WO2014050099A1

WO2014050099A1 - Refrigerating device

Info

Publication number: WO2014050099A1
Application number: PCT/JP2013/005688
Authority: WO
Inventors: 竹上　雅章; 東近藤; 覚阪江; 植野　武夫
Original assignee: ダイキン工業株式会社
Priority date: 2012-09-28
Filing date: 2013-09-25
Publication date: 2014-04-03
Also published as: JP5682606B2; JP2014070822A

Abstract

A first compressor (111) and a second compressor (112) are provided in a refrigeration circuit (11) of a refrigerating device (10). The first compressor (111) links to a first use-side heat exchanger (74) via a first intake piping (32). The second compressor (112) links to a second use-side heat exchanger (84) or a heat source side heat exchanger (26) via a second intake pipe (34). The first intake pipe (32) and the second intake pipe (34) are joined via a joining pipe (47). A control valve (48) with a variable opening is provided in the joining pipe (47). The cooling capacity of the refrigerating device (10) is easily controlled by adjusting the opening of the control valve (48).

Description

Refrigeration equipment

The present invention relates to a refrigeration apparatus provided with a plurality of types of use side heat exchangers.

Conventionally, a refrigeration apparatus having a plurality of types of use-side heat exchangers is known. For example, Patent Document 1 discloses an indoor heat exchanger that is a usage-side heat exchanger for performing indoor cooling or heating, and a refrigeration heat that is a usage-side heat exchanger for cooling the interior of a showcase or the like. A refrigeration apparatus including an exchanger is disclosed. In the refrigerant circuit of the refrigeration apparatus, three compressors are provided. In this refrigerant circuit, the first compressor sucks and compresses the refrigerant evaporated in the refrigeration heat exchanger, and the third compressor sucks and compresses the refrigerant evaporated in the indoor heat exchanger. Further, the second compressor switches between a state in which the refrigerant evaporated in the refrigeration heat exchanger is sucked and a state in which the refrigerant evaporated in the indoor heat exchanger is sucked.

In the refrigeration apparatus of Patent Document 1, when the cooling load in the refrigeration heat exchanger cannot be processed only by the first compressor, the second compressor is in a state of sucking in the refrigerant evaporated in the refrigeration heat exchanger. In this case, a part of the refrigerant evaporated in the refrigeration heat exchanger is sucked into the first compressor, and the rest is sucked into the second compressor. On the other hand, in this refrigeration apparatus, when the cooling load in the air conditioning heat exchanger cannot be processed only by the third compressor, the second compressor sucks the refrigerant evaporated in the indoor heat exchanger. In this case, a part of the refrigerant evaporated in the air conditioning heat exchanger is sucked into the third compressor, and the rest is sucked into the second compressor.

JP 2009-180451 A

In the refrigeration apparatus of Patent Document 1, the number of compressors that draw refrigerant from the refrigeration heat exchanger or the air conditioning heat exchanger is changed from one to two, or from two by switching the connection destination of the second compressor. Change to one. For this reason, the cooling capacity obtained in the refrigeration heat exchanger and the cooling capacity obtained in the air-conditioning heat exchanger may change abruptly, making it difficult to appropriately control the capacity of the refrigeration apparatus.

The present invention has been made in view of such a point, and an object thereof is to improve the usability of the refrigeration apparatus by appropriately controlling the capacity of the refrigeration apparatus.

The first invention includes a first compressor section (111) and a second compressor section (112) each constituted by one or a plurality of compressors (24, 25), a heat source side heat exchanger ( 26), a refrigeration apparatus having a refrigerant circuit (11) having a first usage side heat exchanger (74) and a second usage side heat exchanger (84) for performing a refrigeration cycle. The refrigerant circuit (11) is connected to the first compressor part (111) and communicates the first compressor part (111) with the first use side heat exchanger (74). The pipe (32), the second suction pipe (34) connected to the second compressor section (112), and the second suction pipe (34) communicate with the second use side heat exchanger (84). A switching mechanism (110) for switching between the state and the state where the second suction pipe (34) communicates with the heat source side heat exchanger (26), and one end connected to the first suction pipe (32). The other end is provided with a connection pipe (47) connected to the second suction pipe (34), and a variable opening control valve (48) provided in the connection pipe (47).

In the first invention, the refrigerant circuit (11) is provided in the refrigeration apparatus (10). In the refrigerant circuit (11), the compressor (24) constituting the first compressor section (111) is connected to the first usage-side heat exchanger (74) via the first suction pipe (32). When the first usage-side heat exchanger (74) functions as an evaporator, the refrigerant evaporated in the first usage-side heat exchanger (74) passes through the first suction pipe (32) and becomes the first compressor section. It is sucked into the compressor (24) constituting (111). In the refrigerant circuit (11), the compressor (25) constituting the second compressor section (112) is connected to the second suction pipe (34), and the second suction pipe (34) is connected to the switching mechanism (110). To the second usage side heat exchanger (84) and the heat source side heat exchanger (26). When the second usage-side heat exchanger (84) functions as an evaporator, the switching mechanism (110) is in a state where the second suction pipe (34) communicates with the second usage-side heat exchanger (84), The refrigerant evaporated in the 2-use side heat exchanger (84) is sucked into the compressor (25) constituting the second compressor section (112) through the second suction pipe (34). On the other hand, when the heat source side heat exchanger (26) functions as an evaporator, the switching mechanism (110) enters a state where the second suction pipe (34) communicates with the heat source side heat exchanger (26), and the heat source side heat exchanger The refrigerant evaporated in the exchanger (26) is sucked into the compressor (25) constituting the second compressor part (112) through the second suction pipe (34).

In the first invention, the connection pipe (47) is provided in the refrigerant circuit (11). The connection pipe (47) is provided with a control valve (48). In a state where the control valve (48) is opened, a part of the refrigerant flowing through the first suction pipe (32) is sucked into the second compressor section (112) or one of the refrigerant flowing through the second suction pipe (34). Part is sucked into the first compressor part (111). In the former case, a part of the refrigerant flowing into the first suction pipe (32) from the first use side heat exchanger (74) passes through the connection pipe (47) to the second compressor section (112). The air is sucked and the rest is sucked into the first compressor section (111). In this case, as the opening of the control valve (48) increases, the flow rate of the refrigerant sucked into the second compressor section (112) through the connection pipe (47) increases. On the other hand, in the latter case, a part of the refrigerant flowing into the second suction pipe (34) from the second use side heat exchanger (84) or the heat source side heat exchanger (26) passes through the connection pipe (47). The air is sucked into the first compressor part (111) and the rest is sucked into the second compressor part (112). In this case, the flow rate of the refrigerant sucked into the first compressor part (111) through the connection pipe (47) increases as the opening degree of the control valve (48) increases.

According to a second aspect of the present invention, in the first aspect, the heat source side heat exchanger (26) functions as a condenser, and the first usage side heat exchanger (74) and the second usage side heat exchanger ( 84) can perform the first cooling operation in which both function as an evaporator, the operating capacity of the first compressor unit (111) and the second compressor unit (112), and the control valve (48). A controller (120) for adjusting the opening of the first compressor unit (111) and the second compressor unit (112) during the first cooling operation. When the operating capacity is lower than a predetermined reference capacity, the first compressor is configured such that the control valve (48) is kept in a fully closed state and the refrigerant pressure in the first suction pipe (32) becomes the first target low pressure. The operating capacity of the section (111) is adjusted so that the refrigerant pressure in the second suction pipe (34) becomes a second target low pressure higher than the first target low pressure. It is intended to adjust the operating capacity of the second compressor unit (112).

The refrigeration apparatus (10) of the second invention can execute the first cooling operation. During the first cooling operation, the refrigerant evaporated in the first usage-side heat exchanger (74) is drawn into the first compressor section (111) through the first suction pipe (32), and the second usage-side heat is supplied. The refrigerant evaporated in the exchanger (84) is sucked into the second compressor section (112) through the second suction pipe (34). The refrigerating apparatus (10) of the present invention is provided with a controller (120).

When the operation capacities of the first compressor unit (111) and the second compressor unit (112) are below a predetermined reference capacity during the first cooling operation, the cooling load in the first use side heat exchanger (74) is reduced. Only the first compressor section (111) can process the cooling load in the second usage side heat exchanger (84), and only the second compressor section (112) can process the cooling load. Therefore, the controller (120) of the second invention keeps the control valve (48) in a fully closed state. In this case, the refrigerant evaporated in the first usage-side heat exchanger (74) is sucked only into the compressor (24) constituting the first compressor section (111), and the second usage-side heat exchanger (84). The refrigerant evaporated in is sucked only into the compressor (25) constituting the second compressor section (112).

In this case, the controller (120) of the second invention adjusts the operating capacity of the first compressor section (111) so that the refrigerant pressure in the first suction pipe (32) becomes the first target low pressure. The operating capacity of the second compressor section (112) is adjusted so that the refrigerant pressure in the second suction pipe (34) becomes the second target low pressure. The second target low pressure is higher than the first target low pressure. For this reason, the evaporation temperature of the refrigerant in the second usage-side heat exchanger (84) is higher than the evaporation temperature of the refrigerant in the first usage-side heat exchanger (74).

In a third aspect based on the second aspect, the controller (120) is configured such that the operating capacity of the first compressor unit (111) falls below the reference capacity during the first cooling operation, and the second controller When the operating capacity of the compressor section (112) is greater than or equal to the reference capacity, the opening of the control valve (48) is adjusted so that the refrigerant pressure in the first suction pipe (32) becomes the first target low pressure. Adjusting and adjusting the operating capacity of the first compressor section (111) so that the refrigerant pressure in the second suction pipe (34) becomes the second target low pressure, or the second suction pipe (34) The opening of the control valve (48) is adjusted so that the refrigerant pressure becomes the second target low pressure, and the first suction pressure (32) becomes the first target low pressure. The operation of adjusting the operating capacity of the compressor section (111) is performed.

In the controller (120) of the third invention, during the first cooling operation, the operating capacity of the first compressor section (111) is less than the reference capacity, and the operating capacity of the second compressor section (112) is greater than the reference capacity. If it is, a predetermined operation is performed. In this case, the cooling load in the second usage-side heat exchanger (84) cannot be processed only by the second compressor section (112), or the cooling load in the second usage-side heat exchanger (84) is reduced. It is not appropriate to process only the second compressor section (112). Therefore, the controller (120) performs one of the following first operation and second operation.

The first operation performed by the controller (120) of the third invention is to adjust the opening of the control valve (48) so that the refrigerant pressure in the first suction pipe (32) becomes the first target low pressure, This is an operation for adjusting the operating capacity of the first compressor section (111) so that the refrigerant pressure of the two suction pipes (34) becomes the second target low pressure. Further, the second operation performed by the controller (120) is to adjust the opening of the control valve (48) so that the refrigerant pressure in the second suction pipe (34) becomes the second target low pressure, and to perform the first suction. In this operation, the operating capacity of the first compressor unit (111) is adjusted so that the refrigerant pressure in the pipe (32) becomes the first target low pressure.

When the controller (120) of the third invention performs the first or second operation, a part of the refrigerant flowing through the second suction pipe (34) passes through the connection pipe (47) to form the first compressor section. Inhaled to (111). That is, the first compressor section (111) whose operating capacity is lower than the reference capacity removes all of the refrigerant flowing through the first suction pipe (32) and part of the refrigerant flowing through the second suction pipe (34). Inhale. Therefore, the cooling load in the first usage-side heat exchanger (74) is processed only by the first compressor unit (111), while the cooling load in the second usage-side heat exchanger (84) is the first Processed by both the compressor section (111) and the second compressor section (112).

In a fourth aspect based on the second aspect or the third aspect, the controller (120) includes the first compressor section (111) and the second compressor section (112) during the first cooling operation. When the operating capacity is equal to or greater than a predetermined reference capacity, the opening of the control valve (48) is adjusted so that the refrigerant pressure in the first suction pipe (32) becomes the first target low pressure. .

When the controller (120) of the fourth invention performs this operation, normally, the opening of the control valve (48) gradually decreases. As a result, the connection pipe (34) is connected from the second suction pipe (34). 47) The flow rate of the refrigerant drawn into the first compressor section (111) through 47) decreases. For this reason, the flow rate of the refrigerant that can be sucked from the first suction pipe (32) by the first compressor section (111) increases, and the rise in the refrigerant pressure of the first suction pipe (32) is suppressed.

According to a fifth invention, in any one of the second to fourth inventions, the heat source side heat exchanger (26) functions as a condenser, and the second usage side heat exchanger (84) is an evaporator. And the second cooling operation in which the first usage-side heat exchanger (74) is suspended can be executed, and the controller (120) can perform the second compressor section ( 112) is less than the reference capacity, the control valve (48) is kept in a fully closed state, the first compressor part (111) is kept in a stopped state, and the second suction pipe (34) The operating capacity of the second compressor section (112) is adjusted so that the refrigerant pressure becomes the second target low pressure.

The refrigeration apparatus (10) of the fifth invention can execute the second cooling operation. During the second cooling operation, the refrigerant evaporated in the second usage side heat exchanger (84) is sucked into the second compressor section (112) through the second suction pipe (34). When the operation capacity of the second compressor section (112) is lower than the reference capacity during the second cooling operation, the cooling load in the second usage side heat exchanger (84) is limited to the second compressor section (112). Can be processed. Therefore, the controller (120) keeps the control valve (48) fully closed, and operates the second compressor section (112) so that the refrigerant pressure in the second suction pipe (34) becomes the second target low pressure. Adjust the volume. In this case, the refrigerant evaporated in the second usage side heat exchanger (84) is sucked only into the compressor (25) constituting the second compressor section (112).

In a sixth aspect based on the fifth aspect, the controller (120) is configured such that the operating capacity of the second compressor section (112) is equal to or greater than the reference capacity during the second cooling operation. The opening degree of the control valve (48) is adjusted so that the refrigerant pressure in the first suction pipe (32) becomes the first target low pressure, and the refrigerant pressure in the second suction pipe (34) becomes the second target low pressure. The operating capacities of the first compressor section (111) and the second compressor section (112) are adjusted so that

The controller (120) according to the sixth aspect of the present invention is configured such that when the operation capacity of the second compressor section (112) is equal to or greater than a reference capacity during the second cooling operation, the opening degree of the control valve (48) and the first compression The operation capacity of the machine part (111) and the second compressor part (112) is adjusted. In this case, a part of the refrigerant evaporated in the second use side heat exchanger (84) is sucked into the first compressor part (111) through the connection pipe (47), and the rest is the second compressor. Inhaled into the part (112). That is, the cooling load in the second usage side heat exchanger (84) is processed by both the first compressor unit (111) and the second compressor unit (112). Then, the refrigerant pressure in the first suction pipe (32) is kept at the first target low pressure, and the refrigerant pressure in the second suction pipe (34) is kept at the second target low pressure.

In a seventh aspect based on the sixth aspect, the controller (120) is configured such that the controller (120) has operating capacities of the first compressor section (111) and the second compressor section (112) during the second cooling operation. Is equal to or greater than the reference capacity, the opening of the control valve (48) is adjusted such that the refrigerant pressure in the first suction pipe (32) becomes the first target low pressure.

When the controller (120) of the seventh invention performs this operation, when the refrigerant passes through the control valve (48), the pressure decreases from the second target low pressure to the first target low pressure. 48) Opening is adjusted. For this reason, the refrigerant pressure in the first suction pipe (32) is kept at the first target low pressure even when the operation capacity of the first compressor section (111) is equal to or higher than the reference capacity during the second cooling operation.

According to an eighth invention, in any one of the second to seventh inventions, the heat source side heat exchanger (26) functions as a condenser, and the first usage side heat exchanger (74) is an evaporator. The third cooling operation in which the second usage-side heat exchanger (84) is stopped can be executed, and the controller (120) can perform the first compressor section ( When the operating capacity of 111) is lower than the reference capacity, the control valve (48) is fully closed and the first suction pipe (32) has the first target low pressure so that the refrigerant pressure becomes the first target low pressure. The operating capacity of the compressor section (111) is adjusted to keep the second compressor section (112) in a stopped state.

The refrigeration apparatus (10) of the eighth invention can perform the third cooling operation. During the third cooling operation, the refrigerant evaporated in the first usage-side heat exchanger (74) is drawn into the first compressor section (111) through the first suction pipe (32). If the operating capacity of the first compressor section (111) is lower than the reference capacity during the third cooling operation, the cooling load in the first usage side heat exchanger (74) is processed only by the first compressor section (111). can do. Therefore, the controller (120) keeps the control valve (48) in a fully closed state, and operates the first compressor unit (111) so that the refrigerant pressure in the first suction pipe (32) becomes the first target low pressure. Adjust the capacity. In this case, the refrigerant evaporated in the first usage-side heat exchanger (74) is sucked only into the compressor (24) constituting the first compressor section (111).

In a ninth aspect based on the eighth aspect, the controller (120) is configured such that the operating capacity of the first compressor unit (111) is equal to or greater than the reference capacity during the third cooling operation. The control valve (48) is fully opened, and the first compressor part (111) and the second compressor part (112) are set so that the refrigerant pressure in the first suction pipe (32) becomes the first target low pressure. ) Is adjusted.

The controller (120) of the ninth invention keeps the control valve (48) fully open when the operating capacity of the first compressor section (111) is equal to or greater than the reference capacity during the third cooling operation. The operating capacities of the first compressor unit (111) and the second compressor unit (112) are adjusted. In this case, a part of the refrigerant evaporated in the first use side heat exchanger (74) is sucked into the second compressor section (112) through the connection pipe (47), and the rest is the first compressor. Part (111) is inhaled. That is, the cooling load in the first usage side heat exchanger (74) is processed by both the first compressor unit (111) and the second compressor unit (112). Then, the refrigerant pressure in the first suction pipe (32) is maintained at the first target low pressure.

In a tenth aspect based on the first aspect, the heat source side heat exchanger (26) and the second usage side heat exchanger (84) function as a condenser, and the first usage side heat exchanger ( 74) can execute the first coexistence operation functioning as an evaporator, and the operation capacity of the first compressor unit (111) and the second compressor unit (112) and the opening of the control valve (48). A controller (120) for adjusting the degree, and when the operating capacity of the first compressor unit (111) falls below a predetermined reference capacity during the first concurrent operation, The operating capacity of the first compressor section (111) is adjusted so that the refrigerant pressure in the first suction pipe (32) becomes a predetermined target low pressure, and the second compressor section (112) is kept in a stopped state. Is.

The refrigeration apparatus (10) of the tenth invention can execute the first coexistence operation. During the first concurrent operation, a part of the refrigerant discharged from the first compressor section (111) is supplied to the heat source side heat exchanger (26), and the rest is supplied to the second usage side heat exchanger (84). The refrigerant supplied and evaporated in the first use side heat exchanger (74) is sucked into the first compressor section (111) through the first suction pipe (32). In the first usage side heat exchanger (74) functioning as an evaporator, an object such as air is cooled, and in the second usage side heat exchanger (84) functioning as a condenser, an object such as air is heated. Is done.

The refrigeration apparatus (10) of the tenth invention is provided with a controller (120). When the operating capacity of the first compressor section (111) is lower than the reference capacity during the first concurrent operation, the controller (120) performs the first operation so that the refrigerant pressure in the first suction pipe (32) becomes the target low pressure. Adjust the operating capacity of the compressor section (111). Therefore, the evaporation temperature of the refrigerant in the first usage side heat exchanger (74) is maintained at the saturation temperature corresponding to the target low pressure.

In an eleventh aspect based on the tenth aspect, the controller (120) is configured such that the operating capacity of the first compressor unit (111) is equal to or greater than the reference capacity during the first concurrent operation. The first compressor part (111) and the second compressor part (112) are maintained so that the control valve (48) is fully opened and the refrigerant pressure in the first suction pipe (32) becomes the target low pressure. This adjusts the operating capacity.

