WO2016166845A1 - 冷凍サイクル装置 - Google Patents
冷凍サイクル装置 Download PDFInfo
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- WO2016166845A1 WO2016166845A1 PCT/JP2015/061603 JP2015061603W WO2016166845A1 WO 2016166845 A1 WO2016166845 A1 WO 2016166845A1 JP 2015061603 W JP2015061603 W JP 2015061603W WO 2016166845 A1 WO2016166845 A1 WO 2016166845A1
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- heat exchanger
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- cycle apparatus
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- 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
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- 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
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- 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
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- 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
- F25B41/00—Fluid-circulation arrangements
- F25B41/30—Expansion means; Dispositions thereof
- F25B41/385—Dispositions with two or more expansion means arranged in parallel on a refrigerant line leading to the same evaporator
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- 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
- F25B41/00—Fluid-circulation arrangements
- F25B41/30—Expansion means; Dispositions thereof
- F25B41/39—Dispositions with two or more expansion means arranged in series, i.e. multi-stage expansion, on a refrigerant line leading to the same evaporator
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- 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
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- 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
- F25B2313/003—Indoor unit with water as a heat sink or heat source
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- 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
- F25B2339/00—Details of evaporators; Details of condensers
- F25B2339/04—Details of condensers
- F25B2339/047—Water-cooled condensers
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- 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
- F25B2500/00—Problems to be solved
- F25B2500/19—Calculation of parameters
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- 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
- F25B2600/00—Control issues
- F25B2600/25—Control of valves
- F25B2600/2501—Bypass valves
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- 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
- F25B2600/00—Control issues
- F25B2600/25—Control of valves
- F25B2600/2509—Economiser valves
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- 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
- F25B2600/00—Control issues
- F25B2600/25—Control of valves
- F25B2600/2513—Expansion valves
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- 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
- F25B2700/19—Pressures
- F25B2700/193—Pressures of the compressor
- F25B2700/1933—Suction pressures
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- 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
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- 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
- F25B2700/2115—Temperatures of a compressor or the drive means therefor
- F25B2700/21151—Temperatures of a compressor or the drive means therefor at the suction side of the compressor
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- 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
- F25B2700/2117—Temperatures of an evaporator
- F25B2700/21175—Temperatures of an evaporator of the refrigerant at the outlet of the evaporator
Definitions
- the present invention relates to a refrigeration cycle apparatus including a refrigerant circuit in which a refrigerant circulates.
- Some conventional refrigeration cycle devices incorporate an internal heat exchanger that exchanges heat between the refrigerant flowing out of the condenser and the refrigerant flowing out of the evaporator.
- HFO-1234yf R1234yf
- HFO-1234ze has been used as a refrigerant for circulating the refrigeration cycle apparatus.
- the internal heat exchanger is said to be useful for improving the refrigerating capacity when a refrigerant such as HFO-1234yf is used (see, for example, Patent Document 1).
- Patent Document 1 includes a “compressor for compressing refrigerant, a condenser for condensing the compressed refrigerant, decompression / expansion means for decompressing / expanding the condensed refrigerant, and an evaporator for evaporating the decompressed / expanded refrigerant;
- R1234yf is used as the refrigerant
- the amount of heat exchange by the internal heat exchanger is The ratio of the heat exchange amount by the internal heat exchanger to the refrigeration capacity as a whole of the refrigeration capacity is set to 7% or more.
- the refrigeration cycle apparatus of Patent Document 1 is set so that the heat exchange amount in the internal heat exchanger is 7% or more of the refrigeration capacity of the entire apparatus. For this reason, since the length of the heat transfer part of the internal heat exchanger becomes long and the refrigerant pressure loss from the evaporator to the suction port of the compressor increases, there is a problem that the efficiency decreases.
- the present invention has been made to solve the above-described problems, and reduces the length of the heat transfer section of the internal heat exchanger when HFO-1234yf or HFO-1234ze is used as the refrigerant, and is efficient. It aims at providing the refrigerating-cycle apparatus which aims at improvement.
- the refrigeration cycle apparatus includes a refrigerant circuit in which a compressor, a condenser, a main expansion valve, and an evaporator are connected via a main pipe, a refrigerant that flows between the condenser and the main expansion valve, and evaporation Between the condenser and the internal heat exchanger, which exchanges heat between the refrigerant flowing between the compressor and the compressor and allows the refrigerant flowing out of the evaporator to flow into the suction side of the compressor
- a HIC heat exchanger connected in series to the internal heat exchanger, a bypass pipe that branches from between the condenser and the HIC heat exchanger, and leads the refrigerant to the compressor via the HIC heat exchanger, and condensation
- a sub-expansion valve that decompresses the refrigerant flowing into the bypass pipe from the condenser and flows out to the HIC heat exchanger, and the HIC heat exchanger includes the refrigerant that flows in from the condenser through the main pipe and the
- the HIC heat exchanger connected in series to the internal heat exchanger is configured to exchange heat between the refrigerant flowing from the condenser through the main pipe and the refrigerant flowing from the condenser through the bypass pipe. Therefore, since the amount of heat exchange by the internal heat exchanger can be reduced, even when using HFO-1234yf or HFO-1234ze as the refrigerant, the length of the heat transfer section of the internal heat exchanger is shortened, and Efficiency can be improved.
- FIG. 1 is a system configuration diagram including a refrigerant circuit diagram of a refrigeration cycle apparatus according to Embodiment 1 of the present invention.
- FIG. 2 is a Ph diagram illustrating an operating state of the refrigeration cycle apparatus of FIG. It is a flowchart which shows the control action at the time of the hot water supply driving
- FIG. 8 is a Ph diagram illustrating an operating state of the refrigeration cycle apparatus of FIG. 7. It is a flowchart which shows the control action at the time of the hot water supply driving
- FIG. 1 is a system configuration diagram including a refrigerant circuit diagram of a refrigeration cycle apparatus according to Embodiment 1 of the present invention.
- FIG. 1 shows a state when a heating operation for raising the temperature of water on the load side is performed.
- the refrigeration cycle apparatus 100 is configured such that the compressor 10, the four-way valve 20, the condenser 30, the main expansion valve 80, and the evaporator 60 are connected in an annular shape.
- a HIC (Heat Inter Changer) heat exchanger 50 and an internal heat exchanger 70 connected in series are disposed between the condenser 30 and the main expansion valve 80. That is, the refrigeration cycle apparatus 100 includes a refrigerant circuit in which the compressor 10, the condenser 30, the main expansion valve 80, and the evaporator 60 are connected via the main pipe 1, and between the condenser 30 and the main expansion valve 80.
