JP7412887B2 - Air conditioner and flow path switching valve - Google Patents

Description

The present disclosure relates to an air conditioner and a flow path switching valve.

Patent Document 1 discloses an air conditioner that includes an indoor unit and an outdoor unit. A solenoid valve and an expansion valve are connected to the refrigerant pipe connected to the indoor unit. When the refrigerant leak detector detects a refrigerant leak in the indoor unit, the solenoid valve and expansion valve are closed.

Japanese Patent Application Publication No. 2012-13339

A solenoid valve or an expansion valve as disclosed in Patent Document 1 has a structure in which an internal flow path is opened and closed by a valve. Therefore, due to its structure, the internal flow path is relatively narrow. A shutoff valve as disclosed in Patent Document 1 is in a closed state when a refrigerant leaks, but is basically in an open state during normal operation other than that. For this reason, there is a problem in that the pressure loss in the refrigerant flow path during normal operation increases due to the provision of the cutoff valve.

The present disclosure is to reduce pressure loss through isolation valves.

The first aspect includes a heat source circuit (20a) to which a compressor (21) and a heat source heat exchanger (22) are connected, and a utilization circuit (30a) to which a utilization heat exchanger (31) is connected, The air conditioner is equipped with a refrigerant circuit (10a) in which a refrigeration cycle is performed, and the refrigerant circuit (10a) has refrigerant channels (41, 42) connected to both ends of the utilization circuit (30a), respectively. further comprising a cutoff valve connected to each of the two refrigerant flow paths (41, 42), and at least one of the two cutoff valves is configured to shut off the refrigerant when leakage occurs in the utilization circuit (30a). This air conditioner is characterized by being configured with flow path switching valves (V1, V2) that switch the flow paths so as to block the refrigerant flow paths (41, 42).

In the first aspect, since the cutoff valve is composed of the flow path switching valve (V1, V2), pressure loss due to the cutoff valve can be reduced compared to, for example, a solenoid valve or an expansion valve.

In a second aspect, in the first aspect, the refrigerant flow path (41, 42) is a first flow path (41, 42) formed on the heat source circuit (20a) side of the flow path switching valve (V1, V2). 41a, 42a) and a second flow path (41b, 42b) formed on the usage circuit (30a) side of the flow path switching valve (V1, V2), ) is a first port (P1) connected to the first flow path (41a, 42a), a second port (P2) connected to the second flow path (41b, 42b), and a third port (P3). ), and a four-way switching valve (51, 52) having a fourth port (P4).

In the second aspect, the flow path switching valves (V1, V2) are constituted by four-way switching valves (51, 52). When the four-way switching valve (51, 52) is placed in the first state, each refrigerant flow path (41, 42) becomes conductive. When the four-way switching valve (51, 52) is placed in the second state, each refrigerant flow path (41, 42) is blocked.

In a third aspect, in the second aspect, the refrigerant circuit (10a) is a high-pressure introduction circuit (60) that introduces the high-pressure refrigerant in the first flow path (41a, 42a) into the third port (P3). The air conditioner is characterized in that the four-way switching valve (51, 52) is a differential pressure drive type driven by the high-pressure refrigerant introduced into the third port (P3).

In the third aspect, the high-pressure refrigerant flowing through the first flow path (41a, 42a) is introduced into the third port (P3). The flow paths of the four-way switching valves (51, 52) are switched using the pressure of this high-pressure refrigerant as a driving source.

In a fourth aspect, in the third aspect, the refrigerant circuit (10a) is a first refrigeration cycle in which the heat source heat exchanger (22) is a radiator and the utilization heat exchanger (31) is an evaporator. , a second refrigeration cycle in which the utilization heat exchanger (31) is a radiator and the heat source heat exchanger (22) is an evaporator, and the high pressure introduction circuit (60) has at least two The high-pressure refrigerant in the first flow path (41a, 42a) having a higher pressure among the two first flow paths (41a, 42a) is introduced into the third port (P3). It is an air conditioner.

In the fourth aspect, high-pressure refrigerant can be introduced into the third port (P3) in both the first refrigeration cycle and the second refrigeration cycle. This high-pressure refrigerant can be used as a driving source for the four-way switching valves (51, 52).

In a fifth aspect, in the fourth aspect, the high pressure introduction circuit (60) connects the first flow path (41a, 42a) of the refrigerant flow path (41) on the liquid side and the third port (P3). and a gas side introduction path (62) that connects the first flow path (41a, 42a) of the refrigerant flow path (42) on the gas side with the third port (P3). ), the liquid side introduction path (61) is provided with a first on-off valve (64) that is opened during the first refrigeration cycle, and the gas side introduction path (62) is provided with a first on-off valve (64) that is opened during the first refrigeration cycle. This air conditioner is characterized by being provided with a second on-off valve (65) that is opened during the refrigeration cycle.

In the fifth aspect, by opening the first on-off valve (64) during the first refrigeration cycle, high-pressure liquid refrigerant can be introduced into the third port (P3). By opening the second on-off valve (65) during the second refrigeration cycle, high-pressure gas refrigerant can be introduced into the third port (P3).

In a sixth aspect, in any one of the third to fifth aspects, the four-way switching valve (51, 52) has a closed fourth port (P4), and the four-way switching valve is in a first state. (51, 52) communicates between the first port (P1) and the second port (P2) and communicates between the third port (P3) and the fourth port (P4),
The four-way switching valve (51, 52) in the second state communicates between the first port (P1) and the third port (P3) and communicates between the second port (P2) and the fourth port (P4). It is characterized by

In the sixth aspect, when the four-way switching valve (51, 52) enters the first state, the first port (P1) and the second port (P2) communicate with each other, and the refrigerant flow path (41, 42) becomes conductive. . The refrigerant on the third port (P3) side does not pass through the blocked fourth port (P4). When the four-way switching valve (51, 52) enters the second state, the utilization circuit (30a) is substantially closed to the fourth port (P4). The utilized circuit (30a) becomes a closed circuit.

In a seventh aspect, in any one of the second to sixth aspects, the four-way switching valve (51, 52) has a low pressure pipe (55, 56) communicating with the utilization circuit (30a), The air conditioner is characterized in that the air conditioner is switched to the second state by a pressure difference between the high pressure refrigerant and the internal pressure of the low pressure pipes (55, 56).

In the seventh aspect, when refrigerant leakage occurs in the utilization circuit (30a), the internal pressure of the utilization circuit (30a) decreases, and as a result, the internal pressure of the low pressure pipes (55, 56) decreases. The four-way switching valve (51, 52) switches to the second state using the pressure difference between the high-pressure refrigerant and the internal pressure of the low-pressure pipe (55, 56) in this state. When refrigerant leaks, the four-way switching valve (51, 52) can be automatically switched to the second state.

In an eighth aspect, in the first aspect, the refrigerant passage (41, 42) is a first passage (41, 42) formed on the heat source circuit (20a) side of the passage switching valve (V1, V2). 41a, 42a) and a second flow path (41b, 42b) formed on the usage circuit (30a) side of the flow path switching valve (V1, V2), ) includes a first port (P1) connected to the first flow path (41a, 42a), a second port (P2) connected to the second flow path (41b, 42b), and an internal flow path (77). ) of the flow path switching valves (V1, V2). 76) is a rotation angle position in a first state where the first port (P1) and the second port (P2) communicate with each other via the internal flow path (77), and the first port (P1) and the second port (P2) communicate with each other. The rotation angle position is a second state in which the second port (P2) is closed.

