on the temperature information from these temperature sensors, and the degree of superheat is about 2 to 5 ° C. Thus, the opening degree of the expansion device 302 is determined, and the refrigerant supply amount to the use side heat exchanger 301 is adjusted.

The low-temperature and low-pressure gas refrigerant that has flowed out of the indoor unit 300 flows into the outdoor unit 200 again, and flows into the accumulator 205 through the flow path switching device 203. The gas refrigerant flowing into the accumulator 205 is separated from the liquid refrigerant mixed in the gas refrigerant. The gas refrigerant flowing out from the accumulator 205 is sucked into the compressor 201 and compressed again.

In such a cooling operation mode, since the superheat degree control is performed in each indoor unit 300, the liquid refrigerant basically does not flow into the accumulator 205. However, in a transitional state or when there is a stopped indoor unit 300, a small amount of liquid refrigerant (dryness of about 0.95) may flow into the accumulator 205. The liquid refrigerant flowing into the accumulator 205 is evaporated and sucked into the compressor 201, or sucked into the compressor 201 through an oil return hole (not shown) provided in the outlet pipe of the accumulator 205. .

(Heating operation mode)
FIG. 3 is a refrigerant circuit diagram illustrating a refrigerant flow when the air-conditioning apparatus 100 according to Embodiment 1 of the present invention is in the heating operation mode. In FIG. 3, a case where all of the indoor units 300 are driven will be described as an example. In addition, in FIG. 3, the flow direction of a refrigerant | coolant is shown by the arrow.

First, in the heating operation mode, the control device (not shown) causes the flow path switching device 203 of the outdoor unit 200 to discharge the refrigerant discharged from the compressor 201 and passing through the oil separator 202 to the indoor unit 300. Thus, the refrigerant flow path is switched.

A low-temperature and low-pressure gas refrigerant is compressed by the compressor 201 and discharged as a high-temperature and high-pressure gas refrigerant. Here, since the refrigerant is carbon dioxide, it becomes a gas refrigerant in a supercritical state. The high-temperature and high-pressure gas refrigerant discharged from the compressor 201 flows into the oil separator 202. Refrigerating machine oil mixed with the gas refrigerant is separated from the gas refrigerant flowing into the oil separator 202. The refrigerating machine oil separated from the gas refrigerant by the oil separator 202 is returned to the discharge side of the compressor 201 via the oil return capillary 206. Further, the gas refrigerant separated by the oil separator 202 flows out of the outdoor unit 200 by flowing out to the pipe 400b via the flow path switching device 203.

The high-temperature and high-pressure gas refrigerant that has flowed out of the outdoor unit 200 flows into the indoor unit 300 (the indoor unit 300a to the indoor unit 300d) and is used on the use side heat exchanger 301 (the use side heat exchanger 301a to the use side heat exchanger 301d). Flow into. The gas refrigerant that has flowed into the use-side heat exchanger 301 undergoes heat exchange with room air supplied from a blower (not shown), and radiates heat to the room air. At this time, since the refrigerant is carbon dioxide, the high-temperature and high-pressure gas refrigerant that has flowed into the use-side heat exchanger 301 flows out of the use-side heat exchanger 301 in a supercritical state in a temperature-decreasing state. The supercritical low-temperature and high-pressure refrigerant that has flowed out of the use-side heat exchanger 301 flows into the expansion device 302 (the expansion device 302a to the expansion device 302d). The refrigerant flowing into the expansion device 302 is expanded and depressurized to become a low-temperature and low-pressure gas-liquid two-phase refrigerant. The low-temperature and low-pressure gas-liquid two-phase refrigerant that has flowed out of the expansion device 302 flows out of the indoor unit 300 by flowing out of the pipe 400a.

Here, a temperature sensor and a pressure sensor are usually installed at the refrigerant outlet of the use side heat exchanger 301, and the amount of refrigerant supplied to the use side heat exchanger 301 is temperature information from the temperature sensor. And adjustment based on pressure information from the pressure sensor. Specifically, the control device uses the temperature information from the temperature sensor and the pressure information from the pressure sensor to determine the degree of supercooling (the saturation temperature converted from the detected pressure of the refrigerant on the outflow side minus the refrigerant on the outflow side). The temperature of the expansion device 302 is determined so that the degree of supercooling is about 2 to 5 ° C., and the amount of refrigerant supplied to the use-side heat exchanger 301 is adjusted.

The low-temperature and low-pressure gas-liquid two-phase refrigerant that has flowed out of the indoor unit 300 flows into the outdoor unit 200 again and flows into the heat source side heat exchanger 204. The gas-liquid two-phase refrigerant that has flowed into the heat source side heat exchanger 204 is subjected to heat exchange with outside air supplied from a blower (not shown). At this time, the gas-liquid two-phase refrigerant absorbs heat from the outside air and becomes a gas-liquid two-phase refrigerant having a large dryness and flows out from the heat source side heat exchanger 204. The gas-liquid two-phase refrigerant that has flowed out of the heat source side heat exchanger 204 flows into the accumulator 205 via the flow path switching device 203. The gas-liquid two-phase refrigerant that has flowed into the accumulator 205 is separated from the liquid refrigerant mixed in the gas refrigerant. The separated gas refrigerant flows out of the accumulator 205, is sucked into the compressor 201, and is compressed again.

(Refrigerant charging operation to the air conditioner 100)
FIG. 4 is a diagram for explaining the refrigerant charging operation to the air-conditioning apparatus 100 according to Embodiment 1 of the present invention, and FIG. 5 is a structural diagram of the opening / closing device 207 of the air-conditioning apparatus 100. Hereinafter, the refrigerant | coolant filling operation | movement to the air conditioning apparatus 100 is demonstrated, referring FIG.4 and FIG.5.

4 shows that the other end (P side shown in FIG. 5) of the opening / closing device 207 in which one end (Q side shown in FIG. 5) is connected to the refrigerant pipe connecting the pipe 400b and the flow path switching device 203, The figure connected to the refrigerant cylinder 208 filled with the refrigerant | coolant via the connection pipe 209 is shown. Here, it is assumed that the refrigeration cycle circuit in the air conditioner 100 shown in FIG. 4 is in a state where a vacuum is drawn by a vacuum pump, and after the evacuation is completed, the switchgear 207 and the refrigerant cylinder 208 are connected. Connect by tube 209. When connecting the connecting pipe 209 to the opening / closing device 207, the opening / closing device 207 is kept in the closed state shown in FIG.

Next, the structure of the opening / closing device 207 will be described with reference to FIG. 5. As shown in FIG. 5 (a), the opening / closing device 207 is composed of at least a valve body 207a and four sealing materials 207b. ing. The opening / closing device 207 is a so-called ball valve, and has a flow path 207c that penetrates the ball-shaped valve body 207a. By switching the direction of the

flow path

207c, 3 described later It is possible to switch to one flow path state, that is, a communication state, a purge state, and a closed state. The switching operation of the flow path state of the opening / closing device 207 may be performed manually by a serviceman with respect to the opening / closing device 207, or by operating an external remote control device or the like, The flow path state may be switched to the opening / closing device 207 with respect to (not shown). In order to enhance the sealing function of the opening / closing device 207, the sealing material 207b may be formed of a material such as Teflon (registered trademark).

It is also assumed that the P side of the opening / closing device 207 is connected to the connecting pipe 209, and the Q side of the opening / closing device 207 is connected to the refrigerant pipe connecting the pipe 400b and the flow path switching device 203.

As shown in FIG. 5A, by switching the direction of the flow path 207c of the valve body 207a so as to communicate with the P-side flow path and the Q-side flow path, the P-side is changed to the Q-side direction. A communication channel is formed, and the refrigerant flows from the P side to the Q side. Hereinafter, the state of the opening / closing device 207 is referred to as a communication state.

As shown in FIG. 5B, the direction of the flow path 207c of the valve body 207a is switched from the P side to the R side so as to communicate with the P side flow path and the R side flow path. A communicating flow is formed, and the refrigerant flows from the P side to the R side. Hereinafter, the state of the opening / closing device 207 is referred to as a purge state. Further, since the R side of the on-off valve 207 is intended to purge the refrigerant, the flow rate of the circulating refrigerant may be reduced by reducing the flow path diameter than the P side and the Q side, for example, The channel diameter may be about 5 mm or less.

As shown in FIG. 5C, by rotating the flow path 207c of the opening / closing device 207 by 90 ° from the communication position, the flow path 207c does not communicate with any flow path, and the refrigerant opens and closes. The device 207 cannot be conducted. Hereinafter, the state chamber of the opening / closing device 207 is referred to as a closed state.

The P side, Q side, and R side of the opening / closing device 207 correspond to the “suction port”, “supply port”, and “purge port” of the present invention, respectively.

When the service person fills the refrigerant in the refrigeration cycle circuit of the air conditioner 100, first, the opening / closing device 207 is closed. Next, the service person connects the refrigerant cylinder 208 to the opening / closing device 207 through the connection pipe 209, and then opens the valve of the refrigerant cylinder 208. Then, the service person switches the opening / closing device 207 to the purge state shown in FIG. In this purge state, the refrigerant flowing out from the refrigerant cylinder 208 flows through the connection pipe 209, flows into the inside from the P side of the opening / closing device 207, and is discharged from the R side through the valve body 207a. The At this time, the air remaining in the connecting pipe 209 is discharged from the R side, and only the refrigerant exists in the connecting pipe 209. After sufficient air is discharged together with the refrigerant from the R side of the opening / closing device 207, the service person once brings the opening / closing device 207 into a communication state and encloses an appropriate amount of refrigerant in the refrigeration cycle circuit of the air conditioner 100. The service person encloses an appropriate amount of refrigerant in the refrigeration cycle circuit of the air conditioner 100, then closes the opening / closing device 207, and ends the refrigerant charging operation.

