WO2024047832A1 - 冷凍サイクル装置および空気調和装置 - Google Patents

冷凍サイクル装置および空気調和装置 Download PDF

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Publication number
WO2024047832A1
WO2024047832A1 PCT/JP2022/032912 JP2022032912W WO2024047832A1 WO 2024047832 A1 WO2024047832 A1 WO 2024047832A1 JP 2022032912 W JP2022032912 W JP 2022032912W WO 2024047832 A1 WO2024047832 A1 WO 2024047832A1
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Prior art keywords
refrigerant
temperature
heat exchanger
refrigeration cycle
dry protection
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PCT/JP2022/032912
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English (en)
French (fr)
Japanese (ja)
Inventor
瑞朗 酒井
竜也 峯岡
佳浩 楊
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Mitsubishi Electric Corp
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Mitsubishi Electric Corp
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Priority to JP2024543723A priority Critical patent/JP7724979B2/ja
Priority to PCT/JP2022/032912 priority patent/WO2024047832A1/ja
Publication of WO2024047832A1 publication Critical patent/WO2024047832A1/ja
Anticipated expiration legal-status Critical
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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

Definitions

  • This technology relates to refrigeration cycle devices and air conditioners.
  • the present invention relates to dry protection control in a refrigerant circuit using a refrigerant having a temperature gradient.
  • a refrigeration cycle device such as an air conditioner circulates a refrigerant filled in a refrigerant circuit to exchange heat with a fluid such as air or water, thereby heating or cooling the fluid.
  • GWP global warming potential
  • Refrigerants with a high global warming potential cause global warming when released into the atmosphere.
  • refrigerants used in refrigeration cycle devices to shift to refrigerants with lower global warming coefficients due to increased environmental awareness. Therefore, in recent years, a non-azeotropic mixed refrigerant, which is a mixture of multiple types of refrigerants with different boiling points, has been used as a refrigerant with a low global warming potential.
  • control device that controls the equipment of the refrigeration cycle device corrects the evaporation temperature by using physical quantities such as the temperature detected by a detection device such as a sensor, and calculations from the physical quantities (for example, see Patent Document 1). .
  • dry protection control such as protection of the compressor or determination of insufficient amount of refrigerant is performed based on the dry state of the refrigerant.
  • a refrigerant circuit using a refrigerant having a temperature gradient, such as a non-azeotropic mixed refrigerant the temperature of the refrigerant differs during the evaporation process, so there is a possibility that appropriate correction may not be performed. For this reason, the overheating state of the refrigerant during the evaporation process cannot be accurately determined, and there is a possibility that dry protection control cannot be performed accurately.
  • a refrigeration cycle device has a refrigerant circuit configured by connecting a compressor, a condenser, an expansion valve, and an evaporator with piping, and circulates a mixed refrigerant having a temperature gradient.
  • a two-phase pipe temperature sensor detects the temperature of the mixed refrigerant passing through the heat exchanger, and the two-phase pipe temperature sensor corrects the heat exchanger passing temperature, and performs dry protection based on the corrected temperature. and a control device that performs dry protection control based on the determination.
  • the air conditioner according to this disclosure performs heating and cooling of a target space using the above-mentioned refrigeration cycle device.
  • the control device corrects the heat exchanger passing temperature detected by the two-phase pipe temperature sensor, and determines whether to perform dry protection control based on the corrected temperature. Then, dry protection control is performed based on the judgment. Therefore, it is possible to determine whether or not to perform dry protection control after correcting the heat exchanger passing temperature to a more accurate temperature. Therefore, the refrigeration cycle device can perform dry protection control based on a more accurate dry state.
  • FIG. 1 is a diagram showing the configuration of a refrigeration cycle device according to Embodiment 1.
  • FIG. 1 is a diagram showing a schematic configuration of an example of a heat exchanger according to Embodiment 1.
  • FIG. 3 is a diagram illustrating the configuration of a control device 400 in the air conditioner 1 according to the first embodiment. It is a pH diagram in a refrigeration cycle device.
  • FIG. 3 is a diagram showing the relationship between pressure and temperature in the evaporation process of a non-azeotropic mixed refrigerant when the pressure in the evaporator is constant in the refrigeration cycle device according to the first embodiment.
  • FIG. 3 is a diagram showing the relationship between pressure and temperature in the evaporation process of a non-azeotropic mixed refrigerant when a pressure difference occurs in the evaporator in the refrigeration cycle device according to the first embodiment.
