JP2009144967A - Refrigerating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To smoothly switch each four-way switch valve in switching an operating state by switching the four-way switch valve in each of a plurality of heat source-side circuits where compressing mechanisms are in operation, in a refrigerating device where the plurality of heat source-side circuits are connected in parallel with each other in a refrigerant circuit. <P>SOLUTION: This refrigerating device 1 is provided with a control means 50 for stopping the compressing mechanism 40 of the heat source-side circuit 11 of which the switching motion is terminated, when the switching motion in the heat source-side circuit 11 excluding the heat source-side circuit 11 of which the switching motion is terminated at the last, in switching the operating state by switching motion of the four-way switch valve 20 in each of the plurality of heat source-side circuits 11 where the compressing mechanisms 40 are in operation. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a refrigeration apparatus in which a plurality of heat source side circuits are connected in parallel to each other in a refrigerant circuit.

Conventionally, a refrigeration apparatus is known in which a plurality of heat source side circuits are connected in parallel to each other in a refrigerant circuit. Patent Document 1 discloses an air conditioner in which two outdoor units are connected in parallel to a refrigerant circuit. In the refrigerant circuit of this air conditioner device, two outdoor units are connected in parallel to the main liquid line and the main gas line. A liquid pipe extending from each outdoor unit is connected to the main liquid line. A gas pipe extending from each outdoor unit is connected to the main gas line. Each outdoor unit has a state in which the discharge side of the compressor communicates with the liquid pipe so that the suction side of the compressor communicates with the gas pipe, and the discharge side of the compressor communicates with the gas pipe. There is provided a four-way switching valve for switching between the state in which the liquid pipe communicates with the liquid pipe.
JP 2000-146346 A

  By the way, in this kind of refrigeration apparatus, when there are a plurality of heat source side circuits in operation of the compression mechanism when switching the operation state, the four-way switching valve is switched in each of the plurality of heat source side circuits. The four-way switching valve is switched using a high-low pressure difference that is a pressure difference between the refrigerant discharged from the compressor and the suction refrigerant.

  However, the time required for switching the four-way switching valve is not necessarily the same for all four-way switching valves. Therefore, even if switching of all four-way switching valves starts at the same time, switching of all four-way switching valves may not end at the same time. In such a case, the high pressure side and the low pressure side are in communication with each other between the heat source side circuit where the switching of the four-way switching valve is finished and the heat source side circuit where the switching of the four-way switching valve is not finished. Become. For this reason, there is a problem that the refrigerant cannot be properly circulated in the refrigerant circuit, and the four-way switching valve that has not been switched cannot be switched smoothly.

  The present invention has been made in view of this point, and an object of the present invention is to provide a plurality of heat source side circuits in which a compression mechanism is operating in a refrigeration apparatus in which a plurality of heat source side circuits are connected in parallel to each other in a refrigerant circuit. When the operation state is switched by switching the four-way switching valve in each, the configuration is such that the switching of each four-way switching valve can be performed smoothly.

  1st invention is the several heat source side in which the compression mechanism (40) which consists of 1 or several compressor (14), the four-way selector valve (20), and the heat source side heat exchanger (15) were each provided. A plurality of heat source side circuits (11) such that the circuit (11), the use side circuit (61) provided with the use side heat exchanger (64), and the plurality of heat source side circuits (11) are parallel to each other. And a gas line (3) and a liquid line (2) constituting the refrigerant circuit (4) by connecting the circuit and the use side circuit (61), and the four-way switching valve ( 20) includes a valve body (55) driven by a pressure difference between the refrigerant discharged from the compression mechanism (40) and the suction refrigerant, and the discharge side of the compression mechanism (40) and the liquid line (2) are connected to each other. A first state in which the suction side of the compression mechanism (40) and the gas line (3) communicate with each other; a discharge side of the compression mechanism (40); and the gas line (3) Switching operation from when one of the second state where the suction side of the compression mechanism (40) and the liquid line (2) communicate with each other to switch to the other moves the valve body (55). The refrigeration apparatus (1) is configured to be performed by the above.

  The refrigeration apparatus (1) is operated in the operating state by causing the four-way switching valve (20) to perform a switching operation in each of the plurality of heat source side circuits (11) in which the compression mechanism (40) is operating. When the switching operation is completed in the heat source side circuit (11) other than the heat source side circuit (11) where the switching operation ends last when switching is performed, the compression mechanism of the heat source side circuit (11) after the switching operation is completed Control means (50) for stopping (40) is provided.

  In the first aspect of the invention, when the compression mechanism (40) switches the operating state by causing the four-way switching valve (20) to perform switching operation in each of the plurality of operating heat source side circuits (11), When the switching operation is completed in a certain heat source side circuit (11), if there is a heat source side circuit (11) for which the switching operation has not been completed, the control means (50) Stop the compression mechanism (40) of (11). That is, the low pressure side communicates with the high pressure side of the heat source side circuit (11) for which the switching operation has not been completed, and the high pressure side communicates with the low pressure side of the heat source side circuit (11) for which the switching operation has not been completed. In the heat source side circuit (11), the compression mechanism (40) is stopped. For this reason, the flow of the refrigerant discharged from the compression mechanism (40) of the heat source side circuit (11) in which the switching operation has not been completed is inhibited by the compression mechanism (40) of the heat source side circuit (11) in which the switching operation has been completed. Is avoided.

  According to a second invention, in the first invention, when the control means (50) switches the operating state by a switching operation in the plurality of heat source side circuits (11), the compression mechanism (40) However, the four-way switching valve (20) is caused to execute the switching operation so that the switching operations in the plurality of heat source side circuits (11) in operation are sequentially performed one by one.

  In the second invention, when the four-way switching valve (20) performs the switching operation in each of the plurality of heat source side circuits (11) in operation of the compression mechanism (40), the operation state is switched. The switching operation of the four-way switching valve (20) is performed one by one in order. The switching operation of the second and subsequent heat source side circuits (11) is started after completion of the previous switching operation. The switching operation of each heat source side circuit (11) is performed without overlapping the time during the switching operation.

  According to a third invention, in the first or second invention, when the control means (50) switches the operating state by a switching operation in the plurality of heat source side circuits (11), the four-way The operating capacity of the compression mechanism (40) of the heat source side circuit (11) in which the switching valve (20) is executing the switching operation, and the heat source side circuit (in which the four-way switching valve (20) has not yet performed the switching operation ( Set to a value larger than 11).

  In the third invention, when the operation state is switched by the switching operation in the plurality of heat source side circuits (11), the compression of the heat source side circuit (11) in which the four-way switching valve (20) is executing the switching operation. The operating capacity of the mechanism (40) is set to a larger value than the heat source side circuit (11) where the four-way switching valve (20) has not yet performed the switching operation. For this reason, the heat source side circuit (11) in which the four-way switching valve (20) is executing the switching operation has a greater effect than the heat source side circuit (11) in which the four-way switching valve (20) has not yet performed the switching operation. Many refrigerants circulate.

