Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B1/00—Compression machines, plants or systems with non-reversible cycle
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B13/00—Compression machines, plants or systems, with reversible cycle
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B40/00—Subcoolers, desuperheaters or superheaters
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B40/00—Subcoolers, desuperheaters or superheaters
  • F25B40/02—Subcoolers
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B49/00—Arrangement or mounting of control or safety devices
  • F25B49/02—Arrangement or mounting of control or safety devices for compression type machines, plants or systems
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B2313/00—Compression machines, plants or systems with reversible cycle not otherwise provided for
  • F25B2313/023—Compression machines, plants or systems with reversible cycle not otherwise provided for using multiple indoor units
  • F25B2313/0233—Compression machines, plants or systems with reversible cycle not otherwise provided for using multiple indoor units in parallel arrangements
  • F25B2313/02331—Compression machines, plants or systems with reversible cycle not otherwise provided for using multiple indoor units in parallel arrangements during cooling
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
  • F25B2400/22—Refrigeration systems for supermarkets
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B2700/00—Sensing or detecting of parameters; Sensors therefor
  • F25B2700/21—Temperatures
  • F25B2700/2103—Temperatures near a heat exchanger
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B2700/00—Sensing or detecting of parameters; Sensors therefor
  • F25B2700/21—Temperatures
  • F25B2700/2106—Temperatures of fresh outdoor air

Definitions

• the present invention relates to a refrigeration apparatus, and more particularly, to a measure for improving the performance and reliability of a refrigeration apparatus provided with a refrigerant circuit for performing a two-stage compression refrigeration cycle.
• This supercooling device is attached to an air conditioner including an outdoor unit and an indoor unit.
• the subcooling device is provided in the middle of a liquid-side connecting pipe connecting the outdoor unit and the indoor unit, and includes a subcooling refrigerant circuit.
• This subcooling device performs a refrigeration cycle by circulating the refrigerant in a subcooling refrigerant circuit, 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 increases the cooling capacity by reducing the enthalpy of the liquid refrigerant sent to the indoor unit.
• 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 load condition of the air conditioner is input to the control unit of the air conditioner.
• operation control is performed based on a signal input to the control unit of the air conditioner. For example, if it is determined from the input signal that the cooling load is large, the supercooling device starts operation to increase the cooling capacity of the air conditioner, and if it is determined that the cooling load is small, the supercooling device stops the operation. Stop. That is, the supercooling device appropriately adjusts the cooling capacity by transmitting and receiving signals to and from the air conditioner.
• the subcooling device is installed in the refrigeration device.
• wiring work for transmitting signals transmitted and received between the two was required, and there was a problem that installation work of the supercooling device was complicated.
• erroneous wiring may occur in the wiring work, and there is a possibility that such a human error may cause a trouble.
• the present invention has been made in view of its power, 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. And to simplify the installation work of the supercooling device, and to prevent human error during the installation work.
• a first solution is to circulate a refrigerant between a heat source unit (11) and a utilization unit (12, 13, 14) connected by a communication pipe to form a vapor compression refrigeration cycle. It is assumed that a supercooling device that is attached to a refrigeration system (10) that performs cooling and that also transmits the power of the heat source unit (11) to the utilization units (12, 13, 14) to cool the refrigerant of the refrigeration system (10).
• a refrigerant passage (205) connected to the liquid-side communication pipe of the cooling device (10), and a supercooling heat exchange for cooling the refrigerant in the refrigerant passage (205) by exchanging heat with a cooling fluid.
• a cooling fluid circuit (220) having a cooling passage (210) and a cooling temperature of the cooling medium in the refrigerant passage (205) in the supercooling heat exchanger (210). Control means (240) for adjusting based on conditions.
• the refrigerant flows between the heat source unit (11) and the utilization units (12, 13, 14) through the communication pipe.
• the refrigerant passage (205) of the subcooling device is connected to the liquid-side communication pipe (21, 22) of the refrigeration device (10), and the refrigerant of the refrigeration device (10) flows through the inside thereof.
• a cooling fluid such as refrigerant, water, or air flows.
• the refrigerant of the refrigerating device (10) flowing in the refrigerant passage (205) exchanges heat with the cooling fluid.
• the cooling fluid absorbs heat from the refrigerant in the refrigeration system (10) and evaporates, and the refrigerant in the refrigeration system (10) is cooled.
• the control means (240) determines whether the outside air temperature ⁇ the refrigerant flow rate.
• the cooling temperature of the refrigerant of the cooling device (10) flowing in the refrigerant passage (205) is adjusted based on the surrounding conditions of the supercooling heat exchanger (210). For example, when the ambient temperature of the supercooling heat exchanger (210) is set to the outside air temperature, the cooling temperature of the refrigerant is lowered when the outside air temperature is high, and the cooling of the refrigerant is performed when the outside air temperature is low. Adjust so that the temperature rises.
• the operation control suitable for the load condition is performed by adjusting according to the surrounding conditions. .
• the cooling capacity of the subcooling device is adjusted without receiving the signal regarding the load state or the like from the refrigeration device (10).
• a second solution is the first solution of the first aspect, wherein the control means (240) is configured so that the control means (240) sets a subcooling heat exchanger (210) in advance according to ambient conditions.
• the target cooling temperature of the refrigerant of the refrigeration system (10) according to the ambient conditions of the supercooling heat exchanger (210) such as the outside air temperature, that is, the load state is set in advance. For example, if the outside air temperature is high, the target cooling temperature is set lower, and if the outside air temperature is low, the target cooling temperature is set higher.
• the target cooling temperature is low in the control unit (242)
• the flow rate of the cooling fluid such as the refrigerant and the water in the supercooling heat exchanger (210) is increased.
• the amount of heat exchange between the refrigerant of the refrigerating device (10) and the cooling fluid in the supercooling heat exchanger (210) also increases, so that the refrigerant of the refrigerating device (10) is further cooled.
• the control unit (242) when the target cooling temperature is high, the flow rate of the cooling fluid such as the refrigerant and the water in the supercooling heat exchange (210) is reduced. As a result, the amount of heat exchange in the supercooling heat exchanger (210) also decreases, so that the refrigerant in the refrigeration system (10) is not cooled so much.
• the cooling fluid circuit includes a supercooling compressor (221) having a variable capacity and a heat source side heat exchanger (222).
• the control section (242) of the control means (240) controls the operating frequency of the subcooling compressor (221) based on the target cooling temperature, thereby controlling the subcooling.
• the flow rate of the subcooling refrigerant flowing through the heat exchanger (210) is adjusted.
• the cooling fluid circuit constitutes a subcooling refrigerant circuit (220), and the refrigerant discharged from the supercooling compressor (221) is a heat source in the subcooling refrigerant circuit (220).
• the side heat exchange (222) exchanges heat with, for example, air, and then exchanges heat with the refrigerant in the refrigerant passage (205) in the subcooling heat exchanger (210) and returns to the subcooling compressor (221) again. repeat.
• the target cooling temperature is low in the control unit (242
• the operating frequency of the subcooling compressor (221) is increased to increase the subcooling refrigerant flowing through the subcooling heat exchanger (210).
• Increase flow rate In the control unit (242), when the target cooling temperature is high, the operating frequency of the subcooling compressor (221) is reduced to reduce the supercooling refrigerant flowing through the subcooling heat exchanger (210). Decrease flow rate.
• the cooling fluid circuit includes a supercooling compressor (221) having a variable capacity and a heat source side heat exchanger (222).
