WO2005121654A1

WO2005121654A1 - Supercooling apparatus

Info

Publication number: WO2005121654A1
Application number: PCT/JP2005/010584
Authority: WO
Inventors: Masaaki Takegami; Kenji Tanimoto; Satoru Sakae; Iwao Shinohara; Azuma Kondo
Original assignee: Daikin Industries, Ltd.
Priority date: 2004-06-11
Filing date: 2005-06-09
Publication date: 2005-12-22
Also published as: EP1674806A1; US20070022777A1; KR100764339B1; KR20060060734A; EP1674806A4; CN100417875C; AU2005252958B2; AU2005252958A1; CN1842680A

Abstract

A supercooling apparatus, comprising a supercooling unit (200). In the supercooling unit, a refrigerant passage (205) is connected to the liquid side communication pipes (21, 22) of a refrigerating device (10). When a supercooling compressor (221) is operated, a supercooling refrigerant is circulated in a supercooling refrigerant circuit (220), a refrigerating cycle is performed, and the refrigerant of the refrigerating device (10) flowing in the refrigerant passage (205) is cooled. The detected values of a suction pressure sensor (234) and a refrigerant temperature sensor (236) are inputted into the controller (240) of the supercooling unit (200). The controller (240) performs the operating control of the supercooling compressor (221) based on information obtained in the supercooling unit (200) by utilizing input signals from these sensors (234, 236). Thus, the controller can perform the operating control of the supercooling compressor (221) without exchanging signals with the refrigerating device to be installed.

Description

Specification

Subcooling device

Technical field

[0001] The present invention relates to a subcooling device that is attached to a refrigeration system having a heat source unit and a utilization unit and cools a refrigerant sent from the heat source unit to the utilization unit through a liquid-side communication pipe.

Background art

[0002] Conventionally, a subcooling device that is attached to a refrigeration system for the purpose of increasing the cooling capacity and cools a refrigerant of the refrigeration system sent from a heat source unit to a use unit is known.

[0003] For example, the supercooling device disclosed in Patent Document 1 is attached to an air conditioner provided with an outdoor unit and an indoor unit. Specifically, the supercooling device is provided in the middle of the liquid-side connecting pipe connecting the outdoor unit and the indoor unit, and includes a supercooling refrigerant circuit. This supercooling device circulates a refrigerant in a subcooling refrigerant circuit to perform a cooling / freezing cycle, and cools the refrigerant of the air conditioner sent from the liquid-side communication pipe by an evaporator in the subcooling refrigerant circuit. The supercooling device cools the liquid refrigerant sent from the outdoor unit of the air conditioner to the indoor unit, and lowers the enthalpy of the liquid refrigerant sent to the indoor unit, thereby improving the cooling capacity.

[0004] As described above, the supercooling device is for increasing the cooling capacity of a refrigerating device such as an air conditioner by assisting the device. For this reason, it is meaningless to operate only the subcooling device while the refrigerating device is stopped. It is also meaningless to operate the supercooling device while the refrigeration device operates as a heat pump, as in the heating operation of an air conditioner. in this way

In order to determine whether or not to operate the supercooling device, it is necessary to know the operating state of the refrigeration system equipped with the supercooling device.

[0005] Therefore, in the conventional supercooling device disclosed in Patent Document 1, the control unit of the supercooling device is connected to the control unit of the air conditioner to constitute one control system. A signal indicating the operation state of the air conditioner is input to the control unit of the supercooling device from the control unit of the air conditioner. In this subcooling device, the signal input from the control unit of the air conditioner is The operation control is performed based on the signal.

Patent Document 1: JP-A-10-185333

Disclosure of the invention

Problems to be solved by the invention

[0006] As described above, the conventional supercooling device exchanges signals with the refrigerating device to which it is attached. For this reason, when attaching the subcooling device to the refrigeration unit, wiring work for transmitting signals transmitted and received between the two is required, and there has been a problem that the installation work of the supercooling device is complicated. In addition, there is a possibility that erroneous wiring may occur when the supercooling device is installed, and there is a possibility that a trouble due to such an error in the installation work may be caused.

[0007] The present invention has been made in view of the advantages thereof, and an object of the present invention is to control the operation of a supercooling device without transmitting and receiving signals to and from a refrigeration device to be mounted. In addition to simplifying the installation work of the supercooling device, it aims to prevent troubles caused by human error during the installation work.

Means for solving the problem

[0008] The first invention provides a refrigeration apparatus (10) that circulates a heat source-side refrigerant between a heat source unit (11) and a use unit (12, 13, 14) connected by a communication pipe to perform a refrigeration cycle. It is intended for a supercooling device which is attached to the heat source unit (11) and cools the refrigerant on the heat source side of the refrigerating device (10) sent to the power utilization units (12, 13, 14). A refrigerant passage (205) connected to the liquid-side communication pipe (21, 22) of the refrigeration system (10), a cooling fluid circuit (220) through which a cooling fluid flows, and the refrigerant passage (205) The supercooling heat exchanger (210) for exchanging the heat source side refrigerant in the cooling fluid with the cooling fluid for cooling, and the flow state of the cooling fluid in the cooling fluid circuit (220) are defined by the refrigerant. Control means (240) for controlling according to the flow state of the heat-source-side refrigerant in the passage (205).

[0009] In the first aspect, in the refrigeration system (10) to which the subcooling device (200) is attached, the refrigerant flows between the heat source unit (11) and the utilization units (12, 13, 14) through the communication pipe. Come and go. The refrigerant passage (205) of the subcooling device (200) is connected to the liquid-side connection pipe (21, 22) of the refrigerating device (10), and the heat source-side refrigerant of the refrigerating device (10) flows through the inside. In the cooling fluid circuit (220) of the supercooling device (200), a cooling fluid flows. Subcooling heat exchangers (210) In, the heat source side refrigerant flowing in the refrigerant passage (205) is cooled by exchanging heat with the cooling fluid.

[0010] The subcooling device (200) of the present invention is for assisting the operation of the refrigeration device (10). For this reason, the operation of the subcooling device (200) is required only while the refrigeration device (10) is operating

It is meaningless to operate only the subcooling device (200) while the refrigerating device (10) is stopped. Further, the supercooling device ( ₂₀₀ ) of the present invention is for increasing the cooling capacity of the utilization units ( ₁₂ , ₁₃ , ₁₄ ). For this reason, for example, in a state where the refrigeration unit (10) functions as a heat pump, even if the subcooling unit (200) is operated, almost no profit is expected. As described above, the subcooling device (200) may or may not be operated depending on the operation state of the refrigeration device (10).

[0011] In contrast, in the supercooling device (200) of the present invention, the control means (240) controls the flow state of the cooling fluid in the cooling fluid circuit (220). At this time, the control means (240) controls the flow state of the cooling fluid in accordance with the flow state of the heat source side refrigerant in the refrigerant passage (205). In the refrigerant passage (205), the heat-source-side refrigerant flowing between the heat-source unit (11) and the utilization unit (12, 13, 14) passes through the liquid-side connecting pipe (21, 22). ing. Therefore, it is possible to determine the operation state of the refrigeration system (10) based on the state of circulation of the refrigerant in the refrigerant passage (205). Therefore, the control means (240) of the subcooling device (200) determines the flow state of the heat source side refrigerant in the refrigerant passage (205) that does not receive a signal relating to the operation state of the refrigeration device (10) from the refrigeration device (10). The flow state of the cooling fluid in the cooling fluid circuit (220) is controlled according to the condition.

[0012] In a second aspect based on the first aspect, the cooling fluid circuit includes a subcooling refrigerant circuit (220), and the subcooling refrigerant circuit (220) includes a subcooling refrigerant circuit (220). And a refrigeration cycle by circulating a supercooling refrigerant as a cooling fluid.

[0013] In the second invention, in the subcooling refrigerant circuit (220) of the subcooling device (200), a refrigeration cycle is performed by circulating the subcooling refrigerant. In the subcooling heat exchanger (210), the heat source side refrigerant flowing in the refrigerant passage (205) exchanges heat with the subcooling refrigerant. In the supercooling heat exchanger (210), the supercooling refrigerant also absorbs heat from the heat source side refrigerant and evaporates. The heat source side refrigerant is cooled.

[0014] In a third aspect based on the second aspect, the control means (240) controls the operation of the subcooling compressor (221) to thereby control the subcooling refrigerant circuit (220). It is configured to control the circulation state of the supercooling refrigerant in the above.

[0015] In the third invention, when the control means (240) adjusts the operating capacity of the subcooling compressor (221), the circulation amount of the subcooling refrigerant in the subcooling refrigerant circuit (220) is increased. Change. Accordingly, if the operation of the supercooling compressor (221) is controlled, the circulation state of the supercooling refrigerant in the supercooling refrigerant circuit (220) is thereby controlled.

[0016] In a fourth aspect based on the third aspect, the control means (240) is configured to control the flow direction of the heat-source-side refrigerant in the refrigerant passage (205) during operation of the subcooling compressor (221). The flow of the heat source side refrigerant in the refrigerant passage (205) is detected as the flow state of the heat source side refrigerant, and the heat source unit (11) power utilization unit (12, 13, 14) is detected in the refrigerant passage (205). )) When the refrigerant is flowing toward the heat source side, the operation of the subcooling compressor (221) is continued, and the inside of the refrigerant passage (205) is directed from the utilization units (12, 13, 14) to the heat source unit (11). When the heat source side refrigerant flows in the refrigerant passage (205) and the heat source side refrigerant flows in the refrigerant passage (205), the supercooling compressor (221) is stopped. .

[0017] In the fourth aspect, the control means (240) detects the state of flow of the refrigerant during operation of the subcooling compressor (221). Specifically, the control means (240) detects the flow direction of the refrigerant in the refrigerant passage (205) and the presence or absence of the refrigerant flow in the refrigerant passage (205) as the refrigerant flow state.

[0018] The control means (240) of the present invention controls the operation of the subcooling compressor (221) based on the detected refrigerant flow state. In a state in which the refrigerant flows in the refrigerant passage (205) toward the heat source unit (11) and the use unit (12, 13, 14), the refrigeration unit (10) is operated by the use unit (12, 13, 14). It can be determined that the operation of cooling the object is being performed. Therefore, in this state, the control means (240) continues the operation of the subcooling compressor (221), and the subcooling device (200) moves from the heat source unit (11) to the utilization unit (12, 13, 14). Direction Cools the refrigerant. On the other hand, in a state where the refrigerant flows from the utilization units (12, 13, 14) to the heat source unit (11) in the refrigerant passage (205), or in a state where the refrigerant is not flowing in the refrigerant passage (205), the refrigeration is not performed. Equipment (10) used It can be determined that the operation of cooling the object is not performed in the units (12, 13, 14). Therefore, in this state, the control means (240) stops the operation of the subcooling compressor (221) and avoids useless operation of the subcooling device (200).

[0019] In a fifth aspect based on the fourth aspect, the control means (240) is configured such that when a predetermined time elapses from the time when the supercooling compressor (221) is stopped, the supercooling compressor (240) 221).

[0020] In the fifth aspect, the control means (240) measures an elapsed time from a point in time when the supercooling compressor (221) is stopped. Then, the control means (240) activates the subcooling compressor (221) when a predetermined time has elapsed since the supercooling compressor (221) was stopped. The control means (240) detects the flow state of the refrigerant in the refrigerant passage (205) after the activation of the subcooling compressor (221), and operates the subcooling compressor (221) accordingly. Is to be continued or the supercooling compressor (221) is stopped.

[0021] In a sixth aspect based on the third, fourth, or fifth aspect, the utilization unit (12, 13, 14) of the refrigerant passage (205) is more than the supercooling heat exchanger (210). While a refrigerant temperature detecting means (236) for detecting the temperature of the heat source side refrigerant in the closer part is provided, the control means (240) controls the refrigerant temperature from the time when the supercooling compressor (221) is started. It is configured to determine the circulation state of the heat source side refrigerant based on a change in the detection value of the detection means (236).

[0022] In the sixth aspect, the subcooling device (200) is provided with the refrigerant temperature detecting means (236).

The refrigerant temperature detecting means (236) detects the refrigerant temperature in a portion of the refrigerant passage (205) closer to the use unit (12, 13, 14) than the supercooling heat exchanger (210).

[0023] The control means (240) of the present invention controls the refrigerant passage (205) based on a change in the detected value of the refrigerant temperature detecting means (236) from the time when the subcooling compressor (221) is started. To determine the state of circulation of the refrigerant. For example, in a state where the detection value of the refrigerant temperature detecting means (236) decreases as time elapses from the start of the supercooling compressor (221), the refrigerant cooled by the supercooling heat exchanger (210) It can be determined that the temperature of the refrigerant is detected by the refrigerant temperature detecting means (236), and as a result, the refrigerant flows in the refrigerant passage (205) toward the utilization unit (12, 13, 14) due to the heat source unit (11). Can be determined to be. The subcooling compressor (221) In a state where the detected value of the refrigerant temperature detecting means (236) does not change even after a lapse of time from the start, the temperature of the refrigerant before flowing into the supercooling heat exchanger (210) is changed to the refrigerant temperature detecting means (236). It can be determined that no refrigerant is flowing in the refrigerant detected in the above or in the refrigerant passage (205).

[0024] In a seventh aspect based on the third, fourth, or fifth aspect, the utilization unit (12, 13, 14) of the refrigerant passage (205) is more than the supercooling heat exchanger (210). Refrigerant temperature detecting means (236) for detecting the temperature of the heat source side refrigerant in the closer part; and evaporating temperature detecting means (e.g., evaporating temperature of the subcooling refrigerant in the supercooling heat exchanger (210)). 234), while the control means (240) determines the circulation state of the heat source side refrigerant based on the detection value of the refrigerant temperature detection means (236) and the detection value of the evaporation temperature detection means (234). It is configured to make a decision.