  In a fourth invention according to any one of the first to third inventions, in each of the heat source side circuits (11), the compression mechanism (40) is constituted by a plurality of compressors (14), The control means (50), when switching the operation state by the switching operation in the plurality of heat source side circuits (11), is a compression mechanism (40) of the heat source side circuit (11) that is executing the switching operation. Run all compressors (14).

  In the fourth invention, when the operation state is switched by the switching operation in the plurality of heat source side circuits (11), in the heat source side circuit (11) in which the four-way switching valve (20) is executing the switching operation, All the compressors (14) of the compression mechanism (40) are operated. When all the compressors (14) of the compression mechanism (40) are switched over by the heat source side circuit (11) provided with the compression mechanism (40), the switching operation is not yet finished. If there is a circuit (11), it is stopped.

  According to a fifth invention, in any one of the first to fourth inventions, when the control means (50) switches the operating state by a switching operation in the plurality of heat source side circuits (11). For the heat source side circuit (11) whose switching operation ends, the operation of the compression mechanism (40) is continued even after the switching operation ends.

  In the fifth aspect of the invention, when the operation state is switched by the switching operation in the plurality of heat source side circuits (11), the switching operation is completed in the heat source side circuit (11) that has finally finished the switching operation. However, the operation of the compression mechanism (40) is continued without stopping the compression mechanism (40). For this reason, even after the operation state is switched, the operation of the refrigeration apparatus (1) is continued as it is without stopping the operation of the refrigeration apparatus (1).

  According to a sixth aspect of the present invention, in the second or third aspect of the invention, the cooling operation in which the four-way switching valve (20) is set to the first state and the use side heat exchanger (64) operates as an evaporator. The four-way switching valve (20) is set to the second state and performs the defrost operation for melting the ice adhering to the use side heat exchanger (64) during the cooling operation, while the control means (50 ) When performing the defrost operation, the order of the heat source side circuit (11) for performing the switching operation is the same when switching from the cooling operation to the defrost operation and when returning from the defrost operation to the cooling operation. To do.

  In the sixth invention, when the defrost operation is performed, the order of the heat source side circuit (11) in which the four-way switching valve (20) performs the switching operation is the same when switching to the defrost operation and when returning to the cooling operation. Become. For this reason, both when switching to the defrost operation and when returning to the cooling operation, the compression mechanism (40) of the same heat source side circuit (11) is stopped.

  In a seventh aspect based on the second or third aspect, the control means (50) changes the order of the heat source side circuit (11) for performing the switching operation every time the defrost operation is performed.

  In the seventh invention, the order of the heat source side circuit (11) in which the four-way switching valve (20) performs the switching operation is changed every time the defrost operation is performed. For this reason, the compression mechanism (40) in which the operation time from the cooling operation to the cooling operation is returned is changed every time the defrost operation is performed.

  In the present invention, when switching the operation state, when the switching operation is completed in a certain heat source side circuit (11), if there is a heat source side circuit (11) for which the switching operation has not been completed, the control means ( 50) stops the compression mechanism (40) of the heat source side circuit (11) for which the switching operation has been completed, and thus is discharged from the compression mechanism (40) of the heat source side circuit (11) for which the switching operation has not been completed. It is avoided that the refrigerant flow is obstructed by the compression mechanism (40) of the heat source side circuit (11) after the switching operation is completed. For this reason, in the heat source side circuit (11) where the switching operation has not been completed, a high-low pressure difference required to move the valve body (55) of the four-way switching valve (20) is secured, and the four-way switching valve (20) Can be smoothly switched. Accordingly, when the four-way switching valve (20) performs the switching operation in each of the plurality of heat source side circuits (11) in operation of the compression mechanism (40), the four-way switching valve is switched. The switching operation of (20) can be performed smoothly.

  In the second aspect of the invention, the switching operation of each heat source side circuit (11) is performed without overlapping the time during the switching operation. Here, when the switching operation time of each heat source side circuit (11) overlaps each other, the heat source side circuit (11) of which the switching operation has been completed in the state where the heat source side circuit (11) during the switching operation exists is present. The compression mechanism (40) may be stopped. In such a case, the high / low pressure difference fluctuates temporarily due to the stop of the compression mechanism (40), so that the valve body (55) of the four-way switching valve (20) during the switching operation is affected by the fluctuation of the high / low pressure difference. End up. In contrast, in the second aspect of the invention, the switching operation times of the heat source side circuits (11) do not overlap with each other. There is no fluctuation. Therefore, the switching operation of each four-way switching valve (20) can be performed more smoothly.

  In the third aspect of the invention, the four-way switching valve (20) performs the switching operation by the refrigerant more than the heat source side circuit (11) for which the four-way switching valve (20) has not yet performed the switching operation. It distributes to the heat source side circuit (11) inside. For this reason, a relatively large amount of refrigerant flows through the four-way switching valve (20) that is performing the switching operation. By the way, as for the four-way selector valve (20), the moving speed of the valve element (55) increases as the refrigerant flow rate increases. Accordingly, in the four-way switching valve (20) that is executing the switching operation, the valve element (55) moves quickly, so that the switching operation can be completed in a relatively short time.

  Moreover, in the said 6th invention, when switching to defrost operation and returning to cooling operation, it stops from the compression mechanism (40) of the same heat-source side circuit (11). Therefore, when switching to the defrost operation and returning to the cooling operation, the order of the length of operation time of the compression mechanism (40) is the same. Here, in the refrigerating apparatus that uses the refrigerating machine oil for lubrication in the compression mechanism (40), the refrigerating machine oil flowing through the refrigerant circuit (4) returns to the operating compression mechanism (40). For this reason, between the start of switching to the defrost operation and the return to the cooling operation, the refrigerating machine oil tends to accumulate as the compression mechanism (40) has a longer operation time. In the sixth aspect of the invention, as described above, when switching to the defrost operation and returning to the cooling operation, the order of the length of operation time of the compression mechanism (40) is the same, and the switching operation is performed later. Refrigerating machine oil tends to accumulate in the heat source side circuit (11). For this reason, since it is possible to grasp to some extent that the refrigeration oil easily accumulates in the compression mechanism (40) of which heat source side circuit (11) from the start of switching to the defrost operation to the return to the cooling operation, each heat source side Management of the amount of refrigeration oil in the compression mechanism (40) of the circuit (11) can be facilitated.