• the control unit (242) of the control means (240) controls the operating frequency of the fan (230) of the heat source side heat exchanger (222) based on the target cooling temperature, thereby controlling the operation frequency of the fan (230).
• the flow rate of the subcooling refrigerant flowing through the subcooling heat exchanger (210) is adjusted.
• the refrigerant discharged from the supercooling compressor (221) is mixed with air taken in by the fan (230) in the heat source side heat exchanger (222).
• the heat exchange is performed, and thereafter, the heat exchange with the refrigerant in the refrigerant passage (205) is performed by the supercooling heat exchange (210), and the circulation returning to the supercooling compressor (221) is repeated.
• the target cooling temperature is low in the control section (242)
• the operating frequency of the fan (230) of the heat source side heat exchanger (222) is reduced to reduce the supercooling heat exchanger (210). )
• the operating frequency of the fan (230) of the heat source side heat exchanger (222) is increased to activate the subcooling heat exchanger (210). Reduce the flow rate of the subcooling refrigerant that flows.
• a fifth solution is the above-mentioned third solution, wherein the control section (242) of the control means (240) is configured to perform cooling with the target cooling temperature and the supercooling heat exchanger (210).
• the operating frequency of the subcooling compressor (221) is controlled based on the difference from the temperature of the refrigerant in the refrigerant passage (205).
• the operating frequency of the subcooling compressor (221) is increased to increase the subcooling heat.
• the cooling temperature of the refrigerant in the exchanger (210) is reduced.
• the present invention also adjusts the cooling capacity of the subcooling device without receiving a signal related to the load state or the like from the refrigeration device (10). Is surely performed.
• control section (242) of the control section (240) includes the target cooling temperature and the subcooling refrigerant circuit (220).
• the operating frequency of the supercooling compressor (221) is controlled based on the difference from the set temperature determined by the saturation temperature corresponding to the low pressure of the refrigerant for use.
• a set temperature regarded as the temperature of the refrigerant after being cooled by the supercooling heat exchanger (210) is determined from the saturation temperature corresponding to the low pressure of the subcooling refrigerant. Therefore, even if a signal regarding the load state of the refrigeration system (10) is not received, almost the same information as the actual temperature of the cooled refrigerant is obtained, and the cooling capacity is reliably adjusted.
• a seventh solution is the above-mentioned third solution, wherein the control section (242) of the control means (240) is configured to control the target cooling temperature and the suction temperature of the subcooling compressor (221).
• the operating frequency of the subcooling compressor (221) is controlled based on the difference between the set temperature and the set temperature.
• the set temperature regarded as the temperature of the refrigerant after being cooled by the subcooling heat exchanger (210) is determined from the suction temperature of the subcooling compressor (221). Therefore, even if a signal regarding the load state of the refrigeration system (10) is not received, almost the same information as the actual temperature of the cooled refrigerant is obtained, and the cooling capacity is reliably adjusted.
• an eighth solution of the present invention is the same as the fourth solution, wherein the control unit (242) of the control means (240) includes a target cooling temperature and a subcooling heat exchanger (210). )), The operating frequency of the fan (230) is controlled based on the difference from the temperature of the refrigerant in the refrigerant passage (205). [0024] In the above solution, when the temperature of the refrigerant in the refrigerant passage (205) after being cooled is higher than the target cooling temperature, the operating frequency of the fan (230) is reduced to change the subcooling heat exchanger (210). ) To reduce the cooling temperature of the refrigerant.
• the operating frequency of the fan (230) is increased to increase the temperature of the refrigerant in the supercooling heat exchanger (210). Increase the cooling temperature. Therefore, the cooling capacity is surely adjusted by obtaining the actual temperature of the cooled refrigerant as information. Further, since the temperature of the refrigerant after being cooled is information obtained by a temperature sensor or the like in the subcooling device, in the present invention, the cooling capacity of the subcooling device without receiving a signal regarding the load state from the refrigeration device (10) is also provided. Adjustments are made reliably.
• control section (242) of the control means (240) comprises a target cooling temperature and a subcooling refrigerant circuit (220).
• the operating frequency of the fan (230) is controlled based on the difference from the set temperature determined by the saturation temperature corresponding to the low pressure pressure of the subcooling refrigerant.
• the set temperature regarded as the temperature of the refrigerant after being cooled by the supercooling heat exchanger (210) is determined from the saturation temperature corresponding to the low pressure of the subcooling refrigerant. Therefore, even if a signal regarding the load state of the refrigeration system (10) is not received, almost the same information as the actual temperature of the cooled refrigerant is obtained, and the cooling capacity is reliably adjusted.
• a tenth solution is the control according to the fourth solution, wherein the control section (242) of the control means (240) determines the target cooling temperature and the suction temperature of the subcooling compressor (221). The operating frequency of the fan (230) is controlled based on the difference from the set temperature.
• a set temperature regarded as the temperature of the refrigerant after being cooled by the subcooling heat exchanger (210) is determined from the suction temperature of the subcooling compressor (221). Therefore, even if a signal regarding the load state of the refrigeration system (10) is not received, almost the same information as the actual temperature of the cooled refrigerant is obtained, and the cooling capacity is reliably adjusted.
• An eleventh solution is the heat exchanger for supercooling according to the first solution, wherein
• the ambient condition of (210) is the outside air temperature.
• the cooling temperature of the refrigerant in the refrigerant passage (205) in the supercooling heat exchanger (210) is adjusted based on the outside air temperature. For example, when the outside air temperature is high, The cooling temperature of the refrigerant is adjusted to be low, and when the outside air temperature is low, the cooling temperature of the refrigerant is adjusted to be high. That is, the control means (240) determines the load state of the refrigeration system (10) based on the outside air temperature.
• a twelfth solution is the heat exchanger for supercooling according to the first solution.
• the surrounding condition of (210) is the flow rate of the refrigerant in the refrigerant passage (205).
• the cooling temperature of the refrigerant in the refrigerant passage (205) in the supercooling heat exchanger (210) is adjusted based on the actual refrigerant flow rate in the refrigerant passage (205). For example, when the flow rate of the refrigerant is large, the cooling temperature of the refrigerant is adjusted to be low, and when the flow rate of the refrigerant is small, the cooling temperature of the refrigerant is adjusted to be increased. That is, the control means (240) determines the load state of the refrigeration system (10) based on the coolant flow rate.
• a thirteenth solution of the above-mentioned first solution is the supercooling heat exchanger.
• the ambient condition of (210) is the temperature of the refrigerant in the refrigerant passage (205) before being cooled by the subcooling heat exchanger (210), or the refrigerant after being cooled by the supercooling heat exchanger (210).
• the cooling temperature of the refrigerant in the refrigerant passage (205) in the supercooling heat exchanger (210) is adjusted based on the actual refrigerant temperature before or after the cooling. . For example, when the refrigerant temperature is high, the cooling temperature of the refrigerant is decreased, and when the refrigerant temperature is low, the cooling temperature of the refrigerant is adjusted to be high. That is, the control means (240) determines the load state of the refrigeration system (10) based on the refrigerant temperature.
• a fourteenth solution is the supercooling refrigerant according to the first solution, wherein the cooling fluid circuit circulates a supercooling refrigerant as a cooling fluid to perform a vapor compression refrigeration cycle.
• the surrounding condition of the supercooling heat exchanger (210) is the low pressure or the high pressure of the supercooling refrigerant in the supercooling refrigerant circuit (220).