(Effect of Embodiment 1)
Unlike the method of purging air by forming a gap portion at the connection portion as in the conventional air conditioner, the air conditioner 100 according to the present embodiment forms a purge state as described above. An openable / closable device 207 is provided in the air conditioner 100. As a result, it is possible to greatly reduce the risk of sudden leakage of refrigerant, disconnection of the connection pipe, and release of a large amount of refrigerant, and it is possible to purge the air in the connection pipe 209 safely. The air conditioning apparatus 100 can be provided. This is particularly effective for carbon dioxide with a high pressure.

As shown in FIG. 6, a charging hose 210 may be attached to the R side of the on-off valve 207. When flammable refrigerants such as HFO1234yf, R32, and R290 are used, there are cases where work handling fire, such as brazing, is being carried out in the vicinity where service personnel are working, and the refrigerant is released. That is dangerous. Therefore, the charging hose 210 is connected to the opening / closing device 207, and the refrigerant is discharged to a fire and a safe place that is not popular. Thus, by connecting the charging hose 210 to the position on the R side of the opening / closing device 207, it is possible to safely perform the refrigerant charging.

The refrigerant is charged into the refrigeration cycle circuit of the air conditioner 100 when the air conditioner 100 is installed or when it is refilled when the refrigerant leaks. Few. Therefore, as shown in FIG. 7, a structure may be adopted in which a plug can be provided on the R side of the opening / closing device 207 with a plug 211 or the like. As described above, by attaching the plug 211 to the opening / closing device 207 during charging of the refrigerant, it is possible to suppress the occurrence of refrigerant leakage during charging of the refrigerant and refrigerant leakage when the opening / closing device 207 is opened by mistake. it can. To release air and refrigerant from the R side in the purge state, the plug 211 may be removed and the above procedure may be performed.

Moreover, although the refrigerant | coolant with which the refrigerating cycle circuit is filled with the switchgear 207 was made into carbon dioxide, it is not limited to this, HFO1234yf, R32, R290, HC system refrigerant | coolant, those mixed refrigerant | coolants, and other refrigerant | coolants are filled. Needless to say, it can be a thing.

Furthermore, as described above, in the present embodiment, the air conditioning apparatus 100 has been described as an example of the refrigeration cycle apparatus. However, the present invention is not limited to this, and may be a refrigeration machine, a heat pump water heater, or other refrigeration cycle apparatuses. Good. In this case, the open / close device 207, which is a service valve for filling the refrigerant or drawing a vacuum, may be provided on the low-pressure gas piping side of the heat source side unit in the refrigeration cycle apparatus as described above. .

Embodiment 2. FIG.
In the air conditioner 100 according to the first embodiment, a method (direct expansion method) in which the refrigerant is used as it is for cooling is adopted. However, in the air conditioner 101 according to the second embodiment, the refrigerant (on the heat source side) is used. A system that indirectly uses (refrigerant) is adopted. That is, the air-conditioning apparatus 101 according to Embodiment 2 transmits the cold or warm heat stored in the heat source-side refrigerant to a heat medium different from the heat source-side refrigerant, and the air-conditioning target space with the cold or hot heat stored in the heat medium. Is to be cooled or heated.

(Configuration of air conditioner 101)
FIG. 8 is a schematic diagram showing an installation example of the air-conditioning apparatus 101 according to Embodiment 2 of the present invention.
In this air conditioner 101, a refrigerant circulation circuit A that is a refrigeration cycle circuit that circulates refrigerant and a heat medium circulation circuit B that is a refrigeration cycle circuit that circulates a heat medium are configured. Alternatively, the cooling operation mode or the heating operation mode can be freely selected as the operation mode for a plurality of indoor units.

As shown in FIG. 8, the air conditioner according to the present embodiment includes a single outdoor unit 1 that is a heat source unit, a plurality of indoor units 2, and an outdoor unit 1 and an indoor unit 2. It has an intermediate heat medium relay 3. The outdoor unit 1 and the heat medium relay unit 3 are connected by a refrigerant pipe 4 through which a refrigerant on the heat source side flows. The heat medium relay unit 3 and the indoor unit 2 are connected by a heat medium pipe 5 through which the heat medium flows. Then, the cold heat or heat generated by the outdoor unit 1 is transmitted to the indoor unit 2 via the heat medium relay unit 3.

The outdoor unit 1 is usually installed in an outdoor space 6 that is a space outside a building 9 such as a building (for example, a rooftop), and supplies cold or hot heat to the indoor unit 2 via the heat medium converter 3. It is.

The indoor unit 2 is installed at a position where cooling air or heating air can be supplied to the indoor space 7 that is an air-conditioning target space (for example, a living room) inside the building 9, and the cooling air or heating is supplied to the indoor space 7. Supply air.

The heat medium relay unit 3 is configured as a separate housing from the outdoor unit 1 and the indoor unit 2 and is configured to be installed at a position different from the outdoor space 6 and the indoor space 7. Are connected by a refrigerant pipe 4 and a heat medium pipe 5, respectively, and transmit cold heat or hot heat supplied from the outdoor unit 1 to the indoor unit 2. Specifically, the heat medium converter 3 includes a heat source side refrigerant on the outdoor unit 1 side and a heat medium (for example, water, brine (antifreeze)), brine and water on the indoor unit 2 side different from the heat source side refrigerant. Or a mixed solution of water and an additive having a high anticorrosion effect). Further, FIG. 8 shows an example in which the heat medium relay unit 3 is installed in a space 8 such as a back of the ceiling, which is inside the building 9 but is different from the indoor space 7. Yes. Moreover, since the heat medium converter 3 is provided close to the indoor unit 2 installed in the indoor space 7, the piping of the heat medium circulation circuit through which the heat medium circulates can be shortened. Thereby, the conveyance power of the heat medium in the heat medium circulation circuit can be reduced, and energy saving can be achieved.

The refrigerant pipe 4 is composed of two, and connects the outdoor unit 1 and the heat medium relay unit 3. Further, the heat medium pipe 5 also connects the heat medium converter 3 and each indoor unit 2, and is connected to each indoor unit 2 by two heat medium pipes 5. Thus, in the air conditioning apparatus according to Embodiment 1, each unit (outdoor unit 1, indoor unit 2, and heat medium converter 3) is configured using two pipes (refrigerant pipe 4 and heat medium pipe 5). ) Is easy to install.

In addition, in FIG. 8, although the example in which the outdoor unit 1 is installed in the outdoor space 6 is shown, it is not limited to this. For example, the outdoor unit 1 may be installed in an enclosed space such as a machine room with a ventilation opening, and if the waste heat can be exhausted outside the building 9 by an exhaust duct, Alternatively, when the water-cooled outdoor unit 1 is used, it may be installed inside the building 9.

8 shows an example in which the indoor unit 2 is a ceiling cassette type. However, the present invention is not limited to this, and the indoor unit 2 is not directly limited to the indoor space 7 such as a ceiling embedded type or a ceiling suspended type. Alternatively, any type of air can be used as long as heating air or cooling air can be blown out by a duct or the like.

Moreover, although the heat medium converter 3 shall be installed in the space 8 as shown in FIG. 8, it is not limited to this, For example, it installs in the common space etc. with an elevator etc. It may be a thing.

Further, as described above, the heat medium relay unit 3 is provided close to the indoor unit 2, but is not limited thereto, and may be installed in the vicinity of the outdoor unit 1. .

And the number of connected outdoor units 1, indoor units 2 and heat medium converters 3 is not limited to the number shown in FIG. 8, but building 9 in which the air conditioner according to Embodiment 1 is installed. The number may be determined according to the situation.

In addition, in the following drawings including FIG. 8, the relationship between the sizes of the constituent members is not limited to that shown in the drawings, and may differ from the actual ones.

In the present embodiment, the air conditioning apparatus 101 is described as an example of the refrigeration cycle apparatus, but the present invention is not limited to this, and a refrigeration machine, a heat pump water heater, or other refrigeration cycle apparatus may be used.

FIG. 9 is an outline diagram illustrating an example of a circuit configuration of the air-conditioning apparatus 101 according to Embodiment 2 of the present invention.
As shown in FIG. 9, the outdoor unit 1 and the heat medium relay unit 3 include a refrigerant circulation circuit in each of the heat exchanger related to heat medium 15 a and the heat exchanger related to heat medium 15 b provided in the heat medium converter 3. Connected by A. Here, the refrigerant circulation circuit A includes the refrigerant pipe 4 that connects the outdoor unit 1 and the heat medium relay 3, and the heat exchanger related to heat medium 15 a and the heat exchanger related to heat medium in the heat medium converter 3. In each of 15b, it refers to a refrigerant circuit configured by connecting each device with a refrigerant pipe through which a refrigerant that performs heat exchange with a heat medium flows. Specifically, the refrigerant circulation circuit A includes a compressor 10, a first refrigerant flow switching device 11, a heat source side heat exchanger 12, a switching device 17, a second refrigerant flow switching device 18, and heat between heat mediums, which will be described later. The refrigerant flow path of the exchanger 15, the expansion device 16, and the accumulator 19 are connected by refrigerant piping. It is assumed that carbon dioxide is enclosed in the refrigerant circuit A as a refrigerant. Details of the connection relation of each of the above devices constituting the refrigerant circuit A will be described later.