  In the seventh aspect of the invention, the compression mechanism (40) in which the operation time from the cooling operation through the defrost operation to the cooling operation is extended is changed every time the defrost operation is performed. Therefore, every time the defrost operation is performed, the compression mechanism (40) in which the refrigerating machine oil easily accumulates is changed. Therefore, it is possible to avoid the concentration of refrigerating machine oil in one compression mechanism (40), and the amount of refrigerating machine oil in each compression mechanism (40) can be made uniform.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<Overall configuration of refrigeration equipment>
This embodiment is a refrigeration apparatus (1) according to the present invention. This refrigeration apparatus (1) is a refrigeration apparatus for cooling a refrigerator. As shown in FIG. 1, the refrigeration apparatus (1) includes three external units, a first external unit (10a), a second external unit (10b), and a third external unit (10c). (10a, 10b, 10c) are provided, and two in-compartment units (60a, 60b) of the first in-compartment unit (60a) and the second in-compartment unit (60b) are provided. All outside units (10) have the same configuration. All the internal units (60) have the same configuration. The numbers of the outside unit (10) and the inside unit (60) are merely examples.

  As shown in FIG. 2, each outside unit (10) accommodates an outside circuit (11) constituting a heat source side circuit. As shown in FIG. 3, each in-compartment unit (60) accommodates an in-compartment circuit (61) that constitutes a use side circuit. In this refrigeration apparatus (1), three refrigerant circuits (11) and two internal circuits (61) are connected by a liquid side communication pipe (2) and a gas side communication pipe (3) to connect a refrigerant circuit ( 4) is configured. The liquid side connecting pipe (2) constitutes a liquid line, and the gas side connecting pipe (3) constitutes a gas line. In the refrigerant circuit (4), the three external circuits (11) are connected in parallel to each other, and the two internal circuits (61) are connected in parallel to each other. In the refrigerant circuit (4), a refrigerant is circulated to perform a vapor compression refrigeration cycle.

<External circuit>
The external circuit (11) includes a compression mechanism (40), an external heat exchanger (15), a receiver (16), a supercooling heat exchanger (17), a first external expansion valve (18), a second An external expansion valve (19), a four-way switching valve (20), and an oil separator (33) are provided.

  The compression mechanism (40) includes a first compressor (14a) having a variable operating capacity, a second compressor (14b) having a fixed operating capacity, and a third compressor (14c) having a fixed operating capacity. Has been. These compressors (14a, 14b, 14c) are connected in parallel to each other.

  The first compressor (14a), the second compressor (14b), and the third compressor (14c) are all configured as fully-sealed high-pressure dome type scroll compressors. Electric power is supplied to the first compressor (14a) via an inverter. The first compressor (14a) is configured such that its operating capacity can be adjusted in stages by changing the output frequency of the inverter. The operating capacity of the first compressor (14a) is configured to be adjustable in a plurality of stages (for example, 20 stages). On the other hand, in the second compressor (14b) and the third compressor (14c), the electric motor is always operated at a constant rotational speed, and the operation capacity cannot be changed.

  Further, these compressors (14a, 14b, 14c) are all differential pressure oil supply type compressors. In each compressor (14a, 14b, 14c), the refrigerating machine oil accumulated at the bottom of the casing in the high-pressure space is pumped up by the centrifugal pump at the lower end of the rotating shaft of the motor, and the pumped refrigerating machine oil is scrolled through the oil passage in the rotating shaft. Supplied to the low pressure part of the type fluid machine. The refrigerating machine oil supplied to the low pressure part is used for lubrication of the sliding part. In these compressors (14a, 14b, 14c), the refrigeration oil is pumped by the pressure difference between the high-pressure refrigerant and the low-pressure refrigerant and by the centrifugal pump.

  One end of the first discharge pipe (21a) is disposed on the discharge side of the first compressor (14a), and one end of the second discharge pipe (21b) is disposed on the discharge side of the second compressor (14b). One end of a third discharge pipe (21c) is connected to the discharge side of (14c). The first discharge pipe (21a) has a check valve (CV1), the second discharge pipe (21b) has a check valve (CV2), and the third discharge pipe (21c) has a check valve (CV3). Each is provided. The other ends of these discharge pipes (21a, 21b, 21c) are connected to the first port (P1) of the four-way switching valve (20) via the discharge junction pipe (21). These check valves (CV1, CV2, CV3) are valves that allow only the flow of refrigerant toward the discharge junction pipe (21).

  One end of the first suction pipe (22a) is provided on the suction side of the first compressor (14a), and one end of the second suction pipe (22b) is provided on the suction side of the second compressor (14b). One end of a third suction pipe (22c) is connected to the suction side of (14c). The other ends of these suction pipes (22a, 22b, 22c) are connected to the third port (P3) of the four-way switching valve (20) via the suction junction pipe (22).

  The discharge junction pipe (21) is provided with an oil separator (33). The oil separator (33) is for separating the refrigerating machine oil from the refrigerant discharged from the compression mechanism (40). One end of an oil return pipe (34) is connected to the oil separator (33). The other end of the oil return pipe (34) branches into a first oil return pipe (34a), a second oil return pipe (34b), and a third oil return pipe (34c). Each oil return pipe (34a, 34b, 34c) is connected to an intermediate pressure compression chamber of each compressor (14a, 14b, 14c). Each oil return pipe (34a, 34b, 34c) is provided with a solenoid valve (SV1, SV2, SV3), respectively.

  The external heat exchanger (15) is a cross-fin type fin-and-tube heat exchanger. The external heat exchanger (15) constitutes a heat source side heat exchanger. In the vicinity of the external heat exchanger (15), an external fan (23) that sends external air to the external heat exchanger (15) is provided. In the external heat exchanger (15), heat is exchanged between the refrigerant and the external air.

  One end of the external heat exchanger (15) is connected to the second port (P2) of the four-way switching valve (20). The other end of the external heat exchanger (15) is connected to the top of the receiver (16) via the first liquid pipe (24). The first liquid pipe (24) is provided with a check valve (CV4) that allows only the flow of the refrigerant in the direction toward the receiver (16). The fourth port (P4) of the four-way switching valve (20) is connected to the second closing valve (13).

  The supercooling heat exchanger (17) includes a high pressure side flow path (17a) and a low pressure side flow path (17b), and the refrigerant flowing through the high pressure side flow path (17a) and the low pressure side flow path (17b) It is configured to exchange heat. This supercooling heat exchanger (17) is constituted by, for example, a plate heat exchanger.

  The inflow end of the high-pressure channel (17a) is connected to the bottom of the receiver (16). The outflow end of the high-pressure channel (17a) is connected to the first closing valve (12) via the second liquid pipe (25). The second liquid pipe (25) is provided with a check valve (CV5) that allows only the flow of refrigerant toward the first closing valve (12).

