# US 12,000,604 B2 · Failure diagnosis system configured to diagnose a state of an air-conditioning apparatus having a refrigerant circuit > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,000,604 B2 - Document ID: US12000604B2 - Status: Granted - Kind: B2 - Application number: 17/040,657 - Filed: 2018-05-14 - Published: 2021-01-21 - Granted: 2024-06-04 - Earliest claimed: 2018-05-14 - Assignees: Mitsubishi Electric Corporation - Applicants: Mitsubishi Electric Corporation - Inventors: Takehiro Koyano - Web page: https://patentgrep.com/patent/US12000604B2 ## CPC - F24F 11/38: Failure diagnosis - F24F 11/62: characterised by the type of control or by internal processing, e.g. using fuzzy logic, adaptive control or estimation of values - F25B 13/00: Compression machines, plants or systems, with reversible cycle (defrosting cycles F25B47/02) - F25B 40/00: Subcoolers, desuperheaters or superheaters - F25B 41/39: Dispositions with two or more expansion means arranged in series, i.e. multi-stage expansion, on a refrigerant line leading to the same evaporator - F25B 49/005: {of safety devices (F25B49/02 and F25B49/04 take precedence)} - F25B 49/022: {Compressor control arrangements} - F25B 49/027: {Condenser control arrangements} - F24F 11/52: Indication arrangements, e.g. displays - F24F 2110/10: Temperature - F24F 2110/12: of the outside air - F24F 2140/20: Heat-exchange fluid temperature - F25B 2313/0292: related to reversing valves - F25B 2313/0293: related to the indoor fan, e.g. controlling speed - F25B 2313/0294: related to the outdoor fan, e.g. controlling speed - F25B 2313/0314: Temperature sensors near the indoor heat exchanger - F25B 2313/0315: Temperature sensors near the outdoor heat exchanger - F25B 2700/21152: at the discharge side of the compressor - 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) - F25B: REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS ## Abstract A failure diagnosis system diagnoses the state of an air-conditioning apparatus having a refrigerant circuit in which refrigerant circulates. The failure diagnosis system has an abnormality diagnosis unit that performs normal-operation abnormality diagnosis for determining whether or not there is an abnormality in the air-conditioning apparatus by using state data and control data during normal operation of the air-conditioning apparatus. If the abnormality diagnosis unit determines that there is an abnormality, it changes a control value for an actuator of the air-conditioning apparatus and acquires state data and control data. Then, the abnormality diagnosis unit performs abnormality-cause identification diagnosis for identifying the cause of the abnormality in the air-conditioning apparatus by using the state data and the control data acquired before the change of the control value and the state data and the control data acquired after the change of the control value. ## Claims ### Claim 1 A failure diagnosis system configured to diagnose a state of an air-conditioning apparatus having a refrigerant circuit in which refrigerant circulates, the failure diagnosis system comprising: a state detection sensor configured to detect a state of the refrigerant in the refrigerant circuit as state data; a controller configured to control an actuator of the air-conditioning apparatus; a processor, and the processor being configured to perform normal-operation abnormality diagnosis determining presence or absence of abnormality of the air-conditioning apparatus by using the state data, and control data indicating a content of control by the controller during a normal operation of the air-conditioning apparatus, the processor being configured to, when determining that abnormality is present in the air-conditioning apparatus, change a control value of the actuator of the air-conditioning apparatus, acquire the state data and the control data, and perform abnormality-cause identification diagnosis identifying a cause of an abnormality of the air-conditioning apparatus by using the state data and the control data that are acquired before the change of the control value of the actuator, and the state data and the control data that are acquired after the change of the control value of the actuator, wherein the processor is configured to obtain refrigerant state information, indicating the state of the refrigerant at a specific location of the refrigerant circuit, by using the state data and the control data in the normal-operation abnormality diagnosis, and obtain the refrigerant state information by using the state data and the control data after the change of the control value of the actuator and compare the obtained refrigerant state information with the refrigerant state information obtained in the normal-operation abnormality diagnosis to identify the cause of the abnormality in the air-conditioning apparatus in the abnormality-cause identification diagnosis, wherein the processor is configured to cause a management apparatus to display the refrigerant state information obtained in the normal-operation abnormality diagnosis and the refrigerant state information acquired after the change of the control value of the actuator, the management apparatus being configured to manage the air-conditioning apparatus. ### Claim 2 A failure diagnosis system configured to diagnose a state of an air-conditioning apparatus having a refrigerant circuit in which refrigerant circulates, the failure diagnosis system comprising: a state detection sensor configured to detect a state of the refrigerant in the refrigerant circuit as state data; a controller configured to control an actuator of the air-conditioning apparatus; a processor, and the processor being configured to perform normal-operation abnormality diagnosis determining presence or absence of abnormality of the air-conditioning apparatus by using the state data, and control data indicating a content of control by the controller during a normal operation of the air-conditioning apparatus, the processor being configured to, when determining that abnormality is present in the air-conditioning apparatus, change a control value of the actuator of the air-conditioning apparatus, acquire the state data and the control data, and perform abnormality-cause identification diagnosis identifying a cause of an abnormality of the air-conditioning apparatus by using the state data and the control data that are acquired before the change of the control value of the actuator, and the state data and the control data that are acquired after the change of the control value of the actuator, wherein the processor is configured to obtain refrigerant state information, indicating the state of the refrigerant at a specific location of the refrigerant circuit, by using the state data and the control data in the normal-operation abnormality diagnosis, and obtain the refrigerant state information by using the state data and the control data after the change of the control value of the actuator and compare the obtained refrigerant state information with the refrigerant state information obtained in the normal-operation abnormality diagnosis to identify the cause of the abnormality in the air-conditioning apparatus in the abnormality-cause identification diagnosis, further comprising a communication device serving as an interface when the processor communicates with an external device, wherein the processor is configured to cause an information terminal connected via the communication device to display the refrigerant state information obtained in the normal-operation abnormality diagnosis and the refrigerant state information acquired after the change of the control value of the actuator.