Further, the heat medium relay unit 3 and the indoor unit 2 are connected to the heat exchanger related to heat medium 15a and the heat exchanger related to heat medium 15b provided in the heat medium converter 3 by a heat medium circulation circuit B described later. Has been. Here, the heat medium circulation circuit B includes the heat medium pipe 5 that connects the heat medium converter 3 and each indoor unit 2, and includes the heat exchanger 15 a between the heat medium and the heat medium between the heat medium converter 3. It refers to a heat medium circuit configured by connecting each device by a heat medium pipe through which a heat medium that performs heat exchange with a refrigerant flows in each heat exchanger 15b. Specifically, the heat medium circulation circuit B uses a heat medium flow path of the heat exchanger 15 between heat mediums, a pump 21, a first heat medium flow switching device 22, a heat medium flow control device 25, which will be described later. The side heat exchanger 26 and the second heat medium flow switching device 23 are connected by a heat medium pipe. Details of the connection relationship of each of the above devices constituting the heat medium circuit B will be described later.

The outdoor unit 1 and the indoor unit 2 correspond to the “heat source side unit” and the “use side unit” of the present invention, respectively.

Hereinafter, the configurations of the outdoor unit 1, the indoor unit 2, and the heat medium relay unit 3 will be described in detail with reference to FIG.

(Configuration of outdoor unit 1)
The outdoor unit 1 includes a compressor 10, a first refrigerant flow switching device 11, such as a four-way valve, a heat source side heat exchanger 12, and an accumulator 19, which are connected in series by a refrigerant pipe. In addition, on the low-pressure gas piping side of the outdoor unit 1, an opening / closing device 40 that is a service valve for filling a refrigerant or drawing a vacuum is provided. In FIG. 9, an opening / closing device 40 is provided in the refrigerant pipe connecting the refrigerant pipe 4 and the heat source side heat exchanger 12.

The compressor 10 sucks and compresses a gas refrigerant to bring it into a high temperature and high pressure state, and may be composed of, for example, an inverter compressor capable of capacity control.

The first refrigerant flow switching device 11 has a refrigerant flow and a cooling operation mode (in a cooling only operation mode and a cooling main operation mode) in a heating operation mode (in a heating only operation mode and a heating main operation mode, which will be described later). ) To change the refrigerant flow.

The heat source side heat exchanger 12 functions as an evaporator in the heating operation mode, functions as a radiator (gas cooler) in the cooling operation mode, and is supplied with air and refrigerant supplied from a blower (not shown) such as a fan. Heat exchange between the two.

The accumulator 19 is provided on the suction side of the compressor 10, and surplus refrigerant due to a difference between the heating operation mode and the cooling operation mode, or a transient operation change (for example, the number of operating units of the indoor unit 2 is The excessive refrigerant with respect to (change) is stored.

(Configuration of indoor unit 2)
Each indoor unit 2 includes a use side heat exchanger 26. Here, the four indoor units 2 shown in FIG. 2 are referred to as an indoor unit 2a, an indoor unit 2b, an indoor unit 2c, and an indoor unit 2d from the bottom. It shall be 2. In addition, the four usage side heat exchangers 26 shown in FIG. 2 are connected to the usage side heat exchanger 26a, the usage side heat exchanger 26b, and the usage side heat exchanger 26c from below according to the indoor units 2a to 2d. And it will be referred to as a use side heat exchanger 26d, and when referred to without distinction, it is simply referred to as a use side heat exchanger 26.

The use-side heat exchanger 26 passes the heat medium flowing out from the heat medium converter 3 via the second heat medium flow switching device 23, and the heat medium flowing out from the indoor unit 2. The heat medium pipes 5 that are circulated and flow into the heat medium flow control device 25 of the heat medium converter 3 are respectively connected by heat medium pipes. The use side heat exchanger 26 functions as a radiator during heating operation and functions as a heat absorber during cooling operation, and between indoor air supplied from a fan (not shown) such as a fan and a heat medium. Heat exchange is performed to generate heating air or cooling air to be supplied to the indoor space 7.

Note that the number of indoor units 2 is not limited to the four shown in FIG. 9 as in FIG.

(Configuration of heat medium converter 3)
The heat medium relay unit 3 includes two heat exchangers 15 between the heat mediums, two expansion devices 16, two switching devices 17, four second refrigerant flow switching devices 18, two pumps 21, and four first heats. A medium flow switching device 22, four second heat medium flow switching devices 23, and four heat medium flow control devices 25 are provided.

The two intermediate heat exchangers 15 shown in FIG. 9 are referred to as an intermediate heat exchanger 15a and an intermediate heat exchanger 15b, respectively. Assume that the container 15.

In addition, the two diaphragm devices 16 shown in FIG. 9 are referred to as a diaphragm device 16a and a diaphragm device 16b, respectively.

Further, of the four second refrigerant flow switching devices 18 shown in FIG. 9, two second refrigerant flow switching devices 18 connected to the heat exchanger related to heat medium 15a are respectively connected to the second refrigerant flow switching devices 18a. The switching device 18a and the second refrigerant flow switching device 18b are referred to as two second refrigerant flow switching devices 18 connected to the heat exchanger related to heat medium 15b. 18c and the second refrigerant flow switching device 18d, and when these four are shown without distinction, they are simply called the second refrigerant flow switching device 18.

Further, the two pumps 21 shown in FIG. 9 are referred to as a pump 21a and a pump 21b, respectively.

Also, the four first heat medium flow switching devices 22 shown in FIG. 9 are divided into the first heat medium flow switching device 22a and the first heat medium flow switching from the bottom according to the indoor units 2a to 2d. The device 22b, the first heat medium flow switching device 22c, and the first heat medium flow switching device 22d are assumed.

Further, the four second heat medium flow switching devices 23 shown in FIG. 9 are divided into the second heat medium flow switching device 23a and the second heat medium flow switching from the bottom according to the indoor units 2a to 2d. The device 23b, the second heat medium flow switching device 23c, and the second heat medium flow switching device 23d are assumed.

Further, the four heat medium flow control devices 25 shown in FIG. 9 are arranged from the bottom according to the indoor units 2a to 2d, from the bottom, the heat medium flow control device 25a, the heat medium flow control device 25b, and the heat medium flow control device 25c. In addition, the heat medium flow control device 25d is assumed.

The heat exchanger related to heat medium 15 functions as a radiator or an evaporator, performs heat exchange between the refrigerant and the heat medium, generates cold heat or heat generated by the outdoor unit 1 and stored in the refrigerant as a heat medium. To communicate. Among these, the heat exchanger related to heat medium 15a is provided between the expansion device 16a in the refrigerant circuit A and the second refrigerant flow switching device 18a (and the second refrigerant flow switching device 18b). In the heating only operation mode described later, the heating medium is heated, and in the cooling only operation mode, the cooling main operation mode, and the heating main operation mode described later, the heat medium is cooled. The heat exchanger related to heat medium 15b is provided between the expansion device 16b in the refrigerant circuit A and the second refrigerant flow switching device 18c (and the second refrigerant flow switching device 18d). In the cooling only operation mode, the heat medium is cooled. In the heating only operation mode, the cooling main operation mode, and the heating main operation mode, which will be described later, the heat medium is heated.

The expansion device 16 functions as a pressure reducing valve and an expansion valve in the refrigerant circuit A, and decompresses the refrigerant to expand it. Among these, the expansion device 16a is provided on the upstream side of the heat exchanger related to heat medium 15a in the flow of the refrigerant in the cooling operation mode, and is connected to the switchgear 17 by a refrigerant pipe. The expansion device 16b is provided on the downstream side of the heat exchanger related to heat medium 15b in the refrigerant flow in the heating operation mode, and is connected to the opening / closing device 17 by a refrigerant pipe. Further, the expansion device 16 may be configured by a device whose opening degree can be variably controlled, for example, an electronic expansion valve or the like.

The opening / closing device 17 is composed of a two-way valve or the like, and opens and closes the refrigerant piping in the refrigerant circulation circuit A. The opening / closing device 17 is installed in a refrigerant pipe connecting the expansion device 16 a (and the expansion device 16 b) and the refrigerant pipe 4.

The second refrigerant flow switching devices 18a to 18d are constituted by two-way valves or the like, and in the refrigerant circulation circuit A, the refrigerant flow is switched according to the operation mode. Among them, the second refrigerant flow switching device 18a is provided on the downstream side of the heat exchanger related to heat medium 15a in the refrigerant flow in the cooling only operation mode and the cooling main operation mode, which will be described later, and is connected to the refrigerant pipe 4. ing. The second refrigerant flow switching device 18b is provided on the downstream side of the heat exchanger related to heat medium 15a in the refrigerant flow in the heating main operation mode described later, and is connected to the refrigerant pipe 4 via the branch pipe 4d. ing. The second refrigerant flow switching device 18c is provided on the upstream side of the heat exchanger related to heat medium 15b in the refrigerant flow in the heating only operation mode and the heating main operation mode, which will be described later, and is connected to the refrigerant pipe 4. Yes. The second refrigerant flow switching device 18d is provided on the upstream side of the heat exchanger related to heat medium 15b in the refrigerant flow in the cooling main operation mode described later, and is connected to the refrigerant pipe 4 via the branch pipe 4d. ing.

The pump 21 circulates the heat medium in the heat medium circuit B. Among these, the pump 21 a is provided in a heat medium pipe connecting the heat exchanger related to heat medium 15 a and the second heat medium flow switching device 23. The pump 21 b is provided in a heat medium pipe that connects the heat exchanger related to heat medium 15 b and the second heat medium flow switching device 23. Further, the pump 21 may be constituted by a pump whose capacity can be controlled, for example.
The pump 21a may be provided in a heat medium pipe connecting the heat exchanger related to heat medium 15a and the first heat medium flow switching device 22, and the pump 21b is connected to the heat exchanger related to heat medium 15b and the first heat medium flow switch 15b. It is good also as what is provided in the heat medium piping which connects 1 heat medium flow-path switching apparatus 22. FIG.