  • FIG. 3 is a diagram showing a change in refrigerant temperature over time when the amount of refrigerant circulation is small in the outdoor heat exchanger 230 of the air conditioner 1 according to the first embodiment.
  • FIG. 6 is a diagram showing a temporal change in refrigerant temperature when the amount of refrigerant circulation is large in the outdoor heat exchanger 230 of the air conditioner 1 according to the first embodiment.
  • FIG. 7 is a diagram illustrating dry protection control processing of the refrigeration cycle device according to the second embodiment.
  • 3 is a diagram showing the configuration of a control device 400 according to Embodiment 3.
  • FIG. FIG. 4 is a diagram showing the configuration of a control device 400 according to a fourth embodiment.
  • FIG. 1 is a diagram showing the configuration of a refrigeration cycle device according to Embodiment 1.
  • the air conditioner 1 according to the first embodiment includes an outdoor unit 200, an indoor unit 100, and two refrigerant pipes 300.
  • the compressor 210, four-way valve 220, outdoor heat exchanger 230, and expansion valve 240 of the outdoor unit 200 are connected to the indoor heat exchanger 110 of the indoor unit 100 by a refrigerant pipe 300, and the refrigerant is circulated.
  • the indoor unit 100 may include the expansion valve 240.
  • the air conditioner 1 according to the first embodiment is configured such that one outdoor unit 200 and one indoor unit 100 are connected by piping. However, the number of connected devices is not limited to this.
  • the air conditioner 1 uses a non-azeotropic mixed refrigerant as the refrigerant that circulates within the refrigerant circuit.
  • a non-azeotropic mixed refrigerant is a refrigerant that is a mixture of multiple component refrigerants and whose composition changes when it evaporates and condenses.
  • a non-azeotropic mixed refrigerant is in a gas-liquid two-phase state under the same pressure and does not settle at a constant temperature as the composition changes. For example, in the evaporation process under the same pressure, the temperature of the non-azeotropic mixed refrigerant at the end of evaporation is higher than the refrigerant temperature at the start of evaporation.
  • the refrigerant temperature of the non-azeotropic mixed refrigerant at the end of condensation is lower than the refrigerant temperature at the start of condensation.
  • the temperature difference between the start and end of evaporation or condensation is the temperature gradient.
  • the non-azeotropic mixed refrigerant used in the air conditioner 1 in the first embodiment is R454B, which is a mixture of R32 refrigerant and R1234yf refrigerant, which are HFC (hydrofluorocarbon) refrigerants, at a ratio of 68.1:31.9. It shall be a refrigerant.
  • Outdoor unit 200 in Embodiment 1 includes a compressor 210, a four-way valve 220, and an outdoor heat exchanger 230 as devices constituting a refrigerant circuit. Furthermore, the outdoor unit 200 includes an outdoor blower 250 and a control device 400.
  • the compressor 210 compresses and discharges the sucked refrigerant.
  • Compressor 210 is, for example, a scroll compressor, a rotary compressor, a vane compressor, or the like.
  • the compressor 210 can change the circulating amount of refrigerant discharged by the compressor 210 by arbitrarily changing the driving frequency using, for example, an inverter circuit.
  • the four-way valve 220 serving as a flow path switching device is, for example, a valve that switches the flow of refrigerant between cooling operation and heating operation.
  • the four-way valve 220 connects the discharge side of the compressor 210 and the indoor heat exchanger 110 and connects the suction side of the compressor 210 and the outdoor heat exchanger 230 when heating operation is performed. Furthermore, the four-way valve 220 connects the discharge side of the compressor 210 to the outdoor heat exchanger 230 and connects the suction side of the compressor 210 to the indoor heat exchanger 110 when cooling operation is performed.
  • a flow path switching device may be formed by combining a plurality of two-way valves.
  • the outdoor heat exchanger 230 is a heat exchanger that exchanges heat between the refrigerant and outdoor air.
  • the outdoor heat exchanger 230 of Embodiment 1 functions as an evaporator during heating operation, absorbs heat from the refrigerant, evaporates it, and vaporizes the refrigerant into a gaseous refrigerant (hereinafter referred to as gas refrigerant).
  • gas refrigerant a gaseous refrigerant
  • it functions as a condenser, condenses the refrigerant, radiates heat, liquefies it as a liquid refrigerant (hereinafter referred to as liquid refrigerant), and passes it through.
  • the configuration of the outdoor heat exchanger 230 will be further explained later.