  On the other hand, the first branch pipe (26) branched from the second liquid pipe (25) on the upstream side of the check valve (CV5) is connected to the inflow end of the low pressure side flow path (17b). The first branch pipe (26) is provided with a second external expansion valve (19). The second external expansion valve (19) is an electronic expansion valve whose opening degree can be adjusted. One end of a gas injection pipe (30) for injecting a gas refrigerant into each compressor (14a, 14b, 14c) is connected to the outflow end of the low-pressure channel (17b). The other end of the gas injection pipe (30) is branched into three, and each is connected to each oil return pipe (34a, 34b, 34c).

  The receiver (16) is disposed between the external heat exchanger (15) and the supercooling heat exchanger (17), and is configured to temporarily store the refrigerant. One end of a gas vent pipe (27) is connected to the top of the receiver (16). The other end of the gas vent pipe (27) is connected to the gas injection pipe (30). The gas vent pipe (27) is provided with a solenoid valve (SV4).

  One end of the second branch pipe (28) is connected between the check valve (CV5) and the first closing valve (12) in the second liquid pipe (25). The other end of the second branch pipe (28) is connected between the check valve (CV4) and the receiver (16) in the first liquid pipe (24). The second branch pipe (28) is provided with a check valve (CV6) that allows only the flow of refrigerant toward the receiver (16). In addition, a gas feed pipe (32) having one end connected to the first discharge pipe (21a) is connected to a connection portion between the second branch pipe (28) and the first liquid pipe (24). The gas feed pipe (32) is provided with a check valve (CV7) that allows only the flow of refrigerant toward the first discharge pipe (21a).

  A third branch pipe (29) is connected between the first liquid pipe (24) and the first branch pipe (26). One end of the third branch pipe (29) is connected between the external heat exchanger (15) and the check valve (CV4) in the first liquid pipe (24). The other end of the third branch pipe (29) is connected to the second liquid pipe (25) side of the second branch expansion valve (19) in the first branch pipe (26). The third branch pipe (29) is provided with a first outside expansion valve (18). The first external expansion valve (18) is an electronic expansion valve whose opening degree can be adjusted.

  The four-way selector valve (20) switches between a cooling operation that cools the interior of the internal unit (60) and a defrost operation that melts frost adhering to the internal heat exchanger (64) during the cooling operation. Is for doing. The four-way selector valve (20) is in a first state in which the first port (P1) and the second port (P2) communicate with each other and the third port (P3) and the fourth port (P4) communicate with each other (FIG. 1). And a second state (FIG. 1) in which the first port (P1) and the fourth port (P4) communicate with each other and the second port (P2) and the third port (P3) communicate with each other. (State indicated by a broken line).

  In the first state, the discharge side of the compression mechanism (40) and the liquid side communication pipe (2) communicate with each other via the external heat exchanger (15), and the suction side of the compression mechanism (40) communicates with the gas side. The pipe (3) communicates. In the second state, the discharge side of the compression mechanism (40) communicates with the gas side communication pipe (3), and the suction side of the compression mechanism (40) and the liquid side communication pipe (2) communicate with each other. Communicate via (15).

  Specifically, as shown in FIG. 4, the four-way selector valve (20) includes a valve body (53) and a pilot valve (54). The valve body (53) includes a sealed cylindrical casing (56), a valve body (55) slidably provided inside the casing (56), and a piston (57) coupled to the valve body (55). And. Cylinder chambers (48, 49) are formed at both ends of the casing (56) by being partitioned by a piston (57). A first port (P1) is provided at the upper part of the casing (56). Three ports are provided in the lower part of the casing (56). The left port in FIG. 4 is the second port (P2), the middle port is the third port (P3), and the right port is the fourth port (P4).

  The pilot valve (54) includes an electromagnetic coil and a plunger inserted into the hollow portion of the electromagnetic coil. The pilot valve (54) is configured to switch the communication state of the three gas pipes (41, 42, 43) depending on whether the electromagnetic coil is energized. Of the three gas pipes (41, 42, 43), the first gas pipe (41) on the left side in FIG. 4 is connected to the cylinder chamber (48) on the left side of the casing (56) with the second gas pipe ( 42) is connected to the third port (P3), and the right third gas pipe (43) is connected to the cylinder chamber (49) on the right side of the casing (56).

  In the four-way switching valve (20), when the first gas pipe (41) and the second gas pipe (42) are communicated with each other by the pilot valve (54), the left cylinder chamber (48) and the third port (P3) Communicate. When the left cylinder chamber (48) and the third port (P3) communicate with each other, the suction refrigerant of the compression mechanism (40) flows into the left cylinder chamber (48) in the first gas pipe (41) and the second gas. It is introduced through the pipe (42). The left cylinder chamber (48) is a low pressure space. On the other hand, the refrigerant discharged from the compression mechanism (40) flowing into the high pressure chamber (47) between the pistons (57) is introduced into the right cylinder chamber (49) through a bleed hole provided in the piston (57). The The right cylinder chamber (49) is a high-pressure space. The valve body (55) moves to the left side together with the piston (57).

  On the other hand, when the second gas pipe (42) and the third gas pipe (43) are communicated with each other by the pilot valve (54), the right cylinder chamber (49) and the third port (P3) communicate with each other, The cylinder chamber (49) becomes a low pressure space, while the left cylinder chamber (48) becomes a high pressure space. The valve body (55) moves to the right side together with the piston (57). Thus, the four-way selector valve (20) is configured such that the valve element (55) is driven by the pressure difference between the refrigerant discharged from the compression mechanism (40) and the suction refrigerant (hereinafter referred to as “high / low pressure difference”). Has been. In the four-way switching valve (20), a switching operation is performed until the switching from one of the first state and the second state to the other by the movement of the valve body (55).

  The external circuit (11) is provided with a high pressure sensor (35) and a low pressure sensor (36). The high pressure sensor (35) is provided at the upstream end of the discharge junction pipe (21). The low pressure sensor (36) is provided at the downstream end of the suction junction pipe (22). Detection values of the high pressure sensor (35) and the low pressure sensor (36) are input to a controller (50) described later.

  In the external circuit (11), high pressure switches (38a, 38b, 38c) are provided in the discharge pipes (21a, 21b), respectively. Each high pressure switch (38a, 38b, 38c) is configured to detect the discharge pressure and to urgently stop the compression mechanism (40) when the pressure is abnormally high.

《Circuit circuit》
Each internal circuit (61) is provided with a drain pan heating pipe (62), an internal expansion valve (63), and an internal heat exchanger (64) in that order from the liquid side end to the gas side end. ing.

  The internal expansion valve (63) is an electronic expansion valve whose opening degree can be adjusted. The internal heat exchanger (64) is a cross-fin fin-and-tube heat exchanger. The internal heat exchanger (64) constitutes a use side heat exchanger. In the vicinity of the internal heat exchanger (64), an internal fan (65) for sending internal air to the internal heat exchanger (64) is provided. In the internal heat exchanger (64), heat is exchanged between the refrigerant and the internal air. Further, the drain pan heating pipe (62) is disposed in a drain pan (66) provided below the internal heat exchanger (64).