The first heat medium flow switching device 22 is configured by a three-way valve or the like, and in the heat medium circulation circuit B, switches the flow path of the heat medium according to the operation mode. Further, the number of the first heat medium flow switching devices 22 (four in FIG. 9) according to the number of indoor units 2 installed is provided. The first heat medium flow switching device 22 includes one of the three heat transfer medium heat exchangers 15a, the other heat transfer medium heat exchanger 15b, and the other heat medium flow rate adjustment. Each is connected to the device 25.

The second heat medium flow switching device 23 is constituted by a three-way valve or the like, and in the heat medium circulation circuit B, switches the heat medium flow path according to the operation mode. Further, the number of second heat medium flow switching devices 23 is set according to the number of indoor units 2 installed (four in FIG. 9). Further, the second heat medium flow switching device 23 has one of the three sides to the pump 21a, the other to the pump 21b, and the other one to the heat medium pipe 5 for circulating the heat medium to the indoor unit 2. , Each connected.

The heat medium flow control device 25 is configured by a two-way valve or the like that can control the opening area. To do. In addition, the number of the heat medium flow control devices 25 (four in FIG. 9) according to the number of indoor units 2 installed is provided. In addition, one of the heat medium flow control devices 25 is the heat medium pipe 5 through which the heat medium flowing out from the use side heat exchanger 26 of the indoor unit 2 flows into the heat medium converter 3, and the other is the first heat medium flow path. Each is connected to the switching device 22.
The heat medium flow control device 25 is installed in the heat medium piping system on the outlet side of the heat medium flow path of the use side heat exchanger 26 as described above, but is not limited to this. Heat medium piping system on the inlet side of the side heat exchanger 26 (for example, the second heat medium flow switching device 23 and the heat medium flowing out of the heat medium converter 3 flows into the use side heat exchanger 26 of the indoor unit 2) It is good also as what is installed between the heat-medium piping 5 to be made.

Further, the heat medium relay unit 3 includes two first temperature sensors 31, four second temperature sensors 34, four third temperature sensors 35, and a pressure sensor 36. Information (temperature information and pressure information) detected by these detection devices is transmitted to a control device (not shown) that controls the operation of the air conditioner 101. The control device is constituted by a microcomputer or the like, and based on these information and operation information from a remote controller or the like, the driving frequency of the compressor 10, the rotational speed of the blower (not shown), the first refrigerant flow switching device. 11 and switching of the refrigerant flow path of the second refrigerant flow switching device 18, switching frequency of the pump 21, switching of the heat medium flow path of the first heat medium flow switching device 22 and the second heat medium flow switching device 23, The heat medium flow rate control device 25 controls the heat medium flow rate and the like, and implements various operation modes described later.
The control device may be provided for each indoor unit 2 or may be provided in the outdoor unit 1 or the heat medium relay unit 3.

The four second temperature sensors 34 shown in FIG. 2 are divided into the second temperature sensor 34a, the second temperature sensor 34b, the second temperature sensor 34c, and the second temperature from the bottom according to the indoor units 2a to 2d. The sensor 34d is assumed.

The two first temperature sensors 31 (the first temperature sensor 31a and the first temperature sensor 31b) are the heat medium that has flowed out of the heat exchanger related to heat medium 15, that is, the heat at the heat medium outlet side of the heat exchanger related to heat medium 15. The temperature of the medium is detected, and for example, it may be constituted by a thermistor or the like. Among these, the 1st temperature sensor 31a is provided in the heat carrier piping in the inlet side of the pump 21a. The first temperature sensor 31b is provided in the heat medium pipe on the inlet side of the pump 21b.

The second temperature sensor 34 is provided between the first heat medium flow switching device 22 and the heat medium flow control device 25, and detects the temperature of the heat medium flowing out from the use side heat exchanger 26. For example, what is necessary is just to comprise with a thermistor etc. Further, the number of second temperature sensors 34 (four in FIG. 2) corresponding to the number of indoor units 2 installed is provided.

The third temperature sensor 35a is installed between the heat exchanger related to heat medium 15a and the second refrigerant flow switching device 18a (and the second refrigerant flow switching device 18b), and flows into the heat exchanger related to heat medium 15a. Alternatively, the temperature of the refrigerant flowing out of the heat exchanger related to heat medium 15a is detected. The third temperature sensor 35b is installed between the heat exchanger related to heat medium 15a and the expansion device 16a and flows into the heat exchanger related to heat medium 15a or flows out of the heat exchanger related to heat medium 15a. The refrigerant temperature is detected. The third temperature sensor 35c is installed between the heat exchanger related to heat medium 15b and the second refrigerant flow switching device 18c (and the second refrigerant flow switching device 18d), and is used as the heat exchanger related to heat medium 15b. Or the temperature of the refrigerant flowing out of the heat exchanger related to heat medium 15b is detected. The third temperature sensor 35d is installed between the heat exchanger related to heat medium 15b and the expansion device 16b and flows into the heat exchanger related to heat medium 15b or flows out of the heat exchanger related to heat medium 15b. The refrigerant temperature is detected. These third temperature sensors 35 may be composed of, for example, a thermistor.

Similar to the installation position of the third temperature sensor 35d, the pressure sensor 36 is provided between the heat exchanger related to heat medium 15b and the expansion device 16b, and between the heat exchanger related to heat medium 15b and the expansion device 16b. The pressure of the flowing refrigerant is detected.

The control device described above controls the heat medium flow path of the first heat medium flow switching device 22 and the second heat medium flow switching device 23, thereby using the heat medium from the heat exchangers between heat mediums 15a on the use side. It is possible to selectively control whether the heat medium flows into the heat exchanger 26 or the heat medium from the heat exchanger related to heat medium 15 b flows into the use side heat exchanger 26. In other words, the control device controls the heat medium flow paths of the first heat medium flow switching device 22 and the second heat medium flow switching device 23, thereby allowing the inflow side flow path and the outflow side of the use side heat exchanger 26. The flow path can be selectively communicated between the heat exchanger related to heat medium 15a and the heat exchanger related to heat medium 15b.

As described above, in the air conditioner 101, the outdoor unit 1 and the heat medium relay unit 3 are connected via the heat exchanger related to heat medium 15a and the heat exchanger related to heat medium 15b provided in the heat medium converter 3. The heat medium converter 3 and the indoor unit 2 are also connected via the heat exchanger related to heat medium 15a and the heat exchanger related to heat medium 15b. That is, in the air conditioner 101, the refrigerant circulating in the refrigerant circuit A and the heat medium circulating in the heat medium circuit B are heated via the intermediate heat exchanger 15a and the intermediate heat exchanger 15b. It is to be exchanged. Therefore, if a heat medium such as water or antifreeze is circulated in the indoor unit 2, the refrigerant will not circulate, so that the refrigerant does not leak into the indoor space 7 and the like, and the air has improved safety. The harmony device 101 can be obtained.

Next, each operation mode performed by the air conditioning apparatus 101 will be described.
The air conditioner 101 can execute the cooling operation mode or the heating operation mode in the indoor unit 2 based on an instruction from each indoor unit 2. That is, the air conditioning apparatus 101 can perform the same operation for all the indoor units 2 and can also perform different operations for each indoor unit 2.

As an operation mode performed by the air conditioner 100, a cooling only operation mode in which all of the driven indoor units 2 perform a cooling operation, and a heating only operation mode in which all of the driven indoor units 2 perform a heating operation. There are a cooling main operation mode in which the cooling load is larger and a heating main operation mode in which the heating load is larger. Hereinafter, each operation mode will be described together with the refrigerant on the heat source side and the flow of the heat medium.

(Cooling mode only)
FIG. 10 is a refrigerant circuit diagram illustrating a refrigerant flow when the air-conditioning apparatus 101 according to Embodiment 2 of the present invention is in the cooling only operation mode. In FIG. 10, the cooling only operation mode will be described by taking as an example a case where a cooling load is generated only in the use side heat exchanger 26a and the use side heat exchanger 26b. In FIG. 10, pipes indicated by bold lines indicate pipes through which the refrigerant and the heat medium flow, and the direction in which the refrigerant flows is indicated by a solid line arrow, and the direction in which the heat medium flows is indicated by a broken line arrow.

In the cooling only operation mode shown in FIG. 10, in the outdoor unit 1, the control device sends the gas refrigerant discharged from the compressor 10 to the heat source side heat exchanger 12 with respect to the first refrigerant flow switching device 11. The refrigerant flow path is switched so as to flow in. Further, the control device includes the opening / closing device 17 in the open state, the second refrigerant flow switching device 18a and the second refrigerant flow switching device 18c in the open state, and the second refrigerant flow switching device 18b and the second refrigerant flow passage. Open / close control is performed so that the switching device 18d is closed. Then, in the heat medium converter 3, the control device drives the pump 21a and the pump 21b, opens the heat medium flow control device 25a and the heat medium flow control device 25b, and heat medium flow control device 25c and the heat medium flow control. The apparatus 25d is fully closed so that the heat medium circulates between each of the heat exchanger related to heat medium 15a and the heat exchanger related to heat medium 15b and the use side heat exchanger 26a and the use side heat exchanger 26b. ing.

First, the flow of the refrigerant in the refrigerant circuit A will be described with reference to FIG. The low-temperature and low-pressure gas refrigerant is compressed by the compressor 10 and discharged as a high-temperature and high-pressure gas refrigerant. Here, since the refrigerant is carbon dioxide, it becomes a gas refrigerant in a supercritical state. The high-temperature and high-pressure gas refrigerant discharged from the compressor 10 flows into the heat source side heat exchanger 12 via the first refrigerant flow switching device 11. The gas refrigerant flowing into the heat source side heat exchanger 12 radiates heat to the outdoor air. At this time, since the refrigerant is carbon dioxide, the high-temperature and high-pressure gas refrigerant that has flowed into the heat source-side heat exchanger 12 flows out of the heat source-side heat exchanger 12 in a supercritical state in a temperature-decreasing state. The supercritical high-pressure refrigerant that has flowed out of the heat source side heat exchanger 12 flows out of the outdoor unit 1 and flows into the heat medium relay unit 3 through the refrigerant pipe 4.