- HIC Heat Inter Changer
- the refrigeration cycle apparatus 100 is a main pipe that circulates refrigerant to the compressor 10, the four-way valve 20, the condenser 30, the HIC heat exchanger 50, the internal heat exchanger 70, the main expansion valve 80, and the evaporator 60 as refrigerant pipes.
- the refrigeration cycle apparatus 100 includes a bypass pipe 2 that branches from between the condenser 30 and the HIC heat exchanger 50 and guides the refrigerant to the compressor 10 via the HIC heat exchanger 50.
- the bypass pipe 2 branches from the main pipe 1 extending from the outlet of the condenser 30 and bypasses part of the high-pressure liquid refrigerant that has flowed out of the condenser 30 to flow into the main pipe 1.
- the main pipe 1 extending from 70 is connected.
- the refrigeration cycle apparatus 100 has a sub-expansion valve 40 that decompresses the refrigerant flowing into the bypass pipe 2 from the condenser 30 and flows out to the HIC heat exchanger 50. That is, the bypass pipe 2 is configured to bypass a part of the high-pressure liquid refrigerant that has passed through the condenser 30 and pass the sub expansion valve 40 and the HIC heat exchanger 50.
- the compressor 10 is composed of, for example, an inverter compressor whose capacity can be controlled, and sucks and compresses the low-temperature and low-pressure gas refrigerant, and discharges it in the state of the high-temperature and high-pressure gas refrigerant.
- the four-way valve 20 switches the direction between the high-temperature and high-pressure gas refrigerant discharged from the compressor 10 and the low-temperature and low-pressure gas refrigerant sucked into the compressor 10.
- the condenser 30 is composed of, for example, a plate heat exchanger, and heats the high-temperature and high-pressure gas refrigerant discharged from the compressor 10 and passing through the four-way valve 20 by heat exchange with water.
- the secondary expansion valve 40 is disposed in the bypass pipe 2 and depressurizes the high-pressure liquid refrigerant that has passed through the condenser 30 to form a low-pressure two-phase refrigerant.
- the HIC heat exchanger 50 exchanges heat between the high-pressure liquid refrigerant that has flowed out of the condenser 30 and passed through the main pipe 1, and the low-pressure two-phase refrigerant that has been decompressed by the sub-expansion valve 40.
- the evaporator 60 includes, for example, a fin plate heat exchanger and the like, and evaporates the refrigerant by exchanging heat with air.
- the internal heat exchanger 70 has, for example, a double pipe, and exchanges heat between the high-pressure liquid refrigerant that has passed through the HIC heat exchanger 50 and the low-pressure gas refrigerant that has passed through the evaporator 60.
- the main expansion valve 80 decompresses the high-pressure liquid refrigerant that has passed through the internal heat exchanger 70 into a low-pressure two-phase refrigerant.
- a refrigerant circuit is formed in which the refrigerant is circulated sequentially to the compressor 10, the condenser 30, the sub-expansion valve 40, the HIC heat exchanger 50, the internal heat exchanger 70, the main expansion valve 80, and the evaporator 60.
- the refrigeration cycle apparatus 100 uses a mixed refrigerant containing HFO-1234yf or HFO-1234ze as a refrigerant.
- HFO-1234yf or HFO-1234ze as a refrigerant has a global warming potential (GWP) of 4.
- GWP global warming potential
- the GWP of R410A conventionally used is 2090
- the GWP of R407C is 1770. That is, HFO-1234yf or HFO-1234ze is a refrigerant having a smaller influence on the global environment than R410A and R407C.
- HFO-1234yf or HFO-1234ze has a feature that the discharge temperature from the compressor 10 is less likely to rise than R410A and R407C. Further, in the heating operation in which HFO-1234yf or HFO-1234ze is heated to increase the temperature of water, if the discharge temperature is increased by increasing the suction superheat degree of the compressor 10, the condensation pressure at the time of equivalent capacity output decreases. The efficiency is improved.
- FIG. 2 is a Ph diagram illustrating the operating state of the refrigeration cycle apparatus 100, where the vertical axis represents the refrigerant absolute pressure P [MPa ⁇ abs] and the horizontal axis represents the specific enthalpy h [kJ / kg]. .
- a low-temperature and low-pressure gaseous refrigerant is sucked into the compressor 10 (C01: compressor 10 suction port), compressed by the compressor 10, and discharged as a high-temperature and high-pressure gas.
- the high-temperature and high-pressure gas refrigerant discharged from the compressor 10 flows into the condenser 30 via the four-way valve 20.
- the high-temperature high-pressure gas refrigerant that has flowed into the condenser 30 radiates heat to the heat exchange medium, and becomes high-pressure liquid refrigerant.
- the high-pressure liquid refrigerant that has flowed out of the condenser 30 branches in two directions.
- One branched high-pressure liquid refrigerant flows into the sub-expansion valve 40 through the bypass pipe 2 and is decompressed and expanded to become a low-temperature and low-pressure gas-liquid two-phase refrigerant (C03: sub-expansion valve 40 outlet).
- the other branched high-pressure liquid refrigerant flows into the HIC heat exchanger 50 and exchanges heat with the low-temperature and low-pressure gas-liquid two-phase refrigerant that has flowed out of the sub-expansion valve 40 (T01) to become a high-pressure supercooled liquid refrigerant.
- Outflow (C04a: HIC heat exchanger 50 outlet).
- the low-temperature and low-pressure gas-liquid two-phase refrigerant that has flowed out of the sub-expansion valve 40 exchanges heat with the high-pressure liquid refrigerant that has flowed into the HIC heat exchanger 50 (T01) and flows out as medium-temperature and low-pressure gas refrigerant (C04b: HIC heat) Exchanger 50 outlet).
- the high-pressure supercooled liquid refrigerant that has flowed out of the HIC heat exchanger 50 flows into the internal heat exchanger 70, exchanges heat with the low-pressure and low-temperature gas refrigerant that has flowed out of the evaporator 60 and passed through the four-way valve 20 (T02), Further, it flows out as a liquid refrigerant having a high degree of supercooling (C05: outlet of internal heat exchanger 70).
- the supercooled liquid refrigerant that has flowed out of the internal heat exchanger 70 flows into the main expansion valve 80, is decompressed and expanded to become a low-pressure two-phase refrigerant, and flows into the evaporator 60 (C06: evaporator 60 inlet).
- the low-pressure two-phase refrigerant that has flowed into the evaporator 60 cools the air that is the heat exchange medium, evaporates, and flows out as a low-temperature and low-pressure gas refrigerant (C07: outlet of the evaporator 60).
