JP3861912B2 - Refrigeration equipment - Google Patents

Refrigeration equipment Download PDF

Info

Publication number
JP3861912B2
JP3861912B2 JP2005223726A JP2005223726A JP3861912B2 JP 3861912 B2 JP3861912 B2 JP 3861912B2 JP 2005223726 A JP2005223726 A JP 2005223726A JP 2005223726 A JP2005223726 A JP 2005223726A JP 3861912 B2 JP3861912 B2 JP 3861912B2
Authority
JP
Japan
Prior art keywords
supercooling
refrigerant
heat exchanger
circuit
cooling fluid
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
JP2005223726A
Other languages
Japanese (ja)
Other versions
JP2006207990A (en
Inventor
雅章 竹上
巌 篠原
憲治 谷本
東 近藤
覚 阪江
Original Assignee
ダイキン工業株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to JP2004379512 priority Critical
Application filed by ダイキン工業株式会社 filed Critical ダイキン工業株式会社
Priority to JP2005223726A priority patent/JP3861912B2/en
Publication of JP2006207990A publication Critical patent/JP2006207990A/en
Application granted granted Critical
Publication of JP3861912B2 publication Critical patent/JP3861912B2/en
Application status is Expired - Fee Related legal-status Critical
Anticipated expiration legal-status Critical

Links

Images

Description

  The present invention relates to a refrigeration apparatus for supercooling a refrigerant sent from a heat source side device to a usage side device.

  2. Description of the Related Art Conventionally, a first refrigerant circuit having a supercooling heat exchanger and a second refrigerant circuit having a use side heat exchanger and a heat source side compressor are provided, and the second refrigerant in the second refrigerant circuit is heated for supercooling. There is known a refrigeration apparatus that is supercooled through an exchanger to increase the cooling capacity.

  For example, the air conditioner disclosed in Patent Document 1 includes an outdoor unit, an indoor unit, and a supercooling unit. Specifically, the supercooling unit is provided in the middle of a liquid-side connecting pipe that connects the outdoor unit and the indoor unit, and includes a first refrigerant circuit. The supercooling unit performs a refrigeration cycle by circulating the first refrigerant in the first refrigerant circuit, and the second refrigerant of the air conditioner sent from the liquid side communication pipe is used as a heat exchanger for supercooling the first refrigerant circuit. It is configured to cool at. The supercooling unit cools the liquid refrigerant sent from the outdoor unit of the air conditioner to the indoor unit, and reduces the enthalpy of the liquid refrigerant sent to the indoor unit, thereby improving the cooling capacity.

  As described above, the supercooling unit is for assisting a refrigeration apparatus such as an air conditioner to increase its cooling capacity. For this reason, only the supercooling unit is not operated while the refrigeration apparatus is stopped. Further, the supercooling unit is not operated in a state where the refrigeration apparatus operates as a heat pump as in the heating operation of the air conditioner. Thus, in order to determine whether or not to operate the supercooling unit, it is determined from the operating state of the refrigeration apparatus to which the supercooling unit is attached, the outside air temperature, and the like.

Therefore, in the conventional air conditioner disclosed in Patent Document 1, the control unit of the supercooling unit is connected to the control unit of the air conditioner to constitute one control system. A signal indicating the operating state of the air conditioner is input from the control unit of the air conditioner to the control unit of the supercooling unit. And in this supercooling unit, the operation control is performed based on the signal input from the control part of the air conditioner.
Japanese Patent Laid-Open No. 10-185333

  By the way, in the conventional air conditioner (refrigeration apparatus), when the load increases due to an increase in the outside air temperature or the like, it is usual to increase the operating capacity of the compressor of the second refrigerant circuit to ensure the cooling capacity. is there.

  However, when the refrigerant circulation amount is increased in the second refrigerant circuit having a large difference between the high and low pressures of the refrigeration cycle, there is a problem that the input to the compressor is increased and the coefficient of performance is lowered.

  The present invention has been made in view of the above points, and the object of the present invention is to efficiently operate the entire refrigeration apparatus by adjusting the balance of the operating capacity of the compressor between the heat source side and the subcooling. There is to make it.

To achieve the above object, in this invention, when the load of the refrigeration apparatus is increased, thereby increasing large power consumption relating to the cooling fluid circuit (220) without increasing the power consumption relating to the refrigerant circuit (20) I did it.

  Specifically, in the first invention, a refrigerant circuit having a use side heat exchanger (101, 111, 131) and a heat source side compressor (41, 42, 43) and performing a vapor compression refrigeration cycle by circulating the refrigerant ( 20), a cooling fluid circuit (220) having a supercooling heat exchanger (210) and a pump mechanism (221) for conveying the cooling fluid to the supercooling heat exchanger (210). The refrigeration apparatus that supercools the refrigerant supplied to the use side heat exchanger (101, 111, 131) with the cooling fluid in the supercooling heat exchanger (210) is intended.

Then, the refrigeration system includes a power consumption relating to the refrigerant circuit (20), a control means for controlling (240) a power consumption relating to the cooling fluid circuit (220), said control means (240), the When the load increases, the refrigerant circuit (20) is controlled when the power consumption of the cooling fluid circuit (220) is controlled so that the temperature of the refrigerant at the outlet of the supercooling heat exchanger (210) becomes a target value. The target value is set based on the ambient condition of the supercooling heat exchanger (210) so that the power consumption related to the cooling fluid circuit (220) increases without increasing the power consumption related to the cooling fluid circuit (220). Yes.

  According to the above configuration, in the cooling fluid circuit (220), a cooling fluid such as refrigerant or water for supercooling the refrigerant in the refrigerant circuit (20) is supplied to the supercooling heat exchanger (221) by the pump mechanism (221). 210). In the supercooling heat exchanger (210), the refrigerant in the refrigerant circuit (20) exchanges heat with the cooling fluid. In the supercooling heat exchanger (210), the cooling fluid absorbs heat from the refrigerant in the refrigerant circuit (20), and the refrigerant in the refrigerant circuit (20) is cooled.

In the refrigeration apparatus of the present invention, when the load of the refrigeration apparatus is increased, the control means (240) increasing large power consumption of the cooling fluid circuit (220) without increasing the power consumption of the refrigerant circuit (20) Control the operation. For example, the operating capacity of the pump mechanism (221) is increased to increase the power consumption related to the cooling fluid circuit (220). That is, in the cooling fluid circuit (220), the cooling capacity is increased by increasing the work amount of the electric device such as the pump mechanism (221). Thus, without increasing the power consumption (that is, the work amount) of the electrical equipment such as the heat source side compressor (41, 42, 43) in the refrigerant circuit (20), the supercooling heat exchanger (210) Increases cooling capacity. Therefore, even when the load on the refrigeration system increases, the enthalpy of the refrigerant in the refrigerant circuit (20) toward the use side heat exchanger (101, 111, 131) is kept low, and the cooling capacity in the use side heat exchanger (101, 111, 131) is secured. Is done.

Further, according to the above configuration, the control means (240) sets the target value of the refrigerant outlet temperature of the supercooling heat exchanger (210) to the supercooling heat such as the outside air temperature and the refrigerant flow rate of the refrigerant circuit (20). Adjust based on ambient conditions of exchanger (210). That is, the control means (240) grasps the load state of the refrigeration apparatus from the ambient conditions of the supercooling heat exchanger (210), and sets the target value based on the load state. Therefore, when the load is increased, the power consumption of the refrigerant circuit (20) without increasing the power consumption of the cooling fluid circuit (220) is increased large depending on the load.

In a second invention, in the first invention, the ambient condition of the supercooling heat exchanger (210) is the outside air temperature.

  According to the above configuration, the target value of the outlet refrigerant temperature of the supercooling heat exchanger (210) is set based on the outside air temperature. That is, the control means (240) estimates the load state of the refrigeration apparatus based on the outside air temperature, and determines that the load increases when the outside air temperature increases.

According to a third aspect , in the first aspect , the ambient condition of the supercooling heat exchanger (210) is the degree of supercooling of the refrigerant in the refrigerant circuit (20) in the supercooling heat exchanger (210). is there.

  According to the above configuration, the target value of the outlet refrigerant temperature of the supercooling heat exchanger (210) is set based on the degree of refrigerant subcooling in the refrigerant circuit (20). That is, the control means (240) estimates the load state of the refrigeration apparatus based on the degree of supercooling of the refrigerant, and determines that the load increases when the degree of supercooling decreases. In that case, for example, the target value is set low.