• the cooling temperature of the refrigerant in the refrigerant passage (205) in the subcooling heat exchanger (210) is set at the actual low pressure or the actual low pressure of the subcooling refrigerant in the subcooling refrigerant circuit (220). Adjusted based on high pressure.
• the low pressure of the supercooling refrigerant is regarded as the suction pressure of the compressor of the supercooling refrigerant circuit (220), and the high pressure of the supercooling refrigerant is regarded as the discharge pressure of the compressor of the supercooling refrigerant circuit (220). Considered as pressure.
• the control means (240) determines the load state of the refrigeration apparatus (10) based on the low pressure or the high pressure in the vapor compression refrigeration cycle of the subcooling refrigerant circuit (220).
• a fifteenth solution is the first solution, wherein the cooling fluid circuit is a supercooling refrigerant in which a supercooling refrigerant as a cooling fluid circulates to perform a vapor compression refrigeration cycle.
• the ambient condition of the subcooling heat exchanger (210) is the temperature of the subcooling refrigerant after the refrigerant in the refrigerant passage (205) is cooled by the subcooling heat exchanger (210).
• the cooling temperature of the refrigerant in the refrigerant passage (205) in the subcooling heat exchanger (210) is adjusted based on the actual temperature of the subcooling refrigerant after cooling.
• the temperature of the subcooling refrigerant may be regarded as the suction temperature of the compressor of the subcooling refrigerant circuit (220). For example, when the temperature of the subcooling refrigerant is high, the cooling temperature of the refrigerant is lowered, and when the temperature of the supercooling refrigerant is low, the cooling temperature of the refrigerant is adjusted to be high. That is, the control means (240) determines the load state of the refrigeration system (10) based on the temperature of the subcooling refrigerant after cooling in the subcooling refrigerant circuit (220).
• the cooling temperature of the refrigerant in the refrigerant passage (205) is adjusted based on the ambient conditions of the subcooling heat exchanger (210) which can be detected in the device. Therefore, even if signals are not exchanged between the heat source unit (11) and the utilization unit (12, 13, 14), an appropriate signal can be taken according to the load state of the utilization unit (12, 13, 14). Driving can be performed. Therefore, when attaching the subcooling device to the refrigeration unit (10), simply connect the refrigerant passage (205) of the subcooling unit to the connection pipe of the refrigeration unit (10). There is no need to lay communication wiring for exchanging signals between devices. As a result, it is possible to reduce the number of man-hours required for attaching the subcooling device to the refrigeration system (10), and further to prevent troubles caused by human error during installation work such as incorrect wiring.
• the constant is determined according to the ambient conditions of the subcooling heat exchanger (210). Based on the target cooling temperature of the refrigerant in the refrigeration system (10) in the subcooling heat exchanger (210), the flow rate of the cooling fluid flowing through the subcooling heat exchanger (210) is adjusted. Therefore, it is also possible to perform more appropriate adjustment of the cooling capacity using only the information obtained in the subcooling device.
• the cooling fluid circuit is constituted by the subcooling refrigerant circuit (220), and the supercooling compressor (221) or the heat source side heat exchanger (222) ),
• the flow rate of the supercooling refrigerant in the supercooling heat exchanger (210) is adjusted by controlling the operation of the fan (230), so that the cooling temperature of the refrigerant in the refrigeration system (10) is surely adjusted.
• the ninth solution based on the difference between the set temperature determined by the saturation temperature corresponding to the low-pressure pressure of the supercooling refrigerant and the target cooling temperature, and according to the seventh or the tenth solution, Based on the difference between the set temperature determined from the suction temperature of the subcooling compressor (221) and the target cooling temperature, the operation of the supercooling compressor (221) and fan (230) is controlled. Therefore, in this case as well, it is possible to adjust the cooling capacity more suitable for the load condition using only the information obtained in the subcooling device.
• the ambient conditions of the supercooling heat exchange (210) include the outside air temperature or the state quantity of the refrigerant on the refrigeration apparatus (10) side.
• the flow rate and temperature of the refrigerant, or the pressure and temperature of the refrigerant, which is the state quantity of the refrigerant in the subcooling refrigerant circuit (220) are used. Since the temperature is regarded as the detected temperature, it can be reliably and easily obtained as information obtained in the subcooling device. As a result, a highly reliable device can be provided.
• 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 of the refrigeration system during a cooling operation.
• FIG. 3 is a piping diagram showing an operation of the refrigeration system during a first heating operation.
• FIG. 4 is a piping diagram illustrating an operation of the refrigeration system during a first heating operation.
• FIG. 5 is a piping diagram showing an operation of the refrigeration system during a second heating operation.
• FIG. 6 is a flowchart showing a control operation of a controller in the supercooling unit.
• FIG. 7 is a graph showing a relationship between an outside air temperature and a target cooling temperature.
• the refrigeration system of this embodiment is installed in a convenience store or the like, and performs air conditioning in the store and cooling in the showcase.
• the 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.
• 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 system (10).
• an outdoor unit (11) and a subcooling unit (200) are installed outdoors, and the remaining air conditioning unit (12) is installed in a store such as a convenience store.
• the outdoor unit (11) has an outdoor circuit (40) power
• the air conditioning unit (12) has an air conditioning circuit (100) power
• the refrigeration showcase (13) has a refrigeration circuit (110) power 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).
• a refrigerant circuit (20) is formed by connecting the above-described circuits (40, 100,...) And the refrigerant passage (205) of the supercooling unit (200) with piping.
• 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 side communication pipe (24) is provided.
• 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 connection pipe (22) is branched into three and air-conditioned.
• a branch pipe connected to the refrigeration circuit (130) of the second liquid side communication pipe (22) is provided with a liquid side shutoff valve (25).
• One end of the first gas side communication pipe (23) is branched into two and connected to a refrigeration circuit (110) and a booster circuit (140).
• a branch pipe connected to the booster circuit (140) of the first gas-side communication pipe (23) is provided with a gas-side shut-off valve (26).
• the other end of the first gas side communication pipe (23) is connected to an outdoor circuit (40).
• the second gas side communication pipe (24) connects the air conditioning circuit (100) to the outdoor circuit (40).
• the outdoor unit (11) constitutes a heat source unit of the refrigeration system (10).
• the outdoor circuit (40) of the outdoor unit (11) includes a variable capacity compressor (41), a first fixed capacity compressor (42), a second fixed capacity compressor (43), and an outdoor heat exchanger.
• a vessel (44), a receiver (45), and an outdoor expansion valve (46) are provided.
• the outdoor circuit (40) has three suction pipes (61, 62, 63), two discharge pipes (64, 65), four liquid pipes (81, 82, 83, 84), One high pressure gas pipe (66) is provided.
• the outdoor circuit (40) includes three four-way switching valves (51, 52, 53), one liquid-side shutoff valve (54), and two gas-side shutoff valves (55, 56). Is provided.
• the liquid side shutoff valve (54) has a first liquid side communication pipe (21), and the first gas side shutoff valve (55) has a first gas side communication pipe.
• the pipe (23) is connected to the second gas side shut-off valve (56) and the second gas side communication pipe (24), respectively.
• variable capacity compressor (41), the first fixed capacity compressor (42), and the second fixed capacity 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 displacement compressor (41) is variable by changing the output frequency of the inverter to change the rotation speed of the compressor motor.