- the low-temperature and low-pressure gas refrigerant that has flowed out of the evaporator 60 passes through the four-way valve 20 again, and then flows into the internal heat exchanger 70 and exchanges heat with the high-pressure liquid refrigerant that has flowed out of the HIC heat exchanger 50 (T02). Then, it flows out as medium temperature and low pressure gas refrigerant (C08: internal heat exchanger 70 outlet).
- the HIC heat exchanger 50 can be configured with a narrower pipe than the internal heat exchanger 70, and can have a compact configuration.
- the refrigeration cycle apparatus 100 includes a state detection unit that detects the state of the refrigerant flowing in the refrigerant circuit, and a microcomputer such as a DSP, for example.
- the refrigeration cycle apparatus 100 includes a sub-expansion valve 40 and a main expansion valve 80 based on the detection result by the state detection unit. And a control device 90 for controlling the opening degree.
- the state detection unit detects the pressure sensor 110 that detects the suction pressure Ps that is the pressure of the gas refrigerant sucked into the compressor 10 and the HIC outlet temperature Tho that is the temperature of the gas refrigerant that flows out of the HIC heat exchanger 50.
- the HIC outlet temperature sensor 120 and the evaporator outlet temperature sensor 130 for detecting the evaporator outlet temperature The which is the temperature of the gas refrigerant flowing out of the evaporator 60 are provided.
- the control device 90 has a superheat degree calculation unit 90a that calculates a first superheat degree that is a superheat degree at the outlet of the HIC heat exchanger 50 using a result of detection by the state detection part, and a first superheat degree is preset.
- control device 90 calculates the saturation temperature f (Ps) of the suction pressure Ps detected by the pressure sensor 110 and calculates the saturation temperature f (Ps) from the HIC outlet temperature Tho detected by the HIC outlet temperature sensor 120. ) Is subtracted to calculate a first superheat degree SHa that calculates the first superheat degree SHh that is the degree of heating of the gas outlet of the HIC heat exchanger 50, and the first superheat degree SHh calculated in the superheat degree calculator 90a, A superheat degree determination unit 90b that compares a first set value that is a preset allowable lower limit and determines whether or not the first superheat degree SHh is less than the first set value, and a determination by the superheat degree determination unit 90b And a valve control unit 90c that controls the opening degree of the sub-expansion valve 40 and the main expansion valve 80.
- the superheat degree determination unit 90b compares the first superheat degree SHh with a second set value that is a preset allowable upper limit, 1 has a function of determining whether the degree of superheat SHh is greater than the second set value.
- the valve control unit 90c is configured to reduce the opening degree of the sub-expansion valve 40 when the superheat degree determination unit 90b determines that the first superheat degree SHh is less than the first set value. Further, the valve control unit 90c increases the opening degree of the sub-expansion valve 40 when the superheat degree determination unit 90b determines that the first superheat degree SHh is larger than the second set value.
- valve control part 90c maintains the opening degree of the sub expansion valve 40, when it determines with 1st superheat degree SHh being below 2nd setting value in the superheat degree determination part 90b. That is, in the first embodiment, the target range is set to a range that is not less than the first set value and not more than the second set value.
- the superheat degree calculation unit 90 a subtracts the saturation temperature f (Ps) of the suction pressure Ps from the evaporator outlet temperature The detected by the evaporator outlet temperature sensor 130 to obtain the superheat degree at the outlet of the evaporator 60. It has a function of calculating the second superheat degree SHe.
- the superheat degree determination unit 90b compares the second superheat degree SHe calculated by the superheat degree calculation unit 90a with a preset third set value (target value), and the second superheat degree SHe is the third set value. It has a function to determine whether or not it is less than.
- the valve control unit 90c reduces the opening degree of the main expansion valve 80 when the second superheat degree determination unit 90b determines that the second superheat degree SHe is less than the third set value, and the second superheat degree SHe is When it is determined that the value is greater than or equal to the third set value, the opening of the main expansion valve 80 is increased. That is, the valve control unit 90c controls the opening degree of the main expansion valve 80 so that the second superheat degree SHe becomes the sixth set value that is the target value.
- FIG. 3 is a flowchart showing a control operation during hot water supply operation by the control device 90.
- the superheat degree calculation unit 90a inputs the suction pressure Ps detected by the pressure sensor 110 (FIG. 3: step S101), and inputs the HIC outlet temperature Tho detected by the HIC outlet temperature sensor 120 (FIG. 3: Step S102).
- the superheat degree calculation unit 90a calculates the saturation temperature f (Ps) of the suction pressure Ps, subtracts the calculated f (Ps) from the HIC outlet temperature Tho, and the first superheat degree at the gas outlet of the HIC heat exchanger 50. SHh is calculated (FIG. 3: step S103).
- the superheat degree determination unit 90b compares the first superheat degree SHh calculated by the superheat degree calculation unit 90a with the first set value, and determines whether or not the first superheat degree SHh is less than the first set value. (FIG. 3: Step S104). When the superheat degree determination unit 90b determines that the first superheat degree SHh is less than the first set value (FIG. 3: Step S104 / Yes), the valve control unit 90c determines the opening degree of the sub expansion valve 40. The heat exchange amount of the HIC heat exchanger 50 is reduced (FIG. 3: Step S105). On the other hand, when the superheat degree determination unit 90b determines that the first superheat degree SHh is greater than or equal to the first set value (FIG.
- valve control unit 90c determines that the first superheat degree SHh is The second set value is compared to determine whether or not the first superheat degree SHh is greater than the second set value (FIG. 3: step S106).
- the superheat degree determination unit 90b compares the first superheat degree SHh calculated by the superheat degree calculation unit 90a with the second set value, and determines whether the first superheat degree SHh is larger than the second set value. Determination is made (FIG. 3: step S106).
- the valve control unit 90c increases the opening degree of the sub expansion valve 40. Then, the heat exchange amount of the HIC heat exchanger 50 is increased (FIG. 3: step S107).
- the valve control unit 90c presents the current sub-expansion valve.
- the opening degree of 40 is maintained (FIG. 3: Step S108). That is, the valve control unit 90c controls the opening degree of the sub-expansion valve 40 so that the first degree of superheat falls within a target range that is not less than the first set value and not more than the second set value.
- the superheat degree calculation unit 90a inputs the evaporator outlet temperature The detected by the evaporator outlet temperature sensor 130 (FIG. 3: step S109).
- the superheat degree calculation unit 90a calculates the second superheat degree SHe at the outlet of the evaporator 60 by subtracting the saturation temperature f (Ps) of the suction pressure Ps from the evaporator outlet temperature The input from the evaporator outlet temperature sensor 130.
