WO2018025363A1 - 冷凍装置 - Google Patents

冷凍装置 Download PDF

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Publication number
WO2018025363A1
WO2018025363A1 PCT/JP2016/072897 JP2016072897W WO2018025363A1 WO 2018025363 A1 WO2018025363 A1 WO 2018025363A1 JP 2016072897 W JP2016072897 W JP 2016072897W WO 2018025363 A1 WO2018025363 A1 WO 2018025363A1
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WO
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Prior art keywords
oil
compressor
refrigerant
temperature
amount
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PCT/JP2016/072897
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English (en)
French (fr)
Japanese (ja)
Inventor
篤史 岐部
Original Assignee
三菱電機株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Application filed by 三菱電機株式会社 filed Critical 三菱電機株式会社
Priority to JP2018531044A priority Critical patent/JPWO2018025363A1/ja
Priority to CN201680088153.3A priority patent/CN109564031A/zh
Priority to PCT/JP2016/072897 priority patent/WO2018025363A1/ja
Publication of WO2018025363A1 publication Critical patent/WO2018025363A1/ja

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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
    • 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
    • F25B43/00—Arrangements for separating or purifying gases or liquids; Arrangements for vaporising the residuum of liquid refrigerant, e.g. by heat
    • F25B43/02—Arrangements for separating or purifying gases or liquids; Arrangements for vaporising the residuum of liquid refrigerant, e.g. by heat for separating lubricants from the refrigerant

Definitions

  • the present invention relates to a refrigeration apparatus comprising a plurality of compressors connected in parallel to correct the unevenness of refrigeration oil in each compressor.
  • a refrigeration apparatus that includes a multi-outdoor unit that uses a combination of a plurality of outdoor units (also referred to as outdoor units) and corrects the refrigeration oil bias between the outdoor units.
  • a plurality of outdoor units including at least a compressor, a condenser, and an accumulator are connected in parallel with an indoor unit (also referred to as an indoor / outdoor unit) including a decompression unit and an evaporator.
  • a circuit is formed.
  • the refrigerant circuit is provided with an oil return pipe that returns the refrigeration oil stored in the accumulator to the compressor, an oil equalizing pipe that connects the accumulators, and an operation and oil equalization pipe of the compressor.
  • a control device that controls opening and closing of the electromagnetic valve (see, for example, FIG. 1 of Patent Document 1).
  • Patent Document 1 describes the oil leveling operation when three outdoor units are combined. For example, when the normal operation time is 1 hour and the oil equalizing operation time is 3 minutes, No. 1 outdoor unit 1a and No. 1 The outdoor unit 1b of No. 2 has an operating frequency of 90 Hz. No. 3 outdoor unit 1c is operated at an operating frequency of 45 Hz. In the oil leveling operation after 2 hours, no. 1 outdoor unit 1a and No. 1 No. 3 outdoor unit 1c has an operating frequency of 90 Hz. The second outdoor unit 1b is operated at an operating frequency of 45 Hz. Furthermore, in the oil leveling operation after 3 hours, No. 2 outdoor unit 1b and No. 2 outdoor unit 1b. No. 3 outdoor unit 1c has an operating frequency of 90 Hz. 1 outdoor unit 1a is operated at an operating frequency of 45 Hz. Then, after 4 hours, the operation returns to the beginning, and the oil leveling operation is repeated at the same operation frequency as in the first hour.
  • the control device operates a specific compressor at a lower operating frequency than the other compressors while opening all oil equalizing solenoid valves, and performs a low frequency operation every predetermined time.
  • the oil leveling operation is executed by changing the compressor and performing operation control for operating all the compressors at a low frequency at least once.
  • it adjusts so that the oil quantity of a compressor may turn into an appropriate oil quantity, always ensuring the minimum oil quantity in an accumulator.
  • Patent Document 1 always performs oil equalization operation (control) for adjusting the amount of oil in the gas-liquid separator that also serves as an oil tank every time the accumulated operation time of the compressor has elapsed for 1 hour. It is configured to do.
  • refrigeration equipment used in supermarket showcases, convenience stores, refrigerators, freezers, etc. usually performs product temperature management for 24 hours 365 days.
  • oil leveling control in which at least one compressor must be operated at a low frequency in a refrigeration apparatus having a plurality of outdoor units raises the internal temperature of the freezer. It will lead to things. Therefore, in the technique described in Patent Document 1, the refrigeration capacity is insufficient when oil equalization control is started, and the internal temperature may become unstable.
  • the present invention has been made to solve the above-described problems.
  • the operation such as the operation frequency of the compressor, the lower temperature in the shell of the compressor, the low pressure and temperature of the gas suction pipe, and the like such as the pressure and temperature of each part.
  • the purpose of the present invention is to provide a refrigeration apparatus that can stably maintain the internal temperature while ensuring the quality of the refrigeration apparatus by adjusting the oil return amount from the accumulator to each compressor according to the state. .