In a fourth invention, in the first invention, the ambient condition of the supercooling heat exchanger (210) is a refrigerant flow rate of the refrigerant circuit (20) flowing through the supercooling heat exchanger (210). .

  According to the above configuration, the target value of the outlet refrigerant temperature of the supercooling heat exchanger (210) is set based on the refrigerant flow rate of the supercooling heat exchanger (210). That is, the control means (240) estimates the load state of the refrigeration system based on the refrigerant flow rate of the supercooling heat exchanger (210), and determines that the load increases when the refrigerant flow rate increases. In that case, for example, the target value is set low.

According to a fifth aspect , in the first aspect , the ambient condition of the supercooling heat exchanger (210) supercools the refrigerant in the refrigerant circuit (20) with the supercooling heat exchanger (210). It is a temperature difference of the cooling fluid of the cooling fluid circuit (220) after the pre-cooling and the supercooling.

  According to the above configuration, the target value of the outlet refrigerant temperature of the supercooling heat exchanger (210) is set based on the temperature difference before and after the supercooling of the cooling fluid. That is, the control means (240) estimates the load state of the refrigeration apparatus based on the temperature difference before and after the cooling fluid is supercooled, and determines that the load has increased when the temperature difference becomes smaller. In that case, for example, the target value is set low.

According to a sixth aspect , in the first aspect , the ambient conditions of the supercooling heat exchanger (210) are for cooling the cooling fluid circuit (220) flowing through the supercooling heat exchanger (210). The flow rate of the fluid.

  According to the above configuration, the target value of the outlet refrigerant temperature of the supercooling heat exchanger (210) is set based on the flow rate of the cooling fluid of the supercooling heat exchanger (210). That is, the control means (240) estimates the load state of the refrigeration apparatus based on the flow rate of the cooling fluid, and determines that the load has increased when the flow rate increases. In that case, for example, the target value is set low.

In a seventh aspect based on the first aspect , the cooling fluid circuit includes a supercooling compressor (221) as a pump mechanism and a heat source side heat exchanger (222), and serves as a cooling fluid. This is a supercooling refrigerant circuit (220) in which the supercooling refrigerant circulates and performs a vapor compression refrigeration cycle. The ambient condition of the supercooling heat exchanger (210) is the high pressure of the supercooling refrigerant in the supercooling refrigerant circuit (220).

  According to the above configuration, the target value of the outlet refrigerant temperature of the supercooling heat exchanger (210) is set based on the high pressure of the supercooling refrigerant of the supercooling refrigerant circuit (220). That is, the control means (240) estimates the load state of the refrigeration apparatus based on the high pressure of the supercooling refrigerant, and determines that the load has increased when the high pressure increases. In that case, for example, the target value is set low.

In an eighth aspect based on the first aspect , the cooling fluid circuit includes a supercooling compressor (221) as a pump mechanism and a heat source side heat exchanger (222), and serves as a cooling fluid. This is a supercooling refrigerant circuit (220) in which the supercooling refrigerant circulates and performs a vapor compression refrigeration cycle. The ambient condition of the supercooling heat exchanger (210) is the pressure difference between the high pressure and the low pressure of the supercooling refrigerant in the supercooling refrigerant circuit (220).

  According to the above configuration, the target value of the outlet refrigerant temperature of the supercooling heat exchanger (210) is set based on the pressure difference between the high pressure and the low pressure of the supercooling refrigerant in the supercooling refrigerant circuit (220). The That is, the control means (240) estimates the load state of the refrigeration apparatus based on the high / low pressure difference of the supercooling refrigerant, and determines that the load has increased when the high / low pressure difference becomes large. In that case, for example, the target value is set low.

In a ninth aspect based on the second aspect , the control means (240) is configured to decrease the target value as the outside air temperature increases.

According to the above configuration, when the outside air temperature increases, the load on the refrigeration apparatus increases. Therefore, even if the target value is not changed, the outlet refrigerant temperature of the supercooling heat exchanger (210) is maintained at the target value. For this purpose, for example, the operating capacity of the pump mechanism (221) must be increased. On the other hand, in the ninth aspect , the control means (240) lowers the target value as the outside air temperature increases. In order to set the outlet refrigerant temperature of the supercooling heat exchanger (210) to a lower target value, the operating capacity of the pump mechanism (221) is further increased, that is, for cooling the pump mechanism (221). There is a need to increase the fluid supply work. Therefore, in this invention, when the load of the refrigerating apparatus by increasing the ambient temperature is increased, the power consumption related to the cooling fluid circuit (220) is increased size by control means (240) adjusts the target value.

  As described above, the endothermic temperature or evaporation temperature of the cooling fluid in the supercooling heat exchanger (210) is higher than the refrigerant evaporation temperature in the use side heat exchanger (101, 111, 131). . The high / low pressure difference of the cooling fluid before and after the pump mechanism (221) of the cooling fluid circuit (220) is smaller than the high / low pressure difference of the refrigeration cycle in the refrigerant circuit (20). The refrigeration apparatus of the present invention does not increase the refrigerant circulation rate in the refrigerant circuit (20) having a large high / low pressure difference, but increases the flow rate of the cooling fluid in the cooling fluid circuit (220) having a smaller high / low pressure difference. As described above, the power consumption (work volume) of the pump mechanism (221) and the like is increased to preferentially increase the power consumption related to the cooling fluid circuit (220). In other words, the load of the pump mechanism (221) that originally has a small burden is increased by preferentially increasing the load. For this reason, it is possible to suppress an increase in input necessary to cope with an increase in load, and it is possible to suppress a decrease in the coefficient of performance. As a result, an increase in power consumption of the entire refrigeration apparatus can be suppressed.

Furthermore, in the present invention, as the power consumption of the power consumption pump mechanism without increasing (221) of the refrigerant circuit (20) when the load is increased to increase large, the target values such as the outside air temperature and the refrigerant flow rate It is set based on the ambient conditions of the supercooling heat exchanger (210). Therefore, it is possible to preferentially increase the power consumption of the pump mechanism (221) according to the load state.

Also, because the load state of the refrigeration system is estimated only by information obtained from the cooling fluid circuit (220), the communication circuit is used for exchanging signals between the refrigerant circuit (20) and the cooling fluid circuit (220). There is no need to lay wiring .

In the ninth aspect , as the outside air temperature increases, the power consumption of the pump mechanism (221) is preferentially increased without increasing the power consumption of the heat source side compressor (41, 42, 43). According to this, since the power consumption of the pump mechanism (221) can be preferentially increased according to the load state, the decrease in the coefficient of performance of the refrigeration apparatus can be suppressed more easily and effectively. Increase in power can be suppressed.

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

Embodiment 1 of the Invention
The refrigeration apparatus (10) of the first embodiment is installed in a convenience store or the like, and performs air conditioning in the store and cooling in the showcase. As shown in FIG. 1, the refrigeration apparatus (10) includes a supercooling heat exchanger (210) and a supercooling compressor (221), and supercooling through which a supercooling refrigerant as a cooling fluid flows. And a refrigerant circuit (20) having a refrigerant circuit (220), a use side heat exchanger (101, 111, 131) and a heat source side compressor (41, 42, 43) through which the refrigerant flows. The refrigeration apparatus (10) is configured to supercool the refrigerant flowing through the refrigerant circuit (20) via the supercooling heat exchanger (210) of the supercooling refrigerant circuit (220). That is, the supercooling refrigerant circuit (220) constitutes the cooling fluid circuit according to the present invention.

  The configuration of the refrigeration apparatus (10) will be specifically described below.

  The refrigeration unit (10) includes an outdoor unit (11), an air conditioning unit (12), a refrigerated showcase (13), a refrigeration showcase (14), a booster unit (15), a supercooling unit (200 ) And are provided. In the refrigeration apparatus (10), the outdoor unit (11) and the supercooling unit (200) are installed outdoors, and the remaining air conditioning units (12) and the like are installed in a store such as a convenience store.

  The supercooling unit (200) includes a refrigerant passage (205), a supercooling refrigerant circuit (220), a supercooling heat exchanger (210), and a controller (240) as control means.

  On the other hand, the outdoor unit (11) has an outdoor circuit (40), the air conditioning unit (12) has an air conditioning circuit (100), the refrigerated showcase (13) has a refrigerated circuit (110), and a refrigerated showcase (14 ) Is provided with a refrigeration circuit (130), and the booster unit (15) is provided with a booster circuit (140). In the refrigeration apparatus (10), the refrigerant circuit (20) of the refrigeration apparatus (10) through which refrigerant flows by connecting these circuits (40, 100,...) And the refrigerant passage (205) of the supercooling unit (200) with pipes. Is configured.

