EP3885676A1 - Refrigerant cycle device, refrigerant amount determination system, and refrigerant amount determination method - Google Patents
Refrigerant cycle device, refrigerant amount determination system, and refrigerant amount determination method Download PDFInfo
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- EP3885676A1 EP3885676A1 EP19887164.2A EP19887164A EP3885676A1 EP 3885676 A1 EP3885676 A1 EP 3885676A1 EP 19887164 A EP19887164 A EP 19887164A EP 3885676 A1 EP3885676 A1 EP 3885676A1
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- European Patent Office
- Prior art keywords
- refrigerant
- temperature
- temperature difference
- amount
- air
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B49/00—Arrangement or mounting of control or safety devices
- F25B49/005—Arrangement or mounting of control or safety devices of safety devices
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B49/00—Arrangement or mounting of control or safety devices
- F25B49/02—Arrangement or mounting of control or safety devices for compression type machines, plants or systems
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B13/00—Compression machines, plants or systems, with reversible cycle
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2500/00—Problems to be solved
- F25B2500/19—Calculation of parameters
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2500/00—Problems to be solved
- F25B2500/22—Preventing, detecting or repairing leaks of refrigeration fluids
- F25B2500/222—Detecting refrigerant leaks
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2700/00—Sensing or detecting of parameters; Sensors therefor
- F25B2700/21—Temperatures
- F25B2700/2106—Temperatures of fresh outdoor air
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2700/00—Sensing or detecting of parameters; Sensors therefor
- F25B2700/21—Temperatures
- F25B2700/2116—Temperatures of a condenser
Definitions
- the present disclosure relates to a refrigeration cycle apparatus, a refrigerant amount determination system, and a refrigerant amount determination method.
- PTL 1 Japanese Unexamined Patent Application Publication No. H6-159869 determines the amount of the refrigerant on the basis of a difference between a refrigerant temperature and an inlet air temperature and a preset compressor protection-limit temperature difference and stops operation of the compressor.
- the technique in PTL 1 is incapable of grasping a decrease in the amount of the refrigerant from an initial amount of the refrigerant, and the determination of the amount of the refrigerant is insufficient for the purpose other than protection of the compressor.
- a refrigerant circulates in a refrigerant circuit constituted by a compressor, a condenser, an expansion mechanism, and an evaporator being connected.
- the refrigeration cycle apparatus includes an air temperature sensor, a condensation temperature sensor, an acquisition unit, and a determination unit.
- the air temperature sensor detects an air temperature, which is a temperature of air that flows into the condenser.
- the condensation temperature sensor detects a condensation temperature of the refrigerant that flows through the condenser.
- the acquisition unit acquires a temperature difference between the air temperature and the condensation temperature.
- the determination unit determines an amount of the refrigerant included in the refrigerant circuit by comparing a first temperature difference and a second temperature difference with each other.
- the first temperature difference is a temperature difference acquired by the acquisition unit at a first timing.
- the second temperature difference is a temperature difference acquired by the acquisition unit at a second timing.
- the refrigeration cycle apparatus herein compares the first temperature difference and the second temperature difference with each other and determines the amount of the refrigerant included in the refrigerant circuit. Thus, it can be determined whether the refrigerant leaks from the refrigerant circuit to the outside by accidental means.
- a refrigeration cycle apparatus is the refrigeration cycle apparatus according to the first aspect further including a storage unit.
- the storage unit stores at least one of the first temperature difference or the air temperature and the condensation temperature acquired at the first timing.
- a refrigeration cycle apparatus is the refrigeration cycle apparatus according to the first or second aspect, in which the first timing is any of a time at which the refrigeration cycle apparatus is installed, at a time of initial operation of the refrigeration cycle apparatus, or a time of maintenance of the refrigeration cycle apparatus.
- a refrigeration cycle apparatus is the refrigeration cycle apparatus according to any of the first to third aspects, in which, if a difference between the first temperature difference and the second temperature difference is greater than or equal to a threshold that is any value from 2°C to 4°C, the determination unit determines that the amount of the refrigerant included in the refrigerant circuit is insufficient.
- a refrigeration cycle apparatus is the refrigeration cycle apparatus according to any of the first to fourth aspects, further including a notification unit that notifies insufficiency of the amount of the refrigerant if the determination unit determines that the amount of the refrigerant is insufficient.
- a refrigeration cycle apparatus is the refrigeration cycle apparatus according to any of the first to fifth aspects, further including a correction unit that corrects the first temperature difference and the second temperature difference by using at least either one of the air temperature or an evaporation temperature of the refrigerant.
- a refrigerant amount determination system is a refrigerant amount determination system that determines an amount of a refrigerant included in a refrigeration cycle apparatus.
- the refrigerant circulates in a refrigerant circuit constituted by a compressor, a condenser, an expansion mechanism, and an evaporator being connected.
- the refrigerant amount determination system includes an air temperature sensor, a condensation temperature sensor, an acquisition unit, and a determination unit.
- the air temperature sensor detects an air temperature, which is a temperature of air that flows into the condenser.
- the condensation temperature sensor detects a condensation temperature of the refrigerant that flows through the condenser.
- the acquisition unit acquires a temperature difference between the air temperature and the condensation temperature.
- the determination unit determines the amount of the refrigerant included in the refrigerant circuit by comparing a first temperature difference and a second temperature difference with each other.
- the first temperature difference is a temperature difference acquired by the acquisition unit at a first timing.
- the second temperature difference is a temperature difference acquired by the acquisition unit at a second timing.
- the refrigeration cycle apparatus herein compares the first temperature difference and the second temperature difference with each other and determines the amount of the refrigerant included in the refrigerant circuit. Thus, it can be determined whether the refrigerant leaks from the refrigerant circuit to the outside by accidental means.
- a refrigerant amount determination system is the refrigerant amount determination system according to the seventh aspect further including a storage unit.
- the storage unit stores at least one of the first temperature difference or the air temperature and the condensation temperature acquired at the first timing.
- a refrigerant amount determination system is the refrigerant amount determination system according to the seventh or eighth aspect, in which the first timing is any of a time at which the refrigeration cycle apparatus is installed, at a time of initial operation of the refrigeration cycle apparatus, or a time of maintenance of the refrigeration cycle apparatus.
- a refrigerant amount determination system is the refrigerant amount determination system according to any of the seventh to ninth aspects, in which, if a difference between the first temperature difference and the second temperature difference is greater than or equal to a threshold that is any value from 2°C to 4°C, the determination unit determines that the amount of the refrigerant included in the refrigerant circuit is insufficient.
- a refrigerant amount determination system is the refrigerant amount determination system according to any of the seventh to tenth aspects further including a notification unit that notifies insufficiency of the amount of the refrigerant if the determination unit determines that the amount of the refrigerant is insufficient.
- a refrigerant amount determination system is the refrigerant amount determination system according to any of the seventh to eleventh aspects further including a correction unit that corrects the first temperature difference and the second temperature difference by using the air temperature or an evaporation temperature of the refrigerant.
- a refrigerant amount determination method is a refrigerant amount determination method for determining an amount of a refrigerant included in a refrigeration cycle apparatus.
- the refrigerant circulates in a refrigerant circuit constituted by a compressor, a condenser, an expansion mechanism, and an evaporator being connected.
- the refrigerant amount determination method includes a first step, a second step, and a third step. In the first step, a first temperature difference is acquired.
- the first temperature difference is a temperature difference detected at a first timing, between an air temperature and a condensation temperature, the air temperature being a temperature of air that flows into the condenser, the condensation temperature being a condensation temperature of the refrigerant that flows through the condenser.
- a second temperature difference is acquired.
- the second temperature difference is a temperature difference detected at a second timing, between the air temperature and the condensation temperature, the air temperature being a temperature of air that flows into the condenser, the condensation temperature being a condensation temperature of the refrigerant that flows through the condenser.
- a change in the amount of the refrigerant included in the refrigerant circuit is determined by comparing the first temperature difference and the second temperature difference with each other.
- Fig. 1 schematically illustrates the air conditioner 100 according to this embodiment.
- the air conditioner 100 performs indoor cooling and heating for buildings or the like by performing a vapor compression refrigeration cycle.
- the air conditioner 100 mainly includes an indoor unit 10, an outdoor unit 20, a refrigerant connection pipe 15 that connects the indoor unit 10 and the outdoor unit 20, and a refrigerant amount determination unit 30 that determines the amount of a refrigerant that flows through a refrigerant circuit 16.
- the refrigerant circuit 16 of the air conditioner 100 is constituted by the indoor unit 10 and the outdoor unit 20 being connected via the refrigerant connection pipe 15.
- R410A, R32, R407C, R22, R134a, carbon dioxide, or the like is used as the refrigerant that circulates in the refrigerant circuit 16.
- the indoor unit 10 of the air conditioner 100 is installed, for example, by being hooked to a wall surface in a room or by being embedded in or hung from the ceiling in a room.
- the indoor unit 10 is connected to the outdoor unit 20 via the refrigerant connection pipe 15 and constitutes part of the refrigerant circuit 16.
- the indoor unit 10 includes an indoor fan 11 and an indoor heat exchanger 12.
- the outdoor unit 20 is installed outside.
- the outdoor unit 20 is connected to the indoor unit 10 via the refrigerant connection pipe 15 and constitutes part of the refrigerant circuit 16.
- the outdoor unit 20 includes an outdoor fan 21, an outdoor heat exchanger 22, a compressor 23, a four-way switching valve 24, and an outdoor expansion valve 25 as an expansion mechanism.
- the refrigerant connection pipe 15 is a refrigerant pipe that is constructed on site when the air conditioner 100 is installed at an installation site.
- the refrigerant connection pipe 15 is connected to the indoor unit 10 and the outdoor unit 20 and constitutes the refrigerant circuit 16.