• the compressor motor is always operated at a constant rotation speed, and the capacity thereof cannot be changed.
• 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),
• the first branch pipe (61a) is connected to the suction side of the variable capacity compressor (41), and the second branch pipe (61b) is connected to the third four-way switching valve (53).
• the second branch pipe (61b) of the first suction pipe (61) has a check valve that allows only the flow of refrigerant from the first gas side shut-off valve (55) to the third four-way switching valve (53).
• a valve (CV-1) is provided.
• the second suction pipe (62) has one end connected to the third four-way switching valve (53) and the other end connected to the suction side of the first fixed displacement compressor (42)! RU
• 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 the second fixed capacity compressor.
• the second branch pipe (63b) is connected to the third four-way switching valve (53) on the suction side of (43).
• the second branch pipe (63b) of the third suction pipe (63) has a check that allows only the flow of refrigerant 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).
• a second branch pipe (64b) is connected to the discharge side of the first fixed displacement compressor (42) on the discharge side of the compressor (41).
• the other end of the first discharge pipe (64) is connected to a first four-way switching valve (51).
• the second branch pipe (64b) of the first discharge pipe (64) has a check valve that allows only refrigerant flow from the first fixed displacement compressor (42) to the first four-way switching valve (51).
• a valve (CV-3) is provided.
• the second discharge pipe (65) has one end connected to the suction side of the second fixed displacement compressor (43) and the other end connected to the first four-way switching valve (51) in the first discharge pipe (64). Each is connected immediately before.
• the second discharge pipe (65) has a check valve (CV-4) that allows only the flow of refrigerant to the first four-way switching valve (51) from the second fixed displacement compressor (43) to the first four-way switching valve (51). Is provided.
• the outdoor heat exchanger (44) is a cross-fin type fin-and-tube heat exchanger.
• heat is exchanged between the refrigerant and the outdoor air.
• One end of the outdoor heat exchange (44) is connected to a first four-way switching valve (51) via a closing valve (57).
• the other end of the outdoor heat exchange (44) is connected to the top of a receiver (45) via a 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 exchange (44) to the receiver (45).
• One end of a second liquid pipe (82) is connected to the bottom of the receiver (45) via a closing valve (58).
• the other end of the second liquid pipe (82) is connected to the liquid-side stop valve (54).
• the second liquid pipe (82) is provided with a check valve (CV-6) that allows only the flow of the refrigerant flowing from the receiver (45) to the liquid-side stop valve (54). .
• a third liquid pipe is provided between the check valve (CV-6) and the liquid-side stop valve (54) in the second liquid pipe (82).
• One end of (83) is connected.
• the other end of the third liquid pipe (83) is connected to the top of the receiver (45) via the first liquid pipe (81).
• the third liquid pipe (83) is provided with a check valve (CV-7) that allows only the flow of the refrigerant flowing from one end to the other end.
• a fourth liquid pipe (84) is connected between the closing valve (58) and the check valve (CV-6) in the second liquid pipe (82).
• the other end of the fourth liquid pipe (84) is connected between the outdoor heat exchange (44) and the check valve (CV-5) in the first liquid pipe (81).
• the fourth liquid pipe (84) is provided with a check valve (CV-8) and an outdoor expansion valve (46) in order of one end force and the other end.
• This check valve (CV-8) allows only one direction force of the fourth liquid pipe (84) to flow to the other end of the fourth liquid pipe (84).
• the outdoor expansion valve (46) is constituted by an electronic expansion valve.
• 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).
• the first branch pipe (66a) of the high-pressure gas pipe (66) is provided with a solenoid valve (SV-7) and a check valve (CV-9). This check valve (CV-9) is located downstream of the solenoid valve (SV-7), and allows only refrigerant flowing from the solenoid valve (SV-7) to the first liquid pipe (81). I do.
• 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.
• the fourth port is connected to the outdoor heat exchange (44), and the fourth port is connected to the second gas side shutoff 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 (shown by a solid line in FIG. 1). 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.
• the second four-way switching valve (52) has a first port downstream of the check valve (CV-4) in the second discharge pipe (65), and a second port connected to the second suction pipe. At the beginning of (62), the fourth ports are connected to the second ports of the first four-way switching valve (51), respectively.
• 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 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). ing.
• 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 second suction pipe (62). At the beginning of the third port, 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 to the end.
• 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 solid line in FIG. 1). 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.
• the outdoor circuit (40) is further provided with an injection pipe (85), a communication pipe (87), an oil separator (75), and an oil return pipe (76).
• the outdoor circuit (40) is also provided with four oil equalizing pipes (71, 72, 73, 74).
• the injection pipe (85) is for performing so-called liquid injection.
• One end of the injection pipe (85) is provided between the check valve (CV-8) and the outdoor expansion valve (46) in the fourth liquid pipe (84), and the other end is provided in 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 of one end force and the other end.
• the flow control valve (86) is formed by an electronic expansion valve.
• the communication pipe (87) is provided between the closing valve (59) and the flow rate regulating valve (86) in the one-sided force injection pipe (85), and the other end is a first branch of the high-pressure gas pipe (66). They are connected to the pipe (66a) on the upstream side of the solenoid valve (SV-7), respectively.
• the communication pipe (87) is provided with a check valve (CV-10) that allows only the flow of the refrigerant from one end to the other end.
• the oil separator (75) is provided upstream of the connection position of the second discharge pipe (65) and the high-pressure gas pipe (66) in the first discharge pipe (64). The oil separator (75) is also for separating the refrigerating machine oil from the discharge gas power of the compressor (41, 42).
• 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), and the first branch pipe (76a) is connected to the injection pipe (85). Downstream of the flow control valve (86), second branch pipes (76b) are connected to the second suction pipes (62), respectively.
• 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).
• the first oil equalizing pipe (71) has one end connected to the variable capacity compressor (41) and the other end connected to the second suction pipe (62).
• the first oil equalizing pipe (71) is provided with a solenoid valve (SV-1).
• 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 level pipe (72) is provided with a solenoid valve (SV-2).
• the third oil equalizing pipe (73) has one end connected to the second fixed displacement compressor (43) and the other end connected to the first branch pipe (61a) of the first suction pipe (61)! You.
• the third oil level pipe (73) is provided with a solenoid valve (SV-3).
• the fourth oil leveling pipe (74) has one end connected to the second oil leveling pipe (72) upstream of the solenoid valve (SV-2), and the other end connected to the first branch pipe (61) of the first suction pipe (61). 61a).
• the fourth oil level pipe (74) is provided with a solenoid valve (SV-4).
• the outdoor circuit (40) is provided with various sensors and pressure switches.
• 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) has a first discharge temperature sensor (97) and a first discharge An output pressure sensor (98) is provided.
• Each of the branch pipes (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).
• 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 an outdoor fan (48).
• the air conditioning unit (12) constitutes a use unit.
• the air conditioning circuit (100) of the air conditioning unit (12) has a liquid side end connected to the second liquid side connection pipe (22) and a gas side end connected to the second gas side connection pipe (24).
• an air conditioning expansion valve (102) and an air conditioning heat exchange (101) are provided in order with the liquid side end force also directed toward the gas side end.
• This air conditioning heat exchange (101) is a cross-fin type fin 'and' tube type heat exchange ⁇ .
• heat is exchanged between the refrigerant and room air.
• the air conditioning expansion valve (102) is constituted by an electronic expansion valve.
