WO2018079238A1 - 冷凍装置、冷凍システム - Google Patents
冷凍装置、冷凍システム Download PDFInfo
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- WO2018079238A1 WO2018079238A1 PCT/JP2017/036584 JP2017036584W WO2018079238A1 WO 2018079238 A1 WO2018079238 A1 WO 2018079238A1 JP 2017036584 W JP2017036584 W JP 2017036584W WO 2018079238 A1 WO2018079238 A1 WO 2018079238A1
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- Prior art keywords
- compressor
- liquid level
- refrigerant
- liquid
- controller
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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
- F25B49/022—Compressor control arrangements
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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
- 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
- F25B2400/13—Economisers
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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
- 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
- F25B2400/16—Receivers
- F25B2400/161—Receivers arranged in parallel
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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
- F25B2500/28—Means for preventing liquid refrigerant entering into 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
- F25B2600/00—Control issues
- F25B2600/02—Compressor control
- F25B2600/025—Compressor control by controlling speed
- F25B2600/0253—Compressor control by controlling speed with variable speed
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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
- F25B2600/05—Refrigerant levels
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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
- F25B2700/00—Sensing or detecting of parameters; Sensors therefor
- F25B2700/04—Refrigerant level
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B30/00—Energy efficient heating, ventilation or air conditioning [HVAC]
- Y02B30/70—Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating
Definitions
- the present invention relates to a refrigeration apparatus and a refrigeration system.
- This application claims priority on Japanese Patent Application No. 2016-213255 filed in Japan on October 31, 2016, the contents of which are incorporated herein by reference.
- a plurality of refrigeration equipment such as refrigerators, freezers, and showcases that store or display products such as foods and beverages in a refrigerated state or a frozen state are used.
- the plurality of refrigeration equipment receives supply of low-temperature and low-pressure liquid refrigerant from a condensing unit provided separately.
- Refrigeration equipment cools goods by supplying liquid refrigerant to an internal heat exchanger.
- the condensing unit is a so-called refrigeration device.
- the condensing unit includes a compressor, a cooler (gas cooler), an expansion valve, and a receiver (gas-liquid separator).
- the condensing unit compresses the refrigerant heated by the external refrigeration equipment with a compressor.
- the compressed refrigerant is cooled by a cooler and then expanded by an expansion valve to be a low-pressure and low-temperature refrigerant.
- the refrigerant that has entered the gas-liquid two-phase state through the expansion valve is separated into a gas phase (gas refrigerant) and a liquid phase (liquid refrigerant) by the receiver.
- the separated liquid refrigerant is supplied to an external refrigeration equipment.
- the separated gas refrigerant is sent to the compressor and compressed again.
- Refrigeration and refrigeration equipment to which liquid refrigerant is supplied from the condensing unit individually controls the cooling temperature for actually cooling the product according to the set temperature.
- refrigeration equipment is provided with the adjustment valve which adjusts the amount of refrigerant supplied to each heat exchanger, and the controller which controls the opening of an adjustment valve.
- the controller which controls the opening of an adjustment valve.
- the regulator is closed by the controller to reduce the amount of refrigerant supplied to the heat exchanger.
- the amount of refrigerant supplied from the condensing unit to the refrigeration unit varies by adjusting the amount of refrigerant with the refrigeration unit. For example, the liquid level of the liquid refrigerant in the receiver is increased by reducing the amount of refrigerant supplied from the condensing unit to the refrigeration equipment. As a result, the liquid refrigerant may be mixed in the gas refrigerant sent from the receiver to the compressor. Further, when the liquid refrigerant is mixed in the gas refrigerant, the mixed liquid refrigerant may be mixed with the lubricating oil in the compressor, and the lubricating performance may be deteriorated. Therefore, if a large amount of liquid refrigerant is sent to the compressor, there is a possibility that the compressor may be broken. For this reason, it is necessary to suppress that a liquid refrigerant is sent into a compressor.