In the eighth aspect, the electric motor (75) changes the rotation angle position of the rotating part (76), so that the electric rotary flow path switching valves (V1, V2) are switched between the first state and the second state. Can be switched.

In a ninth aspect, in the eighth aspect, the flow path switching valves (V1, V2) are configured with electric rotary three-way switching valves (71, 72) having a closed third port (P3). , the rotating part (76) of the three-way switching valve (71, 72) in the first state connects the first port (P1) and the second port (P2) via the internal flow path (77). The rotary part (76) of the three-way switching valve (71, 72) in the second state is at a rotational angle position where one of the first port (P1) and the second port (P2) communicates with the other. It communicates with the third port (P3) via the internal flow path (77), and is in a rotational angular position where the other of the first port (P1) and the second port (P2) is closed by the rotating part (76). This air conditioner is characterized by:

In the ninth aspect, the electric rotary three-way switching valve (71, 72) is switched between the first state and the second state by changing the rotation angle position of the rotating part (76) by the electric motor (75). It will be done.

In a tenth aspect, in any one of the first to ninth aspects, the flow path switching valve (V1, V2) is configured to control the refrigerant flow on the gas side of the two refrigerant flow paths (41, 42). The air conditioner is characterized in that it is connected at least to a channel (42).

In the tenth aspect, flow path switching valves (V1, V2) are connected to the gas side refrigerant flow path (42), which has a larger piping diameter than the liquid side refrigerant flow path (41). Therefore, a decrease in pressure loss in the gas-side refrigerant flow path (42) can be suppressed.

An eleventh aspect is a flow path switching valve (V1, V2) connected to the refrigerant flow path (41, 42) of the air conditioner (10) according to any one of the first to tenth aspects. This is a flow path switching valve.

FIG. 1 is a piping system diagram showing a schematic configuration of an air conditioner according to an embodiment. FIG. 2 is an enlarged circuit diagram of the cutoff unit. This shows the flow of refrigerant during normal cooling operation. FIG. 3 is an enlarged circuit diagram of the cutoff unit. This shows the flow of refrigerant during normal heating operation. FIG. 4 is an enlarged circuit diagram of the cutoff unit. This indicates a state in which refrigerant has leaked. FIG. 5 is an enlarged circuit diagram of the cutoff unit of Modification 2. FIG. 5(A) shows normal operation. FIG. 5(B) shows the state when the refrigerant leaks. FIG. 6 is an enlarged circuit diagram of the cutoff unit of Modification 3. FIG. 6(A) shows normal operation. FIG. 6(B) shows the state when the refrigerant leaks. FIG. 7 is a piping system diagram showing a schematic configuration of an air conditioner according to another first example. FIG. 8 is a piping system diagram showing a schematic configuration of an air conditioner according to another second example. FIG. 9 is a table regarding the refrigerant used in the refrigerant circuit of the air conditioner of the embodiment, each modification, and other embodiments.

Embodiments of the present disclosure will be described below with reference to the drawings. Note that the following embodiments are essentially preferable examples, and are not intended to limit the scope of the present invention, its applications, or its uses.

《Embodiment》
<Overview of air conditioner>
The air conditioner (10) of this embodiment performs air conditioning of an indoor space, which is a target space. As shown in FIG. 1, the air conditioner (10) of this example has a multi-type configuration including an outdoor unit (20) and a plurality of indoor units (30). The air conditioner (10) of this example switches between cooling and heating the target space. The number of indoor units (30) may be three or more.

The outdoor unit (20) is installed outdoors. The outdoor unit (20) constitutes a heat source unit. The outdoor unit (20) is provided with a heat source circuit (20a). Each indoor unit (30) is installed indoors. Each indoor unit (30) constitutes a utilization unit. The indoor units (30) are each provided with a utilization circuit (30a). In the air conditioner (10), an outdoor unit (20) and an indoor unit (30) are connected to each other via connecting pipes (11, 15).

The air conditioner (10) includes a refrigerant circuit (10a). The refrigerant circuit (10a) is filled with refrigerant. In the refrigerant circuit (10a), a vapor compression type refrigeration cycle is performed by circulating refrigerant. The refrigerant circuit (10a) includes a heat source circuit (20a) of the outdoor unit (20) and a plurality of utilization circuits (30a) of each indoor unit (30). In the refrigerant circuit (10a), a plurality of utilization circuits (30a) are connected in parallel to each other. The heat source circuit (20a) and the plurality of utilization circuits (30a) are connected via connecting pipes (11, 15).

<Connection piping>
The communication pipe includes a liquid communication pipe (11) and a gas communication pipe (15).

The liquid communication pipe (11) includes a main liquid pipe (12) and a plurality of liquid branch pipes (13). One end of the liquid communication pipe (11) is connected to the liquid shutoff valve (25) of the heat source circuit (20a). One end of the liquid branch pipe (13) is connected to the main liquid pipe (12). The other end of the liquid branch pipe (13) is connected to the liquid end (liquid side joint) of the utilization circuit (30a).

The gas communication pipe (15) includes a main gas pipe (16) and a plurality of gas branch pipes (17). One end of the gas communication pipe (15) is connected to the gas shutoff valve (26) of the heat source circuit (20a). One end of the gas branch pipe (17) is connected to the main gas pipe (16). The other end of the gas branch pipe (17) is connected to the gas end (gas side joint) of the utilization circuit (30a).

The liquid branch pipe (13) constitutes a liquid refrigerant flow path (41) connected to the liquid end of the utilization circuit (30a). The gas branch pipe (17) constitutes a gas refrigerant flow path (42) connected to the gas end of the utilization circuit (30a). The pipe diameter of the gas refrigerant flow path (42) is larger than the pipe diameter of the liquid refrigerant flow path (41). The outer diameter of the piping of the gas refrigerant flow path (42) is, for example, 12.7 mm or 15.9 mm.

<Outdoor unit>
As shown in FIG. 1, the air conditioner (10) includes one outdoor unit (20). The outdoor unit (20) includes a casing (not shown) that accommodates a heat source circuit (20a). The heat source circuit (20a) includes a compressor (21), an outdoor heat exchanger (22), an outdoor four-way switching valve (23), an outdoor expansion valve (24), a gas closing valve (26), and a liquid closing valve (25). ) are connected. The compressor (21) compresses the sucked refrigerant and discharges the compressed refrigerant. The outdoor heat exchanger (22) constitutes a heat source heat exchanger that exchanges heat between the refrigerant and outdoor air. An outdoor fan (22a) is provided near the outdoor heat exchanger (22). The outdoor fan (22a) transports outdoor air passing through the outdoor heat exchanger (22).

The outdoor four-way switching valve (23) switches between a first state shown by a solid line in FIG. 1 and a second state shown by a broken line in FIG. The outdoor four-way switching valve (23) in the first state communicates the discharge side of the compressor (21) with the gas end of the outdoor heat exchanger (22), and communicates the suction side of the compressor (21) with the gas shutoff valve. (26). The outdoor four-way switching valve (23) in the second state communicates the discharge side of the compressor (21) with the gas shutoff valve (26), and communicates the suction side of the compressor (21) with the outdoor heat exchanger (22). communicate with the gas end of the

The outdoor expansion valve (24) is connected between the outdoor heat exchanger (22) and the liquid shutoff valve (25) in the heat source circuit (20a). The outdoor expansion valve (24) is an electronic expansion valve whose opening degree can be adjusted.