The high-pressure refrigerant that has flowed into the heat medium relay unit 3 is branched after passing through the opening / closing device 17, and flows into the expansion device 16a and the expansion device 16b, respectively. The high-pressure refrigerant flowing into the expansion device 16a and the expansion device 16b is expanded and depressurized to become a low-temperature and low-pressure gas-liquid two-phase refrigerant. This low-temperature low-pressure gas-liquid two-phase refrigerant flows into each of the heat exchanger related to heat medium 15a and the heat exchanger related to heat medium 15b acting as an evaporator, and absorbs heat from the heat medium circulating in the heat medium circuit B. As a result, the heat medium evaporates while cooling, and becomes a low-temperature and low-pressure gas refrigerant. The gas refrigerant that has flowed out of the heat exchanger related to heat medium 15a and the heat exchanger related to heat medium 15b passes through the second refrigerant flow switching device 18a and the second refrigerant flow switching device 18c, respectively, to the heat medium converter 3. And flows into the outdoor unit 1 again through the refrigerant pipe 4.

The gas refrigerant that has flowed into the outdoor unit 1 is again sucked into the compressor 10 via the first refrigerant flow switching device 11 and the accumulator 19.

At this time, the control device makes the superheat (superheat degree) obtained as a difference between the temperature detected by the third temperature sensor 35a and the temperature detected by the third temperature sensor 35b constant for the expansion device 16a. The opening is controlled so that Similarly, the control device opens the expansion device 16b so that the superheat obtained as a difference between the temperature detected by the third temperature sensor 35c and the temperature detected by the third temperature sensor 35d is constant. Control the degree.

Next, the flow of the heat medium in the heat medium circuit B will be described with reference to FIG.
In the cooling only operation mode, the cooling heat of the refrigerant is transmitted to the heat medium in both the heat exchanger 15a and the heat exchanger 15b, and the cooled heat medium is circulated by the pump 21a and the pump 21b. It circulates in the circuit B.

A part of the heat medium pressurized and discharged by the pump 21a and the pump 21b flows out of the heat medium converter 3 via the second heat medium flow switching device 23a, and passes through the heat medium pipe 5, It flows into the indoor unit 2a. The remaining part of the heat medium pressurized and discharged by the pump 21a and the pump 21b flows out of the heat medium converter 3 via the second heat medium flow switching device 23b and passes through the heat medium pipe 5. Flows into the indoor unit 2b. Here, since the heat medium flow control device 25c and the heat medium flow control device 25d are in a fully closed state, the heat medium passes through the second heat medium flow switching device 23c and the second heat medium flow switching device 23d. Therefore, the air does not flow into the indoor unit 2c and the indoor unit 2d, respectively.

The heat medium flowing into the indoor unit 2a and the indoor unit 2b flows into the use side heat exchanger 26a and the use side heat exchanger 26b, respectively. The indoor space 7 is cooled by the heat medium flowing into the use side heat exchanger 26a and the use side heat exchanger 26b absorbing heat from the room air. The heat medium flowing out from the use side heat exchanger 26a and the use side heat exchanger 26b flows out from the indoor unit 2a and the indoor unit 2b, respectively, and flows into the heat medium converter 3 via the heat medium pipe 5. To do.

The heat medium flowing into the heat medium converter 3 flows into the heat medium flow control device 25a and the heat medium flow control device 25b. At this time, the heat medium flow rate adjusting device 25a and the heat medium flow rate adjusting device 25b control the flow rate of the heat medium to a flow rate necessary to cover the air conditioning load required in the room, so that the use side heat exchanger 26a and It flows into the use side heat exchanger 26b. The heat medium that has flowed out of the heat medium flow control device 25a flows into the heat exchanger related to heat medium 15a and the heat exchanger related to heat medium 15b, respectively, via the first heat medium flow switching device 22a. Similarly, the heat medium flowing out from the heat medium flow control device 25b flows into the heat exchanger related to heat medium 15a and the heat exchanger related to heat medium 15b via the first heat medium flow switching device 22b. To do. The heat medium flowing into the heat exchanger related to heat medium 15a and the heat exchanger related to heat medium 15b is again sucked into the pump 21a and the pump 21b, respectively. At this time, the first heat medium flow switching device 22 and the second heat medium flow switching device 23 ensure a flow path that flows to both the heat exchanger related to heat medium 15a and the heat exchanger related to heat medium 15b. In addition, the intermediate opening is set.

The air conditioning load required in the indoor space 7 is the difference between the temperature detected by the first temperature sensor 31 a or the temperature detected by the first temperature sensor 31 b and the temperature detected by the second temperature sensor 34. Can be covered by maintaining the target value. Originally, the cooling operation by the use side heat exchanger 26 should be controlled by the temperature difference between the inlet and the outlet, but the temperature of the heat medium on the inlet side of the use side heat exchanger 26 is the first temperature sensor 31. By using the first temperature sensor 31, the number of temperature sensors can be reduced, and the system can be configured at low cost. As the outlet temperature of the heat exchanger related to heat medium 15, either the temperature of the first temperature sensor 31a or the first temperature sensor 31b may be used, or the average temperature thereof may be used.

When the above cooling only operation mode is carried out, it is not necessary to flow the heat medium to the use side heat exchanger 26 (including the thermo-off) without the heat load. The heat medium is prevented from flowing to the use side heat exchanger 26. In FIG. 10, a heat medium is flowing because there is a heat load in the use side heat exchanger 26a and the use side heat exchanger 26b, but in the use side heat exchanger 26c and the use side heat exchanger 26d, the heat load is passed. The corresponding heat medium flow control device 25c and heat medium flow control device 25d are fully closed. When a heat load is generated from the use side heat exchanger 26c or the use side heat exchanger 26d, the heat medium flow control device 25c or the heat medium flow control device 25d is opened, and the heat medium can be circulated. That's fine.

(All heating operation mode)
FIG. 11 is a refrigerant circuit diagram illustrating a refrigerant flow when the air-conditioning apparatus 101 according to Embodiment 2 of the present invention is in the heating only operation mode. In FIG. 11, the heating only operation mode will be described by taking as an example a case where a thermal load is generated only in the use side heat exchanger 26a and the use side heat exchanger 26b. In FIG. 11, the pipes indicated by bold lines indicate the pipes through which the refrigerant and the heat medium flow. The flow direction of the refrigerant is indicated by solid arrows, and the direction in which the heat medium flows is indicated by broken line arrows.

In the heating only operation mode shown in FIG. 11, in the outdoor unit 1, the control device converts the gas refrigerant discharged from the compressor 10 into the heat source side heat exchanger 12 with respect to the first refrigerant flow switching device 11. The refrigerant flow path is switched so as to flow into the heat medium relay unit 3 without going through. Further, the control device includes the opening / closing device 17 in the open state, the second refrigerant flow switching device 18a and the second refrigerant flow switching device 18c in the open state, and the second refrigerant flow switching device 18b and the second refrigerant flow passage. Open / close control is performed so that the switching device 18d is closed. Then, in the heat medium converter 3, the control device drives the pump 21a and the pump 21b, opens the heat medium flow control device 25a and the heat medium flow control device 25b, and heat medium flow control device 25c and the heat medium flow control. The apparatus 25d is fully closed so that the heat medium circulates between each of the heat exchanger related to heat medium 15a and the heat exchanger related to heat medium 15b and the use side heat exchanger 26a and the use side heat exchanger 26b. ing.

First, the flow of the refrigerant in the refrigerant circuit A will be described with reference to FIG. The low-temperature and low-pressure gas refrigerant is compressed by the compressor 10 and discharged as a high-temperature and high-pressure gas refrigerant. Here, since the refrigerant is carbon dioxide, it becomes a gas refrigerant in a supercritical state. The high-temperature and high-pressure gas refrigerant discharged from the compressor 10 flows out of the outdoor unit 1 via the first refrigerant flow switching device 11. The high-temperature and high-pressure gas refrigerant that has flowed out of the outdoor unit 1 flows into the heat medium relay unit 3 via the refrigerant pipe 4.

The high-temperature and high-pressure gas refrigerant flowing into the heat medium relay unit 3 is branched and acts as a radiator (gas cooler) via the second refrigerant flow switching device 18a and the second refrigerant flow switching device 18c. It flows into each of the heat exchanger related to heat medium 15a and the heat exchanger related to heat medium 15b. The high-temperature and high-pressure gas refrigerant flowing into the heat exchanger related to heat medium 15a and the heat exchanger related to heat medium 15b dissipates heat while heating the heat medium by dissipating heat to the heat medium circulating in the heat medium circuit B, In the supercritical state, the temperature decreases and flows out of the heat exchanger related to heat medium 15a and the heat exchanger related to heat medium 15b. The high-pressure refrigerant flowing out of the heat exchanger related to heat medium 15a and the heat exchanger related to heat medium 15b is expanded and depressurized by the expansion device 16a and the expansion device 16b, respectively, and becomes a low-temperature and low-pressure gas-liquid two-phase refrigerant. This low-temperature and low-pressure gas-liquid two-phase refrigerant flows out of the heat medium relay unit 3 through the opening / closing device 17, and flows into the outdoor unit 1 again through the refrigerant pipe 4.

The gas-liquid two-phase refrigerant that has flowed into the outdoor unit 1 flows into the heat source side heat exchanger 12. The gas-liquid two-phase refrigerant flowing into the heat source side heat exchanger 12 is vaporized while absorbing heat from the outdoor air, and becomes a low-temperature and low-pressure gas refrigerant. The gas refrigerant flowing out from the heat source side heat exchanger 12 is again sucked into the compressor 10 via the first refrigerant flow switching device 11 and the accumulator 19.