If the operating capacity of the first compressor section (111) is greater than or equal to the reference capacity during the first concurrent operation, the cooling load in the first use side heat exchanger (74) is limited only by the first compressor section (111). It cannot be processed, or it is not appropriate to process the cooling load in the first use side heat exchanger (74) only by the first compressor section (111). Therefore, in this case, the controller (120) of the eleventh aspect of the invention maintains the control valve (48) in a fully open state, and the first compressor section so that the refrigerant pressure in the first suction pipe (32) becomes the target low pressure. (111) and the operating capacity of the second compressor section (112) are adjusted. In this case, a part of the refrigerant evaporated in the first use side heat exchanger (74) is sucked into the first compressor section (111), and the rest passes through the connection pipe (47) to the second compressor. Inhaled into the part (112). For this reason, the cooling load in the 1st utilization side heat exchanger (74) is processed by both the 1st compressor part (111) and the 2nd compressor part (112).

In a twelfth aspect based on the first aspect, the heat source side heat exchanger (26) is stopped, the second usage side heat exchanger (84) functions as a condenser, and the first usage side heat is The exchanger (74) can execute the second coexistence operation in which the evaporator functions as an evaporator, and the operation capacities of the first compressor unit (111) and the second compressor unit (112) and the control valve (48 ), And the controller (120) has an operating capacity of the first compressor part (111) below a predetermined reference capacity during the second concurrent operation. In this case, the operating capacity of the first compressor unit (111) is adjusted so that the control valve (48) is kept in a fully closed state and the refrigerant pressure in the first suction pipe (32) becomes a predetermined target low pressure. The second compressor section (112) is kept in a stopped state.

The refrigeration apparatus (10) of the twelfth invention can execute the second concurrent operation. During the second concurrent operation, the refrigerant discharged from the first compressor unit (111) is supplied to the second usage-side heat exchanger (84) and evaporated in the first usage-side heat exchanger (74). Is sucked into the first compressor section (111) through the first suction pipe (32). In the first usage side heat exchanger (74) functioning as an evaporator, an object such as air is cooled, and in the second usage side heat exchanger (84) functioning as a condenser, an object such as air is heated. Is done.

The refrigeration apparatus (10) of the twelfth invention is provided with a controller (120). When the operation capacity of the first compressor unit (111) is lower than the predetermined reference capacity during the second concurrent operation, the controller (120) keeps the control valve (48) in the fully closed state, and the first suction pipe ( The operating capacity of the first compressor section (111) is adjusted so that the refrigerant pressure of 32) becomes a predetermined target low pressure. Therefore, the evaporation temperature of the refrigerant in the first usage side heat exchanger (74) is maintained at the saturation temperature corresponding to the target low pressure.

In a thirteenth aspect based on the twelfth aspect, the controller (120) is configured such that the operating capacity of the first compressor unit (111) is equal to or greater than the reference capacity during the second concurrent operation. The control valve (48) is kept fully open, and the operating capacity of the second compressor section (112) is adjusted so that the refrigerant pressure in the first suction pipe (32) becomes the target low pressure.

If the operating capacity of the first compressor section (111) is greater than or equal to the reference capacity during the second concurrent operation, the cooling load in the first usage side heat exchanger (74) is limited only by the first compressor section (111). It cannot be processed, or it is not appropriate to process the cooling load in the first use side heat exchanger (74) only by the first compressor section (111). Therefore, in this case, the controller (120) according to the thirteenth aspect of the invention maintains the control valve (48) in a fully opened state, and the first compressor section so that the refrigerant pressure in the first suction pipe (32) becomes the target low pressure. (111) and the operating capacity of the second compressor section (112) are adjusted. In this case, a part of the refrigerant evaporated in the first use side heat exchanger (74) is sucked into the first compressor section (111), and the rest passes through the connection pipe (47) to the second compressor. Inhaled into the part (112). For this reason, the cooling load in the 1st utilization side heat exchanger (74) is processed by both the 1st compressor part (111) and the 2nd compressor part (112).

In a fourteenth aspect based on the first aspect, the second use side heat exchanger (84) functions as a condenser, and the heat source side heat exchanger (26) and the first use side heat exchanger ( 74) can execute the third coexistence operation functioning as an evaporator, and the operation capacity of the first compressor unit (111) and the second compressor unit (112) and the opening of the control valve (48). A controller (120) for adjusting the degree, the controller (120), when the operating capacity of the first compressor unit (111) is below a predetermined reference capacity during the third concurrent operation, The control valve (48) is kept fully closed, the operating capacity of the first compressor unit (111) is adjusted so that the refrigerant pressure in the first suction pipe (32) becomes a predetermined target low pressure, The operating capacity of the second compressor section (112) is adjusted so that the refrigerant condensing temperature in the second usage side heat exchanger (84) becomes a predetermined target temperature. It is intended to.

The refrigeration apparatus (10) of the fourteenth invention can execute the third coexistence operation. During the third concurrent operation, the refrigerant discharged from the first compressor unit (111) and the second compressor unit (112) is supplied to the second usage side heat exchanger (84), and the first usage side heat is supplied. The refrigerant evaporated in the exchanger (74) passes through the first suction pipe (32) and is sucked into the first compressor section (111), and the refrigerant evaporated in the heat source side heat exchanger (26) flows into the second suction pipe ( 34) and is sucked into the second compressor section (112). In the first usage side heat exchanger (74) functioning as an evaporator, an object such as air is cooled, and in the second usage side heat exchanger (84) functioning as a condenser, an object such as air is heated. Is done.

The refrigeration apparatus (10) of the fourteenth invention is provided with a controller (120). When the operating capacity of the first compressor unit (111) is lower than the predetermined reference capacity during the third concurrent operation, the controller (120) keeps the control valve (48) in a fully closed state, The operating capacity of the first compressor unit (111) is adjusted so that the refrigerant pressure of 32) becomes a predetermined target low pressure, and the refrigerant condensing temperature in the second use side heat exchanger (84) becomes the target temperature. Thus, the operating capacity of the second compressor section (112) is adjusted. Therefore, the evaporation temperature of the refrigerant in the first usage side heat exchanger (74) is maintained at the saturation temperature corresponding to the target low pressure, and the condensation temperature of the refrigerant in the second usage side heat exchanger (84) is maintained at the target temperature. It is.

In a fifteenth aspect based on the fourteenth aspect, the controller (120) is configured such that the operating capacity of the first compressor unit (111) is equal to or greater than the reference capacity during the third concurrent operation. The control valve (48) is kept fully open, and the operating capacity of the second compressor section (112) is adjusted so that the refrigerant pressure in the first suction pipe (32) becomes the target low pressure.

If the operating capacity of the first compressor section (111) is greater than or equal to the reference capacity during the third concurrent operation, the cooling load in the first use side heat exchanger (74) is reduced only by the first compressor section (111). It cannot be processed, or it is not appropriate to process the cooling load in the first use side heat exchanger (74) only by the first compressor section (111). Therefore, in this case, the controller (120) of the fifteenth aspect of the invention maintains the control valve (48) in a fully open state, and the first compressor section so that the refrigerant pressure in the first suction pipe (32) becomes the target low pressure. (111) and the operating capacity of the second compressor section (112) are adjusted. In this case, a part of the refrigerant evaporated in the first use side heat exchanger (74) is sucked into the first compressor section (111), and the rest passes through the connection pipe (47) to the second compressor. Inhaled into the part (112). For this reason, the cooling load in the 1st utilization side heat exchanger (74) is processed by both the 1st compressor part (111) and the 2nd compressor part (112).

In a sixteenth aspect based on the first aspect, the second use side heat exchanger (84) functions as a condenser, the heat source side heat exchanger (26) functions as an evaporator, A heating operation in which the use-side heat exchanger (74) is stopped can be executed, and the operating capacities of the first compressor unit (111) and the second compressor unit (112) and the control valve (48) A controller (120) for adjusting the opening degree, and the controller (120) is configured so that the operating capacity of the second compressor section (112) is lower than a predetermined reference capacity during the heating operation. Keeping the control valve (48) in a fully closed state, the operating capacity of the second compressor section (112) is set so that the refrigerant condensing temperature in the second use side heat exchanger (84) becomes a predetermined target temperature. To adjust.

The refrigeration apparatus (10) of the sixteenth invention can execute a heating operation. During the heating operation, the refrigerant discharged from the second compressor section (112) is supplied to the second use side heat exchanger (84), and the refrigerant evaporated in the heat source side heat exchanger is supplied to the second suction pipe ( 34) and is sucked into the second compressor section (112). In the second usage side heat exchanger (84) functioning as a condenser, an object such as air is heated.

The refrigeration apparatus (10) of the sixteenth invention is provided with a controller (120). When the operation capacity of the second compressor section (112) is lower than the predetermined reference capacity during the heating operation, the controller (120) keeps the control valve (48) in the fully closed state, and the second use side heat exchanger The operating capacity of the second compressor section (112) is adjusted so that the refrigerant condensing temperature in (84) becomes the target temperature. Therefore, the refrigerant condensing temperature in the second usage side heat exchanger (84) is maintained at the target temperature.

In a seventeenth aspect based on the sixteenth aspect, the controller (120) causes the control valve (120) when the operating capacity of the second compressor section (112) becomes equal to or greater than the reference capacity during the heating operation. 48) is fully opened, and the operating capacity of the first compressor unit (111) is adjusted such that the condensation temperature of the refrigerant in the second usage side heat exchanger (84) becomes the target temperature.

If the operating capacity of the second compressor section (112) is greater than or equal to the reference capacity during the heating operation, the heating load in the second usage side heat exchanger (84) is processed only by the second compressor section (112). Or it is not appropriate to process the heating load in the second usage side heat exchanger (84) only by the second compressor section (112). Therefore, in this case, the controller (120) of the seventeenth aspect of the invention keeps the control valve (48) fully open so that the refrigerant condensing temperature in the second usage side heat exchanger (84) becomes the target temperature. The operating capacities of the first compressor part (111) and the second compressor part (112) are adjusted. In this case, a part of the refrigerant evaporated in the heat source side heat exchanger (26) is sucked into the first compressor part (111) and the rest is sucked into the second compressor part (112), and the first compressor part The refrigerant discharged from (111) and the second compressor section (112) is supplied to the second usage side heat exchanger (84). For this reason, the heating load in the 2nd utilization side heat exchanger (84) is processed by both the 1st compressor part (111) and the 2nd compressor part (112).

In the refrigeration apparatus (10) of the present invention, the connection pipe (47) for connecting the first suction pipe (32) and the second suction pipe (34) is provided in the refrigerant circuit (11), and the opening degree variable control valve. (48) is provided in the connecting pipe (47). For this reason, the refrigeration apparatus (10) of the present invention provides the first suction pipe when the flow rate of the refrigerant required in the first usage-side heat exchanger (74) cannot be secured by the first compressor section (111) alone. The refrigerant flowing through (32) can be sucked into both the first compressor part (111) and the second compressor part (112). Further, the refrigeration apparatus (10) of the present invention is configured so that the second suction pipe (10) can be used when the refrigerant flow rate required in the second usage-side heat exchanger (84) cannot be secured by the second compressor section (112) alone. 34) can be sucked into both the first compressor part (111) and the second compressor part (112).

When the refrigerant flowing through the first suction pipe (32) is sucked into both the first compressor part (111) and the second compressor part (112), the opening degree of the control valve (48) should be changed. Thus, it is possible to adjust the flow rate of the refrigerant sucked into the second compressor section (112) through the connection pipe (47). In this case, by adjusting the opening of the control valve (48), the flow rate of the refrigerant flowing through the first usage side heat exchanger (74) is changed to the cooling load in the first usage side heat exchanger (74). In other words, it is possible to set an appropriate value according to the amount of heat that the refrigerant should absorb in the first usage-side heat exchanger (74) per unit time.

Further, when the refrigerant flowing through the second suction pipe (34) is sucked into both the first compressor part (111) and the second compressor part (112), the opening degree of the control valve (48) is changed. By doing so, the flow rate of the refrigerant drawn into the first compressor part (111) through the connection pipe (47) can be adjusted. In this case, by adjusting the opening of the control valve (48), the flow rate of the refrigerant flowing through the second usage side heat exchanger (84) is changed to the cooling load in the second usage side heat exchanger (84). In other words, it is possible to set an appropriate value according to the amount of heat that the refrigerant should absorb in the second usage-side heat exchanger (84) per unit time.

As described above, in the present invention, when the flow rate of the refrigerant required in the first usage-side heat exchanger (74) cannot be ensured only by the first compressor section (111), the opening degree of the control valve (48) is increased. By adjusting, the flow rate of the refrigerant flowing through the first usage-side heat exchanger (74) can be set to a value corresponding to the cooling load in the first usage-side heat exchanger (74). In the present invention, the opening of the control valve (48) is adjusted when the flow rate of the refrigerant required in the second usage side heat exchanger (84) cannot be secured by the second compressor section (112) alone. Thus, the flow rate of the refrigerant flowing through the second usage-side heat exchanger (84) can be set to a value corresponding to the cooling load in the second usage-side heat exchanger (84). Therefore, according to the present invention, the cooling capacity of the refrigeration apparatus (10) can be appropriately controlled, and the usability of the refrigeration apparatus (10) can be improved.

In the second aspect, the refrigeration apparatus (10) can execute a first cooling operation in which the first usage-side heat exchanger (74) and the second usage-side heat exchanger (84) function as an evaporator. . When the operating capacities of the first compressor part (111) and the second compressor part (112) are below the reference capacity during the first cooling operation, the controller (120) While maintaining the closed state, the operating capacity of the first compressor section (111) is adjusted based on the refrigerant pressure in the first suction pipe (32), and the operating capacity of the second compressor section (112) is adjusted to the second suction pipe ( 34) Adjust based on the refrigerant pressure. For this reason, the cooling load in the first usage-side heat exchanger (74) can be processed only by the first compressor section (111), and the cooling load in the second usage-side heat exchanger (84) is subjected to the second compression. When the processing can be performed only by the machine unit (112), the operation capacities of the first compressor unit (111) and the second compressor unit (112) can be appropriately controlled.

Further, the controller (120) of the second invention is configured so that the refrigerant pressure in the second suction pipe (34) is higher than the refrigerant pressure in the first suction pipe (32). And the operating capacity of the second compressor section (112). Therefore, according to this invention, the evaporating temperature of the refrigerant in the second usage side heat exchanger (84) can be set higher than the evaporating temperature of the refrigerant in the first usage side heat exchanger (74).

In the controller (120) of the third invention, the operating capacity of the first compressor unit (111) is lower than the reference capacity during the first cooling operation, and the operating capacity of the second compressor unit (112) is the reference capacity. When it is above, the predetermined | prescribed operation | movement which adjusts the opening degree of a control valve (48) and the operating capacity of a 1st compressor part (111) is performed. For this reason, a part of cooling load in the 2nd utilization side heat exchanger (84) can be processed by the 1st compressor part (111) in which operation capacity is less than standard capacity. Therefore, according to the present invention, the cooling load in the first usage-side heat exchanger (74) and the cooling load in the second usage-side heat exchanger (84) are divided into the first compressor section (111) and the second It can process reliably using a compressor part (112).

When the operating capacity of the first compressor part (111) and the second compressor part (112) is greater than or equal to a predetermined reference capacity during the first cooling operation, the controller (120) of the fourth invention described above, The opening degree of the adjustment valve (48) is adjusted so that the refrigerant pressure in the first suction pipe (32) becomes the first target low pressure. For this reason, the flow volume of the refrigerant | coolant which can be suck | inhaled from the 1st suction pipe (32) by the 1st compressor part (111) can be ensured, and the raise of the refrigerant pressure of the 1st suction pipe (32) can be suppressed. Therefore, according to this invention, it is possible to suppress an increase in the evaporation temperature of the refrigerant in the first usage-side heat exchanger (74).

In the fifth aspect, the refrigeration apparatus (10) performs the second cooling operation in which the first usage-side heat exchanger (74) is stopped and the second usage-side heat exchanger (84) functions as an evaporator. Is possible. When the operation capacity of the second compressor section (112) falls below the reference capacity during the second cooling operation, the controller (120) keeps the control valve (48) in a fully closed state, and the second suction pipe ( The operating capacity of the second compressor section (112) is adjusted so that the refrigerant pressure of 34) becomes the second target low pressure. Therefore, according to this invention, the operating capacity of the second compressor section (112) can be appropriately adjusted according to the cooling load in the second usage side heat exchanger (84).

Here, in the refrigeration apparatus (10), a signal indicating that the first use side heat exchanger (74) has resumed operation may not be input to the controller (120). In this case, the controller (120) performs an operation for setting the refrigerant pressure in the first suction pipe (32) to a pressure different from the first target low pressure while the first user-side heat exchanger (74) is stopped. Then, even after the first usage side heat exchanger (74) resumes operation, the refrigerant pressure in the first suction pipe (32) is maintained at a pressure different from the first target low pressure. The object cannot be sufficiently cooled in the exchanger (74).

On the other hand, according to the sixth aspect of the present invention, the first intake pipe ( The refrigerant pressure of 32) can be maintained at the first target low pressure. Therefore, according to this invention, even if it is a case where the signal which shows that the 1st utilization side heat exchanger (74) restarted operation | movement is not input into a controller (120), a 1st utilization side heat exchanger ( The object can be reliably cooled after 74) resumes operation.

The controller (120) according to the seventh aspect of the invention is such that, during the second cooling operation, when the operation capacities of the first compressor unit (111) and the second compressor unit (112) are equal to or greater than a predetermined reference capacity, The opening degree of the adjustment valve (48) is adjusted so that the refrigerant pressure in the first suction pipe (32) becomes the first target low pressure. For this reason, also in this case, the refrigerant pressure in the first suction pipe (32) can be maintained at the first target low pressure, and the object is reliably cooled after the first use side heat exchanger (74) resumes operation. be able to.

In the eighth aspect of the invention, the refrigeration apparatus (10) performs the third cooling operation in which the first usage side heat exchanger (74) functions as an evaporator and the second usage side heat exchanger (84) pauses. Is possible. When the operating capacity of the first compressor unit (111) is lower than the reference capacity during the third cooling operation, the controller (120) keeps the control valve (48) in a fully closed state, The operating capacity of the first compressor section (111) is adjusted so that the refrigerant pressure of 32) becomes the first target low pressure. Therefore, according to this invention, the operating capacity of the first compressor section (111) can be appropriately adjusted according to the cooling load in the first usage-side heat exchanger (74).

The controller (120) of the ninth aspect of the invention maintains the control valve (48) in a fully opened state when the operating capacity of the first compressor section (111) is equal to or greater than the reference capacity during the third cooling operation, The operating capacity of the first compressor part (111) and the second compressor part (112) is adjusted. For this reason, a part of the cooling load in the first use side heat exchanger (74) is not limited to the first compressor part (111) whose operating capacity is equal to or higher than the reference capacity, but also the second compressor part (112 ) Can also be processed. Therefore, according to this invention, the cooling load in the first usage-side heat exchanger (74) can be reliably processed using the first compressor part (111) and the second compressor part (112).

In the tenth aspect of the invention, the refrigeration apparatus (10) includes a heat source side heat exchanger (26) and a second usage side heat exchanger (84) functioning as a condenser, and a first usage side heat exchanger (74). Is capable of performing the first coexistence operation that functions as an evaporator. When the operating capacity of the first compressor unit (111) is lower than the reference capacity during the first concurrent operation, the controller (120) causes the refrigerant pressure in the first suction pipe (32) to be the target low pressure. The operating capacity of the first compressor section (111) is adjusted. For this reason, the evaporating temperature of the refrigerant in the first usage-side heat exchanger (74) can be maintained at a saturation temperature corresponding to the target low pressure, and the object is reliably cooled in the first usage-side heat exchanger (74). it can.

The controller (120) of the eleventh aspect of the invention maintains the control valve (48) in a fully open state when the operating capacity of the first compressor section (111) is equal to or greater than the reference capacity during the first concurrent operation. The operating capacities of the first compressor unit (111) and the second compressor unit (112) are adjusted so that the refrigerant pressure in the first suction pipe (32) becomes the target low pressure. For this reason, the cooling load in the first usage-side heat exchanger (74) can be processed by both the first compressor unit (111) and the second compressor unit (112), and the first usage-side heat exchanger The cooling capacity obtained in (74) can be sufficiently secured.