<Configuration of controller>
The refrigeration apparatus (1) of the present embodiment is provided with a controller (50) for controlling the operation of the refrigeration apparatus (1). The controller (50) constitutes a control means. The controller (50) controls the compression mechanism (40), the four-way switching valve (20), the first and second external expansion valves (18, 19), the solenoid valves (SV1 to SV7), etc. It is configured. In this embodiment, the controller (50) includes a capacity control unit (51) and an operation switching unit (52).

  The capacity controller (51) controls the operating capacity of the compression mechanism (40) of each external unit (10a, 10b, 10c) so that the required cooling capacity can be obtained in each internal unit (60a, 60b). It is configured as follows. The capacity control unit (51) causes the compression mechanism (40) of each external unit (10a, 10b, 10c) to operate only the first compressor (14a) first, and when the operating capacity is insufficient The second compressor (14b) and the third compressor (14c) are sequentially activated. The operating capacity of the first compressor (14a) is adjusted in stages according to the required operating capacity.

  In addition, the capacity control unit (51) has an external circuit (11) in which the end of the switching operation for switching the four-way switching valve (20) ends when the operation state is switched between the cooling operation and the defrost operation. Except for, the compression mechanism (40) of the external circuit (11) for which the switching operation has been completed is stopped. Further, the capacity control unit (51), when switching the operation state, all the compressors (40) of the compression mechanism (40) of the external circuit (11) in which the four-way switching valve (20) is executing the switching operation ( 14) is operated, the operating capacity of the compression mechanism (40) of the external circuit (11) in which the four-way switching valve (20) is performing switching operation, and the four-way switching valve (20) performs switching operation. It is configured to set a value larger than that of the outside circuit (11) that is not executed.

  The operation switching unit (52) is configured to control switching of the operation state between the cooling operation and the defrost operation. The operation switching unit (52) switches the operation state by sequentially switching the four-way switching valves (20) of the three external circuits (11) one by one.

  The operation switching unit (52) performs a determination operation for determining whether or not the switching operation of the four-way switching valve (20) is completed after instructing the switching operation to the four-way switching valve (20). Configured to do. In the determination operation, the operation switching unit (52) detects the detected value of the high pressure sensor (35) of the external circuit (11) provided with the four-way switching valve (20) that commanded the switching operation and the low pressure sensor (36). The difference from the detected value is calculated as a high / low pressure difference. Then, the operation switching unit (52) determines that the switching operation has ended when the high-low pressure difference exceeds a preset determination value (for example, 0.3 MPa).

-Operation of refrigeration equipment-
Below, the operation | movement operation | movement of the freezing apparatus (1) of this embodiment is demonstrated.

<Cooling operation>
In the cooling operation, the four-way selector valve (20) is set to the first state. The first outside expansion valve (18) is set to a fully closed state. Then, when the compression mechanism (40) is operated in this state, in the refrigerant circuit (4), the external heat exchanger (15) serves as a condenser and the internal heat exchanger (64) serves as an evaporator. A compression refrigeration cycle is performed. During the cooling operation, the opening degrees of the second external expansion valve (19) and the internal expansion valves (63) are adjusted as appropriate.

  Specifically, when the compression mechanism (40) is activated, the refrigerant discharged from the compression mechanism (40) passes through the oil separator (33) and the four-way switching valve (20), and then the external heat exchanger ( 15) In the external heat exchanger (15), the refrigerant exchanges heat with external air and condenses. The refrigerant condensed in the external heat exchanger (15) is temporarily stored in the receiver (23), and then passes through the high-pressure side flow path (17a) of the supercooling heat exchanger (17). Flows into the pipe (25). In the second liquid pipe (25), a part of the refrigerant flows into the first branch pipe (33). The remaining refrigerant flows into the liquid side connecting pipe (2).

  The refrigerant that has flowed into the first branch pipe (33) is depressurized by the second external expansion valve (19) and then flows through the low pressure side flow path (17b) of the supercooling heat exchanger (17). In the supercooling heat exchanger (17), the low-pressure refrigerant in the low-pressure channel (17b) exchanges heat with the high-pressure refrigerant in the high-pressure channel (17a) and evaporates. On the other hand, the refrigerant in the high-pressure channel (17a) dissipates heat to the low-pressure refrigerant in the low-pressure channel (17b) and enters a supercooled state. The gas refrigerant evaporated in the low-pressure channel (17b) flows into the compression mechanism (40) through the gas injection pipe (30).

  The refrigerant that has flowed into the liquid side communication pipe (2) is distributed to each internal circuit (61), decompressed by each internal expansion valve (63), and then flows into each internal heat exchanger (64). In each internal heat exchanger (64), the refrigerant evaporates by exchanging heat with the internal air. The internal air is cooled by the refrigerant. The refrigerant evaporated in each internal heat exchanger (64) joins in the gas side communication pipe (3), passes through the four-way switching valve (20), and is sucked into the compression mechanism (40).

<Defrost operation>
In the refrigeration apparatus (1), when the amount of frost on the internal heat exchanger (64) increases during the cooling operation, the defrost operation is performed to remove the frost. In the defrost operation, defrosting of the internal heat exchangers (64) is performed simultaneously.

  In the defrost operation, the four-way selector valve (20) is set to the second state. Each internal expansion valve (63) is set to a fully open state. When the compression mechanism (40) is operated in this state, in the refrigerant circuit (4), the external heat exchanger (15) serves as an evaporator and the internal heat exchanger (64) serves as a condenser. A compression refrigeration cycle is performed. During the defrost operation, the opening degree of the first external expansion valve (18) and the second external expansion valve (19) is adjusted as appropriate.

  Specifically, when the compression mechanism (40) is activated, the refrigerant discharged from the compression mechanism (40) passes through the oil separator (33) and the four-way switching valve (20), and each heat exchanger in the cabinet To (64). In each internal heat exchanger (64), the attached frost is melted by the high-pressure refrigerant, while the refrigerant is cooled and condensed by the frost. The refrigerant condensed in the internal heat exchanger (64) is temporarily stored in the receiver (23), and then passes through the high-pressure side flow path (17a) of the supercooling heat exchanger (17) to enter the second liquid. Flows into the pipe (25). The refrigerant flowing into the second branch pipe (28) is decompressed by the first external expansion valve (18) of the third branch pipe (29) and then flows into the external heat exchanger (15). In the external heat exchanger (15), the refrigerant exchanges heat with external air and evaporates. The refrigerant evaporated in the external heat exchanger (15) passes through the four-way switching valve (20) and is sucked into the compression mechanism (40).