At this time, the control device makes a subcool (supercooling) obtained as a difference between a value obtained by converting the pressure detected by the pressure sensor 36 into a saturation temperature and a temperature detected by the third temperature sensor 35b. The degree of opening is controlled so that the degree is constant. Similarly, the control device makes the subcool obtained as a difference between the value obtained by converting the pressure detected by the pressure sensor 36 into the saturation temperature and the temperature detected by the third temperature sensor 35d constant for the expansion device 16b. The opening is controlled so that

If the temperature at the intermediate position of the heat exchanger related to heat medium 15 can be measured, the temperature at the intermediate position may be used instead of the pressure sensor 36. In this case, the system can be configured at low cost.

Next, the flow of the heat medium in the heat medium circuit B will be described with reference to FIG.
In the heating only operation mode, the heat of the refrigerant is transmitted to the heat medium in both the heat exchanger 15a and the heat exchanger 15b, and the heated heat medium is circulated by the pump 21a and the pump 21b. It circulates in the circuit B.

The heat medium flowing into the indoor unit 2a and the indoor unit 2b flows into the use side heat exchanger 26a and the use side heat exchanger 26b, respectively. Heating of the indoor space 7 is performed by the heat medium flowing into the use side heat exchanger 26a and the use side heat exchanger 26b radiating heat to the indoor air. The heat medium flowing out from the use side heat exchanger 26a and the use side heat exchanger 26b flows out from the indoor unit 2a and the indoor unit 2b, respectively, and flows into the heat medium converter 3 via the heat medium pipe 5. To do.

The air conditioning load required in the indoor space 7 is the difference between the temperature detected by the first temperature sensor 31 a or the temperature detected by the first temperature sensor 31 b and the temperature detected by the second temperature sensor 34. Can be covered by maintaining the target value. Originally, the heating operation by the use side heat exchanger 26 should be controlled by the temperature difference between the inlet and the outlet, but the temperature of the heat medium on the inlet side of the use side heat exchanger 26 is the first temperature sensor 31. By using the first temperature sensor 31, the number of temperature sensors can be reduced, and the system can be configured at low cost. As the outlet temperature of the heat exchanger related to heat medium 15, either the temperature of the first temperature sensor 31a or the first temperature sensor 31b may be used, or the average temperature thereof may be used.

When the above heating only operation mode is carried out, it is not necessary to flow the heat medium to the use side heat exchanger 26 (including the thermo-off) without a heat load. The heat medium is prevented from flowing to the use side heat exchanger 26. In FIG. 11, a heat medium is flowing because there is a heat load in the use side heat exchanger 26a and the use side heat exchanger 26b, but in the use side heat exchanger 26c and the use side heat exchanger 26d, the heat load is passed. The corresponding heat medium flow control device 25c and heat medium flow control device 25d are fully closed. When a heat load is generated from the use side heat exchanger 26c or the use side heat exchanger 26d, the heat medium flow control device 25c or the heat medium flow control device 25d is opened, and the heat medium can be circulated. That's fine.

(Cooling operation mode)
FIG. 12 is a refrigerant circuit diagram illustrating a refrigerant flow when the air-conditioning apparatus 101 according to Embodiment 2 of the present invention is in the cooling main operation mode. In FIG. 12, the cooling main operation mode will be described by taking as an example a case where a cooling load is generated in the use side heat exchanger 26a and a heating load is generated in the use side heat exchanger 26b. In FIG. 12, the pipes represented by bold lines indicate the pipes through which the refrigerant and the heat medium flow, and the direction in which the refrigerant flows is indicated by solid arrows, and the direction in which the heat medium flows is indicated by broken arrows.

In the cooling main operation mode shown in FIG. 12, in the outdoor unit 1, the control device sends the gas refrigerant discharged from the compressor 10 to the heat source side heat exchanger 12 with respect to the first refrigerant flow switching device 11. The refrigerant flow path is switched so as to flow in. Further, the control device includes the expansion device 16a in a fully open state, the opening / closing device 17 in a closed state, the second refrigerant flow switching device 18a and the second refrigerant flow switching device 18d in an open state, and the second refrigerant flow switching device. Opening / closing control is performed so that 18b and the second refrigerant flow switching device 18c are closed. Then, in the heat medium converter 3, the control device drives the pump 21a and the pump 21b, opens the heat medium flow control device 25a and the heat medium flow control device 25b, and heat medium flow control device 25c and the heat medium flow control. The apparatus 25d is fully closed, the heat medium between the heat exchanger 15a and the use side heat exchanger 26a, and the heat medium between the heat exchanger 15b and the use side heat exchanger 26b, respectively. Is trying to circulate.

The high-pressure refrigerant that has flowed into the heat medium relay unit 3 flows into the heat exchanger related to heat medium 15b that acts as a radiator (gas cooler) via the refrigerant pipe 4 and the second refrigerant flow switching device 18d. The high-pressure refrigerant that has flowed into the heat exchanger related to heat medium 15b dissipates heat to the heat medium circulating in the heat medium circuit B so that the heat medium is further dissipated while heating the heat medium, and the temperature is lowered. It flows out of the intermediate heat exchanger 15b. The high-pressure refrigerant that has flowed out of the heat exchanger related to heat medium 15b is expanded and depressurized by the expansion device 16b, and becomes a low-temperature and low-pressure gas-liquid two-phase refrigerant. The low-temperature and low-pressure gas-liquid two-phase refrigerant flows into the heat exchanger related to heat medium 15a acting as an evaporator via the expansion device 16a. The low-temperature and low-pressure gas-liquid two-phase refrigerant that has flowed into the heat exchanger related to heat medium 15a evaporates while cooling the heat medium by absorbing heat from the heat medium circulating in the heat medium circuit B, so It becomes. The gas refrigerant that has flowed out of the heat exchanger related to heat medium 15a flows out of the heat medium converter 3 through the second refrigerant flow switching device 18a, and flows into the outdoor unit 1 again through the refrigerant pipe 4. To do.

At this time, the control device opens the expansion device 16b so that the superheat obtained as a difference between the temperature detected by the third temperature sensor 35a and the temperature detected by the third temperature sensor 35b is constant. Control the degree.
The control device has a constant subcool with respect to the expansion device 16b, which is obtained as a difference between a value obtained by converting the pressure detected by the pressure sensor 36 into a saturation temperature and a temperature detected by the third temperature sensor 35d. Thus, the opening degree may be controlled. Alternatively, the expansion device 16b may be fully opened, and the superheat or subcool may be controlled by the expansion device 16a.

Next, the flow of the heat medium in the heat medium circuit B will be described with reference to FIG.
In the cooling main operation mode, the heat of the refrigerant is transmitted to the heat medium in the heat exchanger related to heat medium 15b, and the heated heat medium is circulated in the heat medium circuit B by the pump 21b. Further, in the cooling main operation mode, the cold heat of the refrigerant is transmitted to the heat medium in the heat exchanger related to heat medium 15a, and the cooled heat medium flows through the heat medium circuit B by the pump 21a.

The heat medium pressurized and discharged by the pump 21b flows out of the heat medium converter 3 through the second heat medium flow switching device 23b, and flows into the indoor unit 2b through the heat medium pipe 5. . The heat medium pressurized and discharged by the pump 21a flows out of the heat medium converter 3 through the second heat medium flow switching device 23a, and flows into the indoor unit 2a through the heat medium pipe 5. . Here, since the heat medium flow control device 25c and the heat medium flow control device 25d are in a fully closed state, the heat medium passes through the second heat medium flow switching device 23c and the second heat medium flow switching device 23d. Therefore, the air does not flow into the indoor unit 2c and the indoor unit 2d, respectively.

The heat medium flowing into the indoor unit 2b flows into the use side heat exchanger 26b, and the heat medium flowing into the indoor unit 2a flows into the use side heat exchanger 26a. The heat medium that has flowed into the use-side heat exchanger 26b radiates heat to the indoor air, thereby heating the indoor space 7. On the other hand, the heat medium that has flowed into the use-side heat exchanger 26a absorbs heat from the indoor air, whereby the indoor space 7 is cooled. Then, the heat medium that has flowed out of the use side heat exchanger 26 b and whose temperature has decreased to some extent flows out of the indoor unit 2 b and flows into the heat medium converter 3 via the heat medium pipe 5. On the other hand, the heat medium that has flowed out of the use-side heat exchanger 26 a and whose temperature has increased to some extent flows out of the indoor unit 2 a and flows into the heat medium converter 3 through the heat medium pipe 5.

The heat medium flowing into the heat medium converter 3 from the use side heat exchanger 26b flows into the heat medium flow control device 25b, and the heat medium flowing into the heat medium converter 3 from the use side heat exchanger 26a is the heat medium. It flows into the flow rate adjusting device 25a. At this time, the heat medium flow rate adjusting device 25a and the heat medium flow rate adjusting device 25b control the flow rate of the heat medium to a flow rate necessary to cover the air conditioning load required in the room. It flows into the use side heat exchanger 26b. The heat medium flowing out from the heat medium flow control device 25b flows into the heat exchanger related to heat medium 15b via the first heat medium flow switching device 22b and is sucked into the pump 21b again. On the other hand, the heat medium flowing out from the heat medium flow control device 25a flows into the heat exchanger related to heat medium 15a via the first heat medium flow switching device 22a and is sucked into the pump 21a again. As described above, in the cooling main operation mode, the warm heat medium and the cold heat medium are not mixed by the action of the first heat medium flow switching device 22 and the second heat medium flow switching device 23, respectively. A heat load and a cold load are fed into the use side heat exchanger 26.

