JP2002277097A - Refrigerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a refrigerator capable of responding to a user's desire of most preferentially reducing a consumption energy in the refrigerator for executing both air conditioning and a cold storage. SOLUTION: The refrigerator (10) comprises a first indoor unit (12), a second indoor unit (13), a cold storage unit (14), and a cascade unit (15) connected to an outdoor unit (11). The first unit (12) switches to operate cooling and heating. The second unit (13) exclusively executes the cooling. The unit (14) cools the air in a cabinet of a showcase. The refrigerator (19) further comprises a controller (200) for controlling the volume of a compressor unit (40). In this case, the controller (200) sets the volume of the unit (40) to a smaller one of a target decided based on a low pressure of a high-temperature side refrigerant circuit (20) or a target decided based on a difference between an indoor temperature and the set temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a refrigeration apparatus,
In particular, the present invention relates to an apparatus having a heat exchanger for air conditioning and a heat exchanger for refrigeration.

[0002]

2. Description of the Related Art Hitherto, a refrigerating apparatus for performing a refrigerating cycle has been known, and is widely used as an air conditioner for cooling and heating a room or a refrigerator for storing foods and the like.
Some refrigeration systems are configured to perform both air conditioning and refrigeration, as disclosed in WO 98/542600. This type of refrigeration apparatus is suitable for being installed in, for example, a convenience store. This is because the air conditioning in the store and the cooling of the showcase can be performed only by installing one refrigeration apparatus.

In the above refrigeration system, when the load of air conditioning and the load of refrigeration are simultaneously maximized, the refrigeration capacity may be insufficient. In view of the above, conventionally, from the viewpoint of emphasizing the prevention of damage to refrigerated products, it is unavoidable that the air conditioning capacity will be insufficient, and the refrigeration capacity has been allocated to cooling showcases and the like.

[0004]

However, it is not always the case that the cooling of a showcase or the like must always be given the highest priority, and depending on the use situation of the user, it is necessary to reduce the energy required for operating the refrigeration system. Is sometimes emphasized. However, in the conventional refrigeration system, even if the energy consumption of the refrigeration system increases, the operation that places importance on cooling of the showcase or the like is performed. There was a problem of inviting.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a refrigeration system that performs both air conditioning and refrigeration, and a user's desire to give top priority to reduction of energy consumption. It is to provide what can respond to.

[0006]

A first solution of the present invention is directed to a refrigerating apparatus for circulating a refrigerant in a refrigerant circuit (20) to perform a refrigeration cycle. The refrigerant circuit (20) includes a variable capacity compressor means (40) having at least one compressor (41, 42) and a heat source for air conditioning for generating conditioned air for cooling and heating. While the exchanger (81) is connected to the refrigeration heat exchanger (101) for generating cooling air to be supplied to the inside of the refrigeration facility, the low pressure of the refrigerant in the refrigerant circuit (20) is detected. Low-pressure pressure detecting means (74), indoor air temperature detecting means (84) for detecting the indoor air temperature to which the conditioned air generated by the air-conditioning heat exchanger (81) is supplied, and compressor means (40) A target value determined based on the detected pressure of the low-pressure pressure detecting means (74) or a target value determined based on the difference between the detected temperature of the indoor air temperature detecting means (84) and the input set temperature. Control means (200) for adjusting to the smaller one of the two.

A second solution taken by the present invention is the air conditioner heat exchanger (81) according to the first solution, wherein a heating operation is performed by the air conditioner heat exchanger (81) to generate conditioned air for heating. 81) to condense the refrigerant and refrigerate the heat exchanger (10
The refrigeration cycle is performed by evaporating the refrigerant in 1).

A third solution taken by the present invention is directed to a refrigerating apparatus that performs a refrigerating cycle by circulating a refrigerant in a refrigerant circuit (20). The refrigerant circuit (20) includes a variable capacity compressor means (40) having at least one compressor (41, 42) and a heat source for air conditioning for generating conditioned air for cooling and heating. Exchanger (81) and a refrigeration heat exchanger (10
In the heating operation in which the air conditioning heat exchanger (81) generates conditioned air for heating, the refrigerant is condensed by the air conditioning heat exchanger (81) and the refrigeration heat exchanger (10) is connected.
A control means (200) for controlling the operation of the refrigeration apparatus so that the amount of heat absorbed and the amount of heat radiated by the refrigerant circulating in the refrigerant circuit (20) during the heating operation are balanced, while performing the refrigeration cycle by evaporating the refrigerant in 1). Is provided.

A fourth solution taken by the present invention is the heat exchanger (91) according to the third solution, wherein the refrigerant circuit (20) has a cooling-only heat exchanger (91) for generating only conditioned air for cooling.
While the control means (200) is connected to the compressor means (4
0), the amount of air blown to the air-conditioning heat exchanger (81), or the amount of air blown to the cooling only heat exchanger (91) to adjust the amount of heat absorbed by the refrigerant in the refrigerant circuit (20) during the heating operation. And the amount of heat radiation is balanced.

According to a fifth aspect of the present invention, in the fourth aspect of the present invention, there is provided an indoor air temperature detecting device for detecting an air temperature in a room to which the conditioned air generated by the air conditioning heat exchanger (81) is supplied. Means (84) while controlling means (200)
When increasing the heat radiation amount of the refrigerant in the refrigerant circuit (20) during the heating operation, the capacity of the compressor means (40) is determined based on the difference between the detected temperature of the room temperature detecting means (84) and the input set temperature. It is configured to adjust to the target value determined in advance.

According to a sixth aspect of the present invention, in the above fourth or fifth aspect, the control means (200) comprises:
When increasing the heat radiation amount of the refrigerant in the refrigerant circuit (20) during the heating operation, the capacity of the compressor means (40) is increased by the air flow to the air-conditioning heat exchanger (81) and the air flow to the cooling-only heat exchanger (91). In addition to changing the air flow rate, the air-conditioning heat exchanger (8
The configuration is such that the amount of air blown to 1) is changed in preference to the amount of air blown to the cooling only heat exchanger (91).

According to a seventh aspect of the present invention, in the fourth aspect, the control means (200) is provided for exclusive use in cooling when reducing the amount of heat release of the refrigerant in the refrigerant circuit (20) during the heating operation. The air flow to the heat exchanger (91) is changed prior to the air flow to the air conditioning heat exchanger (81) and the capacity of the compressor means (40), and the air flow to the air conditioning heat exchanger (81) is changed. Of the compressor means (40) is changed prior to the capacity of the compressor means (40).

According to an eighth aspect of the present invention, in accordance with the third aspect, the ventilation for introducing outside air into a room to which the conditioned air generated by the air conditioning heat exchanger (81) is supplied. Control means (200) for adjusting the capacity of the compressor means (40), the amount of air blown to the air-conditioning heat exchanger (81), or the amount of air blown by the ventilation blower (87). Thus, the amount of heat absorbed and the amount of heat released by the refrigerant in the refrigerant circuit (20) during the heating operation are balanced.

In the first solution, the compressor means (40), the heat exchanger for air conditioning (81), and the heat exchanger for refrigeration (101) are connected to the refrigerant circuit (20). Is done. In the refrigerant circuit (20), the refrigerant circulates, and a vapor compression refrigeration cycle is performed. Low pressure of the refrigerant in the refrigerant circuit (20),
That is, of the refrigerant circulating in the refrigerant circuit (20), the pressure of the refrigerant evaporated by the evaporator and drawn into the compressor means (40) is detected by the low pressure detection means (74).

The compressor means (40) has at least one compressor (41, 42), and its capacity can be changed. That is, the compressor means (40) is a compressor (41, 42)
The capacity of the compressor itself can be changed, or multiple compressors (4
The capacity is variable by changing the number of operating units (1, 42).

The air conditioning heat exchanger (81) is for producing conditioned air. When producing conditioned air for cooling, the air-conditioning heat exchanger (81) functions as an evaporator to cool the air. On the other hand, when producing conditioned air for heating,
The air-conditioning heat exchanger (81) functions as a condenser to heat the air. The generated conditioned air is supplied to, for example, a convenience store or the like, and is used for cooling or heating. The room temperature at which the conditioned air generated by the air conditioning heat exchanger (81) is supplied to perform cooling and heating is detected by the room temperature detection means (84).