The outdoor unit (20) is provided with an outdoor controller (27). The outdoor controller (27) controls components of the outdoor unit (20) including the compressor (21), outdoor expansion valve (24), and outdoor fan (22a). The outdoor controller (27) includes a microcomputer mounted on a control board and a memory device (specifically, a semiconductor memory) that stores software for operating the microcomputer.

<Indoor unit>
As shown in FIG. 1, the air conditioner (10) includes a plurality of indoor units (30). The indoor unit (30) is configured to be installed on the ceiling. The ceiling-mounted type herein includes a ceiling-embedded type and a ceiling-suspended type. The outdoor unit (20) includes a casing (not shown) that accommodates the utilization circuit (30a). An indoor heat exchanger (31) and an indoor expansion valve (32) are connected to the utilization circuit (30a). The indoor heat exchanger (31) constitutes a utilization heat exchanger that exchanges heat between the refrigerant and indoor air. An indoor fan (31a) is provided near the indoor heat exchanger (31). The indoor fan (31a) transports indoor air passing through the indoor heat exchanger (31).

The indoor expansion valve (32) is connected between the liquid side joint and the indoor heat exchanger (31) in the utilization circuit (30a). The indoor expansion valve (32) is an electronic expansion valve whose opening degree can be adjusted.

The indoor unit (30) is provided with an indoor controller (33). The indoor controller (33) controls the components of the indoor unit (30), including the indoor expansion valve (32) and the indoor fan (31a). The indoor controller (33) includes a microcomputer mounted on a control board and a memory device (specifically, a semiconductor memory) that stores software for operating the microcomputer.

A remote control (34) is connected to the indoor unit (30). By operating the remote control (34), the operating mode and temperature setting of the corresponding indoor unit (30) can be switched.

The indoor unit (30) includes an LED light (not shown). The LED light lights up when the shutoff unit (50) is opened and closed when the air conditioner (10) is in operation. It lights up in different ways when the valve is closed and when it is open. By checking the lighting state of the LED, the user can determine whether the cutoff unit (50) (strictly speaking, the flow path switching valves (V1, V2)) is open or closed.

<Refrigerant leak detection sensor>
The air conditioner (10) is equipped with a refrigerant leak detection sensor (35). One refrigerant leak detection sensor (35) of this example is provided in each indoor unit (30). The refrigerant leak detection sensor (35) of this example is arranged inside the casing of the indoor unit (30). The refrigerant leakage detection sensor (35) constitutes a detection unit that detects refrigerant leakage from the utilization circuit (30a) of the corresponding indoor unit (30). The refrigerant leak detection sensor (35) may be placed outside the casing of the indoor unit (30).

<Shutoff unit>
The air conditioner (10) includes a shutoff unit (50). The shutoff unit (50) is configured to shut off the liquid refrigerant flow path (41) and the gas refrigerant flow path (42) when refrigerant leaks in the corresponding usage circuit (30a). The shutoff unit (50) includes a liquid refrigerant flow path (41), a gas refrigerant flow path (42), a first flow path switching valve (V1), a second flow path switching valve (V2), and a high pressure introduction circuit. (60).

The first flow path switching valve (V1) is connected to the liquid refrigerant flow path (41). The first flow path switching valve (V1) constitutes a cutoff valve that shuts off the liquid refrigerant flow path (41). The second flow path switching valve (V2) is connected to the gas refrigerant flow path (42). The second flow path switching valve (V2) constitutes a cutoff valve that shuts off the gas refrigerant flow path (42). The first flow path switching valve (V1) and the second flow path switching valve (V2) are arranged outside the casing of the indoor unit (30).

The liquid refrigerant flow path (41) includes a first liquid flow path (41a) that is a first flow path and a second liquid flow path (41b) that is a second flow path. The first liquid flow path (41a) is formed on the heat source circuit (20a) side of the liquid refrigerant flow path (41). The second liquid flow path (41b) is formed on the utilization circuit (30a) side of the liquid refrigerant flow path (41).

The gas refrigerant flow path (42) includes a first gas flow path (42a) that is a first flow path and a second gas flow path (42b) that is a second flow path. The first gas flow path (42a) is formed on the heat source circuit (20a) side of the gas refrigerant flow path (42). The second gas flow path (42b) is formed on the utilization circuit (30a) side of the gas refrigerant flow path (42).

The high pressure introduction circuit (60) includes a liquid side introduction path (61), a gas side introduction path (62), and a main introduction path (63). One end of the liquid side introduction path (61) is connected to the middle of the first liquid flow path (41a). The other end of the liquid side introduction path (61) is connected to one end of the main introduction path (63). One end of the gas side introduction path (62) is connected to the middle of the second gas flow path (42b). The other end of the gas side introduction path (62) is connected to one end of the main introduction path (63). The other end side of the main introduction path (63) branches into a first branch introduction part (63a) and a second branch introduction part (63b).

A first check valve (64), which is a first on-off valve, is connected to the liquid side introduction path (61). A second check valve (65), which is a second on-off valve, is connected to the gas side introduction path (62). The first check valve (64) allows the refrigerant to flow from the liquid side introduction path (61) toward the main introduction path (63), and prohibits the refrigerant from flowing in the opposite direction. The second check valve (65) allows the refrigerant to flow from the gas side introduction path (62) toward the main introduction path (63), and prohibits the refrigerant from flowing in the opposite direction.

The first flow path switching valve (V1) of this example is comprised of a differential pressure driven first four-way switching valve (51). The second flow path switching valve (V2) of this example is comprised of a differential pressure driven second four-way switching valve (52).

As shown in FIGS. 1 and 2, each four-way switching valve (51, 52) has a first port (P1), a second port (P2), a third port (P3), and a fourth port (P4). We are prepared.

As shown in FIGS. 1 and 2, the first port (P1) of the first four-way switching valve (51) is connected to the first liquid flow path (41a). The second port (P2) of the first four-way switching valve (51) is connected to the second liquid flow path (41b). The third port (P3) of the first four-way switching valve (51) communicates with the high pressure introduction circuit (60). Strictly speaking, the third port (P3) of the first four-way switching valve (51) is connected to the first branch introduction section (63a) of the high pressure introduction circuit (60). The fourth port (P4) of the first four-way switching valve (51) is closed by the first closing member (53) (see FIG. 2).

The first port (P1) of the second four-way switching valve (52) is connected to the first gas flow path (42a). The second port (P2) of the second four-way switching valve (52) is connected to the second gas flow path (42b). The third port (P3) of the second four-way switching valve (52) communicates with the high pressure introduction circuit (60). Strictly speaking, the third port (P3) of the second four-way switching valve (52) is connected to the second branch introduction section (63b) of the high pressure introduction circuit (60). The fourth port (P4) of the second four-way switching valve (52) is closed by the second closing member (54) (see FIG. 2).

Each four-way switching valve (51, 52) is in a first state in which a first port (P1) and a second port (P2) communicate with each other, and a third port (P3) and a fourth port (P4) communicate with each other. (the state shown by the solid line in FIG. 1) and a second state (shown by the solid line in FIG. 1) in which the first port (P1) and the third port (P3) communicate with each other, and the second port (P2) and the fourth port (P4) communicate with each other 1).