- the refrigerant amount determination unit 30 determines the amount of the refrigerant included in the refrigerant circuit 16. Details of the refrigerant amount determination unit 30 will be described later.
- the outdoor unit 20 filled with a predetermined amount of the refrigerant in advance and the indoor unit 10 are installed, and the refrigerant connection pipe 15 is connected to constitute the refrigerant circuit 16, and then, the refrigerant circuit 16 is additionally filled with the refrigerant that has been insufficient, in accordance with the length of the refrigerant connection pipe 15, to set a state in which a prescribed amount of the refrigerant is included.
- the air conditioner 100 performs a cooling operation in which the refrigerant sequentially flows in the compressor 23, the outdoor heat exchanger 22, the outdoor expansion valve 25, and the indoor heat exchanger 12 or performs a heating operation in which refrigerant sequentially flows in the compressor 23, the indoor heat exchanger 12, the outdoor expansion valve 25, and the outdoor heat exchanger 22.
- the four-way switching valve 24 is switched to an outdoor heat release state (state indicated by the solid line in Fig. 1 ).
- a gaseous refrigerant at a low pressure in the refrigeration cycle is sucked into the compressor 23 and is compressed to a high pressure in the refrigeration cycle before being discharged.
- the high-pressure gaseous refrigerant is discharged from the compressor 23 and is sent through the four-way switching valve 24 to the outdoor heat exchanger 22.
- the high-pressure gaseous refrigerant sent to the outdoor heat exchanger 22 is subjected to heat exchange with outdoor air supplied from the outdoor fan 21 and becomes a high-pressure liquid refrigerant.
- the outdoor heat exchanger 22 functions as a condenser.
- the high-pressure liquid refrigerant releases heat in the outdoor heat exchanger 22 and is decompressed by the outdoor expansion valve 25 to the low pressure in the refrigeration cycle to become a low-pressure refrigerant in a gas-liquid two-phase state.
- the low-pressure refrigerant in a gas-liquid two-phase state decompressed by the outdoor expansion valve 25 is sent to the indoor heat exchanger 12.
- the low-pressure refrigerant in a gas-liquid two-phase state sent to the indoor heat exchanger 12 is subjected to heat exchange in the indoor heat exchanger 12 with indoor air supplied from the indoor fan 11 to be evaporated.
- indoor air is cooled, and indoor cooling is performed.
- the indoor heat exchanger 12 functions as an evaporator.
- the low-pressure gaseous refrigerant evaporated in the indoor heat exchanger 12 passes through the four-way switching valve 24 and is sucked into the compressor 23 again.
- the four-way switching valve 24 is switched to an outdoor evaporation state (state indicated by the broken line in Fig. 1 ).
- a gaseous refrigerant at a low pressure in the refrigeration cycle is sucked into the compressor 23 and is compressed to a high pressure in the refrigeration cycle before being discharged.
- the high-pressure gaseous refrigerant is discharged from the compressor 23 and is sent through the four-way switching valve 24 to the indoor heat exchanger 12.
- the high-pressure gaseous refrigerant sent to the indoor heat exchanger 12 is subjected to heat exchange in the indoor heat exchanger 12 with indoor air supplied from the indoor fan 11 and become a high-pressure liquid refrigerant.
- the indoor heat exchanger 12 functions as a condenser.
- the high-pressure liquid refrigerant releases heat in the indoor heat exchanger 12 and is sent to the outdoor expansion valve 25.
- the refrigerant sent to the outdoor expansion valve 25 is decompressed by the outdoor expansion valve 25 to the low pressure in the refrigeration cycle to become a low-pressure refrigerant in a gas-liquid two-phase state.
- the low-pressure refrigerant in a gas-liquid two-phase state decompressed by the outdoor expansion valve 25 is sent to the outdoor heat exchanger 22.
- the low-pressure refrigerant in a gas-liquid two-phase state sent to the outdoor heat exchanger 22 is subjected to heat exchange in the outdoor heat exchanger 22 functioning as an evaporator for the refrigerant with outdoor air supplied from the outdoor fan 21 to be evaporated and becomes a low-pressure gaseous refrigerant.
- the low-pressure gaseous refrigerant evaporated in the outdoor heat exchanger 22 passes through the four-way switching valve 24 and is sucked into the compressor 23 again.
- the refrigerant amount determination unit 30 includes a detection unit 31, a storage unit 32, a correction unit 33, a determination unit 34, and a notification unit 35.
- the detection unit 31 includes an air temperature sensor 36, a condensation temperature sensor 37, and an acquisition unit 38.
- the air temperature sensor 36 detects an air temperature that is the temperature of outdoor air that flows into the outdoor heat exchanger 22.
- the condensation temperature sensor 37 detects the condensation temperature of the refrigerant.
- the condensation temperature sensor 37 is provided so as to be in contact with a heat exchanger tube (not illustrated) included in the outdoor heat exchanger 22.
- the acquisition unit 38 acquires a temperature difference between the air temperature detected by the air temperature sensor 36 and the condensation temperature detected by the condensation temperature sensor 37.
- the storage unit 32 stores the air temperature detected by the air temperature sensor 36, the condensation temperature detected by the condensation temperature sensor 37, and the temperature difference acquired by the acquisition unit 38.
- the correction unit 33 corrects the temperature difference by using the air temperature stored in the storage unit 32.
- the determination unit 34 compares a plurality of temperature differences acquired by the acquisition unit 38 and determines a change in the amount of the refrigerant included in the refrigerant circuit 16.
- the notification unit 35 notifies insufficiency of the amount of the refrigerant.
- the notification unit 35 notifies insufficiency of the amount of the refrigerant by using, for example, an LED or the like.
- the amount of the refrigerant is determined in a first step ST1, a second step ST2, and a third step ST3 in this order.
- step S101 to step S104 are performed.
- step S105 to step S109 are performed.
- step S110 and step S111 are performed.
- Fig. 3 is a flowchart illustrating operations of the air conditioner 100 in the first step ST1.
- the air conditioner 100 is installed on site in a state in which a prescribed amount of the refrigerant is included.
- the time at which the air conditioner 100 is installed is a first timing T1.
- step S101 the air conditioner 100 starts a test run for detecting the air temperature and the condensation temperature.
- step S102 the air conditioner 100 performs control such that the frequency of the compressor 23 becomes a predetermined value so as to set a state in which the frequency of the compressor 23 is stabilized.
- the air temperature sensor 36 of the detection unit 31 detects a first air temperature Ta1, and the condensation temperature sensor 37 detects a first condensation temperature Tc1.
- the first air temperature Ta1 is the air temperature at the first timing T1
- the first condensation temperature Tc1 is the condensation temperature at the first timing T1.
- the storage unit 32 stores the first air temperature Ta1 and the first condensation temperature Tc1 that are detected.
- the acquisition unit 38 compares the first air temperature Ta1 and the first condensation temperature Tc1 with each other, thereby acquiring a first temperature difference ⁇ T1, which is a temperature difference at the first timing T1.
- the acquired first temperature difference ⁇ T1 is stored in the storage unit 32.
- step ST2 and the third step ST3 which are illustrated in Fig. 4 , will be described.
- the second step ST2 and the third step ST3 are performed after a certain period has elapsed from the first timing T1.
- the second step ST2 and the third step ST3 are performed at the time of maintenance after a period of about one year has elapsed from the first timing T1. This time of maintenance is a second timing T2.
- step S105 the air conditioner 100 starts a test run as in step S101.
- step S106 control is performed such that the frequency of the compressor 23 becomes a predetermined value so as to set a state in which the frequency of the compressor 23 is stabilized.
- step S107 the air temperature sensor 36 of the detection unit 31 detects a second air temperature Ta2, and the condensation temperature sensor 37 detects a second condensation temperature Tc2.
- the second air temperature Ta2 is the air temperature at the second timing T2
- the second condensation temperature Tc2 is the condensation temperature at the second timing T2.
- the storage unit 32 stores the second air temperature Ta2 and the second condensation temperature Tc2 that are detected.
- the acquisition unit 38 compares the second air temperature Ta2 and the second condensation temperature Tc2 with each other and acquires a second temperature difference ⁇ T2, which is a temperature difference at the second timing T2.
- the acquired second temperature difference ⁇ T2 is stored in the storage unit 32.
- step S109 the correction unit 33 corrects the first temperature difference ⁇ T1 and the second temperature difference ⁇ T2 by using a difference between the first air temperature Ta1 and the second air temperature Ta2 stored in the storage unit 32.
- the method for correction performed by the correction unit 33 will be described later.
- step S110 the determination unit 34 compares the corrected first temperature difference ⁇ T1 and the corrected second temperature difference ⁇ T2 with each other, and, if the temperature difference is 3°C or more, determines that the refrigerant leaks to the outside and that the amount of the refrigerant is insufficient.
- step Sill the notification unit 35 notifies to an operator that the amount of the refrigerant is insufficient.
- Fig. 5 is a P-H chart obtained by experiment in which the amount of the refrigerant to be included in the air conditioner 100 is changed in a case in which the first air temperature Ta1 and the second air temperature Ta2 are at 35°C. It is found that the condensation temperature is lower in the air conditioner 100 in which the amount of the refrigerant is insufficient compared with the air conditioner 100 filled with a prescribed amount of the refrigerant. If the refrigerant included in the air conditioner 100 leaks by 20% from the prescribed amount, the first temperature difference ⁇ T1 and the second temperature difference ⁇ T2 diverges from each other by 3°C, and the performance efficiency of the air conditioner 100 decreases by 10%.
- the present inventors have found that, if the first temperature difference ⁇ T1 and the second temperature difference ⁇ T2 are compared with each other, and if the temperature difference diverges by 2°C to 4°C or more, it can be determined that the refrigerant leaks to the outside and that the amount of the refrigerant is insufficient.