[0025] In the seventh aspect, the subcooling device (200) is provided with the refrigerant temperature detecting means (236) and the evaporating temperature detecting means (234). The refrigerant temperature detecting means (236) detects the refrigerant temperature in a portion of the refrigerant passage (205) closer to the use unit (12, 13, 14) than the supercooling heat exchanger (210). The evaporating temperature detecting means (234) detects an evaporating temperature of the subcooling refrigerant in the subcooling heat exchanger (210).

[0026] The control means (240) of the present invention, based on the detection value of the refrigerant temperature detection means (236) and the detection value of the evaporation temperature detection means (234), determines the state of flow of the refrigerant in the refrigerant passage (205). Judge. For example, if the detected value of the refrigerant temperature detecting means (236) is slightly higher than the detected value of the evaporating temperature detecting means (234), the temperature of the refrigerant cooled by the supercooling heat exchanger (210) becomes higher. It can be determined that the temperature is detected by the temperature detecting means (236). As a result, it is determined that the refrigerant is flowing in the refrigerant passage (205) toward the heat source unit (11) and the power utilization units (12, 13, 14). it can. If the detected value of the refrigerant temperature detecting means (236) is significantly higher than the detected value of the evaporating temperature detecting means (234), the temperature of the refrigerant before flowing into the supercooling heat exchanger (210) is increased. Can be determined as the force detected by the refrigerant temperature detecting means (236) or that the refrigerant is not flowing in the refrigerant passage (205).

[0027] In an eighth aspect based on the third, fourth or fifth aspect, the utilization unit (12, 13, 14) of the refrigerant passage (205) is more than the supercooling heat exchanger (210). Heat source side cooling in the closer part A first refrigerant temperature detecting means (237) for detecting the temperature of the medium; and a temperature of the heat source side refrigerant in a portion of the refrigerant passage (205) closer to the heat source unit (11) than the supercooling heat exchanger (210). A second refrigerant temperature detecting means (238) for detecting the temperature, while the control means (240) includes a detection value of the first refrigerant temperature detecting means (237) and the second refrigerant temperature detecting means (238). The flow state of the heat-source-side refrigerant is determined based on the detected value.

[0028] In the eighth aspect, the subcooling device (200) is provided with the first refrigerant temperature detecting means (237) and the second refrigerant temperature detecting means (238). The first refrigerant temperature detecting means (237) detects the refrigerant temperature in a portion of the refrigerant passage (205) closer to the use unit (12, 13, 14) than the supercooling heat exchanger (210). The second refrigerant temperature detecting means (238) detects the refrigerant temperature in a portion of the refrigerant passage (205) closer to the heat source unit (11) than the subcooling heat exchanger (210).

[0029] The control means (240) of the present invention controls the refrigerant passage (205) based on the detection value of the first refrigerant temperature detection means (237) and the detection value of the second refrigerant temperature detection means (238). Judge the state of refrigerant flow. For example, when the detected value of the first refrigerant temperature detecting means (237) is sufficiently lower than the detected value of the second refrigerant temperature detecting means (238), the utilization units (12, 13, 13) are transmitted from the heat source unit (11). It can be determined that the refrigerant working toward 14) is cooled by the supercooling heat exchanger (210). Conversely, when the detection value of the first refrigerant temperature detecting means (237) is higher than the detection value of the second refrigerant temperature detecting means (238), the usage unit (12, 13, 14) transfers to the heat source unit (11). It can be determined that the directional coolant is being cooled by the supercooling heat exchanger (210). In addition, in a state where the detection value of the first refrigerant temperature detecting means (237) and the detection value of the second refrigerant temperature detecting means (238) are almost the same, it is necessary that the refrigerant does not circulate in the refrigerant passage (205). I can judge.

[0030] In a ninth aspect based on the first, second or third aspect, the refrigerant passage (205) is provided with a flow meter (251) for detecting a flow rate of the heat source side refrigerant, The means (240) uses the detected value of the flow meter (251) as a flow state display value indicating the flow state of the heat source side refrigerant, and the cooling fluid is flowing in the cooling fluid circuit (220). In the state, whether to continue or stop the flow of the cooling fluid is determined based on the flow state display value.

[0031] In the ninth aspect, the detection value of the flow meter (251) is input to the control means (240). Refrigerant The flow state of the heat source side refrigerant in the passage (205) can be determined based on the detection value of the flow meter (251). Therefore, the control means (240) uses the detected value of the flow meter (251) as a flow state display value, and based on the flow state display value, the flow state of the cooling fluid in the cooling fluid circuit (220). Control.

[0032] In a tenth aspect based on the first, second, or third aspect, the utilization unit (12, 13, 14, 14) of the refrigerant passage (205) is more than the supercooling heat exchanger (210). ) A first refrigerant temperature detecting means (237) for detecting the temperature of the refrigerant on the heat source side in a portion closer to the heat source unit (11) than the supercooling heat exchanger (210) in the refrigerant passage (205); A second refrigerant temperature detecting means (238) for detecting the temperature of the heat-source-side refrigerant in the portion, while the control means (240) is configured to detect the detected value of the first refrigerant temperature detecting means (237) and the second refrigerant temperature. The difference from the temperature detection means (238) is used as a flow state display value indicating the flow state of the heat source side refrigerant, and when the cooling fluid is flowing in the cooling fluid circuit (220), the cooling is performed. That is configured to determine whether to continue or stop the flow of the working fluid based on the above-mentioned flow state display value A.

[0033] In the tenth aspect, the detection values of the first refrigerant temperature detecting means (237) and the second refrigerant temperature detecting means (238) are input to the control means (240). By comparing the detected value of the first refrigerant temperature detecting means (237) with the detected value of the second refrigerant temperature detecting means (238), it is possible to determine the flow state of the heat source side refrigerant in the refrigerant passage (205). For example, if the detected value of the first refrigerant temperature detecting means (237) is lower than the detected value of the second refrigerant temperature detecting means (238), the heat source unit (11) and the power utilization unit (12, It can be determined that the heat source side refrigerant is circulating toward (13, 14). Otherwise, the force or heat of the heat application side refrigerant flows in the refrigerant passage (205) from the utilization units (12, 13, 14) to the heat source unit (11). You can judge that you have not. Therefore, the control means (240) uses the difference between the detection value of the first refrigerant temperature detection means (237) and the detection value of the second refrigerant temperature detection means (238) as a flow state display value. The circulation state of the cooling fluid in the cooling fluid circuit (220) is controlled based on the displayed value.

According to an eleventh invention, in the first, second, or third invention, the utilization unit (12, 13, 14, 14) of the refrigerant passage (205) is replaced by the supercooling heat exchanger (210). ) Heat source side in the closer part While the refrigerant temperature detecting means (236) for detecting the temperature of the refrigerant is provided, the control means (240) displays a change in the value detected by the refrigerant temperature detecting means (236) in a flow state display indicating the flow state of the heat source side refrigerant. In the state where the cooling fluid is flowing in the cooling fluid circuit (220), whether to continue or stop the flow of the cooling fluid is determined based on the flow state display value. It is configured in.

[0035] In the eleventh aspect, the detection value of the refrigerant temperature detection means (236) is input to the control means (240). By monitoring the change in the detected value of the refrigerant temperature detecting means (236), the flow state of the heat source side refrigerant in the refrigerant passage (205) can be determined. For example, if the detected value of the refrigerant temperature detecting means (236) decreases while the cooling fluid is flowing, the heat source unit (11) and the power utilization units (12, 13, 13) It can be determined that the heat source side refrigerant is circulating toward 14). If not, the refrigerant on the refrigerant passage (205) flows toward the utilization unit (12, 13, 14) toward the heat source unit (11). It can be determined that the medium is not flowing. Therefore, the control means (240) uses the detected value of the refrigerant temperature detecting means (236) as the flow state display value, and based on the flow state display value, the flow of the cooling fluid in the cooling fluid circuit (220). Control the state.

[0036] In a twelfth aspect based on the first, second or third aspect, the cooling fluid circuit (220) is provided with a cooling fluid at an inlet of a supercooling heat exchanger (210). An inlet fluid temperature detecting means (252) for detecting the temperature and an outlet fluid temperature detecting means (253) for detecting the temperature of the cooling fluid at the outlet of the supercooling heat exchanger (210) are provided. On the other hand, the control means (240) indicates the difference between the detected value of the inlet-side fluid temperature detecting means (252) and the detected value of the outlet-side fluid temperature detecting means (253) to indicate the flow state of the heat source side refrigerant. The flow state display value is used as the flow state display value to determine whether to continue or stop the flow of the cooling fluid while the cooling fluid is flowing in the cooling fluid circuit (220). It is configured to be determined on the basis of this.

[0037] In the twelfth aspect, the detected values of the inlet fluid temperature detecting means (252) and the outlet fluid temperature detecting means (253) are input to the control means (240). By comparing the detected value of the inlet fluid temperature detecting means (252) with the detected value of the inlet fluid temperature detecting means (252), it is possible to determine the flow state of the heat source side refrigerant in the refrigerant passage (205). For example, inlet fluid temperature If the detected value of the detecting means (252) is higher than the detected value of the inlet-side fluid temperature detecting means (252), the inside of the refrigerant passage (205) is directed to the heat source unit (11) and the power utilization unit (12, 13, 14). Thus, it can be determined that the heat source side refrigerant is flowing. Otherwise, the force flowing through the refrigerant passage (205) from the utilization units (12, 13, 14) toward the heat source unit (11), or It can be determined that the refrigerant is not flowing. Therefore, the control means (240) uses the difference between the detected value of the inlet-side fluid temperature detecting means (252) and the detected value of the outlet-side fluid temperature detecting means (253) as the flow state display value. The flow state of the cooling fluid in the cooling fluid circuit (220) is controlled on the basis of the above.

[0038] In a thirteenth aspect based on the second or third aspect, the evaporating pressure of the subcooling refrigerant in the subcooling heat exchanger (210) is provided in the subcooling refrigerant circuit (220). While the evaporating pressure detecting means for detecting (234) is provided, the control means (240) uses the detected value of the evaporating pressure detecting means (234) as a flow state display value indicating the flow state of the heat source side refrigerant, In a state where the subcooling refrigerant is circulating in the subcooling refrigerant circuit (220), it is configured to determine whether to continue or stop the circulation of the supercooling refrigerant on the basis of the flow state display value. Things.

[0039] In the thirteenth aspect, the detected value of the evaporating pressure detecting means (234) is input to the control means (240). By monitoring the change in the detected value of the evaporating pressure detecting means (234), it is possible to determine the flow state of the heat source side refrigerant in the refrigerant passage (205). For example, if the detected value of the evaporating pressure detecting means (234) is more than a certain level while the subcooling refrigerant is circulating, it can be determined that the heat source side refrigerant is flowing in the refrigerant passage (205). . Otherwise, it can be determined that the enthusiasm-side refrigerant is not flowing in the refrigerant passage (205). Therefore, the control means (240) uses the detected value of the evaporating pressure detecting means (234) as the flow state display value, and based on the flow state display value, determines the excess in the subcooling refrigerant circuit (220). Controls the flow of the cooling refrigerant.

[0040] A fourteenth invention is directed to the second or third invention, wherein a portion of the refrigerant passage (205) closer to the utilization unit (12, 13, 14) than the subcooling heat exchanger (210). A refrigerant temperature detecting means (236) for detecting the temperature of the heat source side refrigerant in (2), and an evaporating temperature detecting means (234) for detecting the evaporating temperature of the subcooling refrigerant in the subcooling heat exchanger (210). On the other hand The control means (240) uses the difference between the detected value of the refrigerant temperature detecting means (236) and the detected value of the evaporation temperature detecting means (234) as a flow state display value indicating the flow state of the heat source side refrigerant. In a state where the subcooling refrigerant is circulating in the subcooling refrigerant circuit (220), whether to continue or stop the circulation of the supercooling refrigerant is determined based on the flow state display value. It is configured to determine.

[0041] In the fourteenth invention, the detected values of the refrigerant temperature detecting means (236) and the evaporation temperature detecting means (234) are input to the control means (240). By comparing the detection value of the refrigerant temperature detection means (236) with the detection value of the evaporation temperature detection means (234), it is possible to determine the flow state of the heat source side refrigerant in the refrigerant passage (205). For example, if the difference between the detected value of the refrigerant temperature detecting means (236) and the detected value of the evaporating temperature detecting means (234) is within a predetermined value (for example, about 10 ° C), the heat source in the refrigerant passage (205) is heated. Unit (11) power It can be determined that the heat source side refrigerant is circulating toward the utilization units (12, 13, 14). Otherwise, the refrigerant in the refrigerant passage (205) flows toward the utilization unit (12, 13, 14) toward the heat source unit (11). It can be determined that is not flowing. Therefore, the control means (240) uses the difference between the detected value of the refrigerant temperature detecting means (236) and the detected value of the evaporating temperature detecting means (234) as the flow state display value, and based on the flow state display value, The state of flow of the supercooling refrigerant in the cooling refrigerant circuit (220) is controlled.

According to a fifteenth invention, in the first, second, or third invention, the utilization unit (12, 13, 14, 14) of the refrigerant passage (205) is replaced with the supercooling heat exchanger (210). The refrigerant temperature detection means (236) for detecting the temperature of the heat source side refrigerant in the nearer part, while the control means (240) determines the flow rate of the heat source side refrigerant by the detection value of the refrigerant temperature detection means (236). In the state where the flow of the cooling fluid in the cooling fluid circuit (220) is stopped, it is determined whether the flow of the cooling fluid is started or stopped. It is configured to be determined based on the state display value.

[0043] In the fifteenth aspect, the detected value of the refrigerant temperature detecting means (236) is input to the control means (240). By monitoring the detected value of the refrigerant temperature detecting means (236), the flow state of the heat source side refrigerant in the refrigerant passage (205) can be determined. For example, if the detected value of the refrigerant temperature detecting means (236) is a certain value or more while the flow of the cooling fluid is stopped. For example, it can be determined that the heat source side refrigerant is circulating in the refrigerant passage (205) toward the use units (12, 13, 14) with the power of the heat source unit (11). Otherwise, the force of the heat application side refrigerant flowing from the utilization unit (12, 13, 14) to the heat source unit (11) in the refrigerant passage (205) or the heat application side refrigerant is It can be determined that it is not flowing. Therefore, the control means (240) uses the detected value of the refrigerant temperature detecting means (236) as the flow state display value, and based on the flow state display value, controls the cooling fluid in the cooling fluid circuit (220). Control the distribution status.