As shown in FIGS. 2 to 4, the first four-way switching valve (51) has a first low pressure pipe (55). One end of the first low pressure pipe (55) is connected to the second port (P2) of the first four-way switching valve (51). The first low pressure pipe (55) communicates with the utilization circuit (30a) via the second liquid flow path (41b). The other end of the first low pressure pipe (55) is connected to a pressure chamber inside the first four-way switching valve (51).

The second four-way switching valve (52) has a second low pressure pipe (56). One end of the second low pressure pipe (56) is connected to the second port (P2) of the second four-way switching valve (52). The second low pressure pipe (56) communicates with the utilization circuit (30a) via the second gas flow path (42b). The other end of the second low pressure pipe (56) is connected to a pressure chamber inside the second four-way switching valve (52). In each of the four-way switching valves (51, 52) shown in FIGS. 2 to 4, the internal flow paths for communicating the four ports (P1, P2, P3, P4) are shown with broken lines.

The cutoff unit (50) includes a control unit (57). The control unit (57) includes a microcomputer mounted on a control board and a memory device (specifically, a semiconductor memory) that stores software for operating the microcomputer.

-Driving behavior-
The air conditioner (10) performs cooling operation and heating operation. Cooling operation and heating operation during normal operation in which no refrigerant leakage occurs will be described below with reference to FIG. 1.

<Cooling operation>
In the cooling operation, the outdoor four-way switching valve (23) is in the first state, the first four-way switching valve (51) is in the first state, and the second four-way switching valve (52) is in the first state. The outdoor expansion valve (24) is opened. The opening degree of each indoor expansion valve (32) is controlled based on the degree of superheating of the corresponding indoor heat exchanger (31). The outdoor fan (22a) and the indoor fan (31a) operate. In the cooling operation, a first refrigeration cycle (cooling cycle) is performed in which the refrigerant radiates heat and condenses in the outdoor heat exchanger (22) and evaporates in the indoor heat exchanger (31).

The refrigerant compressed by the compressor (21) radiates heat and condenses in the outdoor heat exchanger (22), and passes through the outdoor expansion valve (24). This refrigerant is branched from the main liquid pipe (12) to each liquid refrigerant flow path (41), flows sequentially through the first port (P1) and second port (P2) of the first four-way switching valve (51), and flows through each liquid refrigerant flow path (41) in order. It flows into the utilization circuit (30a). In each utilization circuit (30a), the refrigerant is depressurized by the indoor expansion valve (32) and then evaporated in the indoor heat exchanger (31). In the indoor heat exchanger (31), air is cooled by the evaporating refrigerant. The cooled air is supplied to the indoor space.

The refrigerant evaporated in each indoor heat exchanger (31) flows through each gas refrigerant flow path (42), and sequentially flows through the second port (P2) and the first port (P1) of the second four-way switching valve (52). . This refrigerant joins in the main gas pipe (16) and is sucked into the compressor (21).

<Heating operation>
In the heating operation, the outdoor four-way switching valve (23) is in the second state, the first four-way switching valve (51) is in the first state, and the second four-way switching valve (52) is in the first state. The opening degree of the outdoor expansion valve (24) is controlled based on the degree of superheating of the refrigerant flowing out of the outdoor heat exchanger (22). The opening degree of each indoor expansion valve (32) is controlled based on the degree of supercooling flowing out of the corresponding indoor heat exchanger (31). The outdoor fan (22a) and the indoor fan (31a) operate. In the heating operation, a second refrigeration cycle (heating cycle) is performed in which the refrigerant radiates heat and condenses in the indoor heat exchanger (31) and evaporates in the indoor heat exchanger (31).

The refrigerant compressed by the compressor (21) is branched from the main gas pipe (16) to each gas refrigerant flow path (42), and is then divided into the first port (P1) and the second port of the second four-way switching valve (52). (P2) and flows into each utilized circuit (30a). In each utilization circuit (30a), the refrigerant radiates heat and condenses in the indoor heat exchanger (31). In the indoor heat exchanger (31), air is heated by the refrigerant that radiates heat. The heated air is supplied to the indoor space.

The refrigerant that radiated heat in each indoor heat exchanger (31) flows through each liquid refrigerant flow path (41), and sequentially flows through the second port (P2) and the first port (P1) of the first four-way switching valve (51). . This refrigerant joins in the main liquid pipe (12) and is depressurized in the outdoor expansion valve (24). The depressurized refrigerant flows through the outdoor heat exchanger (22). In the outdoor heat exchanger (22), the refrigerant absorbs heat from the outdoor air and evaporates. The evaporated refrigerant is sucked into the compressor (21).

-Operation of flow path switching valve when refrigerant leaks-
The first four-way switching valve (51) and the second four-way switching valve (52) of this example are configured to be maintained in the above-described first state during normal operation. Specifically, for example, the spool valve inside each four-way switching valve (51, 52) is pressed by the high-pressure refrigerant introduced from the third port (P3) or a biasing means such as a spring, ) and the second port (P2), and the third port (P3) and the fourth port (P4) (see FIGS. 2 and 3). Thereby, the liquid refrigerant flow path (41), the utilization circuit (30a), and the gas refrigerant flow path (42) are communicated with each other, and the above-mentioned cooling cycle and heating operation can be performed. The valve seat portion of the spool valve is preferably made of a resin material with low sliding resistance. The resin material may be, for example, Teflon (registered trademark).

The high-pressure introduction circuit (60) of this example is configured to introduce high-pressure refrigerant into the third port (P3) during both cooling operation and heating operation.

In the cooling operation shown in FIG. 2, high-pressure liquid refrigerant flows through the liquid refrigerant flow path (41), and low-pressure gas refrigerant after pressure reduction flows through the gas refrigerant flow path (42). Therefore, in the high-pressure introduction circuit (60) during cooling operation, the high-pressure liquid refrigerant in the liquid side introduction path (61) flows through the first check valve (64) in the open state, and passes through the main introduction path (63). It is introduced into the third port (P3) of each four-way switching valve (51, 52). At this time, the second check valve (65) is basically in a closed state.

In the heating operation shown in FIG. 3, a high-pressure gas refrigerant flows through the gas refrigerant flow path (42), and a liquid refrigerant whose pressure is slightly lower than that of the gas refrigerant flows through the liquid refrigerant flow path (41). Therefore, in the high-pressure introduction circuit (60) during heating operation, the high-pressure gas refrigerant in the gas side introduction path (62) flows through the second check valve (65) in the open state, and passes through the main introduction path (63). It is introduced into the third port (P3) of each four-way switching valve (51, 52). At this time, the second check valve (65) is in a closed state or an open state.

In this way, in the cooling operation and the heating operation, the high-pressure refrigerant that serves as the driving source for each of the four-way switching valves (51, 52) can be reliably supplied to the third port (P3).

When refrigerant leaks in the utilization circuit (30a) of the indoor unit (30) during cooling or heating operation, the first four-way switching valve (51) and the second four-way switching valve (52) enter the second state. (See Figure 4). This operation blocks the liquid refrigerant flow path (41) and the gas refrigerant flow path (42). As a result, it is possible to quickly prevent the refrigerant in the heat source circuit (20a), the main liquid pipe (12), and the main gas pipe (16) from leaking from the usage circuit (30a) into the indoor space or the like.