- the above-described condensing unit is not provided as an integrated system together with a plurality of refrigeration / refrigeration equipment, and is often provided to customers as a single condensing unit separately from the refrigeration / refrigeration equipment. For this reason, in the condensing unit, it is difficult to perform control linked to the refrigeration / refrigeration equipment side, which may lead to an increase in cost.
- Patent Document 1 describes a configuration including a bypass pipe for gas injection for returning the gas refrigerant separated from the liquid refrigerant to the compressor, and a bypass valve provided in the bypass pipe.
- a bypass pipe for gas injection for returning the gas refrigerant separated from the liquid refrigerant to the compressor
- a bypass valve provided in the bypass pipe.
- the present invention provides a refrigeration apparatus and a refrigeration system capable of suppressing liquid refrigerant from being sent from a receiver to a compressor while suppressing an increase in temperature of a discharge gas from the compressor.
- the refrigeration apparatus includes a compressor that compresses a refrigerant, a heat exchanger that condenses the refrigerant compressed by the compressor, and an expansion that expands the refrigerant condensed by the heat exchanger.
- a valve a receiver that gas-liquid separates the refrigerant condensed by the expansion valve into a gas refrigerant and a liquid refrigerant, an injection circuit that sends the gas refrigerant separated by the receiver to the compressor, and the receiver
- a liquid level sensor that detects that the liquid level of the stored liquid refrigerant has reached a predetermined reference level and when the liquid level sensor detects that the liquid level has reached the reference level
- a controller for controlling to reduce the rotational speed of the compressor.
- the amount of refrigerant discharged from the compressor can be suppressed by reducing the rotation speed of the compressor.
- the increase in the liquid refrigerant in the receiver can be suppressed.
- it can suppress that a liquid refrigerant is sent with a gas refrigerant from a receiver to a compressor.
- the cooling gas sent from the receiver to the compressor can cool the discharge gas of the compressor to ensure reliability.
- the controller predetermines the rotational speed of the compressor with respect to a point in time when the liquid level sensor detects the liquid level at the reference level. When it is detected that a certain percentage has been reached, it may be controlled so as to decrease.
- the number of rotations of the compressor is reduced at a predetermined rate with respect to the detected time point at a time, so that the receiver can be easily controlled without adjusting the complex number of rotations by the controller.
- the liquid level inside can be lowered.
- the controller is configured such that when the predetermined set time elapses after the rotation speed of the compressor is reduced, When the sensor is in a state where the liquid level has reached the reference level, the rotational speed of the compressor may be further reduced.
- the controller is configured such that the pressure of the refrigerant supplied to the compressor is equal to or higher than a preset pressure target value.
- the rotational speed of the compressor may be decreased.
- Such a configuration can effectively lower the liquid level when the pressure of the refrigerant supplied to the compressor is high and liquid refrigerant tends to accumulate in the receiver.
- a lower liquid that detects a liquid level of the liquid refrigerant in the receiver below the liquid level sensor. An elapsed time from when the lower liquid level sensor detects the liquid level to when the liquid level sensor detects that the liquid level has reached the reference level. Based on the above, the rotational speed of the compressor may be reduced.
- the liquid level of the liquid refrigerant in the receiver can be grasped with high accuracy. Thereby, the raise of the liquid level in a receiver can be suppressed with high precision.
- the rate of decrease in the rotational speed of the compressor is increased, or the compressor May be stopped.
- a refrigeration system is the refrigeration apparatus according to any one of the first aspect to the ninth aspect, and a load connected to the refrigeration apparatus and exchanging heat with the liquid refrigerant supplied from the refrigeration apparatus.
- a loader having a side heat exchanger.
- the present invention it is possible to suppress the liquid refrigerant from being sent from the receiver to the compressor while suppressing a decrease in the cooling capacity.
- the refrigeration system 1 of the present embodiment includes a plurality of (three in the present embodiment) loaders 2 and a condensing unit (refrigeration apparatus) 3.
- the refrigeration system 1 uses CO 2 (carbon dioxide) as a refrigerant.
- the loader 2 is a refrigerator or a freezer that cools or refrigerates and stores the product, and a refrigeration device such as a showcase that cools or refrigerates and displays the product.