In a sixteenth aspect based on the first, second, or third aspect, the utilization unit (12, 13, 14, 14) of the refrigerant passage (205) is replaced by a subcooling heat exchanger (210). The refrigerant temperature detection means (236) for detecting the temperature of the heat source side refrigerant in the nearer part, while the control means (240) detects a change in the detection value of the refrigerant temperature detection means (236) of the heat source side refrigerant. It is used as a flow state display value indicating the flow state, and in the state where the flow of the cooling fluid in the cooling fluid circuit (220) is stopped, whether to start or continue to stop the flow of the cooling fluid is described above. It is configured to be determined based on the distribution state display value.

[0045] In the sixteenth aspect, the detected value of the refrigerant temperature detecting means (236) is input to the control means (240). By monitoring the change in the detected value of the refrigerant temperature detecting means (236), the flow state of the heat source side refrigerant in the refrigerant passage (205) can be determined. For example, if the detected value of the refrigerant temperature detecting means (236) rises and falls while the flow of the cooling fluid is stopped, the inside of the refrigerant passage (205) is moved from the heat source unit (11) to the utilization unit (11). It can be determined that the heat source side refrigerant is circulating toward 12, 13, 14). Otherwise, the unity (12, 13, 14) force in the refrigerant passage (205) is the force of the heat application side refrigerant flowing toward the heat source unit (11), or the heat application side refrigerant is flowing. You can judge that you have not. Accordingly, the control means (240) uses the change in the detected value of the refrigerant temperature detecting means (236) as a flow state display value, and based on the flow state display value, controls the cooling fluid circuit (220) for cooling. Controls the flow state of the fluid.

In a seventeenth aspect based on the second or third aspect, an outdoor temperature detecting means (231) for detecting a temperature of outdoor air, and a subcooling heat exchanger in the refrigerant passage (205) are provided. A refrigerant temperature detecting means (236) for detecting the temperature of the heat-source-side refrigerant in a portion closer to the utilization unit (12, 13, 14) than the (210). The difference between the detection value of the means (236) and the detection value of the outdoor temperature detection means (231) It is used as a circulation state display value indicating the state, and in a state where the circulation of the supercooling refrigerant in the supercooling refrigerant circuit (220) is stopped, whether to start or continue to stop the circulation of the supercooling refrigerant. Is determined based on the distribution state display value.

[0047] In the seventeenth aspect, the detection values of the outdoor temperature detection means (231) and the refrigerant temperature detection means (236) are input to the control means (240). By comparing the detected value of the refrigerant temperature detecting means (236) with the detected value of the outdoor temperature detecting means (231), it is possible to determine the flow state of the heat source side refrigerant in the refrigerant passage (205). For example, if the difference between the detected value of the refrigerant temperature detecting means (236) and the detected value of the outdoor temperature detecting means (231) is equal to or more than a predetermined value while the circulation of the cooling fluid is stopped, the refrigerant passage (205) It can be determined that the heat source side refrigerant is circulating inside. Otherwise, it can be determined that the enthusiasm-side refrigerant is not flowing in the refrigerant passage (205). Therefore, the control means (240) uses a difference between the detected value of the refrigerant temperature detecting means (236) and the detected value of the outdoor temperature detecting means (231) as a flow state display value, and based on the flow state display value. Controlling the flow state of the supercooling refrigerant in the subcooling refrigerant circuit (220).

[0048] The eighteenth invention provides a refrigeration apparatus (10) that circulates a heat source-side refrigerant between a heat source unit (11) and a use unit (12, 13, 14) connected by a communication pipe to perform a refrigeration cycle. It is intended for a supercooler that is attached and cools the heat source side refrigerant of the refrigeration unit (10) sent to the power utilization unit (12, 13, 14). The heat source unit (11) of the refrigerating device (10) is configured to exchange heat between the heat source side refrigerant and the outdoor air, while the connecting pipe (21, 22) on the liquid side of the refrigerating device (10) is provided. A refrigerant passage (205) connected to the cooling medium, a cooling fluid circuit (220) through which a cooling fluid flows, and a heat source-side refrigerant in the refrigerant passage (205) are cooled by exchanging heat with the cooling fluid. A supercooling heat exchanger (210), an outdoor temperature detecting means (231) for detecting the temperature of outdoor air, and a flow state of the cooling fluid in the cooling fluid circuit (220). Control means (240) for controlling according to the detection value of the temperature detection means (231).

[0049] In the eighteenth aspect, similarly to the first aspect, the heat-source-side refrigerant in the refrigerant passage (205) is cooled by the cooling fluid. The detection value of the outdoor temperature detection means (231) is input to the control means (240) of the present invention. By monitoring the detection value of the outdoor temperature detection means (231) In addition, the magnitude of the cooling load in the utilization unit (12, 13, 14) can be estimated, and it can be determined whether the heat source side refrigerant in the refrigerant passage (205) should be cooled. Therefore, the control means (240) controls the flow state of the cooling fluid in the cooling fluid circuit (220) based on the detection value of the outdoor temperature detecting means (231).

[0050] In a nineteenth aspect based on the eighteenth aspect, the cooling fluid circuit includes a supercooling coolant circuit (220), and the supercooling coolant circuit (220) includes a supercooling coolant circuit (220). It is equipped with a cooling compressor (221) and performs a refrigeration cycle by circulating a supercooling refrigerant as a cooling fluid.

[0051] In the nineteenth aspect, in the subcooling refrigerant circuit (220) of the subcooling device (200), a refrigeration cycle is performed by circulating the subcooling refrigerant. In the subcooling heat exchanger (210), the heat source side refrigerant flowing in the refrigerant passage (205) exchanges heat with the subcooling refrigerant. In the supercooling heat exchanger (210), the supercooling refrigerant absorbs heat from the heat-source-side refrigerant and evaporates, and the heat-source-side refrigerant is cooled.

[0052] In a twentieth aspect based on the eighteenth or nineteenth aspect, the control means (240) is arranged so that the cooling fluid flows in the cooling fluid circuit (220). Whether to continue or stop the flow of the working fluid is determined based on the detection value of the outdoor temperature detecting means (231).

[0053] In a twenty-first aspect based on the eighteenth or nineteenth aspect, the control means (240) is configured to stop the flow of the cooling fluid in the cooling fluid circuit (220). The configuration is such that whether to start or stop the flow of the cooling fluid is determined based on the detection value of the outdoor temperature detecting means (231).

[0054] In the twentieth and twenty-first inventions, the control means (240) monitors the detection value of the outdoor temperature detection means (231). If the detection value of the outdoor temperature detection means (231) exceeds a predetermined reference value (for example, 25 ° C), the cooling load on the utilization unit (12, 13, 14) is increased and the inside of the refrigerant passage (205) is increased. It can be assumed that the heat source side refrigerant is to be cooled. Otherwise, it can be guessed that the cooling load on the IJ IJ units (12, 13, 14) is not so large and the necessity to cool the heat source side refrigerant in the refrigerant passage (205) is low. . Therefore, the control means (240) of these inventions uses the cooling fluid circuit (220) based on the detection value of the outdoor temperature detection means (231). It is determined whether or not the cooling fluid is allowed to flow.

[0055] In a twenty-second aspect based on the second or nineteenth aspect, the radiating heat exchanger (222) is connected to the subcooling refrigerant circuit (220) to exchange heat between the supercooling refrigerant and outdoor air. ), And an outdoor fan (230) for supplying outdoor air to the heat-radiating heat exchanger (222), wherein the supercooling refrigerant circuit (220) is stopped while the supercooling compressor (221) is stopped. By operating the outdoor fan (230) at the same time, a natural circulation operation of naturally circulating the supercooling refrigerant is possible, and the control means (240) performs the operation when starting the circulation of the supercooling refrigerant. Activates the outdoor fan (230) to cause the supercooling refrigerant circuit (220) to perform a natural circulation operation, and makes the heat source side refrigerant flow in the refrigerant passage (205) during the natural circulation operation. And to determine whether to start or continue to stop the subcooling compressor (221) accordingly.

[0056] In the twenty-second aspect, in the subcooling refrigerant circuit (220), the supercooling refrigerant is driven by the outdoor fan (230) even when the subcooling compressor (221) is stopped. Circulate. That is, in the subcooling refrigerant circuit (220), the heat source side refrigerant can be cooled in the subcooling heat exchanger (210) only by operating the outdoor fan (230). When the circulation of the subcooling refrigerant is started, the control means (240) of the present invention first operates only the outdoor fan (230) to naturally circulate the supercooling refrigerant in the subcooling refrigerant circuit (220). Then, the heat source side refrigerant is cooled by the subcooling refrigerant that circulates naturally. Then, the control means (240) determines whether the cooling of the heat source side refrigerant is sufficient in this state, and determines whether or not to activate the supercooling compressor (221) according to the determination. That is, the control means (240) keeps the subcooling compressor (221) stopped if the cooling of the heat source side refrigerant is sufficient, and if the cooling of the heat source side refrigerant is insufficient, the control means (240) (221) is started to start a refrigeration cycle in the subcooling refrigerant circuit (220).

The invention's effect

[0057] In the subcooling device (200) of the present invention, the control means (240) controls the operation of the subcooling compressor (221) according to the state of circulation of the refrigerant inside the refrigerant passage (205). I have. In other words, in the subcooling device (200), even if signals are not exchanged with the refrigeration device (10), the subcooling compressor (221) can be used in accordance with the operation state of the refrigeration device (10). Control the operation of Is possible. Therefore, when attaching the subcooling device (200) of the present invention to the refrigeration system (10), the refrigerant passage of the subcooling device (200) is connected to the liquid-side communication pipes (21, 22) of the refrigeration system (10). (205), and there is no need to lay communication wiring for exchanging signals between the refrigeration system (10) and the subcooling system (200).

[0058] Therefore, according to the present invention, it is possible to reduce the number of man-hours required for attaching the supercooling device (200) to the refrigerating device (10), and to further reduce human error during installation work such as incorrect wiring. The trouble caused by the above can be prevented beforehand.

Brief Description of Drawings

FIG. 1 is a piping diagram showing a configuration of a refrigeration system including a supercooling unit.

FIG. 2 is a piping diagram showing an operation during a cooling operation of the refrigeration system.

FIG. 3 is a piping diagram illustrating an operation of the refrigeration system during a first heating operation.

FIG. 4 is a piping diagram showing an operation of the refrigeration system during a first heating operation.

FIG. 5 is a piping diagram showing an operation during a second heating operation of the refrigeration system.

FIG. 6 is a flowchart showing a control operation of a controller in the supercooling unit.

FIG. 7 is a piping diagram showing a configuration of a refrigeration system according to a first modification of the embodiment.

FIG. 8 is a piping diagram illustrating a configuration of a refrigeration system according to a second modification of the embodiment.

FIG. 9 is a piping diagram illustrating a configuration of a refrigeration system according to Modification Example 5 of the embodiment.

FIG. 10 is a piping diagram showing a configuration of a subcooling unit in Modification 10 of the embodiment.

Explanation of symbols

10 Refrigeration equipment

11 Outdoor unit (heat source unit)

12 Air conditioning unit (Usage unit)

13 Refrigerated showcase (Usage unit)

14 Frozen showcase (Usage unit)

21 1st liquid side connection pipe (liquid side connection pipe)

22 2nd liquid side connection pipe (liquid side connection pipe)

205 refrigerant passage 210 Subcooling heat exchanger

220 Subcooling refrigerant circuit (Cooling fluid circuit)

221 Subcooling compressor

200 Subcooling unit (supercooling device)

230 outdoor fan

234 Suction pressure sensor (evaporation temperature detecting means, evaporating pressure detecting means)

236 Refrigerant temperature sensor (refrigerant temperature detecting means)

237 1st refrigerant temperature sensor (1st refrigerant temperature detecting means)

238 Second refrigerant temperature sensor (second refrigerant temperature detecting means)

240 controller (control means)

251 Flow meter

252 1st subcooling refrigerant temperature sensor (inlet side fluid temperature detection means)

253 Second subcooling refrigerant temperature sensor (outlet fluid temperature detecting means)

BEST MODE FOR CARRYING OUT THE INVENTION

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

[0062] The refrigeration system of the present embodiment is installed in a convenience store or the like, and performs air conditioning in the store and cooling in the showcase. This refrigeration system includes a subcooling unit (200) as a subcooling device according to the present invention, and a refrigeration device (10) to which the subcooling unit (200) is attached.

As shown in FIG. 1, the refrigeration system includes an outdoor unit (11), an air conditioning unit (12), a refrigerated showcase (13), a refrigerated showcase (14), and a booster unit (15). ) And a supercooling unit (200). The outdoor unit (11), the air conditioning unit (12), the refrigerated showcase (13), the refrigerated showcase (14), and the booster unit (15) constitute a refrigeration unit (10). . In this refrigeration system, the outdoor unit (11) and the subcooling unit (200) are installed outdoors, and the remaining air conditioning unit (12) is installed in a store such as a convenience store.

[0064] The outdoor unit (11) has an outdoor circuit (40) power. The air conditioning unit (12) has an air conditioning circuit (100), the refrigeration showcase (13) has a refrigeration circuit (110), and a refrigeration showcase (14). Has a refrigeration circuit ( 130) Power The booster unit (15) is provided with a booster circuit (140). The subcooling unit (200) is provided with a refrigerant passage (205). In the refrigeration system, a refrigerant circuit (20) is configured by connecting these circuits (40, 100,...) And the refrigerant passage (205) of the supercooling unit (200) with piping. This refrigerant circuit (20) is filled with a heat source side refrigerant.