- the superheat degree determination unit 90b compares the second superheat degree SHe calculated by the superheat degree calculation unit 90a with the third set value, and determines whether the second superheat degree SHe is less than the third set value. (FIG. 3: Step S111).
- the valve control unit 90c determines the degree of opening of the main expansion valve 80 when the superheat degree determination unit 90b determines that the second superheat degree SHe is less than the third set value (FIG. 3: Step S111 / Yes).
- the heat exchange amount of the evaporator 60 is suppressed by reducing the size (FIG. 3: Step S112).
- the valve control unit 90c opens the main expansion valve 80 when the superheat degree determination unit 90b determines that the second superheat degree SHe is equal to or greater than the third set value (FIG. 3: step S111 / No).
- the degree is increased and the heat exchange amount of the evaporator 60 is increased (FIG. 3: step S113).
- FIG. 4 is a characteristic diagram showing a simulation result of the relationship between the ratio of the heat exchange amount of the internal heat exchanger 70 to the total refrigeration capacity of the refrigeration cycle apparatus 100 (hereinafter simply referred to as “total refrigeration capacity”) and COP. is there.
- total refrigeration capacity the total refrigeration capacity of the refrigeration cycle apparatus 100
- COP Coefficient of Performance: Performance coefficient
- the suction superheat degree of the compressor 10 is increased.
- the COP is reduced because the discharge temperature of the compressor 10 is reduced and the increase in the discharge temperature is reduced.
- the internal heat exchanger 70 The refrigerant pressure loss on the low-pressure gas side increases and COP decreases.
- the refrigeration cycle apparatus 100 if the ratio of the heat exchange amount of the internal heat exchanger 70 to the total refrigeration capacity is in the range of 2.4% or more and less than 7%, the COP takes a good value. Can drive in the area.
- a region where COP takes a good value is a region where COP is 100% or more. That is, the refrigeration cycle apparatus 100 sets the length of the heat transfer portion of the internal heat exchanger 70 so that the ratio of the heat exchange amount of the internal heat exchanger 70 to the total refrigeration capacity is 2.4% or more and less than 7%. It is set.
- FIG. 5 is a characteristic diagram showing the relationship between the ratio of the heat exchange amount of the internal heat exchanger 70 to the total refrigeration capacity and the first superheat degree SHh at the outlet of the HIC heat exchanger 50.
- the adjustment method of the ratio of the heat exchange amount of the internal heat exchanger 70 to the total refrigeration capacity will be described.
- the first lower limit of the first superheat degree SHh is set so that the ratio of the heat exchange amount of the internal heat exchanger 70 to the total refrigeration capacity is in the range of 2.4% or more and less than 7%.
- the set value is set to 15 ° C.
- the second set value that is the allowable upper limit of the first superheat degree SHh is set to 44 ° C. That is, the valve control unit 90c is configured to control the opening degree of the sub expansion valve 40 so that the first superheat degree SHh becomes a value within the target range.
- FIG. 6 is a characteristic diagram showing the relationship between the ratio of the heat exchange amount of the HIC heat exchanger 50 to the heat exchange amount of the internal heat exchanger 70 and the COP in the refrigeration cycle apparatus 200.
- the relationship between the heat exchange amount of the HIC heat exchanger 50 and the internal heat exchanger 70 and the region where the COP of the refrigeration cycle apparatus 100 takes a good value will be described.
- the HIC heat exchanger 50 since the HIC heat exchanger 50 is on the upstream side and the internal heat exchanger 70 is on the downstream side, if the heat exchange amount of the HIC heat exchanger 50 is increased, the internal heat exchanger 50 The temperature of the high-pressure liquid refrigerant flowing into 70 decreases. That is, as the heat exchange amount of the HIC heat exchanger 50 increases, the heat exchange amount of the internal heat exchanger 70 decreases, and as shown in FIG. There is a peak value of COP with respect to the ratio of the heat exchange amount of the exchanger 50.
- the ratio of the heat exchange amount of the HIC heat exchanger 50 to the heat exchange amount of the internal heat exchanger 70 is set to be 160% or more and 700% or less.
- the refrigeration cycle apparatus 100 includes the HIC heat exchanger 50 connected in series to the internal heat exchanger 70, and the HIC heat exchanger 50 is connected to the main heat exchanger 50 from the condenser 30.
- a configuration is adopted in which heat exchange is performed between the high-pressure refrigerant flowing in through the pipe 1 and the two-phase refrigerant flowing in from the condenser 30 via the sub-expansion valve 40 on the bypass pipe 2. For this reason, since the amount of heat exchange by the internal heat exchanger 70 can be reduced, the length of the heat transfer portion of the internal heat exchanger 70 that causes the refrigerant pressure loss on the suction side of the compressor 10 is more than necessary. The operation in the region where the COP is high can be realized without increasing the length.
- the amount of heat exchange by the internal heat exchanger 70 can be reduced. Therefore, even when HFO-1234yf or HFO-1234ze is used as the refrigerant, heat transfer of the internal heat exchanger 70 is achieved. The length of the part can be shortened and the efficiency can be improved.
- the valve control unit 90c employs a configuration in which the opening degree of the main expansion valve 80 is controlled so that the second superheat degree becomes a preset target value (third set value), the secondary expansion is performed. The influence of the control of the valve 40 on the evaporator 60 side can be minimized.
- the internal heat exchanger has a long double tube configuration, there is a problem that productivity is lowered.
- the length of the heat transfer section of the internal heat exchanger 70 is long. Therefore, productivity can be improved.
- the bypass pipe 2 passing through the HIC heat exchanger 50 is configured to flow a small amount of two-phase refrigerant, the influence of the pressure loss on the efficiency of the refrigeration cycle apparatus 200 is suppressed. Therefore, according to the refrigeration cycle apparatus 200 having the HIC heat exchanger 50, the length of the heat transfer section of the internal heat exchanger 70 can be shortened and efficiency can be improved.
- the HIC heat exchanger 50 can be configured with a narrower pipe than the internal heat exchanger 70, the apparatus can be made compact. Furthermore, by using a thin pipe for the HIC heat exchanger 50 and making it more compact, the dimensions of the equipment can be made smaller than in the conventional configuration, improving installation, reducing equipment weight, and reducing costs. Can be realized.
- the refrigeration cycle apparatus 100 of the first embodiment is configured to use HFO-1234yf or HFO-1234ze having a low global warming potential, it is possible to reduce the influence on the global environment. .