  • the refrigeration apparatus includes a refrigerant circuit in which at least a plurality of compressors, condensers, pressure reducing valves, evaporators, and accumulators connected in parallel are circularly connected in this order,
  • the upper part of the accumulator and each compressor are connected by a gas suction pipe for refrigerant gas suction, and the lower part of the accumulator and the lower part of each compressor are connected by an oil return pipe, respectively.
  • the electronic expansion valve controlled to vary the valve opening degree by an electric signal is provided.
  • the refrigeration apparatus is configured to control the electronic expansion valve of each oil return pipe based on the operating state such as the lower temperature in the shell of each compressor and the low pressure, the oil amount of each compressor is returned to the oil return It can be adjusted by control. Thereby, it has the effect that it can suppress that the internal temperature of the freezer which is a to-be-frozen object becomes unstable, and can aim at the reliability improvement of a compressor.
  • FIG. 4 is a graph showing an example of the relationship between the gas suction pipe temperature and the refrigerator oil viscosity when the low pressure saturation temperature is ⁇ 45 ° C. in the refrigeration apparatus. It is a circuit block diagram which shows roughly an example of the refrigerant circuit structure of the freezing apparatus in Embodiment 2 of this invention.
  • FIG. 1 shows an example of a refrigerant circuit configuration of a refrigeration apparatus according to an embodiment of the present invention.
  • This refrigeration apparatus 100 is used, for example, in supermarket showcases, convenience stores, refrigerators, freezers, etc., and is intended to improve reliability by correcting the bias of refrigeration oil in each compressor. is there.
  • the refrigeration apparatus 100 includes a plurality of (three in FIG. 1) outdoor units 1a, 1b, and 1c. These outdoor units 1 a, 1 b, and 1 c are connected in parallel to each other through the liquid pipe 23 and the gas pipe 24 to the indoor unit 20 having the expansion valve 21 (pressure reducing valve) and the evaporator 22.
  • the outdoor unit 1 will be generally described. The same applies to codes 2 and subsequent. 1 shows an example in which there are three outdoor units 1, but two or four or more outdoor units 1 may be used.
  • the outdoor unit 1 may be referred to as an outdoor unit
  • the indoor unit 20 may be referred to as an indoor unit.
  • the outdoor units 1a, 1b, and 1c include compressors 2a, 2b, and 2c, oil separators 3a, 3b, and 3c, condensers 4a, 4b, and 4c, and accumulators 5a, 5b, and 5c, respectively.
  • the condensers 4a, 4b, and 4c are connected to the liquid piping 23 that communicates with the expansion valve 21 of the indoor unit 20, and the distributors 25a and 25b are connected to the gas piping 24 that communicates with the evaporator 22 of the indoor unit 20.
  • the accumulators 5a, 5b, and 5c are connected via these.
  • the refrigerant circuit of the refrigeration apparatus 100 is formed by connecting the component devices by piping, and the refrigerant and the refrigeration oil contained in the refrigerant circulate in the refrigerant circuit to perform the refrigeration cycle operation.
  • the compressors 2a, 2b, and 2c compress the gas refrigerant and discharge it as a high-temperature and high-pressure refrigerant.
  • In-shell lower portions in the shells of the compressors 2a, 2b, and 2c are provided with in-shell temperature detecting means 31a, 31b, and 31c for detecting the temperature of the lower portion in each shell.
  • driving frequency detection means 32a, 32b, and 32c for detecting the operating frequency input to each motor M from an inverter device (not shown) are provided in the drive signal input portion of each motor M of the compressors 2a, 2b, and 2c. Each is deployed.
  • the oil separators 3a, 3b, 3c are connected to the discharge pipes 35a, 35b, 35c of the compressors 2a, 2b, 2c, and separate the refrigerating machine oil discharged together with the refrigerant from the compressors 2a, 2b, 2c from the refrigerant. It is.
  • the condensers 4a, 4b, and 4c are connected to refrigerant pipes 36a, 36b, and 36c from the oil separators 3a, 3b, and 3c, and are supplied from refrigerant from the compressors 2a, 2b, and 2c and, for example, a blower (not shown). Heat exchange with air.
  • the accumulators 5a, 5b, and 5c are installed on the suction side of the compressors 2a, 2b, and 2c, and also serve as an oil tank, and have a role of gas-liquid separation of the liquid refrigerant after the defrosting operation of the indoor unit 20. . That is, the accumulator 5 prevents the compressor from malfunctioning by suppressing liquid back to the compressor 2.
  • the electronic expansion valves 16a, 16b, and 16c are for controlling the amount of oil to the compressors 2a, 2b, and 2c, and keep the amount of refrigerating machine oil in the compressors 2a, 2b, and 2c at a specified amount. Is for.
  • the expansion valve 21 of the indoor unit 20 is configured to squeeze and expand the refrigerant circulating in the refrigerant circuit, and is configured with a valve whose opening degree can be variably controlled, such as an electronic expansion valve.