The refrigerating heat exchanger (101) is for producing cooling air. Refrigeration heat exchanger (101)
It functions as an evaporator and cools the air throughout the year. The cooling air generated by the refrigeration heat exchanger (101) is supplied to refrigeration equipment such as a showcase, a refrigerator, and a freezer.

In the present solution, the control means (20
0) is provided. The control means (200) includes the compressor means (4
The capacity control of 0) is performed. At this time, the control means (200) sets the target value for the capacity control of the compressor means (40) based on the value based on the detected pressure of the low-pressure pressure detecting means (74) and the detected temperature of the indoor air temperature detecting means (84). Two values based on the difference between the set temperatures input by the user or the like are determined. Then, the control means (200) adjusts the capacity of the compressor means (40) such that the capacity of the compressor means (40) becomes the smaller of the two target values.

In the second solution, during the heating operation, the air conditioning heat exchanger (81) functions as a condenser, and the refrigeration heat exchanger (101) functions as an evaporator. Specifically, in the air-conditioning heat exchanger (81), the refrigerant discharged from the compressor means (40) releases heat to indoor air and condenses. on the other hand,
In the refrigerating heat exchanger (101), the depressurized refrigerant absorbs heat from the internal air and evaporates.

In the third solution, the compressor means (4
0), a heat exchanger for air conditioning (81), and a heat exchanger for refrigeration (10
1) are connected to the refrigerant circuit (20). Refrigerant circuit (2
In 0), the refrigerant circulates, and a vapor compression refrigeration cycle is performed. That is, in the refrigerant circuit (20), the refrigerant circulates while alternately repeating the process of radiating heat and condensing and the process of absorbing heat and evaporating.

The compressor means (40) has at least one compressor (41, 42), and its capacity can be changed. That is, the compressor means (40) is a compressor (41, 42)
The capacity of the compressor itself can be changed, or multiple compressors (4
The capacity is variable by changing the number of operating units (1, 42).

The air-conditioning heat exchanger (81) is for producing conditioned air. When producing conditioned air for cooling, the air-conditioning heat exchanger (81) functions as an evaporator to cool the air. On the other hand, when producing conditioned air for heating,
The air-conditioning heat exchanger (81) functions as a condenser to heat the air. The generated conditioned air is supplied to, for example, a convenience store or the like, and is used for cooling or heating.

The refrigerating heat exchanger (101) is for generating cooling air. Refrigeration heat exchanger (101)
It functions as an evaporator and cools the air throughout the year. The cooling air generated by the refrigeration heat exchanger (101) is supplied to refrigeration equipment such as a showcase, a refrigerator, and a freezer.

In this solution, during the heating operation, the air-conditioning heat exchanger (81) functions as a condenser, and the refrigeration heat exchanger (101) functions as an evaporator. Specifically, in the air-conditioning heat exchanger (81), the refrigerant discharged from the compressor means (40) releases heat to indoor air and condenses. On the other hand, in the refrigeration heat exchanger (101), the depressurized refrigerant absorbs heat from the air in the refrigerator and evaporates.

In the present solution, the refrigerating apparatus is provided with control means (200). The control means (200) controls the operation of the refrigeration system. Specifically, the control means (200) controls the operation of the refrigeration apparatus so that the amount of heat released and the amount of heat absorbed by the refrigerant circulating in the refrigerant circuit (20) during the heating operation are balanced.

In the fourth solution, the cooling only heat exchanger (91) is connected to the refrigerant circuit (20). The cooling only heat exchanger (91) is for generating only conditioned air for cooling. That is, unlike the air-conditioning heat exchanger (81), the cooling-specific heat exchanger (91) functions exclusively as an evaporator and performs only air cooling. For example, a room with a large heat load, such as a kitchen, may be required to be cooled throughout the year. Therefore, in such a room, the conditioned air for cooling generated by the cooling heat exchanger (91) is supplied, and cooling is performed even in winter.

In the present invention, the control means (200)
Increases or decreases the capacity of the compressor means (40), the amount of air blown to the air-conditioning heat exchanger (81), or the amount of air blown to the cooling only heat exchanger (91). The control means (200) adjusts these to increase or decrease the amount of heat radiation or the amount of heat absorbed by the refrigerant circulating in the refrigerant circuit (20) to balance the two.

In the fifth solving means, the refrigerating apparatus is provided with an indoor air temperature detecting means (84). The room temperature detecting means (84) detects the temperature of the room in which the conditioned air generated by the air conditioning heat exchanger (81) is supplied to perform cooling and heating.

When increasing the heat radiation of the refrigerant circulating in the refrigerant circuit (20), the control means (200) changes the capacity of the compressor means (40). At this time, the control means (200) sets the capacity of the compressor means (40) to a target value determined based on the difference between the detected temperature of the room temperature detecting means (84) and the set temperature input by the user or the like. Next, the capacity of the compressor means (40) is adjusted.

In the sixth solution, when increasing the heat radiation of the refrigerant circulating in the refrigerant circuit (20), the control means (200) controls the capacity of the compressor means (40) and the air-conditioning heat exchanger (81). ) Or the amount of air to the cooling only heat exchanger (91). At that time, the control means (200) sets a priority order as to which of the three manipulated variables is to be changed, and determines the capacity of the compressor means (40) and the capacity of the air conditioning heat exchanger (81). Change the air volume and the air volume to the cooling heat exchanger (91) in this order.

Specifically, when increasing the amount of heat released from the refrigerant circulating in the refrigerant circuit (20), the control means (200) changes the capacity of the compressor means (40) with the highest priority. However, in some cases, the capacity of the compressor means (40) cannot be changed. For example, if the capacity of the compressor means (40) is already at its maximum, it is no longer possible to increase the capacity of the compressor means (40). In such a case, the control means (200)
Change the air flow to the air-conditioning heat exchanger (81). However, in some cases, the amount of air blown to the air-conditioning heat exchanger (81) cannot be changed. For example, if the amount of air blown to the air-conditioning heat exchanger (81) is already the maximum, the amount of air blown to the air-conditioning heat exchanger (81) can no longer be increased. In such a case, the control means (200) controls the heat exchanger (9
Change the air flow to 1).

In the seventh means, the refrigerant circuit (20)
Control means (20)
0) controls the amount of air blown to the cooling-specific heat exchanger (91), the amount of air blown to the air-conditioning heat exchanger (81), or the capacity of the compressor means (40). At this time, the control means (200)
Priorities are set as to which of the two manipulated variables is to be changed. The amount of air blown to the heat exchanger exclusively for cooling (91), the amount of air blown to the heat exchanger for air conditioning (81), and the compressor means (40 ) In order of capacity.

Specifically, when reducing the amount of heat radiated from the refrigerant circulating in the refrigerant circuit (20), the control means (200) changes the amount of air blown to the cooling only heat exchanger (91) with the highest priority. However, in some cases, the amount of air blown to the cooling-specific heat exchanger (91) cannot be changed. For example, if the airflow to the cooling only heat exchanger (91) is already at a minimum, the airflow to the cooling only heat exchanger (91) can no longer be reduced. In such a case, the control means (200) changes the amount of air blown to the air-conditioning heat exchanger (81). However, in some cases, the amount of air blown to the air-conditioning heat exchanger (81) cannot be changed. For example, if the airflow to the air conditioning heat exchanger (81) is already at a minimum, the air conditioning heat exchanger (81)
It is not possible to reduce the amount of air blown to the air. In such a case,
The control means (200) changes the capacity of the compressor means (40).

[0034] In the eighth solution, a ventilation blower (87) is provided in the refrigerating apparatus. This ventilation blower (87)
Is operated, outside air is introduced into the room. In this solution, the control means (200) increases or decreases the capacity of the compressor means (40), the amount of air blown to the air-conditioning heat exchanger (81), or the amount of air blown to the ventilation blower (87). Control means (200)
By adjusting these, the amount of heat radiation and the amount of heat absorbed by the refrigerant circulating in the refrigerant circuit (20) are increased or decreased to balance the two.

For example, a ventilation fan (87) for heating operation
When the amount of air blown is increased, the indoor temperature decreases, the heating load increases, and the amount of heat released from the refrigerant in the air-conditioning heat exchanger (81) increases. Conversely, if the amount of air blown by the ventilation blower (87) is reduced during the heating operation, the indoor temperature rises, the heating load decreases, and the amount of refrigerant radiated by the air-conditioning heat exchanger (81) decreases.