  • the outdoor blower 250 forms an air flow that causes air from outside the outdoor unit 200 to pass through the outdoor heat exchanger 230 and flow out from the outdoor unit 200, thereby facilitating heat exchange in the outdoor heat exchanger 230. prompt.
  • the expansion valve 240 which serves as a throttle device or the like, is a valve that reduces the pressure of the refrigerant and expands it.
  • the expansion valve 240 is, for example, an electronic expansion valve.
  • the expansion valve 240 adjusts its opening based on instructions from a control device 400 or the like, which will be described later, to reduce the pressure and control the amount of refrigerant passing through.
  • the indoor unit 100 performs indoor air conditioning.
  • the indoor unit 100 includes an indoor heat exchanger 110 as a device that constitutes a refrigerant circuit. Furthermore, the indoor unit 100 includes an indoor blower 120.
  • the indoor heat exchanger 110 is a heat exchanger that exchanges heat between indoor air, which is a space to be air-conditioned, and a refrigerant. For example, during heating operation, indoor heat exchanger 110 functions as a condenser, condenses refrigerant, and passes liquid refrigerant. Further, during cooling operation, the indoor heat exchanger 110 functions as an evaporator, evaporates the refrigerant, and passes the gas refrigerant.
  • the indoor blower 120 causes air to pass through the indoor heat exchanger 110 to promote heat exchange in the indoor heat exchanger 110, and supplies the air that has passed through the indoor heat exchanger 110 to the room that is the space to be air-conditioned.
  • each device in the air conditioner 1 will be explained based on the flow of refrigerant.
  • the operation of each device in the refrigerant circuit during heating operation will be explained based on the flow of refrigerant.
  • Solid line arrows in FIG. 1 indicate the flow of refrigerant during heating operation.
  • the high temperature and high pressure gas refrigerant compressed and discharged by the compressor 210 passes through the four-way valve 220 and flows into the indoor heat exchanger 110. While passing through the indoor heat exchanger 110, the gas refrigerant condenses and liquefies, for example, by exchanging heat with the air in the air-conditioned space.
  • the condensed and liquefied refrigerant passes through expansion valve 240 .
  • the refrigerant passes through the expansion valve 240, the pressure is reduced.
  • the refrigerant whose pressure is reduced by the expansion valve 240 and becomes a gas-liquid two-phase state passes through the outdoor heat exchanger 230.
  • the refrigerant that is evaporated and gasified by exchanging heat with outdoor air sent from the outdoor blower 250 passes through the four-way valve 220 and is sucked into the compressor 210 again.
  • the refrigerant of the air conditioner 1 is circulated, and air conditioning related to heating is performed.
  • Dotted arrows in FIG. 1 indicate the flow of refrigerant during cooling operation.
  • the high temperature and high pressure gas refrigerant compressed and discharged by the compressor 210 passes through the four-way valve 220 and flows into the outdoor heat exchanger 230.
  • the refrigerant passes through the outdoor heat exchanger 230 and exchanges heat with the outdoor air supplied by the outdoor blower 250, thereby condensing and liquefying.
  • the liquefied refrigerant passes through expansion valve 240.
  • the pressure is reduced and the refrigerant enters a gas-liquid two-phase state.
  • the refrigerant whose pressure is reduced by the expansion valve 240 and becomes a gas-liquid two-phase state passes through the indoor heat exchanger 110. Then, in the indoor heat exchanger 110, for example, the refrigerant that is evaporated and gasified by exchanging heat with the air in the air-conditioned space passes through the four-way valve 220 and is sucked into the compressor 210 again. As described above, the refrigerant of the air conditioner 1 circulates, and air conditioning related to cooling is performed.
  • the outdoor heat exchanger 230 performs a heating operation as an evaporator.
  • FIG. 2 is a diagram showing a schematic configuration of an example of the heat exchanger according to the first embodiment.
  • the heat exchanger in FIG. 2 is the outdoor heat exchanger 230, but it is also assumed that the indoor heat exchanger 110 has a similar configuration.
  • the outdoor heat exchanger 230 is, for example, a fin tube type heat exchanger.
  • the outdoor heat exchanger 230 has a heat exchanger main body 231 that exchanges heat between outdoor air and a refrigerant.
  • the heat exchanger main body 231 includes a plurality of heat exchanger tubes that serve as flow paths for the refrigerant and a plurality of fins that promote heat exchange between the refrigerant and outdoor air.
  • the heat exchanger main body 231 has one end connected to a refrigerant distributor 232 via a plurality of capillary tubes 233, and the other end connected to a header 234.