- the loader 2 receives supply of liquid refrigerant from the condensing unit 3.
- the loader 2 includes a heat exchanger (load-side heat exchanger) 21, a control valve (regulation valve) 22, a loader controller 23, and a temperature sensor 24.
- the heat exchanger 21 cools the product by exchanging heat with the liquid refrigerant supplied from the condensing unit 3.
- the heat exchanger 21 returns the heat-exchanged refrigerant to the condensing unit 3.
- the control valve 22 adjusts the cooling temperature of the product by adjusting the flow rate of the liquid refrigerant supplied from the condensing unit 3.
- the loader controller 23 controls the control valve 22 so that the internal cooling temperature approaches the set temperature based on the set temperature set from the outside and the cooling temperature at which the product is actually cooled detected by the temperature sensor 24. Adjust the opening.
- the condensing unit 3 includes a compressor 31, a gas cooler (heat exchanger) 32, an electronic expansion valve (expansion valve) 33, a receiver 34, a controller 100, an injection circuit 38, An oil separator 39 and a pressure sensor 40 are mainly provided.
- the compressor 31, gas cooler 32, electronic expansion valve 33, receiver 34, and oil separator 39 are connected by a refrigerant pipe 300.
- the compressor 31 compresses the refrigerant supplied from the loader 2 through the accumulator 35 by the suction pipe 302.
- the compressor 31 discharges a high-pressure and high-temperature refrigerant.
- CO 2 having a larger compression ratio than that of Freon or the like is used as the refrigerant.
- the compressor 31 is a two-stage compressor having a first-stage first compression section 31a and a second-stage second compression section 31b.
- the compressor 31 has a temperature sensor 37 that detects the temperature of the refrigerant liquid and oil in the first compression section 31 a of the compressor 31.
- the gas cooler 32 is supplied with a high-pressure and high-temperature refrigerant via an oil separator 39 after being discharged from the compressor 31.
- the gas cooler 32 exchanges heat between the supplied high-pressure and high-temperature refrigerant and air sent by a blower (not shown) to condense the refrigerant.
- a plurality of gas coolers 32 are provided in parallel.
- Each of the oil separators 39 collects lubricating oil contained in the refrigerant and returns it to the compressor 31.
- the electronic expansion valve 33 expands the refrigerant condensed by the gas cooler 32 to obtain a low-pressure and low-temperature refrigerant.
- the refrigerant expanded by the electronic expansion valve 33 is in a gas-liquid two-phase state.
- the receiver 34 gas-liquid separates the gas-liquid two-phase refrigerant expanded by the electronic expansion valve 33 into a gas refrigerant RG that is a gas-phase refrigerant and a liquid refrigerant RL that is a liquid-phase refrigerant.
- a plurality of receivers 34 are provided in parallel.
- the receiver 34 includes a tank 341 that stores a refrigerant in a gas-liquid phase state.
- a liquid supply pipe 301 and an injection circuit 38 are connected to the tank 341.
- the liquid refrigerant RL separated in the tank 341 is supplied to each external loader 2 through the liquid feeding pipe 301.
- the gas refrigerant RG separated in the tank 341 of the receiver 34 is sucked into the compressor 31 via the injection circuit 38.
- the injection circuit 38 is connected to the second compression unit 31 b of the compressor 31.
- the injection circuit 38 supplies the gas refrigerant RG in the tank 341 to the second compression unit 31b.
- the injection circuit 38 is provided with a solenoid valve 36.
- the opening degree of the solenoid valve 36 is adjusted according to the temperature of the refrigerant liquid and oil detected by the temperature sensor 37 under the control of the controller 100.
- By opening and closing the electromagnetic valve 36 the flow rate of the gas refrigerant RG sucked from the receiver 34 is adjusted.