  • the evaporator 22 performs heat exchange between the refrigerant decompressed by the expansion valve 21 and the air supplied from the blower 22A.
  • the distributors 25a and 25b distribute the refrigerant and refrigerating machine oil flowing from the gas pipe 24 to the accumulators 5a, 5b and 5c.
  • the accumulators 5 a, 5 b, 5 c are connected to each other by an oil equalizing pipe 10 in order to correct a deviation in the amount of oil stored in each accumulator 5.
  • the tip portions 10a, 10b, 10c of the oil equalizing pipe 10 are inserted through the bottoms of the accumulators 5a, 5b, 5c, and the end inlets of the tip portions 10a, 10b, 10c are the accumulators 5a, 5b. , 5c are arranged at a predetermined height (same height) from the bottom surface.
  • the minimum amount of oil that can be always secured in the accumulators 5a, 5b, and 5c can be set.
  • the minimum amount of oil that can always be secured in one of the accumulators 5a, 5b, 5c is about 1L to 2L.
  • the gas refrigerant in the accumulators 5a, 5b, 5c (including the refrigerating machine oil that could not be separated) is sucked into the compressors 2a, 2b, 2c through the gas suction pipes 7a, 7b, 7c.
  • the gas suction pipes 7a, 7b, and 7c are formed in a U-shaped tubular shape at one end inserted into the accumulators 5a, 5b, and 5c, and return for returning oil or liquid refrigerant to the U-shaped pipe parts, respectively. It has holes 8a, 8b, 8c.
  • the U-shaped tube portion inserted into the accumulators 5a, 5b, 5c may be formed in a straight tube shape, and the straight tube portion may not include the return holes 8a, 8b, 8c. Good. Further, the return holes 8a, 8b, and 8c may be arranged side by side with a liquid return hole (not shown), or may serve as an oil return hole and a liquid return hole.
  • the gas suction pipes 7a, 7b, and 7c are respectively provided with low-pressure pressure detection means 33a, 33b, and 33c for detecting the low-pressure pressure and gas refrigerant temperature in each pipe, and gas refrigerant temperature detection means 34a, 34b, and 34c. Yes.
  • each of the oil return pipes 13a, 13b, 13c for returning the oil stored in the accumulators 5a, 5b, 5c to the compressors 2a, 2b, 2c penetrates the bottoms of the accumulators 5a, 5b, 5c, respectively.
  • the other end of each is connected to the shell lower part of compressor 2a, 2b, 2c.
  • electronic expansion valves 16a, 16b, and 16c whose valve opening degrees are variably controlled by electric signals for drive control from the control device 30 are respectively provided.
  • the oil separated and stored in the oil separators 3a, 3b, 3c is compressed through a gas suction pipe 7a, 7b, 7c via a capillary tube (not shown) or directly without a capillary tube. Oil is returned to 2a, 2b, 2c.
  • the control device 30 performs a normal operation for driving and controlling the compressors 2a, 2b, 2c and the like and an oil return operation for driving and controlling the valve opening degrees of the electronic expansion valves 16a, 16b, 16c of the oil return pipes 13a, 13b, 13c. Is.
  • the control device 30 is composed of, for example, a general-purpose microcomputer, and the microcomputer temporarily stores a calculation unit (not shown), detection data and calculation data, and stores control program data in advance.
  • a data bus (not shown) for inputting / outputting detection data and output drive data.
  • the arithmetic unit executes each function, which will be described in detail later, in accordance with the contents of the control program.
  • the calculation unit described above operates the frequency of the compressor 2, the fan rotation speed of the fan of the condenser 4, the valve opening of the expansion valve 21, and the evaporator 22
  • the low pressure values in the gas suction pipes 7a, 7b, 7c are detected by the low pressure detection means 33a, 33b, 33c.
  • the gas refrigerant temperature in the gas suction pipes 7a, 7b, 7c is detected by the gas refrigerant temperature detecting means 34a, 34b, 34c.
  • the lower temperature in the shell of the compressors 2a, 2b, 2c is detected by the shell temperature detecting means 31a, 31b, 31c.
  • the compressors 2a, 2b, and 2c are of a low-pressure shell type in which the inside of the shell is at a low pressure using a scroll or the like, and has a structure in which refrigeration oil is stored in the lower part of the shell of the compressor 2.
  • the number of rotations of the motor M that drives these compressors 2 is determined by a driving input signal having a driving frequency variably output from an inverter device (not shown).
  • the required amount of oil is the sum of the appropriate amount of oil in the compressors 2a, 2b, and 2c and the amount of oil present in each part of the refrigerant circuit. The amount is filled with an excess amount of oil. Excess oil is stored in the accumulators 5a, 5b, 5c.
  • the appropriate amount of oil in the compressors 2a, 2b, and 2c is an oil level that has a sufficient amount of oil that does not rapidly increase the oil take-out amount and does not exhaust the oil.
