Patent ID: 6614353
Filing Date: 2003-09-02
Classification: F25B,F25D,H05K,Y10T

Abstract:
A predictive maintenance system for a constant temperature fluid circulating apparatus, comprising:a refrigeration circuit for cooling via a heat exchanger a cooling liquid which is circulated through a load; a coolant circulating circuit, including a proportional valve and a heater disposed in a tank, for applying heat to and adjusting to a preset temperature the cooling liquid which has been cooled in said heat exchanger, and outputting said cooling liquid, wherein a constant temperature cooling liquid is circulated with respect to said load; the system further comprising: sensors for continuously monitoring, in respective parts of said constant temperature fluid circulating apparatus, various condition amounts, wherein parts requiring maintenance and maintenance time intervals are inferred from the condition amounts of the respective parts in the apparatus which are obtained as outputs from said sensors, said sensors including means for detecting a degree of opening of said proportional valve through which said cooling liquid is supplied to said tank in said cooling liquid circulating circuit; and warning means for issuing a warning before a breakdown or irregular operation occurs, when said degree of opening of said proportional valve exceeds a predetermined percentage.