[0036]

According to the first solution, the control means (20
In 0), a target value for controlling the capacity of the compressor means (40) is determined based on two parameters, and the capacity of the compressor means (40) is set to be the smaller of the two target values. Adjust. Therefore, according to the present solution, the compressor means (40) can be operated with a smaller capacity than when the capacity of the compressor means (40) is adjusted based on one parameter. As a result, the energy for driving the compressors (41, 42) of the compressor means (40), that is, the energy required for operating the refrigeration system can be reduced, and the user who wants to prioritize the reduction of the energy consumption of the refrigeration system can be reduced. We can respond to requests.

In the second solution, the refrigerant circulating in the refrigerant circuit (20) during the heating operation absorbs heat in the refrigeration heat exchanger (101) and releases heat in the air conditioning heat exchanger (81).
That is, the heat that the refrigerant has absorbed from the air in the refrigerator in the refrigeration heat exchanger (101) is dissipated in the air conditioning heat exchanger (81) and used for indoor heating. Therefore, according to the present solution, the heat conventionally thrown into the outdoor air can be used for heating the room, and the energy required for operating the refrigeration apparatus can be further reduced.

In the third solution, the refrigerant circulating in the refrigerant circuit (20) during the heating operation absorbs heat in the refrigeration heat exchanger (101) and releases heat in the air conditioning heat exchanger (81).
That is, the heat that the refrigerant has absorbed from the air in the refrigerator in the refrigeration heat exchanger (101) is dissipated in the air conditioning heat exchanger (81) and used for indoor heating. Therefore, according to the present solution, the heat that has been conventionally thrown into the outdoor air can be recovered and used for heating the room, and the energy required for operating the refrigeration apparatus can be reduced.

Further, in the present solution, the heat absorption amount and the heat release amount of the refrigerant circulating in the refrigerant circuit (20) are balanced.
The control means (200) controls the operation of the refrigeration system. For this reason, according to the present solution, the heating operation for recovering and discarding the heat conventionally used for heating can be continued for as long as possible, and the energy required for the operation of the refrigeration apparatus can be reliably reduced. Can be reduced.

In the fourth solution, the refrigerant circuit (20)
Is connected to a cooling-only heat exchanger (91). Therefore, during the heating operation, the heat absorbed by the refrigerant in the cooling-specific heat exchanger (91) can be used for indoor heating. Further, the control amount when the control means (200) controls the operation of the refrigeration apparatus can be specified, and the heating operation can be continued by reliably balancing the amount of heat absorption and the amount of heat release of the refrigerant circulating in the refrigerant circuit (20).

According to the fifth, sixth, and seventh solving means, the operation when the control means (200) increases or decreases the amount of heat release of the refrigerant in the refrigerant circuit (20) can be embodied. And
The amount of refrigerant radiated by the air-conditioning heat exchanger (81) was secured,
Energy consumption of the refrigeration system can be reduced while maintaining the required heating capacity. In particular, in the sixth and seventh solving means, priorities are set for the objects operated by the control means (200) when increasing or decreasing the amount of heat release of the refrigerant in the refrigerant circuit (20). For this reason, it is possible to reduce the energy consumption of the refrigeration apparatus while keeping the indoor comfort during heating as much as possible.

According to the eighth aspect, the amount of heat released from the refrigerant in the refrigerant circuit (20) can be increased or decreased by adjusting the amount of air blown from the ventilation blower (87) provided in the refrigeration system. it can.

[0043]

Embodiments of the present invention will be described below in detail with reference to the drawings. A refrigeration apparatus (10) according to the present embodiment is provided in a convenience store, and performs cooling of a showcase and cooling and heating of a store.

As shown in FIGS. 1 and 2, the refrigeration apparatus (10) according to the present embodiment includes a high-temperature side refrigerant circuit (20), a low-temperature side refrigerant circuit (25), a controller (200), and an operation changeover switch. (250), and is configured to perform a so-called binary refrigeration cycle. In addition, the refrigerating device (10)
Comprises an outdoor unit (11), a first indoor unit (12), a second indoor unit (13), a refrigeration unit (14), a cascade unit (15), a refrigeration unit (16), and a ventilation fan (87). I have.

The first indoor unit (12) is configured to switch between cooling and heating. The first indoor unit (12) is installed at, for example, a sales floor. The second indoor unit (13) is configured to perform only cooling. This second indoor unit (13) is installed in a room having a heat load throughout the year, such as a kitchen, for example,
Only cooling is performed. The refrigeration unit (14) is installed in a refrigerated showcase and cools the air inside the showcase. The refrigeration unit (16) is installed in a refrigeration showcase and cools the air inside the showcase.
The ventilation fan (87) is installed at a sales floor or the like, similarly to the first indoor unit (12). This ventilation fan (87) constitutes a ventilation blower for introducing outside air into a room such as a sales floor.

<< Structure of High Temperature Side Refrigerant Circuit >> The high temperature side refrigerant circuit (20) includes an outdoor circuit (30), first and second indoor circuits (80, 90), a refrigeration circuit (100), Side cascade circuit (110), first and second liquid side communication pipes (21, 23),
The first and second gas side communication pipes (22, 24) are provided. Among these, the first indoor circuit (80) is connected to the outdoor circuit (30) via the first liquid side communication pipe (21) and the first gas side communication pipe (22). On the other hand, the second indoor circuit (9
0), refrigeration circuit (100), and high-temperature cascade circuit (11
0) is connected in parallel to the outdoor circuit (30) via the second liquid side communication pipe (23) and the second gas side communication pipe (24). The high-temperature side refrigerant circuit (20) is filled with a high-temperature side refrigerant.

The outdoor circuit (30) includes an outdoor unit (1).
It is stored in 1). The outdoor circuit (30) includes a compressor unit (40), a four-way switching valve (31), and an outdoor heat exchanger (3
2), the outdoor expansion valve (34), the receiver (33), and the first
And a second liquid-side stop valve (35, 37), and first and second gas-side stop valves (36, 38). The outdoor circuit (3
0) is provided with a degassing pipe (64), a pressure equalizing pipe (66), and a liquid supply pipe (68).

The compressor unit (40) comprises a first compressor (41) and a second compressor (42) connected in parallel, and constitutes compressor means. First and second compressors (4
1,42) are hermetic, high-pressure dome-type scroll compressors. That is, these compressors (41, 42) are configured by housing a compression mechanism and an electric motor that drives the compression mechanism in a cylindrical housing. The illustration of the compression mechanism and the electric motor is omitted. The first compressor (41) has a variable capacity in which the number of revolutions of the electric motor is changed stepwise or continuously. The second compressor (42) is of a constant capacity in which the electric motor is always driven at a constant rotation speed. The capacity of the entire compressor unit (40) is variable by changing the capacity of the first compressor (41) or starting and stopping the second compressor (42).

The compressor unit (40) is provided with a suction pipe (4
3) and a discharge pipe (44). The suction pipe (43)
The inlet end is connected to the first port of the four-way switching valve (31), and the outlet end is branched into two, and each of the compressors (41, 42)
Is connected to the suction side. The discharge pipe (44) has an inlet end branched into two and connected to the discharge side of each compressor (41, 42), and an outlet end connected to the second port of the four-way switching valve (31). Have been. Further, a discharge-side check valve (45) is provided in a branch pipe of the discharge pipe (44) connected to the second compressor (42). The discharge-side check valve (45) allows only the flow of the refrigerant in the direction flowing out of the second compressor (42).

The compressor unit (40) includes an oil separator (51), an oil return pipe (52), and an oil equalizing pipe (54). The oil separator (51) is provided in the middle of the discharge pipe (44). This oil separator (51) is a compressor (41,42)
To separate the refrigerating machine oil from the discharged refrigerant.
The oil return pipe (52) has one end connected to the oil separator (51) and the other end connected to the suction pipe (43). The oil return pipe (52) is for returning the refrigerating machine oil separated by the oil separator (51) to the suction side of the compressors (41, 42), and is provided with an oil return solenoid valve (53). Have. Equalizing oil pipe (54)
Has one end connected to the second compressor (42) and the other end connected to the suction pipe (43) near the suction side of the first compressor (41). This oil equalizing pipe (54) is connected to each compressor (4
This is for averaging the amount of refrigerating machine oil stored in the housing of (1, 42), and includes an oil equalizing solenoid valve (55).