• the air conditioning unit (12) is provided with a heat exchange 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 attached 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 indoor air in the store is sent to the air conditioning heat exchange (101) by the air conditioning fan (105).
• the refrigerated showcase (13) constitutes a use unit.
• the refrigeration circuit (110) of the refrigerated showcase (13) has a liquid side end connected to the second liquid side communication pipe (22) and a gas side end connected to the first gas side communication pipe (23). .
• a refrigeration solenoid valve (114), a refrigeration expansion valve (112), and a refrigeration heat exchange (111) are provided in this order with the liquid side end force also directed to the gas side end. ! / Puru.
• This refrigerated heat exchange (111) is a cross-fin type fin 'and' tube type heat exchanger. This refrigerated heat exchange In the vessel (111), heat exchange is performed between the refrigerant and the air in the refrigerator.
• the refrigeration expansion valve (112) is constituted by an automatic temperature expansion valve.
• the temperature sensing tube (113) of the refrigeration expansion valve (112) is attached to a pipe on the outlet side of the refrigeration heat exchanger (111).
• the refrigerated showcase (13) is provided with a refrigerator temperature sensor (116) and a refrigerator fan (115).
• the air in the refrigerator showcase (13) is sent to the refrigerator heat exchange (111) by the fan (115) in the refrigerator.
• the frozen showcase (14) constitutes a use unit.
• the refrigeration circuit (130) of the refrigeration showcase (14) 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 a booster unit (15) via a pipe.
• a refrigeration solenoid valve (134), a refrigeration expansion valve (132), and a refrigeration heat exchange (131) are provided in this order with the liquid side end force also directed to the gas side end.
• This frozen heat exchange (131) is a cross-fin type fin 'and' tube type heat exchanger.
• 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).
• the freezer showcase (14) is provided with a freezer temperature sensor (136) and a freezer fan (135). Air in the freezer showcase (14) is sent to the freezing heat exchanger (131) by the freezer fan (135).
• the booster circuit (140) of the booster unit (15) includes a booster compressor (141), an intake pipe (143), a discharge pipe (144), and a bypass pipe (150).
• the booster compressor (141) is a hermetic, high-pressure dome-type scroll compressor.
• the booster compressor (141) is supplied with electric power via an inverter.
• the capacity of this booster compressor (141) can be changed by changing the output frequency of the inverter to change the rotation speed of the compressor motor.
• the end of the suction pipe (143) is connected to the suction side of the booster compressor (141). This The start end of the suction pipe (143) is connected to the gas side end of the refrigeration circuit (130) via a pipe.
• the discharge pipe (144) has a start end connected to the discharge side of the booster compressor (141), and an 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-side check valve (149) in order from the start end to the end.
• the discharge-side check valve (149) allows only the refrigerant to flow toward the end of the discharge pipe (144).
• the oil separator (145) is for separating the refrigerating machine oil discharged from 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 a 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 returned to the suction side of the booster compressor (141) through the oil return pipe (146).
• the bypass pipe (150) is connected at the beginning to the suction pipe (143) and at the end between the oil separator (145) and the discharge-side check valve (149) in the discharge pipe (64). ing.
• the bypass pipe (150) is provided with a bypass check valve (151) that allows only the flow of the refrigerant toward the terminal end.
• the subcooling unit (200) includes a refrigerant passage (205), a subcooling refrigerant circuit (220), and a controller (240).
• the refrigerant passage (205) has one end connected to the first liquid side communication pipe (21) and the other end connected to the second liquid side communication pipe (22).
• the subcooling refrigerant circuit (220) includes a subcooling compressor (221), a subcooling outdoor heat exchanger (222), a subcooling expansion valve (223), and a supercooling heat. This is a closed circuit configured by connecting the exchanger (210) in sequence with piping.
• the supercooling refrigerant circuit (220) constitutes a cooling fluid circuit for performing a vapor compression refrigeration cycle by circulating a supercooling refrigerant as a filled cooling fluid.
• the supercooling compressor (221) is a hermetically sealed high-pressure dome type scroll compressor.
• the Electric power is supplied to the subcooling compressor (221) via an inverter.
• the capacity of the supercooling compressor (221) is variable 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 heat exchanger, and constitutes a heat source side heat exchanger.
• the supercooling expansion valve (223) is constituted by an electronic expansion valve.
• the supercooling heat exchanger (210) is a so-called plate heat exchanger, and constitutes use-side heat exchange.
• a plurality of first flow paths (211) and a plurality of second flow paths (212) are formed.
• 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). .
• the supercooling unit (200) is 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 A discharge temperature sensor (233) and a high pressure switch (232) are provided on the discharge side of the compressor (221). In the refrigerant passage (205), a refrigerant temperature sensor (236) is provided at a part closer to the other end than the supercooling heat exchanger (210), that is, a part near the end connected to the second liquid side communication pipe (22). It is provided. This refrigerant temperature sensor (236) constitutes a refrigerant temperature detecting means.
• 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 an outdoor fan (230).
• the controller (240) constitutes control means.
• the controller (240) includes a setting unit (241) and a control unit (242).
• the outside temperature which is the temperature detected by the outside temperature sensor (231), is input to the setting unit (241). Then, the setting unit (241) determines a target cooling temperature (Eom) of the refrigerant in the refrigerant passage (205) in the subcooling heat exchanger (210) which is set in advance based on the input outside air temperature. ) Is set. For example, when the outside air temperature is high, the cooling load in the store increases, so the target cooling temperature (Eom) of the refrigerant is set to a low temperature. Conversely, when the outside air temperature is low, the cooling load in the store becomes small, so the target cooling temperature (Eom) of the refrigerant is set to a higher temperature. That is, in the setting unit (241) of the present embodiment, the outside air temperature is used as the ambient condition of the supercooling heat exchange (210).
• the detected temperature (Tout) of the refrigerant temperature sensor (236) and the detected pressure (LP) of the suction pressure sensor (234) are input to the control unit (242).
• the control unit (242) detects the detected temperature (T out) of the refrigerant temperature sensor (236) and the target cooling temperature (Tout) of the setting unit (241).
• the operating frequency of the subcooling compressor (221) is controlled based on the difference from Eom).
• the control unit (242) controls the supercooling refrigerant corresponding to the detected pressure (LP) of the suction pressure sensor (234).
• the operation frequency of the supercooling compressor (221) is controlled based on the difference between the set temperature (Tout) determined by the saturation temperature (TG) and the target cooling temperature (Eom).
• the control unit (242) detects the set temperature (Tout) determined by the low pressure equivalent saturation temperature (TG) of the subcooling refrigerant in the subcooling refrigerant circuit (220) by the refrigerant temperature sensor (236).
• the set temperature (Tout) is set at the saturation temperature (TG) + a ° C. This a can be set arbitrarily.
• the control unit (242) regards the set temperature determined by the detected pressure (LP) of the suction pressure sensor (234) as the detected temperature (Tout) of the refrigerant.
• the set temperature (Tout) determined by the suction temperature (Ti) detected by the suction temperature sensor (235) may be regarded as the detected temperature (Tout) of the refrigerant.
• the detected temperature (Tout) of the refrigerant temperature sensor (236) and the detected temperature ( ⁇ ) of the suction temperature sensor (235) are input to the control unit (242).
• the control unit (242) sets the target temperature (Tout) and the set temperature (Tout) determined by the detected temperature (Ti) of the suction temperature sensor (235).
• the operating frequency of the subcooling compressor (221) is controlled based on the difference from the temperature (Eom).