Specifically, when refrigerant leaks in the utilization circuit (30a), the internal pressures of the utilization circuit (30a), the liquid refrigerant flow path (41), and the gas refrigerant flow path (42) decrease. In the first four-way switching valve (51), the internal pressure of the first low pressure pipe (55) decreases as the internal pressure of the liquid refrigerant flow path (41) decreases. In the first four-way switching valve (51), the spool valve moves due to the pressure difference between the high-pressure refrigerant introduced from the third port (P3) and the internal pressure of the first low-pressure pipe (55). As a result, as shown in FIG. 4, in the first four-way switching valve (51), the first port (P1) and the third port (P3) communicate with each other, and the second port (P2) and the fourth port ( P4) is in a second state where it communicates. As a result, the liquid refrigerant flow path (41) is blocked by the first four-way switching valve (51).

Similarly, in the second four-way switching valve (52), the internal pressure of the second low pressure pipe (56) decreases as the internal pressure of the gas refrigerant flow path (42) decreases. In the second four-way switching valve (52), the spool valve moves due to the pressure difference between the high-pressure refrigerant introduced from the third port (P3) and the internal pressure of the second low-pressure pipe (56). As a result, as shown in FIG. 4, in the second four-way switching valve (52), the first port (P1) and the third port (P3) communicate with each other, and the second port (P2) and the fourth port ( P4) is in a second state where it communicates. As a result, the liquid refrigerant flow path (41) is blocked by the first four-way switching valve (51).

In this way, each of the four-way switching valves (51, 52) of this embodiment automatically shuts down when refrigerant leaks in the utilization circuit (30a) by utilizing the decrease in the internal pressure of the low-pressure pipes (55, 56). Switches to 2 states. Thereby, the utilized circuit (30a) can be reliably switched to a closed circuit.

In addition, when switching the differential pressure driven four-way switching valve (51, 52) from the first state to the second state, a known pilot pipe and pilot valve may be used.

-Other actions when refrigerant leaks-
When a refrigerant leak occurs in the utilization circuit (30a), a refrigerant leak detection sensor (35) detects this refrigerant leak. When the indoor controller (33) receives a detection signal from the refrigerant leak detection sensor (35), a sign indicating this is displayed on the display section. The display section may be provided, for example, on the remote control (34) or on a decorative panel of the indoor unit (30). The display section is switched between displaying an abnormal state in which refrigerant leakage has occurred and displaying a normal state in which no refrigerant leakage has occurred.

-Effects of embodiment-
The embodiment includes a heat source circuit (20a) to which a compressor (21) and an outdoor heat exchanger (22) are connected, and a utilization circuit (30a) to which an indoor heat exchanger (31) is connected, and includes a refrigeration cycle. An air conditioner comprising a refrigerant circuit (10a) in which the heat source circuit (20a) is provided, an outdoor unit (20) in which the heat source circuit (20a) is provided, and an indoor unit (30) in which the utilization circuit (30a) is provided. , the refrigerant circuit (10a) includes refrigerant flow paths (41, 42) connected to both ends of the utilization circuit (30a), and is connected to each of the two refrigerant flow paths (41, 42). It further includes a shutoff valve, and at least one of the two shutoff valves switches the flow path to shut off the refrigerant flow path (41, 42) when a refrigerant leak occurs in the utilization circuit (30a). It consists of road switching valves (V1, V2).

The cutoff valves for the liquid refrigerant flow path (41) and the gas refrigerant flow path (42) are configured with flow path switching valves (V1, V2). Due to their structure, the flow path switching valves (V1, V2) have relatively wide flow paths compared to electromagnetic valves and expansion valves. In cooling operation and heating operation, pressure loss can be reduced when the refrigerant passes through the flow path switching valves (V1, V2). Therefore, power consumption of the air conditioner (10) can be reduced. When refrigerant leaks, the flow of refrigerant can be cut off by switching the flow paths of the flow path switching valves (V1, V2).

In the embodiment, the refrigerant flow path (41, 42) is connected to a first flow path (41a, 42a) formed on the heat source circuit (20a) side of the flow path switching valve (V1, V2), a second flow path (41b, 42b) formed on the utilization circuit (30a) side of the path switching valve (V1, V2), the flow path switching valve (V1, V2) includes a second flow path (41b, 42b) formed on the utilization circuit (30a) side; (41a, 42a), a second port (P2) connected to the second flow path (41b, 42b), a third port (P3), and a fourth port (P4). ) and is composed of four-way switching valves (51, 52).

The flow path switching valves (V1, V2) are composed of four-way switching valves (51, 52). Due to its structure, the four-way switching valve (51, 52) has a relatively wide flow path compared to a solenoid valve or an expansion valve. In cooling operation and heating operation, pressure loss can be reduced when the refrigerant passes through the flow path switching valves (V1, V2). Therefore, power consumption of the air conditioner (10) can be reduced. As described above, the four-way switching valves (51, 52) are connected to a pipe having an outer diameter of 12.7 mm or 15.9 mm. Generally, pipes having the same outer diameter may be connected to the outdoor four-way switching valve (23) of the multi-type air conditioner (10) as well. In the embodiment, the same valve used as the outdoor four-way switching valve (23) can be used as the four-way switching valve (51, 52). Furthermore, the amount of refrigerant leaking when the valve is closed can be reduced compared to when a solenoid valve or an expansion valve is used as a cutoff valve and connected to a pipe having an outer diameter of 12.7 mm or 15.9 mm.

In the embodiment, the refrigerant circuit (10a) includes a high-pressure introduction circuit (60) that introduces the high-pressure refrigerant in the first flow path (41a, 42a) to the third port (P3), and the four-way switching valve ( 51, 52) are differential pressure drive types whose driving source is the high-pressure refrigerant introduced into the third port (P3).

The high-pressure refrigerant in the first flow path (41a, 42a) is introduced into the third port (P3) of the four-way switching valve (51, 52). The state of the four-way switching valve (51, 52) can be switched using the pressure of this high-pressure refrigerant. Thereby, the refrigerant flow path (41, 42) can be shut off without using another drive source such as an electric motor.

In the embodiment, the refrigerant circuit (10a) includes a first refrigeration cycle (cooling cycle) in which the outdoor heat exchanger (22) serves as a radiator and the indoor heat exchanger (31) serves as an evaporator; The exchanger (31) is configured to perform a second refrigeration cycle (heating cycle) in which the exchanger (31) serves as a radiator and the outdoor heat exchanger (22) serves as an evaporator, and the high pressure introduction circuit (60) The high-pressure refrigerant in the first flow path (41a, 42a) having a high pressure among the first flow paths (41a, 42a) of the refrigerant flow path (41, 42) is introduced into at least the third port (P3). It is composed of

With this configuration, high-pressure refrigerant can be reliably introduced into the third port (P3) of the four-way switching valve (51, 52) in both the cooling operation and the heating operation. Thereby, the four-way switching valves (51, 52) can be reliably switched using the pressure of this high-pressure refrigerant.

In the embodiment, the high pressure introduction circuit (60) includes a liquid side introduction path (61) that connects the first liquid flow path (41a) and the third port (P3) of the liquid refrigerant flow path (41), and a gas The liquid side introduction path (61) includes a gas side introduction path (62) that communicates the first gas flow path (41b) and the third port (P3) of the refrigerant flow path (42), and the liquid side introduction path (61) includes A first check valve (64) that is opened during the first refrigeration cycle is provided, and a second check valve (65) that is opened during the second refrigeration cycle is provided in the gas side introduction path (62).