The four-way switching valve (31) has a third port connected to the first gas side shut-off valve (36) by a pipe, and a fourth port.
Port is connected to the upper end of the outdoor heat exchanger (32) by piping. The four-way switching valve (31) has a state in which the first port and the third port are in communication and the second port and the fourth port are in communication (a state indicated by a solid line in FIG. 1); And the fourth port communicates with each other, and the second and third ports communicate with each other (the state shown by the broken line in FIG. 1).

The outdoor heat exchanger (32) is composed of a cross-fin type fin-and-tube heat exchanger. In the outdoor heat exchanger (32), the high-temperature side refrigerant circulating in the high-temperature side refrigerant circuit (20) exchanges heat with the outdoor air.

The receiver (33) is a cylindrical container for storing the refrigerant. The receiver (33) is connected to the outdoor heat exchanger (32) and the first liquid side closing valve (35) via the inflow pipe (60) and the outflow pipe (62).

The inlet end of the inflow pipe (60) is branched into two branch pipes (60a, 60b), and the outlet end is connected to the upper end of the receiver (33). The first branch pipe (60a) of the inflow pipe (60) is connected to the lower end of the outdoor heat exchanger (32). The first branch pipe (60a) is provided with a first inflow check valve (61a). First inflow check valve (61
a) allows only the flow of refrigerant from the outdoor heat exchanger (32) to the receiver (33). The second branch pipe (60b) of the inflow pipe (60) is connected to the first liquid side closing valve (35). This second branch pipe (60b) has a second inflow check valve (61
b) is provided. The second inflow check valve (61b)
Only the flow of the refrigerant from the liquid side closing valve (35) to the receiver (33) is allowed.

The outlet pipe (62) has an inlet end connected to the lower end of the receiver (33), and an outlet end side branched into two branch pipes (62a, 62b). The first branch pipe (62a) of the outflow pipe (62) is connected to the lower end of the outdoor heat exchanger (32). The first branch pipe (62a) is provided with the outdoor expansion valve (34). The second branch pipe (62b) of the outflow pipe (62) is connected to the first liquid side closing valve (35). The second branch pipe (62b) is provided with an outflow check valve (63). Outflow check valve (63), receiver (33)
Only the flow of the refrigerant from to the first liquid side closing valve (35) is allowed.

The second liquid-side stop valve (37) is connected to the outflow pipe (6).
The pipe is connected between the outflow check valve (63) and the receiver (33) in the second branch pipe (62b) of 2). On the other hand, the second gas side stop valve (38) is connected to a suction pipe (43) of the compressor unit (40) by piping.

The gas vent pipe (64) has one end connected to the upper end of the receiver (33) and the other end connected to the suction pipe (4).
3) Connected to. The gas vent pipe (64) is provided with a gas vent solenoid valve (65). When the gas release solenoid valve (65) is opened and closed, the flow of the refrigerant in the gas release pipe (64) is interrupted.

One end of the pressure equalizing pipe (66) is connected to the degassing solenoid valve (65) in the degassing pipe (64) and the receiver (3).
The other end is connected to the discharge pipe (44). Further, the equalizing pipe (66) has a check valve (67) for equalizing that allows only the flow of the refrigerant from one end to the other end.
Is provided.

The first indoor circuit (80) is housed in the first indoor unit (12). This first indoor circuit (80)
Is a first indoor heat exchanger (81) which is a heat exchanger for air conditioning;
The first indoor expansion valve (82) is connected in series with a pipe. The first indoor expansion valve (82) is a first indoor heat exchanger (81).
Is connected to the lower end. The first of the first indoor circuit (80)
The end on the indoor expansion valve (82) side is connected to the first liquid side closing valve (35) of the outdoor circuit (30) via the first liquid side connecting pipe (21). On the other hand, the end of the first indoor circuit (80) on the first indoor heat exchanger (81) side is connected to the first gas side shut-off valve of the outdoor circuit (30) via the first gas side communication pipe (22). Connected to (36).

The second indoor circuit (90) is housed in the second indoor unit (13). This second indoor circuit (90)
Is the second indoor heat exchanger (91) which is a cooling heat exchanger
And a second indoor expansion valve (92) connected in series by piping. The second indoor expansion valve (92) is connected to a lower end of the second indoor heat exchanger (91).

The refrigeration circuit (100) includes a refrigeration unit (1
4) is stored. This refrigeration circuit (100) is configured by connecting a refrigeration heat exchanger (101) and a refrigeration expansion valve (102) in series by piping. The refrigerating expansion valve (102) is connected to the upper end of the refrigerating heat exchanger (101).

The high temperature side cascade circuit (110) is housed in a cascade unit (15). This high-temperature side cascade circuit (110) is a cascade heat exchanger (111)
And a cascade expansion valve (112) connected in series by piping. The cascade expansion valve (112) is connected to an upper end on the primary side of the cascade heat exchanger (111).

As described above, for the outdoor circuit (30), the second liquid side communication pipe (23) and the second gas side communication pipe (24)
, The second indoor circuit (90), the refrigeration circuit (100), and the high-temperature side cascade circuit (110) are connected in parallel with each other.

Specifically, one end of the second liquid side communication pipe (23) is connected to the second liquid side closing valve (37). Also,
The second liquid side communication pipe (23) is branched into three at the other end,
The end of the second indoor circuit (90) on the side of the second indoor expansion valve (92) and the refrigeration expansion valve (102) in the refrigeration circuit (100)
And an end on the cascade expansion valve (112) side of the high temperature side cascade circuit (110).

On the other hand, one end of the second gas side communication pipe (24) is connected to the second gas side closing valve (38). Also,
The second gas-side communication pipe (24) is branched into three at the other end, and is connected to the second indoor heat exchanger (9) in the second indoor circuit (90).
1) The end of the side, the end of the refrigeration heat exchanger (101) in the refrigeration circuit (100), and the end of the high-temperature cascade circuit (110) on the cascade heat exchanger (111) side Have been.

The first and second indoor heat exchangers (81, 91) and the refrigerating heat exchanger (101) are each constituted by a cross-fin type fin-and-tube heat exchanger. First
In the second indoor heat exchanger (81, 91), the high-temperature side refrigerant circuit (2,
Heat exchange between the high-temperature side refrigerant circulating through 0) and the indoor air is performed. In the refrigeration heat exchanger (101), the high-temperature side refrigerant circuit (2
The high-temperature side refrigerant circulating through 0) and the air in the refrigerator exchange heat.

<< Configuration of Low Temperature Refrigerant Circuit >> The low temperature refrigerant circuit (25) includes a low temperature cascade circuit (120), a refrigeration circuit (130), a third liquid side communication pipe (26), It is constituted by a gas side communication pipe (27). The low temperature side cascade circuit (120) and the refrigeration circuit (130) are connected via a third liquid side communication pipe (26) and a third gas side communication pipe (27). The low-temperature side refrigerant circuit (25) is filled with a low-temperature side refrigerant.

The low temperature side cascade circuit (120) is housed in the cascade unit (15). The low-temperature cascade circuit (120) includes a low-temperature compressor (121), a receiver (123), a third liquid-side shutoff valve (124), and a third gas-side shutoff valve (125). 1 and 2, "A" in FIG. 2 corresponds to "A" in FIG. 1, and "B" in FIG. 2 corresponds to "B" in FIG.

The discharge side of the low temperature side compressor (121) is connected to the cascade heat exchanger (11) through a discharge side check valve (122).
This discharge-side check valve (122), which is connected to the upper end of the secondary side in (1), allows only the flow of refrigerant from the low-temperature side compressor (121) to the cascade heat exchanger (111). .
On the other hand, the suction side of the low temperature side compressor (121) is connected to the third gas side closing valve (125) by piping. The lower end of the secondary side of the cascade heat exchanger (111) is connected to the upper part of the receiver (123) by piping. The bottom of the receiver (123) is connected to the third liquid-side stop valve (124) by piping.

The refrigeration circuit (130) includes a refrigeration unit (1
6) is stored. The refrigeration circuit (130) is configured by connecting a refrigeration heat exchanger (131) and a refrigeration expansion valve (132) in series with a pipe. The refrigeration expansion valve (132) is connected to the upper end of the refrigeration heat exchanger (131). The end of the refrigeration circuit (130) on the side of the refrigeration expansion valve (132) is connected to the third liquid side shut-off valve (124) of the low temperature side cascade circuit (120) via the third liquid side communication pipe (26). It is connected. On the other hand, the end of the refrigeration circuit (130) on the refrigeration heat exchanger (131) side is the third end.
The gas side communication pipe (27) is connected to the third gas side shutoff valve (125) of the low temperature side cascade circuit (120).