- the performance efficiency of the air conditioner 100 decreases by 9.4%. Furthermore, if the first air temperature Ta1 and the second air temperature Ta2 are at 45°C, and if the refrigerant included in the air conditioner 100 leaks by 20% from the prescribed amount, the performance efficiency of the air conditioner 100 decreases by 10.6%.
- the correction unit 33 corrects the first temperature difference ⁇ Ta1 by +0.4°C by using an air temperature of 25 °C as a reference temperature. If the difference between the first air temperature Ta1 and the second air temperature Ta2 corrected by the correction unit 33 diverges by 3°C or more, the determination unit 34 determines that the amount of the refrigerant is insufficient.
- the correction unit 33 may correct either one of the first temperature difference ⁇ T1 or the second temperature difference ⁇ T2 or may correct each of the first temperature difference ⁇ T1 and the second temperature difference ⁇ T2.
- the threshold used as a reference for determining the amount of the refrigerant may be corrected.
- a correction may also be made in accordance with a difference between the air temperature as a reference and each of the first air temperature Ta1 and the second air temperature Ta2.
- the air conditioner 100 as a refrigeration cycle apparatus includes the indoor unit 10, the outdoor unit 20, the refrigerant connection pipe 15 that connects the indoor unit 10 and the outdoor unit 20, and the refrigerant amount determination unit 30 that determines the amount of the refrigerant that flows in the refrigerant circuit 16.
- the refrigerant circuit 16 of the air conditioner 100 is constituted by the indoor unit 10 and the outdoor unit 20 being connected via the refrigerant connection pipe 15.
- the refrigerant amount determination unit 30 includes the detection unit 31, the storage unit 32, the correction unit 33, the determination unit 34, and the notification unit 35.
- the detection unit 31 includes the air temperature sensor 36, the condensation temperature sensor 37, and the acquisition unit 38.
- the air temperature sensor 36 detects the air temperature that is the temperature of air that flows into the outdoor heat exchanger 22 as a condenser.
- the condensation temperature sensor 37 detects the condensation temperature of the refrigerant that flows in the outdoor heat exchanger 22.
- the acquisition unit 38 acquires a temperature difference between the air temperature and the condensation temperature.
- the determination unit 34 compares the first temperature difference ⁇ T1 and the second temperature difference ⁇ T2 with each other, thereby determining the amount of the refrigerant included in the refrigerant circuit 16.
- the first temperature difference ⁇ T1 is a temperature difference acquired by the acquisition unit 38 at the first timing T1 when the air conditioner 100 is installed.
- the second temperature difference ⁇ T2 is a temperature difference acquired by the acquisition unit 38 at the second timing T2 after a certain period has elapsed from the first timing T1.
- the condensation temperature decreases.
- the amount of the refrigerant included in the refrigerant circuit 16 can be determined, and it can be determined whether the refrigerant leaks from the refrigerant circuit 16 to the outside by accidental means.
- the threshold used by the determination unit 34 to determine that the amount of the refrigerant is insufficient is 2°C to 4°C. If the difference between the first temperature difference ⁇ T1 and the second temperature difference ⁇ T2 is from 2°C to 4°C or more, by determining that the amount of the refrigerant is insufficient, the determination unit 34 can determine whether the refrigerant leaks from the refrigerant circuit 16 to the outside by accidental means.
- the notification unit 35 notifies the insufficiency of the amount of the refrigerant. Thus, an operator who determines the amount of the refrigerant can notice the insufficiency of the amount of the refrigerant.
- the correction unit 33 corrects the temperature differences by using the air temperature stored in the storage unit 32. By the correction made by the correction unit 33, the amount of the refrigerant is not necessarily determined under the same conditions as those at the first timing T1. This enables the operator to determine the amount of the refrigerant at any time.
- the first timing T1 may be the time of initial operation of the air conditioner 100 or the time of maintenance of the air conditioner 100.
- the second timing T2 is a maintenance timing at or after the maintenance performed at the first timing T1.
- the correction unit 33 may make a correction by using the evaporation temperature of the refrigerant.
- the air conditioner 100 includes an evaporation temperature sensor that detects the evaporation temperature of the refrigerant.
- the performance efficiency decreases by 9.4%. If the evaporation temperature increases by 5°C, the performance efficiency decreases by 10.6%.
- the difference between the first temperature difference ⁇ T1 and the second temperature difference ⁇ T2 is corrected by +0.2°C. In contrast, when the evaporation temperature increases by 5°C, the temperature between the first temperature difference ⁇ T1 and the second temperature difference ⁇ T2 is corrected by -0.2°C.
- the difference between the first temperature difference ⁇ T1 and the second temperature difference ⁇ T2 is corrected by +0.4°C.
- the difference between the first temperature difference ⁇ T1 and the second temperature difference ⁇ T2 is corrected by -0.4°C.
- the correction unit 33 in the determination of the amount of the refrigerant, does not necessarily make a correction.
- the air conditioner 100 can determine the amount of the refrigerant without correction.
- the storage unit 32 does not necessarily store the first temperature difference ⁇ T1 and the second temperature difference ⁇ T2.
- the air conditioner 100 may acquire the first temperature difference ⁇ T1 as necessary from the first air temperature Ta1 and the first condensation temperature Tc1 stored in the storage unit 32, and the determination unit 34 may compare the acquired first temperature difference ⁇ T1 and the second temperature difference ⁇ T2 with each other.
- the air temperature detected by the air temperature sensor 36 may be the temperature of outdoor air around installation site of the outdoor unit 20.
- the air temperature sensor 36 may be a sensor that detects the air temperature around the outdoor unit 20.
- the storage unit 32, the correction unit 33, the determination unit 34, and the acquisition unit 38 may alternatively be included in a server 150 connected to the air conditioner 100 via the Internet 39.
- the detected air temperature and condensation temperature are transmitted to the server 150.
- the storage unit 32, the correction unit 33, the determination unit 34, and the acquisition unit 38 in the server 150 performs substantially the same operations as those in the refrigerant amount determination method according to the first embodiment.
- the refrigerant amount determination system 200 is a system that determines the amount of a refrigerant included in a refrigeration cycle apparatus.
- an air conditioner 300 is used as the refrigeration cycle apparatus.
- Fig. 7 schematically illustrates the air conditioner 300 according to this embodiment.
- the air conditioner 300 performs indoor cooling and heating for buildings or the like by performing a vapor compression refrigeration cycle.
- the air conditioner 300 mainly includes an indoor unit 310, an outdoor unit 320, and a refrigerant connection pipe that connects the indoor unit 310 and the outdoor unit 320.
- a refrigerant circuit of the air conditioner 300 is constituted by the indoor unit 310 and the outdoor unit 320 being connected via the refrigerant connection pipe.
- the indoor unit 310 of the air conditioner 300 is installed, for example, by being hooked to a wall surface in a room or by being embedded in or hung from the ceiling in a room.
- the indoor unit 310 is connected to the outdoor unit 320 via the refrigerant connection pipe and constitutes part of the refrigerant circuit.
- the indoor unit 310 includes an indoor fan 311 and an indoor heat exchanger 312.
- the outdoor unit 320 is installed outside.
- the outdoor unit 320 is connected to the indoor unit 310 via the refrigerant connection pipe and constitutes part of the refrigerant circuit.
- the outdoor unit 320 includes an outdoor fan 321, an outdoor heat exchanger 322, a compressor 323, a four-way switching valve 324, and an outdoor expansion valve 325 as an expansion mechanism.
- the refrigerant connection pipe is a refrigerant pipe that is constructed on site when the air conditioner 300 is installed at an installation site.
- the refrigerant connection pipe is connected to the indoor unit 310 and the outdoor unit 320 and constitutes the refrigerant circuit. Operations of the air conditioner 300 are substantially the same as those of the air conditioner 100 according to the first embodiment and thus will be omitted.
- the refrigerant amount determination system 200 is a retrofitted unit that is placed separately from the air conditioner 300.
- the refrigerant amount determination system 200 includes a detection unit 231, a storage unit 232, a correction unit 233, a determination unit 234, and a notification unit 235.
- the detection unit 231 includes an air temperature sensor 236, a condensation temperature sensor 237, and an acquisition unit 238.
- the air temperature sensor 236 detects an air temperature that is the temperature of outdoor air that flows into the outdoor heat exchanger 322.
- the condensation temperature sensor 237 detects the condensation temperature of the refrigerant.
- the condensation temperature sensor 237 is provided so as to be in contact with a heat exchanger tube (not illustrated) included in the outdoor heat exchanger 322 of the air conditioner 300.
- the acquisition unit 238 acquires a temperature difference between the air temperature detected by the air temperature sensor 236 and the condensation temperature detected by the condensation temperature sensor 237.
- the storage unit 232 stores the air temperature detected by the air temperature sensor 236 and the temperature difference acquired by the acquisition unit 238.
- the correction unit 233 corrects the temperature difference by using the air temperature stored in the storage unit 232.
- the determination unit 234 compares a plurality of temperature differences acquired by the acquisition unit 238 and determines a change in the amount of the refrigerant included in the refrigerant circuit.
- the notification unit 235 notifies insufficiency of the amount of the refrigerant.
- the notification unit 235 notifies insufficiency of the amount of the refrigerant by using, for example, an LED or the like.
- the amount of the refrigerant is determined in a first step ST1, a second step ST2, and a third step ST3 in this order.
- step S201 to step S204 are performed.
- step S205 to step S209 are performed.
- step S210 and step S211 are performed.
- step S will be described below. Note that substantially the same operations as those of the air conditioner 100 according to the first embodiment will be omitted from the description.
- Fig. 8 is a flowchart illustrating operations of the air conditioner 300 and the refrigerant amount determination system 200 in the first step ST1.
- the air conditioner 300 is installed on site in a state in which a prescribed amount of the refrigerant is included.
- the time at which the air conditioner 300 is installed is a first timing T1.
- Operations in step S201 to step S204 are substantially the same as operations in step S101 to step S104 in the first embodiment.