- FIG. 7 is a system configuration diagram including a refrigerant circuit diagram of the refrigeration cycle apparatus 200 according to the second embodiment.
- FIG. 7 shows a state when a heating operation for increasing the temperature of water on the load side is performed.
- the same reference numerals are used for the same constituent members as those in the first embodiment.
- the refrigeration cycle apparatus 200 includes, for example, a capacity-controllable inverter compressor or the like, and includes a compressor 15 that sucks low-temperature low-pressure gas refrigerant, compresses it, and discharges it into a high-temperature high-pressure gas refrigerant state.
- the compressor 15 has an injection port (not shown) and an intermediate chamber (not shown) for injecting an intermediate pressure refrigerant (intermediate pressure refrigerant) flowing into the bypass pipe 2 and flowing out of the HIC heat exchanger 50 in the compression process. have. That is, the gas refrigerant flowing out of the HIC heat exchanger 50 is injected into an intermediate chamber provided in the pressure chamber of the compressor 15 through the injection port.
- FIG. 8 is a Ph diagram showing the operating state of the refrigeration cycle apparatus 200, where the vertical axis represents the absolute pressure P [MPa ⁇ abs] of the refrigerant and the horizontal axis represents the specific enthalpy h [kJ / kg]. .
- a low-temperature and low-pressure gaseous refrigerant (C11: outlet of the internal heat exchanger 70) is sucked into the compressor 15, compressed by the compressor 15, and discharged as a high-temperature and high-pressure gas.
- the high-temperature and high-pressure gas refrigerant discharged from the compressor 15 flows into the condenser 30 via the four-way valve 20.
- the high-temperature high-pressure gas refrigerant that has flowed into the condenser 30 radiates heat to the heat exchange medium, and becomes high-pressure liquid refrigerant.
- the high-pressure liquid refrigerant that has flowed out of the condenser 30 (C12: outlet of the condenser 30) branches in two directions.
- One of the branched high-pressure liquid refrigerant flows into the sub-expansion valve 40 through the bypass pipe 2 and is decompressed and expanded to become a gas-liquid two-phase refrigerant of medium temperature and medium pressure (C13: sub-expansion valve 40 outlet).
- the other branched high-pressure liquid refrigerant flows into the HIC heat exchanger 50 and exchanges heat with the medium-temperature and medium-pressure gas-liquid two-phase refrigerant that has flowed out of the sub-expansion valve 40 (T11) to become a high-pressure supercooled liquid refrigerant.
- C14a HIC heat exchanger 50 outlet
- the medium-temperature and medium-pressure gas-liquid two-phase refrigerant that has flowed out of the sub-expansion valve 40 exchanges heat with the high-pressure liquid refrigerant that has flowed into the HIC heat exchanger 50 (T11) to become heated gas (C14b: HIC heat exchanger 50 outlet). Then, it is injected into the intermediate pressure of the compressor 15 (C15: intermediate pressure merging section).
- the high-pressure supercooled liquid refrigerant that has flowed out of the HIC heat exchanger 50 flows into the internal heat exchanger 70, exchanges heat with the low-pressure and low-temperature gas refrigerant that has flowed out of the evaporator 60 and passed through the four-way valve 20 (T12), Furthermore, it flows out as a liquid refrigerant with a large degree of supercooling (C16: outlet of internal heat exchanger 70).
- the supercooled liquid refrigerant that has flowed out of the internal heat exchanger 70 flows into the main expansion valve 80, is decompressed and expanded to become a low-pressure two-phase refrigerant, and flows into the evaporator 60 (C17: internal heat exchanger 70 inlet).
- the low-pressure two-phase refrigerant that has flowed into the evaporator 60 cools the air that is the heat exchange medium, evaporates, and flows out as a low-temperature and low-pressure gas refrigerant (C18: outlet of the evaporator 60).
- the low-temperature and low-pressure gas refrigerant that has flowed out of the evaporator 60 passes through the four-way valve 20 again, then flows into the internal heat exchanger 70, and exchanges heat with the high-pressure liquid refrigerant that has flowed out of the HIC heat exchanger 50 (T12). ), A gas refrigerant having a high degree of superheat, and sucked into the compressor 15 again.
- the low-pressure gas before being sucked into the compressor 10 flows through the main pipe 1 on the gas side of the internal heat exchanger 70, the low-pressure pressure loss increases as the pipe length increases, and the refrigeration cycle apparatus 200 It becomes a factor to deteriorate efficiency.
- the HIC heat exchanger 50 can be configured with a narrower pipe than the internal heat exchanger 70, and can have a compact configuration.
- the refrigeration cycle apparatus 200 includes a state detection unit that detects the state of the refrigerant flowing through the refrigerant circuit, and a control device 190 that controls the opening degrees of the sub-expansion valve 40 and the main expansion valve 80 based on the detection result of the state detection unit. And have.
- the state detection unit of the second embodiment includes a pressure sensor 110 that detects the suction pressure Ps that is the pressure of the gas refrigerant sucked into the compressor 10, and the HIC that is the temperature of the gas refrigerant that flows out of the HIC heat exchanger 50.
- the HIC outlet temperature sensor 120 that detects the outlet temperature Th
- the HIC inlet temperature sensor 210 that detects the HIC inlet temperature Thi, which is the temperature of the gas refrigerant flowing into the HIC heat exchanger 50
- the internal heat exchanger 70 A suction temperature sensor 230 that detects a suction temperature Ts that is a temperature of a gas refrigerant sucked into the compressor 15, a pressure sensor 110, an HIC outlet temperature sensor 120, and an HIC inlet temperature sensor 210 are provided.
- the control device 190 subtracts the HIC inlet temperature Thi detected by the HIC inlet temperature sensor 210 from the HIC outlet temperature Th detected by the HIC outlet temperature sensor 120, and determines the degree of superheat of the gas outlet of the HIC heat exchanger 50.
- a superheat degree calculation unit 190a for calculating a certain first superheat degree SHh, the first superheat degree SHh calculated in the superheat degree calculation unit 190a, and a fourth set value that is a preset allowable lower limit are compared, Based on the results of the determination by the superheat degree determination unit 190b and the superheat degree determination unit 190b that determine whether or not the one superheat degree SHh is less than the fourth set value, the sub-expansion valve 40 and the main expansion valve 80 are opened. And a valve control unit 190c for controlling the degree.
- the superheat degree determination unit 190b compares the first superheat degree SHh with the fifth set value that is a preset allowable upper limit, It has a function of determining whether or not 1 superheat degree SHh is larger than the fifth set value.