In this configuration, when the pressure in the liquid refrigerant flow path (41) increases during the first refrigeration cycle (cooling cycle), the first check valve (64) is opened and high-pressure refrigerant is introduced into the third port (P3). be done. When the pressure in the gas refrigerant flow path (42) increases during the second refrigeration cycle (heating cycle), the second check valve (65) is opened and high-pressure refrigerant is introduced into the third port (P3).

In the embodiment, the four-way switching valve (51, 52) has a closed fourth port (P4), and the four-way switching valve (51, 52) in the first state has the first port (P1) and the fourth port (P4) closed. The four-way switching valve (51, 52) in the second state communicates with the first port (P1) by communicating with the second port (P2) and communicating with the third port (P3) and the fourth port (P4). The third port (P3) is brought into communication with the third port (P3), and the second port (P2) and the fourth port (P4) are brought into communication with each other.

In this configuration, when the four-way switching valve (51, 52) enters the first state, the first port (P1) and the second port (P2) communicate with each other, and the refrigerant flow path (41, 42) becomes conductive. In this state, cooling operation and heating operation are performed. When the four-way switching valve (51, 52) enters the second state, the second port (P2) and the closed fourth port (P4) communicate with each other. In this state, the liquid refrigerant flow path (41) and the gas refrigerant flow path (42) are cut off, and the utilization circuit (30a) is separated from the refrigerant circuit (10a).

In the embodiment, the four-way switching valve (51, 52) has a low pressure pipe (55, 56) communicating with the utilization circuit (30a), and the high pressure refrigerant and the internal pressure of the low pressure pipe (55, 56) are connected to each other. The pressure difference switches to the second state.

When the refrigerant in the utilization circuit (30a) leaks, the internal pressure of the utilization circuit (30a) decreases. Accordingly, the internal pressure of the low pressure pipes (55, 56) decreases. In the four-way switching valves (51, 52), the pressure difference between the high-pressure refrigerant and the internal pressure of the low-pressure pipes (55, 56) increases, and the four-way switching valves (51, 52) in the first state switch to the second state. The four-way switching valves (51, 52) automatically switch to the second state in response to leakage of refrigerant in the utilization circuit (30a).

In the embodiment, the flow path switching valve (V1, V2) is connected to at least the gas refrigerant flow path (42) of the two refrigerant flow paths (41, 42). The pipe diameter of the gas refrigerant flow path (42) is larger than the pipe diameter of the liquid refrigerant flow path (41). Therefore, by providing the flow path switching valves (V1, V2) in the gas refrigerant flow path (42), it is possible to effectively suppress the increase in pressure loss caused by the shield valve.

<Modification 1>
In the above embodiment, the first check valve (64), which is the first on-off valve, is provided in the liquid side introduction path (61) of the high pressure introduction circuit (60). A second check valve (65), which is a second on-off valve, is provided in the gas side introduction path (62) of the high pressure introduction circuit (60). In Modification 1, the first on-off valve is configured with a first electromagnetic on-off valve instead of the first check valve (64). Instead of the second check valve (65), the second on-off valve is constituted by a second electromagnetic on-off valve. The first electromagnetic on-off valve is opened during the first refrigeration cycle (cooling cycle) and closed during the second refrigeration cycle (heating cycle). The second electromagnetic on-off valve is closed during the first refrigeration cycle (cooling cycle) and closed during the second refrigeration cycle (heating cycle). Thereby, as in the above embodiment, high-pressure refrigerant can be introduced into the third port (P3) of the four-way switching valve (51, 52) in both the cooling operation and the heating operation.

<Modification 2>
Modification 2 shown in FIG. 5 differs from the above embodiment in the configuration of the cutoff unit (50). The cutoff valve of the cutoff unit (50) is composed of a three-way switching valve (71, 72). The three-way switching valves (71, 72) of this example are electrically rotary so-called rotary valves.

A first three-way switching valve (71) is connected to the liquid refrigerant flow path (41). A second three-way switching valve (72) is connected to the gas refrigerant flow path (42). Each three-way switching valve (71, 72) has a first port (P1), a second port (P2), and a third port (P3).

The first port (P1) of the first three-way switching valve (71) is connected to the first liquid flow path (41a). The second port (P2) of the first three-way switching valve (71) is connected to the second liquid flow path (41b). The third port (P3) of the first three-way switching valve (71) is closed by the third closing member (83). The first port (P1) of the second three-way switching valve (72) is connected to the first gas flow path (42a). The second port (P2) of the second three-way switching valve (72) is connected to the second gas flow path (42b). The third port (P3) of the second three-way switching valve (72) is closed by the fourth closing member (84).

Each three-way switching valve (71, 72) includes an electric motor (75), a rotating part (76) rotationally driven by the electric motor (75), and a case (78) that accommodates the rotating part (76). . The case (78) is formed with the above-described first port (P1), second port (P2), and third port (P3). An internal flow path (77) is formed in the rotating part (76). The internal flow path (77) in this example has a substantially L-shape when viewed from a cross section perpendicular to the axis.

Each three-way switching valve (71, 72) is switched between a first state in which the refrigerant flow path (41, 42) is made conductive and a second state in which the refrigerant flow path (41, 42) is cut off.

During normal operation (cooling operation and heating operation) shown in FIG. 5(A), each three-way switching valve (71, 72) is controlled to the first state by the control unit (57). The control unit (57) controls the electric motor (75) so that each three-way switching valve (71, 72) is in the first state. The rotating part (76) of each three-way switching valve (71, 72) in the first state is at a rotational angular position that communicates the first port (P1) and the second port (P2) via the internal flow path (77). becomes. Thereby, in the cooling operation and the heating operation, the refrigerant flows through the liquid refrigerant flow path (41) and the gas refrigerant flow path (42).

When refrigerant leaks in the utilization circuit (30a) and the refrigerant leak detection sensor (35) detects the refrigerant leak, a signal is output from the indoor controller (33) to the control unit (57). As shown in FIG. 5(B), the control unit (57) receiving this signal switches each three-way switching valve (71, 72) to the second state. The control unit (57) controls the electric motor (75) so that each three-way switching valve (71, 72) is in the second state. The rotating part (76) of each three-way switching valve (71, 72) in the second state is at a rotation angle position that communicates the first port (P1) and the third port (P3) via the internal flow path (77). becomes. As a result, in the event of a refrigerant leak, the second port (P2) is substantially closed and the utilization circuit (30a) is separated from the refrigerant circuit (10a).

In modification 2, the flow path switching valve (V1, V2) is connected to a first port (P1) connected to the first flow path (41a, 42a) and to the second flow path (41b, 42b). It is an electric rotary type having a second port (P2) that rotates, a rotating part (76) in which an internal flow path (77) is formed, and an electric motor (75) that rotationally drives the rotating part (76). The rotating portion (76) of the flow path switching valve (V1, V2) is in a first state in which the first port (P1) and the second port (P2) communicate with each other via the internal flow path (77). and a rotational angular position of a second state in which the first port (P1) and the second port (P2) are closed.

The electric rotary flow path switching valves (V1, V2) have wider flow paths than electromagnetic valves and motorized valves. Therefore, the pressure loss of the shutoff valve can be reduced.

