US20220003472A1 - Refrigeration cycle apparatus, refrigerant amount determination system, and refrigerant amount determination method - Google Patents

Refrigeration cycle apparatus, refrigerant amount determination system, and refrigerant amount determination method Download PDF

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Publication number
US20220003472A1
US20220003472A1 US17/294,890 US201917294890A US2022003472A1 US 20220003472 A1 US20220003472 A1 US 20220003472A1 US 201917294890 A US201917294890 A US 201917294890A US 2022003472 A1 US2022003472 A1 US 2022003472A1
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Prior art keywords
refrigerant
temperature
temperature difference
amount
refrigeration cycle
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US17/294,890
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English (en)
Inventor
Noriyuki Okuda
Tooru Nishikawa
Masahiro Honda
Hiroshi Yoh
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Daikin Industries Ltd
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Daikin Industries Ltd
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Assigned to DAIKIN INDUSTRIES, LTD. reassignment DAIKIN INDUSTRIES, LTD. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: NISHIKAWA, TOORU, OKUDA, NORIYUKI, HONDA, MASAHIRO, YOH, HIROSHI
Publication of US20220003472A1 publication Critical patent/US20220003472A1/en
Abandoned legal-status Critical Current

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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
    • 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
    • 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
    • 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
    • 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
    • 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
    • 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 an air conditioner according to a first embodiment.
  • FIG. 2 is a block diagram of a refrigeration cycle apparatus according to the first embodiment.
  • FIG. 3 is a flowchart illustrating operations of the refrigeration cycle apparatus in a first step.
  • FIG. 4 is a flowchart illustrating operations of the refrigeration cycle apparatus in a second step and a third step.
  • FIG. 5 is a P-H chart regarding a relationship between the amount of a refrigerant and an air temperature.
  • FIG. 6 is a block diagram of Modification 6 according to the first embodiment.
  • FIG. 7 is a block diagram of a refrigeration cycle apparatus according to a second embodiment.
  • FIG. 8 is a flowchart illustrating operations of the refrigeration cycle apparatus and a refrigerant amount determination system in a first step.
  • 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.
  • 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 .
  • As the refrigerant that circulates in the refrigerant circuit 16 R410A, R32, R407C, R22, R134a, carbon dioxide, or the like is used.
  • 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 ST 1 , a second step ST 2 , and a third step ST 3 in this order.
  • step S 101 to step S 104 are performed.
  • step S 105 to step S 109 are performed.
  • step S 110 and step S 111 are performed.
  • Each step will be described below.
  • FIG. 3 is a flowchart illustrating operations of the air conditioner 100 in the first step ST 1 .
  • 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 T 1 .
  • the air conditioner 100 starts a test run for detecting the air temperature and the condensation temperature.
  • 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 Ta 1
  • the condensation temperature sensor 37 detects a first condensation temperature Tc 1 .
  • the first air temperature Ta 1 is the air temperature at the first timing T 1
  • the first condensation temperature Tc 1 is the condensation temperature at the first timing T 1
  • the storage unit 32 stores the first air temperature Ta 1 and the first condensation temperature Tc 1 that are detected.
  • the acquisition unit 38 compares the first air temperature Ta 1 and the first condensation temperature Tc 1 with each other, thereby acquiring a first temperature difference ⁇ T 1 , which is a temperature difference at the first timing T 1 .
  • the acquired first temperature difference ⁇ T 1 is stored in the storage unit 32 .
  • step S 105 the air conditioner 100 starts a test run as in step S 101 .
  • step S 106 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 S 107 the air temperature sensor 36 of the detection unit 31 detects a second air temperature Ta 2 , and the condensation temperature sensor 37 detects a second condensation temperature Tc 2 .
  • the second air temperature Ta 2 is the air temperature at the second timing T 2
  • the second condensation temperature Tc 2 is the condensation temperature at the second timing T 2 .
  • the storage unit 32 stores the second air temperature Ta 2 and the second condensation temperature Tc 2 that are detected.
  • the acquisition unit 38 compares the second air temperature Ta 2 and the second condensation temperature Tc 2 with each other and acquires a second temperature difference ⁇ T 2 , which is a temperature difference at the second timing T 2 .
  • the acquired second temperature difference ⁇ T 2 is stored in the storage unit 32 .
  • step S 109 the correction unit 33 corrects the first temperature difference ⁇ T 1 and the second temperature difference ⁇ T 2 by using a difference between the first air temperature Ta 1 and the second air temperature Ta 2 stored in the storage unit 32 .
  • the method for correction performed by the correction unit 33 will be described later.