[0065] The refrigerant circuit (20) includes a first liquid side communication pipe (21), a second liquid side communication pipe (22), a first gas side communication pipe (23), and a second gas side communication pipe. A pipe (24) is provided.

[0066] The first liquid side communication pipe (21) connects one end of the refrigerant passage (205) of the subcooling unit (200) to the outdoor circuit (40). One end of the second liquid side communication 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). The branch pipe connected to the refrigeration circuit (130) in the second liquid side connection pipe (22) is provided with a liquid side shutoff valve (25).

[0067] One end of the first gas side communication pipe (23) is branched into two, and a refrigeration circuit (110) and a booster circuit.

(140) and connected. The branch pipe connected to the booster circuit (140) in the first gas-side communication pipe (23) is provided with a gas-side shutoff valve (26). 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).

[0068] <Outdoor unit>

The outdoor unit (11) constitutes a heat source unit of the refrigeration system (10). The outdoor unit (11) includes an outdoor circuit (40).

[0069] The outdoor circuit (40) includes a variable capacity compressor (41), a first fixed capacity compressor (42), a second fixed capacity compressor (43), and an outdoor heat exchanger (44). , A receiver (45), and an outdoor expansion valve (46). The outdoor circuit (40) has three suction pipes (61, 62, 63), two discharge pipes (64, 65), four liquid pipes (81, 82, 83, 84), and 1 In addition, the outdoor circuit (40) includes three four-way switching valves (51, 52, 53), one liquid-side shutoff valve (54), and two high-pressure gas pipes (66). And two gas side shut-off valves (55, 56).

[0070] In the outdoor circuit (40), the first liquid side connecting pipe (21) force S is connected to the liquid side closing valve (54), and the first gas side connecting pipe (55) is connected to the first gas side closing valve (55). 23) Force The second gas side shut-off valve (56) The gas side communication pipes (24) are respectively connected.

[0071] The variable displacement compressor (41), the first fixed displacement compressor (42), and the second fixed displacement compressor (43) are all hermetic, 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 output frequency of the inverter and changing the rotation speed of the compressor motor. On the other hand, in the first and second fixed displacement compressors (42, 43), the compressor motor is always operated at a constant rotation speed, and the displacement thereof cannot be changed.

[0072] One end of the first suction pipe (61) is connected to the first gas-side stop valve (55). The first suction pipe (61) is branched at the other end into a first branch pipe (61a) and a second branch pipe (61b), and the first branch pipe (61a) is connected to the variable displacement compressor (41). ), The second branch pipe (61b) is connected to the third four-way switching valve (53), respectively. In the second branch pipe (61b) of the first suction pipe (61), only the refrigerant flowing from the first gas side shut-off valve (55) to the third four-way switching valve (53) is allowed to flow. A valve (CV-1) is provided.

[0073] 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 displacement compressor (42).

[0074] 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 connected to 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) allows only the flow of the refrigerant flowing from the second four-way switching valve (52) to the third four-way switching valve (53). A valve (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 displacement compressor (64). The second branch pipe (64b) is connected to the discharge side of the first fixed displacement compressor (42) on the discharge side of 41). The other end of the first discharge pipe (64) is connected to the first four-way switching valve (51). The second branch pipe (64b) of the first discharge pipe (64) has a check valve (64) that allows only the flow of the refrigerant from the first fixed displacement compressor (42) to the first four-way switching valve (51). CV-3) is provided. [0076] The second discharge pipe (65) has one end on the suction side of the second fixed displacement compressor (43) and the other end on the first four-way switching valve (51) in the first discharge pipe (64). Each is connected immediately before. The second discharge pipe (65) is provided with a check valve (CV-4) that allows only refrigerant to flow from the second fixed displacement compressor (43) to the first four-way switching valve (51). ing.

[0077] 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 a first four-way switching valve (51) via a 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 flow of the refrigerant from the outdoor heat exchanger (44) to the receiver (45).

[0078] 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 stop valve (54). The second liquid pipe (82) is provided with a check valve (CV-6) that allows only the flow of the refrigerant from the receiver (45) to the liquid-side stop valve (54).

One end of the third liquid pipe (83) is connected between the check valve (CV-6) and the liquid side stop 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). Further, the third liquid pipe (83) is provided with a check valve (CV-7) that allows only the flow of the refrigerant from one end to the other end.

[0080] One end of the fourth liquid pipe (84) is connected between the close 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). Further, the fourth liquid pipe (84) is provided with a check valve (CV-8) and an outdoor expansion valve (46) in order from one end to the other end. The check valve (CV-8) allows only one direction of the fourth liquid pipe (84) to flow to the other end of the fourth liquid pipe (84). The outdoor expansion valve (46) is formed by an electronic expansion valve.

[0081] One end of the high-pressure gas pipe (66) is connected to the first discharge pipe (64) immediately before the first four-way switching valve (51). The high-pressure gas pipe (66) is branched at the other end into a first branch pipe (66a) and a second branch pipe (66b), 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 switching valve (53) downstream of the check valve (CV-5). High The first branch pipe (66a) of the compressed gas pipe (66) is provided with a solenoid valve (SV-7), a check valve (CV-9) and a force S. The check valve (CV-9) is arranged downstream of the solenoid valve (SV-7), and allows only the flow of the refrigerant from the solenoid valve (SV-7) to the first liquid pipe (81).

[0082] 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. Is connected to the outdoor heat exchanger (44), and the fourth port is connected to the second gas side shut-off valve (56). The first four-way switching valve (51) is in a first state 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 (in FIG. 1, a solid line indicates a solid state). State), and a second state (a state shown 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. Has become.

[0083] In the second four-way switching valve (52), the first port is located downstream of the check valve (CV-4) in the second discharge pipe (65), and the second port is located in the second suction pipe ( At the beginning of 62), the fourth port is connected to the second port of the first four-way switching valve (51). The third port of the second four-way switching valve (52) is sealed. The second four-way switching valve (52) is in a first state where the first port and the third port are in communication with each other and the second and fourth ports are in communication with each other (in FIG. State), and a second state (a state shown 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. I have.

[0084] The third four-way switching 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 end of the second suction pipe (62). At the beginning, the third port is at the end of the second branch pipe (61b) of the first suction pipe (61), and the fourth port is at the end of the second branch pipe (63b) of the third suction pipe (63). Each is connected. The third four-way switching valve (53) is in a first state in which the first port and the third port are in communication with each other and the second and fourth ports are in communication with each other (the state shown by the solid line in FIG. 1). ) And a second state 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 state shown by the broken line in FIG. 1).

[0085] 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). [0086] 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). It is connected. The injection pipe (85) is provided with a closing valve (59) and a flow control valve (86) in order from one end to the other end. The flow control valve (86) is formed by an electronic expansion valve.

[0087] The communication pipe (87) has one end between the closing valve (59) and the flow control valve (86) in the injection pipe (85), and the other end having the first branch pipe (66) of the high-pressure gas pipe (66). They are connected upstream of the solenoid valve (SV-7) in 66a). The communication pipe (87) is provided with a check valve (CV-10) that allows only the flow of the directional refrigerant from one end to the other end.

[0088] 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 refrigeration oil from the gas discharged from the compressors (41, 42).

[0089] The oil return pipe (76) has one end connected to the oil separator (75). The oil return pipe (76) is branched at the other end into a first branch pipe (76a) and a second branch pipe (76b). The first branch pipe (76a) has a flow rate in the S injection pipe (85). Downstream of the control valve (86), second branch pipes (76b) are connected to the second suction pipes (62), respectively. Also, 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 refrigerating machine 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 refrigerating machine oil separated by the oil separator (75) is sent back to the second suction pipe (62).

[0090] The first oil equalizing pipe (71) has one end connected to the variable displacement compressor (41) and the other end connected to the second suction pipe (62). The first oil level pipe (71) is provided with a solenoid valve (SV-1). One end of the second oil equalizing pipe (72) is connected to the first fixed displacement compressor (42), and the other end is connected to the first branch pipe (63a) of the third suction pipe (63). The second oil leveling pipe (72) is provided with a solenoid valve (SV-2). One end of the third oil equalizing pipe (73) is connected to the second fixed capacity compressor (43), and the other end is connected to the first branch pipe (61a) of the first suction pipe (61). The third oil level pipe (73) is provided with a solenoid valve (SV-3). The fourth equalizing pipe (74) has one end Is connected to the second oil equalizing pipe (72) on the upstream side of the solenoid valve (SV-2), and the other end is connected to the first branch pipe (61a) of the first suction pipe (61). The fourth oil leveling 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.

[0091] The outdoor circuit (40) is also provided with various sensors and pressure switches. Specifically,

The first suction pipe (61) is provided with a first suction temperature sensor (91) and a first suction pressure sensor (92). The second suction pipe (62) is provided with a second suction pressure sensor (93). The third suction pipe (63) is provided with a third suction temperature sensor (94) and a third suction pressure sensor (95). The first discharge pipe (64) is provided with a first discharge temperature sensor (97) and a first discharge pressure sensor (98). Each branch pipe (64a, 64b) of the first discharge pipe (64) is provided with one high pressure switch (96). The second discharge pipe (65) is provided with a second discharge temperature sensor (99) and a high pressure switch (96).

[0092] The outdoor unit (11) is provided with an outdoor temperature sensor (90) and an outdoor fan (48). Outdoor air is sent to the outdoor heat exchanger (44) by the outdoor fan (48).

[0093] <Air conditioning unit>

The air conditioning unit (12) forms a use unit. The air conditioning unit (12) includes an air conditioning circuit (100). The air-conditioning circuit (100) has a liquid-side end connected to a second liquid-side connecting pipe (22) and a gas-side end connected to a second gas-side connecting pipe (24).

[0094] In the air conditioning circuit (100), an air conditioning expansion valve (102) and an air conditioning heat exchanger (101) are provided in that order toward the liquid end force gas end. The air conditioning heat exchanger (101) is a cross-fin type fin-and-tube heat exchanger. In this air-conditioning heat exchanger (101), heat is exchanged between the refrigerant and room air. On the other hand, the air conditioning expansion valve (102) is constituted by an electronic expansion valve.

[0095] The air conditioning unit (12) is provided with a heat exchanger temperature sensor (103) and a refrigerant temperature sensor (104). The heat exchanger temperature sensor (103) is attached to a heat transfer tube of the air conditioning heat exchanger (101). The refrigerant temperature sensor (104) is mounted near the gas side end of the air conditioning circuit (100). The air conditioning unit (12) is provided with an internal temperature sensor (106) and an air conditioning fan (105). The air conditioning heat exchanger (101) is supplied to the store by this air conditioning fan (105). The indoor air inside is sent.

[0096] <Refrigerated showcase>

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

[0097] The refrigeration circuit (110) is provided with a refrigeration solenoid valve (114), a refrigeration expansion valve (112), and a refrigeration heat exchanger (111) in order from the liquid side end to the gas side end. . The refrigeration heat exchanger (111) is a cross-fin type fin-and-tube heat exchanger. In the refrigeration heat exchanger (111), heat is exchanged between the refrigerant and the air in the refrigerator. The refrigeration expansion valve (112) is constituted by a temperature automatic expansion valve. The temperature sensing cylinder (113) of the refrigeration expansion valve (112) is attached to the outlet pipe of the refrigeration heat exchanger (111).

[0098] The refrigerated showcase (13) is provided with a refrigerator temperature sensor (116) and a refrigerator fan (115). The air in the refrigerator showcase (13) is sent to the refrigerator heat exchanger (111) by the fan (115) in the refrigerator.

[0099] <Frozen showcase>

The frozen showcase (14) constitutes a use unit. 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.

[0100] In the refrigeration circuit (130), a refrigeration solenoid valve (134), a refrigeration expansion valve (132), and a refrigeration heat exchanger (131) are provided in order from the liquid side end to the gas side end. . 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 air in the refrigerator. The refrigeration expansion valve (132) is constituted by a temperature automatic expansion valve. The temperature sensing tube (133) of the refrigeration expansion valve (132) is attached to a pipe on the outlet side of the refrigeration heat exchanger (131).

[0101] The freezer showcase (14) is provided with a freezer temperature sensor (136) and a freezer fan (135). The air inside the refrigerator showcase (14) is sent to the refrigerator heat exchanger (131) by the refrigerator fan (135). [0102] <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).

[0103] The booster compressor (141) is a hermetically sealed high-pressure dome-type scroll compressor. Power is supplied to the booster compressor (141) via an inverter. The capacity of the booster compressor (141) can be changed by changing the output frequency of the inverter to change the rotation speed of the compressor motor.

[0104] The end of the suction pipe (143) is connected to the suction side of the booster compressor (141). The start end of the suction pipe (143) is connected to the gas side end of the refrigeration circuit (130) via a pipe.

[0105] The discharge pipe (144) has a start end connected to the discharge side of the booster compressor (141) and an end end connected to the first gas side communication pipe (23). The discharge pipe (144) is provided with a high pressure switch (148), an oil separator (145), and a discharge check valve (149) in order from the start end to the end end. . The discharge side check valve (149) allows only the flow of the refrigerant from the start end to the end of the discharge pipe (144).

[0106] The oil separator (145) is for separating refrigeration 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).

[0107] The bypass pipe (150) has a start end connected to the suction pipe (143), and an end connected between the oil separator (145) and the discharge-side check valve (149) in the discharge pipe (64). I have. The bypass pipe (150) is provided with a bypass check valve (151) that allows only the flow of the directional refrigerant from the start end to the end.

[0108] <Supercooling unit>

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

[0109] The refrigerant passage (205) has one end connected to the first liquid side connection pipe (21) and the other end connected to the second liquid side connection pipe. Each is connected to a pipe (22).