<Operation of controller>
The operation of the controller (50) when switching the operation state between the cooling operation and the defrost operation will be described. Hereinafter, an operation when switching from the cooling operation to the defrost operation while the compression mechanisms (40) of all the external circuits (11) are operating will be described with reference to FIG.

  During the cooling operation, the operation switching unit (52) of the controller (50) is, for example, an external heat exchange estimated based on a measured value of a temperature sensor (not shown) that measures the temperature of the external heat exchanger (15). When the frosting amount of the vessel (15) reaches a predetermined value, it is determined to execute the defrost operation. When the operation switching unit (52) determines the execution of the defrost operation, the four-way switching valves (20) of all the external circuits (11) in which the compression mechanism (40) is operating are sequentially in the first state. To the second state.

  Specifically, in step 1 (ST1), the operation switching unit (52) first instructs the four-way switching valve (20) of the first outside unit (10a) to switch to the second state. Outputs a command. When the four-way selector valve (20) of the first outside unit (10a) receives the switching command, the pilot valve (54) adjusts so that the left cylinder chamber (48) communicates with the third port (P3). Is done. When the pilot valve (54) is adjusted, the right cylinder chamber (49) becomes a high pressure space and the left cylinder chamber (48) becomes a low pressure space. As a result, the four-way switching valve (20) of the first outside unit (10a) starts the switching operation for switching from the first state to the second state, and the valve body (55) gradually moves to the left side. go.

  Further, the capacity control unit (51) outputs the switching command to the four-way switching valve (20) of the first outside unit (10a) at the same time as the operation switching unit (52), and at the same time, each outside unit (60a, 60b, A capacity adjustment command for instructing the adjustment of the operating capacity is output to the compression mechanism (40) of 60c). In the capacity control unit (51), the first compressor (14a) of all the external units (10a, 10b, 10c) has a capacity in the high speed region (for example, the fifteenth capacity from the bottom in 20 stages) The second compressor (14b) of all the external units (10a, 10b, 10c) is turned on, and the third compressor (14c) of the first external unit (10a) is turned on. Output capacity adjustment command. As a result, in each external unit (60a, 60b, 60c), the operating state of each compressor (14) of the compression mechanism (40) is adjusted based on the capacity adjustment command. In the second external unit (10b) and the third external unit (10c), if the third compressor (14c) is in operation, the operation of the third compressor (14c) is stopped.

  In this embodiment, the operating capacity of the compression mechanism (40) of the first outside unit (10a) in which the switching operation is performed is the same as the operating capacity of the compression mechanism (40) of the other outside units (10b, 10c). Is set to a larger value. In the first outside unit (10a) in which the switching operation is performed, the operation capacity of the compression mechanism (40) is set to a relatively high value. For this reason, since the refrigerant | coolant flow volume in a four-way selector valve (20) becomes comparatively large, it becomes possible to move a valve body (55) rapidly.

  Subsequently, in step 2 (ST2), the operation switching unit (52) performs a determination operation for determining whether or not the switching operation of the four-way switching valve (20) of the first external unit (10a) has been completed. Do. In the determination operation, the operation switching unit (52) determines that the difference between the measured value of the high pressure sensor (35) of the first outside unit (10a) and the measured value of the low pressure sensor (36) is a predetermined value (eg, 0.3 MPa). If the above condition is satisfied, it is determined that the switching operation has been completed. If it is determined that the switching operation has been completed, the process proceeds to step 3 (ST3). On the other hand, if the above condition is not satisfied, it is determined that the switching operation has not been completed, and step 2 (ST2) is performed again after a predetermined time (for example, 10 seconds) has elapsed. Step 2 (ST2) is repeated until the above condition is satisfied.

  Subsequently, in Step 3 (ST3), the capacity controller (51) stops all the compressors (14a, 14b, 14c) with respect to the compression mechanism (40) of the first outside unit (10a). The stop command to be commanded is output. In the compression mechanism (40) of the first outside unit (10a), when a stop command is received, all the compressors (14a, 14b, 14c) are stopped.

  Subsequently, in step 4 (ST4), the operation switching unit (52) issues a switching command for instructing the four-way switching valve (20) of the second external unit (10b) to switch to the second state. Output. When the four-way switching valve (20) of the second external unit (10b) receives the switching command, the pilot valve (54) adjusts so that the left cylinder chamber (48) communicates with the third port (P3). Then, a switching operation for switching from the first state to the second state is started.

  The capacity control unit (51) outputs the switching command to the four-way switching valve (20) of the second external unit (10b) at the same time as the operation switching unit (52), and simultaneously the second external unit (10b) and A capacity adjustment command for instructing adjustment of the operating capacity is output to the compression mechanism (40) of the third external unit (10c). The capacity control unit (51) is configured such that the first compressor (14a) of the second external unit (10b) and the third external unit (10c) has the capacity in the high speed region, and the second external unit (10b) And the second compressor (14b) of the third external unit (10c) is turned on, and the capacity adjustment command is set so that the third compressor (14c) of the second external unit (10b) is turned on. Is output. As a result, the third compressor (14c) is activated in the second external unit (10b).

  Subsequently, in step 5 (ST5), the operation switching unit (52) performs a determination operation for determining whether or not the switching operation of the four-way switching valve (20) of the second external unit (10b) has been completed. Do. In the determination operation, the operation switching unit (52) determines that the difference between the measured value of the high pressure sensor (35) of the second external unit (10b) and the measured value of the low pressure sensor (36) is a predetermined value (eg, 0.3 MPa). If the above condition is satisfied, it is determined that the switching operation has been completed. If it is determined that the switching operation has been completed, the process proceeds to step 6 (ST6). On the other hand, if the above condition is not satisfied, it is determined that the switching operation has not been completed, and step 5 (ST5) is performed again after a predetermined time (for example, 10 seconds) has elapsed. Step 5 (ST5) is repeated until the above condition is satisfied.

  Subsequently, in Step 6 (ST6), the capacity controller (51) stops all the compressors (14a, 14b, 14c) with respect to the compression mechanism (40) of the second external unit (10b). The stop command to be commanded is output. In the compression mechanism (40) of the second external unit (10b), when a stop command is received, all the compressors (14a, 14b, 14c) are stopped.

  Subsequently, in step 7 (ST7), the operation switching unit (52) issues a switching command for commanding switching to the second state to the four-way switching valve (20) of the third external unit (10c). Output. When the four-way switching valve (20) of the third external unit (10c) receives the switching command, the pilot valve (54) adjusts so that the left cylinder chamber (48) communicates with the third port (P3). Then, a switching operation for switching from the first state to the second state is started.