The cascade heat exchanger (111) is constituted by a plate heat exchanger. The cascade heat exchanger (111) has a primary flow path and a secondary flow path defined therein. As described above, the cascade heat exchanger (111) has a primary side connected to the high-temperature side refrigerant circuit (20) and a secondary side connected to the low-temperature side refrigerant circuit (25). The cascade heat exchanger (111) is for exchanging heat between the high-temperature side refrigerant flowing through its primary side and the low-temperature side refrigerant flowing through its secondary side. That is, the cascade heat exchanger (111) functions as a cascade condenser in the binary refrigeration cycle.

<< Other Configuration >> The outdoor unit (11)
Is provided with an outdoor fan (70) and an outside air temperature sensor (71). The outdoor fan (70) is an outdoor heat exchanger (32)
It is for sending outdoor air to Outside temperature sensor (7
1) is for detecting the temperature of the outdoor air sent to the outdoor heat exchanger (32).

The outdoor circuit (30) housed in the outdoor unit (11) is provided with various sensors. Specifically, the outdoor heat exchanger (32) is provided with an outdoor heat exchanger temperature sensor (72) for detecting the heat transfer tube temperature. The suction pipe (43) has a suction pipe temperature sensor (73) for detecting the suction refrigerant temperature of the compressor (41, 42) and a low pressure for detecting the suction refrigerant pressure of the compressor (41, 42). A pressure sensor (74) is provided. This low pressure sensor (74) constitutes low pressure detection means. The discharge pipe (44) has a discharge pipe temperature sensor (75) for detecting the refrigerant temperature discharged from the compressor (41, 42) and a compressor (41, 42).
Pressure sensor (76) for detecting the refrigerant pressure discharged from
And a high-pressure switch (77). The degassing pipe (64) has a degassing pipe temperature sensor (7) for detecting the refrigerant temperature after passing through the degassing solenoid valve (65).
8) is provided.

The first indoor unit (12) is provided with a first indoor fan (83) and a first internal temperature sensor (84). The first indoor fan (83) is for sending indoor air to the first indoor heat exchanger (81). The first internal air temperature sensor (84) is for detecting the temperature of the indoor air sent to the first indoor heat exchanger (81), and constitutes an indoor air temperature detecting means.

The first indoor circuit (80) housed in the first indoor unit (12) is provided with a temperature sensor. Specifically, the first indoor heat exchanger (81) is provided with a first indoor heat exchanger temperature sensor (85) for detecting the heat transfer tube temperature. Near the upper end of the first indoor heat exchanger (81) in the first indoor circuit (80), a first gas side temperature sensor (86) for detecting the temperature of the gas refrigerant flowing through the first indoor circuit (80) is provided. Is provided.

The second indoor unit (13) is provided with a second indoor fan (93) and a second internal temperature sensor (94). The second indoor fan (93) is for sending indoor air to the second indoor heat exchanger (91). The second inside air temperature sensor (94) is for detecting the temperature of room air sent to the second indoor heat exchanger (91).

The second indoor circuit (90) housed in the second indoor unit (13) is provided with a temperature sensor. Specifically, the second indoor heat exchanger (91) is provided with a second indoor heat exchanger temperature sensor (95) for detecting the heat transfer tube temperature. Near the upper end of the second indoor heat exchanger (91) in the second indoor circuit (90), a second gas side temperature sensor (96) for detecting the temperature of the gas refrigerant flowing through the second indoor circuit (90). Is provided.

The refrigeration unit (14) is provided with a refrigeration fan (103) and a refrigeration temperature sensor (104). The refrigeration fan (103) is for sending air in the refrigerator to the refrigeration heat exchanger (101). The refrigeration temperature sensor (104) is for detecting the temperature of the inside air sent to the refrigeration heat exchanger (101).

The refrigeration circuit (100) housed in the refrigeration unit (14) is provided with a temperature sensor. Specifically, the refrigerating heat exchanger (101) is provided with a refrigerating heat exchanger temperature sensor (105) for detecting the heat transfer tube temperature. A refrigeration gas side temperature sensor (106) for detecting the temperature of the gas refrigerant flowing through the refrigeration circuit (100) is provided near the lower end of the refrigeration heat exchanger (101) in the refrigeration circuit (100).

The high temperature side cascade circuit (110) housed in the cascade unit (15) is provided with a cascade outflow side temperature sensor (113). The cascade outlet temperature sensor (113) is connected to the cascade heat exchanger (1).
This is for detecting the temperature of the high-temperature side refrigerant flowing out from the primary side in 11).

The refrigeration unit (16) is provided with a refrigeration fan (133) and a refrigeration temperature sensor (134). The freezing fan (133) is for sending air in the freezer to the freezing heat exchanger (131). The refrigeration temperature sensor (134) is for detecting the temperature of the air in the refrigerator sent to the refrigeration heat exchanger (131).

The refrigeration circuit (130) housed in the refrigeration unit (16) is provided with a temperature sensor. Specifically, the refrigeration heat exchanger (131) is provided with a refrigeration heat exchanger temperature sensor (135) for detecting the heat transfer tube temperature. A refrigeration gas side temperature sensor (136) for detecting the temperature of the gas refrigerant flowing through the refrigeration circuit (130) is provided near the lower end of the refrigeration heat exchanger (131) in the refrigeration circuit (130).

The controller (200) controls the operation of the refrigeration system (10) in response to detection signals from the various sensors and the like, and constitutes control means. For example, the controller (200) controls the opening degree of the outdoor expansion valve (34), the switching operation of the four-way switching valve (31), the capacity adjustment of the compressor unit (40), and the air volume adjustment of the outdoor fan (70). And so on. In addition, the controller (200) is configured to be able to execute energy saving priority control that gives top priority to energy saving, and energy saving heating priority control that secures heating performance during heating while saving energy. The controller (200) is housed in the outdoor unit (11).

The operation changeover switch (250) is for inputting an external signal for selecting a control operation to be executed by the controller (200). In other words, by operating the operation changeover switch (250), the controller (20
The control operation to be performed in 0) is arbitrarily selected. The operation changeover switch (250) is housed in the outdoor unit (11).

-Operation-During operation of the refrigeration system (10), the refrigerant circulates in each of the high-temperature side refrigerant circuit (20) and the low-temperature side refrigerant circuit (25) while undergoing a phase change. Is performed. In addition, the refrigeration system (10)
Cooling operation for cooling indoor air with the indoor unit (12);
The first indoor unit (12) switches between a heating operation for heating indoor air and a heating operation.

<< Cooling Operation >> In the cooling operation, in the high-temperature side refrigerant circuit (20), the outdoor heat exchanger (32) is used as a condenser, and the first indoor heat exchanger (81) and the second indoor heat exchanger ( 9
1), a refrigeration cycle is performed using the refrigerating heat exchanger (101) and the cascade heat exchanger (111) as evaporators. On the other hand, in the low-temperature side refrigerant circuit (25), a refrigeration cycle is performed using the cascade heat exchanger (111) as a condenser and the refrigeration heat exchanger (131) as an evaporator.

During the cooling operation, the four-way switching valve (31) is switched to the state shown by the solid line in FIG. Further, the first indoor expansion valve (82), the second indoor expansion valve (92), the refrigeration expansion valve (102), the cascade expansion valve (112), and the refrigeration expansion valve (132) have a predetermined opening degree. The outdoor expansion valve (34) is fully closed. Oil return solenoid valve (53), oil equalizing solenoid valve (55),
The degassing solenoid valve (65) and the liquid supply solenoid valve (69) are normally kept closed, but are opened and closed as needed.

First, the operation in the high-temperature side refrigerant circuit (20) will be described. Compressor (41,42) of compressor unit (40)
Is operated, the high-temperature side refrigerant compressed by the compressors (41, 42) is discharged to the discharge pipe (44). The high-temperature side refrigerant flows into the outdoor heat exchanger (32) through the four-way switching valve (31). In the outdoor heat exchanger (32), the high-temperature side refrigerant releases heat to outdoor air and condenses. The high-temperature side refrigerant condensed in the outdoor heat exchanger (32) flows into the first branch pipe (60a) of the inflow pipe (60), passes through the first inflow check valve (61a), and passes through the receiver (3).
3). The high-temperature side refrigerant of the receiver (33) flows into the outflow pipe (62). Thereafter, the high-temperature side refrigerant is divided into two flows, one of which flows through the outflow check valve (63) to the first liquid side closing valve (35), and the other flows to the second liquid side closing valve (37).