• the set temperature (Tout) is set, for example, at the detection temperature (Ti) + ⁇ ° C. This 13 can be set arbitrarily.
• the circulation amount of the supercooling refrigerant in the subcooling refrigerant circuit (220) is increased, and the subcooling heat exchanger (210) Since the amount of heat exchange between the supercooling refrigerant and the refrigerant of the refrigeration unit (10) in () increases, the cooling temperature of the refrigerant of the refrigeration unit (10) decreases, and the cooling capacity of the air conditioning unit (12) increases. Will be.
• the controller (240) adjusts the flow rate of the subcooling refrigerant in the subcooling heat exchanger (210) by controlling the capacity of the subcooling compressor (221) based on the outside air temperature. Adjust the cooling temperature of the refrigerant in the refrigeration system (10)!
• the target cooling temperature (Eom) of the refrigerant is set based on the outside air temperature as the ambient condition of the supercooling heat exchanger (210).
• the following (parameter) may be used instead of the outside air temperature.
• the setting unit (241) determines the flow rate of the refrigerant in the refrigerant passage (205), that is, the flow rate of the refrigerant in the refrigerating device (10) in the subcooling heat exchanger (210) by using the subcooling heat exchanger ( It may be used as the surrounding condition of 210).
• means for detecting the flow rate of the refrigerant is provided upstream of the subcooling heat exchanger (210) in the refrigerant passage (205), and the detected flow rate of the flow rate detecting means is transmitted to the setting section (241) of the controller (240). Is entered.
• the setting unit (241) determines that the cooling load in the store is large, sets the target cooling temperature (Eom) of the refrigerant to a low temperature, and conversely, detects If the flow rate is low, determine that the cooling load in the store is small, and set the target cooling temperature (Eom) of the refrigerant to a higher temperature. To do.
• the setting section (241) is configured to control the temperature of the refrigerant in the refrigerant passage (205) before being cooled by the subcooling heat exchanger (210), or to cool the refrigerant by the subcooling heat exchanger (210).
• the temperature of the refrigerant in the refrigerant passage (205) after the cooling may be used as the surrounding condition of the supercooling heat exchange (210).
• a refrigerant temperature detecting means is provided upstream of the subcooling heat exchanger (210) in the refrigerant passage (205), and the controller (240) detects the refrigerant temperature before the detected temperature of the flow rate detecting means is cooled. ) Is input to the setting unit (241).
• the temperature detected by the refrigerant temperature sensor (236) provided downstream of the subcooling heat exchanger (210) is input to the setting unit (241) of the controller (240). Then, when the input detected temperature is high, the setting unit (241) determines that the cooling load in the store is large, and sets the target cooling temperature (Eom) of the refrigerant to low and temperature, and conversely. If the detected temperature is low, it is determined that the cooling load in the store is small, and the target cooling temperature (Eom) of the refrigerant is set to a higher temperature.
• the setting unit (241) uses the low pressure or the high pressure of the subcooling refrigerant in the subcooling refrigerant circuit (220) as ambient conditions for the supercooling heat exchange (210). Is also good.
• the detection pressure of the suction pressure sensor (234) provided on the suction side of the subcooling compressor (221) is input to the setting unit (241) as a low pressure.
• refrigerant pressure detecting means is provided on the discharge side of the supercooling compressor (221), and the detected pressure of the pressure detecting means is input to the setting section (241) as a high pressure.
• the setting unit (241) determines that the cooling load in the store is large, sets the target cooling temperature (Eom) of the refrigerant to a low temperature, and conversely, detects If the pressure is low, it is determined that the cooling load in the store is small, and the target cooling temperature (Eom) of the refrigerant is set to a higher temperature.
• the setting unit (241) may use the temperature of the subcooling refrigerant after cooling in the subcooling heat exchanger (210) as the ambient condition of the subcooling heat exchanger (210).
• the temperature detected by the suction temperature sensor (235) of the subcooling compressor (221) is input to the setting unit (241).
• a refrigerant temperature detecting means is provided immediately downstream of the subcooling heat exchanger (210) in the subcooling refrigerant circuit (220), and the temperature detected by the temperature detecting means is the above-mentioned suction temperature sensor (235). Is input to the setting unit (241) in place of the detected temperature.
• the setting unit (241) determines that the in-store cooling load is large, and sets the target cooling temperature (Eom) of the refrigerant to a low temperature. In the case of a low V, the cooling load in the store is judged to be small, and the target cooling temperature (Eom) of the refrigerant is set to a higher temperature.
• the cooling operation is an operation 5 for cooling the inside of the store by cooling the indoor air in the refrigerated showcase (13) and the freezing showcase (14), and cooling the indoor air in the air conditioning unit (12).
• the first four-way switching valve (51), the second four-way switching valve (52) and the third four-way switching valve (53) are respectively the first four-way switching valve (51).
• 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.
• the variable capacity compressor (41), the first fixed capacity compressor (42), the second fixed capacity compressor (43), and the booster compressor (141) are operated.
• the subcooling unit (200) is in an operating state. The operation of the subcooling unit (200) will be described later.
• the refrigerant discharged from the variable displacement compressor (41), the first fixed displacement compressor (42) and the second fixed displacement compressor (43) passes through the first four-way switching valve (51). Sent to outdoor heat exchange (44). In this outdoor heat exchange (44), the refrigerant radiates heat to outdoor air and condenses.
• the refrigerant condensed in the outdoor heat exchange (44) passes through the first liquid pipe (81), the receiver (45), and the second liquid pipe (82) in that order, and goes to the first liquid side communication pipe (21). Inflow.
• 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 path (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 is refrigerated with the air conditioning circuit (100). It is distributed to a circuit (110) and a refrigeration circuit (130).
• the refrigerant that has flowed into the air conditioning circuit (100) is depressurized when passing through the air conditioning expansion valve (102), and the refrigerant is also introduced into the air conditioning heat exchange (101).
• the air conditioning heat exchange (101) the refrigerant absorbs heat from room air and evaporates.
• the evaporation temperature of the refrigerant is set to, for example, about 5 ° C.
• the room air cooled by the air conditioning heat exchange (101) is supplied into the store.
• the refrigerant evaporated in the air-conditioning heat exchanger (101) flows into the outdoor circuit (40) through the second gas side communication pipe (24), and then flows into the first four-way switching valve (51). And the second four-way switching valve (52), and flows into the third suction pipe (63). 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 remainder flows into the second branch pipe (63b). And the third four-way switching valve (53) and the second suction pipe (62), and are sucked into the first fixed displacement compressor (42).
• 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 cold refrigeration heat exchanger m ⁇ (iii).
• the refrigerant absorbs heat from the air in the refrigerator and evaporates.
• 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).
• the air in the refrigerator cooled by refrigeration heat exchange (ll) is supplied into the refrigerator, and the temperature in the refrigerator is maintained at, for example, about 5 ° C.
• the refrigerant that has flowed into the refrigeration circuit (130) is decompressed when passing through the refrigeration expansion valve (132), and the refrigerant is also introduced into the refrigeration heat exchanger (131).
• the refrigerant absorbs heat from the air in the refrigerator and evaporates.
• the evaporation temperature of the refrigerant is set to, for example, about 30 ° C.
• the freezer showcase (14) the air in the refrigerator cooled by the freezing heat exchange (131) is supplied into the refrigerator, and the temperature in the refrigerator is maintained at, for example, about 20 ° C.