  The capacity control unit (51) outputs the switching command to the four-way switching valve (20) of the third external unit (10c) at the same time that the operation switching unit (52) outputs the switching command of the third external unit (10c). A capacity adjustment command for commanding adjustment of the operating capacity is output to the compression mechanism (40). The capacity control unit (51) is configured so that the first compressor (14a) has the capacity in the high speed region, the second compressor (14b) is turned on, and the third compressor (14c) is turned on. Output a capacity adjustment command. As a result, the third compressor (14c) is activated in the third external unit (10c).

  Subsequently, in step 8 (ST8), the operation switching unit (52) performs a determination operation for determining whether or not the switching operation of the four-way switching valve (20) of the third external unit (10c) has been completed. Do. In the determination operation, the operation switching unit (52) determines that the difference between the measured value of the high pressure sensor (35) of the third external unit (10c) and the measured value of the low pressure sensor (36) is a predetermined value (eg, 0.3 MPa). If the above condition is satisfied, it is determined that the switching operation has been completed. If it is determined that the switching operation has been completed, the process proceeds to step 9 (ST9). On the other hand, if the above condition is not satisfied, it is determined that the switching operation has not yet been completed, and step 8 (ST8) is performed again after a predetermined time (for example, 10 seconds) has elapsed. Step 8 (ST8) is repeated until the above condition is satisfied.

  Subsequently, in Step 9 (ST9), the capacity controller (51) performs the second compressor (14b) and the third compressor (14c) with respect to the compression mechanism (40) of the third external unit (10c). ) Stop command is output to stop. In the compression mechanism (40) of the third external unit (10c), when the stop command is received, the second compressor (14b) and the third compressor (14c) are stopped. The operation of the first compressor (14a) is continued. The capacity control unit (51) continues the operation of the compression mechanism (40) even after the switching operation is finished for the third external unit (10c) whose switching operation is finished last.

  The defrost operation is started when the switching operation of the four-way switching valves (20) of all the external units (10a, 10b, 10c) is completed. In step 10 (ST10), with the start of the defrost operation, the capacity control unit (51) controls the first compressor (14a) with respect to the first outside unit (10a) and the second outside unit (10b). ) Is output with a capacity adjustment command instructing to operate at a capacity in the high speed region. In each compression mechanism (40) of the first external unit (10a) and the second external unit (10b), upon receiving a capacity adjustment command, the first compressor (14a) is activated and the first compressor ( The operating capacity of 14a) is adjusted to the capacity in the high speed range.

  Thereafter, the operation switching unit (52), for example, determines the end of the defrost operation after a lapse of a predetermined time from the start of the defrost operation, and switches the operation state to the cooling operation. The operation switching unit (52) performs the switching operation of the three external units (10a, 10b, 10c) in the same order as when switching to the defrost operation when switching to the cooling operation. The operation switching unit (52) also performs switching operations of the three external units (10) one by one in order when switching to the cooling operation.

  The operation switching unit (52) changes the order of the external circuit (11) that performs the switching operation every time the defrost operation is performed. In the next defrosting operation, the order of the external unit (10) that first performs the switching operation in the previous defrosting operation is last, and the order of the second and subsequent external units (10) is incremented one by one.

-Effect of the embodiment-
In this embodiment, when switching the operation state, when the switching operation is completed in a certain external circuit (11), if there is an external circuit (11) for which the switching operation has not yet been completed, the controller ( 50) stops the compression mechanism (40) of the external circuit (11) for which the switching operation has been completed, and thus is discharged from the compression mechanism (40) of the external circuit (11) for which the switching operation has not been completed. It is avoided that the refrigerant flow is obstructed by the compression mechanism (40) of the external circuit (11) after the switching operation is completed. For this reason, in the external circuit (11) where the switching operation has not been completed, a high-low pressure difference necessary for moving the valve body (55) of the four-way switching valve (20) is secured, and the four-way switching valve (20) Can be smoothly switched. Accordingly, when the four-way switching valve (20) performs the switching operation in each of the plurality of external circuits (11) that are operating the compression mechanism (40), the four-way switching valve is switched. The switching operation of (20) can be performed smoothly.

  In the present embodiment, the switching operation of each external circuit (11) is performed without overlapping the time during the switching operation. Here, when the time of the switching operation of each external circuit (11) overlaps with each other, that is, when there are a plurality of external circuits (11) in which the switching operation is being performed, the external circuit (11 ) Exists, the compression mechanism (40) of the external circuit (11) for which the switching operation has been completed may be stopped. In such a case, the high / low pressure difference fluctuates temporarily due to the stop of the compression mechanism (40), so that the valve body (55) of the four-way switching valve (20) during the switching operation is affected by the fluctuation of the high / low pressure difference. End up. On the other hand, in this embodiment, since the time of the switching operation of each outside circuit (11) does not overlap each other, the fluctuation of the high-low pressure difference as described above occurs during the switching operation of each outside circuit (11). Does not occur. Therefore, the switching operation of each four-way switching valve (20) can be performed more smoothly.

  In addition, when there are multiple outside circuit (11) during the switching operation, the high pressure side and the low pressure side communicate with each other in the four-way switching valve (20) during the switching operation. Compared with the case where there is only one circuit (11), the high-low pressure difference tends to decrease as a whole in the refrigerant circuit (4). For this reason, the moving speed of the valve body (55) of the four-way switching valve (20) during the switching operation may decrease, and the valve body (55) may not move. On the other hand, in this embodiment, since there is one outside circuit (11) during the switching operation, the high / low pressure difference does not decrease so much. Therefore, the switching operation of each external circuit (11) can be completed reliably.

  In addition, when there are a plurality of external circuits (11) in which the switching operation is being performed, when the switching operation is completed in a certain external circuit (11), within the four-way switching valve (20) where the switching operation has been completed. Since the state where the high-pressure side and the low-pressure side communicate with each other is eliminated, the high-low pressure difference temporarily rises. For this reason, when the end of the switching operation is determined based on the high / low pressure difference as in the present embodiment, there is a risk of erroneously determining that the switching operation has ended in the other external circuit (11). On the other hand, in this embodiment, since one switching operation is performed for each of the three external circuits (11), the end of the switching operation of each external circuit (11) can be accurately determined. There is no misjudgment of the end of operation. Therefore, the operation state can be accurately switched.

  Moreover, in this embodiment, more refrigerant | coolants than the external circuit (11) in which the four-way selector valve (20) has not performed switching operation yet, and the four-way selector valve (20) are performing switching operation. It distributes to the external circuit (11). For this reason, a relatively large amount of refrigerant flows through the four-way switching valve (20) that is performing the switching operation. By the way, as for the four-way selector valve (20), the moving speed of the valve element (55) increases as the refrigerant flow rate increases. Accordingly, in the four-way switching valve (20) that is executing the switching operation, the valve element (55) moves quickly, so that the switching operation can be completed in a relatively short time.