- the second step ST2 is performed at the time of maintenance after a certain period has elapsed from the first timing T1.
- Step S205 is performed at the time of maintenance after a certain period has elapsed from the first timing T1. This time of maintenance is a second timing T2.
- Step S205 to step S211 are substantially the same as operations in step S205 to step S211 in the first embodiment below.
- the basis for determining the insufficiency of the amount of the refrigerant is substantially the same as that in the first embodiment and thus will be omitted.
- the refrigerant amount determination system 200 includes the detection unit 231, the storage unit 232, the correction unit 233, the determination unit 234, and the notification unit 235.
- the detection unit 231 includes the air temperature sensor 236, the condensation temperature sensor 237, and the acquisition unit 238.
- the air temperature sensor 236 detects the air temperature that is the temperature of air that flows into the outdoor heat exchanger 322 as a condenser.
- the condensation temperature sensor 237 detects the condensation temperature of the refrigerant that flows in the outdoor heat exchanger 322.
- the acquisition unit 238 acquires a temperature difference between the air temperature and the condensation temperature.
- the determination unit 234 compares a first temperature difference ⁇ T1 and a second temperature difference ⁇ T2 with each other, thereby determining the amount of the refrigerant included in the refrigerant circuit.
- the first temperature difference ⁇ T1 is a temperature difference acquired by the acquisition unit 238 at the first timing T1 when the air conditioner 300 is installed.
- the second temperature difference ⁇ T2 is a temperature difference acquired by the acquisition unit 238 at the second timing T2 after a certain period has elapsed from the first timing T1.
- the condensation temperature decreases.
- the amount of the refrigerant included in the refrigerant circuit can be determined, and it can be determined whether the refrigerant leaks from the refrigerant circuit to the outside by accidental means.
- the threshold used by the determination unit 234 to determine that the amount of the refrigerant is insufficient is 2°C to 4°C. If the difference between the first temperature difference ⁇ T1 and the second temperature difference ⁇ T2 is from 2°C to 4°C or more, by determining that the amount of the refrigerant is insufficient, the determination unit 234 can determine whether the refrigerant leaks from the refrigerant circuit to the outside by accidental means.
- the notification unit 235 notifies the insufficiency of the amount of the refrigerant. Thus, an operator who determines the amount of the refrigerant can notice the insufficiency of the amount of the refrigerant.
- the correction unit 233 corrects the temperature differences by using the air temperature stored in the storage unit 232.
- the amount of the refrigerant is not necessarily determined under the same conditions as those at the first timing T1. This enables the operator to determine the amount of the refrigerant at any time.
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Abstract
Description
- The present disclosure relates to a refrigeration cycle apparatus, a refrigerant amount determination system, and a refrigerant amount determination method.
- Conventionally, a refrigeration cycle apparatus that determines the amount of a refrigerant included in a refrigerant circuit has been known. For example, PTL 1 (
Japanese Unexamined Patent Application Publication No. H6-159869 - The technique in
PTL 1 is incapable of grasping a decrease in the amount of the refrigerant from an initial amount of the refrigerant, and the determination of the amount of the refrigerant is insufficient for the purpose other than protection of the compressor. - In a refrigeration cycle apparatus according to a first aspect, a refrigerant circulates in a refrigerant circuit constituted by a compressor, a condenser, an expansion mechanism, and an evaporator being connected. The refrigeration cycle apparatus includes an air temperature sensor, a condensation temperature sensor, an acquisition unit, and a determination unit. The air temperature sensor detects an air temperature, which is a temperature of air that flows into the condenser. The condensation temperature sensor detects a condensation temperature of the refrigerant that flows through the condenser. The acquisition unit acquires a temperature difference between the air temperature and the condensation temperature. The determination unit determines an amount of the refrigerant included in the refrigerant circuit by comparing a first temperature difference and a second temperature difference with each other. The first temperature difference is a temperature difference acquired by the acquisition unit at a first timing. The second temperature difference is a temperature difference acquired by the acquisition unit at a second timing.
- The refrigeration cycle apparatus herein compares the first temperature difference and the second temperature difference with each other and determines the amount of the refrigerant included in the refrigerant circuit. Thus, it can be determined whether the refrigerant leaks from the refrigerant circuit to the outside by accidental means.
- A refrigeration cycle apparatus according to a second aspect is the refrigeration cycle apparatus according to the first aspect further including a storage unit. The storage unit stores at least one of the first temperature difference or the air temperature and the condensation temperature acquired at the first timing.
- A refrigeration cycle apparatus according to a third aspect is the refrigeration cycle apparatus according to the first or second aspect, in which the first timing is any of a time at which the refrigeration cycle apparatus is installed, at a time of initial operation of the refrigeration cycle apparatus, or a time of maintenance of the refrigeration cycle apparatus.
- A refrigeration cycle apparatus according to a fourth aspect is the refrigeration cycle apparatus according to any of the first to third aspects, in which, if a difference between the first temperature difference and the second temperature difference is greater than or equal to a threshold that is any value from 2°C to 4°C, the determination unit determines that the amount of the refrigerant included in the refrigerant circuit is insufficient.
- A refrigeration cycle apparatus according to a fifth aspect is the refrigeration cycle apparatus according to any of the first to fourth aspects, further including a notification unit that notifies insufficiency of the amount of the refrigerant if the determination unit determines that the amount of the refrigerant is insufficient.
- A refrigeration cycle apparatus according to a sixth aspect is the refrigeration cycle apparatus according to any of the first to fifth aspects, further including a correction unit that corrects the first temperature difference and the second temperature difference by using at least either one of the air temperature or an evaporation temperature of the refrigerant.
- A refrigerant amount determination system according to a seventh aspect is a refrigerant amount determination system that determines an amount of a refrigerant included in a refrigeration cycle apparatus. In the refrigeration cycle apparatus, the refrigerant circulates in a refrigerant circuit constituted by a compressor, a condenser, an expansion mechanism, and an evaporator being connected. The refrigerant amount determination system includes an air temperature sensor, a condensation temperature sensor, an acquisition unit, and a determination unit. The air temperature sensor detects an air temperature, which is a temperature of air that flows into the condenser. The condensation temperature sensor detects a condensation temperature of the refrigerant that flows through the condenser. The acquisition unit acquires a temperature difference between the air temperature and the condensation temperature. The determination unit determines the amount of the refrigerant included in the refrigerant circuit by comparing a first temperature difference and a second temperature difference with each other. The first temperature difference is a temperature difference acquired by the acquisition unit at a first timing. The second temperature difference is a temperature difference acquired by the acquisition unit at a second timing.
- The refrigeration cycle apparatus herein compares the first temperature difference and the second temperature difference with each other and determines the amount of the refrigerant included in the refrigerant circuit. Thus, it can be determined whether the refrigerant leaks from the refrigerant circuit to the outside by accidental means.
- A refrigerant amount determination system according to an eighth aspect is the refrigerant amount determination system according to the seventh aspect further including a storage unit. The storage unit stores at least one of the first temperature difference or the air temperature and the condensation temperature acquired at the first timing.
- A refrigerant amount determination system according to a ninth aspect is the refrigerant amount determination system according to the seventh or eighth aspect, in which the first timing is any of a time at which the refrigeration cycle apparatus is installed, at a time of initial operation of the refrigeration cycle apparatus, or a time of maintenance of the refrigeration cycle apparatus.
- A refrigerant amount determination system according to a tenth aspect is the refrigerant amount determination system according to any of the seventh to ninth aspects, in which, if a difference between the first temperature difference and the second temperature difference is greater than or equal to a threshold that is any value from 2°C to 4°C, the determination unit determines that the amount of the refrigerant included in the refrigerant circuit is insufficient.
- A refrigerant amount determination system according to an eleventh aspect is the refrigerant amount determination system according to any of the seventh to tenth aspects further including a notification unit that notifies insufficiency of the amount of the refrigerant if the determination unit determines that the amount of the refrigerant is insufficient.
- A refrigerant amount determination system according to a twelfth aspect is the refrigerant amount determination system according to any of the seventh to eleventh aspects further including a correction unit that corrects the first temperature difference and the second temperature difference by using the air temperature or an evaporation temperature of the refrigerant.
- A refrigerant amount determination method according to a thirteenth aspect is a refrigerant amount determination method for determining an amount of a refrigerant included in a refrigeration cycle apparatus. In the refrigeration cycle apparatus, the refrigerant circulates in a refrigerant circuit constituted by a compressor, a condenser, an expansion mechanism, and an evaporator being connected. The refrigerant amount determination method includes a first step, a second step, and a third step. In the first step, a first temperature difference is acquired. The first temperature difference is a temperature difference detected at a first timing, between an air temperature and a condensation temperature, the air temperature being a temperature of air that flows into the condenser, the condensation temperature being a condensation temperature of the refrigerant that flows through the condenser. In the second step, a second temperature difference is acquired. The second temperature difference is a temperature difference detected at a second timing, between the air temperature and the condensation temperature, the air temperature being a temperature of air that flows into the condenser, the condensation temperature being a condensation temperature of the refrigerant that flows through the condenser. In the third step, a change in the amount of the refrigerant included in the refrigerant circuit is determined by comparing the first temperature difference and the second temperature difference with each other.