[0110] The subcooling refrigerant circuit (220) includes a subcooling compressor (221), a subcooling outdoor heat exchanger (2 22), a subcooling expansion valve (223), and a subcooling heat source. This is a closed circuit configured by connecting the exchanger (210) in sequence with piping. The supercooling refrigerant circuit (220) forms a cooling fluid circuit. The supercooling refrigerant circuit (220) is filled with a supercooling refrigerant as a cooling fluid. As the supercooling refrigerant, not only so-called chlorofluorocarbon refrigerant such as R407C but also various refrigerants such as carbon dioxide (CO 2) and ammonia can be used. This supercooling

2

In the refrigerant circuit (220), a refrigeration cycle is performed by circulating the filled subcooling refrigerant.

[0111] The supercooling compressor (221) is an all-enclosed high-pressure dome-type scroll compressor. Power is supplied to the subcooling compressor (221) via an inverter. The capacity of the subcooling compressor (221) can be changed by changing the output frequency of the inverter to change the rotation speed of the compressor motor. The supercooling outdoor heat exchanger (222) is a cross-fin type fin 'and' tube type heat exchanger. In the subcooling outdoor heat exchanger (222), heat is exchanged between the subcooling refrigerant and the outdoor air. The subcooling expansion valve (223) is constituted by an electronic expansion valve.

[0112] The subcooling heat exchanger (210) is constituted by a so-called plate heat exchanger. The supercooling heat exchanger (210) has a plurality of first flow paths (211) and a plurality of second flow paths (212). A supercooling refrigerant circuit (220) is connected to the first flow path (211), and a refrigerant passage (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 refrigerating device (10) flowing through the second flow path (212). Let it.

[0113] The subcooling unit (200) is also provided with various sensors and pressure switches. Specifically, in the subcooling refrigerant circuit (220), a suction temperature sensor (235) and a suction pressure sensor (234) are provided on the suction side of the subcooling compressor (221), and the subcooling compressor (221) is provided. A discharge temperature sensor (233) and a high pressure switch (232) are provided on the discharge side of (221). In the refrigerant passage (205), a refrigerant temperature sensor (236) is provided at 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 communication pipe (22). Is provided. This refrigerant temperature The sensor (236) constitutes a refrigerant temperature detecting means.

[0114] The subcooling unit (200) is provided with an outside air temperature sensor (231) and an outdoor fan (230). Outdoor air is sent to the subcooling outdoor heat exchanger (222) by the outdoor fan (230).

[0115] The controller (240) forms control means. The controller (240) receives the detection value of the refrigerant temperature sensor (236), the detection value of the suction pressure sensor (234), and the detection value of the outside air temperature sensor (231). The controller (240) is configured to control the start and stop of the subcooling compressor (221) based on the input detection value of the sensor. The controller (240) does not receive any power signal from the refrigeration system (10) composed of the outdoor unit (11) and the air conditioning unit (12). In other words, the controller (240) uses only the information obtained inside the subcooling unit (200), such as the detection value of the sensor provided in the subcooling unit (200), and The operation control of 221) is performed.

[0116] Operation of refrigeration system

The main operation operations performed by the refrigeration system will be described.

[0117] <Cooling operation>

The cooling operation is an operation for cooling the inside of the store by cooling the air in the refrigerator in the refrigerated showcase (13) and the freezing showcase (14), and cooling the room air in the air conditioning unit (12).

[0118] As shown in FIG. 2, during the cooling operation, the first four-way switching valve (51), the second four-way switching valve (52), and the third four-way switching valve (53) are each connected to the first four-way switching valve (53). Set to state. In addition, 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 appropriately adjusted. 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 this cooling operation, the subcooling unit (200) is in an operating state. The operation of the subcooling unit (200) will be described later.

[0119] Variable displacement compressor (41), first fixed displacement compressor (42), and second fixed displacement compressor (43) Force The discharged refrigerant passes through the first four-way switching valve (51). To the outdoor heat exchanger (44). In the outdoor heat exchanger (44), the refrigerant radiates heat to outdoor air and condenses. Outdoor heat exchanger ( The refrigerant condensed in 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 communication pipe (21).

[0120] The refrigerant flowing into the first liquid side communication pipe (21) flows into the refrigerant passage (205) of the subcooling unit (200). The refrigerant flowing into the refrigerant passage (205) is cooled while passing through the second flow passage (212) of the subcooling heat exchanger (210). The supercooled liquid refrigerant cooled by the supercooling heat exchanger (210) passes through the second liquid-side communication pipe (22), and passes through the air conditioning circuit (100), the refrigeration circuit (110), and the refrigeration circuit (130). And distributed to.

[0121] The refrigerant flowing into the air conditioning circuit (100) is decompressed when passing through the air conditioning expansion valve (102), and is then introduced into the air conditioning heat exchanger (101). In the air-conditioning heat exchanger (101), the refrigerant absorbs indoor air power and evaporates. At that time, in the air-conditioning heat exchanger (101), the evaporation temperature of the refrigerant is set to, for example, about 5 ° C. In the air conditioning unit (12), room air cooled by the air conditioning heat exchanger (101) is supplied into the store.

[0122] 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 flows to the first four-way switching valve (51). It passes through the second four-way 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 remaining refrigerant flows into the second branch pipe (63b). The gas passes through the third four-way switching valve (53) and the second suction pipe (62) in order and is sucked into the first fixed displacement compressor (42).

[0123] The refrigerant that has flowed into the refrigeration circuit (110) is decompressed when passing through the refrigeration expansion valve (112), and is introduced into the power refrigeration heat exchanger (111). In the refrigeration heat exchanger (111), the refrigerant evaporates by absorbing heat inside the refrigerator. 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 air in the refrigerator cooled by the refrigeration heat exchanger (111) is supplied into the refrigerator, and the temperature in the refrigerator is maintained at, for example, about 5 ° C.

[0124] The refrigerant flowing into the refrigeration circuit (130) is decompressed when passing through the refrigeration expansion valve (132), and is introduced into the power refrigeration heat exchanger (131). In the refrigeration heat exchanger (131), the refrigerant evaporates by absorbing heat inside the refrigerator. 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 refrigeration heat exchanger (131) The rejected air in the refrigerator is supplied to the refrigerator, and the temperature in the refrigerator is kept at, for example, about 20 ° C.

[0125] 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).

[0126] 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. Then, these refrigerants pass through the first gas side communication pipe (23) and flow into the first suction pipe (61) of the outdoor circuit (40). 1st suction pipe (

The refrigerant flowing into 61) is sucked into the variable displacement compressor (41) through the first branch pipe (61a).

[0127] <First heating operation>

The first heating operation is an operation in which the inside of the refrigerator is cooled in the refrigerated showcase (13) and the frozen showcase (14), and the room air is heated by the air conditioning unit (12) to heat the inside of the store.

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 (52) is in the third state. The path switching valves (53) are set to the first state, respectively. Further, while the outdoor expansion valve (46) is fully closed, the opening degree of the air-conditioning expansion valve (102), the refrigeration expansion valve (112), and the refrigeration expansion valve (132) is appropriately adjusted. 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. In addition, the outdoor heat exchanger (44) is in a stopped state without being supplied with the refrigerant. During this first heating operation, the subcooling unit (200) is in a stopped state.

[0129] The refrigerant discharged from the variable displacement compressor (41) passes through the first four-way switching valve (51) and the second gas side communication pipe (24) in order, and exchanges air conditioning heat in the air conditioning circuit (100). It is introduced into the vessel (101) and releases heat to indoor air to condense. In the air conditioning unit (12), the 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).

[0130] In the refrigerated showcase (13) and the frozen showcase (14), the air in the refrigerator is cooled as in the cooling operation. The refrigerant that has flowed 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, flow to the refrigeration circuit (130) The entered refrigerant evaporates in the refrigerating heat exchanger (131), is 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) is sucked into the variable capacity compressor (41) after passing through the first suction pipe (61) and is compressed.

[0131] As described above, in the first heating operation, the refrigerant absorbs heat in the refrigeration heat exchanger (111) and the refrigeration heat exchanger (131), and dissipates heat in the air conditioning heat exchanger (101). Then, the interior of the store is heated by utilizing the heat of the refrigerant that has absorbed heat from the air in the refrigerator in the refrigeration heat exchanger (111) and the freezing heat exchanger (131).

[0132] During the first heating operation, as shown in Fig. 4, the first fixed displacement 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). In this case, the third four-way switching valve (53) is set to the second state. Then, a part of the refrigerant flowing into the first suction pipe (61) passes through the first branch pipe (61a) and is sucked into the variable displacement compressor (41), and the rest flows into the second branch pipe (61b). The air is sucked into the first fixed displacement compressor (42) through the third four-way switching valve (53) and the second suction pipe (62) in order.

[0133] <Second heating operation>

The second heating operation is an operation for heating the inside of the store similarly to the first heating operation. The second heating operation is performed when the heating capacity is insufficient in the first heating operation.

As shown in FIG. 5, 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 (52) is in the third state. The path switching valves (53) are set to the first state, respectively. Further, the opening degrees of the outdoor expansion valve (46), the air conditioning expansion valve (102), the refrigeration expansion valve (112), and the refrigeration expansion valve (132) are appropriately adjusted. In this state, the variable capacity compressor (41), the second fixed capacity compressor (43), and the booster compressor (141) are operated, and the first fixed capacity compressor (42) is stopped. During this first heating operation, the subcooling unit (200) is in a stopped state.

[0135] The refrigerant discharged from the variable capacity compressor (41) and the second fixed capacity compressor (43) passes through the first four-way switching valve and the second gas side communication pipe (24) in order, and is supplied to the air conditioning circuit. It is introduced into the air conditioning heat exchanger (101) of (100), and releases heat to indoor air to condense. In the air conditioning unit (12), the room air heated by the air conditioning heat exchanger (101) is supplied into the store. Condensed in the air conditioning heat exchanger (101) The cooled refrigerant flows into the second liquid side communication pipe (22). A part of the refrigerant flowing into the second liquid side communication pipe (22) is distributed to the refrigeration circuit (110) and the refrigeration circuit (130), and the remainder is the refrigerant passage (205) of the supercooling unit (200). Is introduced to

[0136] In the refrigerated showcase (13) and the frozen showcase (14), the air in the refrigerator is cooled as in the cooling operation. The refrigerant that has flowed 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 flowing into the refrigeration circuit (130) evaporates in the refrigeration heat exchanger (131), is compressed in the booster compressor (141), and then flows into the first gas side communication pipe (23). . Then, the refrigerant flowing into the first gas side communication pipe (23) is sucked into the variable capacity compressor (41) after passing through the first suction pipe (61), and is compressed.

[0137] The refrigerant flowing into the refrigerant passage (205) of the subcooling unit (200) passes through the first liquid side connection pipe (21) and the third liquid pipe (83) in order and flows into the receiver (45). Then, it flows into the fourth liquid pipe (84) through the second liquid pipe (82). The refrigerant that has flowed into the fourth liquid pipe (84) is decompressed when passing through the outdoor expansion valve (46), is introduced into the outdoor heat exchanger (44), absorbs heat from outdoor air, and evaporates. The refrigerant evaporated in the outdoor heat exchanger (44) passes through the first four-way switching valve (51) and the second four-way switching valve (52) in order and flows into the second suction pipe (62). 2Suctioned into the fixed capacity compressor (43) and compressed.

[0138] As described above, in the second heating operation, the refrigerant absorbs heat in the refrigeration heat exchanger (111), the refrigerating heat exchanger (131), and the outdoor heat exchanger (44), and the air conditioning heat exchanger (101 ), The refrigerant radiates heat. Then, using the heat of the refrigerant absorbing heat from the indoor air in the refrigeration heat exchanger (111) and the freezing heat exchanger (131), and the heat of the refrigerant absorbing heat from the outdoor air in the outdoor heat exchanger (44). The inside of the store is heated.

[0139] Operation of the subcooling unit 1

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

As shown in FIG. 1, the supercooling refrigerant discharged from the supercooling compressor (221) radiates heat to outdoor air in the supercooling outdoor heat exchanger (222) to condense. Subcooling outdoor heat exchanger (2 The subcooling refrigerant condensed in 22) is decompressed when passing through the subcooling expansion valve (223), and flows into the first flow path (211) of the power subcooling heat exchanger (210). In the first flow path (211) of the subcooling heat exchanger (210), the supercooling refrigerant evaporates by absorbing the heat of the refrigerant in the second flow path (212). The subcooling refrigerant evaporated in the subcooling heat exchanger (210) is drawn into the subcooling compressor (221) and compressed.

[0141] As described above, the controller (240) controls the start and stop of the subcooling compressor (221) based on the input detection value of the sensor. Here, the control operation of the controller (240) will be described with reference to FIG. The control operation of the controller (240) is repeatedly performed at fixed time intervals (for example, at 10 second intervals).

[0142] First, in step ST10, it is determined whether the subcooling compressor (221) is operating or stopped.

[0143] If it is determined in step ST10 that the supercooling compressor (221) is operating, the process proceeds to step ST11. In step ST11, it is determined whether or not a predetermined time (for example, 2 minutes) has elapsed since the supercooling compressor (221) was started. Then, if the predetermined time has elapsed from the start of the supercooling compressor (221), the process proceeds to step ST12. On the other hand, if the predetermined time has not elapsed, the process proceeds to step ST14 to end the control operation and to continue the operation of the supercooling compressor (221).

In step ST12, it is determined whether to stop the subcooling compressor (221). In this step ST12, it is determined whether or not the following four conditions are satisfied. If any one of these four conditions is satisfied, the process moves to step ST13 and stops the subcooling compressor (221). On the other hand, if all of these four conditions are not satisfied, the process proceeds to step ST14, where the control operation is temporarily ended, and the operation of the supercooling compressor (221) is continued.

[0145] The first condition in step ST12 will be described. The first condition is a condition for determining whether or not the detected value of the refrigerant temperature sensor (236) decreases smoothly after the activation of the subcooling compressor (221).