In the twelfth aspect of the invention, the refrigeration apparatus (10) is a second coexistence in which the second usage-side heat exchanger (84) functions as a condenser and the first usage-side heat exchanger (74) functions as an evaporator. Operation can be performed. When the operation capacity of the first compressor unit (111) is lower than the reference capacity during the second concurrent operation, the controller (120) causes the refrigerant pressure in the first suction pipe (32) to become the target low pressure. The operating capacity of the first compressor section (111) is adjusted. For this reason, the evaporating temperature of the refrigerant in the first usage-side heat exchanger (74) can be maintained at a saturation temperature corresponding to the target low pressure, and the object is reliably cooled in the first usage-side heat exchanger (74). it can.

The controller (120) of the thirteenth aspect of the present invention maintains the control valve (48) in a fully open state when the operating capacity of the first compressor section (111) is equal to or greater than the reference capacity during the second concurrent operation. The operating capacities of the first compressor unit (111) and the second compressor unit (112) are adjusted so that the refrigerant pressure in the first suction pipe (32) becomes the target low pressure. For this reason, the cooling load in the first usage-side heat exchanger (74) can be processed by both the first compressor unit (111) and the second compressor unit (112), and the first usage-side heat exchanger The cooling capacity obtained in (74) can be sufficiently secured.

In the fourteenth aspect of the invention, the refrigeration apparatus (10) has the second use side heat exchanger (84) functioning as a condenser, and the heat source side heat exchanger (26) and the first use side heat exchanger (74). The third coexisting operation that functions as an evaporator can be executed. When the operation capacity of the first compressor unit (111) is lower than the reference capacity during the third concurrent operation, the controller (120) causes the refrigerant pressure in the first suction pipe (32) to be the target low pressure. The operating capacity of the first compressor section (111) is adjusted. For this reason, the evaporating temperature of the refrigerant in the first usage-side heat exchanger (74) can be maintained at a saturation temperature corresponding to the target low pressure, and the object is reliably cooled in the first usage-side heat exchanger (74). it can.

The controller (120) of the fifteenth aspect of the invention maintains the control valve (48) in a fully opened state when the operating capacity of the first compressor section (111) is equal to or greater than the reference capacity during the third concurrent operation, The operating capacities of the first compressor unit (111) and the second compressor unit (112) are adjusted so that the refrigerant pressure in the first suction pipe (32) becomes the target low pressure. For this reason, the cooling load in the first usage-side heat exchanger (74) can be processed by both the first compressor unit (111) and the second compressor unit (112), and the first usage-side heat exchanger The cooling capacity obtained in (74) can be sufficiently secured.

In the sixteenth aspect of the invention, the refrigeration apparatus (10) can execute a heating operation in which the second use side heat exchanger (84) functions as a condenser and the heat source side heat exchanger (26) functions as an evaporator. It is. When the operation capacity of the second compressor section (112) is lower than the reference capacity during the heating operation, the controller (120) indicates that the refrigerant condensing temperature in the second usage side heat exchanger (84) is equal to the target temperature. The operating capacity of the second compressor section (112) is adjusted so that For this reason, the condensation temperature of the refrigerant in the second usage side heat exchanger (84) can be maintained at the target temperature, and the object can be reliably heated in the second usage side heat exchanger (84).

The controller (120) according to the seventeenth aspect of the present invention maintains the control valve (48) in a fully open state when the operating capacity of the second compressor section (112) is equal to or greater than the reference capacity during the heating operation, The operating capacities of the first compressor unit (111) and the second compressor unit (112) are adjusted so that the refrigerant condensing temperature in the use side heat exchanger (84) becomes the target temperature. For this reason, the heating load in the second usage side heat exchanger (84) can be processed by both the first compressor unit (111) and the second compressor unit (112), and the second usage side heat exchanger The heating ability obtained in (84) can be sufficiently secured.

FIG. 1 is a piping diagram illustrating the configuration of the refrigeration apparatus according to the first embodiment. FIG. 2 is a piping system diagram showing the configuration of the refrigeration apparatus of Embodiment 1, and shows the flow of the refrigerant during the first cooling operation. FIG. 3 is a piping system diagram showing the configuration of the refrigeration apparatus of Embodiment 1, and shows the flow of the refrigerant during the second cooling operation. FIG. 4 is a piping system diagram showing the configuration of the refrigeration apparatus of Embodiment 1, and shows the flow of the refrigerant during the third cooling operation. FIG. 5 is a piping system diagram showing the configuration of the refrigeration apparatus of Embodiment 1, and shows the flow of the refrigerant during the first concurrent operation. FIG. 6 is a piping system diagram showing the configuration of the refrigeration apparatus of Embodiment 1, and shows the flow of refrigerant during the second concurrent operation. FIG. 7 is a piping system diagram showing the configuration of the refrigeration apparatus of Embodiment 1, and shows the flow of the refrigerant during the third concurrent operation. FIG. 8 is a piping system diagram showing the configuration of the refrigeration apparatus of Embodiment 1, and shows the flow of refrigerant during heating operation. FIG. 9 is a flowchart illustrating an operation performed by the controller of the first embodiment during the cooling / cooling operation. FIG. 10 is a flowchart illustrating a first control operation performed by the controller of the first embodiment during the first cooling operation. FIG. 11 is a flowchart illustrating a second control operation performed by the controller of the first embodiment during the second cooling operation. FIG. 12 is a flowchart showing an operation performed by the controller of the first embodiment during the cooling / heating operation. FIG. 13 is a flowchart illustrating an operation performed by the controller of the first embodiment during the first concurrent operation. FIG. 14 is a flowchart illustrating an operation performed by the controller of the first embodiment during the second concurrent operation. FIG. 15 is a flowchart illustrating a first control operation performed by the controller of the modification of the first embodiment during the first cooling operation. FIG. 16 is a flowchart illustrating an operation performed by the controller of the second embodiment during the cooling / cooling operation. FIG. 17 is a flowchart illustrating a first control operation performed by the controller of the second embodiment during the first cooling operation. FIG. 18 is a flowchart illustrating a first control operation performed by the controller of the second embodiment during the second cooling operation. FIG. 19 is a flowchart illustrating an operation performed by the controller of the second embodiment during the cooling / heating operation. FIG. 20 is a flowchart illustrating an operation performed by the controller of the second embodiment during the first concurrent operation. FIG. 21 is a flowchart illustrating an operation performed by the controller of the second embodiment during the second concurrent operation. FIG. 22 is a piping system diagram showing a configuration of a refrigeration apparatus according to another embodiment.

Embodiments of the present invention will be described in detail with reference to the drawings. Note that the embodiments and modifications described below are essentially preferable examples, and are not intended to limit the scope of the present invention, its application, or its use.

Embodiment 1 of the Invention
A first embodiment of the present invention will be described. The refrigeration apparatus (10) of this embodiment is installed, for example, in a convenience store. And this freezing apparatus (10) is comprised so that the cooling in the store | warehouse | chamber of the refrigerated showcase for displaying food etc. and the air conditioning in a shop may be performed simultaneously.

<Overall configuration of refrigeration equipment>
As shown in FIG. 1, the refrigeration apparatus (10) includes an outdoor unit (20), a refrigeration unit (70) that is a refrigeration showcase, an air conditioning unit (80), and a controller (120). . The outdoor unit (20) is provided with an outdoor circuit (21). The refrigeration unit (70) is provided with a refrigeration circuit (71). The air conditioning unit (80) is provided with an air conditioning circuit (81).

The outdoor circuit (21) is provided with a refrigeration side liquid closing valve (12), a refrigeration side gas closing valve (13), an air conditioning side liquid closing valve (14), and an air conditioning side gas closing valve (15). The refrigeration side liquid closing valve (12) is connected to the liquid side end of the refrigeration circuit (71) via the first connection pipe (16). The refrigeration side gas shut-off valve (13) is connected to the gas side end of the refrigeration circuit (71) via the second communication pipe (17). The air conditioning side liquid closing valve (14) is connected to the liquid side end of the air conditioning circuit (81) via the third connection pipe (18). The air conditioning side gas shut-off valve (15) is connected to the gas side end of the air conditioning circuit (81) via the fourth connecting pipe (19).

In the refrigeration apparatus (10), the refrigerant circuit (11) is configured by connecting the refrigeration circuit (71) and the air conditioning circuit (81) to the outdoor circuit (21) via the connecting pipes (16 to 19). The refrigerant circuit (11) performs a vapor compression refrigeration cycle by circulating the filled refrigerant.

Note that the refrigeration apparatus (10) of the present embodiment may be provided with a plurality of refrigeration units (70). In this case, in the refrigerant circuit (11), the plurality of refrigeration circuits (71) are connected in parallel to each other. That is, as for a some refrigeration circuit (71), each liquid side edge part is connected to the 1st communication piping (16), and each gas side edge part is connected to the 2nd communication piping (17).

Also, the refrigeration apparatus (10) of the present embodiment may be provided with a plurality of air conditioning units (80). In this case, in the refrigerant circuit (11), the plurality of air conditioning circuits (81) are connected in parallel to each other. That is, as for a some air conditioning circuit (81), each liquid side edge part is connected to the 3rd connection piping (18), and each gas side edge part is connected to the 4th connection piping (19).

<Outdoor unit>
The outdoor unit (20) includes an outdoor circuit (21) and an outdoor fan (23). The outdoor circuit (21) includes a first compressor (24) constituting the first compressor section (111), a second compressor (25) constituting the second compressor section (112), and a heat source side. An outdoor heat exchanger (26) which is a heat exchanger, a first four-way switching valve (27), a second four-way switching valve (28), a liquid receiver (29), and a supercooling unit (50) It is connected. Each of the first compressor section (111) and the second compressor section (112) of the present embodiment is configured by a single compressor (24, 25).

The first compressor (24) and the second compressor (25) are both scroll-type hermetic compressors. Although not shown, in these compressors (24, 25), a compression mechanism that is a scroll type fluid machine and an electric motor that drives the compression mechanism are housed in a sealed container-like casing.

A first discharge pipe (31) and a first suction pipe (32) are connected to the first compressor (24). The first discharge pipe (31) connects the discharge portion of the first compressor (24) to a first port of a first four-way switching valve (27) described later. The first suction pipe (32) connects the suction part of the first compressor (24) to the refrigeration side gas shut-off valve (13).

A second discharge pipe (33) and a second suction pipe (34) are connected to the second compressor (25). The second discharge pipe (33) connects the discharge portion of the second compressor (25) to the first port of the first four-way switching valve (27) described later. The second suction pipe (34) connects the suction portion of the second compressor (25) to a second port of a second four-way switching valve (28) described later.

AC is supplied to the motor of each compressor (24, 25) via an inverter. Changing the output frequency of the inverter (that is, the operating frequency of the compressor) changes the rotational speed of the motor of each compressor (24, 25), resulting in a change in the operating capacity of the compressor (24, 25). . Specifically, increasing the operating frequency of the compressor (24, 25) increases the operating capacity of the compressor (24, 25), and decreasing the operating frequency of the compressor (24, 25) reduces the compressor ( 24,25) The operating capacity is reduced. When the operating capacity of the first compressor (24) changes, the operating capacity of the first compressor section (111) changes, and when the operating capacity of the second compressor (25) changes, the second compressor section (112 ) Operating capacity changes.

The outdoor heat exchanger (26) is a fin-and-tube heat exchanger. An outdoor fan (23) for supplying outdoor air to the outdoor heat exchanger (26) is installed in the vicinity of the outdoor heat exchanger (26). The outdoor heat exchanger (26) exchanges heat between the refrigerant in the refrigerant circuit (11) and outdoor air.

The first four-way switching valve (27) has a first port connected to the first discharge pipe (31) and the second discharge pipe (33) and a second port connected to the fourth port of the second four-way switch valve (28). A port, a third port connected to the gas side end of the outdoor heat exchanger (26), and a fourth port connected to the gas side end of the air conditioning heat exchanger (84). The second four-way switching valve (28) includes a first port connected to the first discharge pipe (31) and the second discharge pipe (33), a second port connected to the second suction pipe (34), and a seal And a fourth port connected to the second port of the first four-way switching valve (27).

Each four-way switching valve (27, 28) has a first state (state indicated by a solid line in FIG. 1) in which the first port and the third port communicate with each other and the second port and the fourth port communicate with each other, It is configured to be switchable to a second state (state indicated by a broken line in FIG. 1) in which the fourth port communicates and the second port communicates with the third port. In the first four-way switching valve (27) and the second four-way switching valve (28), the second suction pipe (34) communicates with the air conditioning heat exchanger (84) and the second suction pipe (34) is in outdoor heat. A switching mechanism (110) for switching between a state communicating with the exchanger (26) is configured.

The liquid receiver (29) is a sealed container in which excess refrigerant is stored. A first liquid pipe (41), a second liquid pipe (42), and a gas vent pipe (36) are connected to the liquid receiver (29).

The first liquid pipe (41) has one end connected to the liquid side end of the outdoor heat exchanger (26) and the other end connected to the top of the liquid receiver (29). The second liquid pipe (42) has one end connected to the bottom of the liquid receiver (29) and the other end connected to the supercooling heat exchanger (51). The gas vent pipe (36) has one end connected to the top of the liquid receiver (29) and the other end connected to the relay pipe (57) of the injection circuit (55).

The supercooling unit (50) cools the refrigerant supplied to the refrigeration unit (70). The supercooling unit (50) has a supercooling heat exchanger (51) and an injection circuit (55). The supercooling heat exchanger (51) has a cooling side channel (52) and an evaporation side channel (53). The cooling side flow path (52) has an inflow end connected to the second liquid pipe (42) and an outflow end connected to the refrigeration side liquid pipe (37). The evaporation side channel (53) constitutes a part of the injection circuit (55). In the supercooling heat exchanger (51), the high-pressure liquid refrigerant flowing through the cooling side flow path (52) and the intermediate pressure refrigerant flowing through the evaporation side flow path (53) exchange heat.

The injection circuit (55) introduces a medium-pressure refrigerant into each compressor (24, 25). The injection circuit (55) has an inflow portion connected to the refrigeration side liquid pipe (37), and an outflow portion branched into two and connected to an intermediate pressure portion of each compressor (24, 25). Specifically, the injection circuit (55) includes one inflow pipe (56) connected to the inflow portion of the evaporation side flow path (53) and one line connected to the outflow portion of the evaporation side flow path (53). It has a relay pipe (57) and two introduction pipes (58, 59) branched from the outflow part of the relay pipe (57).

The pressure reducing valve (60) for reducing the high pressure liquid refrigerant to an intermediate pressure is connected to the inflow pipe (56). The pressure reducing valve (60) is an electronic expansion valve having a variable opening. The two introduction pipes (58, 59) are connected to a compression chamber in the middle of compression of the first compressor (24) and a compression chamber in the middle of compression of the second compressor (25). And a second introduction pipe (59) connected to the. The first introduction pipe (58) is provided with a first injection valve (61), and the second introduction pipe (59) is provided with a second injection valve (62). Each injection valve (61, 62) is an electronic expansion valve with a variable opening, and adjusts the flow rate of the intermediate-pressure refrigerant introduced into each compressor (24, 25).

The outdoor circuit (21) is provided with a refrigeration side liquid pipe (37), an air conditioning side liquid pipe (38), a third liquid pipe (43), a fourth liquid pipe (44), and a fifth liquid pipe (45). It has been. One end of the refrigeration side liquid pipe (37) is connected to the refrigeration side liquid closing valve (12), and the other end is connected to the cooling side flow path (52) of the supercooling heat exchanger (51). The air conditioning side liquid pipe (38) has one end connected to the air conditioning side liquid closing valve (14) and the other end connected to the second liquid pipe (42). The air conditioning side liquid pipe (38) is provided with a liquid side expansion valve (49). The third liquid pipe (43) has one end connected to the air conditioning side liquid pipe (38) and the other end connected to the first liquid pipe (41). The fourth liquid pipe (44) has one end connected to the refrigeration side liquid pipe (37) and the other end connected to the first liquid pipe (41). The fourth liquid pipe (44) is provided with an outdoor expansion valve (39). The liquid side expansion valve (49) and the outdoor expansion valve (39) are electronic expansion valves each having a variable opening. The fifth liquid pipe (45) has one end connected to the first liquid pipe (41) and the other end connected to the fourth liquid pipe (44).

The outdoor circuit (21) is provided with six check valves (CV1 to CV5). The first check valve (CV1) is connected to the first discharge pipe (31), the second check valve (CV2) is connected to the second discharge pipe (33), and the third check valve (CV3) is connected to the first liquid pipe (CV1). 41), the fourth check valve (CV4) is in the third liquid pipe (43), the fifth check valve (CV5) is in the fourth liquid pipe (44), and the sixth check valve (CV6) is in the It is provided in each of the five liquid pipes (45). These check valves (CV1 to CV6) allow the flow of refrigerant in the direction of the arrow shown in FIG. 1, and prohibit the flow of refrigerant in the opposite direction.

The outdoor circuit (21) is provided with two solenoid valves (SV1, SV2). The first solenoid valve (SV1) is provided on the upstream side of the third check valve (CV3) in the first liquid pipe (41). The second solenoid valve (SV2) is provided in the gas vent pipe (36). These solenoid valves (SV1, SV2) are open / close valves that switch between an open state and a closed state.

The outdoor circuit (21) is provided with a connecting pipe (47) and a flow control valve (48). The connection pipe (47) has one end connected to the first suction pipe (32) and the other end connected to the second suction pipe (34). The flow control valve (48) is provided in the connection pipe (47). The flow rate control valve (48) is an electronic expansion valve with a variable opening. That is, the flow rate adjusting valve (48) includes a pulse motor for driving the valve body, and the opening degree thereof is changed by moving the valve body.

Various sensors are provided in the outdoor circuit (21).

The first discharge pipe (31) includes a first discharge temperature sensor (90) that detects the temperature of refrigerant discharged from the first compressor (24), and a discharge that detects refrigerant pressure in the first discharge pipe (31). And a pressure sensor (91).

The second discharge pipe (33) is provided with a second discharge temperature sensor (92) for detecting the temperature of the refrigerant discharged from the second compressor (25).

In the first suction pipe (32), a first suction temperature sensor (93) for detecting the temperature of the refrigerant sucked in the first compressor (24) and a refrigerant pressure LP1 in the first suction pipe (32) are detected. A first suction pressure sensor (94) is provided. In the first suction pipe (32), the first suction temperature sensor (93) is disposed on the downstream side of the connection position of the connection pipe (47) to the first suction pipe (32), and the first suction pressure is disposed on the upstream side. A sensor (94) is arranged.

In the second suction pipe (34), a second suction temperature sensor (95) for detecting the temperature of the refrigerant flowing through the second suction pipe (34) and a refrigerant pressure LP2 in the second suction pipe (34) are detected. A second suction pressure sensor (96) is provided. In the second suction pipe (34), the second suction temperature sensor (95) and the second suction pressure sensor (96) are arranged upstream of the connection position of the connection pipe (47) to the second suction pipe (34). ing.

An outdoor refrigerant temperature sensor (97) for detecting the refrigerant temperature is provided at the liquid side end of the outdoor heat exchanger (26). The relay pipe (57) of the injection circuit (55) is provided with an intermediate refrigerant temperature sensor (98) for detecting the refrigerant temperature and an intermediate refrigerant pressure sensor (99) for detecting the refrigerant pressure.

Also, the outdoor unit (20) is provided with an outside air temperature sensor (100). The outdoor temperature sensor (100) is disposed in the vicinity of the outdoor heat exchanger (26), and detects the temperature of the outdoor air supplied to the outdoor heat exchanger (26).

<Refrigerated unit>
The refrigeration unit (70) is a refrigerated showcase for displaying food and the like. The refrigeration unit (70) includes a refrigeration circuit (71) and an internal fan (73).

