# US 11,994,326 B2 · Refrigerant leakage detection system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,994,326 B2 - Document ID: US11994326B2 - Status: Granted - Kind: B2 - Application number: 18/387,922 - Filed: 2023-11-08 - Published: 2024-02-29 - Granted: 2024-05-28 - Earliest claimed: 2021-05-21 - Assignees: Daikin Industries, Ltd. - Applicants: Daikin Industries, Ltd. - Inventors: Junya Minami - Web page: https://patentgrep.com/patent/US11994326B2 ## CPC - F25B 49/005: {of safety devices (F25B49/02 and F25B49/04 take precedence)} - F25B 49/02: for compression type machines, plants or systems - F24F 11/36: to leakage of heat-exchange fluid - F24F 11/49: ensuring correct operation, e.g. by trial operation or configuration checks - F24F 11/89: Arrangement or mounting of control or safety devices - G01M 3/002: {by using thermal means} - F25B 13/00: Compression machines, plants or systems, with reversible cycle (defrosting cycles F25B47/02) - F25B 2313/0233: in parallel arrangements - F25B 2313/0314: Temperature sensors near the indoor heat exchanger - F25B 2313/0315: Temperature sensors near the outdoor heat exchanger - F25B 2500/19: Calculation of parameters - F25B 2500/222: Detecting refrigerant leaks - F25B 2700/02: Humidity - F25B 2700/04: Refrigerant level - F25B 2700/151: of the compressor motor - F25B 2700/171: of the compressor - F25B 2700/1931: Discharge pressures - F25B 2700/1933: Suction pressures - F25B 2700/2104: of an indoor room or compartment - F25B 2700/2106: of fresh outdoor air - F25B 2700/21151: at the suction side of the compressor - F25B 2700/21152: at the discharge side of the compressor - G01F 25/00: Testing or calibration of apparatus for measuring volume, volume flow or liquid level or for metering by volume - F25B: REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS - F24F: AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING (removing dirt or fumes from areas where they are produced B08B15/00; vertical ducts for carrying away waste gases from buildings E04F17/02; tops for chimneys or ventilating shafts, terminals for flues F23L17/02) - G01M: TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR - G01F: MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME ## Abstract A refrigerant leakage detection system includes a first controller, and a second controller. The first controller uses a first method to determine the presence or absence of refrigerant leakage from the refrigerant circuit. The second controller uses a second method different from the first method to determine the presence or absence of refrigerant leakage from the refrigerant circuit. The refrigerant leakage detection system determines the presence or absence of refrigerant leakage from the refrigerant circuit on the basis of the determination result of the first controller and the determination result of the second controller. The refrigerant leakage detection system determines that there is a refrigerant leakage in the refrigerant circuit if the first controller determines that there is a refrigerant leakage from the refrigerant circuit and the second controller determines that there is a refrigerant leakage from the refrigerant circuit. ## Claims ### Claim 1 A refrigerant leakage detection system for a refrigeration cycle device having a refrigerant circuit, the refrigerant leakage detection system comprising: a first controller that uses a first method to determine a presence or absence of refrigerant leakage from the refrigerant circuit; and a second controller that uses a second method different from the first method to determine the presence or absence of refrigerant leakage from the refrigerant circuit, wherein the refrigerant leakage detection system determines that there is a refrigerant leakage in the refrigerant circuit if the first controller determines that there is a refrigerant leakage from the refrigerant circuit and the second controller determines that there is a refrigerant leakage from the refrigerant circuit, the first controller determines the presence or absence of refrigerant leakage on the basis of an operational state of the refrigeration cycle device during a first period, and the second controller determines the presence or absence of refrigerant leakage on the basis of an operational state of the refrigeration cycle device during a second period that is longer than the first period. ### Claim 2 (depends on 1) The refrigerant leakage detection system according to claim 1, wherein the operational state of the refrigeration cycle device during the second period includes an operational state of the refrigeration cycle device during test operation. ### Claim 3 (depends on 2) The refrigerant leakage detection system according to claim 2, wherein the first controller is included in the refrigeration cycle device, and the second controller is included in a first device that centrally manages the refrigeration cycle device or a second device that remotely manages the refrigeration cycle device. ### Claim 4 (depends on 2) The refrigerant leakage detection system according to claim 2, further comprising memory, wherein the first controller periodically acquires first data indicating the operational state of the refrigeration cycle device during the first period, the first data is accumulated in the memory, and the second controller calculates a moving average of the first data during the second period on the basis of the first data accumulated in the memory. ### Claim 5 (depends on 1) The refrigerant leakage detection system according to claim 1, wherein the first period falls within a range of 1 to 60 minutes, and the second period is one or more days. ### Claim 6 (depends on 5) The refrigerant leakage detection system according to claim 5, wherein the first controller is included in the refrigeration cycle device, and the second controller is included in a first device that centrally manages the refrigeration cycle device or a second device that remotely manages the refrigeration cycle device. ### Claim 7 (depends on 5) The refrigerant leakage detection system according to claim 5, further comprising memory, wherein the first controller periodically acquires first data indicating the operational state of the refrigeration cycle device during the first period, the first data is accumulated in the memory, and the second controller calculates a moving average of the first data during the second period on the basis of the first data accumulated in the memory. ### Claim 8 (depends on 1) The refrigerant leakage detection system according to claim 1, wherein the first controller is included in the refrigeration cycle device, and the second controller is included in a first device that centrally manages the refrigeration cycle device or a second device that remotely manages the refrigeration cycle device. ### Claim 9 (depends on 8) The refrigerant leakage detection system according to claim 8, further comprising memory, wherein the first controller periodically acquires first data indicating the operational state of the refrigeration cycle device during the first period, the first data is accumulated in the memory, and the second controller calculates a moving average of the first data during the second period on the basis of the first data accumulated in the memory. ### Claim 10 (depends on 1) The refrigerant leakage detection system according to claim 1, further comprising memory, wherein the first controller periodically acquires first data indicating the operational state of the refrigeration cycle device during the first period, the first data is accumulated in the memory, and the second controller calculates a moving average of the first data during the second period on the basis of the first data accumulated in the memory.