[0146] In order to satisfy the first condition of Step ST12, the following six requirements must be satisfied. The first requirement is that the detection value Ta of the outside air temperature sensor (231) is less than 20 ° C (Ta <20). Things. The second requirement is that the detected value Tout # 0 of the refrigerant temperature sensor (236) at the start of the subcooling compressor (221) and the refrigerant temperature one minute after the start of the subcooling compressor (221) The difference from the detection value Tout # l of the sensor (236) is 3 ° C or less (Tout # 0-Tout # l≤3). The third requirement is that the detection value ToutttO of the refrigerant temperature sensor (236) at the time of starting the subcooling compressor (221) and the refrigerant temperature sensor (236) after two minutes from the start of the supercooling compressor (221). ) Is less than 5 ° C (Tout # 0_Tout # 2≤5). The fourth requirement is that the detected value ToutttO of the refrigerant temperature sensor (236) at the time of starting the subcooling compressor (221) and the refrigerant temperature sensor (236) after 3 minutes from the start of the subcooling compressor (221). ) Is 7 ° C or less (Tout # 0_Tout # 3≤7). The fifth requirement is that the starting point power of the subcooling compressor (221) has already passed for 3 minutes. The sixth requirement is that the refrigerant temperature sensor (236) operates normally.

[0147] When all of the first to sixth requirements are satisfied, the temperature of the outdoor air is not so high and the cooling capacity of the supercooling heat exchanger (210) is sufficiently obtained. Regardless, the detected value Tout of the refrigerant temperature sensor (236) does not decrease so much. For this reason, when the first condition of step ST12 is satisfied, the refrigerant is not flowing through the refrigerant passage (205) as in the first heating operation, or is not in the second heating operation. It can be determined that the refrigerant flows in the refrigerant passage (205) toward the outdoor unit (11). Therefore, when the first condition is satisfied, the controller (240) causes the refrigeration system (10) to operate the subcooling unit (20).

It is determined that the operation state does not require the operation of 0), and the supercooling compressor (221) is stopped.

[0148] The second condition in step ST12 will be described. The second condition is that the subcooling compressor (22

This is a condition for determining whether or not the detected value of the refrigerant temperature sensor (236) during the operation of 1) is an appropriate value corresponding to the evaporation temperature of the subcooling refrigerant.

[0149] In order to satisfy the second condition of Step ST12, the following four requirements must be satisfied. The first requirement is that 5 minutes have already passed since the start of the supercooling compressor (221). The second requirement is that the detection value Tout of the refrigerant temperature sensor (236) is larger than the value obtained by adding 15 to the evaporation temperature Tg of the supercooling refrigerant in the supercooling heat exchanger (210) (Tout> Tg + 15). The third requirement is that the refrigerant temperature sensor (236) operates normally. The fourth requirement is that the suction pressure sensor (234) is operating normally.

[0150] In this controller (240), the saturation temperature of the subcooling refrigerant at the detection value LP of the suction pressure sensor (234) is regarded as the evaporation temperature Tg of the subcooling refrigerant. That is, in this embodiment, the evaporating temperature detecting means for detecting the evaporating temperature of the subcooling refrigerant is constituted by the suction pressure sensor (234).

[0151] When all of the first to fourth requirements are satisfied, the detection value of the refrigerant temperature sensor (236) is obtained despite the fact that the refrigeration cycle is being performed in the subcooling refrigerant circuit (220). The difference between Tout and the evaporation temperature Tg of the supercooling refrigerant is larger than 15 ° C. For this reason, even when the second condition of step ST12 is satisfied, the state of the refrigerant not flowing in the refrigerant passage (205) as in the first heating operation, and the refrigerant as in the second heating operation. It can be determined that the refrigerant flows in the passage (205) toward the outdoor unit (11). Therefore, when the second condition is satisfied, the controller (240) determines that the refrigeration system (10) is in an operating state that does not require the operation of the subcooling unit (200), and the controller (221) ) To stop.

[0152] The third condition in Step ST12 will be described. The third condition is satisfied when the detected value LP of the suction pressure sensor (234) is less than 0.2 MPa and the suction pressure sensor (234) is abnormal. In this case, since the detection value of the suction pressure sensor (234) is not normal, the operation of the supercooling compressor (221) cannot be appropriately controlled based on the detected value. Therefore, when the third condition is satisfied, the controller (240) stops the subcooling compressor (221).

[0153] The fourth condition in step ST12 will be described. The fourth condition is satisfied when the detection value LP of the suction pressure sensor (234) is less than 0.15 MPa. In this case, the detection value of the suction pressure sensor (234) is a value that is possible in a normal operation state, that is, a value that is as low as possible. Therefore, when the fourth condition is satisfied, the controller (240) determines that some trouble has occurred and stops the supercooling compressor (221).

[0154] If it is determined in step ST10 that the subcooling compressor (221) is stopped, the process proceeds to step ST15. In step ST15, a predetermined time has elapsed since the supercooling compressor (221) was stopped. It is determined whether or not it has passed. When the subcooling compressor (221) is stopped and stopped for a certain period of time to prevent the start and stop of the subcooling compressor (221) from being repeated in a short time. The restart of the subcooling compressor (221) is restricted until the time elapses. In step ST15, if the predetermined time has not elapsed since the stop of the supercooling compressor (221), the process proceeds to step ST14, where the control operation is temporarily ended, and the supercooling compressor (221) is held in the stopped state. I do. On the other hand, if the predetermined time has elapsed since the supercooling compressor (221) was stopped, the process proceeds to Step ST16.

In step ST16, it is determined whether to start the subcooling compressor (221).

In this step ST16, it is determined whether or not the following three conditions are satisfied. If any one of these three conditions is satisfied, the process moves to step ST17 to start the subcooling compressor (221). On the other hand, if all of these three conditions are not satisfied, the process proceeds to step ST14, where the control operation is temporarily ended, and the subcooling compressor (221) is kept stopped.

[0156] The first condition in step ST16 will be described. The first condition is satisfied when the detected value Ta of the outside air temperature sensor (231) is equal to or higher than 25 ° C and one minute has already elapsed since the supercooling compressor (221) was stopped. is there. In this case, the supercooling compressor (221) has been stopped for more than one minute, even though the outdoor air is quite hot. Therefore, when the first condition is satisfied, the controller (240) starts the supercooling compressor (221) to cool the refrigerant in the refrigerant passage (205).

[0157] The second condition in step ST16 will be described. The second condition is satisfied when the detection value Ta of the outside air temperature sensor (231) is equal to or higher than 20 ° C and three minutes have already elapsed since the stop of the supercooling compressor (221). is there. In this case, the supercooling compressor (221) has been in a stopped state for more than three minutes, even though the outdoor air is relatively hot. Then, when the second condition is satisfied, the controller (240) starts the supercooling compressor (221) to cool the refrigerant in the refrigerant passage (205).

[0158] The third condition in step ST16 will be described. The third condition is satisfied when 10 minutes have already passed since the stop of the subcooling compressor (221). In this case, the supercooling compressor (221) has been stopped for a relatively long time. Therefore When the third condition is satisfied, the controller (240) activates the supercooling compressor (221) to cool the refrigerant in the refrigerant passage (205). As described above, the controller (240) always starts the subcooling compressor (221) when the stop time of the subcooling compressor (221) reaches 10 minutes or more.

[0159] Effect of one embodiment-

In the subcooling unit (200), the controller (240) controls the supercooling based only on information obtained in the subcooling unit (200), such as a detection value of a sensor provided in the subcooling unit (200). Controls the operation of the cooling compressor (221). In other words, in this subcooling unit (200), the supercooling compressor (221) can be operated in accordance with the operating state of the refrigeration system (10) without transmitting or receiving signals to or from the refrigeration system (10). Operation can be controlled. Therefore, when attaching the subcooling unit (200) to the refrigeration system (10), the supercooling unit (200) is connected to the first and second liquid side communication pipes (21, 22) of the refrigeration system (10). Just connecting the refrigerant passage (205) eliminates the need to lay communication wiring for transmitting and receiving signals between the refrigeration system (10) and the subcooling unit (200).

[0160] Therefore, according to the present embodiment, it is possible to reduce the number of man-hours for attaching the supercooling unit (200) to the refrigeration system (10), and further to reduce human error during installation work such as incorrect wiring. The trouble caused by the above can be prevented beforehand.

[0161] Here, in order to exchange signals between the subcooling unit (200) and the refrigerating device (10), a communication interface is required not only for the subcooling unit (200) but also for the refrigerating device (10). Become. For this reason, for the supercooling unit (200) that requires a signal input from the refrigeration unit (10) for operation control, applicable refrigeration unit (10) models are limited, and the subcooling unit (200) is limited. There was also a problem that usability was not good.

[0162] On the other hand, the supercooling unit (200) of the present embodiment does not require any signal exchange with the refrigeration apparatus (10), and is restricted by the refrigeration apparatus (10) to be attached. I can't. Therefore, according to the present embodiment, it is possible to eliminate restrictions on the model of the cooling device (10) to which the supercooling unit (200) is attached, and to greatly improve the usability of the supercooling unit (200). be able to.

[0163] Modification of one embodiment 11 In the subcooling unit (200) of the present embodiment, temperature sensors (237,238) are provided on both sides of the subcooling heat exchanger (210) in the refrigerant passage (205), and the detected values of these temperature sensors (237,238) are The operation of the subcooling compressor (221) may be controlled on the basis of the operation.

As shown in FIG. 7, in the refrigerant passage (205), a portion closer to the other end than the supercooling heat exchanger (210), ie, closer to the end connected to the second liquid side communication pipe (22). Is provided with a first refrigerant temperature sensor (237). In the refrigerant passage (205), a second refrigerant temperature sensor is provided at a portion closer to one end than the supercooling heat exchanger (210), that is, a portion closer to the end connected to the first liquid side communication pipe (21). (238) is provided. In this subcooling unit (200), the first refrigerant temperature sensor (237) constitutes first refrigerant temperature detection means, and the second refrigerant temperature sensor (238) constitutes second refrigerant temperature detection means.

[0165] The detection value of the first refrigerant temperature sensor (237) and the detection value of the second refrigerant temperature sensor (238) are input to the controller (240) of the present modification. The controller (240) compares the values detected by the two refrigerant temperature sensors (237, 238) during operation of the subcooling compressor (221), and controls the operation of the subcooling compressor (221) according to the result. It is configured to determine whether to continue or stop.

[0166] The control operation of the controller (240) will be described.

First, if the detected value of the first refrigerant temperature sensor (237) is lower than the detected value of the second refrigerant temperature sensor (238) during the operation of the subcooling compressor (221), The temperature of the refrigerant cooled by the heat exchanger (210) is detected by the first refrigerant temperature sensor (237). Therefore, in this case, the refrigerant flows in the refrigerant passage (205) from the first liquid side communication pipe (21) to the second liquid side communication pipe (22), for example, during a cooling operation. The controller (240) continues the operation of the subcooling compressor (221).

[0168] On the other hand, if the detected value of the second refrigerant temperature sensor (238) is lower than the detected value of the first refrigerant temperature sensor (237) during the operation of the subcooling compressor (221), the subcooling is performed. The temperature of the refrigerant cooled by the heat exchanger (210) is detected by the second refrigerant temperature sensor (238). Accordingly, in this case, for example, the refrigerant flows from the second liquid side communication pipe (22) side to the first liquid side communication pipe (21) side in the refrigerant passage (205) as in the second heating operation. And the controller (240) stops the operation of the subcooling compressor (221). [0169] If the detection value of the first refrigerant temperature sensor (237) and the detection value of the second refrigerant temperature sensor (238) during the operation of the subcooling compressor (221) are almost the same, For example, it can be determined that the refrigerant is not flowing in the refrigerant passage (205) as in the first heating operation, and the controller (240) stops the operation of the supercooling compressor (221).

[0170] In the controller (240) of the present modification, the difference between the detection value of the first refrigerant temperature sensor (237) and the detection value of the second refrigerant temperature sensor (238) is determined by the refrigerant in the refrigerant passage (205). May be used as a distribution status display value indicating the distribution status of the product. That is, if the value obtained by subtracting the detection value of the second refrigerant temperature sensor (238) from the detection value of the first refrigerant temperature sensor (237) is negative, the detection value of the first refrigerant temperature sensor (237) is Since it can be determined that the state is lower than the detection value of the temperature sensor (238), the controller (240) continues the operation of the subcooling compressor (221). If the value obtained by subtracting the detection value of the second refrigerant temperature sensor (238) from the detection value of the first refrigerant temperature sensor (237) is zero or more, the detection value of the first refrigerant temperature sensor (237) (2) The controller (240) stops the subcooling compressor (221) because it is higher than the detection value of the refrigerant temperature sensor (238) or it can be determined that both are in the same state.

[0171] Modification 2 of one embodiment

In the subcooling unit (200) of the present embodiment, as shown in FIG. 8, a flow meter (251) is provided in the refrigerant passage (205), and a subcooling compressor is provided based on a detection value of the flow meter (251). Operation control of (221) may be performed.

[0172] In the supercooling unit (200), the detection value of the flow meter (251) is input to the controller (240). The controller (240) determines the flow direction of the refrigerant in the refrigerant passage (205) and whether the refrigerant is flowing in the refrigerant passage (205) based on the detection value of the flow meter (251). I do. That is, the controller (240) uses the detection value of the flow meter (251) as a circulation state display value indicating the circulation state of the refrigerant in the refrigerant passage (205).

[0173] During operation of the subcooling compressor (221), the refrigerant flows in the refrigerant passage (205) from the first liquid side communication pipe (21) to the second liquid side communication pipe (22). If the controller (240) determines that the subcooling compressor (221) is operating, the controller (240) continues to operate the supercooling compressor (221). During operation of the subcooling compressor (221), the refrigerant flows through the refrigerant passage (205) from the second liquid side communication pipe (22) to the first liquid side communication pipe (21). If it is determined that the compressor is If the controller (240) determines that the refrigerant is not flowing through the refrigerant passage (205) during the operation of ()), the controller (240) stops the operation of the subcooling compressor (221).

[0174] Modification 3 of one embodiment 3

The controller (240) of the present embodiment may control the operation of the subcooling compressor (221) based only on the detection value of the outside air temperature sensor (231).