The refrigeration circuit (71) includes, in order from the gas side end toward the liquid side end, a refrigeration heat exchanger (74) that is a first use side heat exchanger, an internal expansion valve (75), 3 solenoid valves (SV3) are provided. The refrigeration heat exchanger (74) is a fin-and-tube heat exchanger. The internal expansion valve (75) is a temperature-sensitive expansion valve. The opening degree of the internal expansion valve (75) is adjusted according to the degree of superheat of the refrigerant flowing out of the refrigeration heat exchanger (74). The third solenoid valve (SV3) is switched between an open state and a closed state. Open / close valve.

The internal fan (73) is arranged near the refrigeration heat exchanger (74). The internal fan (73) supplies the air in the refrigerator of the refrigeration unit (70) to the refrigeration heat exchanger (74). The refrigeration heat exchanger (74) exchanges heat between the refrigerant in the refrigerant circuit (11) and the internal air supplied by the internal fan (73).

The refrigeration unit (70) is provided with an internal temperature sensor (101). The internal temperature sensor (101) is disposed in the vicinity of the refrigeration heat exchanger (74) and detects the temperature of the internal air supplied to the refrigeration heat exchanger (74).

The refrigeration unit (70) starts and stops based on the detection value of the internal temperature sensor (101). Specifically, the refrigeration unit (70) determines that the detection value Ts of the internal temperature sensor (101) exceeds the internal set temperature Tss by a predetermined value (for example, 0.5 ° C.) (Tss + 0.5 <Ts). Then, the third solenoid valve (SV3) is opened to operate the internal fan (73) to cool the interior. On the other hand, when the detection value Ts of the internal temperature sensor (101) falls below the set temperature Tss in the internal storage by a predetermined value (for example, 0.5 ° C.), the refrigeration unit (70) (Ts <Tss−0.5). Then, the third solenoid valve (SV3) is closed to stop the internal fan (73), and the operation for cooling the internal space is stopped.

Thus, the operation state of the refrigeration unit (70) is switched between a thermo-ON state in which the operation for cooling the interior is performed and a thermo-off state in which the operation for cooling the interior is suspended. The refrigeration unit (70) outputs a thermo signal indicating whether the operation state is the thermo ON state or the thermo OFF state to the controller (120), and outputs the thermo signal to the controller (120). On the other hand, there is a case where it does not output.

<Air conditioning unit>
The air conditioning unit (80) includes an air conditioning circuit (81) and an indoor fan (83).

The air conditioning circuit (81) is provided with an air conditioning heat exchanger (84) as a second usage side heat exchanger and an indoor expansion valve (85) in order from the gas side end to the liquid side end. . The air conditioning heat exchanger (84) is a fin-and-tube heat exchanger. The indoor expansion valve (85) is an electronic expansion valve with a variable opening.

The indoor fan (83) is arranged near the air conditioning heat exchanger (84). The indoor fan (83) supplies indoor air in the store to the air conditioning heat exchanger (84). The air conditioning heat exchanger (84) exchanges heat between the refrigerant in the refrigerant circuit (11) and room air supplied by the indoor fan (83).

The air conditioning unit (80) is provided with an indoor temperature sensor (102). The indoor temperature sensor (102) is disposed in the vicinity of the air conditioning heat exchanger (84) and detects the temperature of the indoor air supplied to the air conditioning heat exchanger (84).

The air conditioning unit (80) starts and stops based on the detected value of the indoor temperature sensor (102).

During the cooling operation, the air conditioning unit (80) detects that the detected value Tr of the indoor temperature sensor (102) exceeds the set temperature Trs in the cabinet by a predetermined value (for example, 0.5 ° C.) (Trs + 0.5 <Tr). Then, the indoor expansion valve (85) is opened, the indoor fan (83) is operated, and an operation for cooling the room is performed. On the other hand, when the detected value Tr of the indoor temperature sensor (102) falls below the set temperature Trs in the cabinet by a predetermined value (for example, 0.5 ° C.) (Tr <Trs−0.5), The indoor expansion valve (85) is closed to stop the indoor fan (83), and the operation for cooling the room is stopped.

During the heating operation, the air conditioning unit (80) detects that the detected value Tr of the indoor temperature sensor (102) is lower than the set temperature Trs in the refrigerator by a predetermined value (for example, 0.5 ° C.) (Tr <Trs−0.0. 5) The indoor expansion valve (85) is opened and the indoor fan (83) is operated to perform an operation for heating the room. On the other hand, when the detected value Tr of the indoor temperature sensor (102) exceeds the set temperature Trs in the refrigerator by a predetermined value (for example, 0.5 ° C.) (Trs + 0.5 <Tr), the air conditioning unit (80) expands indoors. The valve (85) is closed to stop the indoor fan (83), and the operation for heating the room is stopped.

Thus, the operating state of the air conditioning unit (80) is switched between a thermo-ON state in which an operation for cooling or heating the room is performed and a thermo-off state in which an operation for cooling or heating the room is suspended. The air conditioning unit (80) outputs to the controller (120) a thermo signal indicating whether the operation state is the thermo-ON state or the thermo-OFF state.

<Controller>
The controller (120) controls various devices (compressor, various valves, various fans, etc.) according to the detection values of the various sensors described above. For example, the controller (120) includes an operation for changing the operating state of the refrigeration apparatus (10) by operating the four-way switching valve (27, 28), and the first compressor unit (111) and the second compressor unit. The operation of adjusting the operating capacity of (112) and the operation of adjusting the opening of the flow rate control valve (48) are performed. The operation performed by the controller (120) will be described later.

-Driving operation-
The operation of the refrigeration apparatus (10) will be described. The refrigeration apparatus (10) selectively performs refrigeration / cooling operation and refrigeration / heating operation.

<Refrigeration / cooling operation>
The refrigeration / cooling operation is an operation for cooling the interior of the refrigeration unit (70), which is a refrigeration showcase, and cooling the room by the air conditioning unit (80). The refrigeration apparatus (10) during the refrigeration / cooling operation selectively performs the first cooling operation, the second cooling operation, and the third cooling operation.

In the refrigeration / cooling operation, the first four-way switching valve (27) is set to the first state, the second four-way switching valve (28) is set to the first state, and the first electromagnetic valve (SV1) is set to the open state. In the refrigeration / cooling operation, the outdoor expansion valve (39) is set to a fully closed state, the liquid side expansion valve (49) is set to a fully open state, the flow control valve (48), the pressure reducing valve (60), and the first injection. The valve (61), the second injection valve (62), and the internal expansion valve (75) are each adjusted to a predetermined opening degree. In the refrigeration / cooling operation, the outdoor fan (23), the internal fan (73), and the indoor fan (83) are operated.

[First cooling operation]
As shown in FIG. 2, in the refrigeration apparatus (10) during the first cooling operation, both the refrigeration unit (70) and the air conditioning unit (80) are in the thermo-ON state. In the first cooling operation, the third solenoid valve (SV3) is set to an open state, and the indoor expansion valve (85) is adjusted to a predetermined opening. In the refrigerant circuit (11) during the first cooling operation, the outdoor heat exchanger (26) functions as a condenser, the refrigeration heat exchanger (74) functions as an evaporator, and the air conditioning heat exchanger (84). Functions as an evaporator.

The refrigerant compressed by the first compressor (24) and the second compressor (25) passes through the first four-way switching valve (27) and flows through the outdoor heat exchanger (26). In the outdoor heat exchanger (26), the refrigerant dissipates heat to the outdoor air and condenses. The refrigerant condensed in the outdoor heat exchanger (26) passes through the first liquid pipe (41), the liquid receiver (29), and the second liquid pipe (42) in this order. Part of the high-pressure liquid refrigerant in the second liquid pipe (42) flows through the cooling side flow path (52) of the supercooling heat exchanger (51), and the rest flows through the air conditioning side liquid pipe (38).

In the supercooling heat exchanger (51), the high-pressure liquid refrigerant flowing through the cooling side flow path (52) and the intermediate pressure refrigerant flowing through the evaporation side flow path (53) exchange heat. As a result, the high-pressure liquid refrigerant in the cooling side flow path (52) is cooled, and the degree of supercooling is increased. The high-pressure liquid refrigerant cooled by the supercooling heat exchanger (51) flows out to the refrigeration side liquid pipe (37). A part of the liquid refrigerant in the refrigeration side liquid pipe (37) is diverted to the inflow pipe (56) and reduced to the intermediate pressure by the pressure reducing valve (60), and then the evaporation side flow of the supercooling heat exchanger (51) It flows through the road (53). The intermediate pressure refrigerant in the evaporation side channel (53) absorbs heat from the high-pressure liquid refrigerant in the cooling side channel (52) and evaporates. The refrigerant evaporated in the evaporation side flow path (53) is diverted to each introduction pipe (58, 59) via the relay pipe (57), and is sucked into the intermediate pressure part of each compressor (24, 25). The

The refrigerant flowing out from the refrigeration side liquid pipe (37) into the first communication pipe (16) is depressurized by the internal expansion valve (75) and then flows through the refrigeration heat exchanger (74). In the refrigeration heat exchanger (74), the refrigerant absorbs heat from the air in the warehouse and evaporates. As a result, the internal air of the refrigeration unit (70) is cooled. The refrigerant evaporation temperature (eg, −5 ° C.) of the refrigeration heat exchanger (74) is set lower than the refrigerant evaporation temperature (eg, 5 ° C.) of the air conditioning heat exchanger (84) described later. The refrigerant evaporated in the refrigeration heat exchanger (74) sequentially passes through the second communication pipe (17) and the first suction pipe (32), and is sucked into the first compressor (24) and compressed.

The refrigerant flowing out from the second liquid pipe (42) to the air conditioning side liquid pipe (38) passes through the third communication pipe (18) and is depressurized by the indoor expansion valve (85), and then the air conditioning heat exchanger (84). ). In the air conditioning heat exchanger (84), the refrigerant absorbs heat from the room air and evaporates. As a result, the room air is cooled. The refrigerant evaporated in the air conditioning heat exchanger (84) sequentially passes through the fourth connection pipe (19) and the second suction pipe (34), and is sucked into the second compressor (25) and compressed.

[Second cooling operation]
As shown in FIG. 3, in the refrigeration apparatus (10) during the second cooling operation, the refrigeration unit (70) is in the thermo OFF state and the air conditioning unit (80) is in the thermo ON state. In the second cooling operation, the third solenoid valve (SV3) is set to a closed state, and the indoor expansion valve (85) is adjusted to a predetermined opening. In the refrigerant circuit (11) during the second cooling operation, the outdoor heat exchanger (26) functions as a condenser, the refrigeration heat exchanger (74) is deactivated, and the air conditioning heat exchanger (84) is an evaporator. Function as.

Here, the operation of the refrigeration apparatus (10) during the second cooling operation will be described differently from the operation during the first cooling operation. During the second cooling operation, in principle, the first compressor (24) is stopped and the second compressor (25) is operated. However, if the cooling load in the air conditioning unit (80) cannot be handled by the second compressor (25) alone, the flow control valve (48) is opened, and the first compressor (24) and the second compressor ( 25) both work. Further, during the second cooling operation, all of the refrigerant flowing out from the liquid receiver (29) flows into the air conditioning circuit (81) through the air conditioning side liquid pipe (38) and the third connection pipe (18) in this order. To do.

[Third cooling operation]
As shown in FIG. 4, in the refrigeration apparatus (10) during the third cooling operation, the refrigeration unit (70) is in the thermo-ON state, and the air conditioning unit (80) is in the thermo-OFF state. In the third cooling operation, the third solenoid valve (SV3) is set to an open state, and the indoor expansion valve (85) is set to a fully closed state. In the refrigerant circuit (11) during the third cooling operation, the outdoor heat exchanger (26) functions as a condenser, the refrigeration heat exchanger (74) functions as an evaporator, and the air conditioning heat exchanger (84) Pauses.

Here, the difference between the operation of the refrigeration apparatus (10) during the third cooling operation and the operation during the first cooling operation will be described. During the third cooling operation, in principle, the first compressor (24) operates and the second compressor (25) stops. However, if the cooling load in the refrigeration unit (70) cannot be handled by the first compressor (24) alone, the flow control valve (48) is opened, and the first compressor (24) and the second compressor ( 25) both work. Further, during the third cooling operation, all of the refrigerant flowing out from the liquid receiver (29) flows into the cooling side flow path (52) of the supercooling heat exchanger (51), and the cooling side flow path (52) Part of the refrigerant cooled while passing through the refrigerant flows into the refrigeration circuit (71) through the first connection pipe (16).

<Refrigeration / heating operation>
The refrigeration / heating operation is an operation for cooling the interior of the refrigeration unit (70), which is a refrigeration showcase, and heating the room by the air conditioning unit (80). The refrigeration apparatus (10) during the refrigeration / heating operation selectively performs the first concurrent operation, the second concurrent operation, the third concurrent operation, and the heating operation.

[First concurrent operation (heat surplus)]
The first concurrent operation is performed when the cooling load in the refrigeration unit (70) is larger than the heating load in the air conditioning unit (80).

As shown in FIG. 5, in the refrigeration apparatus (10) in the first concurrent operation, both the refrigeration unit (70) and the air conditioning unit (80) are in the thermo-ON state. In the first concurrent operation, the first four-way switching valve (27) is in the second state, the second four-way switching valve (28) is in the second state, the first electromagnetic valve (SV1) is in the open state, and the third electromagnetic valve (SV3) is set to the open state. In the first concurrent operation, the outdoor expansion valve (39), the liquid side expansion valve (49), and the second injection valve (62) are each set to a fully closed state, and the indoor expansion valve (85) is fully opened. The pressure reducing valve (60), the first injection valve (61), and the internal expansion valve (75) are each adjusted to a predetermined opening degree. Further, in the first concurrent operation, the indoor fan (83), the outdoor fan (23), and the internal fan (73) are each in an operating state.

During the first concurrent operation, in principle, the first compressor (24) operates and the second compressor (25) stops. However, if the cooling load in the refrigeration unit (70) cannot be handled by the first compressor (24) alone, the flow control valve (48) is opened, and the first compressor (24) and the second compressor ( 25) both work. Here, the operation of the refrigeration apparatus (10) will be described by taking as an example the case where only the first compressor (24) operates.

In the refrigerant circuit (11) during the first concurrent operation, the outdoor heat exchanger (26) and the air conditioning heat exchanger (84) function as a condenser, and the refrigerated heat exchanger (74) functions as an evaporator. Part of the refrigerant compressed by the first compressor (24) passes through the first four-way switching valve (27) and the fourth connection pipe (19), flows through the air conditioning heat exchanger (84), and the rest It passes through the two-way switching valve (28) and flows through the outdoor heat exchanger (26). In the air conditioning heat exchanger (84), the refrigerant dissipates heat to the room air and condenses. As a result, the room air is heated. The refrigerant condensed in the air conditioning heat exchanger (84) sequentially passes through the third communication pipe (18) and the third liquid pipe (43) and flows through the first liquid pipe (41). In the outdoor heat exchanger (26), the refrigerant dissipates heat to the outdoor air and condenses. The refrigerant radiated by the outdoor heat exchanger (26) flows through the first liquid pipe (41).

The refrigerant merged in the first liquid pipe (41) sequentially passes through the liquid receiver (29) and the second liquid pipe (42), and flows through the cooling side flow path (52) of the supercooling heat exchanger (51). . In the supercooling heat exchanger (51), the high-pressure liquid refrigerant flowing in the cooling side flow path (52) is cooled, while the refrigerant evaporated in the evaporation side flow path (53) is intermediate between the first compressor (24). Inhaled into the pressure section. The refrigerant cooled in the supercooling heat exchanger (51) sequentially passes through the refrigeration side liquid pipe (37) and the first connecting pipe (16), and is depressurized by the internal expansion valve (75). Flow through exchanger (74). In the refrigeration heat exchanger (74), the refrigerant absorbs heat from the air in the warehouse and evaporates. As a result, the internal air of the refrigeration unit (70) is cooled. The refrigerant evaporated in the refrigeration heat exchanger (74) sequentially passes through the second communication pipe (17) and the first suction pipe (32), and is sucked into the first compressor (24) and compressed.

[Second concurrent operation (100% heat recovery)]
The second concurrent operation is performed when the heating load in the air conditioning unit (80) and the cooling load in the refrigeration unit (70) are balanced.

As shown in FIG. 6, in the refrigeration apparatus (10) in the second concurrent operation, both the refrigeration unit (70) and the air conditioning unit (80) are in the thermo-ON state. In the second concurrent operation, the first four-way switching valve (27) is in the second state, the second four-way switching valve (28) is in the first state, the first electromagnetic valve (SV1) is in the closed state, and the third electromagnetic valve (SV3) is set to the open state. In the second concurrent operation, the outdoor expansion valve (39), the liquid side expansion valve (49), and the second injection valve (62) are each set to a fully closed state, and the indoor expansion valve (85) is fully opened. The pressure reducing valve (60), the first injection valve (61), and the internal expansion valve (75) are each adjusted to a predetermined opening degree. In the first operation, the indoor fan (83) and the internal fan (73) are each in an operating state.

During the second concurrent operation, in principle, the first compressor (24) operates and the second compressor (25) stops. However, if the cooling load in the refrigeration unit (70) cannot be handled by the first compressor (24) alone, the flow control valve (48) is opened, and the first compressor (24) and the second compressor ( 25) both work. Here, the operation of the refrigeration apparatus (10) will be described by taking as an example the case where only the first compressor (24) operates.

In the refrigerant circuit (11) during the second concurrent operation, the outdoor heat exchanger (26) is deactivated, the air conditioning heat exchanger (84) functions as a condenser, and the refrigerated heat exchanger (74) functions as an evaporator. To do. The refrigerant compressed by the first compressor (24) sequentially passes through the first four-way switching valve (27) and the fourth connection pipe (19) and flows through the air conditioning heat exchanger (84). In the air conditioning heat exchanger (84), the refrigerant dissipates heat to the room air and condenses. As a result, the room air is heated. The refrigerant condensed in the air conditioning heat exchanger (84) passes through the third communication pipe (18), the third liquid pipe (43), the liquid receiver (29), and the second liquid pipe (42) in this order, and is supercooled. It flows through the cooling side flow path (52) of the heat exchanger (51).

In the supercooling heat exchanger (51), the high-pressure liquid refrigerant flowing in the cooling side flow path (52) is cooled, while the refrigerant evaporated in the evaporation side flow path (53) is intermediate between the first compressor (24). Inhaled into the pressure section. The refrigerant cooled in the supercooling heat exchanger (51) sequentially passes through the refrigeration side liquid pipe (37) and the first connecting pipe (16), and is depressurized by the internal expansion valve (75). Flow through exchanger (74). In the refrigeration heat exchanger (74), the refrigerant absorbs heat from the air in the warehouse and evaporates. As a result, the internal air of the refrigeration unit (70) is cooled. The refrigerant evaporated in the refrigeration heat exchanger (74) sequentially passes through the second communication pipe (17) and the first suction pipe (32), and is sucked into the first compressor (24) and compressed.

[Third concurrent operation (insufficient heat)]
The third concurrent operation is performed when the cooling load in the refrigeration unit (70) is smaller than the heating load in the air conditioning unit (80).

As shown in FIG. 7, in the refrigeration apparatus (10) in the third concurrent operation, both the refrigeration unit (70) and the air conditioning unit (80) are in the thermo-ON state. In the third concurrent operation, the first four-way switching valve (27) is in the second state, the second four-way switching valve (28) is in the first state, the first electromagnetic valve (SV1) is in the closed state, and the third electromagnetic valve (SV3) is set to the open state. In the third concurrent operation, the liquid side expansion valve (49) is set to a fully closed state, the indoor expansion valve (85) is set to a fully open state, the outdoor expansion valve (39), the flow rate adjustment valve (48), The pressure reducing valve (60), the first injection valve (61), the second injection valve (62), and the internal expansion valve (75) are each adjusted to a predetermined opening. Further, in the third concurrent operation, the first compressor (24), the second compressor (25), the indoor fan (83), the outdoor fan (23), and the internal fan (73) are in the operating state.

