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JP-2026074663-A - Refrigeration cycle system

JP2026074663AJP 2026074663 AJP2026074663 AJP 2026074663AJP-2026074663-A

Abstract

[Problem] To provide a refrigeration cycle system that can appropriately detect abnormalities in the refrigerant circuit. [Solution] The refrigeration cycle system according to this disclosure includes measuring means for measuring relevant physical quantities related to the state of the refrigerant circuit. When the abnormality determination mode is started, the control means sets the depressurization device to a first depressurization state, measures the value of the relevant physical quantity as a first measurement value by the measuring means when a first time has elapsed, then switches from the first depressurization state to a second depressurization state and measures the value of the relevant physical quantity as a second measurement value by the measuring means. If the value obtained by subtracting the first measurement value from the second measurement value is less than or equal to the first abnormality determination value, and the value obtained by subtracting the second measurement value from the first measurement value is less than or equal to the second abnormality determination value which is smaller than the first abnormality determination value, it is counted as an abnormality count, and when the cumulative count of abnormality counts exceeds a predetermined number of determination counts, it is determined that there is an abnormality in the refrigerant circuit. [Selection Diagram] Figure 2

Inventors

  • 藤丸 雄也
  • 広崎 大樹

Assignees

  • 三菱電機株式会社

Dates

Publication Date
20260507
Application Date
20241021

Claims (9)

  1. A compressor that compresses the refrigerant, A cooler for cooling the refrigerant compressed by the compressor, A pressure reducing device for reducing the pressure of the refrigerant that has passed through the cooler, A refrigerant circuit having an evaporator that evaporates the refrigerant that has passed through the pressure reducing device, A measuring means for measuring a related physical quantity which is a physical quantity related to the state of the refrigerant circuit, A control means that executes an abnormality determination mode to detect an abnormality in the refrigerant circuit when starting the operation of the refrigeration cycle using the refrigerant circuit, Equipped with, The pressure reducing device is switchable between a first pressure reduction state and a second pressure reduction state in which the pressure reduction is smaller than that of the first pressure reduction state. When the abnormality detection mode is started, the control means sets the pressure reducing device to the first pressure reduction state and operates the compressor at the first speed. The control means is After the first hour has elapsed since the start of the abnormality determination mode, the measurement means measures the value of the relevant physical quantity as the first measured value, and then the depressurization device is switched from the first depressurization state to the second depressurization state. After the pressure reducing device is switched from the first pressure reduction state to the second pressure reduction state, the value of the related physical quantity is measured by the measuring means as the second measured value. If the value obtained by subtracting the first measurement value from the second measurement value is greater than the first abnormality determination value, it is determined that there is an abnormality in the refrigerant circuit, and the operation of the compressor is stopped. If the value obtained by subtracting the first measurement value from the second measurement value is less than or equal to the first abnormality judgment value, and the value obtained by subtracting the second measurement value from the first measurement value is less than or equal to the second abnormality judgment value which is smaller than the first abnormality judgment value, then it is counted as an abnormality, the pressure reducing device is returned to the first pressure reduction state, and then the operation of the compressor is continued by returning to the start of the abnormality judgment mode. A refrigeration cycle system configured to determine that there is an abnormality in the refrigerant circuit and to stop the operation of the compressor when the cumulative count of the number of abnormalities exceeds a predetermined number of determinations.
  2. The refrigeration cycle system according to claim 1, wherein the measuring means measures the current driving the compressor as the relevant physical quantity.
  3. The refrigeration cycle system according to claim 1, wherein the measuring means measures the temperature of the compressor as the relevant physical quantity.
  4. The refrigeration cycle system according to claim 1, wherein the measuring means measures the temperature of the refrigerant discharged from the compressor as the relevant physical quantity.
  5. A compressor that compresses the refrigerant, A cooler for cooling the refrigerant compressed by the compressor, A pressure reducing device for reducing the pressure of the refrigerant that has passed through the cooler, An evaporator for evaporating the refrigerant that has passed through the pressure reducing device, A refrigerant circuit having a fluid actuator that flows air through the evaporator, A measuring means for measuring a related physical quantity which is a physical quantity related to the state of the refrigerant circuit, A control means that executes an abnormality determination mode to detect an abnormality in the refrigerant circuit when starting the operation of the refrigeration cycle using the refrigerant circuit, Equipped with, The pressure reducing device is switchable between a first pressure reduction state and a second pressure reduction state in which the pressure reduction is smaller than that of the first pressure reduction state. When the abnormality detection mode is started, the control means sets the pressure reducing device to the first pressure reduction state and operates the fluid actuator at the second speed. After the first hour has elapsed since the start of the abnormality detection mode, the compressor temperature is measured, and then the compressor is operated at the first speed. The control means is After the second time has elapsed since the start of the abnormality determination mode, the measurement means measures the value of the relevant physical quantity as the first measured value, and then the depressurization device is switched from the first depressurization state to the second depressurization state. After the pressure reducing device is switched from the first pressure reduction state to the second pressure reduction state, the value of the related physical quantity is measured by the measuring means as the second measured value. If the value obtained by subtracting the first measurement value from the second measurement value is greater than the first abnormality determination value, it is determined that there is an abnormality in the refrigerant circuit, and the operation of the compressor is stopped. If the value obtained by subtracting the first measurement value from the second measurement value is less than or equal to the first abnormality judgment value, and the value obtained by subtracting the second measurement value from the first measurement value is less than or equal to the second abnormality judgment value which is smaller than the first abnormality judgment value, then the operation of the compressor shall be stopped. A refrigeration cycle system configured such that the second abnormality determination value is determined from the compressor temperature measured at the time the first time has elapsed since the start of the abnormality determination mode.
  6. The refrigeration cycle system according to claim 5, wherein the second abnormality determination value is determined from the temperature of the refrigerant discharged from the compressor.
  7. The refrigeration cycle system according to claim 5, wherein the measuring means measures the current driving the compressor as the relevant physical quantity.
  8. The refrigeration cycle system according to claim 5, wherein the measuring means measures the temperature of the compressor as the relevant physical quantity.
  9. The refrigeration cycle system according to claim 5, wherein the measuring means measures the temperature of the refrigerant discharged from the compressor as the relevant physical quantity.