  • the control device 30 also detects the low pressure value detected by the low pressure detection means 33a, 33b, 33c, the gas refrigerant temperature detected by the gas refrigerant temperature detection means 34a, 34b, 34c, and the in-shell temperature detection means 31a, 31b.
  • 31c is used to estimate the amount of oil accumulated in the lower part of the shell of the compressor 2 based on the temperature in the lower part of the shell, and to perform adjustment control of the valve openings of the oil quantity control expansion valves 16a, 16b, 16c. To do. Detailed control will be described later.
  • the flow of the refrigerant is indicated by solid arrows in FIG.
  • the high-temperature and high-pressure gas refrigerant discharged from the compressors 2a, 2b, and 2c is condensed and liquefied by the condensers 4a, 4b, and 4c via the oil separators 3a, 3b, and 3c.
  • the liquefied refrigerant is reduced in pressure by the expansion valve 21 of the indoor unit 20 through the liquid pipe 23 to become a two-phase refrigerant, and is evaporated by the evaporator 22.
  • the gasified refrigerant then enters the accumulators 5a, 5b, 5c of the outdoor units 1a, 1b, 1c via the gas pipe 24 and the distributors 25a, 25b.
  • the refrigerant that has entered the accumulators 5a, 5b, and 5c and is further evaporated and gasified is sucked into the compressors 2a, 2b, and 2c through the gas suction pipes 7a, 7b, and 7c.
  • a refrigerant circuit in which the refrigerant circulates is formed, and the refrigeration cycle operation in which the refrigerant and the refrigeration oil circulate is repeatedly performed.
  • the oils that have not been separated by the oil separators 3a, 3b, 3c are the condensers 4a, 4b, 4c, the liquid pipe 23, the expansion valve 21, the evaporator 22, the gas pipe 24, the distributor 25a (some oil is distributed) Through the devices 25b) sequentially into the accumulators 5a, 5b, 5c.
  • the refrigerating machine oil and the gas refrigerant are separated, and the separated oil stays at the bottom of the accumulators 5a, 5b, 5c.
  • the refrigerating machine oil staying in the accumulators 5a, 5b, 5c is supplied from the oil return pipes 13a, 13b, 13c to the compressors 2a, 2b, 2c via the electronic expansion valves 16a, 16b, 16c. Excess oil in the refrigerant circuit is stored in accumulators 5a, 5b, and 5c in the low pressure portion.
  • Refrigerating machine oil that has not been separated by the oil separators 3a, 3b, 3c flows again into the outdoor units 1a, 1b, 1c after circulating through the refrigerant circuit.
  • oil is not evenly distributed to each outdoor unit 1, and the amount of oil returned is different for each outdoor unit 1.
  • the refrigeration apparatus 100 of the present embodiment is continuously operated for a long time, the amount of excess oil stored in the accumulators 5a, 5b, and 5c is different, and the accumulator 5 in which the oil is depleted appears.
  • the oil in the accumulator 5a is depleted
  • the oil in the compressor 2a is also depleted, which may cause damage to the compressor.
  • the oil equalizing pipe 10 is connected between the oil return pipe 13a from the accumulator 5a, the oil return pipe 13b from the accumulator 5b, and the oil return pipe 13c from the accumulator 5c. Further, the inlet positions (end positions) of the tip portions 10a, 10b, and 10c of the oil equalizing pipe 10 are arranged at predetermined height positions higher than the bottom surfaces in the accumulators 5a, 5b, and 5c. The inlet positions (end positions) of the tip portions 10a, 10b, 10c in the accumulators 5a, 5b, 5c are returned to the liquid refrigerant during the fan delay liquid back after the defrosting operation to prevent a failure due to a decrease in compressor oil concentration.
  • the control device 30 operates while controlling so as to adjust the valve openings of the electronic expansion valves 16a, 16b, 16c of the oil return pipes 13a, 13b, 13c.
  • the refrigeration apparatus 100 is used when the indoor temperature of the indoor unit 20 is +15 to ⁇ 55 ° C. and the evaporation temperature of the evaporator 22 is about +10 to ⁇ 65 ° C.
  • fins (not shown) of the heat exchanger section of the evaporator 22 used in a low temperature region are frosted and the amount of frost formation increases, the heat exchange capacity of the evaporator 22 decreases and the internal temperature rises.
  • the quality of the goods in the warehouse will deteriorate. Therefore, when used in a low temperature range, the defrosting operation for melting the frost of the evaporator 22 is performed several times a day.
  • the defrosting operation is set to enter several times within a day (the number of times is arbitrarily determined depending on the product in the warehouse and the temperature setting).
  • the details of the single defrosting operation are as follows. First, the operation of the refrigeration apparatus 100 is stopped (about 20 to 30 minutes). In the meantime, with the fan 22 ⁇ / b> A of the evaporator 22 stopped, the attached frost is melted by energizing a heater (not shown) provided inside the fin of the evaporator 22.