[0175] The operation of the controller (240) will be described. When the detected value of the outside air temperature sensor (231) exceeds a predetermined upper limit (for example, 30 ° C), the cooling load in the refrigerated showcase (13) or the refrigerated showcase (14) or the air conditioning unit (12). It can be inferred that the cooling load of the vehicle has increased. Therefore, in such a case, if the subcooling compressor (221) is stopped, the controller (240) starts the subcooling compressor (221) and operates the subcooling compressor (221). If it is, the operation of the supercooling compressor (221) is continued. The refrigerant flowing in the refrigerant passage (205) from the first liquid side communication pipe (21) to the second liquid side communication pipe (22) is cooled by the supercooling heat exchanger (210) and then refrigerated. It is supplied to the showcase (13) and the like.

[0176] On the other hand, when the detection value of the outside air temperature sensor (231) falls below a predetermined lower limit (for example, 20 ° C), the cooling load in the refrigerated showcase (13) or the refrigerated showcase (14), or the air conditioning It can be estimated that the cooling load on the unit (12) is low, and it can be determined that the supercooling compressor (221) does not need to be operated. Therefore, in such a case, the controller (240) keeps the subcooling compressor (221) stopped while the subcooling compressor (221) is stopped, and the subcooling compressor (221). If is operating, stop the subcooling compressor (221).

[0177] Modification Example 4 of One Embodiment

The controller (240) of the present embodiment may control the operation of the subcooling compressor (221) based only on a change in the detection value of the refrigerant temperature detection means (236). The controller (240) of this modification uses the change in the detected value of the refrigerant temperature detecting means (236) as a flow state display value indicating the flow state of the refrigerant in the refrigerant passage (205).

[0178] The operation of the controller (240) will be described. If the detected value of the refrigerant temperature detecting means (236) gradually decreases from the time when the supercooling compressor (221) is started, the inside of the refrigerant passage (205) is connected to the first liquid side communication pipe (21). It can be determined that the refrigerant flows from to the second liquid side communication pipe (22) side. Therefore, in such a case, the controller (240) operates the supercooling compressor (2 Continue the operation of 21).

[0179] On the other hand, if the detected value of the refrigerant temperature detecting means (236) does not decrease even when the subcooling compressor (221) is started, the inside of the refrigerant passage (205) is passed through the second liquid side communication pipe ( It can be determined that the refrigerant is flowing from the 22) side to the first liquid side communication pipe (21) side, or that the refrigerant is not flowing in the refrigerant passage (205). Therefore, in such a case, the controller (240) stops the subcooling compressor (221).

[0180] If the detected value of the refrigerant temperature detecting means (236) gradually increases from the time when the subcooling compressor (221) is stopped, the first liquid side in the refrigerant passage (205) is moved. It can be determined that the refrigerant is flowing from the communication pipe (21) to the second liquid-side communication pipe (22). Therefore, in such a case, the controller (240) restarts the subcooling compressor (221).

[0181] On the other hand, if the detected value of the refrigerant temperature detecting means (236) does not rise even when the subcooling compressor (221) is stopped, the refrigerant passage (205) passes through the second liquid side communication pipe (22). ) Side to the first liquid side communication pipe (21) side, or it can be determined that the refrigerant is not flowing in the refrigerant passage (205). Therefore, in such a case, the controller (240) keeps the subcooling compressor (221) stopped.

[0182] Modification 5 of one embodiment 5

In the controller (240) of the present embodiment, the subcooling compressor (221) is based on the temperature difference between the subcooling refrigerant at the inlet and the outlet of the first flow path (211) of the subcooling heat exchanger (210). ) May be controlled.

[0183] As shown in Fig. 9, the supercooling unit (200) of the present modification is provided with a first supercooling refrigerant temperature sensor (252), a second subcooling refrigerant temperature sensor (253), and a force S. Can be In the subcooling refrigerant circuit (220), the first subcooling refrigerant temperature sensor (252) is provided immediately before the first flow path (211) of the subcooling heat exchanger (210). The temperature of the subcooling refrigerant flowing into the flow path (211) is detected. On the other hand, the second subcooling refrigerant temperature sensor (253) is provided immediately after the first flow path (211) of the supercooling heat exchanger (210) and flows out of the first flow path (211). The temperature of the immediately following subcooling refrigerant is detected. Then, the controller (240) of the present modified example compares the difference between the detection value of the first subcooling refrigerant temperature sensor (252) and the detection value of the second subcooling refrigerant temperature sensor (253) with the refrigerant passage (205). )) Use as a value.

[0184] The operation of the controller (240) will be described. During operation of the subcooling compressor (221), when the detection value of the second subcooling refrigerant temperature sensor (253) is higher than the detection value of the first subcooling refrigerant temperature sensor (252) (i.e., (2) If the detected value of the supercooling refrigerant temperature sensor (253) is positive (+) after subtracting the detection value of the first supercooling refrigerant temperature sensor (252), the refrigerant passage (205) It can be determined that the refrigerant is flowing from the first liquid side communication pipe (21) toward the second liquid side communication pipe (22). Therefore, in such a case, the controller (240) continues the operation of the subcooling compressor (221).

[0185] On the other hand, during the operation of the subcooling compressor (221), the detection value of the second subcooling refrigerant temperature sensor (253) is larger than the detection value of the first subcooling refrigerant temperature sensor (252). When the temperature is low or when there is no difference between them (that is, when the value obtained by subtracting the value detected by the first supercooling refrigerant temperature sensor (252) from the value detected by the second subcooling refrigerant temperature sensor (253) is less than or equal to zero) ), The force flowing through the refrigerant passage (205) from the second liquid-side communication pipe (22) to the first liquid-side communication pipe (21), or the inside of the refrigerant passage (205). It can be determined that no refrigerant is flowing. Therefore, in such a case, the controller (240) stops the subcooling compressor (221).

[0186] Modification 6 of One Embodiment

The controller (240) of the present embodiment may control the operation of the subcooling compressor (221) based only on the detection value of the suction pressure sensor (234). The detection value of the suction pressure sensor (234) is substantially equal to the refrigerant pressure in the first flow path (211) of the subcooling heat exchanger (210), that is, the evaporation pressure of the subcooling refrigerant. Therefore, in this modified example, the suction pressure sensor (234) constitutes the evaporating pressure detecting means. Then, the controller (240) of the present modification uses the detection value of the suction pressure sensor (234) as a flow state display value indicating the flow state of the refrigerant in the refrigerant path (205).

[0187] The operation of the controller (240) will be described. If the detected value of the suction pressure sensor (234) exceeds a predetermined reference value (for example, 0.2 MPa) during the operation of the subcooling compressor (221), the first flow of the subcooling heat exchanger (210) This means that the supercooling refrigerant has evaporated in the path (211), and it can be determined that the refrigerant is flowing in the refrigerant passage (205). So, in such a case, the controller (240) Continues the operation of the subcooling compressor (221).

[0188] On the other hand, if the detected value of the suction pressure sensor (234) is less than or equal to the reference value during the operation of the subcooling compressor (221), the first subcooling heat exchanger (210) This means that the supercooling refrigerant has hardly evaporated in the flow path (211), and it can be determined that the refrigerant is not flowing in the refrigerant path (205). Therefore, in such a case, the controller (240) stops the subcooling compressor (221).

[0189] Modification 7 of One Embodiment

The controller (240) of the present embodiment controls the operation of the subcooling compressor (221) based only on the difference between the detected value Tout of the refrigerant temperature sensor (236) and the evaporation temperature Tg of the subcooling refrigerant. I'll do it. The controller (240) according to the present modification uses the difference between the detected value Tout of the refrigerant temperature sensor (236) and the evaporation temperature Tg of the subcooling refrigerant as a distribution state display indicating the refrigerant distribution state in the refrigerant passage (205). Use as a value.

[0190] The operation of the controller (240) will be described. During the operation of the supercooling compressor (221), the value obtained by subtracting the evaporation temperature Tg of the supercooling refrigerant from the detection value Tout of the refrigerant temperature sensor (236) becomes equal to or less than a predetermined reference value (for example, 15 ° C). In this case, it can be determined that the refrigerant is flowing in the refrigerant passage (205) from the first liquid side communication pipe (21) toward the second liquid side communication pipe (22). Therefore, in such a case, the controller (240) continues the operation of the subcooling compressor (221).

[0191] On the other hand, during operation of the subcooling compressor (221), a value obtained by subtracting the evaporation temperature Tg of the supercooling refrigerant from the detection value Tout of the refrigerant temperature sensor (236) is equal to or less than the reference value. In this case, the force flowing through the refrigerant passage (205) from the second liquid-side communication pipe (22) toward the first liquid-side communication pipe (21), or the refrigerant passage (205) It can be determined that the refrigerant is not flowing inside. Therefore, in such a case, the controller (240) stops the subcooling compressor (221).

[0192] Modification 8 of One Embodiment

The controller (240) of the present embodiment may control the operation of the supercooling compressor (221) based only on the detected value of the refrigerant temperature detecting means (236). The controller (240) of the present modified example converts the detected value of the refrigerant temperature detecting means (236) into the refrigerant flow state in the refrigerant passage (205). It is used as a distribution status display value indicating the status.

[0193] The operation of the controller (240) will be described. If the detected value of the refrigerant temperature detecting means (236) is higher than a predetermined reference value while the subcooling compressor (221) is stopped, the outdoor unit (11) is operated on the side of use of the refrigerated showcase (13) or the like. It can be guessed that the temperature of the refrigerant sent to the refrigeration system is increasing, and that the cooling capacity of the refrigerated showcase (13) and the like is becoming insufficient. Therefore, in such a case, the controller (240) starts the subcooling compressor (221).

[0194] On the other hand, if the detected value of the refrigerant temperature detecting means (236) becomes lower than the predetermined reference value while the subcooling compressor (221) is stopped, the outdoor unit (11) refrigerates the refrigerant. It can be assumed that the cooling capacity of the refrigerated showcase (13) or the like where the temperature of the refrigerant sent to the use side of the showcase (13) or the like is not so high can be sufficiently secured. Therefore, in such a case, the controller (240) keeps the subcooling compressor (221) stopped.

[0195] Modification of one embodiment 91

The controller (240) of the present embodiment controls the operation of the subcooling compressor (221) based on the difference between the detected value of the refrigerant temperature detecting means (236) and the detected value of the outside air temperature sensor (231). Even though. The controller (240) of the present modification is configured to display a difference between the detected value of the refrigerant temperature detecting means (236) and the detected value of the outside air temperature sensor (231) as a distribution state display indicating the refrigerant distribution state in the refrigerant passage (205). Use as a value.

[0196] The operation of the controller (240) will be described. When the refrigerant flows from the first liquid side communication pipe (21) side to the second liquid side communication pipe (22) side in the refrigerant passage (205), the refrigerant is discharged to the outdoor air by the outdoor heat exchanger (44). Although the refrigerant that has radiated heat and condensed flows into the refrigerant passage (205), the temperature of the refrigerant cannot be lower than the temperature of the outdoor air. For this reason, while the subcooling compressor (221) is stopped, the value obtained by subtracting the detection value of the outside air temperature sensor (231) from the detection value of the refrigerant temperature detection means (236) exceeds the predetermined reference value. In this case, it can be determined that the refrigerant flows from the first liquid-side communication pipe (21) toward the second liquid-side communication pipe (22) in the refrigerant passage (205). Therefore, in such a case, the controller (240) starts the subcooling compressor (221).

On the other hand, while the subcooling compressor (221) is stopped, the value obtained by subtracting the detection value of the outside air temperature sensor (231) from the detection value of the refrigerant temperature detection means (236) becomes equal to or less than a predetermined reference value. And When the refrigerant flows in the refrigerant passage (205) from the second liquid-side communication pipe (22) toward the first liquid-side communication pipe (21), It can be determined that the refrigerant is not flowing inside. Therefore, in such a case, the controller (240) keeps the subcooling compressor (221) stopped.

[0198]-Modification 10 of Embodiment-In the supercooling unit (200) of the present embodiment, the supercooling refrigerant circuit (220) is configured to allow natural circulation of the refrigerant. Yeah.

[0199] As shown in Fig. 10, in the subcooling refrigerant circuit (220) of this variation, the subcooling outdoor heat exchanger (222) is arranged above the subcooling heat exchanger (210). Have been. Further, a bypass pipe (224) is provided in the subcooling refrigerant circuit (220). One end of the bypass pipe (224) is connected to the suction side of the subcooling compressor (221), and the other end is connected to the discharge side of the subcooling compressor (221). Further, the non-pass pipe (224) is provided with a check valve (225) that allows only the flow of the refrigerant directed toward one end and the other end.

[0200] In the subcooling refrigerant circuit (220), the supercooling refrigerant circulates by operating the outdoor fan (230) even while the subcooling compressor (221) is stopped. Specifically, when the outdoor fan (230) is operated, in the subcooling outdoor heat exchanger (222), the refrigerant radiates heat to outdoor air and condenses. The subcooling refrigerant condensed in the subcooling outdoor heat exchanger (222) flows down due to gravity, passes through the subcooling expansion valve (223) that is set to the fully open state, and passes through the subcooling heat exchanger (210). ) To the first channel (211). In the first flow path (211) of the subcooling 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) returns to the supercooling outdoor heat exchanger (222) through the bypass pipe (224), exchanges heat with outdoor air, and condenses again. .

[0201] When starting the supercooling unit (200), the controller (240) of the present modification first starts the outdoor fan (230), and supercools while the outdoor fan (230) is operating. It is determined whether or not to start the compressor (221). That is, when the controller (240) determines that the refrigerant flowing in the refrigerant passage (205) needs to be cooled, only the outdoor fan (230) is started while the supercooling compressor (221) is stopped. I do. When the outdoor fan (230) is started, the subcooling refrigerant naturally circulates in the refrigerant passage (205) and subcools in the subcooling heat exchanger (210). The refrigerant in the second flow path (212) is cooled by the refrigerant for use. The controller (240) continues to operate only the outdoor fan (230) for a predetermined time (for example, 5 minutes), and thereafter, the cooling of the refrigerant flowing in the refrigerant passage (205) becomes insufficient. Is determined. Then, if the cooling of the refrigerant flowing in the refrigerant passage (205) is insufficient, the controller (240) activates the supercooling compressor (221).