In the refrigerant circuit (11) in the third concurrent operation, a refrigeration cycle is performed in which the air conditioning heat exchanger (84) serves as a condenser and the outdoor heat exchanger (26) and the refrigerated heat exchanger (74) serve as an evaporator. . The refrigerant compressed by the first compressor (24) and the second compressor (25) passes through the fourth connection pipe (19) and flows through the air conditioning heat exchanger (84). In the air conditioning heat exchanger (84), the refrigerant dissipates heat to the room air and condenses. As a result, the room air is heated. The refrigerant condensed in the air conditioning heat exchanger (84) passes through the third communication pipe (18), the third liquid pipe (43), the liquid receiver (29), and the second liquid pipe (42) in this order, and is supercooled. It flows through the cooling side flow path (52) of the heat exchanger (51).

In the supercooling heat exchanger (51), the high-pressure liquid refrigerant flowing in the cooling side flow path (52) is cooled, while the refrigerant evaporated in the evaporation side flow path (53) 2. Sucked into the intermediate pressure part of the compressor (25). The refrigerant cooled by the supercooling heat exchanger (51) is divided into the refrigeration side liquid pipe (37) and the fourth liquid pipe (44).

The refrigerant that has flowed out to the refrigeration side liquid pipe (37) passes through the first communication pipe (16), is decompressed by the internal expansion valve (75), and then flows through the refrigeration heat exchanger (74). In the refrigeration heat exchanger (74), the refrigerant absorbs heat from the air in the warehouse and evaporates. As a result, the internal air of the refrigeration unit (70) is cooled. The refrigerant evaporated in the refrigeration heat exchanger (74) sequentially passes through the second communication pipe (17) and the first suction pipe (32), and is sucked into the first compressor (24) and compressed.

The refrigerant that has flowed out to the fourth liquid pipe (44) is depressurized by the outdoor expansion valve (39) and then flows through the outdoor heat exchanger (26). In the outdoor heat exchanger (26), the refrigerant absorbs heat from the outdoor air and evaporates. The refrigerant evaporated in the outdoor heat exchanger (26) sequentially passes through the first four-way switching valve (27), the second four-way switching valve (28), and the second suction pipe (34), and the second compressor (25 ) Is inhaled and compressed.

[Heating operation]
As shown in FIG. 8, in the refrigeration apparatus (10) during the heating operation, the refrigeration unit (70) is in the thermo OFF state and the air conditioning unit (80) is in the thermo ON state. This heating operation is performed when the refrigeration unit (70) is in the thermo OFF state during the first concurrent operation, the second concurrent operation, or the third concurrent operation.

During the first concurrent operation, as a rule, the first compressor (24) stops and the second compressor (25) operates. However, if the heating load in the air conditioning unit (80) cannot be handled by the second compressor (25) alone, the flow control valve (48) is opened, and the first compressor (24) and the second compressor ( 25) both work.

Here, the operation of the refrigeration apparatus (10) will be described by taking as an example the case where only the second compressor (25) operates. In addition, here, the operation of the refrigeration apparatus (10) during the heating operation will be described in terms of differences from the operation during the third concurrent operation. During the heating operation, all of the refrigerant flowing out of the liquid receiver (29) flows into the outdoor heat exchanger (26) through the fourth liquid pipe (44). The refrigerant evaporated in the outdoor heat exchanger (26) is sucked into the second compressor (25) as in the third concurrent operation.

-Controller operation-
The controller (120) controls the operation of the refrigeration apparatus (10). Here, the operation performed by the controller (120) during the refrigeration / cooling operation and the operation performed by the controller (120) during the refrigeration / heating operation will be described.

In the controller (120) of this embodiment, the reference capacity of the first compressor section (111) is set to the maximum capacity of the first compressor section (111), and the reference capacity of the second compressor section (112) is set. The capacity is set to the maximum capacity of the second compressor section (112). In the present embodiment, the operating capacity of the first compressor section (111) is the maximum capacity when the operating frequency of the first compressor (24) is the upper limit value, and the operating capacity of the second compressor section (112). Is the maximum capacity when the operating frequency of the second compressor (25) is the upper limit value.

<Operation during refrigeration / cooling operation>
The operation performed by the controller (120) during the refrigeration / cooling operation will be described with reference to the flowcharts of FIGS.

As shown in FIG. 9, in step ST01, the controller (120) determines whether or not the condition that “the refrigeration unit (70) is in the thermo ON state and the air conditioning unit (80) is in the thermo ON state” is satisfied. To do. When this condition is satisfied, the refrigeration apparatus (10) performs the first cooling operation. Therefore, the controller (120) performs the first control operation for the first cooling operation in step ST02. The first control operation performed by the controller (120) during the first cooling operation will be described later.

Here, the controller (120) determines whether or not the air conditioning unit (80) is in the thermo ON state based on the thermo signal received from the air conditioning unit (80). On the other hand, the refrigeration unit (70) may or may not output a thermo signal to the controller (120). When the refrigeration unit (70) outputs a thermo signal, the controller (120) determines whether the refrigeration unit (70) is in the thermo ON state based on the thermo signal received from the refrigeration unit (70). To do. On the other hand, when the refrigeration unit (70) does not output a thermo signal, the controller (120) determines whether or not the refrigeration unit (70) is in the thermo-ON state, the refrigerant pressure LP1 in the first discharge pipe (31). The determination is made based on (that is, the detection value of the first suction pressure sensor (94)). Specifically, the controller (120) indicates that when the pressure LP1 gradually decreases and falls below a predetermined lower limit value (for example, 0.1 MPa), the refrigeration unit (70) switches from the thermo ON state to the thermo OFF state. to decide. Further, when the pressure LP1 gradually increases from less than the lower limit and exceeds a predetermined reference value (for example, 0.48 MPa), it is determined that the refrigeration unit (70) has switched from the thermo OFF state to the thermo ON state.

The refrigeration apparatus (10) may be provided with a plurality of refrigeration units (70) and air conditioning units (80). In this case, the controller (120) satisfies the condition of step ST01 when at least one refrigeration unit (70) is in the thermo-ON state and at least one air-conditioning unit (80) is in the thermo-ON state. Judge.

If the condition of step ST01 is not satisfied, the controller (120) determines whether or not the condition that “the refrigeration unit (70) is in the thermo OFF state and the air conditioning unit (80) is in the thermo ON state” is satisfied in step ST03. Judging. When this condition is satisfied, the refrigeration apparatus (10) performs the second cooling operation. Therefore, when this condition is satisfied, the controller (120) performs the control operation for the second cooling operation.

The refrigeration apparatus (10) may be provided with a plurality of refrigeration units (70) and air conditioning units (80). In this case, the controller (120) determines that the condition of step ST03 is satisfied when all the refrigeration units (70) are in the thermo OFF state and at least one air conditioning unit (80) is in the thermo ON state. to decide.

The control operation performed by the controller (120) during the second cooling operation will be described. As described above, during the second cooling operation, in principle, the first compressor section (111) constituted by the first compressor (24) is stopped and constituted by the second compressor (25). The second compressor section (112) is activated. Therefore, in step ST04, the controller (120) determines the operating capacity of the second compressor section (112) (that is, the operating frequency of the second compressor (25)) as the refrigerant in the second suction pipe (34). The pressure LP2 (that is, the detection value of the second suction pressure sensor (96)) is adjusted to be the second target low pressure (0.85 MPa in this embodiment). Specifically, the controller (120) increases the operation capacity of the second compressor section (112) when the pressure LP2 is higher than the second target low pressure (that is, the operation of the second compressor (25)). When the pressure LP2 is lower than the second target low pressure, the operating capacity of the second compressor section (112) is decreased (that is, the operating frequency of the second compressor (25) is decreased). .

In the next step ST05, the controller (120) determines whether or not the condition that “the operating capacity of the second compressor section (112) is the maximum capacity” is met. When this condition is satisfied, the cooling load of the air conditioning unit (80) cannot be processed by the second compressor unit (112) alone. Therefore, the controller (120) performs the second control operation in step ST06. This second control operation will be described later. On the other hand, when this condition is not satisfied, the cooling load of the air conditioning unit (80) can be processed only by the second compressor unit (112). Therefore, in step ST07, the controller (120) fully closes the flow rate adjustment valve (48) and adjusts the operating capacity of the second compressor unit (112) based on the pressure LP2.

If the condition of step ST03 is not satisfied, the controller (120) determines whether or not the condition that “the refrigeration unit (70) is in the thermo-ON state and the air conditioning unit (80) is in the thermo-OFF state” in step ST08. Judging. When this condition is satisfied, the refrigeration apparatus (10) performs the third cooling operation. Therefore, when this condition is satisfied, the controller (120) performs the control operation for the third cooling operation.

The refrigeration apparatus (10) may be provided with a plurality of refrigeration units (70) and air conditioning units (80). In this case, the controller (120) determines that the condition of step ST08 is satisfied when at least one refrigeration unit (70) is in the thermo-ON state and all the air-conditioning units (80) are in the thermo-OFF state. to decide.

The control operation performed by the controller (120) during the third cooling operation will be described. As described above, during the third cooling operation, in principle, the first compressor (24) operates and the second compressor (25) stops. Therefore, in step ST09, the controller (120) determines the operating capacity of the first compressor unit (111) (that is, the operating frequency of the first compressor (24)) as the refrigerant in the first suction pipe (32). The pressure LP1 is adjusted to be the first target low pressure (0.48 MPa in this embodiment). Specifically, the controller (120) increases the operating capacity of the first compressor unit (111) when the pressure LP1 is higher than the first target low pressure (that is, the operation of the first compressor (24)). When the pressure LP1 is lower than the first target low pressure, the operating capacity of the first compressor unit (111) is decreased (that is, the operating frequency of the first compressor (24) is decreased). .

In the next step ST10, the controller (120) determines whether or not the condition that “the operating capacity of the first compressor section (111) is the maximum capacity” is met. When this condition is satisfied, the cooling load of the refrigeration unit (70) cannot be processed by the first compressor unit (111) alone.

Therefore, when the condition of step ST10 is satisfied, the controller (120) determines the operating capacity of the second compressor section (112) (that is, the operating frequency of the second compressor (25)) in step ST11. The refrigerant pressure LP1 in the one suction pipe (32) is adjusted to be the first target low pressure (0.48 MPa). That is, the controller (120) adjusts the operating capacities of the first compressor unit (111) and the second compressor unit (112) so that the pressure LP1 becomes the first target low pressure. However, in step ST11, the operating capacity of the first compressor section (111) reaches the maximum capacity. Therefore, in step ST11, the controller (120) keeps the operating capacity of the first compressor unit (111) at the maximum capacity, and the operating capacity of the second compressor unit (112) is set to the first target low pressure. Adjust so that In the next step ST12, the controller (120) fully opens the flow rate adjustment valve (48).

When the controller (120) performs the operations of step ST11 and step ST12, a part of the refrigerant evaporated in the refrigeration heat exchanger (74) is sucked into the second compressor section (112), and the rest is the first. It is sucked into the compressor section (111). Therefore, in this state, the cooling load of the refrigeration unit (70) is processed by both the first compressor unit (111) and the second compressor unit (112). For this reason, even in a situation where the cooling load of the refrigeration unit (70) cannot be processed by the first compressor unit (111) alone, the internal temperature of the refrigeration unit (70) can be kept at the set temperature.

On the other hand, when the condition of step ST10 is not satisfied, the cooling load of the refrigeration unit (70) can be processed only by the first compressor unit (111). Therefore, in step ST13, the controller (120) fully closes the flow rate control valve (48), and the operating capacity of the first compressor section (111) is set to the refrigerant pressure LP1 in the first suction pipe (32). The first target low pressure (0.48 MPa) is adjusted.

If the condition of step ST08 is not satisfied, both the refrigeration unit (70) and the air conditioning unit (80) are in the thermo OFF state. Therefore, in this case, the controller (120) fully closes the flow rate adjustment valve (48) in step ST14, and stops the first compressor unit (111) and the second compressor unit (112) in step ST15. . That is, in step ST15, the controller (120) stops both the first compressor (24) and the second compressor (25).

[First control operation]
As described above, the controller (120) performs the first control operation during the first cooling operation. Here, the first control operation will be described with reference to FIG.

The first control operation is performed when both the refrigeration unit (70) and the air conditioning unit (80) are in the thermo-ON state (see FIG. 9). That is, the first control operation is performed in a state where both the first compressor unit (111) and the second compressor unit (112) are operating.

In step ST21, the controller (120) determines whether or not the condition that “the operating capacity of the second compressor section (112) is the maximum capacity” is met. When this condition is not satisfied, the cooling load of the air conditioning unit (80) can be processed only by the second compressor unit (112). Therefore, when the condition of step ST21 is not satisfied, the controller (120) fully closes the flow rate control valve (48) in step ST26, and in step ST27, the first compressor section (111) and the second compressor section. Adjust the operating capacity of (112). When the flow control valve (48) is in a fully closed state, the first compressor (24) sucks only the refrigerant evaporated in the refrigeration heat exchanger (74), and the second compressor (25) is an air conditioning heat exchanger. Only the refrigerant that has evaporated in (84) is sucked.

In step ST27, the controller (120) sets the operating capacity of the first compressor section (111) so that the refrigerant pressure LP1 in the first suction pipe (32) becomes the first target low pressure (0.48 MPa). Adjust. That is, the controller (120) increases the operating capacity of the first compressor unit (111) when the pressure LP1 is higher than the first target low pressure, and when the pressure LP1 is lower than the first target low pressure, The operating capacity of the first compressor section (111) is reduced.

In Step ST27, the controller (120) sets the operating capacity of the second compressor section (112), and the refrigerant pressure LP2 in the second suction pipe (34) becomes the second target low pressure (0.85 MPa). Adjust as follows. That is, the controller (120) increases the operating capacity of the second compressor section (112) when the pressure LP2 is higher than the second target low pressure, and when the pressure LP2 is lower than the second target low pressure, The operating capacity of the second compressor section (112) is reduced.

When the condition of step ST21 is satisfied, the controller (120) determines whether or not the condition that “the operating capacity of the first compressor unit (111) is the maximum capacity” is satisfied in step ST22.

When the condition of step ST22 is not satisfied, the operating capacity of the second compressor section (112) is the maximum capacity, but the operating capacity of the first compressor section (111) has not reached the maximum capacity. That is, when this condition is not satisfied, the cooling load of the refrigeration unit (70) can be processed only by the first compressor unit (111), but the cooling load of the air conditioning unit (80) is processed by the second compressor unit (112). It is a situation that can not be processed only by.

Therefore, when the condition of step ST22 is not satisfied, the controller (120) determines the opening degree of the flow control valve (48) and the refrigerant pressure LP1 in the first suction pipe (32) as the first target low pressure in step ST24. Adjust to (0.48 MPa). In the next step ST25, the controller (120) sets the operating capacity of the first compressor section (111) so that the refrigerant pressure LP2 in the second suction pipe (34) is the second target low pressure (0.85 MPa). Adjust so that

When the flow control valve (48) is open in a situation where both the first compressor part (111) and the second compressor part (112) are operating, the refrigerant flowing through the second suction pipe (34) (that is, Part of the refrigerant evaporated in the air conditioning heat exchanger (84) is sucked into the first compressor (24) through the connecting pipe (47) and the rest is sucked into the second compressor (25). Is done. That is, in this case, the first compressor (24) sucks all of the refrigerant evaporated in the refrigeration heat exchanger (74) and part of the refrigerant evaporated in the air conditioning heat exchanger (84), while the second compression The machine (25) sucks in the refrigerant not evaporated into the connection pipe (47) from the refrigerant evaporated in the air conditioning heat exchanger (84). Therefore, in this case, the cooling load of the refrigeration unit (70) is processed by the first compressor unit (111), and the cooling load of the air conditioning unit (80) is changed to the first compressor unit (111) and the second compressor unit. (112) is processed by both.

The operation of the controller (120) in step ST24 will be described in detail. When the refrigerant pressure LP1 in the first suction pipe (32) exceeds the first target low pressure (0.48 MPa), the controller (120) reduces the opening degree of the flow control valve (48). When the opening degree of the flow rate control valve (48) becomes small, the flow rate of the refrigerant flowing from the connection pipe (47) into the first suction pipe (32) decreases, and the pressure LP1 decreases. On the other hand, when the pressure LP1 is lower than the first target low pressure, the controller (120) increases the opening degree of the flow control valve (48). When the opening degree of the flow control valve (48) increases, the flow rate of the refrigerant flowing from the connection pipe (47) into the first suction pipe (32) increases, and the pressure LP1 increases.

The operation of the controller (120) in step ST25 will be described in detail. When the refrigerant pressure LP2 in the second suction pipe (34) exceeds the second target low pressure (0.85 MPa), the controller (120) increases the operating capacity of the first compressor unit (111) (that is, The operating frequency of the first compressor (24) is increased). When the operating capacity of the first compressor section (111) increases, the flow rate of the refrigerant flowing from the second suction pipe (34) into the connection pipe (47) increases, and the pressure LP2 decreases. On the other hand, when the pressure LP2 is lower than the second target low pressure, the controller (120) decreases the operating capacity of the first compressor unit (111) (that is, decreases the operating frequency of the first compressor (24)). ) When the operating capacity of the first compressor section (111) decreases, the flow rate of the refrigerant flowing from the second suction pipe (34) into the connection pipe (47) decreases, and the pressure LP2 increases.

When the condition of step ST22 is satisfied, the operating capacity of the first compressor section (111) is the maximum capacity, and the operating capacity of the second compressor section (112) is also the maximum capacity. That is, when this condition is satisfied, the operating capacities of the first compressor unit (111) and the second compressor unit (112) cannot be increased. Therefore, when the condition of step ST22 is satisfied, the controller (120) determines the opening degree of the flow rate adjustment valve (48) and the refrigerant pressure LP1 in the first suction pipe (32) as the first target low pressure in step ST23. Adjust to (0.48 MPa).

When the flow control valve (48) is open in a situation where the operating capacities of the first compressor part (111) and the second compressor part (112) are the maximum capacity, the refrigerant flowing through the second suction pipe (34) ( That is, a part of the refrigerant evaporated in the air conditioning heat exchanger (84) is sucked into the first compressor (24) through the connection pipe (47), and the rest is sent to the second compressor (25). Inhaled. That is, in this case, the first compressor (24) sucks all of the refrigerant evaporated in the refrigeration heat exchanger (74) and part of the refrigerant evaporated in the air conditioning heat exchanger (84). In this case, when the pressure LP1 exceeds the first target low pressure, the controller (120) reduces the opening degree of the flow control valve (48). When the opening degree of the flow rate control valve (48) becomes small, the flow rate of the refrigerant flowing from the connection pipe (47) into the first suction pipe (32) decreases, and thus the pressure LP1 decreases. On the other hand, when the pressure LP1 falls below the first target low pressure in this case, the controller (120) increases the opening degree of the flow rate control valve (48). When the opening degree of the flow rate control valve (48) increases, the flow rate of the refrigerant flowing from the connection pipe (47) into the first suction pipe (32) increases, and thus the pressure LP1 increases.

[Second control operation]
As described above, the controller (120) performs the second control operation when the condition of step ST05 in FIG. 9 is satisfied during the second cooling operation. Here, the second control operation will be described with reference to FIG.

In the second control operation, the refrigeration unit (70) is in the thermo OFF state and the air conditioning unit (80) is in the thermo ON state, and the operation capacity of the second compressor unit (112) has already reached the maximum capacity. (See FIG. 9).

In step ST31, the controller (120) determines whether the refrigeration unit (70) outputs a thermo signal or does not output a thermo signal. When the refrigeration unit (70) outputs a thermo signal, the controller (120) determines whether the refrigeration unit (70) is in a thermo-ON state based on the thermo signal received from the refrigeration unit (70). It can be determined whether the state is OFF. Accordingly, when the refrigeration unit (70) outputs a thermo signal indicating that the thermo is OFF, the refrigerant pressure LP1 in the first suction pipe (32) exceeds the first target low pressure (0.48 MPa). It does not matter. Therefore, the controller (120) fully opens the flow control valve (48) in step ST32. In step ST33, the controller (120) sets the operating capacity of the first compressor section (111), and the refrigerant pressure LP2 in the second suction pipe (34) becomes the second target low pressure (0.85 MPa). Adjust as follows.