  • Methods for melting frost include not only a heater but also a method of flowing a high-temperature and high-pressure refrigerant gas and a method of simply stopping the fan 22A of the evaporator 22.
  • the refrigerant circuit of the refrigeration apparatus 100 is in operation, and heat exchange is not sufficient on the evaporator 22 side.
  • the vaporization of the refrigerant cannot be sufficiently performed on the evaporator 22 side, and the two-phase refrigerant remains.
  • these two-phase refrigerants particularly the liquid refrigerant is about 10% to 40% of oil (in other words, the oil staying in the gas pipe 24) that could not be separated by the oil separators 3a, 3b, 3c. It will return all to the circuit. All the accumulated oil cannot be evenly distributed to the outdoor units 1a, 1b, and 1c in the transient operation of recooling the internal temperature that has risen within the time of melting and frost melting. It is possible.
  • an oil amount is secured for each of the outdoor units 1a, 1b, 1c at the positions (end positions) of the front end portions 10a, 10b, 10c in the accumulators 5a, 5b, 5c, and the compressors 2a, 2b, 2c Prevents malfunctions due to lower oil concentration. Further, in order to prevent the outdoor units 1a, 1b, and 1c that are not limited to oil exhaustion and excessive oil, an oil equalizing pipe 10 is provided, and the accumulators 5a, 5b, and 5c are provided regardless of whether the refrigeration apparatus 100 is operated or stopped. The amount of oil inside is kept uniform. The above is the outline of the internal configuration of the fan delay liquid bag and the accumulator 5.
  • the control device 30 detects the low pressure value detected by the low pressure detection means 33a, 33b, 33c of the gas suction pipes 7a, 7b, 7c, and the gas refrigerant temperature detection means 34a of the gas suction pipes 7a, 7b, 7c, Based on the gas refrigerant temperature value detected by 34b, 34c and the shell inner temperature detection means 31a, 31b, 31c of the compressors 2a, 2b, 2c, the inside of each compressor 2 is By controlling the valve opening degree of the electronic expansion valves 16a, 16b, and 16c between the oil return pipes 13a, 13b, and 13c and the compressors 2a, 2b, and 2c so that the optimum oil amount is obtained, Try to stabilize the internal temperature.
  • FIG. 2 shows an example of the amount of refrigeration oil discharged from the compressor with respect to the amount of refrigeration oil inside the compressor.
  • the amount of oil inside the shell of the compressor 2 increases, the amount of oil taken into the compression unit increases, and thus the amount of refrigeration oil discharged increases.
  • the motor M since the motor M is in the shell of the compressor 2, when the refrigeration oil begins to soak in the motor M, the amount of refrigeration oil discharged increases in a straight line. This is because there is almost no refrigerant gas inside the shell of the compressor 2 and it is filled with refrigerating machine oil. The higher the operating frequency, the greater the force that is taken into the compressor of the compressor 2, so that it is discharged. Increases the amount of refrigerating machine oil.
  • the compressor internal oil amount exceeds about 1.8 L, the amount of refrigerating machine oil discharged is significantly increased. Therefore, it is necessary to adjust the oil amount so that the amount of refrigeration oil in the compressor 2 is about 1.5 L to 1.8 L.
  • the amount of refrigerating machine oil inside the compressor 2 is 1.5 L or less, if the amount of refrigerating machine oil discharged during the transient operation of the compressor 2 increases, the followability of the electronic expansion valves 16a, 16b, 16c deteriorates, and the compressor 2 may lead to oil depletion. That is, the amount of oil inside the compressor 2 is preferably about 1.5 to 1.8 L which is the optimum amount of oil.
  • FIG. 3 shows an example of the lower temperature in the compressor shell with respect to the amount of refrigeration oil inside the compressor.
  • the amount of oil inside the compressor 2 increases, so that the lower temperature inside the shell of the compressor increases.
  • the motor M is inside the shell of the compressor 2
  • the refrigeration oil begins to soak in the motor M
  • the temperature in the lower part of the shell of the compressor 2 increases to the right. This is the same as in FIG. 2, but there is almost no refrigerant gas inside the compressor 2 and it is filled with refrigeration oil.
  • the effect of heat generated by the motor M is also added, and the lower temperature inside the shell of the compressor 2 is increased. Get higher.
  • the lower temperature in the shell of the compressor 2 is detected by the shell temperature detecting means 31a, 31b, 31c provided in the lower part in the shell.
  • the control device 30 temporarily stops the operation of the refrigeration device 100 and issues an abnormality alarm to the outside of the device.
  • the temperature in the lower part of the shell of the compressor 2 is 75 ° C. or lower, protection control is resumed to restart the operation.
  • the input (kW) consumed by the heat generation of the motor M is an extra input, which leads to deterioration of COP.
  • the compressor 2 at the optimum oil amount is used.