When the subcooling compressor (221) is started, a refrigeration cycle is performed in the subcooling refrigerant circuit (220). On the other hand, if the cooling of the refrigerant is not insufficient, the controller (240) continues only the operation of the outdoor fan (230) with the subcooling compressor (221) stopped.

[0202] In this modification, the supercooling compressor (221) is started only when the cooling of the heat-source-side refrigerant is insufficient by simply circulating the supercooling refrigerant by the operation of the outdoor fan (230). Like that. For this reason, it is possible to avoid a situation in which the supercooling compressor (221) is started in spite of the fact that the supercooling compressor (221) does not need to be started. Can be reduced. As a result, the time during which the subcooling compressor (221) is operated in an unstable transient state can be reduced, and the reliability of the subcooling compressor (221) can be improved.

[0203] Modification 11 of one embodiment

In the subcooling unit (200) of the present embodiment, a chilled water circuit through which chilled water flows may be provided as a cooling fluid circuit instead of the subcooling refrigerant circuit (220). In this chilled water circuit, relatively low-temperature water, for example, at about 5 ° C flows. In the supercooling heat exchanger (210) of the present modification, a chilled water circuit is connected to the first flow path (211), and the chilled water flowing in the first flow path (211) flows through the second flow path (212). Exchange heat with the refrigerant flowing through the heat exchanger.

[0204] The above embodiments are essentially preferred examples, and are not intended to limit the scope of the present invention, its application, or its use.

Industrial applicability

[0205] As described above, the present invention is useful for a subcooling device that cools a refrigerant sent from a heat source unit of a refrigerating device to a use unit.

Claims

The scope of the claims

[1] A refrigeration unit (10) that circulates the heat source side refrigerant between the heat source unit (11) and the utilization units (12, 13, 14) connected by the communication pipe to perform a refrigeration cycle, A supercooling device for cooling the heat source side refrigerant of the refrigerating device (10) sent from 11) to the use units (12, 13, 14),

A refrigerant passage (205) connected to the liquid-side communication pipe (21, 22) of the refrigeration system (10); a cooling fluid circuit (220) through which a cooling fluid flows;

A supercooling heat exchanger (210) for cooling the heat source side refrigerant in the refrigerant passage (205) by exchanging heat with the cooling fluid, and

Control means (240) for controlling the flow state of the cooling fluid in the cooling fluid circuit (220) according to the flow state of the heat source side refrigerant in the refrigerant passage (205);

A supercooling device comprising:

[2] In claim 1,

The cooling fluid circuit includes a supercooling refrigerant circuit (220) .The supercooling refrigerant circuit (220) includes a supercooling compressor (221), and includes a supercooling compressor (221). Refrigeration cycle by circulating cooling refrigerant

A supercooling device characterized by the above-mentioned.

[3] In claim 2,

The control means (240) is configured to control the operation of the subcooling compressor (221) to control the circulation state of the supercooling refrigerant in the subcooling refrigerant circuit (220). Is

A supercooling device characterized by the above-mentioned.

[4] In claim 3,

The control means (240) controls the flow direction of the heat source-side refrigerant in the refrigerant passage (205) and the flow of the heat source-side refrigerant in the refrigerant passage (205) during operation of the subcooling compressor (221). Is detected as the flow state of the heat source side refrigerant, and in the state where the heat source side refrigerant flows from the heat source unit (11) to the utilization unit (12, 13, 14) in the refrigerant passage (205), the subcooling compressor Continue the operation of (221), and use the heat source unit (12, 13, 14) from the utilization unit (12, 13, 14) in the refrigerant passage (205). The supercooling compressor (221) is configured to stop the supercooling compressor (221) in a state where the heat source side refrigerant flows toward the heat source (11) and a state where the heat source side refrigerant does not flow in the refrigerant passage (205).

A supercooling device characterized by the above-mentioned.

[5] In claim 4,

The control means (240) is configured to start the subcooling compressor (221) when a predetermined time has elapsed from the time when the supercooling compressor (221) was stopped.

A supercooling device characterized by the above-mentioned.

[6] In claim 3, 4 or 5,

A refrigerant temperature detecting means (236) for detecting the temperature of the heat source side refrigerant in a portion of the refrigerant passage (205) closer to the utilization unit (12, 13, 14) than the subcooling heat exchanger (210). ,

The control means (240) determines the flow state of the heat source side refrigerant based on a change in the detected value of the refrigerant temperature detecting means (236) from the time when the supercooling compressor (221) is started. It is configured

A supercooling device characterized by the above-mentioned.

[7] In claim 3, 4 or 5,

Refrigerant temperature detecting means (236) for detecting the temperature of the heat source side refrigerant in a portion of the refrigerant passage (205) closer to the utilization unit (12, 13, 14) than the supercooling heat exchanger (210); An evaporating temperature detecting means (234) for detecting an evaporating temperature of the subcooling refrigerant in the subcooling heat exchanger (210),

The control means (240) is configured to determine the circulation state of the heat source side refrigerant based on the detection value of the refrigerant temperature detection means (236) and the detection value of the evaporation temperature detection means (234). ing

A supercooling device characterized by the above-mentioned.

[8] In claim 3, 4 or 5,

First refrigerant temperature detecting means (237) for detecting the temperature of the heat source side refrigerant in a portion of the refrigerant passage (205) closer to the utilization unit (12, 13, 14) than the subcooling heat exchanger (210); , A second refrigerant temperature detecting means (238) for detecting the temperature of the heat source side refrigerant in a portion of the refrigerant passage (205) closer to the heat source unit (11) than the supercooling heat exchanger (210).

The control means (240) determines the circulation state of the heat source side refrigerant based on the detection value of the first refrigerant temperature detection means (237) and the detection value of the second refrigerant temperature detection means (238). Is configured to

A supercooling device characterized by the above-mentioned.

[9] In claim 1, 2 or 3,

The refrigerant passage (205) is provided with a flow meter (251) for detecting the flow rate of the heat source side refrigerant.

The control means (240) uses the detected value of the flow meter (251) as a flow state display value indicating the flow state of the heat source side refrigerant, and the cooling fluid flows through the cooling fluid circuit (220). In this state, whether to continue or stop the flow of the cooling fluid is determined based on the flow state display value.

A supercooling device characterized by the above-mentioned.

[10] In claim 1, 2 or 3,

First refrigerant temperature detecting means (237) for detecting the temperature of the heat source side refrigerant in a portion of the refrigerant passage (205) closer to the utilization unit (12, 13, 14) than the subcooling heat exchanger (210); A second refrigerant temperature detecting means (238) for detecting the temperature of the heat source side refrigerant in a portion of the refrigerant passage (205) closer to the heat source unit (11) than the supercooling heat exchanger (210). ,

The control means (240) determines a difference between the detection value of the first refrigerant temperature detection means (237) and the detection value of the second refrigerant temperature detection means (238) as a distribution state indicating the circulation state of the heat source side refrigerant. It is used as a display value, and in the state where the cooling fluid is flowing in the cooling fluid circuit (220), whether to continue or stop the flow of the cooling fluid is determined based on the flow state display value. It is composed to decide

A supercooling device characterized by the above-mentioned.

[11] In claim 1, 2 or 3, A refrigerant temperature detecting means (236) for detecting the temperature of the heat source side refrigerant in a portion of the refrigerant passage (205) closer to the utilization unit (12, 13, 14) than the subcooling heat exchanger (210). ,

The control means (240) uses a change in the detected value of the refrigerant temperature detection means (236) as a flow state display value indicating a flow state of the heat source side refrigerant, and the cooling fluid is supplied to the cooling fluid circuit (220). A supercooling device characterized in that it is configured to determine whether to continue or stop the flow of the cooling fluid in the flowing state based on the flow state display value.

[12] In claim 1, 2 or 3,

The cooling fluid circuit (220) includes an inlet-side fluid temperature detecting means (252) for detecting the temperature of the cooling fluid at the inlet of the subcooling heat exchanger (210), and the subcooling heat exchanger ( 2) An outlet fluid temperature detecting means (253) for detecting the temperature of the cooling fluid at the outlet of 10) is provided.

The control means (240) determines the difference between the detected value of the inlet-side fluid temperature detecting means (252) and the detected value of the outlet-side fluid temperature detecting means (253) as a flow state indicating the flow state of the heat source side refrigerant. In the state where the cooling fluid is flowing in the cooling fluid circuit (220), whether to continue or stop the flow of the cooling fluid is used as the display value based on the flow status display value. It is configured to determine

A supercooling device characterized by the above-mentioned.

[13] In claim 2 or 3,

The subcooling refrigerant circuit (220) is provided with evaporating pressure detecting means (234) for detecting the evaporating pressure of the subcooling refrigerant in the subcooling heat exchanger (210).

The control means (240) uses the detected value of the evaporating pressure detection means (234) as a flow state display value indicating the flow state of the heat source side refrigerant, and uses the supercooled refrigerant circuit (220) A supercooling device configured to determine whether to continue or stop the circulation of the subcooling refrigerant in a state where the refrigerant is circulating, based on the flow state display value.

[14] In claim 2 or 3, Refrigerant temperature detecting means (236) for detecting the temperature of the heat source side refrigerant in a portion of the refrigerant passage (205) closer to the utilization unit (12, 13, 14) than the supercooling heat exchanger (210); An evaporating temperature detecting means (234) for detecting an evaporating temperature of the subcooling refrigerant in the subcooling heat exchanger (210),

The control means (240) uses the difference between the detected value of the refrigerant temperature detecting means (236) and the detected value of the evaporation temperature detecting means (234) as a flow state display value indicating the flow state of the heat source side refrigerant. In the state where the subcooling refrigerant is circulating in the subcooling refrigerant circuit (220), whether to continue or stop the circulation of the subcooling refrigerant is determined based on the flow state display value, Is configured to determine

A supercooling device characterized by the above-mentioned.

[15] In claim 1, 2 or 3,

The control means (240) uses the detected value of the refrigerant temperature detecting means (236) as a flow state display value indicating the flow state of the heat source side refrigerant, and controls the flow of the cooling fluid in the cooling fluid circuit (220). In a state in which the cooling fluid is stopped, it is configured to determine whether to start or stop the flow of the cooling fluid based on the flow state display value. Cooling system.

[16] In claim 1, 2 or 3,

The control means (240) uses a change in the detected value of the refrigerant temperature detection means (236) as a flow state display value indicating a flow state of the heat source side refrigerant, and uses the cooling fluid in the cooling fluid circuit (220). In the state where the circulation of the cooling fluid is stopped, it is configured to determine whether to start or stop the circulation of the cooling fluid based on the above-mentioned circulation state display value. A supercooling device characterized by the above-mentioned.

[17] In claim 2 or 3,

Outdoor temperature detecting means (231) for detecting the temperature of outdoor air,

Refrigerant temperature detecting means (236) for detecting the temperature of the heat source side refrigerant in a portion closer to the utilization unit (12, 13, 14) than the subcooling heat exchanger (210) in the refrigerant passage (205). While

The control means (240) uses the difference between the detected value of the refrigerant temperature detecting means (236) and the detected value of the outdoor temperature detecting means (231) as a distribution state display value indicating the distribution state of the heat source side refrigerant. In the state where the circulation of the subcooling refrigerant is stopped in the subcooling refrigerant circuit (220), whether the circulation of the supercooling refrigerant is started or stopped is determined by the distribution state display value. It is configured to be determined on the basis of

A supercooling device characterized by the above-mentioned.

[18] A refrigeration system (10) that circulates the heat source side refrigerant between the heat source unit (11) and the utilization units (12, 13, 14) connected by the communication pipe to perform a refrigeration cycle, A supercooling device for cooling the heat source side refrigerant of the refrigerating device (10) sent from 11) to the use units (12, 13, 14),

While the heat source unit (11) of the refrigerating device (10) is configured to exchange heat with the outdoor air at the heat source side,

Control means (240) for controlling a flow state of the cooling fluid in the cooling fluid circuit (220) in accordance with a detection value of the outdoor temperature detecting means (231);

A supercooling device comprising:

[19] In claim 18,

The cooling fluid circuit is configured by a supercooling refrigerant circuit (220), The supercooling refrigerant circuit (220) includes a supercooling compressor (221), and performs a refrigeration cycle by circulating a supercooling refrigerant as a cooling fluid.

A supercooling device characterized by the above-mentioned.

[20] In claim 18 or 19,

The controller (240) determines whether to continue or stop the flow of the cooling fluid while the cooling fluid is flowing in the cooling fluid circuit (220). Is configured to be determined based on the detection value of

A supercooling device characterized by the above-mentioned.

[21] In claim 18 or 19,

The control means (240) determines whether to start or stop the flow of the cooling fluid in a state where the flow of the cooling fluid in the cooling fluid circuit (220) is stopped. A supercooling device configured to be determined based on a detection value of a detection means (231).

[22] In claim 2 or 19,

A heat-dissipating heat exchanger (222) connected to the supercooling refrigerant circuit (220) to exchange heat between the supercooling refrigerant and outdoor air;

An outdoor fan (230) for supplying outdoor air to the heat-radiating heat exchanger (222), wherein the subcooling refrigerant circuit (220) is connected to the subcooling compressor (221) while the subcooling compressor (221) is stopped. By operating the external fan (230), a natural circulation operation that allows the subcooling refrigerant to circulate naturally is possible,

When starting the circulation of the subcooling refrigerant, the control means (240) activates the outdoor fan (230) to cause the subcooling refrigerant circuit (220) to perform a natural circulation operation. It is configured to determine whether to start or keep stopping the subcooling compressor (221) according to the flow state of the heat source side refrigerant in the refrigerant passage (205) during the ring operation. Characterized subcooling device.