  • the distributor 232 and the header 234 distribute or join the refrigerant to the plurality of heat transfer tubes of the heat exchanger main body 231.
  • a two-phase pipe temperature sensor 500 and a liquid pipe temperature sensor 510 are attached to the outdoor heat exchanger 230.
  • the two-phase pipe temperature sensor 500 and the liquid pipe temperature sensor 510 are detection devices that detect the temperature of the refrigerant at the positions where they are installed and send signals related to the detection to the control device 400, which will be described later.
  • the two-phase pipe temperature sensor 500 detects the temperature of the refrigerant in the heat exchanger as the heat exchanger passing temperature.
  • the two-phase pipe temperature sensor 500 is attached so as to be able to detect the temperature of the refrigerant at a position approximately in the middle of the stroke through the heat exchanger main body 231. do.
  • the two-phase tube temperature sensor 500 is attached to a holder brazed to a U-shaped portion of a hairpin tube included in the heat exchanger body 231.
  • the position where the two-phase tube temperature sensor 500 is attached is, for example, a position where it is assumed that the temperature at point P3 in the ph diagram of FIG. 4, which will be described later, will be detected. Therefore, the heat exchanger passing temperature is usually the saturation temperature (evaporation temperature) of a gas-liquid two-phase refrigerant during the evaporation process of the refrigeration cycle.
  • the liquid pipe temperature sensor 510 is a detection device that detects the temperature of the refrigerant flowing into and out of the outdoor heat exchanger 230 as a liquid pipe temperature, and sends a signal related to the detection to the control device 400.
  • Liquid tube temperature sensor 510 detects the surface temperature of the outlet tube of the heat exchanger that functions as a condenser. The temperature corresponds to the temperature of the liquid refrigerant after condensation.
  • the heat exchanger functions as an evaporator
  • the liquid tube temperature sensor 510 detects the surface temperature of the inlet tube of the heat exchanger. The temperature corresponds to the temperature of a two-phase refrigerant with high wetness before evaporation.
  • the outdoor heat exchanger 230 when the outdoor heat exchanger 230 functions as an evaporator, it is a two-phase refrigerant temperature sensor that detects the temperature of a two-phase refrigerant with high humidity including liquid refrigerant flowing into the outdoor heat exchanger 230.
  • the liquid pipe temperature sensor 510 is attached via the refrigerant pipe 300 at a position that serves as a refrigerant flow path between the expansion valve 240 and the outdoor heat exchanger 230.
  • the liquid tube temperature sensor 510 is attached to a capillary tube 233 that connects the heat exchanger main body 231 and the distributor 232.
  • the outdoor heat exchanger 230 functions as a condenser
  • the liquid pipe temperature sensor 510 detects the temperature of the refrigerant flowing out from the outdoor heat exchanger 230.
  • FIG. 3 is a diagram illustrating the configuration of the control device 400 in the air conditioner 1 according to the first embodiment.
  • the control device 400 is a device that controls the air conditioner 1. Although the description here assumes that the outdoor unit 200 includes the control device 400, the present invention is not limited to this. Other units may include the control device 400. Further, the control device 400 may be a device independent from a unit having devices constituting the air conditioner 1.
  • the control device 400 includes a control section 410, a storage section 420, and a display section 430.
  • the control unit 410 includes, for example, a control processing unit such as a CPU (Central Processing Unit) or a microcomputer.
  • the control unit 410 in the first embodiment particularly includes a determination unit 411, a correction unit 412, a dry protection control unit 413, and a circulation amount estimation unit 414.
  • the determination unit 411 performs determination processing regarding dry protection control. For this reason, for example, the determination unit 411 includes a correction determination unit 411A that determines a correction value (degree of correction) to be corrected by the correction unit 412 with respect to the heat exchanger passing temperature detected by the two-phase pipe temperature sensor 500. .
  • the determination unit 411 includes a dry protection determination unit 411B that determines whether the dry protection control unit 413 performs dry protection control.
  • the correction unit 412 corrects the heat exchanger passage temperature using a correction value based on the determination by the correction determination unit 411A.
  • the dry protection control unit 413 performs dry protection control when the dry protection determining unit 411B determines that dry protection is to be performed.
  • the content of the dry protection control performed by the dry protection control section 413 is not particularly limited.
  • the dry protection control unit 413 performs control to lower the drive frequency of the compressor 210.
  • the dry protection control unit 413 performs control to lower the drive frequency of the compressor 210, thereby lowering the discharge temperature of the refrigerant discharged by the compressor 210, thereby protecting the compressor 210. Further, the dryness protection control unit 413 may stop the operation of the air conditioner 1 as dryness protection control.