In Modification 2, the refrigerant flow path (41, 42) includes a first flow path (41a, 42a) formed on the heat source circuit (20a) side of the flow path switching valve (V1, V2); a second flow path (41b, 42b) formed on the usage circuit (30a) side of the flow path switching valve (V1, V2), and the flow path switching valve (V1, V2) It is composed of an electric rotary three-way switching valve (71, 72) having three ports (P3), and the rotating part (76) of the three-way switching valve (71, 72) in the first state is connected to the internal flow path. (77), the rotation angle position is such that the first port (P1) and the second port (P2) communicate with each other, and the rotating portion (76) of the three-way switching valve (71, 72) is in the second state. ), one of the first port (P1) and the second port (P2) communicates with the third port (P3) via the internal flow path (77), and the first port (P1) and the second port The other of the two ports (P2) is at the rotational angle position where it is closed by the rotating part (76).

With this configuration, the three-way switching valve (71, 72) can switch between conducting the refrigerant flow path (41, 42) and blocking the refrigerant flow path (41, 42).

In addition, in the three-way switching valve (71, 72), in the second state, the first port (P1) and the closed third port (P3) communicate with each other, and the second port (P2) communicates with the rotating part (76). ) may be occluded by the surface. Also in this configuration, the refrigerant flows through the refrigerant flow path (41, 42) during cooling operation and heating operation, and in the event of refrigerant leakage, the utilization circuit (30a) can be separated from the refrigerant circuit (10a).

<Modification 3>
Modification 3 shown in FIG. 6 differs from the above embodiment in the configuration of the cutoff unit (50). The cutoff valve of the cutoff unit (50) is composed of a two-way switching valve (81, 82). The two-way switching valves (81, 82) of this example are electrically rotary so-called rotary valves.

A first two-way switching valve (81) is connected to the liquid refrigerant flow path (41). A second two-way switching valve (82) is connected to the gas refrigerant flow path (42). Each two-way switching valve (81, 82) has a first port (P1) and a second port (P2).

The first port (P1) of the first two-way switching valve (81) is connected to the first liquid flow path (41a). The second port (P2) of the first two-way switching valve (81) is connected to the second liquid flow path (41b). The first port (P1) of the second two-way switching valve (82) is connected to the first gas flow path (42a). The second port (P2) of the second two-way switching valve (82) is connected to the second gas flow path (42b). The third port (P3) of the second two-way switching valve (82) is closed by the fourth closing member (84).

Each two-way switching valve (81, 82) includes an electric motor (75), a rotating part (76) rotationally driven by the electric motor (75), and a case (78) that houses the rotating part (76). have The above-described first port (P1) and second port (P2) are formed in the case (78). An internal flow path (77) is formed in the rotating part (76). The internal flow path (77) in this example has a linear shape when viewed from a cross section perpendicular to the axis.

Each two-way switching valve (81, 82) is switched between a first state in which the refrigerant flow path (41, 42) is made conductive and a second state in which the refrigerant flow path (41, 42) is cut off.

During normal operation (cooling operation and heating operation) shown in FIG. 6(A), each two-way switching valve (81, 82) is controlled to the first state by the control unit (57). The control unit (57) controls the electric motor (75) so that each two-way switching valve (81, 82) is in the first state. The rotating part (76) of each two-way switching valve (81, 82) in the first state has a rotation angle that allows communication between the first port (P1) and the second port (P2) via the internal flow path (77). position. Thereby, in the cooling operation and the heating operation, the refrigerant flows through the liquid refrigerant flow path (41) and the gas refrigerant flow path (42).

When refrigerant leaks in the utilization circuit (30a) and the refrigerant leak detection sensor (35) detects the refrigerant leak, a signal is output from the indoor controller (33) to the control unit (57). As shown in FIG. 6(B), the control unit (57) receiving this signal switches each two-way switching valve (81, 82) to the second state. The control unit (57) controls the electric motor (75) so that each two-way switching valve (81, 82) is in the second state. The rotating part (76) of each two-way switching valve (81, 82) in the second state is at a rotation angle position where the first port (P1) and the second port (P2) are closed by the rotating part (76). . In this example, the internal flow path (77) is perpendicular to the first port (P1) and the second port (P2). As a result, in the event of a refrigerant leak, the first port (P1) and the second port (P2) are blocked by the surface of the rotating part (76). The utilization circuit (30a) is separated from the refrigerant circuit (10a).

The two-way switching valve may be a ball valve type applied to water piping and the like.

<Modification 4>
The electric rotary flow path switching valve may be a four-way switching valve having four ports. In this case, for example, two ports of the four-way switching valve are closed by the closing member. The four-way switching valve switches between a first state in which the first port (P1) and the second port (P2) communicate with each other and a state in which the second port (P2) is closed.

《Other embodiments》
As shown in FIG. 7, in the air conditioner (10), a plurality of indoor units (30) may be connected in parallel to a pair of refrigerant channels (41, 42). Strictly speaking, a plurality of utilization circuits (30a) may be connected in parallel to a set of liquid refrigerant flow path (41) and gas refrigerant flow path (42).

As shown in FIG. 8, in the air conditioner (10), the heat source circuit (20a) of one outdoor unit (20) and the usage circuit (30a) of one indoor unit (30) are connected to a liquid communication pipe. (11) and the gas communication pipe (15) may be connected to each other. In other words, the air conditioner (10) may be of a so-called pair type. In this configuration, the liquid communication pipe (11) forms a liquid-side refrigerant flow path (41), and the gas communication pipe (15) forms a gas-side refrigerant flow path (42).

The indoor unit (30) is not limited to a ceiling-mounted type, but may be of other types such as a wall-mounted type or a floor-mounted type.

The flow path switching valves (V1, V2) in the above-described embodiment and each modification may be combined in any pattern. The flow path switching valve of the present disclosure may be used in only one of the two refrigerant flow paths (41, 42), and a solenoid valve or an expansion valve may be used in the other.

<About refrigerant>
The refrigerant used in the refrigerant circuit (10a) of the air conditioner (10) according to the above embodiment, each modification, and other embodiments is a flammable refrigerant. Here, the flammable refrigerant is based on the American ASHRAE34 Designation and Safety Classification of Refrigerants or the ISO817 Refrigerants-Designation and Safety Classification of Refrigerants. Classification standards include Class 3 (strong flammability), Class 2 (weak flammability), and Subclass 2L ( Contains refrigerants classified as mildly flammable. A specific example of the refrigerant used in the above embodiment and each modification is shown in FIG. In Figure 9, "ASHRAE Number" is the Ashley number of the refrigerant defined by ISO817, "component" is the Ashley number of the substance contained in the refrigerant, and "mass%" is the mass percent concentration of each substance contained in the refrigerant. , "Alternative" indicates the name of a refrigerant substance that is often substituted by the refrigerant. In this embodiment, the refrigerant used is R32. Note that the refrigerant illustrated in FIG. 9 has a characteristic that it has a higher density than air.

Although the embodiments and modifications have been described above, it will be understood that various changes in form and details can be made without departing from the spirit and scope of the claims. In addition, the above embodiments, modifications, and other embodiments may be combined or replaced as appropriate, as long as the functionality of the object of the present disclosure is not impaired. The descriptions of “first,” “second,” “third,” etc. mentioned above are used to distinguish the words to which these descriptions are given, and even the number and order of the words are limited. It's not something you do.

The present disclosure is useful for air conditioners and flow path switching valves.