- the valve control unit 190c reduces the opening degree of the sub-expansion valve 40 when the superheat degree determination unit 190b determines that the first superheat degree SHh is less than the fourth set value.
- the valve control unit 190c increases the opening degree of the sub-expansion valve 40 when the superheat degree determination unit 190b determines that the first superheat degree SHh is larger than the fifth set value.
- valve control part 190c maintains the opening degree of the sub expansion valve 40, when it determines with 1st superheat degree SHh being below 5th setting value in the superheat degree determination part 190b. That is, in the second embodiment, the target range is set to a range that is not less than the fourth set value and not more than the fifth set value.
- the superheat degree calculation unit 190a calculates the saturation temperature f (Ps) of the suction pressure Ps detected by the pressure sensor 110, and subtracts the saturation temperature f (Ps) from the suction temperature Ts detected by the suction temperature sensor 230.
- the third superheat degree SHs that is the superheat degree of the suction port of the compressor 15 is calculated.
- the superheat degree determination unit 190b compares the third superheat degree SHs calculated by the superheat degree calculation unit 190a with a preset sixth set value (target value), and the third superheat degree SHs is the sixth set value. It has a function to determine whether or not it is less than.
- the valve control unit 190c reduces the opening of the main expansion valve 80, and the third superheat degree SHs When it is determined that the value is equal to or larger than the sixth set value, the opening degree of the main expansion valve 80 is increased. That is, the valve control unit 190c controls the opening degree of the main expansion valve 80 so that the third superheat degree SHs becomes the sixth set value that is the target value.
- FIG. 9 is a flowchart showing a control operation during hot water supply operation by control device 190.
- the superheat degree calculation unit 190a inputs the HIC inlet temperature Thi detected by the HIC inlet temperature sensor 210 (FIG. 9: Step S201), and inputs the HIC outlet temperature Tho detected by the HIC outlet temperature sensor 120 ( FIG. 9: Step S202).
- the superheat degree calculation unit 190a calculates the first superheat degree SHh at the gas outlet of the HIC heat exchanger 50 by subtracting the HIC inlet temperature Thi from the HIC outlet temperature Tho (FIG. 9: Step S203).
- the superheat degree determination unit 190b compares the first superheat degree SHh calculated by the superheat degree calculation unit 190a with the fourth set value, and determines whether or not the first superheat degree SHh is less than the fourth set value. (FIG. 9: Step S204). When the superheat degree determination unit 190b determines that the first superheat degree SHh is less than the fourth set value (FIG. 9: Step S204 / Yes), the valve control unit 190c determines the opening degree of the sub expansion valve 40. The heat exchange amount of the HIC heat exchanger 50 is suppressed by reducing the size (FIG. 9: Step S205).
- the superheat degree determination unit 190b compares the first superheat degree SHh with the fifth set value. Then, it is determined whether or not the first superheat degree SHh is larger than the fifth set value (FIG. 9: Step S206).
- the valve control unit 190c increases the opening degree of the sub expansion valve 40. Then, the heat exchange amount of the HIC heat exchanger 50 is increased (FIG. 9: Step S207).
- the valve control unit 190c presents the current sub-expansion valve.
- the opening degree of 40 is maintained (FIG. 9: Step S208). That is, the valve control unit 190c controls the opening degree of the sub-expansion valve 40 so that the first degree of superheat falls within a target range that is not less than the fourth set value and not more than the fifth set value.
- the superheat degree calculation unit 190a inputs the suction pressure Ps detected by the pressure sensor 110 (FIG. 9: Step S209), and inputs the suction temperature Ts detected by the suction temperature sensor 230 (FIG. 9: Step). S210).
- the superheat degree calculation unit 190a calculates the saturation temperature f (Ps) of the suction pressure Ps, and subtracts the saturation temperature f (Ps) from the suction temperature Ts to calculate the third superheat degree SHs of the suction port of the compressor 15. (FIG. 9: Step S211).
- the superheat degree determination unit 190b compares the third superheat degree SHs calculated by the superheat degree calculation unit 190a with the sixth set value, and determines whether the third superheat degree SHs is less than the sixth set value. (FIG. 9: Step S212). When the superheat degree determination unit 190b determines that the third superheat degree SHs is less than the sixth set value (FIG. 9: Step S212 / Yes), the valve control unit 190c determines the opening degree of the main expansion valve 80. The heat exchange amount of the evaporator 60 is suppressed by reducing the size (FIG. 9: Step S213).
- the valve control unit 190c opens the main expansion valve 80. The degree is increased, and the heat exchange amount of the evaporator 60 is increased (FIG. 9: Step S214).
- FIG. 10 is a characteristic diagram showing the result of simulating the relationship between the ratio of the heat exchange amount of the internal heat exchanger 70 to the total refrigeration capacity of the refrigeration cycle apparatus 200 and the COP.
- region where COP of the refrigerating-cycle apparatus 200 takes a favorable value is demonstrated.
- the COP in the refrigeration cycle apparatus 200 has a peak value in the vicinity where the ratio of the heat exchange amount of the internal heat exchanger 70 to the total refrigeration capacity is 5.5%. That is, if the length of the heat transfer section of the internal heat exchanger 70 is too short, the suction superheat degree of the compressor 10 becomes small and the increase in the discharge temperature of the compressor 10 becomes small, so that the COP becomes low. On the other hand, if the length of the heat transfer section of the internal heat exchanger 70 is too long, the refrigerant pressure loss on the low-pressure gas side of the internal heat exchanger 70 increases and COP decreases.
- the refrigeration cycle apparatus 200 is operated in a region where the COP takes a good value if the ratio of the heat exchange amount of the internal heat exchanger 70 to the total refrigeration capacity is less than 7%. Can do. Also in the second embodiment, a region where COP takes a good value is a region where COP is 100% or more. That is, in the refrigeration cycle apparatus 200, the length of the heat transfer portion of the internal heat exchanger 70 is set so that the ratio of the heat exchange amount of the internal heat exchanger 70 to the total refrigeration capacity is less than 7%.
- FIG. 11 is a characteristic diagram showing the relationship between the ratio of the heat exchange amount of the internal heat exchanger 70 to the total refrigeration capacity of the refrigeration cycle apparatus 200 and the first superheat degree SHh at the outlet of the HIC heat exchanger 50.
- the adjustment method of the ratio of the heat exchange amount of the internal heat exchanger 70 to the total refrigeration capacity will be described. As shown in FIG. 11, by controlling the first superheat degree SHh at the outlet of the HIC heat exchanger 50, the ratio of the heat exchange amount of the internal heat exchanger 70 to the total refrigeration capacity can be controlled.