  The refrigerant circuit (20) includes a first liquid side connection pipe (21), a second liquid side connection pipe (22), a first gas side connection pipe (23), and a second gas side connection pipe ( 24) and are provided.

  The first liquid side communication pipe (21) connects one end of the refrigerant passage (205) of the supercooling unit (200) to the outdoor circuit (40). One end of the second liquid side connecting pipe (22) is connected to the other end of the refrigerant passage (205). The other end of the second liquid side connecting pipe (22) branches into three and is connected to the air conditioning circuit (100), the refrigeration circuit (110), and the refrigeration circuit (130). A liquid side shut-off valve (25) is provided in a branch pipe connected to the refrigeration circuit (130) in the second liquid side communication pipe (22).

  One end of the first gas side communication pipe (23) is branched into two and connected to the refrigeration circuit (110) and the booster circuit (140). A gas side closing valve (26) is provided in a branch pipe connected to the booster circuit (140) in the first gas side communication pipe (23). The other end of the first gas side communication pipe (23) is connected to the outdoor circuit (40). The second gas side communication pipe (24) connects the air conditioning circuit (100) to the outdoor circuit (40).

<Outdoor unit>
The outdoor unit (11) constitutes a heat source side device of the refrigeration apparatus (10). The outdoor unit (11) includes an outdoor circuit (40).

  The outdoor circuit (40) is provided with a variable capacity compressor (41) as a heat source side compressor, a first fixed capacity compressor (42), and a second fixed capacity compressor (43). The outdoor circuit (40) is provided with an outdoor heat exchanger (44), a receiver (45), and an outdoor expansion valve (46). The outdoor circuit (40) includes three suction pipes (61, 62, 63), two discharge pipes (64, 65), four liquid pipes (81, 82, 83, 84), 1 And two high-pressure gas pipes (66). Further, the outdoor circuit (40) is provided with three four-way switching valves (51, 52, 53), one liquid side closing valve (54), and two gas side closing valves (55, 56). It has been.

  In this outdoor circuit (40), the liquid side closing valve (54) has a first liquid side connecting pipe (21), the first gas side closing valve (55) has a first gas side connecting pipe (23), A second gas side communication pipe (24) is connected to the second gas side closing valve (56).

  The variable capacity compressor (41), the first fixed capacity compressor (42), and the second fixed capacity compressor (43) are all hermetic and high pressure dome type scroll compressors. Electric power is supplied to the variable capacity compressor (41) via an inverter. The capacity of the variable capacity compressor (41) can be changed by changing the rotation speed of the compressor motor by changing the output frequency of the inverter. On the other hand, in the first and second fixed capacity compressors (42, 43), the compressor motor is always operated at a constant rotational speed, and the capacity cannot be changed.

  One end of the first suction pipe (61) is connected to the first gas-side closing valve (55). The first suction pipe (61) is branched into a first branch pipe (61a) and a second branch pipe (61b) at the other end, and the first branch pipe (61a) is a variable capacity compressor (41). ), The second branch pipe (61b) is connected to the third four-way selector valve (53). In the second branch pipe (61b) of the first suction pipe (61), a check valve that allows only the flow of the refrigerant from the first gas side stop valve (55) toward the third four-way selector valve (53) ( CV-1) is provided.

  The second suction pipe (62) has one end connected to the third four-way switching valve (53) and the other end connected to the suction side of the first fixed capacity compressor (42).

  One end of the third suction pipe (63) is connected to the second four-way switching valve (52). The third suction pipe (63) is branched at the other end into a first branch pipe (63a) and a second branch pipe (63b), and the first branch pipe (63a) is a second fixed capacity compressor. The second branch pipe (63b) is connected to the third four-way switching valve (53) on the suction side of (43). The second branch pipe (63b) of the third suction pipe (63) has a check valve that allows only the flow of refrigerant from the second four-way switching valve (52) to the third four-way switching valve (53). CV-2) is provided.

  The first discharge pipe (64) is branched at one end into a first branch pipe (64a) and a second branch pipe (64b), and the first branch pipe (64a) is connected to the variable capacity compressor (41). The second branch pipe (64b) is connected to the discharge side of the first fixed capacity compressor (42) on the discharge side. The other end of the first discharge pipe (64) is connected to the first four-way switching valve (51). In the second branch pipe (64b) of the first discharge pipe (64), a check valve that allows only the flow of the refrigerant from the first fixed capacity compressor (42) to the first four-way selector valve (51) ( CV-3) is provided.

  The second discharge pipe (65) has one end on the suction side of the second fixed capacity compressor (43) and the other end just before the first four-way switching valve (51) in the first discharge pipe (64). It is connected. The second discharge pipe (65) is provided with a check valve (CV-4) that allows only the refrigerant to flow from the second fixed capacity compressor (43) to the first four-way switching valve (51). Yes.

  The outdoor heat exchanger (44) is a cross-fin type fin-and-tube heat exchanger. In the outdoor heat exchanger (44), heat is exchanged between the refrigerant and the outdoor air. One end of the outdoor heat exchanger (44) is connected to the first four-way switching valve (51) via the closing valve (57). On the other hand, the other end of the outdoor heat exchanger (44) is connected to the top of the receiver (45) via the first liquid pipe (81). The first liquid pipe (81) is provided with a check valve (CV-5) that allows only the refrigerant to flow from the outdoor heat exchanger (44) to the receiver (45).

  One end of a second liquid pipe (82) is connected to the bottom of the receiver (45) via a closing valve (58). The other end of the second liquid pipe (82) is connected to the liquid side closing valve (54). The second liquid pipe (82) is provided with a check valve (CV-6) that allows only the refrigerant to flow from the receiver (45) to the liquid side closing valve (54).

  One end of the third liquid pipe (83) is connected between the check valve (CV-6) and the liquid side closing valve (54) in the second liquid pipe (82). The other end of the third liquid pipe (83) is connected to the top of the receiver (45) via the first liquid pipe (81). The third liquid pipe (83) is provided with a check valve (CV-7) that allows only the refrigerant to flow from one end to the other end.

  One end of the fourth liquid pipe (84) is connected between the closing valve (58) and the check valve (CV-6) in the second liquid pipe (82). The other end of the fourth liquid pipe (84) is connected between the outdoor heat exchanger (44) and the check valve (CV-5) in the first liquid pipe (81). The fourth liquid pipe (84) is provided with a check valve (CV-8) and an outdoor expansion valve (46) in that order from one end to the other end. This check valve (CV-8) only allows the refrigerant to flow from one end to the other end of the fourth liquid pipe (84). The outdoor expansion valve (46) is an electronic expansion valve.

  One end of the high-pressure gas pipe (66) is connected immediately before the first four-way switching valve (51) in the first discharge pipe (64). The high pressure gas pipe (66) is branched into a first branch pipe (66a) and a second branch pipe (66b) on the other end side, and the first branch pipe (66a) is connected to the first liquid pipe (81). The second branch pipe (66b) is connected to the third four-way selector valve (53) on the downstream side of the check valve (CV-5). The first branch pipe (66a) of the high-pressure gas pipe (66) is provided with a solenoid valve (SV-7) and a check valve (CV-9). The check valve (CV-9) is disposed downstream of the solenoid valve (SV-7) and allows only the refrigerant to flow from the solenoid valve (SV-7) to the first liquid pipe (81).

  The first four-way switching valve (51) has a first port at the end of the first discharge pipe (64), a second port at the second four-way switching valve (52), and a third port at outdoor heat. The fourth port is connected to the exchanger (44) and the second gas side shut-off valve (56), respectively. The first four-way selector valve (51) is in 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. ) And a second state (state indicated by a broken line in FIG. 1) in which the first port and the fourth port communicate with each other and the second port and the third port communicate with each other.

  The second four-way switching valve (52) has a first port downstream of the check valve (CV-4) in the second discharge pipe (65) and a second port of the second suction pipe (62). At the start, the fourth port is connected to the second port of the first four-way switching valve (51). The second four-way switching valve (52) has a third port sealed. The second four-way selector valve (52) is in 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. ) And a second state (state indicated by a broken line in FIG. 1) in which the first port and the fourth port communicate with each other and the second port and the third port communicate with each other.

  The third four-way selector valve (53) has a first port at the end of the second branch pipe (66b) of the high-pressure gas pipe (66) and a second port at the start of the second suction pipe (62). The third port is connected to the end of the second branch pipe (61b) of the first suction pipe (61), and the fourth port is connected to the end of the second branch pipe (63b) of the third suction pipe (63). ing. The third four-way selector valve (53) is in 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. ) And a second state (state indicated by a broken line in FIG. 1) in which the first port and the fourth port communicate with each other and the second port and the third port communicate with each other.