-
- <
Fig. 1 >Fig. 1 schematically illustrates an air conditioner according to a first embodiment. - <
Fig. 2 >Fig. 2 is a block diagram of a refrigeration cycle apparatus according to the first embodiment. - <
Fig. 3 >Fig. 3 is a flowchart illustrating operations of the refrigeration cycle apparatus in a first step. - <
Fig. 4 >Fig. 4 is a flowchart illustrating operations of the refrigeration cycle apparatus in a second step and a third step. - <
Fig. 5 >Fig. 5 is a P-H chart regarding a relationship between the amount of a refrigerant and an air temperature. - <
Fig. 6 >Fig. 6 is a block diagram of Modification 6 according to the first embodiment. - <
Fig. 7 >Fig. 7 is a block diagram of a refrigeration cycle apparatus according to a second embodiment. - <
Fig. 8 >Fig. 8 is a flowchart illustrating operations of the refrigeration cycle apparatus and a refrigerant amount determination system in a first step. - <
Fig. 9 >Fig. 9 is a flowchart illustrating operations of the air conditioner and the refrigerant amount determination system in a second step and a third step. - Now, an embodiment of an
air conditioner 100 as a refrigeration cycle apparatus according to a first embodiment will be described. -
Fig. 1 schematically illustrates theair conditioner 100 according to this embodiment. Theair conditioner 100 performs indoor cooling and heating for buildings or the like by performing a vapor compression refrigeration cycle. Theair conditioner 100 mainly includes anindoor unit 10, anoutdoor unit 20, arefrigerant connection pipe 15 that connects theindoor unit 10 and theoutdoor unit 20, and a refrigerantamount determination unit 30 that determines the amount of a refrigerant that flows through arefrigerant circuit 16. Therefrigerant circuit 16 of theair conditioner 100 is constituted by theindoor unit 10 and theoutdoor unit 20 being connected via therefrigerant connection pipe 15. As the refrigerant that circulates in therefrigerant circuit 16, R410A, R32, R407C, R22, R134a, carbon dioxide, or the like is used. - The
indoor unit 10 of theair conditioner 100 is installed, for example, by being hooked to a wall surface in a room or by being embedded in or hung from the ceiling in a room. Theindoor unit 10 is connected to theoutdoor unit 20 via therefrigerant connection pipe 15 and constitutes part of therefrigerant circuit 16. Theindoor unit 10 includes anindoor fan 11 and anindoor heat exchanger 12. - The
outdoor unit 20 is installed outside. Theoutdoor unit 20 is connected to theindoor unit 10 via therefrigerant connection pipe 15 and constitutes part of therefrigerant circuit 16. Theoutdoor unit 20 includes anoutdoor fan 21, anoutdoor heat exchanger 22, acompressor 23, a four-way switching valve 24, and anoutdoor expansion valve 25 as an expansion mechanism. - The
refrigerant connection pipe 15 is a refrigerant pipe that is constructed on site when theair conditioner 100 is installed at an installation site. Therefrigerant connection pipe 15 is connected to theindoor unit 10 and theoutdoor unit 20 and constitutes therefrigerant circuit 16. - The refrigerant
amount determination unit 30 determines the amount of the refrigerant included in therefrigerant circuit 16. Details of the refrigerantamount determination unit 30 will be described later. - When the
air conditioner 100 according to this embodiment is installed on site, theoutdoor unit 20 filled with a predetermined amount of the refrigerant in advance and theindoor unit 10 are installed, and therefrigerant connection pipe 15 is connected to constitute therefrigerant circuit 16, and then, therefrigerant circuit 16 is additionally filled with the refrigerant that has been insufficient, in accordance with the length of therefrigerant connection pipe 15, to set a state in which a prescribed amount of the refrigerant is included. - Next, operations of the
air conditioner 100 will be described. Theair conditioner 100 performs a cooling operation in which the refrigerant sequentially flows in thecompressor 23, theoutdoor heat exchanger 22, theoutdoor expansion valve 25, and theindoor heat exchanger 12 or performs a heating operation in which refrigerant sequentially flows in thecompressor 23, theindoor heat exchanger 12, theoutdoor expansion valve 25, and theoutdoor heat exchanger 22. - During a cooling operation, the four-
way switching valve 24 is switched to an outdoor heat release state (state indicated by the solid line inFig. 1 ). In therefrigerant circuit 16, a gaseous refrigerant at a low pressure in the refrigeration cycle is sucked into thecompressor 23 and is compressed to a high pressure in the refrigeration cycle before being discharged. The high-pressure gaseous refrigerant is discharged from thecompressor 23 and is sent through the four-way switching valve 24 to theoutdoor heat exchanger 22. The high-pressure gaseous refrigerant sent to theoutdoor heat exchanger 22 is subjected to heat exchange with outdoor air supplied from theoutdoor fan 21 and becomes a high-pressure liquid refrigerant. At this time, theoutdoor heat exchanger 22 functions as a condenser. The high-pressure liquid refrigerant releases heat in theoutdoor heat exchanger 22 and is decompressed by theoutdoor expansion valve 25 to the low pressure in the refrigeration cycle to become a low-pressure refrigerant in a gas-liquid two-phase state. The low-pressure refrigerant in a gas-liquid two-phase state decompressed by theoutdoor expansion valve 25 is sent to theindoor heat exchanger 12. The low-pressure refrigerant in a gas-liquid two-phase state sent to theindoor heat exchanger 12 is subjected to heat exchange in theindoor heat exchanger 12 with indoor air supplied from theindoor fan 11 to be evaporated. Thus, indoor air is cooled, and indoor cooling is performed. At this time, theindoor heat exchanger 12 functions as an evaporator. The low-pressure gaseous refrigerant evaporated in theindoor heat exchanger 12 passes through the four-way switching valve 24 and is sucked into thecompressor 23 again. - During a heating operation, the four-
way switching valve 24 is switched to an outdoor evaporation state (state indicated by the broken line inFig. 1 ). In therefrigerant circuit 16, a gaseous refrigerant at a low pressure in the refrigeration cycle is sucked into thecompressor 23 and is compressed to a high pressure in the refrigeration cycle before being discharged. The high-pressure gaseous refrigerant is discharged from thecompressor 23 and is sent through the four-way switching valve 24 to theindoor heat exchanger 12. The high-pressure gaseous refrigerant sent to theindoor heat exchanger 12 is subjected to heat exchange in theindoor heat exchanger 12 with indoor air supplied from theindoor fan 11 and become a high-pressure liquid refrigerant. Thus, indoor air is heated, and indoor heating is performed. At this time, theindoor heat exchanger 12 functions as a condenser. The high-pressure liquid refrigerant releases heat in theindoor heat exchanger 12 and is sent to theoutdoor expansion valve 25. The refrigerant sent to theoutdoor expansion valve 25 is decompressed by theoutdoor expansion valve 25 to the low pressure in the refrigeration cycle to become a low-pressure refrigerant in a gas-liquid two-phase state. The low-pressure refrigerant in a gas-liquid two-phase state decompressed by theoutdoor expansion valve 25 is sent to theoutdoor heat exchanger 22. The low-pressure refrigerant in a gas-liquid two-phase state sent to theoutdoor heat exchanger 22 is subjected to heat exchange in theoutdoor heat exchanger 22 functioning as an evaporator for the refrigerant with outdoor air supplied from theoutdoor fan 21 to be evaporated and becomes a low-pressure gaseous refrigerant. The low-pressure gaseous refrigerant evaporated in theoutdoor heat exchanger 22 passes through the four-way switching valve 24 and is sucked into thecompressor 23 again. - A detailed configuration of the refrigerant
amount determination unit 30 illustrated inFig. 2 will be described. The refrigerantamount determination unit 30 includes adetection unit 31, astorage unit 32, acorrection unit 33, adetermination unit 34, and anotification unit 35. - The
detection unit 31 includes anair temperature sensor 36, acondensation temperature sensor 37, and anacquisition unit 38. Theair temperature sensor 36 detects an air temperature that is the temperature of outdoor air that flows into theoutdoor heat exchanger 22. Thecondensation temperature sensor 37 detects the condensation temperature of the refrigerant. For example, thecondensation temperature sensor 37 is provided so as to be in contact with a heat exchanger tube (not illustrated) included in theoutdoor heat exchanger 22. Theacquisition unit 38 acquires a temperature difference between the air temperature detected by theair temperature sensor 36 and the condensation temperature detected by thecondensation temperature sensor 37. - The
storage unit 32 stores the air temperature detected by theair temperature sensor 36, the condensation temperature detected by thecondensation temperature sensor 37, and the temperature difference acquired by theacquisition unit 38. - The
correction unit 33 corrects the temperature difference by using the air temperature stored in thestorage unit 32. - The
determination unit 34 compares a plurality of temperature differences acquired by theacquisition unit 38 and determines a change in the amount of the refrigerant included in therefrigerant circuit 16. - If the
determination unit 34 determines that the amount of the refrigerant is insufficient, thenotification unit 35 notifies insufficiency of the amount of the refrigerant. Thenotification unit 35 notifies insufficiency of the amount of the refrigerant by using, for example, an LED or the like. - Next, a method for determining the amount of the refrigerant will be described with reference to
Fig. 3 and Fig. 4 . Note that, in a case described below, for example, regular inspection is performed for determining whether the refrigerant leaks from therefrigerant circuit 16 to the outside by accidental means. - The amount of the refrigerant is determined in a first step ST1, a second step ST2, and a third step ST3 in this order. In the first step ST1, step S101 to step S104 are performed. In the second step ST2, step S105 to step S109 are performed. In the third step ST3, step S110 and step S111 are performed. Each step will be described below.