  • the circulation amount estimation unit 414 then estimates the circulation amount of refrigerant passing through the heat exchanger serving as the evaporator. In the first embodiment, the circulation amount estimation unit 414 includes a drive frequency acquisition unit 414A, and estimates the circulation amount based on the obtained drive frequency of the compressor 210.
  • the storage unit 420 also includes, for example, a volatile storage device (not shown) such as a random access memory (RAM) that can temporarily store data, and a non-volatile auxiliary storage device (not shown) such as a flash memory.
  • a volatile storage device such as a random access memory (RAM) that can temporarily store data
  • a non-volatile auxiliary storage device such as a flash memory.
  • the storage unit 420 stores the relationship among the amount of refrigerant circulation, the evaporation temperature in the evaporator, and the correction value as data in a table format. It also stores data of a set threshold value used when the determination unit 411 makes a determination.
  • the set threshold value, correction value, etc. are set in advance through experiments or the like based on the refrigerant circulation amount and evaporation temperature.
  • the storage unit 420 has data in which a processing procedure performed by the control arithmetic processing device is a program.
  • the control unit 410 then executes processing based on the data of the program.
  • the control device 400 may be a device (hardware) dedicated to control.
  • the display unit 430 includes, for example, a display device such as a monitor that displays the status of the air conditioner 1 and the like.
  • the display section 430 performs a display related to dry protection.
  • FIG. 4 is a pH diagram of the refrigeration cycle device.
  • the temperature of the refrigerant which serves as a reference for determining the dry state of the refrigerant, is the heat exchanger passage temperature detected by the two-phase pipe temperature sensor 500 described above.
  • the two-phase tube temperature sensor 500 is arranged to detect the temperature of the refrigerant at a point P3 on the ph diagram (Mollier diagram) shown in FIG.
  • the pressure of the refrigerant in the evaporator is determined from point P3a, which is the refrigerant inlet of the evaporator, to point P3b, which is the refrigerant outlet, through point P3, and the pressure on the evaporator side (low pressure side of the refrigerant circuit).
  • a general characteristic of refrigerants is a tendency to decrease by the amount of loss.
  • FIG. 5 is a diagram showing the relationship between pressure and temperature in the evaporation process of a non-azeotropic mixed refrigerant when the pressure in the evaporator is constant in the refrigeration cycle device according to the first embodiment.
  • FIG. 6 is a diagram showing the relationship between pressure and temperature in the evaporation process of the non-azeotropic mixed refrigerant when a pressure difference occurs in the evaporator in the refrigeration cycle device according to the first embodiment.
  • the arrows shown in FIGS. 5 and 6 indicate the direction in which the refrigerant flows.
  • the boiling points of the refrigerants involved in the mixture are different. Therefore, the enthalpy increases and the temperature of the refrigerant also increases. Therefore, as shown in FIG. 5, for example, if there is no pressure difference or can be ignored between the pressure at point P3a and the pressure at point P3b, due to the physical properties of the non-azeotropic mixed refrigerant, the refrigerant inlet of the evaporator The temperature of the refrigerant increases from the point to the refrigerant outlet.
  • the liquid pipe temperature of the non-azeotropic mixed refrigerant tends to be lower than the heat exchanger passing temperature, as detected by the two-phase pipe temperature sensor 500.
  • a non-azeotropic mixed refrigerant even if the refrigerant is in a gas-liquid two-phase state in the evaporation process, it will exhibit the same temperature trend as a refrigerant in a superheated state.
  • refrigerant in a gas-liquid two-phase state flows within the evaporator at point P3, but if refrigerant leaks from the refrigerant circuit, there is a shortage of refrigerant in the refrigerant circuit. If so, the refrigerant may already be in an overheated state at point P3. In the case of a refrigerant that has a temperature gradient, it may be difficult to distinguish this from a refrigerant shortage condition.
  • the correction unit 412 corrects the heat exchanger passing temperature based on the determination by the determination unit 411.
  • FIG. 7 is a diagram showing a change in refrigerant temperature over time when the amount of refrigerant circulation is small in the outdoor heat exchanger 230 of the air conditioner 1 according to the first embodiment.
  • FIG. 8 is a diagram showing a temporal change in the refrigerant temperature when the amount of refrigerant circulation is large in the outdoor heat exchanger 230 of the air conditioner 1 according to the first embodiment.
  • the outdoor heat exchanger 230 here functions as an evaporator.