  • the lower temperature in the shell is about 70 ° C. ⁇ 5 degrees.
  • the lower temperature in the shell of the compressor 2 depends on the low pressure saturation temperature of ⁇ 5 to ⁇ 45 ° C. and the outside air temperature of ⁇ 15 to 43 ° C., and the gas intake pipe temperature depends on the degree of opening of the expansion valve 21 in the indoor unit 20. There are various.
  • the state of the lower temperature in the shell and the amount of the refrigerating machine oil in the compressor 2 shell in each operation state is grasped in advance by the control device 30.
  • the temperature difference between the gas suction pipe temperature and the low pressure saturation temperature is ensured to be 10K or more so that the liquid suction of the compressor 2 is not performed.
  • suction superheat the temperature difference between the gas suction pipe temperature and the low pressure saturation temperature. Therefore, in the control device 30, the low pressure values detected by the low pressure detection means 33a, 33b, 33c in the gas suction pipes 7a, 7b, 7c and the gas refrigerant temperature detected by the gas refrigerant temperature detection means 34a, 34b, 34c.
  • the inside of the shell of the compressor 2 The amount of refrigeration oil can be estimated.
  • FIG. 4 shows an example of the refrigerator oil viscosity with respect to the gas suction pipe temperature when the low pressure saturation temperature is ⁇ 45 ° C.
  • the gas intake pipe temperature varies depending on the opening state of the expansion valve 21 in the indoor unit 20, and corresponds to a portion that cannot be controlled by the outdoor units 1a, 1b, and 1c.
  • the viscosity of the refrigerating machine oil generally increases as the low-pressure saturation temperature of the refrigerant is lower and as the gas suction pipe temperature is lower, because the fluidity of the oil is lost.
  • the suction superheat without liquid back is about 10K, the viscosity of the oil is highest and the movement of the oil is reduced.
  • the control device 30 is made to know in advance the oil viscosity, gas suction pipe (inner diameter, length), and return oil pipe (inner diameter, length) of the refrigerating machine oil.
  • the low pressure values detected by the low pressure detection means 33a, 33b, 33c of the gas suction pipes 7a, 7b, 7c and the gas refrigerant temperature detection means 34a, 34b of the gas suction pipes 7a, 7b, 7c Since the amount of movement of the refrigerating machine oil amount can be estimated from information input in advance by using the gas refrigerant temperature detected at 34c, the operation of the electronic expansion valve 16 is controlled by controlling the valve opening degree. The amount of refrigerating machine oil movement can be adjusted according to the situation.
  • the low pressure saturation temperature is a value obtained by converting a low pressure value by the low pressure detecting means 33a, 33b, 33c of the gas suction pipes 7a, 7b, 7c into a saturation temperature.
  • the operating frequency of the compressor 2 is a value for controlling the operation of the inverter device by the control device 30, and is a detected value detected by the operating frequency detecting means 32a, 32b, 32c.
  • the gas suction pipe temperature is a gas refrigerant temperature value detected by the gas refrigerant temperature detection means 34a, 34b, 34c of the gas suction pipes 7a, 7b, 7c.
  • the refrigerant circulation amount W is a value calculated based on the operating frequency of the compressor 2, the gas suction pipe temperature, the low pressure saturation temperature, and the displacement amount of the compressor 2 (corresponding to the motor rotation speed). is there. By knowing in advance the amount of displacement of the compressor 2 and the density of the refrigerant used in the control device 30, the refrigerant circulation amount W can be estimated from the operating state. As described above (an example of FIG. 3), the amount of refrigerant oil in the shell of the compressor 2 is low pressure value and gas refrigerant temperature detecting means by the low pressure detecting means 33a, 33b, 33c of the gas suction pipes 7a, 7b, 7c.
  • the control device 30 can estimate the amount of refrigerating machine oil Y discharged from the compressor 2 by the operating frequency of the compressor 2 and the amount of refrigerating machine oil discharged from the compressor 2 as described above (an example of FIG. 2).
  • the control device 30 can estimate the amount of the refrigerating machine oil Y discharged from the compressor 2 in advance from the operating state.
  • the oil separator separation efficiency Z is a value determined by the performance of the oil separators 3a, 3b, 3c mounted on the product in the refrigeration apparatus 100.
  • control device 30 grasps the refrigeration oil amount Z of the oil separator 3 in advance, it is possible to estimate the refrigeration oil amount Y discharged from the operating state. Since the amount of refrigerating machine oil moving to the indoor unit 20 side can be calculated by the calculation formula described in Table 1, it can be calculated by the control device 30 according to the change in the operating state.
  • the control of the electronic expansion valve 16 is performed by estimating the operating situation from the following two calculations. “First”: calculation of refrigerating machine oil moving through the oil return pipes 10a, 10b, 10c;
  • the refrigerating machine oil moving through the oil return pipes 10a, 10b, 10c is the oil viscosity of the refrigerating machine oil, the gas suction pipe 7 (inner diameter, length), and the oil return pipe 13 (inner diameter, length) as described above (an example of FIG. 4). It depends on the situation.