-
Fig. 3 is a flowchart illustrating operations of theair conditioner 100 in the first step ST1. Theair conditioner 100 is installed on site in a state in which a prescribed amount of the refrigerant is included. The time at which theair conditioner 100 is installed is a first timing T1. In step S101, theair conditioner 100 starts a test run for detecting the air temperature and the condensation temperature. In step S102, theair conditioner 100 performs control such that the frequency of thecompressor 23 becomes a predetermined value so as to set a state in which the frequency of thecompressor 23 is stabilized. In step S103, theair temperature sensor 36 of thedetection unit 31 detects a first air temperature Ta1, and thecondensation temperature sensor 37 detects a first condensation temperature Tc1. The first air temperature Ta1 is the air temperature at the first timing T1, and the first condensation temperature Tc1 is the condensation temperature at the first timing T1. Thestorage unit 32 stores the first air temperature Ta1 and the first condensation temperature Tc1 that are detected. In step S104, theacquisition unit 38 compares the first air temperature Ta1 and the first condensation temperature Tc1 with each other, thereby acquiring a first temperature difference ΔT1, which is a temperature difference at the first timing T1. The acquired first temperature difference ΔT1 is stored in thestorage unit 32. - Next, the second step ST2 and the third step ST3, which are illustrated in
Fig. 4 , will be described. The second step ST2 and the third step ST3 are performed after a certain period has elapsed from the first timing T1. Herein, the second step ST2 and the third step ST3 are performed at the time of maintenance after a period of about one year has elapsed from the first timing T1. This time of maintenance is a second timing T2. In step S105, theair conditioner 100 starts a test run as in step S101. In step S106, control is performed such that the frequency of thecompressor 23 becomes a predetermined value so as to set a state in which the frequency of thecompressor 23 is stabilized. In step S107, theair temperature sensor 36 of thedetection unit 31 detects a second air temperature Ta2, and thecondensation temperature sensor 37 detects a second condensation temperature Tc2. The second air temperature Ta2 is the air temperature at the second timing T2, and the second condensation temperature Tc2 is the condensation temperature at the second timing T2. Thestorage unit 32 stores the second air temperature Ta2 and the second condensation temperature Tc2 that are detected. In step S108, theacquisition unit 38 compares the second air temperature Ta2 and the second condensation temperature Tc2 with each other and acquires a second temperature difference ΔT2, which is a temperature difference at the second timing T2. The acquired second temperature difference ΔT2 is stored in thestorage unit 32. - Subsequently, in step S109, the
correction unit 33 corrects the first temperature difference ΔT1 and the second temperature difference ΔT2 by using a difference between the first air temperature Ta1 and the second air temperature Ta2 stored in thestorage unit 32. The method for correction performed by thecorrection unit 33 will be described later. In step S110, thedetermination unit 34 compares the corrected first temperature difference ΔT1 and the corrected second temperature difference ΔT2 with each other, and, if the temperature difference is 3°C or more, determines that the refrigerant leaks to the outside and that the amount of the refrigerant is insufficient. In step Sill, thenotification unit 35 notifies to an operator that the amount of the refrigerant is insufficient. -
Fig. 5 is a P-H chart obtained by experiment in which the amount of the refrigerant to be included in theair conditioner 100 is changed in a case in which the first air temperature Ta1 and the second air temperature Ta2 are at 35°C. It is found that the condensation temperature is lower in theair conditioner 100 in which the amount of the refrigerant is insufficient compared with theair conditioner 100 filled with a prescribed amount of the refrigerant. If the refrigerant included in theair conditioner 100 leaks by 20% from the prescribed amount, the first temperature difference ΔT1 and the second temperature difference ΔT2 diverges from each other by 3°C, and the performance efficiency of theair conditioner 100 decreases by 10%. From the experimental results, the present inventors have found that, if the first temperature difference ΔT1 and the second temperature difference ΔT2 are compared with each other, and if the temperature difference diverges by 2°C to 4°C or more, it can be determined that the refrigerant leaks to the outside and that the amount of the refrigerant is insufficient. - In addition, if the first air temperature Ta1 and the second air temperature Ta2 are at 25°C, and if the refrigerant included in the
air conditioner 100 leaks by 20% from the prescribed amount, the performance efficiency of theair conditioner 100 decreases by 9.4%. Furthermore, if the first air temperature Ta1 and the second air temperature Ta2 are at 45°C, and if the refrigerant included in theair conditioner 100 leaks by 20% from the prescribed amount, the performance efficiency of theair conditioner 100 decreases by 10.6%. - From these experimental results, for example, if the first air temperature Ta1 is 35°C, and if the second air temperature Ta2 is 25°C, the
correction unit 33 corrects the first temperature difference ΔTa1 by +0.4°C by using an air temperature of 25 °C as a reference temperature. If the difference between the first air temperature Ta1 and the second air temperature Ta2 corrected by thecorrection unit 33 diverges by 3°C or more, thedetermination unit 34 determines that the amount of the refrigerant is insufficient. - Herein, the
correction unit 33 may correct either one of the first temperature difference ΔT1 or the second temperature difference ΔT2 or may correct each of the first temperature difference ΔT1 and the second temperature difference ΔT2. In addition, in accordance with the difference between the first temperature difference ΔTa1 and the second temperature difference ΔTa2, the threshold used as a reference for determining the amount of the refrigerant may be corrected. Furthermore, a correction may also be made in accordance with a difference between the air temperature as a reference and each of the first air temperature Ta1 and the second air temperature Ta2. - The
air conditioner 100 as a refrigeration cycle apparatus according to the first embodiment includes theindoor unit 10, theoutdoor unit 20, therefrigerant connection pipe 15 that connects theindoor unit 10 and theoutdoor unit 20, and the refrigerantamount determination unit 30 that determines the amount of the refrigerant that flows in therefrigerant circuit 16. Therefrigerant circuit 16 of theair conditioner 100 is constituted by theindoor unit 10 and theoutdoor unit 20 being connected via therefrigerant connection pipe 15. The refrigerantamount determination unit 30 includes thedetection unit 31, thestorage unit 32, thecorrection unit 33, thedetermination unit 34, and thenotification unit 35. Thedetection unit 31 includes theair temperature sensor 36, thecondensation temperature sensor 37, and theacquisition unit 38. Theair temperature sensor 36 detects the air temperature that is the temperature of air that flows into theoutdoor heat exchanger 22 as a condenser. Thecondensation temperature sensor 37 detects the condensation temperature of the refrigerant that flows in theoutdoor heat exchanger 22. Theacquisition unit 38 acquires a temperature difference between the air temperature and the condensation temperature. Thedetermination unit 34 compares the first temperature difference ΔT1 and the second temperature difference ΔT2 with each other, thereby determining the amount of the refrigerant included in therefrigerant circuit 16. The first temperature difference ΔT1 is a temperature difference acquired by theacquisition unit 38 at the first timing T1 when theair conditioner 100 is installed. The second temperature difference ΔT2 is a temperature difference acquired by theacquisition unit 38 at the second timing T2 after a certain period has elapsed from the first timing T1. - In the
air conditioner 100 in which the amount of the refrigerant is insufficient, compared with theair conditioner 100 filled with a prescribed amount of the refrigerant, the condensation temperature decreases. Thus, by comparing the first temperature difference ΔT1 and the second temperature difference ΔT2 with each other, the amount of the refrigerant included in therefrigerant circuit 16 can be determined, and it can be determined whether the refrigerant leaks from therefrigerant circuit 16 to the outside by accidental means. - In addition, by comparing the second temperature difference ΔT2 with the first temperature difference ΔT1, it is possible to grasp the amount of the refrigerant in comparison with an initial amount of the refrigerant filled with a prescribed amount of the refrigerant and to protect the
air conditioner 100. - From the experimental knowledge in
Fig. 5 , the present inventors have found that the threshold used by thedetermination unit 34 to determine that the amount of the refrigerant is insufficient is 2°C to 4°C. If the difference between the first temperature difference ΔT1 and the second temperature difference ΔT2 is from 2°C to 4°C or more, by determining that the amount of the refrigerant is insufficient, thedetermination unit 34 can determine whether the refrigerant leaks from therefrigerant circuit 16 to the outside by accidental means. - If the
determination unit 34 determines that the amount of the refrigerant is insufficient, thenotification unit 35 notifies the insufficiency of the amount of the refrigerant. Thus, an operator who determines the amount of the refrigerant can notice the insufficiency of the amount of the refrigerant. - The
correction unit 33 corrects the temperature differences by using the air temperature stored in thestorage unit 32. By the correction made by thecorrection unit 33, the amount of the refrigerant is not necessarily determined under the same conditions as those at the first timing T1. This enables the operator to determine the amount of the refrigerant at any time. - In the
air conditioner 100 that is a refrigeration cycle apparatus according to the first embodiment, the first timing T1 may be the time of initial operation of theair conditioner 100 or the time of maintenance of theair conditioner 100. The second timing T2 is a maintenance timing at or after the maintenance performed at the first timing T1. - In the
air conditioner 100 according to the first embodiment, thecorrection unit 33 may make a correction by using the evaporation temperature of the refrigerant. In this case, theair conditioner 100 includes an evaporation temperature sensor that detects the evaporation temperature of the refrigerant. - If the evaporation temperature decreases by 5°C, the performance efficiency decreases by 9.4%. If the evaporation temperature increases by 5°C, the performance efficiency decreases by 10.6%. Thus, for example, when the evaporation temperature decreases by 5°C, the difference between the first temperature difference ΔT1 and the second temperature difference ΔT2 is corrected by +0.2°C. In contrast, when the evaporation temperature increases by 5°C, the temperature between the first temperature difference ΔT1 and the second temperature difference ΔT2 is corrected by -0.2°C.
- When the outdoor air temperature is 25°C with respect to the reference value that is an outdoor air temperature of 35°C and the evaporation temperature decreases by 5°C, the difference between the first temperature difference ΔT1 and the second temperature difference ΔT2 is corrected by +0.4°C. When the outdoor air temperature is 45°C and the evaporation temperature increases by 5°C, the difference between the first temperature difference ΔT1 and the second temperature difference ΔT2 is corrected by -0.4°C.