  • the determination unit 34 compares the corrected first temperature difference ⁇ T 1 and the corrected second temperature difference ⁇ T 2 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 S 111 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 Ta 1 and the second air temperature Ta 2 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 ⁇ T 1 and the second temperature difference ⁇ T 2 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 ⁇ T 1 and the second temperature difference ⁇ T 2 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 Ta 1 and the second air temperature Ta 2 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 ⁇ Ta 1 by +0.4° C. by using an air temperature of 25 ° C. as a reference temperature. If the difference between the first air temperature Ta 1 and the second air temperature Ta 2 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 ⁇ T 1 or the second temperature difference ⁇ T 2 or may correct each of the first temperature difference ⁇ T 1 and the second temperature difference ⁇ T 2 .
  • 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 Ta 1 and the second air temperature Ta 2 .
  • 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 ⁇ T 1 and the second temperature difference ⁇ T 2 with each other, thereby determining the amount of the refrigerant included in the refrigerant circuit 16 .
  • the first temperature difference ⁇ T 1 is a temperature difference acquired by the acquisition unit 38 at the first timing T 1 when the air conditioner 100 is installed.
  • the second temperature difference ⁇ T 2 is a temperature difference acquired by the acquisition unit 38 at the second timing T 2 after a certain period has elapsed from the first timing T 1 .
  • 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 present inventors have found that 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 ⁇ T 1 and the second temperature difference ⁇ T 2 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 .
  • the amount of the refrigerant is not necessarily determined under the same conditions as those at the first timing T 1 . This enables the operator to determine the amount of the refrigerant at any time.
  • the first timing T 1 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 T 2 is a maintenance timing at or after the maintenance performed at the first timing T 1 .
  • 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 ⁇ T 1 and the second temperature difference ⁇ T 2 is corrected by +0.2° C.
  • the temperature between the first temperature difference ⁇ T 1 and the second temperature difference ⁇ T 2 is corrected by ⁇ 0.2° C.
  • the difference between the first temperature difference ⁇ T 1 and the second temperature difference ⁇ T 2 is corrected by +0.4° C.
  • the difference between the first temperature difference ⁇ T 1 and the second temperature difference ⁇ T 2 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 ⁇ T 1 and the second temperature difference ⁇ T 2 .
  • the air conditioner 100 may acquire the first temperature difference ⁇ T 1 as necessary from the first air temperature Ta 1 and the first condensation temperature Tc 1 stored in the storage unit 32 , and the determination unit 34 may compare the acquired first temperature difference ⁇ T 1 and the second temperature difference ⁇ T 2 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 ST 1 , a second step ST 2 , and a third step ST 3 in this order.
  • step S 201 to step S 204 are performed.
  • step S 205 to step S 209 are performed.
  • step S 210 and step S 211 are performed.
  • step S 210 and step S 211 are performed.
  • FIG. 8 is a flowchart illustrating operations of the air conditioner 300 and the refrigerant amount determination system 200 in the first step ST 1 .
  • 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 T 1 .
  • Operations in step S 201 to step S 204 are substantially the same as operations in step S 101 to step S 104 in the first embodiment.
  • the second step ST 2 is performed at the time of maintenance after a certain period has elapsed from the first timing T 1 .
  • Step S 205 is performed at the time of maintenance after a certain period has elapsed from the first timing T 1 .
  • This time of maintenance is a second timing T 2 .
  • Step S 205 to step S 211 are substantially the same as operations in step S 205 to step S 211 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 ⁇ T 1 and a second temperature difference ⁇ T 2 with each other, thereby determining the amount of the refrigerant included in the refrigerant circuit.
  • the first temperature difference ⁇ T 1 is a temperature difference acquired by the acquisition unit 238 at the first timing T 1 when the air conditioner 300 is installed.
  • the second temperature difference ⁇ T 2 is a temperature difference acquired by the acquisition unit 238 at the second timing T 2 after a certain period has elapsed from the first timing T 1 .
  • 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 present inventors have found that 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 ⁇ T 1 and the second temperature difference ⁇ T 2 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 T 1 . This enables the operator to determine the amount of the refrigerant at any time.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Thermal Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Air Conditioning Control Device (AREA)
US17/294,890 2018-11-19 2019-11-12 Refrigeration cycle apparatus, refrigerant amount determination system, and refrigerant amount determination method Abandoned US20220003472A1 (en)

Applications Claiming Priority (3)

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JP2018-216841 2018-11-19
JP2018216841A JP2020085280A (ja) 2018-11-19 2018-11-19 冷媒サイクル装置、冷媒量判断システム、及び、冷媒量判断方法
PCT/JP2019/044420 WO2020105515A1 (ja) 2018-11-19 2019-11-12 冷媒サイクル装置、冷媒量判断システム、及び、冷媒量判断方法

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EP3885676A1 (en) 2021-09-29
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JP2020085280A (ja) 2020-06-04
WO2020105515A1 (ja) 2020-05-28

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