  The outdoor circuit (40) is further provided with an injection pipe (85), a communication pipe (87), an oil separator (75), and an oil return pipe (76). The outdoor circuit (40) is also provided with four oil equalizing pipes (71, 72, 73, 74).

  The injection pipe (85) is for performing so-called liquid injection. One end of the injection pipe (85) is connected between the check valve (CV-8) and the outdoor expansion valve (46) in the fourth liquid pipe (84), and the other end is connected to the first suction pipe (61). Has been. The injection pipe (85) is provided with a closing valve (59) and a flow rate adjusting valve (86) in order from one end to the other end. The flow rate control valve (86) is an electronic expansion valve.

  One end of the communication pipe (87) is between the closing valve (59) and the flow control valve (86) in the injection pipe (85), and the other end is in the first branch pipe (66a) of the high-pressure gas pipe (66). It is connected to the upstream side of the solenoid valve (SV-7). The communication pipe (87) is provided with a check valve (CV-10) that allows only the refrigerant to flow from one end to the other end.

  The oil separator (75) is provided upstream of the connection position of the second discharge pipe (65) and the high-pressure gas pipe (66) in the first discharge pipe (64). The oil separator (75) is for separating the refrigerating machine oil from the discharge gas of the compressor (41, 42).

  One end of the oil return pipe (76) is connected to the oil separator (75). The oil return pipe (76) is branched into a first branch pipe (76a) and a second branch pipe (76b) at the other end, and the first branch pipe (76a) regulates the flow rate in the injection pipe (85). The second branch pipe (76b) is connected to the second suction pipe (62) on the downstream side of the valve (86). Further, one solenoid valve (SV-5, SV-6) is provided in each of the first branch pipe (76a) and the second branch pipe (76b) of the oil return pipe (76). When the solenoid valve (SV-5) of the first branch pipe (76a) is opened, the refrigeration oil separated by the oil separator (75) is sent back to the first suction pipe (61) through the injection pipe (85). On the other hand, when the solenoid valve (SV-6) of the second branch pipe (76b) is opened, the refrigeration oil separated by the oil separator (75) is sent back to the second suction pipe (62).

  The first oil equalizing pipe (71) has one end connected to the variable capacity compressor (41) and the other end connected to the second suction pipe (62). The first oil equalizing pipe (71) is provided with a solenoid valve (SV-1). The second oil equalizing pipe (72) has one end connected to the first fixed capacity compressor (42) and the other end connected to the first branch pipe (63a) of the third suction pipe (63). The second oil equalizing pipe (72) is provided with a solenoid valve (SV-2). The third oil equalizing pipe (73) has one end connected to the second fixed capacity compressor (43) and the other end connected to the first branch pipe (61a) of the first suction pipe (61). The third oil level equalizing pipe (73) is provided with a solenoid valve (SV-3). The fourth oil equalizing pipe (74) has one end connected to the upstream side of the solenoid valve (SV-2) in the second oil equalizing pipe (72) and the other end connected to the first branch pipe (61) of the first suction pipe (61). 61a). The fourth oil equalizing pipe (74) is provided with a solenoid valve (SV-4). By appropriately opening and closing the solenoid valves (SV-1 to SV-4) of the oil equalizing pipes (71 to 74), the amount of refrigerating machine oil stored in each compressor (41, 42, 43) is averaged.

  Although not shown, the outdoor circuit (40) is also provided with various sensors and pressure switches.

  The outdoor unit (11) is provided with an outdoor fan (48). Outdoor air is sent to the outdoor heat exchanger (44) by the outdoor fan (48).

<Air conditioning unit>
The air conditioning unit (12) constitutes a use side device. The air conditioning unit (12) includes an air conditioning circuit (100). This air conditioning circuit (100) has a liquid side end connected to the second liquid side connecting pipe (22) and a gas side end connected to the second gas side connecting pipe (24).

  In the air conditioning circuit (100), an air conditioning expansion valve (102) and an air conditioning heat exchanger (101) as a use side heat exchanger are provided in order from the liquid side end to the gas side end. The air conditioning heat exchanger (101) is a cross fin type fin-and-tube heat exchanger. In the air conditioning heat exchanger (101), heat is exchanged between the refrigerant and the room air. On the other hand, the air conditioning expansion valve (102) is an electronic expansion valve.

  The air conditioning unit (12) is provided with an air conditioning fan (105). The indoor air in the store is sent to the air conditioning heat exchanger (101) by the air conditioning fan (105).

<Refrigerated showcase>
The refrigerated showcase (13) constitutes a use side device. The refrigerated showcase (13) includes a refrigerated circuit (110). The refrigeration circuit (110) has a liquid side end connected to the second liquid side connecting pipe (22) and a gas side end connected to the first gas side connecting pipe (23).

  In the refrigeration circuit (110), a refrigeration solenoid valve (114), a refrigeration expansion valve (112), and a refrigeration heat exchanger (111) as a use side heat exchanger are arranged in order from the liquid side end to the gas side end. Is provided. The refrigeration heat exchanger (111) is a cross-fin type fin-and-tube heat exchanger. In the refrigerated heat exchanger (111), heat is exchanged between the refrigerant and the internal air. The refrigeration expansion valve (112) is a temperature automatic expansion valve. The temperature sensing cylinder (113) of the refrigeration expansion valve (112) is attached to a pipe on the outlet side of the refrigeration heat exchanger (111).

  The refrigerated showcase (13) is provided with a refrigerator fan (115). To the refrigerated heat exchanger (111), the air in the refrigerator of the refrigerated showcase (13) is sent by the fan (115) in the refrigerator.

<Frozen showcase>
The refrigerated showcase (14) constitutes a use side device. The refrigeration showcase (14) includes a refrigeration circuit (130). The refrigeration circuit (130) has a liquid side end connected to the second liquid side communication pipe (22). The gas side end of the refrigeration circuit (130) is connected to the booster unit (15) via a pipe.

  In the refrigeration circuit (130), a refrigeration solenoid valve (134), a refrigeration expansion valve (132), and a refrigeration heat exchanger (131) as a use side heat exchanger are arranged in order from the liquid side end to the gas side end. Is provided. The refrigeration heat exchanger (131) is a cross-fin type fin-and-tube heat exchanger. In the refrigeration heat exchanger (131), heat is exchanged between the refrigerant and the internal air. The refrigeration expansion valve (132) is a temperature automatic expansion valve. The temperature sensing cylinder (133) of the refrigeration expansion valve (132) is attached to a pipe on the outlet side of the refrigeration heat exchanger (131).

  The freezer showcase (14) is provided with a freezer fan (135). To the freezing heat exchanger (131), the air in the freezer showcase (14) is sent by the freezer fan (135).

<Booster unit>
The booster unit (15) includes a booster circuit (140). The booster circuit (140) is provided with a booster compressor (141), a suction pipe (143), a discharge pipe (144), and a bypass pipe (150).

  The booster compressor (141) is a fully hermetic high-pressure dome type scroll compressor. Electric power is supplied to the booster compressor (141) via an inverter. The capacity of the booster compressor (141) can be changed by changing the rotation speed of the compressor motor by changing the output frequency of the inverter.

  The end of the suction pipe (143) is connected to the suction side of the booster compressor (141). The starting end of the suction pipe (143) is connected to the gas side end of the refrigeration circuit (130) via a pipe.

  The discharge pipe (144) has its start end connected to the discharge side of the booster compressor (141) and its end connected to the first gas side connecting pipe (23). The discharge pipe (144) is provided with a high-pressure switch (148), an oil separator (145), and a discharge-side check valve (149) in that order from the beginning to the end. The discharge-side check valve (149) only allows the refrigerant to flow from the start end to the end of the discharge pipe (144).

  The oil separator (145) is for separating the refrigerating machine oil from the discharge gas of the booster compressor (141). One end of an oil return pipe (146) is connected to the oil separator (145). The other end of the oil return pipe (146) is connected to the suction pipe (143). The oil return pipe (146) is provided with a capillary tube (147). The refrigerating machine oil separated by the oil separator (145) is sent back to the suction side of the booster compressor (141) through the oil return pipe (146).

  The bypass pipe (150) has a start end connected to the suction pipe (143) and a terminal end connected between the oil separator (145) and the discharge check valve (149) in the discharge pipe (64). The bypass pipe (150) is provided with a bypass check valve (151) that allows only the refrigerant to flow from the start end to the end.