The air conditioning load required in the indoor space 7 is the difference between the temperature detected by the first temperature sensor 31b on the heating side and the temperature detected by the second temperature sensor 34b on the heating side, and the second on the cooling side. It can be covered by maintaining the difference between the temperature detected by the temperature sensor 34b and the temperature detected by the first temperature sensor 31a at the target value.

When the above cooling main operation mode is carried out, it is not necessary to flow the heat medium to the use side heat exchanger 26 (including the thermo-off) having no heat load. The heat medium is prevented from flowing to the use side heat exchanger 26. In FIG. 5, a heat medium flows because there is a heat load in the use side heat exchanger 26a and the use side heat exchanger 26b. However, in the use side heat exchanger 26c and the use side heat exchanger 26d, the heat load is supplied. The corresponding heat medium flow control device 25c and heat medium flow control device 25d are fully closed. When a heat load is generated from the use side heat exchanger 26c or the use side heat exchanger 26d, the heat medium flow control device 25c or the heat medium flow control device 25d is opened, and the heat medium can be circulated. That's fine.

(Heating main operation mode)
FIG. 13 is a refrigerant circuit diagram illustrating a refrigerant flow when the air-conditioning apparatus 101 according to Embodiment 2 of the present invention is in the heating main operation mode. In FIG. 13, the heating main operation mode will be described by taking as an example a case where a thermal load is generated in the use side heat exchanger 26a and a cold load is generated in the use side heat exchanger 26b. In FIG. 13, the pipes indicated by bold lines indicate the pipes through which the refrigerant and the heat medium flow, and the direction in which the refrigerant flows is indicated by a solid line arrow, and the direction in which the heat medium flows is indicated by a broken line arrow.

In the heating main operation mode shown in FIG. 13, in the outdoor unit 1, the control device converts the gas refrigerant discharged from the compressor 10 into the heat source side heat exchanger 12 with respect to the first refrigerant flow switching device 11. The refrigerant flow path is switched so as to flow into the heat medium relay unit 3 without going through. The control device includes a throttle device 16a in a fully open state, an opening / closing device 17 in a closed state, a second refrigerant flow switching device 18a and a second refrigerant flow switching device 18d in a closed state, and a second refrigerant flow switching device. Opening / closing control is performed so that 18b and the second refrigerant flow switching device 18c are opened. Then, in the heat medium converter 3, the control device drives the pump 21a and the pump 21b, opens the heat medium flow control device 25a and the heat medium flow control device 25b, and heat medium flow control device 25c and the heat medium flow control. The apparatus 25d is fully closed, the heat medium between the heat exchanger 15a and the use side heat exchanger 26a, and the heat medium between the heat exchanger 15b and the use side heat exchanger 26b, respectively. Is trying to circulate.

The high-temperature and high-pressure gas refrigerant that has flowed into the heat medium relay unit 3 flows into the heat exchanger related to heat medium 15b acting as a radiator (gas cooler) via the second refrigerant flow switching device 18c. The high-temperature and high-pressure gas refrigerant flowing into the intermediate heat exchanger 15b radiates heat to the heat medium circulating in the heat medium circuit B. At this time, since the refrigerant is carbon dioxide, the high-temperature and high-pressure gas refrigerant that has flowed into the heat exchanger related to heat medium 15b flows out of the heat exchanger related to heat medium 15b in a supercritical state in a temperature-decreasing state. To do. The supercritical high-pressure refrigerant flowing out of the heat exchanger related to heat medium 15b is expanded and depressurized by the expansion device 16b, and becomes a low-temperature low-pressure gas-liquid two-phase refrigerant. The low-temperature and low-pressure gas-liquid two-phase refrigerant flows into the heat exchanger related to heat medium 15a acting as an evaporator via the expansion device 16a. The low-temperature and low-pressure gas-liquid two-phase refrigerant that has flowed into the heat exchanger related to heat medium 15a cools the heat medium by absorbing heat from the heat medium circulating in the heat medium circuit B. The gas-liquid two-phase refrigerant that has flowed out of the heat exchanger related to heat medium 15 a flows out of the heat medium converter 3 via the second refrigerant flow switching device 18 b and the branch pipe 4 d, and then passes through the refrigerant pipe 4. Then, it flows into the outdoor unit 1 again.

The gas-liquid two-phase refrigerant that has flowed into the outdoor unit 1 flows into the heat source side heat exchanger 12. The gas-liquid two-phase refrigerant flowing into the heat source side heat exchanger 12 evaporates by further absorbing heat from the outdoor air, and becomes a low-temperature and low-pressure gas refrigerant. The low-temperature and low-pressure gas refrigerant flowing out from the heat source side heat exchanger 12 is again sucked into the compressor 10 via the first refrigerant flow switching device 11 and the accumulator 19.

At this time, the control device makes the subcool obtained as a difference between the value obtained by converting the pressure detected by the pressure sensor 36 into the saturation temperature and the temperature detected by the third temperature sensor 35b constant with respect to the expansion device 16b. The opening is controlled so that
The control device may be configured such that the expansion device 16b is fully opened and the subcooling is controlled by the expansion device 16a.

Next, the flow of the heat medium in the heat medium circuit B will be described with reference to FIG.
In the heating main operation mode, the heat of the refrigerant is transmitted to the heat medium in the heat exchanger related to heat medium 15b, and the heated heat medium flows through the heat medium circuit B by the pump 21b. Further, in the heating main operation mode, the cold heat of the refrigerant is transmitted to the heat medium in the heat exchanger related to heat medium 15a, and the cooled heat medium flows through the heat medium circuit B by the pump 21a.

The heat medium pressurized and discharged by the pump 21b flows out of the heat medium converter 3 through the second heat medium flow switching device 23a, and flows into the indoor unit 2a through the heat medium pipe 5. . The heat medium pressurized and discharged by the pump 21a flows out of the heat medium converter 3 through the second heat medium flow switching device 23b, and flows into the indoor unit 2b through the heat medium pipe 5. . Here, since the heat medium flow control device 25c and the heat medium flow control device 25d are in a fully closed state, the heat medium passes through the second heat medium flow switching device 23c and the second heat medium flow switching device 23d. Therefore, the air does not flow into the indoor unit 2c and the indoor unit 2d, respectively.

The heat medium flowing into the indoor unit 2a flows into the use side heat exchanger 26a, and the heat medium flowing into the indoor unit 2b flows into the use side heat exchanger 26b. The heat medium flowing into the use side heat exchanger 26a dissipates heat to the indoor air, thereby heating the indoor space 7. On the other hand, the heat medium that has flowed into the use side heat exchanger 26b absorbs heat from the indoor air, whereby the indoor space 7 is cooled. Then, the heat medium that has flowed out of the use-side heat exchanger 26 a and whose temperature has decreased to some extent flows out of the indoor unit 2 a and flows into the heat medium converter 3 through the heat medium pipe 5. On the other hand, the heat medium that has flowed out from the use side heat exchanger 26 b and whose temperature has risen to some extent flows out from the indoor unit 2 b, and flows into the heat medium converter 3 through the heat medium pipe 5.

The heat medium flowing into the heat medium converter 3 from the use side heat exchanger 26a flows into the heat medium flow control device 25a, and the heat medium flowing into the heat medium converter 3 from the use side heat exchanger 26b is the heat medium. It flows into the flow rate adjusting device 25b. At this time, the heat medium flow control device 25a and the heat medium flow control device 25b control the flow rate of the heat medium to a flow rate necessary to cover the air conditioning load required in the room, so that the use-side heat exchanger 26a. And it flows into the use side heat exchanger 26b. The heat medium that has flowed out of the heat medium flow control device 25a flows into the heat exchanger related to heat medium 15b via the first heat medium flow switching device 22a, and is sucked into the pump 21b again. On the other hand, the heat medium flowing out from the heat medium flow control device 25b flows into the heat exchanger related to heat medium 15a via the first heat medium flow switching device 22b and is sucked into the pump 21a again. As described above, in the heating main operation mode, the warm heat medium and the cold heat medium are not mixed by the action of the first heat medium flow switching device 22 and the second heat medium flow switching device 23, It flows into the use-side heat exchanger 26 having a hot load and a cold load, respectively.

The air conditioning load required in the indoor space 7 is the difference between the temperature detected by the first temperature sensor 31b on the heating side and the temperature detected by the second temperature sensor 34a on the heating side, and the second on the cooling side. It is possible to cover the difference between the temperature detected by the temperature sensor 34b and the temperature detected by the first temperature sensor 31a so as to maintain the target value.

When carrying out the above heating main operation mode, it is not necessary to flow the heat medium to the use side heat exchanger 26 (including the thermo-off) having no heat load, so the heat medium flow control device 25 closes the flow path. The heat medium is prevented from flowing to the use side heat exchanger 26. In FIG. 6, since there is a heat load in the use-side heat exchanger 26a and the use-side heat exchanger 26b, a heat medium is flowing, but in the use-side heat exchanger 26c and the use-side heat exchanger 26d, the heat load is passed. The corresponding heat medium flow control device 25c and heat medium flow control device 25d are fully closed. When a heat load is generated from the use side heat exchanger 26c or the use side heat exchanger 26d, the heat medium flow control device 25c or the heat medium flow control device 25d is opened, and the heat medium can be circulated. That's fine.

(Refrigerant charging operation to the air conditioner 101)
The structure of the switchgear 40 installed in the air conditioner 101 according to the present embodiment is the same structure as the switchgear 207 shown in FIG. 5 installed in the air conditioner 100 according to the first embodiment. In the present embodiment, the service person connects the switch tube 209 connected to the switchgear 207 and the refrigerant cylinder 208 in the first embodiment to the switchgear 40, which will be described in the first embodiment. The refrigerant circulation circuit A may be filled with the refrigerant by the same procedure.

