DEVICE DIAGNOSIS DEVICE, FREEZING CYCLE DEVICE, FLUID CIRCUIT DIAGNOSIS METHOD, DEVICE MONITORING SYSTEM, AND FREEZING CYCLE MONITORING SYSTEM

摘要

A failure diagnosis apparatus for a refrigerating cycle had a problem that it has a low precision because the fluid is treated, and it is difficult to detect a foretaste of failure, absorb individual differences of real machine in the failure determination, and determine a cause of failure. Also, no cheap and practical diagnosis apparatus and method are provided. A plurality of instrumentation amounts concerning the refrigerant such as the pressure and temperature of the refrigerating cycle apparatus or other instrumentation amounts are detected, the state quantities such as composite variables are acquired by making the arithmetic operation on these instrumentation amounts, and whether the apparatus is normal or abnormal is judged employing the arithmetic operation results. If learning is made during the normal operation, a current state is judged, and if learning is made by compulsorily performing the abnormal operation, or if the abnormal operating condition is operated during the current operation, a failure foretaste such as a critical operation can be made from a change in the Mahalanobis distance. Thereby, the secure diagnosis can be implemented with a simple constitution.