- the valve control unit 190c in order to set the ratio of the heat exchange amount of the internal heat exchanger 70 to the total refrigeration capacity to be less than 7%, has a first superheat degree SHh of 15 ° C. or less, which is the target range.
- the degree of opening of the sub expansion valve 40 is controlled so as to be in the range.
- FIG. 12 is a characteristic diagram showing the relationship between the ratio of the heat exchange amount of the HIC heat exchanger 50 to the heat exchange amount of the internal heat exchanger 70 and the COP in the refrigeration cycle apparatus 200.
- FIG. 12 the relationship between the heat exchange amount of the HIC heat exchanger 50 and the internal heat exchanger 70 and the region where the COP of the refrigeration cycle apparatus 200 takes a good value will be described.
- the HIC heat exchanger 50 is on the upstream side and the internal heat exchanger 70 is on the downstream side, if the heat exchange amount of the HIC heat exchanger 50 is increased, the internal heat exchanger 50
- the temperature of the high-pressure liquid refrigerant flowing into 70 decreases. That is, as the heat exchange amount of the HIC heat exchanger 50 increases, the heat exchange amount of the internal heat exchanger 70 decreases, and as shown in FIG. 12, the HIC heat with respect to the heat exchange amount of the internal heat exchanger 70
- the ratio of the heat exchange amount of the HIC heat exchanger 50 to the heat exchange amount of the internal heat exchanger 70 is set to be 125% or more and 280% or less.
- the refrigeration cycle apparatus 200 has the HIC heat exchanger 50 connected in series to the internal heat exchanger 70, and the HIC heat exchanger 50 is connected to the condenser 30 from the main unit.
- a configuration is adopted in which heat is exchanged between the refrigerant flowing in through the pipe 1 and the refrigerant flowing in from the condenser 30 via the sub-expansion valve 40 on the bypass pipe 2. For this reason, since the amount of heat exchange by the internal heat exchanger 70 can be reduced, the length of the heat transfer portion of the internal heat exchanger 70 that causes the refrigerant pressure loss on the suction side of the compressor 10 is more than necessary. The operation in the region where the COP is high can be realized without increasing the length.
- the amount of heat exchange by the internal heat exchanger 70 can be reduced. Therefore, even when HFO-1234yf or HFO-1234ze is used as the refrigerant, heat transfer of the internal heat exchanger 70 is achieved. The length of the part can be shortened and the efficiency can be improved.
- the valve control unit 190c employs a configuration in which the opening degree of the main expansion valve 80 is controlled so that the third superheat degree becomes a preset target value (sixth set value). The influence of the control of the valve 40 on the evaporator 60 side can be minimized.
- the length of the heat transfer section of the internal heat exchanger 70 can be shortened, so that productivity can be improved. Furthermore, since the bypass pipe 2 passing through the HIC heat exchanger 50 is configured to flow a small amount of two-phase refrigerant, the HIC heat exchanger 50 is configured with a pipe that is thinner than the internal heat exchanger 70. Can be made compact. In addition, by reducing the size of the HIC heat exchanger 50 by using a thin pipe, the size of the device can be made smaller than that of the conventional configuration, thereby improving the installation property, reducing the weight of the device, and reducing the cost. Can be realized. In addition, since the refrigeration cycle apparatus 100 of the second embodiment is configured to use HFO-1234yf or HFO-1234ze having a low global warming potential, the influence on the global environment can be reduced. .
- each embodiment mentioned above is a suitable specific example in a refrigerating-cycle apparatus, and the technical scope of this invention is not limited to these aspects.
- a mixed refrigerant containing HFO-1234yf or HFO-1234ze is exemplified as the refrigerant used by the refrigeration cycle apparatuses 100 and 200.
- the present invention is not limited to this, and for example, HFO A single refrigerant of ⁇ 1234yf or HFO-1234ze may be used.
- a mixed refrigerant containing HFO-1234yf or HFO-1234ze a mixed refrigerant obtained by mixing HFO-1234yf or HFO-1234ze and R32 may be used.
- the detection result used for the calculation of the first superheat degree is not limited to that by each sensor illustrated in each embodiment, and for example, the calculation method in the first embodiment may be adopted in the second embodiment.