The high-temperature side refrigerant that has passed through the first liquid side shut-off valve (35) passes through the first liquid side communication pipe (21) and passes through the first indoor circuit (8).
0). In the first indoor circuit (80), after the inflowing high-temperature side refrigerant is decompressed by the first indoor expansion valve (82),
It flows into the indoor heat exchanger (81). The first indoor heat exchanger (8
In 1), the high temperature side refrigerant absorbs heat from room air and evaporates. That is, in the first indoor heat exchanger (81), the indoor air is cooled. The high-temperature side refrigerant evaporated in the first indoor heat exchanger (81) flows through the first gas side communication pipe (22), passes through the first gas side shutoff valve (36), and flows into the outdoor circuit (30). . Thereafter, the high-temperature side refrigerant passes through the four-way switching valve (31) and flows into the suction pipe (43).

The high-temperature side refrigerant that has passed through the second liquid side closing valve (37) flows into the second liquid side communication pipe (23). The high-temperature side refrigerant is then divided into three parts, and is divided into the second indoor circuit (9).
0), refrigeration circuit (100), or high-temperature cascade circuit (11
Flows to 0).

The high-temperature side refrigerant flowing into the second indoor circuit (90) flows into the second indoor heat exchanger (91) after being decompressed by the second indoor expansion valve (92). In the second indoor heat exchanger (91), the high-temperature side refrigerant absorbs heat from room air and evaporates. That is, in the second indoor heat exchanger (91), the indoor air is cooled.

The high-temperature side refrigerant flowing into the refrigeration circuit (100) is depressurized by the refrigeration expansion valve (102), and then flows into the refrigeration heat exchanger (101). In the refrigeration heat exchanger (101),
The high temperature side refrigerant absorbs heat from the air inside the refrigerator and evaporates.
That is, in the refrigerating heat exchanger (101), the air in the refrigerator is cooled.

The high-temperature side refrigerant flowing into the high-temperature side cascade circuit (110) is depressurized by the cascade expansion valve (112) and then flows into the cascade heat exchanger (111). In the cascade heat exchanger (111), the high-temperature side refrigerant flowing on the primary side absorbs heat from the low-temperature side refrigerant flowing on the secondary side and evaporates.

The second indoor heat exchanger (91), the refrigeration circuit (10
0) or the high-temperature side refrigerant evaporated in the cascade heat exchanger (111) flows into the second gas side communication pipe (24) and merges, and then passes through the second gas side shutoff valve (38). And flows into the suction pipe (43). In the suction pipe (43), the high temperature side refrigerant sent through the first gas side communication pipe (22)
The high-temperature side refrigerant sent through the second gas side communication pipe (24) merges. The high-temperature side refrigerant flowing through the suction pipe (43)
It is sucked into the compressors (41, 42) of the compressor unit (40). These compressors (41, 42) compress the sucked high-temperature side refrigerant and discharge it again. In the high-temperature side refrigerant circuit (20), such circulation of the high-temperature side refrigerant is repeated.

Next, the operation of the low temperature side refrigerant circuit (25) will be described. When the low temperature side compressor (121) is operated, the compressed low temperature side refrigerant is discharged from the low temperature side compressor (121). This low-temperature side refrigerant flows into the secondary side of the cascade heat exchanger (111) through the discharge side check valve (122). In the cascade heat exchanger (111), the low-temperature side refrigerant on the secondary side releases heat to the high-temperature side refrigerant on the primary side and condenses. The low-temperature side refrigerant condensed in the cascade heat exchanger (111) flows into the receiver (123). Thereafter, the low-temperature side refrigerant flows out of the receiver (123), passes through the third liquid side communication pipe (26), and flows through the refrigeration circuit (13).
0).

In the refrigeration circuit (130), the inflowing low-temperature side refrigerant is reduced in pressure by the refrigeration expansion valve (132), and then flows into the refrigeration heat exchanger (131). In the refrigeration heat exchanger (131),
The low-temperature refrigerant absorbs heat from the air in the freezer and evaporates.
That is, in the freezing heat exchanger (131), the air in the freezer is cooled. The low-temperature side refrigerant evaporated in the refrigeration heat exchanger (131) flows into the low-temperature side cascade circuit (120) through the third gas-side communication pipe (27). Thereafter, the low-temperature side refrigerant is sucked into the low-temperature side compressor (121). The low temperature side compressor (121) compresses the sucked low temperature side refrigerant and discharges it again. In the low-temperature side refrigerant circuit (25), such circulation of the low-temperature side refrigerant is repeated.

<< Heating Operation >> In the heating operation, in the high-temperature side refrigerant circuit (20), the first indoor heat exchanger (81) is used as a condenser, the second indoor heat exchanger (91), and the refrigeration heat exchanger are used. (Ten
1) and a refrigeration cycle is performed using the cascade heat exchanger (111) as an evaporator. In other words, during the heating operation,
No refrigerant flows into the outdoor heat exchanger (32). On the other hand, in the low-temperature side refrigerant circuit (25), a refrigeration cycle is performed using the cascade heat exchanger (111) as a condenser and the refrigeration heat exchanger (131) as an evaporator. The operation of the low-temperature side refrigerant circuit (25) is the same as that in the cooling operation.

At the time of this heating operation, the four-way switching valve (31) is switched to the state shown by the broken line in FIG. Further, the first indoor expansion valve (82), the second indoor expansion valve (92), the refrigeration expansion valve (102), the cascade expansion valve (112), and the refrigeration expansion valve (132) have a predetermined opening degree. The outdoor expansion valve (34) is fully closed. Oil return solenoid valve (53), oil equalizing solenoid valve (55),
The degassing solenoid valve (65) and the liquid supply solenoid valve (69) are normally kept closed, but are opened and closed as needed.

The compressor (41, 42) of the compressor unit (40)
When the compressor is operated, the compressed high-temperature refrigerant flows into the compressor (41, 4
Discharged from 2) to the discharge pipe (44). The discharged high-temperature side refrigerant passes through the four-way switching valve (31), and flows into the first indoor circuit (80) through the first gas side communication pipe (22). The high-temperature side refrigerant that has flowed into the first indoor circuit (80) releases heat to indoor air in the first indoor heat exchanger (81) and condenses. In the first indoor heat exchanger (81), the indoor air is heated by heat radiation of the high-temperature side refrigerant.

The high-temperature side refrigerant condensed in the first indoor heat exchanger (81) passes through the first indoor expansion valve (82) and flows through the first liquid side communication pipe (21). The high-temperature side refrigerant of the first liquid side communication pipe (21) passes through the first liquid side closing valve (35), and flows into the second branch pipe (60b) of the inflow pipe (60). This high temperature side refrigerant is
It flows into the receiver (33) through the inflow check valve (61b). The high-temperature side refrigerant of the receiver (33) flows from the receiver (33) into the outflow pipe (62).

Thereafter, the high temperature side refrigerant flows into the second branch pipe (62b) of the outflow pipe (62) and flows in the same manner as in the cooling operation. That is, the high-temperature side refrigerant is divided and sent to the second indoor circuit (90), the refrigeration circuit (100), or the high-temperature side cascade circuit (110). The high-temperature side refrigerant flowing into the second indoor circuit (90) absorbs heat from indoor air in the second indoor heat exchanger (91) and evaporates. The high-temperature side refrigerant that has flowed into the refrigeration circuit (100) absorbs heat from the internal air in the refrigeration heat exchanger (101) and evaporates. The high-temperature side refrigerant that has flowed into the high-temperature side cascade circuit (110) absorbs heat from the internal air in the cascade heat exchanger (111) and evaporates. The high-temperature side refrigerant evaporated in the second indoor heat exchanger (91), the refrigeration heat exchanger (101), or the cascade heat exchanger (111) merges in the second gas-side communication pipe (24), and After passing through the gas side shut-off valve (38), the suction pipe (4
3).