- the liquid level L of the liquid refrigerant RL in the tank 341 varies according to the operating conditions on the plurality of loaders 2 side. That is, if the cooling temperature is lowered so as to reach the set temperature individually set on the loader 2 side, the amount of the liquid refrigerant RL used for the loader 2 increases. Therefore, the opening degree of the control valve 22 is increased, and the amount of the liquid refrigerant RL sent from the tank 341 to the loader 2 increases. As a result, the amount of the liquid refrigerant RL stored in the tank 341 decreases, and the liquid level L tends to decrease.
- the control valve 22 is closed or the opening degree is decreased, and the amount of the liquid refrigerant RL sent from the tank 341 to the loader 2 is reduced. As a result, the amount of the liquid refrigerant RL stored in the tank 341 increases, and the liquid level L in the tank 341 tends to increase.
- At least one receiver 34 has a liquid level sensor 342 in the tank 341.
- the liquid level sensor 342 outputs a predetermined signal to the controller 100 when the liquid refrigerant RL in the tank 341 reaches a predetermined reference level Ls.
- an optical level switch can be used as the liquid level sensor 342.
- the optical level switch includes a light emitting unit (not shown) that emits light toward the liquid level of the liquid refrigerant RL in the tank 341, and a light receiving unit (not shown) that receives reflected light on the liquid level of the light emitted from the light emitting unit. And comprising.
- the optical level switch when the liquid level reaches the position of the reference level Ls, the light emitted from the light emitting unit is not reflected by the light receiving unit, and the output signal changes. Thus, the optical level switch detects that the liquid level has reached the reference level Ls. Therefore, in this embodiment, if the liquid level L of the liquid refrigerant RL in the tank 341 does not reach the reference level Ls, the output signal from the liquid level sensor 342 to the controller 100 is OFF. Also. When the liquid level L reaches the reference level Ls, the output signal from the liquid level sensor 342 to the controller 100 is turned ON.
- the pressure sensor 40 measures the pressure of the refrigerant supplied to the compressor 31 via the loader 2.
- the pressure sensor 40 outputs the measurement result to the controller.
- the controller 100 controls the rotational speed of the compressor 31.
- the controller 100 controls the rotational speed of the compressor 31.
- the controller 100 determines the liquid level L of the liquid refrigerant RL in the tank 341 based on the output signal from the liquid level sensor 342.
- the controller 100 executes control for reducing the rotational speed of the compressor 31.
- the controller 100 according to the present embodiment performs control to reduce the rotational speed of the compressor 31 based on not only the liquid level L of the liquid refrigerant RL in the tank 341 but also the measurement result input from the pressure sensor 40. Execute.
- the controller 100 activates the compressor 31.
- the controller 100 operates the compressor 31 between a predetermined upper limit rotation speed and a lower limit rotation speed.
- the controller 100 increases the rotational speed of the compressor 31 when the refrigerant pressure input from the pressure sensor 40 is equal to or higher than a predetermined pressure target value Pa. Thereby, the pressure of the refrigerant
- the controller 100 stops the increase in the rotation speed of the compressor 31 and rotates it at a predetermined steady rotation speed Rs.
- the controller 100 stops the operation of the compressor 31 when the pressure of the refrigerant supplied to the compressor 31 becomes equal to or lower than a predetermined pressure lower limit value Pm. As the compressor 31 stops, the refrigerant pressure gradually increases with time.
- the controller 100 first determines whether or not the compressor 31 is operating (step S101). When it is determined that the compressor 31 is not operating, the controller 100 repeats the determination in step S101 every time a predetermined time has elapsed.
- step S102 the controller 100 determines whether or not the pressure of the refrigerant supplied to the compressor 31 is equal to or higher than a predetermined target pressure value (step S102). When the pressure of the supplied refrigerant is equal to or lower than the target pressure value, the process returns to step S101.
- step S102 when the pressure of the refrigerant supplied to the compressor 31 is equal to or higher than a predetermined target pressure value, the controller 100 then determines whether or not the output signal from the liquid level sensor 342 is ON.