<Supercooling unit>
As described above, the supercooling unit (200) includes the refrigerant passage (205), the supercooling refrigerant circuit (220), the supercooling heat exchanger (210), and the controller (240).

  The refrigerant passage (205) has one end connected to the first liquid side connecting pipe (21) and the other end connected to the second liquid side connecting pipe (22).

  The supercooling refrigerant circuit (220) includes a supercooling compressor (221), a supercooling outdoor heat exchanger (222), a supercooling expansion valve (223) as an expansion mechanism, and supercooling heat. It is a closed circuit comprised by connecting a exchanger (210) in order with piping. In the supercooling refrigerant circuit (220), a vapor compression refrigeration cycle is performed by circulating the filled supercooling refrigerant by the supercooling compressor (221). That is, in the supercooling refrigerant circuit (220), a supercooling refrigerant different from the refrigerant flowing through the refrigerant circuit (20) of the refrigeration apparatus (10) is circulated. In this embodiment, the supercooling compressor (221) constitutes a pump mechanism, and the supercooling outdoor heat exchanger (222) constitutes a heat source side heat exchanger.

  The supercooling compressor (221) is a hermetically sealed high-pressure dome type scroll compressor. Electric power is supplied to the subcooling compressor (221) via an inverter. The capacity of the subcooling compressor (221) can be changed by changing the rotation speed of the compressor motor by changing the output frequency of the inverter. The subcooling outdoor heat exchanger (222) is a cross-fin type fin-and-tube heat exchanger. In the subcooling outdoor heat exchanger (222), heat is exchanged between the supercooling refrigerant and the outdoor air. The supercooling expansion valve (223) is an electronic expansion valve.

  The supercooling heat exchanger (210) is a so-called plate heat exchanger. A plurality of first flow paths (211) and a plurality of second flow paths (212) are formed in the supercooling heat exchanger (210). A supercooling refrigerant circuit (220) is connected to the first flow path (211), and a refrigerant path (205) is connected to the second flow path (212). The supercooling heat exchanger (210) exchanges heat between the supercooling refrigerant flowing through the first flow path (211) and the refrigerant of the refrigeration apparatus (10) flowing through the second flow path (212). .

  The supercooling unit (200) is also provided with various sensors and pressure switches. Specifically, in the refrigerant passage (205), the outlet side refrigerant is located in a portion closer to the other end than the supercooling heat exchanger (210), that is, a portion closer to the end connected to the second liquid side connecting pipe (22). A temperature sensor (237) is provided.

  The supercooling unit (200) is provided with an outside air temperature sensor (231) and an outdoor fan (230) for detecting the outside air temperature Ta. Outdoor air is sent to the subcooling outdoor heat exchanger (222) by the outdoor fan (230). That is, in the present embodiment, the outside air temperature Ta is used as the ambient condition of the supercooling heat exchanger (210).

  The controller (240) receives the liquid refrigerant outlet temperature Tout detected by the outlet side refrigerant temperature sensor (237), the outside air temperature Ta detected by the outside air temperature sensor (231), and the like. The controller (240) controls the power consumption of the supercooling compressor (221) by switching between starting and stopping of the supercooling compressor (221) based on the detected value of the input sensor. It is configured as follows.

-Operation of refrigeration equipment-
Among the operation operations performed by the refrigeration apparatus (10), main ones will be described.

<Cooling operation>
The cooling operation is an operation of cooling the interior air in the refrigerated showcase (13) and the freezer showcase (14) and cooling the room air by cooling the room air in the air conditioning unit (12).

  As shown in FIG. 2, during the cooling operation, the first four-way selector valve (51), the second four-way selector valve (52), and the third four-way selector valve (53) are each set to the first state. The Moreover, while the outdoor expansion valve (46) is fully closed, the opening degrees of the air conditioning expansion valve (102), the refrigeration expansion valve (112), and the refrigeration expansion valve (132) are adjusted as appropriate. In this state, the variable capacity compressor (41), the first fixed capacity compressor (42), the second fixed capacity compressor (43), and the booster compressor (141) are operated. During the cooling operation, the supercooling unit (200) is in an operating state. The operation of the supercooling unit (200) will be described later.

  The refrigerant discharged from the variable capacity compressor (41), the first fixed capacity compressor (42), and the second fixed capacity compressor (43) passes through the first four-way switching valve (51) and is heated outside the room. Sent to exchanger (44). In the outdoor heat exchanger (44), the refrigerant dissipates heat to the outdoor air and condenses. The refrigerant condensed in the outdoor heat exchanger (44) passes through the first liquid pipe (81), the receiver (45), and the second liquid pipe (82) in order and flows into the first liquid side connecting pipe (21). To do.

  The refrigerant that has flowed into the first liquid side communication pipe (21) flows into the refrigerant passage (205) of the supercooling unit (200). The refrigerant flowing into the refrigerant passage (205) is further cooled while passing through the second flow path (212) of the supercooling heat exchanger (210). The supercooled liquid refrigerant (supercooled refrigerant) cooled by the supercooling heat exchanger (210) passes through the second liquid side connecting pipe (22) and is supplied with the air conditioning circuit (100) and the refrigeration circuit (110). And the refrigeration circuit (130).

  The refrigerant flowing into the air conditioning circuit (100) is reduced in pressure when passing through the air conditioning expansion valve (102) and then introduced into the air conditioning heat exchanger (101). In the air conditioning heat exchanger (101), the refrigerant absorbs heat from the room air and evaporates. At that time, in the air conditioning heat exchanger (101), the evaporation temperature of the refrigerant is set to about 5 ° C., for example. In the air conditioning unit (12), the indoor air cooled by the air conditioning heat exchanger (101) is supplied into the store.

  The refrigerant evaporated in the air conditioning heat exchanger (101) flows into the outdoor circuit (40) through the second gas side communication pipe (24), and then the first four-way switching valve (51) and the second four-way It passes through the switching valve (52) in order and flows into the third suction pipe (63). A part of the refrigerant flowing into the third suction pipe (63) passes through the first branch pipe (63a) and is sucked into the second fixed capacity compressor (43), and the rest of the refrigerant flows into the second branch pipe (63b). It passes through the third four-way selector valve (53) and the second suction pipe (62) in order, and is sucked into the first fixed capacity compressor (42).

  The refrigerant flowing into the refrigeration circuit (110) is decompressed when passing through the refrigeration expansion valve (112) and then introduced into the refrigeration heat exchanger (111). In the refrigeration heat exchanger (111), the refrigerant absorbs heat from the internal air and evaporates. At that time, in the refrigeration heat exchanger (111), the evaporation temperature of the refrigerant is set to, for example, about −5 ° C. The refrigerant evaporated in the refrigeration heat exchanger (111) flows into the first gas side communication pipe (23). In the refrigerated showcase (13), the in-compartment air cooled by the refrigerated heat exchanger (111) is supplied into the interior, and the interior temperature is maintained at about 5 ° C., for example.

  The refrigerant flowing into the refrigeration circuit (130) is reduced in pressure when passing through the refrigeration expansion valve (132) and then introduced into the refrigeration heat exchanger (131). In the refrigeration heat exchanger (131), the refrigerant absorbs heat from the internal air and evaporates. At that time, in the refrigeration heat exchanger (131), the evaporation temperature of the refrigerant is set to, for example, about −30 ° C. In the refrigeration showcase (14), the in-compartment air cooled by the refrigeration heat exchanger (131) is supplied into the interior, and the in-compartment temperature is maintained at, for example, about -20 ° C.

  The refrigerant evaporated in the refrigeration heat exchanger (131) flows into the booster circuit (140) and is sucked into the booster compressor (141). The refrigerant compressed by the booster compressor (141) flows into the first gas side communication pipe (23) through the discharge pipe (144).

  In the first gas side communication pipe (23), the refrigerant sent from the refrigeration circuit (110) and the refrigerant sent from the booster circuit (140) merge. These refrigerants pass through the first gas side communication pipe (23) and flow into the first suction pipe (61) of the outdoor circuit (40). The refrigerant flowing into the first suction pipe (61) is sucked into the variable capacity compressor (41) through the first branch pipe (61a).

<Heating operation>
The heating operation is an operation for heating the interior of the store by cooling the indoor air in the refrigerated showcase (13) and the refrigerated showcase (14) and heating the indoor air in the air conditioning unit (12).