  • the pressure difference that occurs within the evaporator changes depending on the amount of refrigerant circulated. When the amount of refrigerant circulation is large, the pressure loss is large, and when the amount of refrigerant circulation is small, the pressure loss is small.
  • the determination unit 411 of the control device 400 determines whether the heat exchanger related to the temperature gradient is determined based on the heat exchanger passing temperature detected by the two-phase pipe temperature sensor 500. A correction value for the temperature passing through the chamber is determined and corrected by the correction unit 412. Then, the determination unit 411 of the control device 400 determines whether or not to perform dry protection based on the corrected heat exchanger passage temperature, and the dry protection control unit 413 performs dry protection control based on the determination. Therefore, the actual heat exchanger passing temperature detected by the two-phase pipe temperature sensor 500 can be corrected to a more accurate temperature. Therefore, the control device 400 of the air conditioner 1 can more accurately determine the dry state and perform dry protection control based on the determination. In addition, in the air conditioner 1 of the first embodiment, the control device 400 can more accurately determine the dryness protection based on the temperature of the refrigerant detected by the two-phase pipe temperature sensor 500 with a small number of temperature sensors. It can be carried out.
  • FIG. 9 is a diagram illustrating dry protection control processing of the refrigeration cycle device according to the second embodiment.
  • the processing in FIG. 9 will be described as being performed by the control device 400.
  • the circulation amount estimating section 414 of the control device 400 includes the driving frequency acquiring section 414A, as described above. Therefore, the circulation amount estimation unit 414 estimates the refrigerant circulation amount based on the drive frequency of the compressor 210 (step S1).
  • the refrigerant circulation amount can generally be obtained based on the following equation (1).
  • Refrigerant circulation amount volumetric efficiency x driving frequency x suction refrigerant density x displacement volume...(1)
  • the drive frequency is a term that affects when estimating the amount of refrigerant circulation. Therefore, in the second embodiment, when the circulation amount estimation unit 414 estimates the refrigerant circulation amount, it is assumed that the volumetric efficiency, the suction refrigerant density, and the displacement volume are constant values. Therefore, the amount of refrigerant circulation can be approximated as an amount that depends on the driving frequency of the compressor 210.
  • the correction determination unit 411A of the determination unit 411 compares the estimated refrigerant circulation amount with a set threshold value stored in the storage unit 420, and determines whether the refrigerant circulation amount is equal to or greater than the set threshold value. is determined (step S2).
  • the set threshold value is set, for example, to a value that provides a refrigerant circulation amount that is 50% of the maximum refrigerant circulation amount of the refrigerant passing through the indoor unit 100.
  • a set threshold value is set for the maximum refrigerant circulation amount in each indoor unit 100, respectively.
  • the correcting unit 412 corrects the heat exchanger passage temperature detected by the two-phase pipe temperature sensor 500 with the first correction value (Ste S3).
  • the correction determination unit 411A determines that the refrigerant circulation amount is smaller than the set threshold value, the heat exchanger detected by the two-phase pipe temperature sensor 500 will be The passing temperature is corrected (step S4).
  • the second correction value may be zero.
  • the correction unit 412 corrects the first correction value and the second correction value corresponding to the evaporation temperature.
  • the first correction value and the second correction value are stored in the storage unit 420 as data.
  • the dry protection determining unit 411B of the determining unit 411 determines whether to perform dry protection based on the corrected heat exchanger passage temperature (step S5). If the dry protection determining unit 411B determines that dry protection is not to be performed, the process returns to step S1.
  • the dry protection control unit 413 starts dry protection and performs processing related to dry protection control (step S6).
  • the content of the dry protection control performed by the dry protection control section 413 is not particularly limited.
  • the dry protection control unit 413 may first protect the compressor 210 by lowering the driving frequency of the compressor 210 and controlling the discharge temperature of the refrigerant discharged by the compressor 210. Further, the dry protection control unit 413 may stop the operation of the air conditioner 1. At this time, the display unit 430 of the control device 400 may display that dry protection control is being performed. When the dry protection control unit 413 of the control device 400 finishes the dry protection control, the process returns to step S1.
  • the effects described in the first embodiment can be obtained. Furthermore, in the air conditioner 1 according to the second embodiment, the control device 400 corrects the heat exchanger passage temperature based on the drive frequency. Therefore, a more accurate refrigerant circulation amount can be easily obtained.
  • FIG. 10 is a diagram showing the configuration of a control device 400 according to the third embodiment.