The high-temperature side refrigerant flowing through the suction pipe (43) is sucked into the compressors (41, 42) of the compressor unit (40). These compressors (41, 42) compress the sucked high-temperature side refrigerant and discharge it again. In the high-temperature side refrigerant circuit (20), such circulation of the high-temperature side refrigerant is repeated. As described above, during the heating operation, the first indoor heat exchanger (91), the refrigeration heat exchanger (101), or the cascade heat exchanger (111) utilizes the heat absorbed by the high-temperature side refrigerant to make the first heat. The indoor heat exchanger (81) heats the indoor air.

<< Control Operation of Controller >> When the operation changeover switch (250) is operated, a predetermined external signal is input to the controller (200). The controller (200) selects and performs one of the energy saving priority control and the energy saving heating priority control according to the input external signal.

First, the energy saving priority control by the controller (200) will be described. Energy saving priority control is performed during a cooling operation in which the first indoor unit (12) cools indoor air,
This is performed both during the heating operation in which the first indoor unit (12) heats the indoor air.

As shown in FIG. 3, when performing the energy saving priority control during the cooling operation, the controller (200)
At T10, two target values for controlling the capacity of the compressor unit (40) are determined. Specifically, the controller (20
0) determines the target frequency of the alternating current supplied to the first compressor (41) as the target value of the displacement control. The first target frequency Hz1 is determined based on the detected pressure LP of the low pressure sensor (74). On the other hand, the second target frequency Hz2 is determined based on a value (Tr-Tset) obtained by subtracting the set temperature Tset input by the user from the detected temperature Tr of the first internal air temperature sensor (84). And the controller (200)
The obtained two target frequencies Hz1 and Hz2 are compared, and the frequency of the alternating current supplied to the first compressor (41) is set to the smaller value of the two target frequencies Hz1 and Hz2.

As shown in FIG. 4, when performing the energy saving priority control during the heating operation, the controller (200) executes
At T11, two target values for controlling the capacity of the compressor unit (40) are determined. Specifically, the controller (20
0) determines the target frequency of the alternating current supplied to the first compressor (41) as the target value of the displacement control. The first target frequency Hz1 is determined based on the detected pressure LP of the low pressure sensor (74). On the other hand, the second target frequency Hz2 is determined based on a value (Tset-Tr) obtained by subtracting the detected temperature Tr of the first internal temperature sensor (84) from the set temperature Tset input by the user. And the controller (200)
The obtained two target frequencies Hz1 and Hz2 are compared, and the frequency of the alternating current supplied to the first compressor (41) is set to the smaller value of the two target frequencies Hz1 and Hz2.

Next, the energy saving heating priority control by the controller (200) will be described. The energy-saving heating priority control is performed during a heating operation in which room air is heated by the first indoor heat exchanger (81) using heat absorbed by the refrigerant in the second indoor heat exchanger (91) and the like. The energy saving heating priority control is a control for keeping the heating operation as long as possible while ensuring the heating capacity of the first indoor unit (12).

As shown in FIG. 5, the controller (200)
Determines in step ST20 whether or not a value (Tset-Tr) obtained by subtracting the detection temperature Tr of the first internal air temperature sensor (84) from the set temperature Tset input by the user is 0.5 ° C. or less. The value of 0.5 ° C. is an example.

In step ST20, when the value of (Tset−Tr) is 0.5 ° C. or less, the indoor temperature is substantially equal to the set temperature Ts.
et has been reached, and the heat radiation amount of the refrigerant in the first indoor heat exchanger (81) is sufficient for the heating load. In this case, the controller (200) moves to Step ST21.

In step ST21, the controller (20
0) decreases the rotation speed of the second indoor fan (93), the rotation speed of the first indoor fan (83), or the rotation speed of the first compressor (41). At this time, the priority order is set for the target whose rotation speed is reduced by the controller (200).

Specifically, in step ST21, the controller (200) lowers the rotational speed of the second indoor fan (93) most preferentially. When the rotation speed of the second indoor fan (93) decreases, the amount of air blown to the second indoor heat exchanger (91) decreases, and the amount of heat absorbed by the refrigerant in the second indoor heat exchanger (91) decreases. When the amount of heat absorbed by the refrigerant in the second indoor heat exchanger (91) decreases, the amount of heat released by the refrigerant in the first indoor heat exchanger (81) decreases accordingly.

However, when the rotation speed of the second indoor fan (93) is already at the minimum at the time of moving to step ST21, the rotation speed of the second indoor fan (93) can no longer be reduced. In such a case, the controller (200)
Reduces the rotation speed of the first indoor fan (83). That is, the controller (200) lowers the rotation speed of the first indoor fan (83) in preference to the rotation speed of the first compressor (41). When the rotation speed of the first indoor fan (83) decreases,
The amount of air blown to the first indoor heat exchanger (81) decreases. Then, when the amount of air blown to the first indoor heat exchanger (81) decreases,
The heat radiation amount of the refrigerant in the first indoor heat exchanger (81) decreases.

However, if the rotational speeds of the second indoor fan (93) and the first indoor fan (83) are already at the minimum at the time of moving to step ST21, the second indoor fan (9)
3) and the rotation speed of the first indoor fan (83) cannot be reduced. In such a case, the controller (200) lowers the frequency of the alternating current supplied to the first compressor (41) to lower the rotation speed of the first compressor (41), and the compressor unit (40)
Reduce the capacity of When the capacity of the compressor unit (40) decreases, the circulation amount of the refrigerant in the refrigerant circuit (20) decreases, and the heat release amount of the refrigerant in the first indoor heat exchanger (81) decreases.

In step ST20, (Tset−T
When the value of r) exceeds 0.5 ° C., the indoor air temperature Tr is lower than the set temperature Tset, and the heat release amount of the refrigerant in the first indoor heat exchanger (81) is insufficient for the heating load. In this case, the controller (200) moves to Step ST22.

In step ST22, the controller (20
(0) determines a target value for displacement control of the compressor unit (40) based on the value of (Tset-Tr). Specifically, the controller (200) determines a target frequency Hz of the alternating current supplied to the first compressor (41) as a target value of the displacement control.

Then, the process proceeds to step ST23, where it is determined whether or not the set target frequency Hz exceeds 200 Hz. Here, in the present embodiment, the maximum frequency of the alternating current supplied to the first compressor (41) is 200 Hz. In addition, this 200Hz
Is an example.

In step ST23, the target frequency Hz is 2
If it is equal to or lower than 00 Hz, the frequency of the alternating current supplied to the first compressor (41) can be set as the target frequency Hz. Then, the controller (200) moves to step ST25,
The frequency of the alternating current supplied to the first compressor (41) is set to the target frequency Hz, and the rotation speed of the first compressor (41) is increased to increase the capacity of the compressor unit (40).

On the other hand, in step ST23, the target frequency H
If z exceeds 200Hz, it is no longer the first compressor (41)
It is impossible to set the frequency of the alternating current supplied to the target frequency Hz. In this case, the controller (200)
Moving to step ST24, the number of revolutions of the first indoor fan (83)
Alternatively, the rotation speed of the second indoor fan (93) is increased. At this time, the priority is given to the objects for which the controller (200) increases the rotation speed.

Specifically, in step ST24, the controller (200) first increases the rotation speed of the first indoor fan (83). That is, the controller (200)
The rotation speed of the indoor fan (83) is increased with priority over the rotation speed of the second indoor fan (93). The first indoor fan (83)
When the rotation speed of the air conditioner increases, the amount of air blown to the first indoor heat exchanger (81) increases. When the amount of air blown to the first indoor heat exchanger (81) increases, the amount of heat released from the refrigerant in the first indoor heat exchanger (81) increases.

However, when the rotational speed of the first indoor fan (83) is already at the maximum at the time of moving to step ST24, the rotational speed of the first indoor fan (83) can no longer be increased. In such a case, the controller (200)
Increases the rotation speed of the second indoor fan (93) to increase the amount of air blown to the second indoor heat exchanger (91). When the amount of air blown to the second indoor heat exchanger (91) increases, the amount of heat absorbed by the refrigerant in the second indoor heat exchanger (91) increases, and accordingly, the amount of refrigerant in the first indoor heat exchanger (81) increases. The amount of heat radiation increases.

-Effects of Embodiment- In this embodiment, in the energy saving priority operation of the controller (200), the target frequency for controlling the capacity of the compressor unit (40) is determined based on two parameters, and the two target frequencies are determined. An alternating current of the smaller frequency of the frequencies Hz1 and Hz2 is supplied to the first compressor (41). Therefore, according to the present embodiment, the first compressor (4
1st compressor (41)
Can be operated at a low rotation speed. As a result, the first
The power required to drive the compressor (41), that is, the power required to operate the refrigeration apparatus, can be reduced, and it is possible to meet the user's desire to prioritize the reduction in power consumption of the refrigeration apparatus.