- In the
air conditioner 100 according to the first embodiment, in the determination of the amount of the refrigerant, thecorrection unit 33 does not necessarily make a correction. Theair conditioner 100 can determine the amount of the refrigerant without correction. - In the
air conditioner 100 according to the first embodiment, thestorage unit 32 does not necessarily store the first temperature difference ΔT1 and the second temperature difference ΔT2. Theair conditioner 100 may acquire the first temperature difference ΔT1 as necessary from the first air temperature Ta1 and the first condensation temperature Tc1 stored in thestorage unit 32, and thedetermination unit 34 may compare the acquired first temperature difference ΔT1 and the second temperature difference ΔT2 with each other. - In the
air conditioner 100 according to the first embodiment, the air temperature detected by theair temperature sensor 36 may be the temperature of outdoor air around installation site of theoutdoor unit 20. Theair temperature sensor 36 may be a sensor that detects the air temperature around theoutdoor unit 20. - As illustrated in
Fig. 6 , in theair conditioner 100 according to the first embodiment, thestorage unit 32, thecorrection unit 33, thedetermination unit 34, and theacquisition unit 38 may alternatively be included in aserver 150 connected to theair conditioner 100 via theInternet 39. - At this time, the detected air temperature and condensation temperature are transmitted to the
server 150. Thestorage unit 32, thecorrection unit 33, thedetermination unit 34, and theacquisition unit 38 in theserver 150 performs substantially the same operations as those in the refrigerant amount determination method according to the first embodiment. - Hereinafter, an embodiment of a refrigerant
amount determination system 200 according to a second embodiment will be described. - The refrigerant
amount determination system 200 according to this embodiment is a system that determines the amount of a refrigerant included in a refrigeration cycle apparatus. In this embodiment, as the refrigeration cycle apparatus, anair conditioner 300 is used. -
Fig. 7 schematically illustrates theair conditioner 300 according to this embodiment. Theair conditioner 300 performs indoor cooling and heating for buildings or the like by performing a vapor compression refrigeration cycle. Theair conditioner 300 mainly includes anindoor unit 310, anoutdoor unit 320, and a refrigerant connection pipe that connects theindoor unit 310 and theoutdoor unit 320. A refrigerant circuit of theair conditioner 300 is constituted by theindoor unit 310 and theoutdoor unit 320 being connected via the refrigerant connection pipe. - The
indoor unit 310 of theair conditioner 300 is installed, for example, by being hooked to a wall surface in a room or by being embedded in or hung from the ceiling in a room. Theindoor unit 310 is connected to theoutdoor unit 320 via the refrigerant connection pipe and constitutes part of the refrigerant circuit. Theindoor unit 310 includes anindoor fan 311 and anindoor heat exchanger 312. - The
outdoor unit 320 is installed outside. Theoutdoor unit 320 is connected to theindoor unit 310 via the refrigerant connection pipe and constitutes part of the refrigerant circuit. Theoutdoor unit 320 includes anoutdoor fan 321, anoutdoor heat exchanger 322, acompressor 323, a four-way switching valve 324, and anoutdoor expansion valve 325 as an expansion mechanism. - The refrigerant connection pipe is a refrigerant pipe that is constructed on site when the
air conditioner 300 is installed at an installation site. The refrigerant connection pipe is connected to theindoor unit 310 and theoutdoor unit 320 and constitutes the refrigerant circuit. Operations of theair conditioner 300 are substantially the same as those of theair conditioner 100 according to the first embodiment and thus will be omitted. - The refrigerant
amount determination system 200 is a retrofitted unit that is placed separately from theair conditioner 300. The refrigerantamount determination system 200 includes adetection unit 231, astorage unit 232, acorrection unit 233, adetermination unit 234, and anotification unit 235. - The
detection unit 231 includes anair temperature sensor 236, acondensation temperature sensor 237, and anacquisition unit 238. Theair temperature sensor 236 detects an air temperature that is the temperature of outdoor air that flows into theoutdoor heat exchanger 322. Thecondensation temperature sensor 237 detects the condensation temperature of the refrigerant. For example, thecondensation temperature sensor 237 is provided so as to be in contact with a heat exchanger tube (not illustrated) included in theoutdoor heat exchanger 322 of theair conditioner 300. Theacquisition unit 238 acquires a temperature difference between the air temperature detected by theair temperature sensor 236 and the condensation temperature detected by thecondensation temperature sensor 237. - The
storage unit 232 stores the air temperature detected by theair temperature sensor 236 and the temperature difference acquired by theacquisition unit 238. - The
correction unit 233 corrects the temperature difference by using the air temperature stored in thestorage unit 232. - The
determination unit 234 compares a plurality of temperature differences acquired by theacquisition unit 238 and determines a change in the amount of the refrigerant included in the refrigerant circuit. - If the
determination unit 234 determines that the amount of the refrigerant is insufficient, thenotification unit 235 notifies insufficiency of the amount of the refrigerant. Thenotification unit 235 notifies insufficiency of the amount of the refrigerant by using, for example, an LED or the like. - Next, a method for determining the amount of the refrigerant will be described with reference to
Fig. 8 and Fig. 9 . - The amount of the refrigerant is determined in a first step ST1, a second step ST2, and a third step ST3 in this order. In the first step ST1, step S201 to step S204 are performed. In the second step ST2, step S205 to step S209 are performed. In the third step ST3, step S210 and step S211 are performed. Each step will be described below. Note that substantially the same operations as those of the
air conditioner 100 according to the first embodiment will be omitted from the description. -
Fig. 8 is a flowchart illustrating operations of theair conditioner 300 and the refrigerantamount determination system 200 in the first step ST1. Theair conditioner 300 is installed on site in a state in which a prescribed amount of the refrigerant is included. The time at which theair conditioner 300 is installed is a first timing T1. Operations in step S201 to step S204 are substantially the same as operations in step S101 to step S104 in the first embodiment. - Next, the second step ST2 and the third step ST3, which are illustrated in
Fig. 9 , will be described. The second step ST2 is performed at the time of maintenance after a certain period has elapsed from the first timing T1. Step S205 is performed at the time of maintenance after a certain period has elapsed from the first timing T1. This time of maintenance is a second timing T2. Step S205 to step S211 are substantially the same as operations in step S205 to step S211 in the first embodiment below. - The basis for determining the insufficiency of the amount of the refrigerant is substantially the same as that in the first embodiment and thus will be omitted.
- The refrigerant
amount determination system 200 according to the second embodiment includes thedetection unit 231, thestorage unit 232, thecorrection unit 233, thedetermination unit 234, and thenotification unit 235. Thedetection unit 231 includes theair temperature sensor 236, thecondensation temperature sensor 237, and theacquisition unit 238. Theair temperature sensor 236 detects the air temperature that is the temperature of air that flows into theoutdoor heat exchanger 322 as a condenser. Thecondensation temperature sensor 237 detects the condensation temperature of the refrigerant that flows in theoutdoor heat exchanger 322. Theacquisition unit 238 acquires a temperature difference between the air temperature and the condensation temperature. Thedetermination unit 234 compares a first temperature difference ΔT1 and a second temperature difference ΔT2 with each other, thereby determining the amount of the refrigerant included in the refrigerant circuit. The first temperature difference ΔT1 is a temperature difference acquired by theacquisition unit 238 at the first timing T1 when theair conditioner 300 is installed. The second temperature difference ΔT2 is a temperature difference acquired by theacquisition unit 238 at the second timing T2 after a certain period has elapsed from the first timing T1. - In the
air conditioner 300 in which the amount of the refrigerant is insufficient, compared with theair conditioner 300 filled with a prescribed amount of refrigerant, the condensation temperature decreases. Thus, by comparing the first temperature difference ΔT1 and the second temperature difference ΔT2 with each other, the amount of the refrigerant included in the refrigerant circuit can be determined, and it can be determined whether the refrigerant leaks from the refrigerant circuit to the outside by accidental means. - In addition, by comparing the second temperature difference ΔT2 with the first temperature difference ΔT1, it is possible to grasp the amount of the refrigerant in comparison with an initial amount of the refrigerant filled with a prescribed amount of the refrigerant and to protect the
air conditioner 300. - From the experimental knowledge in
Fig. 5 , the present inventors have found that the threshold used by thedetermination unit 234 to determine that the amount of the refrigerant is insufficient is 2°C to 4°C. If the difference between the first temperature difference ΔT1 and the second temperature difference ΔT2 is from 2°C to 4°C or more, by determining that the amount of the refrigerant is insufficient, thedetermination unit 234 can determine whether the refrigerant leaks from the refrigerant circuit to the outside by accidental means. - If the
determination unit 234 determines that the amount of the refrigerant is insufficient, thenotification unit 235 notifies the insufficiency of the amount of the refrigerant. Thus, an operator who determines the amount of the refrigerant can notice the insufficiency of the amount of the refrigerant. - The
correction unit 233 corrects the temperature differences by using the air temperature stored in thestorage unit 232. By the correction made by thecorrection unit 233, the amount of the refrigerant is not necessarily determined under the same conditions as those at the first timing T1. This enables the operator to determine the amount of the refrigerant at any time. - The modifications in the first embodiment are applicable to the second embodiment.
- Although the embodiments of the present disclosure have been described above, it should be understood that various changes can be made on the forms and details without departing from the spirit and scope of the present disclosure described in the scope of claims.