Description

This disclosure relates to a refrigeration cycle system. Patent Document 1, described below, discloses a technique for determining abnormalities in the refrigerant circuit of a heat pump water heater. This technique involves setting the pressure reducing device to a first pressure reduction state, operating the compressor at a first speed, and if the value obtained by subtracting the current value measured after the pressure reduction is switched to a second pressure reduction state from the current value measured after the first time has elapsed is greater than the first abnormality determination value, the compressor operation is stopped. International Publication No. 2022/044321 This figure shows a refrigeration cycle system according to Embodiment 1.This flowchart shows an example of the processing performed by the control unit in the abnormality detection mode of Embodiment 1.This figure shows an example of a graph illustrating the time-dependent changes in related physical quantities after a compressor has been started.This figure shows examples of graphs illustrating the time-dependent changes in related physical quantities under conditions where the compressor drive load is likely to be high and under conditions where the compressor drive load is unlikely to be high.This flowchart shows an example of the processing performed by the control unit in the abnormality detection mode of Embodiment 4.This figure shows a refrigeration cycle system according to Embodiment 4. The embodiments will be described below with reference to the drawings. Common or corresponding elements in each drawing are denoted by the same reference numerals, and their descriptions are simplified or omitted. Embodiment 1. Figure 1 shows a refrigeration cycle system according to Embodiment 1. As shown in Figure 1, the refrigeration cycle system 1 comprises a refrigerant circuit 2, a measuring unit 7, and a control unit 8. The refrigerant circuit 2 comprises a compressor 3 for compressing the refrigerant, a cooler 4 for cooling the high-pressure refrigerant compressed by the compressor 3, a pressure reducing device 5 for reducing the pressure of the high-pressure refrigerant that has passed through the cooler 4, and an evaporator 6 for evaporating the low-pressure refrigerant reduced in pressure by the pressure reducing device 5. The compressor 3, cooler 4, pressure reducing device 5, and evaporator 6 are connected via refrigerant piping to form a ring-shaped circuit. The low-pressure refrigerant gas flowing out of the evaporator 6 is drawn into the compressor 3 and circulates again through the refrigerant circuit 2. The refrigerant circuit 2 is operated by electricity. The refrigerant sealed in the refrigerant circuit 2 is not particularly limited, but may include, for example, carbon dioxide, ammonia, propane, isobutane, fluorocarbons such as HFCs, HFO-1123, or HFO-1234yf. The cooler 4 corresponds to a heat exchanger that exchanges heat between the high-pressure refrigerant discharged from the compressor 3 and a first fluid that is at a lower temperature than the high-pressure refrigerant. In the cooler 4, the temperature of the first fluid rises as it is heated by the high-pressure refrigerant. The first fluid may be a liquid, such as water or another liquid heat transfer medium, or a gas, such as outdoor or indoor air. The refrigeration cycle system 1 may be equipped with a first fluid actuator (not shown), such as a pump or blower, for flowing the first fluid to the cooler 4. The pressure reducing device 5 expands the high-pressure refrigerant to convert it to low-pressure refrigerant. The pressure reducing device 5 may also be an expansion valve with adjustable refrigerant passage opening. The low-pressure refrigerant that passes through the pressure reducing device 5 becomes a two-phase gas-liquid state. The evaporator 6 corresponds to a heat exchanger that exchanges heat between the low-pressure refrigerant, which has been reduced in pressure by the depressurization device 5, and a second fluid that is at a higher temperature than this low-pressure refrigerant. The refrigerant in the evaporator 6 evaporates by absorbing heat from the second fluid. The second fluid may be a gas, such as outdoor or indoor air, or a liquid, such as water or another liquid heat transfer medium. The refrigeration cycle system 1 may also include a second fluid actuator (not shown), such as a blower or pump, for flowing the second fluid to the evaporator 6. The refrigeration cycle system 1 may be used to heat the first fluid using the cooler 4, or to cool the second fluid using the evaporator 6. For example, the refrigeration cycle system 1 may be used in at least one of the following: a heat pump hot water supply system, a heat pump heating system, or an air conditioning system. The physical quantities related to the state of the refrigerant circuit 2 are hereinafter referred to as "related physical quantities." The measurement unit 7 corresponds