When the flow control valve (48) is fully open, the refrigerant pressure LP1 in the first suction pipe (32) becomes substantially equal to the refrigerant pressure LP2 in the second suction pipe (34). In step ST33, the controller (120) maintains the maximum operating capacity of the second compressor section (112), while the pressure LP2 is the second operating capacity of the first compressor section (111). The target low pressure (0.85 MPa) is adjusted. In this state, a part of the refrigerant evaporated in the air conditioning heat exchanger (84) is sucked into the first compressor (24) through the connection pipe (47), and the remaining is the second compressor (25). Inhaled.

On the other hand, when the refrigeration unit (70) does not output a thermo signal, the controller (120) indicates that the refrigeration unit (70) has been switched from the thermo OFF state to the thermo ON state in the first suction pipe ( 32) Judgment must be made based on the refrigerant pressure LP1. For this purpose, the controller (120) needs to perform an operation for keeping the pressure LP1 at the first target low pressure regardless of whether the refrigeration unit (70) is in the thermo-ON state or the thermo-OFF state. Therefore, in this case, the controller (120) performs the operations of steps ST34 to ST37.

When the refrigeration unit (70) does not output a thermo signal, the controller (120) determines whether or not the condition that “the operating capacity of the first compressor unit (111) is the maximum capacity” is satisfied in step ST34. to decide.

When the condition of step ST34 is not satisfied, the operating capacity of the second compressor section (112) is the maximum capacity, but the operating capacity of the first compressor section (111) has not reached the maximum capacity. That is, when this condition is not satisfied, the cooling load of the refrigeration unit (70) can be processed only by the first compressor unit (111), but the cooling load of the air conditioning unit (80) is processed by the second compressor unit (112). It is a situation that can not be processed only by.

Therefore, when the condition of step ST34 is not satisfied, the controller (120) determines the opening degree of the flow rate control valve (48) and the refrigerant pressure LP1 in the first suction pipe (32) as the first target low pressure in step ST36. Adjust to (0.48 MPa). The operation of the controller (120) in step ST36 is the same as the operation of the controller (120) in step ST24 of FIG. In the next step ST37, the controller (120) sets the operating capacity of the first compressor section (111) so that the refrigerant pressure LP2 in the second suction pipe (34) is the second target low pressure (0.85 MPa). Adjust so that The operation of the controller (120) in step ST37 is the same as the operation of the controller (120) in step ST25 of FIG. When the controller (120) performs the operations of step ST36 and step ST37, the cooling load of the refrigeration unit (70) is processed by the first compressor unit (111), and the cooling load of the air conditioning unit (80) is the first. Processed by both the first compressor section (111) and the second compressor section (112).

When the condition of step ST34 is satisfied, the operating capacity of the first compressor section (111) is the maximum capacity, and the operating capacity of the second compressor section (112) is also the maximum capacity. That is, when this condition is satisfied, the operating capacities of the first compressor unit (111) and the second compressor unit (112) cannot be increased. Therefore, when the condition of step ST34 is satisfied, the controller (120) determines the opening degree of the flow rate control valve (48) and the refrigerant pressure LP1 in the first suction pipe (32) as the first target low pressure in step ST35. Adjust to (0.48 MPa). The operation of the controller (120) in step ST35 is the same as the operation of the controller (120) in step ST23 of FIG.

<Operation during refrigeration / heating operation>
The operation performed by the controller (120) during the refrigeration / heating operation will be described with reference to the flowcharts of FIGS.

As shown in FIG. 12, in step ST41, the controller (120) reads that “the air conditioning unit (80) is in the thermo-ON state and the refrigerant condensation temperature Tc in the air conditioning heat exchanger (84) is less than 60 ° C. The success or failure of the condition “Yes” is determined.

Note that the refrigeration apparatus (10) may be provided with a plurality of air conditioning units (80). In this case, the controller (120) determines that the condition of step ST41 is satisfied when the at least one air conditioning unit (80) is in the thermo-ON state and the refrigerant condensation temperature Tc is less than 60 ° C. . The controller (120) calculates the saturation temperature of the refrigerant corresponding to the detection value of the discharge pressure sensor (91), and sets the value as the refrigerant condensation temperature Tc in the air conditioning heat exchanger (84).

When the condition of step ST41 is not satisfied, the controller (120) performs the control operation for the first concurrent operation in step ST42. This control operation will be described later. On the other hand, when the condition of step ST41 is satisfied, the controller (120) determines whether or not the condition that “the refrigerant condensing temperature Tc in the air conditioning heat exchanger (84) is less than 55 ° C.” is satisfied in step ST43. . When the condition of step ST43 is not satisfied, the controller (120) performs the control operation for the second concurrent operation in step ST44. This control operation will be described later. On the other hand, when the condition of step ST43 is satisfied, the controller (120) performs the operation of step ST45.

In step ST45, the controller (120) determines whether or not the condition that “the refrigeration unit (70) is in the thermo ON state” is satisfied. The refrigeration apparatus (10) may be provided with a plurality of refrigeration units (70). In this case, the controller (120) determines that the condition of step ST45 is satisfied when at least one refrigeration unit (70) is in the thermo-ON state.

When the condition of step ST45 is satisfied, the refrigeration apparatus (10) is performing the third coexistence operation (see FIG. 7). As described above, both the first compressor unit (111) and the second compressor unit (112) operate during the third concurrent operation. When the condition of step ST45 is satisfied, the controller (120) determines whether or not the condition that “the operating capacity of the first compressor unit (111) is the maximum capacity” is satisfied in step ST46.

If the condition of step ST46 is not satisfied, the cooling load of the refrigeration unit (70) can be handled only by the first compressor unit (111). Therefore, if the condition of step ST46 is not satisfied, the controller (120) determines the operating capacity of the first compressor unit (111) (that is, the operating frequency of the first compressor (24)) in step ST49. The refrigerant pressure LP1 in the one suction pipe (32) is adjusted to be a target low pressure (0.48 MPa in the present embodiment). In the next step ST50, the controller (120) fully closes the flow rate adjustment valve (48). In the next step ST51, the controller (120) determines the operating capacity of the second compressor section (112) (that is, the operating frequency of the second compressor (25)) in the air conditioning heat exchanger (84). It adjusts so that the condensation temperature Tc of a refrigerant | coolant may become target temperature (this embodiment 55 degreeC).

When the operation of step ST51 is completed, the flow rate control valve (48) is fully closed. Therefore, the first compressor (24) sucks only the refrigerant evaporated in the refrigeration heat exchanger (74), and the second compressor (25) receives only the refrigerant evaporated in the outdoor heat exchanger (26). Inhale (see Figure 7).

The operation of the controller (120) in step ST49 will be described in detail. When the refrigerant pressure LP1 in the first suction pipe (32) is higher than the target low pressure (0.48 MPa), the controller (120) controls the first compressor section (111) to reduce the pressure LP1. Increase operating capacity. On the other hand, when the pressure LP1 is lower than the first target low pressure (0.48 MPa), the controller (120) decreases the operating capacity of the first compressor unit (111) in order to increase the pressure LP1.

The operation of the controller (120) in step ST51 will be described in detail. When the condensation temperature Tc of the refrigerant in the air conditioning heat exchanger (84) exceeds the target temperature (55 ° C.), the controller (120) decreases the operating capacity of the second compressor unit (112). When the operating capacity of the second compressor section (112) decreases, the refrigerant pressure in the first discharge pipe (31) and the second discharge pipe (33) decreases, and the refrigerant condensing temperature Tc decreases. On the other hand, when the condensation temperature Tc of the refrigerant in the air conditioning heat exchanger (84) is lower than the target temperature (55 ° C.), the controller (120) increases the operating capacity of the second compressor section (112). When the operating capacity of the second compressor section (112) increases, the refrigerant pressure in the first discharge pipe (31) and the second discharge pipe (33) increases, and the refrigerant condensing temperature Tc increases.

On the other hand, when the condition of step ST46 is established, the cooling load of the refrigeration unit (70) cannot be processed by the first compressor unit (111) alone. Therefore, in this case, in step ST47, the controller (120) sets the operating capacity of the second compressor section (112) so that the refrigerant pressure LP1 in the first suction pipe (32) is the target low pressure (0.48 MPa). Adjust so that In the next step ST48, the controller (120) fully opens the flow rate adjustment valve (48). In this case, when the flow control valve (48) is fully opened, a part of the refrigerant flowing through the first suction pipe (32) flows into the second suction pipe (34) through the connection pipe (47). That is, a part of the refrigerant evaporated in the refrigeration heat exchanger (74) is sucked into the second compressor (25), and the rest is sucked into the first compressor (24).

The operation of the controller (120) in step ST47 will be described in detail. When the refrigerant pressure LP1 in the first suction pipe (32) exceeds the target low pressure (0.48 MPa), the controller (120) increases the operating capacity of the second compressor unit (112). When the operating capacity of the second compressor section (112) increases, the flow rate of the refrigerant sucked into the second compressor (25) from the first suction pipe (32) through the connection pipe (47) increases. The pressure LP1 decreases. On the other hand, when the pressure LP1 is lower than the target low pressure, the controller (120) decreases the operating capacity of the second compressor section (112). When the operating capacity of the second compressor section (112) decreases, the flow rate of the refrigerant sucked into the second compressor (25) from the first suction pipe (32) through the connection pipe (47) decreases, The pressure LP1 increases.

When the controller (120) performs the operation of step ST47, the refrigerant pressure LP1 in the first suction pipe (32) (that is, the refrigerant evaporation pressure in the refrigeration heat exchanger (74)) is maintained at the target low pressure. When the controller (120) performs the operation of step ST48, the refrigerant condensing temperature Tc in the air-conditioning heat exchanger (84) becomes a result.

When the controller (120) performs the operations of step ST47 and step ST48, a part of the refrigerant evaporated in the refrigeration heat exchanger (74) is sucked into the second compressor section (112), and the rest is the first. It is sucked into the compressor section (111). Therefore, in this state, the cooling load of the refrigeration unit (70) is processed by both the first compressor unit (111) and the second compressor unit (112). For this reason, even in a situation where the cooling load of the refrigeration unit (70) cannot be processed by the first compressor unit (111) alone, the internal temperature of the refrigeration unit (70) can be kept at the set temperature.

If the condition of step ST45 is not satisfied, the refrigeration apparatus (10) is performing the heating operation (see FIG. 8). As described above, during the heating operation, in principle, the first compressor unit (111) is stopped and the second compressor unit (112) is operated. In this case, in step ST52, the controller (120) determines whether or not the condition that “the operating capacity of the second compressor section (112) is the maximum capacity” is met.

If the condition of step ST52 is not satisfied, the heating load of the air conditioning unit (80) can be processed only by the second compressor section (112). Therefore, if the condition of step ST52 is not satisfied, the controller (120) sets the operating capacity of the second compressor section (112) and the refrigerant condensing temperature Tc in the air conditioning heat exchanger (84) as the target in step ST55. Adjust to a temperature (55 ° C). The operation performed by the controller (120) in step ST55 is the same as the operation performed by the controller (120) in step ST51. In the next step ST56, the controller (120) fully closes the flow rate adjustment valve (48).

When the condition of step ST52 is satisfied, the heating load of the air conditioning unit (80) cannot be processed by the second compressor unit (112) alone. Therefore, in this case, in step ST53, the controller (120) sets the operating capacity of the first compressor unit (111) to the refrigerant condensation temperature Tc in the air conditioning heat exchanger (84) as the target temperature (55 ° C.). Adjust so that In the next step ST54, the controller (120) fully opens the flow control valve (48). In this case, when the flow rate adjustment valve (48) is fully opened, a part of the refrigerant flowing through the second suction pipe (34) flows into the first suction pipe (32) through the connection pipe (47). That is, a part of the refrigerant evaporated in the outdoor heat exchanger (26) is sucked into the first compressor (24) and the rest is sucked into the second compressor (25). The controller (120) performs the operation of step ST53, whereby the refrigerant condensing temperature Tc in the air conditioning heat exchanger (84) is maintained at the target temperature (55 ° C.).

The operation of the controller (120) in step ST53 will be described in detail. When the refrigerant condensing temperature Tc in the air conditioning heat exchanger (84) exceeds the target temperature (55 ° C.), the controller (120) decreases the operating capacity of the first compressor unit (111). When the operating capacity of the first compressor section (111) decreases, the refrigerant pressure in the first discharge pipe (31) and the second discharge pipe (33) decreases, and the refrigerant condensing temperature Tc decreases. On the other hand, when the refrigerant condensing temperature Tc in the air conditioning heat exchanger (84) is lower than the target temperature (55 ° C.), the controller (120) increases the operating capacity of the first compressor section (111). When the operating capacity of the first compressor section (111) increases, the refrigerant pressure in the first discharge pipe (31) and the second discharge pipe (33) increases, and the refrigerant condensation temperature Tc increases.

When the controller (120) performs the operations of step ST53 and step ST54, a part of the refrigerant evaporated in the outdoor heat exchanger (26) is sucked into the first compressor section (111), and the rest is the second. It is sucked into the compressor section (112). Therefore, in this state, the heating load of the air conditioning unit (80) is processed by both the first compressor unit (111) and the second compressor unit (112). For this reason, even in a situation where the heating load of the air conditioning unit (80) cannot be processed by the second compressor unit (112) alone, the temperature of the room in which the air conditioning unit (80) is installed can be kept at the set temperature. .

[Control action for the first concurrent operation]
A control operation performed by the controller (120) when the refrigeration apparatus (10) performs the first concurrent operation will be described with reference to FIG.

As described above, in the refrigeration apparatus (10) in the first concurrent operation, both the refrigeration unit (70) and the air conditioning unit (80) are in the thermo-ON state, and the first compressor unit (111) and the second compressor Both parts (112) are activated (see FIG. 5).

In step ST61, the controller (120) determines whether or not a condition that “the refrigeration unit (70) is in the thermo ON state” is satisfied. The refrigeration apparatus (10) may be provided with a plurality of refrigeration units (70). In this case, the controller (120) determines that the condition of step ST61 is satisfied when at least one refrigeration unit (70) is in the thermo-ON state.

When the condition of step ST61 is satisfied, the controller (120) determines whether or not the condition that “the operating capacity of the first compressor unit (111) is the maximum capacity” is satisfied in step ST62.

If the condition of step ST62 is not satisfied, the cooling load of the refrigeration unit (70) can be handled only by the first compressor unit (111). Therefore, if the condition of step ST62 is not satisfied, the controller (120) determines that the operating capacity of the first compressor section (111) is the target low pressure in step ST65 and the refrigerant pressure LP1 in the first suction pipe (32) is the target low pressure. Adjust to (0.48 MPa). The operation performed by the controller (120) in step ST65 is the same as the operation performed by the controller (120) in step ST49 of FIG. In the next step ST66, the controller (120) sets the flow rate adjustment valve (48) to either the fully closed state or the fully closed state. When the controller (120) performs the operation of step ST66, the second four-way switching valve (28) is in the first state (see FIG. 5). Accordingly, in this case, the flow rate control valve (48) may be in a fully closed state or a fully closed state.

On the other hand, when the condition of step ST62 is satisfied, the cooling load of the refrigeration unit (70) cannot be processed by the first compressor unit (111) alone. Therefore, in this case, in step ST63, the controller (120) sets the operating capacity of the second compressor section (112) so that the refrigerant pressure LP1 in the first suction pipe (32) is the target low pressure (0.48 MPa). Adjust so that In the next step ST64, the controller (120) fully opens the flow control valve (48). In this case, when the flow control valve (48) is fully opened, a part of the refrigerant flowing through the first suction pipe (32) flows into the second suction pipe (34) through the connection pipe (47). That is, a part of the refrigerant evaporated in the refrigeration heat exchanger (74) is sucked into the second compressor (25), and the rest is sucked into the first compressor (24). The operation in step ST63 is the same as the operation in step ST47 in FIG.

When the controller (120) performs the operation of step ST63, the refrigerant pressure LP1 (that is, the refrigerant evaporation pressure in the refrigeration heat exchanger (74)) in the first suction pipe (32) is maintained at the target low pressure. When the controller (120) performs the operation of step ST64, the refrigerant condensing temperature Tc in the air-conditioning heat exchanger (84) becomes a result.

When the controller (120) performs the operations of step ST63 and step ST64, a part of the refrigerant evaporated in the refrigeration heat exchanger (74) is sucked into the second compressor section (112) and the rest is the first. It is sucked into the compressor section (111). Therefore, in this state, the cooling load of the refrigeration unit (70) is processed by both the first compressor unit (111) and the second compressor unit (112). For this reason, even in a situation where the cooling load of the refrigeration unit (70) cannot be processed by the first compressor unit (111) alone, the internal temperature of the refrigeration unit (70) can be kept at the set temperature.

If the condition of step ST61 is not satisfied, the refrigeration unit (70) is in the thermo OFF state. If the refrigeration unit (70) is in the thermo-off state during the first concurrent operation, there is no heat exchanger functioning as an evaporator, and thus the operation of the refrigeration apparatus (10) cannot be continued. Therefore, when the condition of step ST61 is not satisfied, the controller (120) causes the flow rate adjustment valve (48) to be fully closed in step ST67. Further, in the next step ST68, the controller (120) switches the operation of the refrigeration apparatus (10) from the first coexistence operation to the heating operation (see FIG. 8), and continues heating the room by the air conditioning unit (80). Let

[Control action for second concurrent operation]
A control operation performed by the controller (120) when the refrigeration apparatus (10) is performing the second concurrent operation will be described with reference to FIG.

As described above, in the refrigeration apparatus (10) in the second concurrent operation, both the refrigeration unit (70) and the air conditioning unit (80) are in the thermo-ON state. Further, during the second concurrent operation, as a rule, the first compressor section (111) operates and the second compressor section (112) stops (see FIG. 6).

In step ST71, the controller (120) determines whether or not the condition that “the refrigeration unit (70) is in the thermo ON state” is satisfied. The refrigeration apparatus (10) may be provided with a plurality of refrigeration units (70). In this case, the controller (120) determines that the condition of step ST71 is satisfied when at least one refrigeration unit (70) is in the thermo-ON state.

When the condition of step ST71 is satisfied, the controller (120) determines whether or not the condition that “the operating capacity of the first compressor unit (111) is the maximum capacity” is satisfied in step ST72.

If the condition of step ST72 is not satisfied, the cooling load of the refrigeration unit (70) can be handled only by the first compressor unit (111). Therefore, if the condition of step ST72 is not satisfied, the controller (120) determines that the operating capacity of the first compressor unit (111) is the target low pressure in step ST75 and the refrigerant pressure LP1 in the first suction pipe (32) is the target low pressure. Adjust to (0.48 MPa). The operation performed by the controller (120) in step ST75 is the same as the operation performed by the controller (120) in step ST49 of FIG. In the next step ST76, the controller (120) fully closes the flow control valve (48).

On the other hand, when the condition of step ST72 is satisfied, the cooling load of the refrigeration unit (70) cannot be processed by the first compressor unit (111) alone. Therefore, in this case, in step ST73, the controller (120) sets the operating capacity of the second compressor section (112) so that the refrigerant pressure LP1 in the first suction pipe (32) is the target low pressure (0.48 MPa). Adjust so that In the next step ST74, the controller (120) fully opens the flow rate adjustment valve (48). In this case, when the flow control valve (48) is fully opened, a part of the refrigerant flowing through the first suction pipe (32) flows into the second suction pipe (34) through the connection pipe (47). That is, a part of the refrigerant evaporated in the refrigeration heat exchanger (74) is sucked into the second compressor (25), and the rest is sucked into the first compressor (24). The operation in step ST73 is the same as the operation in step ST47 in FIG.

When the controller (120) performs the operation of step ST73, the refrigerant pressure LP1 in the first suction pipe (32) (that is, the refrigerant evaporation pressure in the refrigeration heat exchanger (74)) is maintained at the target low pressure. When the controller (120) performs the operation of step ST74, the refrigerant condensing temperature Tc in the air-conditioning heat exchanger (84) becomes a consequence.