  As shown in FIG. 3, in the outdoor circuit (40), the first four-way switching valve (51) is in the second state, the second four-way switching valve (52) is in the first state, and the third four-way switching valve. (53) is set to the first state, respectively. Moreover, while the outdoor expansion valve (46) is fully closed, the opening degrees of the air conditioning expansion valve (102), the refrigeration expansion valve (112), and the refrigeration expansion valve (132) are adjusted as appropriate. In this state, the variable capacity compressor (41) and the booster compressor (141) are operated, and the first fixed capacity compressor (42) and the second fixed capacity compressor (43) are stopped. Further, the outdoor heat exchanger (44) enters a dormant state without the refrigerant being sent. During the first heating operation, the supercooling unit (200) is stopped.

  The refrigerant discharged from the variable capacity compressor (41) passes through the first four-way switching valve (51) and the second gas side communication pipe (24) in this order, and the air conditioning heat exchanger (101) of the air conditioning circuit (100). The heat is released into the room air and condensed. In the air conditioning unit (12), room air heated by the air conditioning heat exchanger (101) is supplied into the store. The refrigerant condensed in the air conditioning heat exchanger (101) is distributed to the refrigeration circuit (110) and the refrigeration circuit (130) through the second liquid side communication pipe (22).

  In the refrigerated showcase (13) and the freezer showcase (14), the internal air is cooled in the same manner as in the cooling operation. The refrigerant flowing into the refrigeration circuit (110) evaporates in the refrigeration heat exchanger (111) and then flows into the first gas side communication pipe (23). On the other hand, the refrigerant that has flowed into the refrigeration circuit (130) evaporates in the refrigeration heat exchanger (131), is then compressed in the booster compressor (141), and then flows into the first gas side communication pipe (23). The refrigerant flowing into the first gas side communication pipe (23) passes through the first suction pipe (61) and is then sucked into the variable capacity compressor (41) and compressed.

  Thus, in the first heating operation, the refrigerant absorbs heat in the refrigeration heat exchanger (111) and the refrigeration heat exchanger (131), and the refrigerant radiates heat in the air conditioning heat exchanger (101). And the inside of a store is heated using the heat | fever which the refrigerant | coolant absorbed from the air in a store | warehouse | chamber with the refrigeration heat exchanger (111) and the freezing heat exchanger (131).

  During the heating operation, the first fixed capacity compressor (42) may be operated. Whether to operate the first fixed capacity compressor (42) is determined according to the cooling load in the refrigerated showcase (13) and the refrigerated showcase (14).

  As described above, during the heating operation, the outside air temperature Ta is low, and the predetermined capacity can be sufficiently exhibited only by the refrigeration apparatus (10). Therefore, the supercooling compressor (221) is used as in the cooling operation. Never happen.

−Operation of supercooling unit−
The operation of the supercooling unit (200) will be described. In the operation state of the supercooling unit (200), the supercooling compressor (221) is operated, and the opening degree of the supercooling expansion valve (223) is appropriately adjusted.

  As shown in FIG. 2, the supercooling refrigerant discharged from the supercooling compressor (221) dissipates heat to the outdoor air and condenses in the supercooling outdoor heat exchanger (222). The supercooling refrigerant condensed in the supercooling outdoor heat exchanger (222) is decompressed when passing through the supercooling expansion valve (223), and then the first flow path of the supercooling heat exchanger (210). Flows into (211). In the first flow path (211) of the supercooling heat exchanger (210), the supercooling refrigerant absorbs heat from the refrigerant in the second flow path (212) and evaporates. The supercooling refrigerant evaporated in the supercooling heat exchanger (210) is sucked into the supercooling compressor (221) and compressed.

  The controller (240) receives the outside air temperature Ta detected by the outside air temperature sensor (231) and the liquid refrigerant outlet temperature Tout detected by the outlet side refrigerant temperature sensor (237). In the present embodiment, the controller (240) determines whether to continue or stop the operation of the supercooling compressor (221) based on the outside air temperature Ta.

  A control operation of the controller (240) will be described.

  As shown in FIG. 4, a target liquid refrigerant outlet temperature Eom as a target value prepared in advance is set. Based on the target liquid refrigerant outlet temperature Eom, the controller (240) controls the operating capacity of the supercooling compressor (221). The target liquid refrigerant outlet temperature Eom is set so as to decrease as the outside air temperature Ta increases.

  Specifically, the target liquid refrigerant outlet temperature Eom is set to Eom = − (Ta−40) + 10 ° C. when the outside air temperature Ta is 25 ° C. ≦ Ta ≦ 40 ° C. Further, when Ta <25 ° C., Eom = 25 ° C. (constant), and when Ta> 40 ° C., Eom = 10 ° C. (constant).

  Next, control of the operating capacity of the supercooling compressor (221) of the controller (240) will be described with reference to FIG.

  First, the frequency of the supercooling compressor (221) is a predetermined frequency. In step S1, the controller (240) calculates the difference (Tout−Eom) between the liquid refrigerant outlet temperature Tout and the target liquid refrigerant outlet temperature Eom, and when the difference is less than −1.0 ° C. (FIG. 5). Area A) proceeds to step S2. When the difference is not less than −1.0 and less than 1.0 (region B in the figure), the process is terminated. Further, when the difference exceeds −1.0 ° C. (region C in the figure), the process proceeds to step S4.

  In step S2, the controller (240) determines whether or not the frequency of the supercooling compressor (221) is the lowest frequency. And if it is the lowest frequency, it will be complete | finished, and if it is not the lowest frequency, it will move to step S3.

  In step S3, the frequency of the supercooling compressor (221) is decreased by a predetermined step, and the process ends.

  On the other hand, in step S4, it is determined whether or not the frequency of the supercooling compressor (221) is the highest frequency. And if it is the highest frequency, it will be complete | finished, and if it is not the highest frequency, it will move to step S5.

  In step S5, the frequency of the supercooling compressor (221) is increased by a predetermined step, and the process ends.

  The controller (240) performs the above routine every 30 seconds.

  Thus, as the outside air temperature Ta increases, the controller (240) sets the target liquid refrigerant outlet temperature Eom lower. In order to bring the liquid refrigerant outlet temperature Tout closer to the lower target liquid refrigerant outlet temperature Eom, it is necessary to increase the operating capacity by increasing the operating frequency of the supercooling compressor (221). Therefore, in the present embodiment, when the load of the refrigeration apparatus (10) increases due to the increase in the outside air temperature Ta, the controller (240) adjusts the target liquid refrigerant outlet temperature Eom so that the supercooling compressor (221 ) Is preferentially increased. As a result, the power consumption of the supercooling compressor (221) increases, and the power consumption of the supercooling refrigerant circuit (220) increases preferentially.

  In the supercooling unit (200) of the present embodiment, when the liquid refrigerant outlet temperature Tout differs from the target liquid refrigerant outlet temperature Eom by 1.0 ° C. or more, the controller (240) uses the supercooling compressor (221). The operating capacity is changed, but may be changed when there is a difference of ± 1.5 ° C or ± 2.0 ° C.

-Effect of Embodiment 1-
As described above, the evaporating temperature of the supercooling refrigerant in the supercooling heat exchanger (210) is higher than the evaporating temperature of the refrigerant in the use side heat exchanger (101, 111, 131). The high / low pressure difference of the refrigeration cycle in the subcooling refrigerant circuit (220) is smaller than the high / low pressure difference of the refrigeration cycle in the refrigerant circuit (20). The refrigeration apparatus (10) of the present embodiment does not increase the refrigerant circulation amount in the refrigerant circuit (20) having a large high / low pressure difference in the refrigeration cycle, but a subcooling refrigerant circuit ( In 220), the operating frequency of the supercooling compressor (221) is increased to increase the power consumption (work amount) preferentially so as to increase the circulation amount of the supercooling refrigerant. That is, the increase in load is dealt with by preferentially increasing the operating capacity of the subcooling compressor (221) that originally has a small burden. For this reason, it is possible to suppress an increase in input necessary to cope with an increase in load, and it is possible to suppress a decrease in the coefficient of performance. As a result, an increase in power consumption of the entire refrigeration apparatus (10) can be suppressed.

  In this embodiment, as the outside air temperature increases, the operating capacity of the supercooling compressor (221) is preferentially increased with respect to the heat source side compressor (41, 42, 43). For this reason, since the operating capacity of the supercooling compressor (221) can be preferentially increased in accordance with the change in the high / low pressure difference of the refrigeration cycle according to the outside air temperature, the refrigeration apparatus (10 ) Of the coefficient of performance can be suppressed, and the increase in the overall power consumption can be suppressed.