In the heating operation of this embodiment,
The refrigerant circulating in the refrigerant circuit (20) absorbs heat in the second indoor heat exchanger (91), the refrigeration heat exchanger (101), and the cascade heat exchanger (111), and absorbs heat in the first indoor heat exchanger (81). ) To dissipate heat. That is, the heat absorbed by the refrigerant in the second indoor heat exchanger (91) and the like is radiated in the first indoor heat exchanger (81) and used for indoor heating. Therefore, according to the present embodiment, the heat that has been conventionally dumped into the outdoor air can be used for indoor heating, and the power consumption of the refrigeration apparatus can be further reduced.

In this embodiment, the controller (20
In the energy saving heating priority operation of 0), the amount of heat absorption and the amount of heat release of the refrigerant circulating in the refrigerant circuit (20) during the heating operation are balanced. For this reason, the heating operation of recovering and discarding heat that is conventionally used for heating can be continued for as long as possible. Therefore, according to the present embodiment, it is possible to reliably reduce the power consumption of the refrigeration apparatus during the heating operation while securing the heating capacity of the first indoor unit (12).

-Modification of Embodiment- As described above, in the above embodiment, the controller (20
In the energy saving heating priority operation of (0), when (Tset−Tr) exceeds 0.5 ° C. and the target frequency Hz exceeds 200 Hz, the rotation speed of the first indoor fan (83) or the second indoor fan ( 93) is increased (see step ST24 in FIG. 5). On the other hand, in step ST24 of FIG. 5, not only the rotation speed of the first indoor fan (83) and the second indoor fan (93) but also the rotation speed of the ventilation fan (87) may be increased. If the ventilation volume of the ventilation fan (87) is increased during the heating operation, the indoor temperature decreases and the heating load increases,
The heat radiation amount of the refrigerant in the first indoor heat exchanger (81) increases.

[0125]

In the above embodiment, the second indoor unit (13) for performing only cooling is provided, and the second indoor circuit (90) is connected to the high-temperature side refrigerant circuit (20).
On the other hand, if there is no room in the installation location of the refrigeration system (10) that requires cooling even in winter, the second indoor unit (13) dedicated to cooling may be omitted. In this case, since the second indoor fan (93) does not exist, the rotation speed control of the second indoor fan (93) by the controller (200) is not performed.

[Brief description of the drawings]

FIG. 1 is a piping diagram showing a high-temperature side refrigerant circuit and a part of a low-temperature side refrigerant circuit of a refrigeration apparatus according to an embodiment.

FIG. 2 is a piping system diagram showing a portion not shown in FIG. 1 of the low-temperature side refrigerant circuit according to the embodiment.

FIG. 3 is a flowchart showing the content of energy saving priority control during cooling operation.

FIG. 4 is a flowchart showing the content of energy saving priority control during a heating operation.

FIG. 5 is a flowchart showing the contents of energy saving heating priority control.

[Explanation of symbols]

 (20) High-temperature side refrigerant circuit (refrigerant circuit) (40) Compressor unit (compressor means) (41) First compressor (42) Second compressor (74) Low pressure sensor (low pressure detector) (81) ) 1st indoor heat exchanger (heat exchanger for air conditioning) (84) 1st internal temperature sensor (room temperature detecting means) (87) Ventilation fan (ventilator for ventilation) (91) 2nd indoor heat exchanger (heat exclusively for cooling) Exchanger) (101) Refrigeration heat exchanger (200) Controller (control means)

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Kenji Tanimoto 1304 Kanaokacho, Sakai City, Osaka Daikin Industries, Ltd. Sakai Seisakusho Kanaoka Plant F-term (reference) 3L061 BE02 BF02 BF08

Claims (8)

[Claims] 1. A refrigeration apparatus for performing a refrigeration cycle by circulating a refrigerant in a refrigerant circuit (20), wherein the refrigerant circuit (20) includes at least one compressor (4).
1,42), a variable capacity compressor means (40), an air-conditioning heat exchanger (81) for producing conditioned air for cooling and heating, and cooling air to be supplied to the refrigerator compartment. A low-pressure pressure detecting means (74) for detecting a low-pressure pressure of the refrigerant in the refrigerant circuit (20), while being connected to a refrigeration heat exchanger (101) for producing the air-conditioning heat exchanger (101). The capacity of the indoor air temperature detecting means (84) for detecting the indoor air temperature to which the conditioned air generated in 81) is supplied, and the capacity of the compressor means (40) are determined based on the detected pressure of the low pressure pressure detecting means (74). Control means (200) for adjusting to a smaller one of the target value set in advance or the target value set based on the difference between the detected temperature of the room temperature detecting means (84) and the input set temperature. Refrigeration equipment. 2. The refrigeration system according to claim 1, wherein the refrigerant is condensed and refrigerated by the air-conditioning heat exchanger (81) during the heating operation in which the air-conditioning heat exchanger (81) generates conditioned air for heating. Refrigeration system that performs a refrigeration cycle by evaporating a refrigerant in a heat exchanger (101). 3. A refrigeration apparatus for performing a refrigeration cycle by circulating a refrigerant in a refrigerant circuit (20), wherein the refrigerant circuit (20) includes at least one compressor (4).
1,42), a variable capacity compressor means (40), an air-conditioning heat exchanger (81) for producing conditioned air for cooling and heating, and cooling air to be supplied to the refrigerator compartment. A refrigeration heat exchanger (101) is connected to the air conditioning heat exchanger (81) to generate conditioned air for heating in the air conditioning heat exchanger (81). While condensing the refrigerant and evaporating the refrigerant in the refrigeration heat exchanger (101) to perform a refrigeration cycle. A refrigeration system provided with control means (200) for controlling the operation of the refrigeration system. 4. The refrigeration apparatus according to claim 3, wherein the refrigerant circuit (20) is connected to a cooling-specific heat exchanger (91) for generating only conditioned air for cooling, while the control means ( 200) is a refrigerant circuit for heating operation by adjusting the capacity of the compressor means (40), the amount of air blown to the air-conditioning heat exchanger (81), or the amount of air blown to the cooling only heat exchanger (91). (2
A refrigeration apparatus configured to balance the amount of heat absorption and the amount of heat release of the refrigerant in 0). 5. The refrigeration apparatus according to claim 4, further comprising an indoor air temperature detecting means (84) for detecting an indoor air temperature to which the conditioned air generated by the air conditioning heat exchanger (81) is supplied. The means (200) increases the capacity of the compressor means (40) when the amount of heat released from the refrigerant in the refrigerant circuit (20) during the heating operation is increased. Refrigeration apparatus configured to adjust to a target value determined based on the difference between 6. The refrigeration apparatus according to claim 4, wherein the control means (200) increases a capacity of the compressor means (40) when increasing a heat radiation amount of the refrigerant in the refrigerant circuit (20) during the heating operation. In addition to changing the airflow to the air-conditioning heat exchanger (81) and the airflow to the cooling-only heat exchanger (91),
A refrigeration apparatus configured to change the amount of air blown to the air-conditioning heat exchanger (81) in preference to the amount of air blown to the cooling only heat exchanger (91). 7. The refrigeration apparatus according to claim 4, wherein the control means (200) reduces the heat release amount of the refrigerant in the refrigerant circuit (20) at the time of the heating operation when the heat exchanger for cooling only (9).
The air flow to 1) is changed prior to the air flow to the air conditioning heat exchanger (81) and the capacity of the compressor means (40), and the air flow to the air conditioning heat exchanger (81) is changed. Compressor means (4
0) A refrigeration apparatus configured to change the priority in preference to the capacity. 8. The refrigeration apparatus according to claim 3, further comprising a ventilation blower (87) for introducing outside air into a room to which the conditioned air generated by the air conditioning heat exchanger (81) is supplied. The means (200) is provided with the capacity of the compressor means (40), the amount of air blown to the air-conditioning heat exchanger (81), or the air blower (8).
7) A refrigeration apparatus configured to adjust the amount of air blown to balance the amount of heat absorbed and the amount of heat released in the refrigerant circuit (20) during the heating operation.