10 Air conditioner 10a Refrigerant circuit 20 Outdoor unit (heat source unit)
20a Heat source circuit 21 Compressor 22 Outdoor heat exchanger (heat source heat exchanger)
30 Indoor unit (Used unit)
30a Usage circuit 31 Indoor heat exchanger (usage heat exchanger)
41 Refrigerant flow path 42 Refrigerant flow path 41a, 42a First flow path 41b, 42b Second flow path 51, 52 Four-way switching valve 55, 56 Low pressure pipe 60 High pressure introduction circuit 61 Liquid side introduction path 62 Gas side introduction path 62 Gas side Introduction path 64 First check valve (first opening/closing valve)
65 Second check valve (second on-off valve)
71, 72 Three-way switching valve 75 Electric motor 76 Rotating part 77 Internal channels V1, V2 Channel switching valve

Claims (11)

A refrigerant in which a refrigeration cycle is performed, including a heat source circuit (20a) to which a compressor (21) and a heat source heat exchanger (22) are connected, and a utilization circuit (30a) to which a utilization heat exchanger (31) is connected. An air conditioner comprising a circuit (10a),
The refrigerant circuit (10a) includes refrigerant flow paths (41, 42) respectively connected to both ends of the utilization circuit (30a),
further comprising a shutoff valve connected to each of the two refrigerant flow paths (41, 42),
At least one of the two cutoff valves is a flow path switching valve (V1, V2) that switches the flow path to shut off the refrigerant flow path (41, 42) when refrigerant leaks in the usage circuit (30a). ) consists of
The refrigerant flow path (41, 42) includes a first flow path (41a, 42a) formed on the heat source circuit (20a) side of the flow path switching valve (V1, V2), and a first flow path (41a, 42a) formed on the heat source circuit (20a) side of the flow path switching valve (V1, V2). a second flow path (41b, 42b) formed on the utilization circuit (30a) side in V1, V2),
The flow path switching valves (V1, V2) have a first port (P1) connected to the first flow path (41a, 42a) and a second port (P1) connected to the second flow path (41b, 42b). P2), a third port (P3), and a fourth port (P4), and a state in which the first port (P1) and the second port (P2) communicate with each other, and a state in which the first port (P1) and the second port (P2) communicate with each other. An air conditioner characterized by comprising a four-way switching valve (51, 52) that switches between a state in which a second port (P2) is cut off. In claim 1,
The refrigerant circuit (10a) includes a high-pressure introduction circuit (60) that introduces the high-pressure refrigerant in the first flow path (41a, 42a) to the third port (P3),
The air conditioner is characterized in that the four-way switching valve (51, 52) is a differential pressure drive type driven by a high-pressure refrigerant introduced into the third port (P3). In claim 2,
The refrigerant circuit (10a) includes a first refrigeration cycle in which the heat source heat exchanger (22) is a radiator and the utilization heat exchanger (31) is an evaporator, and the utilization heat exchanger (31) is a radiator. and a second refrigeration cycle using the heat source heat exchanger (22) as an evaporator,
The high-pressure introduction circuit (60) at least supplies the high-pressure refrigerant in the first flow path (41a, 42a) having a higher pressure among the first flow paths (41a, 42a) of the two refrigerant flow paths (41, 42). An air conditioner characterized in that the air conditioner is configured to introduce into the third port (P3). In claim 3,
The high voltage introduction circuit (60) is
a liquid-side introduction path (61) that communicates the first flow path (41a, 42a) of the refrigerant flow path (41) on the liquid side with the third port (P3);
a gas side introduction path (62) that communicates the first flow path (41a, 42a) of the refrigerant flow path (42) on the gas side with the third port (P3);
The liquid side introduction path (61) is provided with a first on-off valve (64) that is opened during the first refrigeration cycle,
The air conditioner is characterized in that the gas side introduction path (62) is provided with a second on-off valve (65) that is opened during the second refrigeration cycle. In any one of claims 1 to 4,
The four-way switching valve (51, 52) has a closed fourth port (P4),
The four-way switching valve (51, 52) in the first state allows communication between the first port (P1) and the second port (P2) and communication between the third port (P3) and the fourth port (P4). ,
The four-way switching valve (51, 52) in the second state communicates between the first port (P1) and the third port (P3) and communicates between the second port (P2) and the fourth port (P4). An air conditioner characterized by: In any one of claims 1 to 5,
The four-way switching valve (51, 52) has a low-pressure pipe (55, 56) that communicates with the utilization circuit (30a), and the four-way switching valve (51, 52) has a low-pressure pipe (55, 56) that communicates with the utilization circuit (30a). An air conditioner characterized by switching between two states. In any one of claims 1 to 6,
The air conditioner is characterized in that the four-way switching valve (51, 52) switches the flow path so as to block the refrigerant flow path (41, 42) as the spool valve moves. A refrigerant in which a refrigeration cycle is performed, including a heat source circuit (20a) to which a compressor (21) and a heat source heat exchanger (22) are connected, and a utilization circuit (30a) to which a utilization heat exchanger (31) is connected. An air conditioner comprising a circuit (10a),
The refrigerant circuit (10a) includes refrigerant flow paths (41, 42) respectively connected to both ends of the utilization circuit (30a),
further comprising a shutoff valve connected to each of the two refrigerant flow paths (41, 42),
At least one of the two cutoff valves is a flow path switching valve (V1, V2) that switches the flow path to shut off the refrigerant flow path (41, 42) when refrigerant leaks in the usage circuit (30a). ) consists of
The refrigerant flow path (41, 42) includes a first flow path (41a, 42a) formed on the heat source circuit (20a) side of the flow path switching valve (V1, V2), and a first flow path (41a, 42a) formed on the heat source circuit (20a) side of the flow path switching valve (V1, V2). a second flow path (41b, 42b) formed on the utilization circuit (30a) side in V1, V2),
The flow path switching valves (V1, V2) have a first port (P1) connected to the first flow path (41a, 42a) and a second port (P1) connected to the second flow path (41b, 42b). P2), a rotating part (76) in which an internal flow path (77) is formed, and an electric motor (75) that rotationally drives the rotating part (76),
The rotating part (76) of the flow path switching valve (V1, V2) is configured to connect the first port (P1) and the second port (P2) through the internal flow path (77). and a rotational angular position of a second state in which the first port (P1) and the second port (P2) are closed ,
The flow path switching valves (V1, V2) are composed of electric rotary three-way switching valves (71, 72) having a closed third port (P3),
The rotating part (76) of the three-way switching valve (71, 72) in the first state connects the first port (P1) and the second port (P2) via the internal flow path (77). This is the rotational angle position for communication,
The rotating part (76) of the three-way switching valve (71, 72) in the second state has one of the first port (P1) and the second port (P2) connected through the internal flow path (77). and communicates with the third port (P3), and the other of the first port (P1) and the second port (P2) is in a rotational angular position where it is closed by the rotating part (76).
An air conditioner characterized by: In claim 8 ,
A control unit (57) that switches the flow path switching valves (V1, V2) at the rotational angular position of the first state to the rotational angular position of the second state when a refrigerant leak occurs in the utilization circuit (30a). A flow path switching valve characterized by comprising: In any one of claims 1 to 9 ,
The air conditioner is characterized in that the flow path switching valve (V1, V2) is connected at least to the gas side refrigerant flow path (42) of the two refrigerant flow paths (41, 42). A flow path switching valve (V1, V2) connected to a refrigerant flow path (41, 42) of an air conditioner (10) according to any one of claims 1 to 10 .

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