  • the circulation amount estimating section 414 of the control device 400 in the third embodiment includes an intake temperature determining section 414B.
  • the suction temperature determination unit 414B determines the suction temperature of the refrigerant sucked into the compressor 210 based on the heat exchanger passing temperature detected by the two-phase tube temperature sensor 500 attached to the evaporator.
  • the circulation amount estimation unit 414 of the second embodiment estimates the refrigerant circulation amount based on the drive frequency of the compressor 210 and the suction density based on the suction temperature determined by the suction temperature determination unit 414B.
  • the control device 400 determines and corrects the correction value based on the refrigerant circulation amount of the refrigerant circulating in the refrigerant circuit. Therefore, if the control device 400 can obtain a more accurate refrigerant circulation amount, it can perform more accurate correction.
  • the circulation amount estimation unit 414 of the control device 400 estimates the refrigerant circulation amount by setting the suction refrigerant density to a constant value.
  • Control device 400 in Embodiment 3 estimates the refrigerant circulation amount based not only on the drive frequency of compressor 210 but also on the suction refrigerant density obtained from the suction temperature of the refrigerant suctioned by compressor 210.
  • the control section 410 of the control device 400 includes the suction temperature determination section 414B, and determines the suction temperature based on the heat exchanger passage temperature. Therefore, the control device 400 can estimate the refrigerant circulation amount including the suction refrigerant density obtained from the suction temperature. Therefore, since the control device 400 can more accurately estimate the refrigerant circulation amount and make a determination, it can more accurately determine whether or not to perform dry protection control.
  • the refrigeration cycle device according to the third embodiment is the air conditioner 1 that performs air conditioning in a target space, it is possible to provide comfortable air conditioning for people in the room.
  • FIG. 11 is a diagram showing the configuration of a control device 400 according to the fourth embodiment.
  • Control device 400 in Embodiment 4 has suction temperature estimation section 414C.
  • the suction temperature estimation unit 414C estimates the suction temperature of the refrigerant sucked into the compressor 210 based on the opening degree of the expansion valve 240.
  • the circulation amount estimating section 414 of the fourth embodiment estimates the refrigerant circulation amount based on the drive frequency of the compressor 210 and the suction temperature estimated by the suction temperature estimating section 414C.
  • the suction temperature estimation unit 414C can obtain the Cv value of the expansion valve 240 based on the opening degree of the expansion valve 240.
  • the Cv value is a value determined by the type and port diameter of the expansion valve 240, and is the capacity coefficient of the valve.
  • the Cv value is a numerical representation of the flow rate of fluid passing through a valve at a given pressure difference.
  • the suction temperature estimating unit 414C estimates the low pressure on the low pressure side of the refrigerant circuit from the Cv value and the amount of refrigerant circulation, and further estimates the suction temperature.
  • the control device 400 can estimate not only the driving frequency of the compressor 210 but also the refrigerant circulation amount based on the estimated suction temperature.
  • the suction temperature estimating unit 414C of the control device 400 operates based on the opening degree of the expansion valve 240 that expands high-pressure refrigerant and depressurizes it to low-pressure refrigerant. , estimate the inlet temperature. Therefore, it is possible to obtain a more accurate amount of refrigerant circulation and make a determination, and control can be performed efficiently.
  • the refrigeration cycle device according to the fourth embodiment is the air conditioner 1 that performs air conditioning in a target space, comfortable air conditioning can be performed for people in the room.
  • control section 410 of the control device 400 has the suction temperature determination section 414B
  • control section 410 of the control device 400 has the suction temperature estimation section 414C. there were. However, it is not limited to those having either one of them.
  • the control unit 410 of the control device 400 may be configured to include both an intake temperature determination unit 414B and an intake temperature estimation unit 414C, and may perform respective processes.
  • the refrigeration cycle device of the first embodiment described above uses R454B refrigerant in which R32 refrigerant and R1234yf refrigerant are mixed at a ratio of 68.1:31.9 as the non-azeotropic mixed refrigerant that circulates in the refrigerant circuit.
  • R454B refrigerant in which R32 refrigerant and R1234yf refrigerant are mixed at a ratio of 68.1:31.9 as the non-azeotropic mixed refrigerant that circulates in the refrigerant circuit.
  • a non-azeotropic refrigerant mixture such as R407C may be used.
  • a pseudo-azeotropic refrigerant mixture having a temperature gradient may be used.