- Step S103 it is also assumed that the liquid level L is fluctuating in the tank 341 and the output signal from the liquid level sensor 342 is temporarily ON. Therefore, when the controller 100 confirms that the state in which the output signal from the liquid level sensor 342 is ON for a predetermined time, for example, 1 second to 5 seconds, preferably about 2 seconds, It is preferable to determine that the output signal from the surface sensor 342 is ON.
- step S103 the controller 100 proceeds to the rotation control processing of the compressor 31 in step S104 and subsequent steps. To do.
- step S104 the controller 100 decreases the rotational speed of the compressor 31 (step S104).
- the rotational speed of the compressor 31 is decreased at a predetermined rate with respect to the rotational speed at the time when it is determined that the rotational speed is to be decreased.
- the predetermined ratio is, for example, 1% to 10%, preferably 3% to 8%, particularly preferably 5%.
- the controller 100 After reducing the rotational speed of the compressor 31, the controller 100 continues the operation at the rotational speed until the predetermined preset time Ts elapses (step S105).
- the set time Ts is, for example, 1 to 60 seconds, preferably 10 to 50 seconds, and particularly preferably about 30 seconds.
- the controller 100 checks the output signal from the liquid level sensor 342 again and determines whether or not the output signal remains ON (step S106). If the output signal from the liquid level sensor 342 is switched to OFF, the liquid level L in the tank 341 is lower than the reference level Ls. In this case, the controller 100 restores the number of rotations of the compressor 31.
- the liquid level L fluctuates in the tank 341 and the output signal from the liquid level sensor 342 is temporarily OFF. Therefore, when the output signal from the liquid level sensor 342 is OFF for a predetermined time, for example, 1 to 5 seconds, preferably about 2 seconds, the output signal from the liquid level sensor 342 is It is preferable to determine that the switch has been turned OFF.
- step S106 if the output signal from the liquid level sensor 342 remains ON in step S106, the liquid level L in the tank 341 remains above the reference level Ls. In this case, the process returns to step S104, and the rotational speed of the compressor 31 is further reduced by a predetermined rate.
- the controller 100 may decrease the rate at a rate different from the first time. In such a case, as the number of times of reducing the number of rotations of the compressor 31 is increased, the rate of decreasing the number of rotations may be increased or decreased stepwise.
- the controller 100 repeats the standby for the elapse of the set time Ts in step S105 and the determination of whether or not the liquid level sensor 342 in step S106 remains ON until the liquid level L falls below the reference level Ls. .
- the controller 100 repeatedly executes the processes in steps S101 to S106 as described above at predetermined time intervals during the operation of the compressor 31.
- the amount of the gas refrigerant RG supplied to the compressor 31 is reduced as in the case where the refrigerant supply amount of the gas refrigerant RG from the receiver 34 to the compressor 31 is reduced. It does not decrease. Therefore, the gas discharged from the compressor 31 can be cooled by the gas refrigerant RG, and the reliability of the compressor 31 can be ensured.
- the above configuration is particularly effective in the condensing unit 3 in which the compressor 31 compresses carbon dioxide having a large pressure ratio as a refrigerant, as in the present embodiment.
- the controller 100 detects that the liquid level L has reached the reference level Ls, the controller 100 reduces the rotational speed of the compressor 31 at a predetermined rate at a time. As a result, the liquid level L in the receiver 34 can be reduced with simple control without the controller 100 performing complicated adjustment of the rotational speed.
- the controller 100 determines the liquid level L again when a predetermined set time Ts has elapsed since the rotation speed of the compressor 31 is decreased, and further decreases the rotation speed of the compressor 31. .
- the controller 100 executes steps S103 and S104 to reduce the rotational speed of the compressor 31. Yes. Thereby, when the pressure of the refrigerant supplied from the loader 2 to the compressor 31 is high and the liquid refrigerant RL tends to accumulate in the receiver 34, the liquid level L can be effectively reduced.
- the controller 100 stops the compressor 31 when the pressure of the refrigerant measured by the pressure sensor 40 becomes equal to or lower than a preset pressure lower limit value Pm. Thereby, it is possible to suppress the operation of the compressor 31 from becoming unstable.