(Effect of Embodiment 2)
Like the above-described configuration, the air conditioner 101 is provided with the opening / closing device 40 that can form a purge state in the same manner as the opening / closing device 207 in the first embodiment, so that the refrigerant suddenly leaks or the connection pipe is disconnected. Therefore, it is possible to provide an air conditioner 101 that can significantly reduce the risk of being released in large quantities and that can safely purge the air in the connecting pipe. This is particularly effective for carbon dioxide with a high pressure.

Further, in the air conditioner 101 according to the present embodiment, a heat medium such as water or antifreeze liquid is circulated in the indoor unit 2 and the refrigerant does not circulate, so that the refrigerant leaks into the indoor space 7 and the like. Safety can be improved.

The first heat medium flow switching device 22 and the second heat medium flow switching device 23 in the present embodiment can switch a three-way flow such as a three-way valve, or a two-way flow such as an on-off valve. What is necessary is just to switch a flow path, such as combining two things which implement opening and closing of.

The first heat medium flow switching device 22 and the second heat medium flow switching device 23 in the present embodiment can change the flow rate of a three-way flow path such as a stepping motor driven mixing valve, or It is good also as what is comprised by what combined the thing which can change the flow volume of two-way flow paths, such as an electronic expansion valve. In this case, it is possible to prevent water hammer due to sudden opening and closing of the flow path.

In the present embodiment, the case where the heat medium flow control device 25 is a two-way valve has been described as an example. However, the heat medium flow control device 25 is not limited to this and is a control valve having a three-way flow path. You may make it install with the bypass pipe which bypasses 26.

The heat medium flow control device 25 may be a stepping motor driven type that can control the flow rate flowing through the flow path, or may be one in which one end of a two-way valve or a three-way valve is closed.

Further, as the heat medium flow control device 25, an apparatus that opens and closes a two-way flow path such as an open / close valve may be used, and the average flow rate may be controlled by repeating ON / OFF.

Further, as shown in FIG. 9, the second refrigerant flow switching device 18 is shown as if it were a two-way flow switching valve, but is not limited to this, and a three-way flow switching valve. A plurality of can be used so that the refrigerant flows in the same manner. Further, for the second refrigerant flow switching device 18, the second refrigerant flow switching device 18a and the second refrigerant flow switching device 18b, and the second refrigerant flow switching device 18c and the second refrigerant flow switching device 18d are provided. Each may be replaced with a four-way valve.

Moreover, although the air conditioning apparatus 101 according to the present embodiment has been described as being capable of mixed operation of cooling and heating, the present invention is not limited to this. For example, there is one heat exchanger 15 between the heat medium and one expansion device 16, and a plurality of use side heat exchangers 26 and heat medium flow control devices 25 are connected in parallel to each other in the cooling operation mode or the heating operation mode. Even if it is the structure which can implement only either, there exists the same effect.

Moreover, although the heat medium flow control apparatus 25 demonstrated to the example the case where it was incorporated in the heat medium converter 3, it is not limited to this, It is good also as what is incorporated in the indoor unit 2 side, Alternatively, the heat medium converter 3 and the indoor unit 2 may be installed separately.

In general, the heat source side heat exchanger 12 and the use side heat exchanger 26 are equipped with a blower, which often promotes condensation (heat dissipation) or evaporation (heat absorption) by blowing air. It is not limited. For example, the use-side heat exchanger 26 may be a panel heater using radiation or the like, and the heat-source-side heat exchanger 12 is a water-cooled type that moves heat by water or antifreeze. May be used. That is, the heat source side heat exchanger 12 and the use side heat exchanger 26 can be used regardless of the type as long as they have a structure capable of radiating or absorbing heat.

In the present embodiment, the case where there are four use-side heat exchangers 26 (that is, indoor units 2) has been described as an example, but the number is not particularly limited.

Moreover, although the case where there are two

heat exchangers

15a and 15b as the heat exchanger 15 between the heat medium has been described as an example, it is not limited to this, As long as it can be cooled or heated, any number may be installed.

Also, the number of

pumps

21a and 21b is not limited to one, and a plurality of small-capacity pumps may be connected in parallel.

In the present embodiment, the first heat medium flow switching device 22, the second heat medium flow switching device 23, and the heat medium flow control device 25 are connected to each use side heat exchanger 26, one by one. However, the present invention is not limited to this, and a plurality of each of the use side heat exchangers 26 may be connected. In this case, the plurality of first heat medium flow switching devices 22, the second heat medium flow switching devices 23, and the heat medium flow control devices 25 connected to the same use side heat exchanger 26 are the same. It is sufficient to operate.

Moreover, although the refrigerant | coolant with which the refrigerating cycle circuit is filled with the switchgear 40 was made into the carbon dioxide, it is not limited to this, HFO1234yf, R32, R290, HC type | system | group refrigerant | coolant, those mixed refrigerant | coolants, and other refrigerant | coolants are filled. Needless to say, it can be a thing.

Furthermore, as described above, in the present embodiment, the air conditioning apparatus 101 has been described as an example of the refrigeration cycle apparatus. Good. In this case, the open / close device 40, which is a service valve for filling the refrigerant or drawing a vacuum, may be provided on the low-pressure gas piping side of the heat source side unit in the refrigeration cycle apparatus. .

1 outdoor unit, 2, 2a to 2d indoor unit, 3 heat medium converter, 4 refrigerant piping, 4d branch piping, 5 heat medium piping, 6 outdoor space, 7 indoor space, 8 space, 9 building, 10 compressor, 11 First refrigerant flow switching device, 12 Heat source side heat exchanger, 15, 15a, 15b Heat exchanger between heat medium, 16, 16a, 16b Throttle device, 17 Opening / closing device, 18, 18a-18d Second refrigerant flow switching Device, 19 accumulator, 21, 21a, 21b pump, 22, 22a-22d, first heat medium flow switching device, 23, 23a-23d, second heat medium flow switching device, 25, 25a-25d, heat medium flow rate adjustment Equipment, 26, 26a-26d Use side heat exchanger, 31, 31a, 31b First temperature sensor, 34, 34a-34d Second temperature sensor, 35, 35a- 5d 3rd temperature sensor, 36 pressure sensor, 40 switchgear, 100 air conditioner, 101 air conditioner, 200 outdoor unit, 201 compressor, 202 oil separator, 203 flow path switching device, 204 heat source side heat exchanger, 205 accumulator, 206 oil return capillary, 207 opening and closing device, 207a valve body, 207b sealing material, 207c flow path, 208 refrigerant cylinder, 209 connecting pipe, 210 charging hose, 211 plug, 300, 300a to 300d indoor unit, 301 , 301a to 301d, use side heat exchangers, 302, 302a to 302d, expansion devices, 400, 400a and 400b, piping, A refrigerant circulation circuit, and B heat medium circulation circuit.

Claims

A heat source side unit including a compressor and a heat source side heat exchanger;
A user-side unit with a user-side heat exchanger;
A throttle device for decompressing the refrigerant;
A valve body through which a flow path for the refrigerant passes is connected to a refrigerant cylinder or the like through a connecting pipe, and an intake port through which the refrigerant is drawn from the refrigerant cylinder or the like, and an intake from the refrigerant cylinder or the like through the intake port An opening / closing device having a supply port through which the refrigerant flows out, and a purge port for releasing the refrigerant supplied from the refrigerant cylinder together with the air in the connection pipe;
With
At least the compressor, the heat source side heat exchanger, the expansion device and the use side heat exchanger are connected by a refrigerant pipe to form a refrigeration cycle circuit in which the refrigerant circulates,
The supply port is connected to a refrigerant pipe in the refrigeration cycle circuit,
The valve body has a communication state in which the suction port and the supply port communicate with each other by switching the flow path so that the refrigerant can be sealed in the refrigeration cycle circuit from the refrigerant cylinder or the like. And the purge port communicate with each other, a purge state in which the refrigerant supplied from the refrigerant cylinder or the like together with the air in the connection pipe can be discharged from the purge port, and the suction port, the supply port, and the It is possible to switch to any of the three closed states where none of the purge ports communicate.
The refrigerant is a refrigeration cycle apparatus that operates in a supercritical state in at least a part of a circulation path of the refrigeration cycle circuit.
The refrigeration cycle apparatus according to claim 1, wherein the supply port is connected to a refrigerant pipe constituting the heat source side unit.
The refrigeration cycle apparatus according to claim 1 or 2, wherein the valve body is formed in a ball shape.
4. The refrigeration cycle apparatus according to claim 1, wherein a flow path through which the refrigerant in the purge state flows is smaller than a flow path through which the refrigerant in the communication state flows.
The refrigeration cycle apparatus according to any one of claims 1 to 4, further comprising a plug that closes the purge port of the switchgear.
The refrigeration cycle apparatus according to any one of claims 1 to 5, wherein the refrigerant to be sealed in the refrigeration cycle circuit is carbon dioxide.
The step of bringing the opening and closing device provided in the refrigeration cycle apparatus according to any one of claims 1 to 6 into the closed state;
Connecting the refrigerant cylinder or the like to the suction port of the switchgear through the connection pipe;
Setting the open / close device to the purge state, and releasing the refrigerant supplied from the refrigerant cylinder or the like together with the air in the connection pipe from the purge port of the open / close device;
Placing the opening / closing device in the communication state, supplying a refrigerant from the refrigerant cylinder, etc., circulating the refrigerant from the suction port to the supply port of the opening / closing device, and enclosing a predetermined amount of refrigerant in the refrigeration cycle circuit; ,
After enclosing a refrigerant in the refrigeration cycle circuit, and placing the switchgear in the closed state;
A refrigerant filling method having