  • the refrigeration cycle device can be applied to various types of non-azeotropic mixed refrigerants, a refrigerant with a low GWP can be employed, and the refrigeration cycle device can be made in consideration of the global environment. Further, the refrigeration cycle device can be made compliant with the standards and standards of each region of the market.
  • the configuration of the refrigerant circuit in the refrigeration cycle device is not limited to the configuration of the air conditioner 1 in FIG. 1 described in the first embodiment described above.
  • the refrigeration cycle device may have an accumulator between the evaporator, which is the low-pressure side of the refrigerant circuit, and the suction side of the compressor 210.
  • the accumulator is a container that allows gas refrigerant to pass through and stores liquid refrigerant.
  • the refrigeration cycle device may have a receiver between the expansion valve 240 and a heat exchanger serving as a condenser on the high-pressure side of the refrigerant circuit.
  • the receiver is a container that stores excess refrigerant in the refrigerant circuit on the high-pressure side of the refrigerant circuit.
  • the heat exchanger passing temperature is corrected in the control device 400 using the first correction value or the second correction value based on the set threshold value, but the present invention is not limited to this.
  • the storage unit 420 may store a plurality of set threshold values as data so that the amount of refrigerant circulation is divided into three or more categories, and the correction value may be corrected using a correction value corresponding to each category. Further, if the relationship between the environmental state of the refrigerant during the evaporation process and the correction value can be expressed by a mathematical formula, the correction value may be calculated by calculation or the like.
  • the heat exchanger is used as the outdoor heat exchanger 230 of the outdoor unit 200, but the present invention is not limited to this. It may be used for the indoor heat exchanger 110 of the indoor unit 100, or may be used for both the outdoor heat exchanger 230 and the indoor heat exchanger 110.
  • the air conditioner 1 has been described, but the present invention can also be applied to other refrigeration cycle devices, such as a refrigerator, a freezing device, and a hot water supply device.
  • other refrigeration cycle devices such as a refrigerator, a freezing device, and a hot water supply device.
  • Air conditioner 100 Indoor unit, 110 Indoor heat exchanger, 120 Indoor blower, 200 Outdoor unit, 210 Compressor, 220 Four-way valve, 230 Outdoor heat exchanger, 231 Heat exchanger body, 232 Distributor, 233 Capillary tube , 234 header, 240 expansion valve, 250 outdoor blower, 300 refrigerant piping, 400 control device, 410 control unit, 411 determination unit, 411A correction determination unit, 411B dry protection determination unit, 412 correction unit, 413 dry protection control unit, 414 Circulation amount estimation section, 414A driving frequency acquisition section, 414B suction temperature determination section, 414C suction temperature estimation section, 420 storage section, 430 display section, 500 two-phase tube temperature sensor, 510 liquid tube temperature sensor.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Thermal Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Air Conditioning Control Device (AREA)
PCT/JP2022/032912 2022-09-01 2022-09-01 冷凍サイクル装置および空気調和装置 Ceased WO2024047832A1 (ja)

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH08320158A (ja) * 1995-05-26 1996-12-03 Matsushita Refrig Co Ltd 冷暖房装置
JP2011179746A (ja) * 2010-03-01 2011-09-15 Mitsubishi Electric Corp 空気調和機及び空気調和機の高圧圧力抑制制御方法
JP2012220042A (ja) * 2011-04-04 2012-11-12 Mitsubishi Electric Corp 空気調和装置
JP2017053566A (ja) * 2015-09-10 2017-03-16 ジョンソンコントロールズ ヒタチ エア コンディショニング テクノロジー（ホンコン）リミテッド 冷凍サイクル装置
JP2021014962A (ja) * 2019-07-12 2021-02-12 ダイキン工業株式会社 冷凍装置の室内機

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007101126A (ja) 2005-10-06 2007-04-19 Mitsubishi Electric Corp 空気調和装置

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH08320158A (ja) * 1995-05-26 1996-12-03 Matsushita Refrig Co Ltd 冷暖房装置
JP2011179746A (ja) * 2010-03-01 2011-09-15 Mitsubishi Electric Corp 空気調和機及び空気調和機の高圧圧力抑制制御方法
JP2012220042A (ja) * 2011-04-04 2012-11-12 Mitsubishi Electric Corp 空気調和装置
JP2017053566A (ja) * 2015-09-10 2017-03-16 ジョンソンコントロールズ ヒタチ エア コンディショニング テクノロジー（ホンコン）リミテッド 冷凍サイクル装置
JP2021014962A (ja) * 2019-07-12 2021-02-12 ダイキン工業株式会社 冷凍装置の室内機

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