- the injection circuit 38 is configured to send the gas refrigerant RG to the second compression portion 31b of the compressor 31.
- the refrigerant compressed by the first compressor 31a and the gas refrigerant RG sent from the receiver 34 via the injection circuit 38 are supplied to the second compressor 31b.
- the pressure of the gas refrigerant RG discharged from the second compression unit 31b can be reduced.
- the receiver 34 is provided with the liquid level sensor 342 for detecting that the liquid level L of the liquid refrigerant RL has reached the reference level Ls.
- the receiver 34 is provided with a plurality of liquid level sensors. May be.
- a lower liquid level sensor 345 that detects the liquid level L of the liquid refrigerant RL in the tank 341 may be further provided below the liquid level sensor 342.
- the controller 100 detects the liquid level L of the liquid refrigerant RL with the lower liquid level sensor 345 and then detects that the liquid level L has reached the reference level Ls with the liquid level sensor 342.
- the rotational speed of the compressor 31 may be reduced based on the elapsed time until.
- the controller 100 may increase the rate at which the rotational speed of the compressor 31 is decreased. For example, in step S104 (see FIG. 5) of the above embodiment, the rotational speed of the compressor 31 is reduced by 5% with respect to the rotational speed at that time, but the elapsed time is shorter than the reference time. Sometimes, the controller 100 may reduce the rotational speed of the compressor 31 by, for example, 10%, which is twice as much.
- step S104 of the above embodiment the controller 100 reduces the rotational speed of the compressor 31 with respect to the rotational speed at that time, for example, by 5% for 30 seconds, and when the elapsed time is shorter than the reference time, the controller 100 May reduce the rotational speed of the compressor 31 by 10%, for example, in 30 seconds.
- controller 100 may stop the compressor 31 when the elapsed time is shorter than a predetermined reference time.
- the liquid level sensor 342 not only the liquid level sensor 342 but also the lower liquid level sensor 345 detects the liquid level L so that the liquid level L in the tank 341 is detected in two stages. Therefore, the liquid level L of the liquid refrigerant RL in the tank 341 can be grasped with high accuracy. Thereby, the rise in the liquid level in the tank 341 can be suppressed with high accuracy.
- the elapsed time is shorter than the predetermined reference time and the liquid level L of the liquid refrigerant RL in the tank 341 is changing sharply, the rate of decrease in the rotational speed of the compressor 31 is increased, or The compressor 31 is stopped.
- the liquid level L of the liquid refrigerant RL in the tank 341 is changing sharply, the liquid level L can be greatly lowered in response to the increase of the liquid level L.
- the receiver 34 is provided with the liquid level sensor 342 and the lower liquid level sensor 345.
- the present invention is not limited to this.
- a liquid level sensor for detecting the liquid level L may be provided.
- control by the controller 100 is not limited to the above-described example, and the processing order can be changed or a part of the processing can be omitted.
- the controller 100 when the liquid level sensor L 342 detects that the liquid level L has reached the reference level Ls, the controller 100 reduces the rotational speed of the compressor 31 at a predetermined rate.
- the degree to which the rotational speed of the compressor 31 is reduced may be more finely controlled according to the state of the refrigerant, the outside air temperature, and the like. Further, the controller 100 may stop the compressor 31 when the liquid level sensor 342 detects that the liquid level L has reached the reference level Ls.
- the refrigeration system 1 includes the plurality of loaders 2 and the condensing unit 3, but the number of loaders 2 is not limited at all.
- the plurality of loaders 2 do not have to be the same type, and a plurality of types of loaders 2 may be provided in a mixed manner.
- the refrigeration system 1 can be a unit having a loader 2 and a condensing unit 3 integrally.
- An example of such a unit is a vending machine for beverages.
- the refrigeration apparatus and the refrigeration system it is possible to suppress the liquid refrigerant from being sent from the receiver to the compressor while suppressing a decrease in the cooling capacity.