When the controller (120) performs the operations of step ST73 and step ST74, a part of the refrigerant evaporated in the refrigeration heat exchanger (74) is sucked into the second compressor section (112), and the rest is the first. It is sucked into the compressor section (111). Therefore, in this state, the cooling load of the refrigeration unit (70) is processed by both the first compressor unit (111) and the second compressor unit (112). For this reason, even in a situation where the cooling load of the refrigeration unit (70) cannot be processed by the first compressor unit (111) alone, the internal temperature of the refrigeration unit (70) can be kept at the set temperature.

If the condition of step ST71 is not satisfied, the refrigeration unit (70) is in the thermo OFF state. If the refrigeration unit (70) is in the thermo-off state during the first concurrent operation, there is no heat exchanger functioning as an evaporator, and thus the operation of the refrigeration apparatus (10) cannot be continued. Therefore, when the condition of step ST71 is not satisfied, the controller (120) causes the flow rate adjustment valve (48) to be fully closed in step ST67. In step ST78, the controller (120) switches the operation of the refrigeration apparatus (10) from the first coexistence operation to the heating operation (see FIG. 8), and continues heating the room by the air conditioning unit (80). Let

-Effect of Embodiment 1-
In the refrigeration apparatus (10) of the present embodiment, a connection pipe (47) connecting the first suction pipe (32) and the second suction pipe (34) is provided in the refrigerant circuit (11), and the flow rate is variable. A control valve (48) is provided in the connection pipe (47).

First, the refrigeration apparatus (10) of the present embodiment is a refrigerant necessary for processing the cooling load of the refrigeration unit (70) (specifically, keeping the internal temperature of the refrigeration unit (70) at a set temperature). When the flow rate of the refrigerant exceeds the flow rate of the refrigerant that can be sucked into the first compressor unit (111) from the refrigeration heat exchanger (74), the refrigerant flowing through the first suction pipe (32) is transferred to the first compressor unit (111). And the second compressor section (112).

When the refrigerant flowing through the first suction pipe (32) is sucked into both the first compressor part (111) and the second compressor part (112), the opening degree of the flow control valve (48) is changed. Thus, the flow rate of the refrigerant sucked into the second compressor section (112) through the connection pipe (47) can be adjusted. In this case, the flow rate of the refrigerant flowing through the refrigeration heat exchanger (74) is adjusted to an appropriate value according to the cooling load of the refrigeration unit (70) by adjusting the opening of the flow rate control valve (48). It becomes possible to set.

Next, the refrigeration apparatus (10) of the present embodiment processes the cooling load of the air conditioning unit (80) (specifically, the temperature of the indoor air in which the air conditioning unit (80) is installed is kept at a set temperature). The refrigerant flowing through the second suction pipe (34) is compressed in the first compression when the flow rate of the refrigerant necessary to exceed the refrigerant flow rate that can be sucked from the air conditioning heat exchanger (84) into the second compressor unit (112). It can be sucked into both the machine part (111) and the second compressor part (112).

When the refrigerant flowing through the second suction pipe (34) is sucked into both the first compressor part (111) and the second compressor part (112), the opening degree of the flow control valve (48) is changed. Thus, the flow rate of the refrigerant sucked into the first compressor part (111) through the connection pipe (47) can be adjusted. In this case, the flow rate of the refrigerant flowing through the air conditioning heat exchanger (84) is adjusted to an appropriate value according to the cooling load of the air conditioning unit (80) by adjusting the opening of the flow rate control valve (48). It becomes possible to set.

Further, the refrigeration apparatus (10) of the present embodiment processes the heating load of the air conditioning unit (80) (specifically, the temperature of the indoor air in which the air conditioning unit (80) is installed is kept at a set temperature). The second suction pipe when the flow rate of the refrigerant necessary for the refrigerant exceeds the flow rate of the refrigerant that the second compressor section (112) can suck from the outdoor heat exchanger (26) and supply to the air conditioning heat exchanger (84) The refrigerant flowing through (34) can be sucked into both the first compressor part (111) and the second compressor part (112).

When the refrigerant flowing through the second suction pipe (34) is sucked into both the first compressor part (111) and the second compressor part (112), the opening degree of the flow control valve (48) is changed. Thus, the flow rate of the refrigerant sucked into the first compressor part (111) through the connection pipe (47) can be adjusted. In this case, the flow rate of the refrigerant flowing through the air conditioning heat exchanger (84) is adjusted to an appropriate value according to the heating load of the air conditioning unit (80) by adjusting the opening of the flow rate control valve (48). It becomes possible to set.

Thus, in this embodiment, when the cooling load of the refrigeration unit (70) cannot be processed, the flow rate of the refrigerant flowing through the refrigeration heat exchanger (74) by adjusting the opening of the flow rate control valve (48). Can be set to a value according to the cooling load of the refrigeration unit (70). In the present embodiment, when the cooling load or the heating load of the air conditioning unit (80) cannot be processed only by the second compressor section (112), the air conditioning is performed by adjusting the opening degree of the flow control valve (48). It becomes possible to set the flow rate of the refrigerant flowing through the heat exchanger (84) to a value corresponding to the cooling load or the heating load of the air conditioning unit (80). Therefore, according to this embodiment, the cooling capacity of the refrigeration apparatus (10) can be appropriately controlled, and the usability of the refrigeration apparatus (10) can be improved.

-Modification of Embodiment 1-
The controller (120) of the present embodiment may perform the following operation as the first control operation. Here, the difference between the first control operation performed by the controller (120) of the present modification and the first control operation shown in FIG. 10 will be described.

As shown in FIG. 15, the controller (120) of the present modification performs the operation of step ST24 ′ instead of the operation of step ST24 of FIG. 10, and replaces the operation of step ST25 of FIG. Perform the action.

When the condition of step ST22 is not satisfied, the controller (120) of the present modified example sets the opening of the flow rate control valve (48) and the refrigerant pressure LP2 in the second suction pipe (34) in step ST24 ′. 2Adjust so that the target low pressure (0.85 MPa) is obtained. Further, in the next step ST25 ′, the controller (120) of the present modified example sets the operating capacity of the first compressor section (111) and the refrigerant pressure LP1 in the first suction pipe (32) to the first target low pressure. Adjust to (0.48 MPa).

The operation of the controller (120) in step ST24 ′ will be described in detail. When the refrigerant pressure LP2 in the second suction pipe (34) exceeds the second target low pressure, the controller (120) increases the opening degree of the flow control valve (48). When the opening degree of the flow control valve (48) increases, the flow rate of the refrigerant flowing from the second suction pipe (34) into the connection pipe (47) increases, and the pressure LP2 decreases. On the other hand, when the pressure LP2 is lower than the second target low pressure, the controller (120) reduces the opening of the flow control valve (48). When the opening degree of the flow rate control valve (48) decreases, the flow rate of the refrigerant flowing from the second suction pipe (34) into the connection pipe (47) decreases, and the pressure LP2 increases.

The operation of the controller (120) in step ST25 ′ will be described in detail. When the refrigerant pressure LP1 in the first suction pipe (32) exceeds the first target low pressure, the controller (120) increases the operating capacity of the first compressor unit (111). When the operating capacity of the first compressor section (111) increases, the flow rate of the refrigerant sucked from the first suction pipe (32) to the first compressor section (111) increases, and the pressure LP1 decreases. On the other hand, when the pressure LP1 is lower than the first target low pressure, the controller (120) decreases the operating capacity of the first compressor section (111). When the operating capacity of the first compressor section (111) decreases, the flow rate of the refrigerant sucked from the first suction pipe (32) into the first compressor section (111) decreases, and the pressure LP1 increases.

<< Embodiment 2 of the Invention >>
A second embodiment of the present invention will be described. The refrigeration apparatus (10) of the present embodiment is different from the refrigeration apparatus (10) of Embodiment 1 in the operation performed by the controller (120). Here, the difference between the operation performed by the controller (120) of the present embodiment and the operation performed by the controller (120) of the first embodiment will be described.

In the controller (120) of this embodiment, the reference capacity of the first compressor section (111) is set to the optimum capacity of the first compressor section (111), and the reference capacity of the second compressor section (112) is set. The optimum capacity of the second compressor section (112) is set. Here, the compression mechanism constituting the compressor (24, 25) has the highest efficiency when the rotation speed is a specific value (optimum rotation speed). Then, the operating frequency of the compressor (24, 25) when the rotation speed of the compression mechanism is the optimum rotation speed is set as the optimum frequency. In the present embodiment, the operating capacity of the first compressor section (111) becomes the optimal capacity when the operating frequency of the first compressor (24) is the optimal frequency, and the operating capacity of the second compressor section (112). Is the optimum capacity when the operating frequency of the second compressor (25) is the optimum frequency.

<Operation during refrigeration / cooling operation>
During the refrigeration / cooling operation, the controller (120) performs the operations shown in the flowcharts of FIGS. Here, the difference between the operation performed by the controller (120) of the present embodiment and the operation performed by the controller (120) of the first embodiment will be described.

As shown in FIG. 16, the controller (120) of the present embodiment replaces step ST05 in FIG. 9 with step ST05 ′, replaces step ST10 with FIG. 9 and replaces step ST10 ′ with step ST11 in FIG. Instead, step ST11 ′ is performed.

In step ST05 ′, the controller (120) determines whether or not the condition “the operation capacity of the second compressor section (112) is equal to or greater than the optimum capacity” is satisfied. When this condition is satisfied, if the cooling load of the air conditioning unit (80) is processed only by the second compressor section (112), the operation of the second compressor (25) constituting the second compressor section (112) is performed. It is in a situation where efficiency decreases. Therefore, the controller (120) performs the second control operation in step ST06. This second control operation will be described later. On the other hand, when this condition is not satisfied, the cooling load of the air conditioning unit (80) can be processed only by the second compressor unit (112). Therefore, in step ST07, the controller (120) fully closes the flow rate adjustment valve (48) and adjusts the operating capacity of the second compressor unit (112) based on the pressure LP2.

In step ST10 ′, the controller (120) determines whether or not the condition “the operation capacity of the first compressor unit (111) is equal to or greater than the optimum capacity” is satisfied. When this condition is satisfied, if the cooling load of the refrigeration unit (70) is processed only by the first compressor section (111), the operation of the first compressor (24) constituting the first compressor section (111) is performed. It is in a situation where efficiency decreases. Therefore, when the condition of step ST10 ′ is satisfied, the controller (120) performs the operation of step ST11 ′.

In step ST11 ′, the controller (120) determines whether or not the condition “the operation capacity of the second compressor section (112) is equal to or greater than the optimum capacity” is satisfied.

When the condition of step ST11 ′ is satisfied, the controller (120) controls the first compressor section (so that the refrigerant pressure LP1 in the first suction pipe (32) becomes the first target low pressure (0.48 MPa). 111) and the operation capacity of the second compressor section (112) are synchronously changed. Specifically, the controller (120) increases the operating frequency of the first compressor (24) and the operating frequency of the second compressor (25) by the same value when the pressure LP1 exceeds the first target low pressure. When the pressure LP1 is lower than the first target low pressure, the operating frequency of the first compressor (24) and the operating frequency of the second compressor (25) are decreased by the same value. The controller (120) sets the operating frequency of the first compressor (24) and the operating frequency of the second compressor (25) to the same value.

On the other hand, when the condition of step ST11 ′ is not satisfied, the controller (120) maintains the operating capacity of the first compressor unit (111) at the optimum capacity and presses the operating capacity of the second compressor unit (112). LP1 is adjusted to be the first target low pressure (0.48 MPa). Specifically, the controller (120) increases the operating frequency of the second compressor (25) when the pressure LP1 exceeds the first target low pressure, and increases the operating frequency of the second compressor (25) when the pressure LP1 falls below the first target low pressure. 2 Reduce the operating frequency of the compressor (25).

[First control operation]
Similar to the controller (120) of the first embodiment, the controller (120) of the present embodiment performs the first control operation in step ST02 of FIG. However, the first control operation performed by the controller (120) of the present embodiment is different from the first control operation performed by the controller (120) of the first embodiment. Here, the difference between the first control operation performed by the controller (120) of the present embodiment and the first control operation performed by the controller (120) of the first embodiment will be described.

As shown in FIG. 17, the controller (120) of the present embodiment performs step ST21 ′ in place of step ST21 in FIG. 10, and performs step ST22 ′ in place of step ST22 in FIG. Further, the controller (120) of the present embodiment performs the operations of step ST81, step ST82, and step ST83.

In step ST21 ′, the controller (120) determines whether or not the condition “the operation capacity of the second compressor section (112) is equal to or greater than the optimum capacity” is satisfied. When the condition of step ST21 ′ is satisfied, the controller (120) determines whether or not the condition that “the operating capacity of the first compressor unit (111) is equal to or larger than the optimum capacity” is satisfied in step ST22 ′. When step ST22 ′ is satisfied, the controller (120) determines whether or not the condition “the flow rate control valve (48) is open” is satisfied in step ST81.

If the condition of step ST81 is not satisfied, the flow rate control valve (48) is substantially fully closed. In this case, the cooling load of the refrigeration unit (70) can be processed only by the first compressor unit (111), and the cooling load of the air conditioning unit (80) can be processed only by the second compressor unit (112). . Therefore, in this case, the controller (120) adjusts the operating capacities of the first compressor unit (111) and the second compressor unit (112) in step ST83. Specifically, the controller (120) sets the operating capacity of the first compressor section (111) so that the refrigerant pressure LP1 in the first suction pipe (32) becomes the first target low pressure (0.48 MPa). Adjust. Further, the controller (120) adjusts the operating capacity of the second compressor section (112) so that the refrigerant pressure LP2 in the second suction pipe (34) becomes the second target low pressure (0.85 MPa). .

On the other hand, when the condition of step ST81 is satisfied, if the flow rate control valve (48) is already open and the cooling load of the refrigeration unit (70) is processed only by the first compressor section (111), the first compressor The operating efficiency of the first compressor (24) constituting the section (111) is reduced. Therefore, in this case, in step ST82, the controller (120) causes the first compressor section (111) so that the refrigerant pressure LP1 in the first suction pipe (32) becomes the first target low pressure (0.48 MPa). ) And the operation capacity of the second compressor section (112) are synchronously changed. Specifically, the controller (120) increases the operating frequency of the first compressor (24) and the operating frequency of the second compressor (25) by the same value when the pressure LP1 exceeds the first target low pressure. When the pressure LP1 is lower than the first target low pressure, the operating frequency of the first compressor (24) and the operating frequency of the second compressor (25) are decreased by the same value. The controller (120) sets the operating frequency of the first compressor (24) and the operating frequency of the second compressor (25) to the same value.

When the controller (120) performs the operation of step ST82, it next performs the operation of step ST23. The operation in step ST23 is the same as the operation in step ST23 in FIG.

[Second control operation]
Similar to the controller (120) of the first embodiment, the controller (120) of the present embodiment performs the second control operation in step ST06 of FIG. However, the second control operation performed by the controller (120) of the present embodiment is different from the second control operation performed by the controller (120) of the first embodiment. Here, the difference between the second control operation performed by the controller (120) of the present embodiment and the second control operation performed by the controller (120) of the first embodiment will be described.

As shown in FIG. 18, the controller (120) of the present embodiment performs step ST33 ′ in place of step ST33 in FIG. 11, and performs step ST34 ′ in place of step ST34 in FIG. Further, the controller (120) of the present embodiment performs the operation of step ST84.

In step ST33 ′, the controller (120) determines whether or not the condition “the operation capacity of the first compressor unit (111) is equal to or greater than the optimum capacity” is satisfied.

When the condition of step ST33 ′ is satisfied, the controller (120) controls the first compressor section (so that the refrigerant pressure LP2 in the second suction pipe (34) becomes the second target low pressure (0.85 MPa). 111) and the operation capacity of the second compressor section (112) are synchronously changed. Specifically, the controller (120) increases the operating frequency of the first compressor (24) and the operating frequency of the second compressor (25) by the same value when the pressure LP2 exceeds the second target low pressure. When the pressure LP2 is lower than the second target low pressure, the operating frequency of the first compressor (24) and the operating frequency of the second compressor (25) are decreased by the same value. The controller (120) sets the operating frequency of the first compressor (24) and the operating frequency of the second compressor (25) to the same value.

On the other hand, if the condition of step ST33 ′ is not satisfied, the controller (120) maintains the operating capacity of the second compressor section (112) at the optimum capacity, and the operating capacity of the first compressor section (111) is set to the pressure. LP2 is adjusted to be the second target low pressure (0.85 MPa). Specifically, the controller (120) increases the operating frequency of the second compressor (25) when the pressure LP2 exceeds the second target low pressure, and increases the operating frequency of the second compressor (25) when the pressure LP2 falls below the second target low pressure. 2 Reduce the operating frequency of the compressor (25).

In step ST34 ′, the controller (120) determines whether or not a condition that “the operation capacity of the first compressor unit (111) is equal to or greater than the optimum capacity” is satisfied. When the condition of step ST34 ′ is not satisfied, there is room for increasing the operating capacity of the first compressor section (111). Therefore, in this case, the controller (120) performs the operations of step ST36 and step ST37 as in the first embodiment. On the other hand, when the condition of step ST34 ′ is satisfied, the controller (120) causes the refrigerant pressure LP1 in the first suction pipe (32) to be the first target low pressure (0.48 MPa) in step ST84. The operating capacity of the first compressor unit (111) and the operating capacity of the second compressor unit (112) are changed synchronously. The operation performed by the controller (120) in step ST84 is the same as the operation performed by the controller (120) in step ST82 of FIG.

When the controller (120) performs the operation in step ST84, the controller (120) next performs the operation in step ST35. The operation in step ST35 is the same as the operation in step ST35 in FIG.

<Operation during refrigeration / heating operation>
During the refrigeration / heating operation, the controller (120) performs the operations shown in the flowcharts of FIGS. Here, the difference between the operation performed by the controller (120) of the present embodiment and the operation performed by the controller (120) of the first embodiment will be described.

As shown in FIG. 19, the controller (120) of this embodiment replaces step ST46 in FIG. 12 with step ST46 ′, replaces step ST47 in FIG. 12 with step ST47 ′, and changes to step ST52 in FIG. Instead, step ST52 ′ is performed, and step ST53 ′ is performed instead of step ST53 in FIG.

In step ST46 ′, the controller (120) determines whether or not a condition that “the operating capacity of the first compressor unit (111) is equal to or greater than the optimum capacity” is satisfied. When the condition of step ST46 ′ is not satisfied, the cooling load of the refrigeration unit (70) can be processed only by the first compressor unit (111). Therefore, in this case, the controller (120) performs the operations of step ST49, step ST50, and step ST51. These operations are the same as the operations in step ST49, step ST50, and step ST51 in FIG. 12, respectively. On the other hand, when the condition of step ST46 ′ is satisfied, if the cooling load of the refrigeration unit (70) is processed only by the first compressor unit (111), the first compressor constituting the first compressor unit (111) (24) The operating efficiency is in a situation that decreases. Therefore, in this case, the controller (120) performs the operation of step ST47 ′.

The operation performed by the controller (120) in step ST47 ′ is the same as the operation performed by the controller (120) in step ST11 ′ of FIG. That is, in step ST47 ′, the controller (120) determines whether or not the condition “the operation capacity of the second compressor section (112) is equal to or greater than the optimum capacity” is satisfied. When this condition is satisfied, the controller (120) causes the first compressor section (111) so that the refrigerant pressure LP1 in the first suction pipe (32) becomes the first target low pressure (0.48 MPa). ) And the operation capacity of the second compressor section (112) are synchronously changed. On the other hand, if this condition is not satisfied, the controller (120) maintains the operating capacity of the first compressor section (111) at the optimum capacity, and the operating capacity of the second compressor section (112) is set to the pressure LP1. 1 Adjust the pressure to become the target low pressure.

In step ST52 ′, the controller (120) determines whether or not the condition “the operation capacity of the second compressor section (112) is equal to or greater than the optimum capacity” is satisfied. When the condition of step ST52 ′ is not satisfied, the heating load of the air conditioning unit (80) can be processed only by the second compressor section (112). Therefore, in this case, the controller (120) performs the operations of step ST55 and step ST56. These operations are the same as those in step ST55 and step ST56 in FIG. 12, respectively. On the other hand, when the condition of step ST52 ′ is satisfied, if the heating load of the air conditioning unit (80) is processed only by the second compressor section (112), the second compressor constituting the second compressor section (112) (25) The operating efficiency is in a situation that decreases. Therefore, in this case, the controller (120) performs the operation of step ST53 ′.