-Each modification of Embodiment 1-
Each of the modified examples (modified examples 1 to 6) has the refrigerant temperature at the outlet of the supercooling heat exchanger (210) based on various parameters other than the outside air temperature as the ambient conditions of the supercooling heat exchanger (210). A target value is set.

-Modification 1-
In the refrigeration apparatus (10) of the first modification, as the ambient condition of the supercooling heat exchanger (210), the supercooling degree of the refrigerant in the refrigerant circuit (20) flowing through the supercooling heat exchanger (210) is used. It is done. In this case, although not shown, temperature sensors as temperature detecting means for the refrigerant are provided on the inlet side and the outlet side of the supercooling heat exchanger (210) in the refrigerant passage (205). The detected temperatures of these temperature sensors are input to the controller (240), and the difference between the detected temperatures is used as the degree of supercooling. In the controller (240), the target liquid refrigerant outlet temperature Eom is set based on the degree of refrigerant supercooling. That is, it is estimated that the load increases as the degree of supercooling decreases, and the target liquid refrigerant outlet temperature Eom is set to be low.

-Modification 2-
In the refrigeration apparatus (10) of the second modification, the refrigerant flow rate of the refrigerant circuit (20) flowing through the supercooling heat exchanger (210) is used as the ambient condition of the supercooling heat exchanger (210). In this case, although not shown, a flow rate sensor as a refrigerant flow rate detecting means is provided in the refrigerant passage (205), and the detected flow rate is input to the controller (240). In the controller (240), the target liquid refrigerant outlet temperature Eom is set based on the refrigerant flow rate. That is, it is estimated that the load increases as the refrigerant flow rate increases, and the target liquid refrigerant outlet temperature Eom is set to be low.

-Modification 3-
In the refrigeration apparatus (10) of the third modified example, the temperature difference before and after the supercooling of the supercooling refrigerant in the supercooling heat exchanger (210) is used as the ambient condition of the supercooling heat exchanger (210). . In this case, although not shown, temperature sensors as temperature detecting means for the supercooling refrigerant are provided on the inlet side and the outlet side of the supercooling heat exchanger (210). The detected temperatures of these temperature sensors are input to the controller (240), and the detected temperature difference is used as the temperature difference before and after the supercooling of the supercooling refrigerant. In the controller (240), the target liquid refrigerant outlet temperature Eom is set based on the temperature difference of the supercooling refrigerant. That is, it is estimated that the load increases as the temperature difference becomes smaller, and the target liquid refrigerant outlet temperature Eom is set to be lower.

-Modification 4-
In the refrigeration apparatus (10) of Modification 4, the flow rate of the supercooling refrigerant flowing through the supercooling heat exchanger (210) is used as the ambient condition of the supercooling heat exchanger (210). In this case, although not shown, a flow rate sensor as a flow rate detection means for the supercooling refrigerant is provided on the inlet side or the outlet side of the supercooling heat exchanger (210), and the detected flow rate is input to the controller (240). The In the controller (240), the target liquid refrigerant outlet temperature Eom is set based on the detected flow rate. That is, it is estimated that the load increases as the flow rate of the supercooling refrigerant increases, and the target liquid refrigerant outlet temperature Eom is set to be low.

-Modification 5-
In the refrigeration apparatus (10) of Modification 5, the high pressure of the supercooling refrigerant in the supercooling refrigerant circuit (220) is used as the ambient condition of the supercooling heat exchanger (210). In this case, although not shown, a pressure sensor as pressure detecting means is provided on the discharge side of the supercooling compressor (221), and the detected pressure is input to the controller (240). In the controller (240), the target liquid refrigerant outlet temperature Eom is set based on the detected pressure. That is, it is estimated that the load increases as the high pressure of the supercooling refrigerant increases, and the target liquid refrigerant outlet temperature Eom is set to be low.

-Modification 6
In the refrigeration apparatus (10) of Modification 6, the pressure difference between the high pressure and the low pressure of the supercooling refrigerant in the supercooling refrigerant circuit (220) is used as the ambient condition of the supercooling heat exchanger (210). It is done. In this case, although not shown, pressure sensors as pressure detecting means are provided on the discharge side and suction side of the supercooling compressor (221), and these detected pressures are input to the controller (240). In the controller (240), the target liquid refrigerant outlet temperature Eom is set based on the pressure difference between the detected pressures. That is, it is estimated that the load increases as the pressure difference increases, and the target liquid refrigerant outlet temperature Eom is set to be low.

<< Embodiment 2 of the Invention >>
In the refrigeration apparatus (10) of the second embodiment, the first embodiment directly increases the operating frequency of the supercooling compressor (221) to increase the power consumption of the supercooling compressor (221). Instead, the power consumption of the subcooling refrigerant circuit (220) is increased by increasing the operating frequency of the outdoor fan (230) of the subcooling outdoor heat exchanger (222). . That is, in this embodiment, even if the load increases, the operating frequency of the supercooling compressor (221) is not changed.

  Specifically, when the operating frequency of the outdoor fan (230) is increased, the flow rate of the supercooling refrigerant in the supercooling heat exchanger (210) is increased, and the cooling capacity is increased. That is, when the operating frequency of the outdoor fan (230) is increased, the high-pressure pressure of the supercooling refrigerant in the supercooling refrigerant circuit (220) is reduced, and the volume efficiency of the supercooling compressor (221) is improved. The circulation amount of the refrigerant increases. Therefore, the liquid refrigerant outlet temperature Tout decreases. As a result, the power consumption of the outdoor fan (230) increases, and the power consumption of the supercooling refrigerant circuit (220) increases preferentially.

  In the case of this embodiment, the control operation of the controller (240) is as follows. In step S2 of FIG. 4, it is determined whether the frequency of the outdoor fan (230) is the lowest frequency. And if it is the lowest frequency, it will be complete | finished, and if it is not the lowest frequency, it will move to step S3. In step S3, the frequency of the outdoor fan (230) is decreased by a predetermined step, and the process ends.

  On the other hand, in step S4, it is determined whether the frequency of the outdoor fan (230) is the highest frequency. And if it is the highest frequency, it will be complete | finished, and if it is not the highest frequency, it will move to step S5. In step S5, the frequency of the supercooling compressor (221) is increased by a predetermined step, and the process ends. The controller (240) performs the above routine every 30 seconds.

  As described above, when the load on the refrigeration apparatus (10) increases due to the increase in the outside air temperature Ta, the controller (240) adjusts the target liquid refrigerant outlet temperature Eom to give priority to the operating capacity of the outdoor fan (230). Can be increased. As a result, the power consumption of the supercooling refrigerant circuit (220) is preferentially increased, and the increase in power consumption of the entire refrigeration apparatus (10) is suppressed. Other configurations, operations, and effects are the same as those of the first embodiment.

<< Embodiment 3 of the Invention >>
Although the refrigeration apparatus (10) of the third embodiment is not shown, in the first embodiment, the cooling fluid circuit is configured by a refrigerant circuit in which the supercooling refrigerant circulates. It is configured by a circuit. Specifically, the cooling water circuit includes a supercooling heat exchanger (210) and a pump, and the cooling water of the cooling tower is conveyed to the supercooling heat exchanger (210) by the pump. In the supercooling heat exchanger (210), the cooling water exchanges heat with the refrigerant in the refrigerant passage (205) to cool the refrigerant. That is, in the cooling fluid circuit of the present embodiment, the cooling water flows as the cooling fluid.

  In this case, the controller (240) increases the operating capacity of the pump so that the liquid refrigerant outlet temperature Tout becomes the target liquid refrigerant outlet temperature Eom when the load of the refrigeration apparatus (10) increases. As a result, the power consumption of the pump increases, the power consumption related to the cooling water circuit preferentially increases, and the amount of increase in power consumption of the entire refrigeration apparatus (10) is suppressed. Other configurations, operations, and effects are the same as those of the first embodiment.

  In addition, the above embodiment and its modification are essentially preferable illustrations, Comprising: It does not intend restrict | limiting the range of this invention, its application thing, or its use.

  As described above, the present invention is useful for a refrigeration apparatus that supercools a refrigerant with a supercooling heat exchanger.

It is a piping system diagram which shows the structure of the freezing apparatus provided with the supercooling unit. It is a piping system diagram which shows the operation | movement at the time of air_conditionaing | cooling operation of a freezing apparatus. It is a piping system diagram which shows the operation | movement at the time of heating operation of a freezing apparatus. It is a graph which shows target liquid refrigerant | coolant exit temperature. It is a flowchart which shows the operation control of a controller.