- Refrigeration system 2
- Loader 3 Condensing unit (refrigeration equipment) 21 Heat exchanger (load side heat exchanger) 22 Control valve (regulating valve) 23 Controller 24 Temperature sensor 31 Compressor 31a First compression part 31b Second compression part 32 Gas cooler (heat exchanger) 33 Electronic expansion valve (expansion valve) 34 Receiver 35 Accumulator 36 Solenoid valve 37 Temperature sensor 38 Injection circuit 39 Oil separator 100 Controller 300 Refrigerant pipe 301 Liquid feed pipe 302 Suction pipe 341 Tank 342 Liquid level sensor 345 Lower liquid level sensor L Liquid level Ls Reference level Pa Pressure target value Pm Pressure lower limit value RG Gas refrigerant RL Liquid refrigerant Rs Regular rotation speed Ts Setting time
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- Physics & Mathematics (AREA)
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- Devices That Are Associated With Refrigeration Equipment (AREA)
- Air Conditioning Control Device (AREA)
Abstract
Description
本願は、2016年10月31日に、日本に出願された特願2016-213255号について優先権を主張し、その内容をここに援用する。
なお、上記実施形態において、レシーバ34に、液冷媒RLの液面レベルLが基準レベルLsに到達したことを検出する液面センサ342を備えるようにしたが、複数の液面センサを備えるようにしてもよい。例えば、図6に示すように、液面センサ342の下方に、タンク341内の液冷媒RLの液面レベルLを検出する下部液面センサ345をさらに備えるようにしてもよい。
2 負荷器
3 コンデンシングユニット(冷凍装置)
21 熱交換器(負荷側熱交換器)
22 制御弁(調整弁)
23 コントローラ
24 温度センサ
31 圧縮機
31a 第一圧縮部
31b 第二圧縮部
32 ガスクーラ(熱交換器)
33 電子膨張弁(膨張弁)
34 レシーバ
35 アキュムレータ
36 電磁弁
37 温度センサ
38 インジェクション回路
39 オイルセパレータ
100 コントローラ
300 冷媒配管
301 送液管
302 吸入管
341 タンク
342 液面センサ
345 下部液面センサ
L 液面レベル
Ls 基準レベル
Pa 圧力目標値
Pm 圧力下限値
RG ガス冷媒
RL 液冷媒
Rs 定常回転数
Ts 設定時間
Claims (7)
- 冷媒を圧縮する圧縮機と、
前記圧縮機で圧縮された前記冷媒を凝縮させる熱交換器と、
前記熱交換器で凝縮された冷媒を膨張させる膨張弁と、
前記膨張弁で凝縮された前記冷媒をガス冷媒と液冷媒とに気液分離するレシーバと、
前記レシーバで分離された前記ガス冷媒を前記圧縮機に送り込むインジェクション回路と、
前記レシーバ内に貯留された前記液冷媒の液面レベルが予め定めた基準レベルに到達したことを検出する液面センサと、
前記液面センサで前記液面レベルが前記基準レベルに到達したことを検出した場合に、前記圧縮機の回転数を低下させるよう制御するコントローラと、を備える冷凍装置。 - 前記コントローラは、前記液面センサで前記液面レベルが前記基準レベルに到達したことを検出した場合に、検出した時点に対して前記圧縮機の回転数を予め定めた割合で低下させるよう制御する請求項1に記載の冷凍装置。
- 前記コントローラは、前記圧縮機の回転数を低下させてから予め定めた設定時間が経過した時点で、前記液面センサにおいて前記液面レベルが前記基準レベルに到達したままの状態であった場合、前記圧縮機の回転数をさらに低下させる請求項1又は2に記載の冷凍装置。
- 前記コントローラは、前記圧縮機に供給される前記冷媒の圧力が予め設定した圧力目標値以上であって、前記液面センサで前記液面レベルが前記基準レベルに到達したことを検出した場合に、前記圧縮機の回転数を低下させる請求項1から3の何れか一項に記載の冷凍装置。
- 前記液面センサの下方に、前記レシーバ内の前記液冷媒の液面レベルを検出する下部液面センサをさらに備え、
前記コントローラは、前記下部液面センサで前記液面レベルを検出してから、前記液面センサで前記液面レベルが前記基準レベルに到達したことを検出するまでの経過時間に基づき、前記圧縮機の回転数を低下させる請求項1から4の何れか一項に記載の冷凍装置。 - 前記経過時間が、予め定めた基準時間よりも短いときに、前記圧縮機の回転数の低下させる割合を増加、又は前記圧縮機を停止させる請求項5に記載の冷凍装置。
- 請求項1から6の何れか一項に記載の冷凍装置と、
前記冷凍装置に接続され、前記冷凍装置から供給される液冷媒と熱交換する負荷側熱交換器を有する負荷器と、を備える冷凍システム。
Priority Applications (2)
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AU2017350234A AU2017350234A1 (en) | 2016-10-31 | 2017-10-10 | Refrigeration device, refrigeration system |