-
- 12
- evaporator
- 16
- refrigerant circuit
- 22
- condenser
- 23
- compressor
- 25
- expansion mechanism
- 32
- storage unit
- 33
- correction unit
- 34
- determination unit
- 35
- notification unit
- 36
- air temperature sensor
- 37
- condensation temperature sensor
- 38
- acquisition unit
- 100
- refrigeration cycle apparatus
- 200
- refrigerant amount determination system
- 232
- storage unit
- 233
- correction unit
- 234
- determination unit
- 235
- notification unit
- 236
- air temperature sensor
- 237
- condensation temperature sensor
- 238
- acquisition unit
- 300
- refrigeration cycle apparatus
- 312
- evaporator
- 322
- condenser
- 323
- compressor
- 325
- expansion mechanism
- T1
- first timing
- T2
- second timing
- ΔT1
- first temperature difference
- ΔT2
- second temperature difference
- Ta1, Ta2
- air temperature
- Tc1, Tc2
- condensation temperature
- PTL 1:
Japanese Unexamined Patent Application Publication No. H6-159869
Claims (13)
- A refrigeration cycle apparatus (100) in which a refrigerant circulates in a refrigerant circuit (16) constituted by a compressor (23), a condenser (22), an expansion mechanism (25), and an evaporator (12) being connected, the refrigeration cycle apparatus comprising:an air temperature sensor (36) that detects an air temperature (Tal, Ta2), which is a temperature of air that flows into the condenser (22);a condensation temperature sensor (37) that detects a condensation temperature (Tc1, Tc2) of the refrigerant that flows through the condenser (22);an acquisition unit (38) that acquires a temperature difference between the air temperature (Tal, Ta2) and the condensation temperature (Tc1, Tc2); anda determination unit (34) that determines an amount of the refrigerant included in the refrigerant circuit (16) by comparing a first temperature difference (ΔT1) and a second temperature difference (ΔT2) with each other, the first temperature difference (ΔT1) being a temperature difference acquired by the acquisition unit (38) at a first timing (T1), the second temperature difference (ΔT2) being a temperature difference acquired by the acquisition unit (38) at a second timing (T2).
- The refrigeration cycle apparatus according to Claim 1, further comprising:
a storage unit (32) that stores at least one of the first temperature difference (ΔT1) or the air temperature (Tal, Ta2) and the condensation temperature (Tc1, Tc2) acquired at the first timing (T1). - The refrigeration cycle apparatus according to Claim 1 or 2,
wherein the first timing (T1) is any of a time at which the refrigeration cycle apparatus (100) is installed, at a time of initial operation of the refrigeration cycle apparatus (100), or a time of maintenance of the refrigeration cycle apparatus (100). - The refrigeration cycle apparatus according to any of Claims 1 to 3,
wherein, if a difference between the first temperature difference (ΔT1) and the second temperature difference (ΔT2) is greater than or equal to a threshold that is any value from 2°C to 4°C, the determination unit (34) determines that the amount of the refrigerant included in the refrigerant circuit (16) is insufficient. - The refrigeration cycle apparatus according to any of Claims 1 to 4, further comprising:
a notification unit (35) that notifies insufficiency of the amount of the refrigerant if the determination unit (34) determines that the amount of the refrigerant is insufficient. - The refrigeration cycle apparatus according to any of Claims 1 to 5, further comprising:
a correction unit (33) that corrects the first temperature difference (ΔT1) and the second temperature difference (ΔT2) by using at least either one of the air temperature (Tal, Ta2) or an evaporation temperature of the refrigerant. - A refrigerant amount determination system (200) that determines an amount of a refrigerant included in a refrigeration cycle apparatus (300) in which the refrigerant circulates in a refrigerant circuit constituted by a compressor (323), a condenser (322), an expansion mechanism (325), and an evaporator (312) being connected, the refrigerant amount determination system comprising:an air temperature sensor (236) that detects an air temperature (Tal, Ta2), which is a temperature of air that flows into the condenser (322);a condensation temperature sensor (237) that detects a condensation temperature (Tc1, Tc2) of the refrigerant that flows through the condenser (322);an acquisition unit (238) that acquires a temperature difference between the air temperature (Tal, Ta2) and the condensation temperature (Tc1, Tc2); anda determination unit (234) that determines a change in the amount of the refrigerant included in the refrigerant circuit by comparing a first temperature difference (ΔT1) and a second temperature difference (ΔT2) with each other, the first temperature difference (ΔT1) being a temperature difference acquired by the acquisition unit (238) at a first timing (T1), the second temperature difference (ΔT2) being a temperature difference acquired by the acquisition unit (238) at a second timing (T2).
- The refrigerant amount determination system according to Claim 7, further comprising:
a storage unit (232) that stores at least one of the first temperature difference (ΔT1) or the air temperature (Tal, Ta2) and the condensation temperature (Tc1, Tc2) acquired at the first timing (T1). - The refrigerant amount determination system according to Claim 7 or 8,
wherein the first timing (T1) is any of a time at which the refrigeration cycle apparatus (300) is installed, at a time of initial operation of the refrigeration cycle apparatus (300), or a time of maintenance of the refrigeration cycle apparatus (300). - The refrigerant amount determination system according to any of Claims 7 to 9,
wherein, if a difference between the first temperature difference (ΔT1) and the second temperature difference (ΔT2) is greater than or equal to a threshold that is any value from 2°C to 4°C, the determination unit (234) determines that the amount of the refrigerant included in the refrigerant circuit is insufficient. - The refrigerant amount determination system according to any of Claims 7 to 10, further comprising:
a notification unit (235) that notifies insufficiency of the amount of the refrigerant if the determination unit (234) determines that the amount of the refrigerant is insufficient. - The refrigerant amount determination system according to any of Claims 7 to 11, further comprising:
a correction unit (233) that corrects the first temperature difference (ΔT1) and the second temperature difference (ΔT2) by using at least either one of the air temperature (Tal, Ta2) or an evaporation temperature of the refrigerant. - A refrigerant amount determination method for determining an amount of a refrigerant included in a refrigeration cycle apparatus (100, 300) in which the refrigerant circulates in a refrigerant circuit (16) constituted by a compressor (23, 323), a condenser (22, 322), an expansion mechanism (25, 325), and an evaporator (12, 312) being connected, the refrigerant amount determination method comprising:a first step (ST1) of acquiring a first temperature difference (ΔT1), which is a temperature difference detected at a first timing (T1), between an air temperature (Tal, Ta2) and a condensation temperature (Tc1, Tc2), the air temperature (Ta1, Ta2) being a temperature of air that flows into the condenser (22, 322), the condensation temperature (Tc1, Tc2) being a condensation temperature of the refrigerant that flows through the condenser (22, 322);a second step (ST2) of acquiring a second temperature difference (ΔT2), which is a temperature difference detected at a second timing (T2), between the air temperature (Tal, Ta2) and the condensation temperature (Tc1, Tc2), the air temperature (Tal, Ta2) being a temperature of air that flows into the condenser (22, 322), the condensation temperature (Tc1, Tc2) being a condensation temperature of the refrigerant that flows through the condenser (22, 322); anda third step (ST3) of determining a change in the amount of the refrigerant included in the refrigerant circuit (16) by comparing the first temperature difference (ΔT1) and the second temperature difference (ΔT2) with each other.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2018216841A JP2020085280A (en) | 2018-11-19 | 2018-11-19 | Refrigerant cycle device, refrigerant amount determination system and refrigerant amount determination method |
PCT/JP2019/044420 WO2020105515A1 (en) | 2018-11-19 | 2019-11-12 | Refrigerant cycle device, refrigerant amount determination system, and refrigerant amount determination method |
Publications (2)
Publication Number | Publication Date |
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EP3885676A1 true EP3885676A1 (en) | 2021-09-29 |
EP3885676A4 EP3885676A4 (en) | 2022-08-10 |
Family
ID=70773414
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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EP19887164.2A Withdrawn EP3885676A4 (en) | 2018-11-19 | 2019-11-12 | Refrigerant cycle device, refrigerant amount determination system, and refrigerant amount determination method |
Country Status (5)
Country | Link |
---|---|
US (1) | US20220003472A1 (en) |
EP (1) | EP3885676A4 (en) |
JP (1) | JP2020085280A (en) |
CN (1) | CN112888907A (en) |
WO (1) | WO2020105515A1 (en) |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
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US11231198B2 (en) | 2019-09-05 | 2022-01-25 | Trane International Inc. | Systems and methods for refrigerant leak detection in a climate control system |
WO2024095444A1 (en) * | 2022-11-04 | 2024-05-10 | 三菱電機株式会社 | Air conditioning system |
Family Cites Families (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH06159869A (en) * | 1992-11-18 | 1994-06-07 | Mitsubishi Heavy Ind Ltd | Air conditioner |
JPH06185838A (en) * | 1992-12-16 | 1994-07-08 | Zexel Corp | Refrigerant shortage detector for refrigerant circulation cycle |
US7610765B2 (en) * | 2004-12-27 | 2009-11-03 | Carrier Corporation | Refrigerant charge status indication method and device |
JP4165566B2 (en) * | 2006-01-25 | 2008-10-15 | ダイキン工業株式会社 | Air conditioner |
US8590325B2 (en) * | 2006-07-19 | 2013-11-26 | Emerson Climate Technologies, Inc. | Protection and diagnostic module for a refrigeration system |
JP5063346B2 (en) * | 2006-09-21 | 2012-10-31 | 三菱電機株式会社 | Refrigeration and air conditioning system having refrigerant leakage detection function, refrigeration and air conditioning apparatus, and refrigerant leakage detection method |
WO2014165731A1 (en) * | 2013-04-05 | 2014-10-09 | Emerson Electric Co. | Heat-pump system with refrigerant charge diagnostics |
JP2016161256A (en) * | 2015-03-04 | 2016-09-05 | 株式会社富士通ゼネラル | Air conditioner |
JP6582496B2 (en) * | 2015-03-31 | 2019-10-02 | ダイキン工業株式会社 | Air conditioning indoor unit |
-
2018
- 2018-11-19 JP JP2018216841A patent/JP2020085280A/en active Pending
-
2019
- 2019-11-12 WO PCT/JP2019/044420 patent/WO2020105515A1/en unknown
- 2019-11-12 CN CN201980069845.7A patent/CN112888907A/en active Pending
- 2019-11-12 US US17/294,890 patent/US20220003472A1/en not_active Abandoned
- 2019-11-12 EP EP19887164.2A patent/EP3885676A4/en not_active Withdrawn
Also Published As
Publication number | Publication date |
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EP3885676A4 (en) | 2022-08-10 |
WO2020105515A1 (en) | 2020-05-28 |
CN112888907A (en) | 2021-06-01 |
US20220003472A1 (en) | 2022-01-06 |
JP2020085280A (en) | 2020-06-04 |
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