- the calculation method in the second embodiment may be adopted in the first embodiment.
- the control device 90 according to the first embodiment may perform the determination process using the third superheat degree
- the control device 190 according to the second embodiment may perform the determination process using the second superheat degree. May be performed.
Abstract
Description
図1は、本発明の実施の形態1に係る冷凍サイクル装置の冷媒回路図を含むシステム構成図である。図1には、負荷側の水の温度を上げる加熱運転を実施している時の状態が示されている。
次に、図7~図12を参照して、本発明の実施の形態2に係る冷凍サイクル装置の構成及び動作について説明する。図7は、本実施の形態2に係る冷凍サイクル装置200の冷媒回路図を含むシステム構成図である。図7には、負荷側の水の温度を上げる加熱運転を実施している時の状態が示されている。前述した実施の形態1と同一の構成部材については同一の符号を用いるものとする。
Claims (13)
- 圧縮機、凝縮器、主膨張弁、及び蒸発器が主配管を介して接続された冷媒回路と、
前記凝縮器と前記主膨張弁との間に流れる冷媒と、前記蒸発器と前記圧縮機との間に流れる冷媒とを熱交換させて、前記蒸発器を流出した冷媒を前記圧縮機の吸入側に流入させる内部熱交換器と、
前記凝縮器と前記内部熱交換器との間に設けられ、前記内部熱交換器に直列接続されたHIC熱交換器と、
前記凝縮器と前記HIC熱交換器との間から分岐し、前記HIC熱交換器を経由して前記圧縮機に冷媒を導くバイパス配管と、
前記凝縮器から前記バイパス配管に流入する冷媒を減圧して前記HIC熱交換器へ流出する副膨張弁と、を有し、
前記HIC熱交換器は、前記凝縮器から前記主配管を通じて流入する冷媒と、前記凝縮器から前記副膨張弁を介して流入する冷媒とを熱交換させるものである冷凍サイクル装置。 - 前記冷媒回路を流れる冷媒の状態を検知する状態検知部と、
前記状態検知部による検知の結果をもとに前記副膨張弁の開度を制御する制御装置と、をさらに有し、
前記制御装置は、
前記状態検知部による検知の結果を用いて前記HIC熱交換器の出口の過熱度である第1過熱度を演算する過熱度演算部と、
前記第1過熱度が予め設定された目標範囲となるように、前記副膨張弁の開度を制御する弁制御部と、を有する請求項1に記載の冷凍サイクル装置。 - 前記状態検知部は、
前記圧縮機に吸入される冷媒の圧力である吸入圧力を検知する圧力センサと、
前記HIC熱交換器を流出する冷媒の温度であるHIC出口温度を検知するHIC出口温度センサと、を有し、
前記過熱度演算部は、前記圧力センサにおいて検知された前記吸入圧力から飽和温度を算出した上で、HIC出口温度センサにおいて検知された前記HIC出口温度から前記飽和温度を減算して前記第1過熱度を演算する請求項2に記載の冷凍サイクル装置。 - 前記状態検知部は、
前記HIC熱交換器を流出する冷媒の温度であるHIC出口温度を検知するHIC出口温度センサと、
前記HIC熱交換器に流入するガス冷媒の温度であるHIC入口温度を検知するHIC入口温度センサと、を有し、
前記過熱度演算部は、前記HIC出口温度センサにおいて検知された前記HIC出口温度から前記HIC入口温度センサにおいて検知された前記HIC入口温度を減算して、前記第1過熱度を演算する請求項2に記載の冷凍サイクル装置。 - 前記状態検知部は、
前記圧縮機に吸入される冷媒の圧力である吸入圧力を検知する圧力センサと、
前記蒸発器を流出する冷媒の温度である蒸発器出口温度を検知する蒸発器出口温度センサを有し、
前記過熱度演算部は、前記圧力センサ及び前記蒸発器出口温度センサによる検知の結果をもとに前記蒸発器の出口の過熱度である第2過熱度を演算する機能を有し、
前記弁制御部は、
前記主膨張弁の開度を制御する機能を有すると共に、
前記第2過熱度が予め設定された目標値となるように、前記主膨張弁の開度を制御する請求項2~4の何れか一項に記載の冷凍サイクル装置。 - 前記状態検知部は、
前記圧縮機に吸入されるガス冷媒の圧力である吸入圧力を検知する圧力センサと、
前記内部熱交換器から流出して前記圧縮機に吸入されるガス冷媒の温度である吸入温度を検知する吸入温度センサと、を有し、
前記過熱度演算部は、前記圧力センサ及び前記吸入温度センサによる検知の結果をもとに前記圧縮機の吸入口の過熱度である第3過熱度を演算する機能を有し、
前記弁制御部は、
前記主膨張弁の開度を制御する機能を有すると共に、
前記第3過熱度が予め設定された目標値となるように、前記主膨張弁の開度を制御する請求項2~4の何れか一項に記載の冷凍サイクル装置。 - 全冷凍能力に対する前記内部熱交換器の熱交換量の比率が7%未満となるように、前記目標範囲が設定されている請求項2~6の何れか一項に記載の冷凍サイクル装置。
- 全冷凍能力に対する前記内部熱交換器の熱交換量の比率が2.4%以上となるように、前記目標範囲が設定されている請求項7に記載の冷凍サイクル装置。
- 前記バイパス配管は、前記内部熱交換器の出口から延びる前記主配管に連結されている請求項1~8の何れか一項に記載の冷凍サイクル装置。
- 前記圧縮機は、前記バイパス配管に流入し前記HIC熱交換器を流出した冷媒をインジェクションするインジェクションポートを有している請求項1~8の何れか一項に記載の冷凍サイクル装置。
- 前記内部熱交換器の熱交換量に対する前記HIC熱交換器の熱交換量の比率は、160%以上700%以下となるように設定されている請求項9に記載の冷凍サイクル装置。
- 前記内部熱交換器の熱交換量に対する前記HIC熱交換器の熱交換量の比率は、125%以上280%以下となるように設定されている請求項10に記載の冷凍サイクル装置。
- 前記主配管及び前記バイパス配管を循環させる冷媒として、HFO-1234yfもしくはHFO-1234zeの単独冷媒又はHFO-1234yfもしくはHFO-1234zeを含む混合冷媒を使用する請求項1~12の何れか一項に記載の冷凍サイクル装置。
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JP2017512129A JP6463464B2 (ja) | 2015-04-15 | 2015-04-15 | 冷凍サイクル装置 |
PCT/JP2015/061603 WO2016166845A1 (ja) | 2015-04-15 | 2015-04-15 | 冷凍サイクル装置 |
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WO2018215425A1 (en) * | 2017-05-22 | 2018-11-29 | Swep International Ab | Refrigeration system |
WO2019207618A1 (ja) * | 2018-04-23 | 2019-10-31 | 三菱電機株式会社 | 冷凍サイクル装置および冷凍装置 |
JPWO2021166126A1 (ja) * | 2020-02-19 | 2021-08-26 |
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CN112303944A (zh) | 2019-07-31 | 2021-02-02 | 特灵国际有限公司 | 用于控制来自过冷却器的过热的系统和方法 |
EP4170262A1 (en) * | 2021-10-20 | 2023-04-26 | Thermo King Corporation | Heat pump, methods of operation and simulation |
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JP2006112708A (ja) * | 2004-10-14 | 2006-04-27 | Mitsubishi Electric Corp | 冷凍空調装置 |
JP2011179689A (ja) * | 2010-02-26 | 2011-09-15 | Hitachi Appliances Inc | 冷凍サイクル装置 |
JP2012207843A (ja) * | 2011-03-29 | 2012-10-25 | Fujitsu General Ltd | ヒートポンプ装置 |
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JP2006112708A (ja) * | 2004-10-14 | 2006-04-27 | Mitsubishi Electric Corp | 冷凍空調装置 |
JP2011179689A (ja) * | 2010-02-26 | 2011-09-15 | Hitachi Appliances Inc | 冷凍サイクル装置 |
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WO2018215425A1 (en) * | 2017-05-22 | 2018-11-29 | Swep International Ab | Refrigeration system |
US11480367B2 (en) | 2017-05-22 | 2022-10-25 | Swep International Ab | Refrigeration system |
WO2019207618A1 (ja) * | 2018-04-23 | 2019-10-31 | 三菱電機株式会社 | 冷凍サイクル装置および冷凍装置 |
CN112005062A (zh) * | 2018-04-23 | 2020-11-27 | 三菱电机株式会社 | 制冷循环装置以及制冷装置 |
JPWO2019207618A1 (ja) * | 2018-04-23 | 2021-02-12 | 三菱電機株式会社 | 冷凍サイクル装置および冷凍装置 |
CN112005062B (zh) * | 2018-04-23 | 2022-06-14 | 三菱电机株式会社 | 制冷循环装置以及制冷装置 |
JPWO2021166126A1 (ja) * | 2020-02-19 | 2021-08-26 |
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