• the refrigerant flowing into the first suction pipe (61) is sucked into the variable displacement compressor (41) through the first branch pipe (61a).
• 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 inside air is heated by the air conditioning unit (12) to heat the inside of the store. .
• the first four-way switching valve (51) is in the second state
• the second four-way switching valve (52) is in the first state
• the third four-way switching valve (52) is in the third state.
• the path switching valves (53) are set to the first state, respectively.
• the outdoor expansion valve (46) is fully closed, the openings of the air conditioning expansion valve (102), the refrigeration expansion valve (112), and the refrigeration expansion valve (132) are appropriately adjusted.
• 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.
• the outdoor heat exchanger (44) enters a rest state without being supplied with the refrigerant.
• the subcooling unit (200) is in a stopped state.
• variable capacity compressor (41) force The discharged refrigerant passes through the first four-way switching valve (51) and the second gas side communication pipe (24) in order, and exchanges air conditioning heat of the air conditioning circuit (100). It is introduced into the vessel (101) and releases heat to the indoor air to condense. In the air conditioning unit (12), the indoor air heated by heat in 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).
• 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).
• 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).
• the refrigerant flowing into the first gas side communication pipe (23) passes through the first suction pipe (61), and then passes through the variable capacity compressor (41). It is inhaled and compressed.
• 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 inside of the store is heated by utilizing the heat of the refrigerant absorbing the internal air power in the refrigerator heat exchanger (111) and the freezing heat exchanger (131).
• the first fixed displacement compressor (42) may be operated. Whether or not to operate the first fixed displacement 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). It 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.
• 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 first heating operation has insufficient heating capacity.
• the first four-way switching valve (51) is in the second state
• the second four-way switching valve (52) is in the first state
• the third four-way switching valve (52) is in the third state.
• the path switching valves (53) are set to the first state, respectively.
• 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.
• 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.
• the subcooling unit (200) is in a stopped state.
• the refrigerant discharged from the variable displacement compressor (41) and the second fixed displacement compressor (43) passes through the first four-way switching valve and the second gas side communication pipe (24) in order. It is introduced into the air conditioning heat exchange (101) of the air conditioning circuit (100), and releases heat to indoor air to condense. In the air conditioning unit (12), the room air heated by the air conditioning heat exchange (101) is supplied into the store. The refrigerant condensed in the air conditioning heat exchange (101) flows into the second liquid side communication pipe (22). 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). Then, the remainder is introduced into the refrigerant passage (205) of the subcooling unit (200).
• 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).
• 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).
• the refrigerant that has flowed into the first gas side communication pipe (23) passes through the first suction pipe (61), is drawn into the variable displacement compressor (41), and is compressed.
• the refrigerant that has flowed into the refrigerant passage (205) of the subcooling unit (200) is connected to the first liquid side communication pipe.
• the liquid (21) passes through the third liquid pipe (83) in order, flows into the receiver (45), and then flows into the fourth liquid pipe (84) through the second liquid pipe (82).
• the refrigerant flowing into the fourth liquid pipe (84) is decompressed when passing through the outdoor expansion valve (46), is introduced into the outdoor heat exchange (44), and absorbs heat from outdoor air to evaporate. .
• the refrigerant evaporated in the outdoor heat exchanger (44) sequentially passes through the first four-way switching valve (51) and the second four-way switching valve (52) and flows into the second suction pipe (62). Is sucked into the second fixed capacity compressor (43) and compressed.
• the refrigerant absorbs heat in the refrigeration heat exchanger (111), the refrigeration heat exchanger (131), and the outdoor heat exchanger (44), and the refrigerant absorbs heat in the air conditioning heat exchanger (101).
• the refrigerant releases heat.
• 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) are used. Then, the inside of the store is heated.
• the operation of the supercooling unit (200) will be described.
• the supercooling compressor (221) is operated, and the opening of the supercooling expansion valve (223) is appropriately adjusted.
• the supercooling refrigerant discharged from the supercooling compressor (221) radiates heat to outdoor air in the supercooling outdoor heat exchanger (222) and condenses.
• the subcooling refrigerant condensed in the subcooling outdoor heat exchanger (222) is decompressed when passing through the subcooling expansion valve (223), and then is discharged to the first subcooling heat exchanger (210). Flow into the channel (211).
• This supercooling heat exchange In the first flow path (211) of (210) the supercooling refrigerant evaporates by absorbing the refrigerant power of the second flow path (212).
• the subcooling refrigerant evaporated in the subcooling heat exchanger (210) is drawn into the subcooling compressor (221) and compressed.
• the controller (240) controls the capacity of the subcooling compressor (221) based on the input outside air temperature.
• 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 intervals of 30 seconds).
• the detected temperature (Tout) force of the refrigerant temperature sensor (236) also subtracts the target cooling temperature (Eom) set by the setting unit (241) of the controller (240). Is calculated.
• the target cooling temperature (Eom) is set. Specifically, the target cooling temperature (Eom) is set to 25 ° C if the outside air temperature is relatively low at 25 ° C or less, and the target cooling temperature (Eom) if the outside air temperature is high at 40 ° C or more. Is set to 0 ° C.
• the target cooling temperature (Eom) is set so as to decrease proportionally to 25 ° C and 0 ° C.
• the set value of the target cooling temperature (Eom) is not limited to this value! /.
• step ST1 if the difference between the detected temperature (Tout) and the target cooling temperature (Eom) is "less than 11.0", the process proceeds to step ST2, and the process proceeds to "more than +1.0". If there is, the process proceeds to step ST3, and if it is “ ⁇ 1.0 to +1.0”, the process returns and the control ends. That is, if the cooling capacity of the refrigeration system (10) is excessively cooled and the cooling capacity is excessive, the process proceeds to step ST2, and the cooling capacity of the refrigeration system (10) is insufficient due to insufficient cooling of the cooling medium. If is not enough, move to step ST3.
• the range of “ ⁇ 1.0 to +1.0” is a non-change range where the operating frequency of the supercooling compressor (221) is not changed.
• the setting range is, for example, “ ⁇ 1.5 to +1.5 ”and“ ⁇ 2.0 to +2.0 ”. In that case, the set values of “less than ⁇ 1.0” and “more than +1.0” are also switched accordingly.
• step ST2 it is determined whether or not the operation frequency of the subcooling compressor (221) is the lowest frequency. If it is determined that the operation frequency is the lowest frequency, the process returns and the control is terminated. Then, the process proceeds to step ST4.
• the operating frequency of the subcooling compressor (221) is reduced by one step by the control unit (242) of the controller (240). The As a result, the cooling temperature of the refrigerant in the refrigeration system (10) increases, so that the cooling capacity or the like that has been in an excessive state can be reduced to an appropriate capacity according to the load.
• step ST3 it is determined whether or not the operating frequency of the subcooling compressor (221) is the highest frequency. If it is determined that the operating frequency is the highest frequency, the process returns and the control is terminated, and it is determined that the frequency is not the highest frequency. Then, the process proceeds to step ST5.
• step ST5 the operating frequency of the subcooling compressor (221) is increased by one step by the control unit (242) of the controller (240). As a result, the cooling temperature of the refrigerant in the refrigeration system (10) decreases, so that the cooling capacity or the like that has been in an insufficient state can be increased to an appropriate capacity according to the load.
• the operating frequency of the supercooling compressor (221) can be changed in 20 steps.