  Moreover, in this embodiment, when switching to a defrost operation and returning to a cooling operation, it stops from the compression mechanism (40) of the same external circuit (11). Therefore, when switching to the defrost operation and returning to the cooling operation, the order of the length of the operation time of the compression mechanism (40) becomes the same, and the refrigerator oil is more in the outside circuit (11) where the switching operation is performed later. Easy to collect. For this reason, it is possible to grasp to some extent that the compressor mechanism (40) of which external circuit (11) is likely to accumulate refrigeration oil from the start of switching to defrost operation to the return to cooling operation. Management of the amount of refrigeration oil in the compression mechanism (40) of the circuit (11) can be facilitated.

  Further, in this embodiment, the compression mechanism (40) that increases the operation time from the cooling operation to the cooling operation through the defrosting operation is changed every time the defrosting operation is performed. Therefore, every time the defrost operation is performed, the compression mechanism (40) in which the refrigerating machine oil easily accumulates is changed. Therefore, it is possible to avoid the concentration of refrigerating machine oil in one compression mechanism (40), and the amount of refrigerating machine oil in each compression mechanism (40) can be made uniform.

<< Other Embodiments >>
About the said embodiment, it is good also as following structures.

  In the above embodiment, the refrigeration apparatus (1) may be configured to perform a supercritical cycle in which the high pressure of the refrigeration cycle is set to a value higher than the critical pressure of the refrigerant. In that case, one of the external heat exchanger (15) and the internal heat exchanger (64) operates as a gas cooler, and the other operates as an evaporator.

  In the above embodiment, the refrigeration apparatus (1) may be an air conditioner that can selectively execute a cooling operation and a heating operation.

  Moreover, about the said embodiment, the 4th gas piping connected to the discharge side of a compression mechanism (40) may be connected to the pilot valve (54). The pilot valve (54) includes a state in which the first gas pipe (41) and the second gas pipe (42) communicate with each other, the third gas pipe (43) and the fourth gas pipe communicate with each other, and the first gas pipe. (41) and the fourth gas pipe communicate with each other and the second gas pipe (42) and the third gas pipe (43) communicate with each other.

  In addition, the above embodiment is an essentially preferable illustration, Comprising: It does not intend restrict | limiting the range of this invention, its application thing, or its use.

  As described above, the present invention is useful for a refrigeration apparatus in which a four-way switching valve is connected to a compression mechanism composed of a plurality of compressors.

FIG. 1 is a schematic configuration diagram of a refrigeration apparatus according to an embodiment of the present invention. FIG. 2 is a refrigerant circuit diagram of an external circuit of the refrigeration apparatus according to the embodiment of the present invention. FIG. 3 is a refrigerant circuit diagram of the internal circuit of the refrigeration apparatus according to the embodiment of the present invention. FIG. 4 is a cross-sectional view of the four-way switching valve in the embodiment. FIG. 5 is a flowchart showing the operation of the controller of the refrigeration apparatus in the embodiment.

Explanation of symbols

1 Refrigeration equipment 2 Liquid side connection piping (liquid line)
3 Gas side communication piping (gas line)
4 Refrigerant circuit 10 External unit 40 Compression mechanism 50 Controller (control means)
51 Capacity control unit 52 Operation switching unit 60 Internal unit

Claims (7)

A plurality of heat source side circuits (11) each provided with a compression mechanism (40) comprising one or a plurality of compressors (14), a four-way switching valve (20) and a heat source side heat exchanger (15);
A utilization side circuit (61) provided with a utilization side heat exchanger (64);
A gas line (3) constituting the refrigerant circuit (4) by connecting the plurality of heat source side circuits (11) and the use side circuit (61) so that the plurality of heat source side circuits (11) are parallel to each other. And a liquid line (2),
The four-way switching valve (20) of each of the heat source side circuits (11) includes a valve body (55) driven by a pressure difference between the refrigerant discharged from the compression mechanism (40) and the suction refrigerant, and the compression mechanism ( A first state in which the discharge side of 40) communicates with the liquid line (2) and the suction side of the compression mechanism (40) communicates with the gas line (3), and the discharge of the compression mechanism (40). Switching operation from the second state in which the suction side of the compression mechanism (40) and the liquid line (2) communicate with each other and the gas line (3) is switched from one to the other, A refrigeration apparatus configured to be performed by moving the valve body (55),
When the operation state is switched by causing the four-way switching valve (20) to perform the switching operation in each of the plurality of heat source side circuits (11) in which the compression mechanism (40) is operating, the switching operation is completed. When the switching operation is finished in the heat source side circuit (11) other than the heat source side circuit (11), the control means (50) for stopping the compression mechanism (40) of the heat source side circuit (11) that has finished the switching operation. A refrigeration apparatus comprising: In claim 1,
When the control means (50) switches the operation state by the switching operation in the plurality of heat source side circuits (11), the compression mechanism (40) is operated in the plurality of heat source side circuits (11) in operation. The refrigeration apparatus is characterized by causing the four-way switching valve (20) to perform a switching operation so that the switching operations are sequentially performed one by one. In claim 2,
When the control means (50) switches the operation state by the switching operation in the plurality of heat source side circuits (11), the four-way switching valve (20) is performing the switching operation ( The operating capacity of the compression mechanism (40) of 11) is set to a larger value than the heat source side circuit (11) where the four-way switching valve (20) has not yet performed the switching operation. . In any one of Claims 1 thru | or 3,
In each of the heat source side circuits (11), the compression mechanism (40) is composed of a plurality of compressors (14),
The control means (50), when switching the operation state by the switching operation in the plurality of heat source side circuits (11), is a compression mechanism (40) of the heat source side circuit (11) that is executing the switching operation. A refrigeration system characterized by operating all the compressors (14). In any one of Claims 1 thru | or 4,
When the control means (50) performs switching of the operation state by the switching operation in the plurality of heat source side circuits (11), for the heat source side circuit (11) in which the end of the switching operation is the last, The refrigeration apparatus characterized in that the operation of the compression mechanism (40) is continued even after the end of the switching operation. In claim 2 or 3,
A cooling operation in which the four-way switching valve (20) is set to the first state and the use side heat exchanger (64) operates as an evaporator;
While the four-way selector valve (20) is set to the second state and performs the defrost operation for melting ice adhering to the use side heat exchanger (64) during the cooling operation,
The control means (50) includes a heat source side circuit (11) that performs the switching operation when switching from the cooling operation to the defrosting operation and when returning from the defrosting operation to the cooling operation when performing the defrosting operation. The refrigeration apparatus characterized by making the order of the same. In claim 6,
The said control means (50) changes the order of the heat-source side circuit (11) which performs the said switching operation for every time of the said defrost driving | operation, The freezing apparatus characterized by the above-mentioned.

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