In step ST53 ′, the controller (120) determines whether or not the condition “the operation capacity of the first compressor unit (111) is equal to or greater than the optimum capacity” is satisfied.

When the condition of step ST53 ′ is satisfied, the controller (120) includes the first compressor section (111) so that the refrigerant condensation temperature Tc in the air conditioning heat exchanger (84) becomes the target temperature (55 ° C.). And the operation capacity of the second compressor section (112) are synchronously changed. Specifically, when the refrigerant condensing temperature Tc exceeds the target temperature (55 ° C.), the controller (120) operates the first compressor (24) and the second compressor (25). If the frequency is reduced by the same value and the refrigerant condensing temperature Tc is below the target temperature (55 ° C.), the operating frequency of the first compressor (24) and the operating frequency of the second compressor (25) Is increased by the same value. The controller (120) sets the operating frequency of the first compressor (24) and the operating frequency of the second compressor (25) to the same value.

On the other hand, if the condition of step ST53 ′ is not satisfied, the controller (120) maintains the operating capacity of the second compressor section (112) at the optimum capacity and the operating capacity of the first compressor section (111) as the refrigerant. The condensation temperature Tc is adjusted to the target temperature (55 ° C.). Specifically, the controller (120) decreases the operating frequency of the first compressor (24) when the refrigerant condensing temperature Tc exceeds the target temperature, and when the refrigerant condensing temperature Tc falls below the target temperature. The operating frequency of the first compressor (24) is increased.

[Control action for the first concurrent operation]
Similar to the controller (120) of the first embodiment, the controller (120) of the present embodiment performs a control operation for the first concurrent operation. However, the control operation for the first concurrent operation performed by the controller (120) of the present embodiment is different from the control operation for the first concurrent operation performed by the controller (120) of the first embodiment. Here, the difference between the control operation for the first concurrent operation performed by the controller (120) of the present embodiment and the control operation for the first concurrent operation performed by the controller (120) of the first embodiment will be described.

As shown in FIG. 20, the controller (120) of this embodiment performs step ST62 ′ in place of step ST62 in FIG. 13, and performs step ST63 ′ in place of step ST63 in FIG.

In Step ST62 ′, the controller (120) determines whether or not a condition that “the operation capacity of the first compressor unit (111) is equal to or larger than the optimum capacity” is satisfied. When the condition of step ST62 ′ is not satisfied, the cooling load of the refrigeration unit (70) can be processed only by the first compressor unit (111). Therefore, in this case, the controller (120) performs the operations of step ST65 and step ST66. These operations are the same as those in step ST65 and step ST66 in FIG. On the other hand, when the condition of step ST62 ′ is satisfied, if the cooling load of the refrigeration unit (70) is processed only by the first compressor unit (111), the first compressor constituting the first compressor unit (111) (24) The operating efficiency is in a situation that decreases. Therefore, in this case, the controller (120) performs the operation of step ST63 ′.

The operation of step ST63 ′ is the same as the operation of step ST47 ′ in FIG. In step ST63 ′, the controller (120) determines whether or not the condition that “the operating capacity of the first compressor unit (111) is equal to or greater than the optimum capacity” is satisfied. When this condition is not satisfied, the controller (120) causes the first compressor section (111) to have the refrigerant pressure LP1 in the first suction pipe (32) at the first target low pressure (0.48 MPa). The operating capacity and the operating capacity of the second compressor unit (112) are changed synchronously. On the other hand, if this condition is not satisfied, the controller (120) maintains the operating capacity of the first compressor section (111) at the optimum capacity, and the operating capacity of the second compressor section (112) is set to the pressure LP1. 1 Adjust the pressure to become the target low pressure.

[Control action for second concurrent operation]
Similar to the controller (120) of the first embodiment, the controller (120) of the present embodiment performs a control operation for the second concurrent operation. However, the control operation for the second concurrent operation performed by the controller (120) of the present embodiment is different from the control operation for the second concurrent operation performed by the controller (120) of the first embodiment. Here, the difference between the control operation for the second concurrent operation performed by the controller (120) of the present embodiment and the control operation for the second concurrent operation performed by the controller (120) of the first embodiment will be described.

As shown in FIG. 21, the controller (120) of this embodiment performs step ST72 ′ in place of step ST72 in FIG. 14, and performs step ST73 ′ in place of step ST73 in FIG.

In step ST72 ′, the controller (120) determines whether or not a condition that “the operation capacity of the first compressor unit (111) is equal to or greater than the optimum capacity” is satisfied. When the condition of step ST72 ′ is not satisfied, the cooling load of the refrigeration unit (70) can be processed only by the first compressor unit (111). Therefore, in this case, the controller (120) performs the operations of step ST75 and step ST76. These operations are the same as those in step ST75 and step ST76 in FIG. 14, respectively. On the other hand, when the condition of step ST72 ′ is satisfied, if the cooling load of the refrigeration unit (70) is processed only by the first compressor unit (111), the first compressor constituting the first compressor unit (111) (24) The operating efficiency is in a situation that decreases. Therefore, in this case, the controller (120) performs the operation of step ST73 ′.

The operation of step ST73 ′ is the same as the operation of step ST63 ′ of FIG. Specifically, in step ST73 ′, the controller (120) determines whether or not a condition that “the operating capacity of the first compressor unit (111) is equal to or greater than the optimum capacity” is satisfied. When this condition is not satisfied, the controller (120) causes the first compressor section (111) to have the refrigerant pressure LP1 in the first suction pipe (32) at the first target low pressure (0.48 MPa). The operating capacity and the operating capacity of the second compressor unit (112) are changed synchronously. On the other hand, if this condition is not satisfied, the controller (120) maintains the operating capacity of the first compressor section (111) at the optimum capacity, and the operating capacity of the second compressor section (112) is set to the pressure LP1. 1 Adjust the pressure to become the target low pressure.

<< Other Embodiments >>
In the refrigeration apparatus (10) of

Embodiments

1 and 2, each of the first compressor unit (111) and the second compressor unit (112) is configured by a single compressor (24, 25). The first compressor unit (111) may be configured by a plurality of compressors, and the second compressor unit (112) may be configured by a plurality of compressors.

Here, in the refrigeration apparatus (10) of the present modification, the first compressor unit (111) is configured by two compressors, and the second compressor unit (112) is configured by one compressor. A case will be described as an example. Here, the refrigeration apparatus (10) of the present modification will be described with respect to differences from the refrigeration apparatus (10) of the first embodiment.

As shown in FIG. 22, in the refrigeration apparatus (10) of the present modification, the first compressor section (111) is constituted by the first compressor (24) and the third compressor (113), and the second compression The machine part (112) is constituted by the second compressor (25). The third compressor (113) is a scroll type hermetic compressor. Although not shown, in the third compressor (113), a compression mechanism that is a scroll type fluid machine and an electric motor that drives the compression mechanism are housed in a hermetically sealed casing. The AC of the commercial power supply is supplied as it is to the electric motor of the third compressor (113). Therefore, the third compressor (113) has a constant rotational speed of the compression mechanism and a constant operating capacity.

In this modification, the first discharge pipe (31) is constituted by a main discharge pipe (31a) and an auxiliary discharge pipe (31b), and the first suction pipe (32) is formed by a main suction pipe (32a) and an auxiliary suction pipe ( 32b).

The main discharge pipe (31a) connects the discharge part of the first compressor (24) to the first port of the first four-way switching valve (27). In the main discharge pipe (31a), in order from the first compressor (24) to the first four-way switching valve (27), a first discharge temperature sensor (90), a first check valve (CV1), A discharge pressure sensor (91) is provided.

The auxiliary discharge pipe (31b) connects the discharge part of the third compressor (113) between the discharge pressure sensor (91) and the first four-way switching valve (27) in the main discharge pipe (31a). The auxiliary discharge pipe (31b) is provided with a third discharge temperature sensor (115) and a seventh check valve (CV7) in order from the third compressor (113) to the main discharge pipe (31a). ing. The third discharge temperature sensor (115) detects the temperature of refrigerant discharged from the third compressor (113). The seventh check valve (CV7) allows the flow of the refrigerant in the direction of the arrow shown in FIG. 22 and prohibits the flow of the refrigerant in the opposite direction. In the present modification, the second discharge pipe (33) is connected to the downstream side of the seventh check valve (CV7) in the auxiliary discharge pipe (31b).

In this modification, the first suction pipe (32) is constituted by a main discharge pipe (31a) and an auxiliary discharge pipe (31b), and the first suction pipe (32) is formed by a main suction pipe (32a) and an auxiliary suction pipe ( 32b). The main suction pipe (32a) connects the suction part of the first compressor (24) to the refrigeration side gas shut-off valve (13). The main suction pipe (32a) is provided with a first suction pressure sensor (94) and a first suction temperature sensor (93) in order from the refrigeration side gas shut-off valve (13) to the first compressor (24). It has been. The auxiliary suction pipe (32b) connects the suction part of the third compressor (113) to the downstream side of the first suction temperature sensor (93) in the main suction pipe (32a).

The third introduction pipe (114) is added to the injection circuit (55) of this modification. One end of the third introduction pipe (114) is connected to the upstream side of the first injection valve (61) in the first introduction pipe (58), and the other end is connected to the third compressor (113). The third introduction pipe (114) supplies intermediate pressure refrigerant to the compression chamber in the middle of compression of the third compressor (113). The third introduction pipe (114) is provided with a third injection valve (63). The third injection valve (63) is an electronic expansion valve having a variable opening, and adjusts the flow rate of the intermediate-pressure refrigerant introduced into the third compressor (113).

In this modification, the operating capacity of the first compressor section (111) is such that the operating frequency of the first compressor (24) is the upper limit value and the third compressor (113) is operating. Maximum capacity. The operating capacity of the first compressor unit (111) is the optimal capacity when the operating frequency of the first compressor (24) is the optimal frequency and the third compressor (113) is operating. Become.

As described above, the present invention is useful for a refrigeration apparatus provided with a plurality of types of usage-side heat exchangers.

10 Refrigeration equipment 11 Refrigerant circuit 24 First compressor (compressor)
25 Second compressor (compressor)
26 Outdoor heat exchanger (heat source side heat exchanger)
32 First suction pipe 34 Second suction pipe 47 Connection pipe 48 Flow control valve (control valve)
74 Refrigerated heat exchanger (first use side heat exchanger)
84 Air-conditioning heat exchanger (second-use-side heat exchanger)
110 Switching mechanism 111 First compressor section 112 Second compressor section

Claims

A first compressor section (111) and a second compressor section (112) each constituted by one or a plurality of compressors (24, 25), a heat source side heat exchanger (26), and a first A refrigeration apparatus comprising a refrigerant circuit (11) having a utilization side heat exchanger (74) and a second utilization side heat exchanger (84) to perform a refrigeration cycle,
The refrigerant circuit (11)
A first suction pipe (32) connected to the first compressor part (111) and communicating the first compressor part (111) with the first use side heat exchanger (74);
A second suction pipe (34) connected to the second compressor section (112);
Switching between a state in which the second suction pipe (34) communicates with the second use side heat exchanger (84) and a state in which the second suction pipe (34) communicates with the heat source side heat exchanger (26). A switching mechanism (110) for
A connection pipe (47) having one end connected to the first suction pipe (32) and the other end connected to the second suction pipe (34);
A refrigerating apparatus comprising: a variable opening control valve (48) provided in the connection pipe (47).
In claim 1,
First cooling in which the heat source side heat exchanger (26) functions as a condenser, and both the first usage side heat exchanger (74) and the second usage side heat exchanger (84) function as an evaporator. Operation can be performed,
A controller (120) for adjusting the operating capacity of the first compressor part (111) and the second compressor part (112) and the opening of the control valve (48);
The controller (120) is configured to control the control valve when operating capacities of the first compressor unit (111) and the second compressor unit (112) are lower than a predetermined reference capacity during the first cooling operation. (48) is kept fully closed, the operating capacity of the first compressor section (111) is adjusted so that the refrigerant pressure in the first suction pipe (32) becomes the first target low pressure, and the second suction pipe is adjusted. The refrigerating apparatus, wherein the operating capacity of the second compressor section (112) is adjusted so that the refrigerant pressure in the pipe (34) becomes a second target low pressure higher than the first target low pressure.
In claim 2,
The controller (120)
When the operating capacity of the first compressor unit (111) is lower than the reference capacity and the operating capacity of the second compressor unit (112) is equal to or higher than the reference capacity during the first cooling operation,
The opening of the control valve (48) is adjusted so that the refrigerant pressure in the first suction pipe (32) becomes the first target low pressure, and the refrigerant pressure in the second suction pipe (34) becomes the second target pressure. The operation of adjusting the operating capacity of the first compressor section (111) so as to be low, or the adjusting valve (48) so that the refrigerant pressure of the second suction pipe (34) becomes the second target low pressure And adjusting the operating capacity of the first compressor section (111) so that the refrigerant pressure in the first suction pipe (32) becomes the first target low pressure. Refrigeration equipment.
In claim 2 or 3,
The controller (120) includes the first compressor unit (111) and the second compressor unit (112) when the operating capacities of the first compressor unit (111) and the second compressor unit (112) are equal to or greater than a predetermined reference capacity during the first cooling operation. The refrigerating apparatus characterized by adjusting the opening degree of the said control valve (48) so that the refrigerant | coolant pressure of 1 suction piping (32) may become the said 1st target low pressure.
In any one of Claims 2 thru | or 4,
The second heat source side heat exchanger (26) functions as a condenser, the second use side heat exchanger (84) functions as an evaporator, and the first use side heat exchanger (74) is suspended. Cooling operation can be performed,
The controller (120) maintains the control valve (48) in a fully closed state when the operating capacity of the second compressor section (112) is lower than the reference capacity during the second cooling operation, The operating capacity of the second compressor section (112) is adjusted so that the first compressor section (111) is stopped and the refrigerant pressure in the second suction pipe (34) becomes the second target low pressure. A refrigeration apparatus characterized by that.
In claim 5,
When the operating capacity of the second compressor section (112) is greater than or equal to the reference capacity during the second cooling operation, the controller (120) has a refrigerant pressure in the first suction pipe (32) of The opening degree of the control valve (48) is adjusted so as to become one target low pressure, and the first compressor section (111) so that the refrigerant pressure in the second suction pipe (34) becomes the second target low pressure. And the operating capacity of the said 2nd compressor part (112) is adjusted, The freezing apparatus characterized by the above-mentioned.
In claim 6,
When the operating capacity of the first compressor unit (111) and the second compressor unit (112) is greater than or equal to the reference capacity during the second cooling operation, the controller (120) The refrigerating apparatus characterized by adjusting the opening degree of the control valve (48) so that the refrigerant pressure in the suction pipe (32) becomes the first target low pressure.
In any one of Claims 2 thru | or 7,
The heat source side heat exchanger (26) functions as a condenser, the first usage side heat exchanger (74) functions as an evaporator, and the second usage side heat exchanger (84) is deactivated. Cooling operation can be performed,
The controller (120) fully closes the control valve (48) when the operating capacity of the first compressor unit (111) is lower than the reference capacity during the third cooling operation, Adjusting the operating capacity of the first compressor part (111) so that the refrigerant pressure in one suction pipe (32) becomes the first target low pressure, and keeping the second compressor part (112) in a stopped state. A refrigeration apparatus characterized by.
In claim 8,
When the operating capacity of the first compressor unit (111) is equal to or greater than the reference capacity during the third cooling operation, the controller (120) fully opens the control valve (48), and The refrigeration is characterized in that the operating capacities of the first compressor section (111) and the second compressor section (112) are adjusted so that the refrigerant pressure in one suction pipe (32) becomes the first target low pressure. apparatus.
In claim 1,
The heat source side heat exchanger (26) and the second usage side heat exchanger (84) function as a condenser, and the first usage side heat exchanger (74) functions as an evaporator. Is feasible,
A controller (120) for adjusting the operating capacity of the first compressor part (111) and the second compressor part (112) and the opening of the control valve (48);
When the operating capacity of the first compressor section (111) falls below a predetermined reference capacity during the first concurrent operation, the controller (120) has a predetermined refrigerant pressure in the first suction pipe (32). The refrigeration apparatus is characterized in that the operating capacity of the first compressor section (111) is adjusted so that the target low pressure is maintained, and the second compressor section (112) is kept stopped.
In claim 10,
The controller (120) maintains the control valve (48) in a fully open state when the operating capacity of the first compressor unit (111) is equal to or greater than the reference capacity during the first concurrent operation. The refrigeration system characterized in that the operating capacities of the first compressor part (111) and the second compressor part (112) are adjusted so that the refrigerant pressure in the first suction pipe (32) becomes the target low pressure. .
In claim 1,
The second heat source side heat exchanger (26) is deactivated, the second usage side heat exchanger (84) functions as a condenser, and the first usage side heat exchanger (74) functions as an evaporator. Co-operation can be performed,
A controller (120) for adjusting the operating capacity of the first compressor part (111) and the second compressor part (112) and the opening of the control valve (48);
The controller (120) maintains the control valve (48) in a fully closed state when the operating capacity of the first compressor unit (111) is lower than a predetermined reference capacity during the second concurrent operation, The operating capacity of the first compressor section (111) is adjusted so that the refrigerant pressure in the first suction pipe (32) becomes a predetermined target low pressure, and the second compressor section (112) is kept in a stopped state. A refrigeration apparatus characterized by that.
In claim 12,
The controller (120) maintains the control valve (48) in a fully opened state when the operating capacity of the first compressor unit (111) is equal to or greater than the reference capacity during the second concurrent operation. The refrigeration apparatus characterized by adjusting the operating capacity of the second compressor section (112) so that the refrigerant pressure in the first suction pipe (32) becomes the target low pressure.
In claim 1,
The third usage side heat exchanger (84) functions as a condenser and the heat source side heat exchanger (26) and the first usage side heat exchanger (74) function as an evaporator. Is feasible,
A controller (120) for adjusting the operating capacity of the first compressor part (111) and the second compressor part (112) and the opening of the control valve (48);
The controller (120) keeps the control valve (48) in a fully closed state when the operating capacity of the first compressor section (111) falls below a predetermined reference capacity during the third concurrent operation, The operating capacity of the first compressor section (111) is adjusted so that the refrigerant pressure in the first suction pipe (32) becomes a predetermined target low pressure, and the refrigerant in the second usage side heat exchanger (84) is adjusted. The refrigeration apparatus characterized by adjusting the operating capacity of the second compressor section (112) so that the condensation temperature becomes a predetermined target temperature.
In claim 14,
The controller (120) maintains the control valve (48) in a fully opened state when the operating capacity of the first compressor unit (111) is equal to or greater than the reference capacity during the third concurrent operation, The refrigeration apparatus characterized by adjusting the operating capacity of the second compressor section (112) so that the refrigerant pressure in the first suction pipe (32) becomes the target low pressure.
In claim 1,
The heating operation in which the second use side heat exchanger (84) functions as a condenser, the heat source side heat exchanger (26) functions as an evaporator, and the first use side heat exchanger (74) is stopped. Is possible and
A controller (120) for adjusting the operating capacity of the first compressor part (111) and the second compressor part (112) and the opening of the control valve (48);
The controller (120) keeps the control valve (48) in a fully closed state when the operating capacity of the second compressor section (112) falls below a predetermined reference capacity during the heating operation, The refrigeration apparatus, wherein the operating capacity of the second compressor section (112) is adjusted so that the condensation temperature of the refrigerant in the two usage side heat exchanger (84) becomes a predetermined target temperature.
In claim 16,
When the operating capacity of the second compressor section (112) becomes equal to or greater than the reference capacity during the heating operation, the controller (120) opens the control valve (48) to fully open the second usage side heat. A refrigerating apparatus, wherein an operating capacity of the first compressor section (111) is adjusted so that a refrigerant condensing temperature in the exchanger (84) becomes the target temperature.