Explanation of symbols

10 Refrigeration equipment
20 Refrigerant circuit
41 Variable capacity compressor (heat source side compressor)
42 1st fixed capacity compressor (heat source side compressor)
43 2nd fixed capacity compressor (heat source side compressor)
101 Air conditioning heat exchanger (use side heat exchanger)
111 Refrigerated heat exchanger (use side heat exchanger)
131 Refrigeration heat exchanger (use side heat exchanger)
210 Heat exchanger for supercooling
220 Supercooling refrigerant circuit (cooling fluid circuit)
221 Supercooling compressor (pump mechanism)
222 Outdoor heat exchanger for supercooling (heat source side heat exchanger)
230 Outdoor fan (fan)
240 controller (control means)

Claims (9)

  1. A refrigerant circuit (20) having a use side heat exchanger (101, 111, 131) and a heat source side compressor (41, 42, 43), and performing a vapor compression refrigeration cycle by circulating the refrigerant;
    A cooling fluid circuit (220) having a supercooling heat exchanger (210) and a pump mechanism (221) for conveying the cooling fluid to the supercooling heat exchanger (210),
    A refrigerating apparatus that supercools the refrigerant supplied to the use side heat exchanger (101, 111, 131) with a cooling fluid in the supercooling heat exchanger (210),
    Control means (240) for controlling power consumption related to the refrigerant circuit (20) and power consumption related to the cooling fluid circuit (220);
    The control means (240) controls the power consumption of the cooling fluid circuit (220) so that the temperature of the refrigerant at the outlet of the supercooling heat exchanger (210) becomes a target value, and the load increases. ambient conditions during the above refrigerant circuit (20) heat exchanger for supercooling the target value as the power consumption is increased large related to the power consumption the cooling fluid circuit without increasing the (220) about the (210) A refrigeration apparatus configured to be set based on the above.
  2. In claim 1 ,
    The refrigeration apparatus, wherein the ambient condition of the supercooling heat exchanger (210) is an outside air temperature.
  3. In claim 1 ,
    The refrigeration apparatus, wherein the ambient condition of the supercooling heat exchanger (210) is a degree of supercooling of the refrigerant in the refrigerant circuit (20) in the supercooling heat exchanger (210).
  4. In claim 1 ,
    The refrigeration apparatus, wherein the ambient condition of the supercooling heat exchanger (210) is a refrigerant flow rate of the refrigerant circuit (20) flowing through the supercooling heat exchanger (210).
  5. In claim 1 ,
    The ambient conditions of the supercooling heat exchanger (210) are the cooling fluid circuit (220 before and after supercooling the refrigerant of the refrigerant circuit (20) in the supercooling heat exchanger (210)). ) Is a temperature difference of the cooling fluid.
  6. In claim 1 ,
    The refrigeration apparatus, wherein the ambient condition of the supercooling heat exchanger (210) is a flow rate of the cooling fluid in the cooling fluid circuit (220) flowing through the supercooling heat exchanger (210).
  7. In claim 1 ,
    The cooling fluid circuit has a supercooling compressor (221) and a heat source side heat exchanger (222) as a pump mechanism, and a supercooling refrigerant as a cooling fluid circulates to form a vapor compression refrigeration. A refrigerant circuit for supercooling (220) that performs a cycle;
    The refrigeration apparatus wherein the ambient condition of the supercooling heat exchanger (210) is a high pressure of the supercooling refrigerant in the supercooling refrigerant circuit (220).
  8. In claim 1 ,
    The cooling fluid circuit has a supercooling compressor (221) and a heat source side heat exchanger (222) as a pump mechanism, and a supercooling refrigerant as a cooling fluid circulates to form a vapor compression refrigeration. A refrigerant circuit for supercooling (220) that performs a cycle;
    The refrigeration apparatus, wherein the ambient condition of the supercooling heat exchanger (210) is a pressure difference between the high pressure and the low pressure of the supercooling refrigerant in the supercooling refrigerant circuit (220).
  9. In claim 2 ,
    The said control means (240) is comprised so that the said target value may be made low as external temperature becomes high, The freezing apparatus characterized by the above-mentioned.
JP2005223726A 2004-12-28 2005-08-02 Refrigeration equipment Expired - Fee Related JP3861912B2 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
JP2004379512 2004-12-28
JP2005223726A JP3861912B2 (en) 2004-12-28 2005-08-02 Refrigeration equipment

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2005223726A JP3861912B2 (en) 2004-12-28 2005-08-02 Refrigeration equipment

Publications (2)

Publication Number Publication Date
JP2006207990A JP2006207990A (en) 2006-08-10
JP3861912B2 true JP3861912B2 (en) 2006-12-27

Family

ID=36965048

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2005223726A Expired - Fee Related JP3861912B2 (en) 2004-12-28 2005-08-02 Refrigeration equipment

Country Status (1)

Country Link
JP (1) JP3861912B2 (en)

Families Citing this family (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008082677A (en) * 2006-09-29 2008-04-10 Sanyo Electric Co Ltd Supercooling device
JP2008082678A (en) * 2006-09-29 2008-04-10 Sanyo Electric Co Ltd Supercooling device
JP2008082675A (en) * 2006-09-29 2008-04-10 Sanyo Electric Co Ltd Supercooling device
JP2008082676A (en) * 2006-09-29 2008-04-10 Sanyo Electric Co Ltd Supercooling device
JP2008180429A (en) * 2007-01-24 2008-08-07 Daikin Ind Ltd Refrigeration system
JP5228661B2 (en) * 2008-07-17 2013-07-03 ダイキン工業株式会社 Refrigeration equipment
JP2008309476A (en) * 2008-09-29 2008-12-25 Sanyo Electric Co Ltd Supercooling device
JP2008309475A (en) * 2008-09-29 2008-12-25 Sanyo Electric Co Ltd Supercooling device
JP2008309472A (en) * 2008-09-29 2008-12-25 Sanyo Electric Co Ltd Supercooling device
JP2008309470A (en) * 2008-09-29 2008-12-25 Sanyo Electric Co Ltd Supercooling device
JP2008309485A (en) * 2008-09-29 2008-12-25 Sanyo Electric Co Ltd Supercooling device
JP2009024997A (en) * 2008-09-29 2009-02-05 Sanyo Electric Co Ltd Supercooling device
JP2009041904A (en) * 2008-09-29 2009-02-26 Sanyo Electric Co Ltd Supercooling device
JP2009036508A (en) * 2008-09-29 2009-02-19 Sanyo Electric Co Ltd Supercooling system
JP2009002645A (en) * 2008-09-29 2009-01-08 Sanyo Electric Co Ltd Supercooling device
JP5940294B2 (en) * 2011-12-22 2016-06-29 中部電力株式会社 Refrigeration equipment

Also Published As

Publication number Publication date
JP2006207990A (en) 2006-08-10

Similar Documents

Publication Publication Date Title
JP4459776B2 (en) Heat pump device and outdoor unit of heat pump device
JP4670329B2 (en) Refrigeration air conditioner, operation control method of refrigeration air conditioner, refrigerant amount control method of refrigeration air conditioner
US9506674B2 (en) Air conditioner including a bypass pipeline for a defrosting operation
CN1186576C (en) Refrigerator
JP3953029B2 (en) Refrigeration equipment
JP4651627B2 (en) Refrigeration air conditioner
KR100552096B1 (en) Refrigerating device
JP4740984B2 (en) Refrigeration air conditioner
JP5430667B2 (en) Heat pump equipment
CN100416184C (en) Refrigeration equipment
JP4906894B2 (en) Heat pump device and outdoor unit of heat pump device
KR20090115173A (en) Refrigeration device
KR100648457B1 (en) Freezing device
KR101201062B1 (en) Refrigeration device
KR100833441B1 (en) Freezing apparatus
JP4096934B2 (en) Refrigeration equipment
ES2366535T3 (en) Air conditioner.
US7028502B2 (en) Refrigeration equipment
US20080229782A1 (en) Refrigerating Apparatus
WO2005024313A1 (en) Freezer device
JP5040104B2 (en) Refrigeration equipment
CN105570993B (en) Air-conditioning equipment
JP5120056B2 (en) Refrigeration equipment
JP4465889B2 (en) Refrigeration equipment
AU2005252958B2 (en) Subcooling apparatus

Legal Events

Date Code Title Description
TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20060905

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20060918

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20091006

Year of fee payment: 3

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20101006

Year of fee payment: 4

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20111006

Year of fee payment: 5

LAPS Cancellation because of no payment of annual fees