  • the control device 30 grasps the oil viscosity of the refrigerating machine oil, the gas suction pipe 7 (inner diameter, length), and the oil return pipe 13 (inner diameter, length) in advance, so that the amount of oil movement according to the operating situation. Can be calculated. “Second”: Calculation of the amount of refrigerating machine oil moving to the indoor unit 20 side (value calculated by the calculation formula of Table 1); Therefore, the amount of refrigerating machine oil that moves through the oil return pipe 13 calculated from the viscosity of the oil and the amount of refrigerating machine oil that moves toward the indoor unit 20 calculated from the discharged refrigerating machine oil amount of the compressor 2 are equal.
  • the valve opening degree of the expansion valve 16 is determined in advance.
  • the control device 30 can detect the operation data and calculate and output the required valve opening of the electronic expansion valve 16 every 10 seconds so that the optimum oil amount can be adjusted according to the operation of the compressor 2. Become.
  • the valve opening degree of the electronic expansion valve 16 under the refrigeration conditions shown in Table 1 is 10 pulses.
  • the separation efficiency of the oil separator 3 is good at 95% in the region where the refrigerant circulation amount is small such as the refrigeration conditions, so that most of the amount of refrigerating machine oil discharged from the compressor 2 is the gas suction pipes 7a, 7b, Since the oil is returned to the 7c side, there is almost no decrease in the amount of refrigerating machine oil inside the shell of the compressor 2, and the valve opening degree of the electronic expansion valve 16 is 10 pulses, which is predominantly close to the closed state. is there. On the contrary, the valve opening of the electronic expansion valve 16 under refrigeration conditions is 400 pulses.
  • the separation efficiency of the oil separator 3 is 70%, which is lower than the refrigeration conditions, in a region where the refrigerant circulation amount is large such as refrigeration conditions, and only about 70% of the amount of refrigerating machine oil discharged from the compressor 2 is gas. Since the oil is not returned to the suction pipes 7a, 7b, and 7c, the amount of the refrigerating machine oil in the shell of the compressor 2 is reduced, and the valve opening degree of the electronic expansion valve 16 is 400 pulses. .
  • the amount of refrigerating machine oil inside the shell of the compressor 2 can always be kept at the optimum oil amount.
  • the opening degree of the expansion valve 21 in the indoor unit 20 is set to be large or the suction superheat generated when the followability of the expansion valve 21 is poor is less than 10K (in the liquid back state) Will be described.
  • each accumulator 5 performs gas-liquid separation.
  • the liquid refrigerant reaches a specified amount or more, the liquid refrigerant overflows and enters each compressor 2, and the oil concentration in the compressor 2 decreases. There is a risk of failure.
  • the liquid refrigerant (liquid back amount) entering the compressor 2 when the liquid refrigerant (liquid back amount) entering the compressor 2 is small, the liquid refrigerant returns to the compressor 2 of one outdoor unit 1.
  • the amount of liquid refrigerant (liquid back amount) entering the compressor 2 is large, the liquid refrigerant returns to any two of the outdoor units 1 or the compressors 2a, 2b, 2c of all the outdoor units 1a, 1b, 1c. It becomes. Since the suction superheat of each outdoor unit 1 can be detected at any time by the control device 30 and the state can be grasped, if it is determined that any of the outdoor units 1 is in the liquid back state, the outdoor unit 1 that has liquid backed The valve opening of the electronic expansion valve 16 is fully closed.
  • the refrigeration apparatus 100 includes a refrigerant circuit having a plurality of parallel-connected compressors 2 and accumulators 5, and an electronic expansion valve is provided in each oil return pipe 13 that connects each accumulator 5 and each compressor 2. 16 is provided, and the opening degree of each electronic expansion valve 16 is controlled based on the operating state of the compressor 2 detected by each detecting means. Therefore, the amount of refrigerating machine oil and the oil return pipe 13 inside the compressor 2 are controlled. The required oil supply from Thereby, since the valve opening degree of the electronic expansion valve 16 can be adjusted according to the operation state, it is possible to suppress the in-chamber temperature of the freezer from becoming unstable, and to improve the reliability of the compressor 2. be able to.
  • the refrigeration apparatus 100 includes a single outdoor unit 1 that includes an accumulator 5, a compressor 2, an oil separator 3, a condenser 4, a gas suction pipe 7, an oil return pipe 13, and an electronic expansion valve 16. Since the system 1 has three systems in parallel, even if a system component of any one of the outdoor units 1 breaks down, there is an effect that the operation can be continued by the other remaining outdoor units 1 and 1. As a result, unlike the case where one accumulator and one condenser are provided, there is no problem that the entire refrigeration apparatus must be stopped when the accumulator or condenser fails.
  • FIG. 1 the description has been made with the refrigerant circuit of FIG. 1 configured by a plurality of outdoor units 1a, 1b, and 1c.