EP17865277.2A EP3499147A4 (en) | 2016-10-31 | 2017-10-10 | REFRIGERATION DEVICE, REFRIGERATION SYSTEM |
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JP2016213255A JP2018071907A (ja) | 2016-10-31 | 2016-10-31 | 冷凍装置、冷凍システム |
JP2016-213255 | 2016-10-31 |
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WO2018079238A1 true WO2018079238A1 (ja) | 2018-05-03 |
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PCT/JP2017/036584 WO2018079238A1 (ja) | 2016-10-31 | 2017-10-10 | 冷凍装置、冷凍システム |
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EP (1) | EP3499147A4 (ja) |
JP (1) | JP2018071907A (ja) |
AU (1) | AU2017350234A1 (ja) |
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Cited By (2)
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US20210333026A1 (en) * | 2020-04-27 | 2021-10-28 | Emerson Electric Co. | Controls and related methods for mitigating liquid migration and/or floodback |
CN113970205A (zh) * | 2021-10-27 | 2022-01-25 | 珠海格力电器股份有限公司 | 一种储液罐的防液击控制系统 |
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JPH08285384A (ja) * | 1995-04-14 | 1996-11-01 | Nippondenso Co Ltd | 冷凍サイクル |
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US7891201B1 (en) * | 2006-09-29 | 2011-02-22 | Carrier Corporation | Refrigerant vapor compression system with flash tank receiver |
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2016
- 2016-10-31 JP JP2016213255A patent/JP2018071907A/ja active Pending
-
2017
- 2017-10-10 EP EP17865277.2A patent/EP3499147A4/en not_active Withdrawn
- 2017-10-10 WO PCT/JP2017/036584 patent/WO2018079238A1/ja unknown
- 2017-10-10 AU AU2017350234A patent/AU2017350234A1/en not_active Abandoned
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JPS60171362A (ja) * | 1984-02-14 | 1985-09-04 | 三菱電機株式会社 | 空気調和機 |
JPH08285384A (ja) * | 1995-04-14 | 1996-11-01 | Nippondenso Co Ltd | 冷凍サイクル |
JP2009522533A (ja) * | 2005-12-30 | 2009-06-11 | ジョンソン コントロールズ テクノロジー カンパニー | フラッシュタンクの冷媒制御 |
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Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20210333026A1 (en) * | 2020-04-27 | 2021-10-28 | Emerson Electric Co. | Controls and related methods for mitigating liquid migration and/or floodback |
US11768019B2 (en) * | 2020-04-27 | 2023-09-26 | Copeland Comfort Control Lp | Controls and related methods for mitigating liquid migration and/or floodback |
CN113970205A (zh) * | 2021-10-27 | 2022-01-25 | 珠海格力电器股份有限公司 | 一种储液罐的防液击控制系统 |
CN113970205B (zh) * | 2021-10-27 | 2023-03-14 | 珠海格力电器股份有限公司 | 一种储液罐的防液击控制系统 |
Also Published As
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EP3499147A1 (en) | 2019-06-19 |
JP2018071907A (ja) | 2018-05-10 |
EP3499147A4 (en) | 2019-09-18 |
AU2017350234A1 (en) | 2019-04-04 |
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