• Step ST1 the set temperature determined using the detected pressure of the suction pressure sensor (234) is determined. (Tout) minus the target cooling temperature (Eom) of the setting part (241) is calculated.
• the subsequent control is the same as the control described above.
• the operation of the supercooling compressor (221) was controlled to adjust the cooling temperature of the refrigerant in the refrigeration system (10).
• the air conditioner unit (12) can be operated properly according to the load condition of the air conditioning unit (12) without sending / receiving signals to / from the refrigeration system (10). . Therefore, when attaching the subcooling unit (200) to the refrigeration system (10), the refrigerant of the subcooling unit (200) is connected to the first and second liquid side communication pipes (21, 22) of the refrigeration system (10). By simply connecting the passage (205), there is no need to lay communication wiring for transmitting and receiving signals between the refrigeration system (10) and the supercooling unit (200).
• the controller (240) determines the detected temperature (Tout) of the refrigerant and the outside air temperature. Based on the difference from the target cooling temperature (Eom), the operation of the subcooling compressor (221) is controlled, so that this is also ensured only by the information obtained in the subcooling unit (200).
• the cooling capacity can be adjusted in a short time.
• 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. You don't have to. Therefore, the usability of the supercooling unit (200) can be greatly improved.
• the operating frequency of the outdoor fan (230) of the subcooling outdoor heat exchanger (2 22) is controlled to The flow rate of the subcooling refrigerant in the vessel (210) is adjusted. That is, the capacity of the outdoor fan (230) of the present modified example is variable by changing the operating frequency of the fan motor.
• the high pressure in the subcooling refrigerant circuit (220) decreases, and the circulation amount of the supercooling refrigerant decreases. That is, the flow rate of the subcooling refrigerant in the subcooling heat exchanger (210) decreases.
• the amount of heat exchange between the supercooling refrigerant in the supercooling heat exchanger (210) and the refrigerant in the refrigeration system (10) decreases, and the cooling temperature of the refrigerant in the refrigeration system (10) increases, The cooling capacity and the like of the air conditioning unit (12) will be reduced.
• step ST2 of FIG. 6 it is determined whether or not the operating frequency of the outdoor fan (230) is the highest frequency. If it is determined that the operating frequency is the highest frequency, the process returns and the control is terminated. Then, the process proceeds to step ST4.
• step ST4 the operating frequency of the outdoor fan (230) is increased by one step by the control unit (242) of the controller (240). As a result, the cooling temperature of the refrigerant in the refrigeration system (10) rises, so that the cooling capacity or the like that was in an excessive state can be reduced to an appropriate capacity according to the load.
• step ST3 it is determined whether or not the operation frequency of the outdoor fan (230) is the lowest frequency power, and if it is determined that the operation frequency is the lowest frequency, the process returns and the control ends, and if it is determined that the operation frequency is not the lowest frequency. Then, the process proceeds to step ST5.
• the operating frequency of the outdoor fan (230) is reduced by one step by the control unit (242) of the controller (240).
• the cooling temperature of the refrigerant in the refrigeration system (10) decreases, so that the insufficient cooling capacity and the like can be increased to an appropriate capacity according to the load.
• Other configurations, operations and effects are the same as those of the embodiment.
• the present invention adjusts the flow rate of the subcooling refrigerant in the supercooling heat exchanger (210) by controlling both the subcooling compressor (221) and the outdoor fan (230). It may be. In this case, the controllability of the cooling temperature of the refrigerant is improved.
• Modification 2 is a modification of the configuration of the cooling fluid circuit of the above embodiment.
• the cooling fluid circuit is configured by the refrigerant circuit, but in the present modified example, the cooling fluid circuit is configured by the cooling water circuit through which the cooling water flows.
• the cooling water circuit includes a subcooling heat exchanger (210) and a pump, and the pump circulates cooling water of the cooling tower to and from the subcooling heat exchanger (210). Is composed The Then, in the supercooling heat exchanger (210), the cooling water exchanges heat with the refrigerant in the refrigerant passage (205) to cool the refrigerant. That is, in the cooling fluid circuit of the present modification, the cooling water flows as the cooling fluid.
• the operating frequency of the pump is increased to increase the flow rate of the cooling water in the supercooling heat exchange (210), thereby reducing the cooling temperature of the refrigerant.
• the cooling capacity of the air conditioning unit (12) is increased.
• the operation frequency of the pump is reduced to reduce the flow rate of the cooling water in the supercooling heat exchanger (210), thereby increasing the cooling temperature of the refrigerant and causing the air conditioning unit ( 12) Decrease the cooling capacity.
• Other configurations, operations and effects are the same as those of the embodiment.
• the setting unit (241) of the controller (240) uses, instead of the outside air temperature, the temperature of the cooling water after cooling by the supercooling heat exchanger (210). It may be used as the ambient condition of the heat exchanger (2 10)! / ,.
• the control unit (242) is configured to input the two detection values, it is also possible to input both detection values. In that case, first, when the refrigerant temperature sensor (236) is abnormal, the detected pressure (LP) of the suction pressure sensor (234) is used, and both the refrigerant temperature sensor (236) and the suction pressure sensor (234) are abnormal. In the case of, use the detected temperature ( ⁇ ) of the suction temperature sensor (235).
• the detected temperature (T out) of the refrigerant temperature sensor (236) is not input, and the detected pressure (LP) or the detected pressure (LP) of the suction pressure sensor (234) is not input. Only the detected temperature ( ⁇ ) of the suction temperature sensor (235) may be input to the control unit (242). In this case, the difference between the set temperature (Tout) determined by the detected pressure (LP) or detected temperature (Ti) and the target cooling temperature (Eom), which is related to the normal and abnormal state of the coolant temperature sensor (236), is used as a reference. As a result, the supercooling compressor (221) and the outdoor fan (230) are controlled.
• a four-way switching valve or the like is provided in the supercooling refrigerant circuit (220) of the above embodiment. If the refrigerant circulation is configured to be reversible, by connecting the refrigerant passage (205) to the gas side communication pipe of the first gas side communication pipe (23) and the second gas side communication pipe (24), the refrigeration system ( The coolant of 10) can be heated. Therefore, the so-called liquid back to each compressor (41, ") of the outdoor unit (11) can be prevented.
• the supercooling unit (200) includes the supercooling refrigerant circuit ( By configuring the refrigerant circulation of 220) to be reversible, the cooling device or the heating device of the refrigerant can be switched as required.
• the present invention is useful for a supercooling device that cools a refrigerant sent from a heat source unit of a refrigerating device to a use unit.

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Mechanical Engineering (AREA)
• Thermal Sciences (AREA)
• General Engineering & Computer Science (AREA)
• Air Conditioning Control Device (AREA)
• Compression-Type Refrigeration Machines With Reversible Cycles (AREA)

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• 2005
  • 2005-06-09 KR KR1020067005400A patent/KR100738780B1/ko not_active IP Right Cessation
  • 2005-06-09 WO PCT/JP2005/010611 patent/WO2005121655A1/ja not_active Application Discontinuation
  • 2005-06-09 CN CNB200580000683XA patent/CN100375874C/zh not_active Expired - Fee Related
  • 2005-06-09 EP EP05748824A patent/EP1679479A4/en not_active Withdrawn
  • 2005-06-09 AU AU2005252962A patent/AU2005252962B2/en not_active Ceased
  • 2005-06-09 US US10/571,940 patent/US20080229769A1/en not_active Abandoned

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