Mitsubishi Electric Corporation

Takehiro Koyano

Kosuke Tanaka

Yoshiaki Koizumi

Keisuke Takayama

Yasutaka Ochiai

Katsuya Taniguchi

Naohiro Ichikawa

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.

Failure diagnosis system configured to diagnose a state of an air-conditioning apparatus having a refrigerant circuit

A state analysis device and a state analyzer system include a specific state determination unit that determines specific state information representing a state of refrigerant at a specific position in a refrigeration circuit and a normal region determination unit that determines a normal region in a state space within which the specific state information is present when an air-conditioning apparatus operates under a normal state. The state analysis device and the state analyzer system allow a display to display the specific state information and the normal region.

State analyzer system and state analysis device

An airtightness evaluation device includes a differential pressure gauge to output a pressure difference between two spaces connected to two joints. A system joint for connecting a refrigeration cycle system is connected to one joint of the differential pressure gauge. A pressure vessel is connected to the other joint of the differential pressure gauge. The airtightness evaluation device includes a bypass circuit to connect the system joint and the pressure vessel to each other with bypassing the differential pressure gauge, and a bypass valve to open/close the bypass circuit. The airtightness evaluation device also includes a supply source joint for supplying a pressurization gas to the pressure vessel.

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Tokyo, Japan

Takehiro Koyano