  • the same effect can be obtained by the configuration of the refrigerant circuit in the refrigeration apparatus 100A illustrated in FIG. Can be obtained.
  • the difference between the configuration of FIG. 5 and the configuration of FIG. 1 will be described below.
  • components having the same reference numerals in the refrigerant circuit components described in FIG. 1 are the same in FIG. 5 and may not be described.
  • the configuration of FIG. 1 is a form using a plurality of accumulators and condensers, but the configuration of FIG. 5 is a configuration using one accumulator 5A and one condenser 4A.
  • each of the accumulators 5a, 5b, 5c is configured as an oil tank.
  • the amount of refrigerating machine oil necessary for all of the compressors 2a, 2b, 2c is one accumulator. It is stored in 5A. As a result, there is no variation in the mounting angle of the distributor, and the deviation of the liquid refrigerant during the liquid back is reduced.
  • the low pressure detected by the low pressure detection means 33a, 33b, 33c in the gas suction pipes 7a, 7b, 7c similarly to the control device 30 of FIG. 1, the low pressure detected by the low pressure detection means 33a, 33b, 33c in the gas suction pipes 7a, 7b, 7c. Values, gas refrigerant temperature values detected by the gas refrigerant temperature detecting means 34a, 34b, 34c, and shell lower temperature values detected by the shell temperature detecting means 31a, 31b, 31c in the compressors 2a, 2b, 2c, etc.
  • the electronic expansion valves 16a, 16b, 16c of the oil return pipes 13a, 13b, 13c are respectively controlled.
  • the control contents of the electronic expansion valves 16a, 16b, and 16c by the control device 30A are the same as those described with reference to FIG. That is, in the refrigeration apparatus 100A, the valve opening degree of each of the electronic expansion valves 16a, 16b, 16c is controlled based on the operation state of the refrigerant circuit detected by each detection means, so the compressors 2a, 2b , 2c and the required amount of oil supplied from the oil return pipes 13a, 13b, 13c. Thereby, since the valve opening degree of electronic expansion valve 16a, 16b, 16c can be adjusted according to an operating condition, it can control that the temperature in a freezer becomes unstable, and the reliability of compressor 2 is provided. It is possible to improve the performance.
  • the compressor 2, the oil separator 3, the gas suction pipe 7 and the oil return pipe 13 are plural, whereas the accumulator 5A and the condenser 4A are each one,
  • the circuit configuration of the circuit is very simple, and there is an effect that it can be provided at low cost.
  • the same effect can be obtained as long as the refrigerant and the oil are compatible. That is, as the refrigerant, HFC refrigerant, HFC refrigerant mixed refrigerant, HC refrigerant, HC refrigerant mixed refrigerant, HFC refrigerant and HC refrigerant mixed refrigerant, or natural refrigerants such as carbon dioxide and water are used. obtain.
  • the refrigerating machine oil an oil compatible with the above-described refrigerants, for example, an ester oil in the case of an HFC refrigerant, a mineral oil in the case of an HC refrigerant, a PAG oil or the like in the case of carbon dioxide can be used. Needless to say, the same effect can be obtained even when these are used.

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2023209969A1 (ja) * 2022-04-28 2023-11-02 三菱電機株式会社 空気調和装置

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH102626A (ja) * 1996-06-12 1998-01-06 Mitsubishi Heavy Ind Ltd 空気調和装置
JP2003279175A (ja) * 2002-03-22 2003-10-02 Mitsubishi Electric Corp 冷凍空調装置
JP2004353904A (ja) * 2003-05-28 2004-12-16 Sanyo Electric Co Ltd アキュームレータおよび空気調和装置
JP2007285699A (ja) * 2003-10-20 2007-11-01 Lg Electronics Inc 空調機の液冷媒蓄積防止装置および方法
WO2010113395A1 (ja) * 2009-03-31 2010-10-07 三菱電機株式会社 冷凍装置

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4176679B2 (ja) * 2004-06-14 2008-11-05 三菱重工業株式会社 空気調和装置の制御方法及びその制御装置、並びに空気調和装置

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH102626A (ja) * 1996-06-12 1998-01-06 Mitsubishi Heavy Ind Ltd 空気調和装置
JP2003279175A (ja) * 2002-03-22 2003-10-02 Mitsubishi Electric Corp 冷凍空調装置
JP2004353904A (ja) * 2003-05-28 2004-12-16 Sanyo Electric Co Ltd アキュームレータおよび空気調和装置
JP2007285699A (ja) * 2003-10-20 2007-11-01 Lg Electronics Inc 空調機の液冷媒蓄積防止装置および方法
WO2010113395A1 (ja) * 2009-03-31 2010-10-07 三菱電機株式会社 冷凍装置

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2023209969A1 (ja) * 2022-04-28 2023-11-02 三菱電機株式会社 空気調和装置

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