| 摘要 |
PURPOSE:To effect cleaning work at any arbitrary time without any trouble even during the operation of the machine by a method wherein a pressure limiting device and a cold heat medium temperature control device are provided so that a condensing pressure will never exceed a predetermined value during the cleaning of the tubes. CONSTITUTION:The cold heat medium temperature control device 24 receives a brine outlet temperature signal from a temperature detector 13 and outputs a signal to operate a capacity valve 25. The pressure limiting device 26 detects the internal pressure of the condenser 5 and outputs a signal to operate the capacity valve 25 so as to obtain the internal pressure lower than a predetermined pressure. A changeover device 23 is equipped with a switch mechanism 27 and when the internal pressure of the condenser 5 is lower than a predetermined value, a contact T is conducted and the cold heat medium temperature control is effected, while the contact P is conducted, the pressure limiting control is effected and the abnormal rise of the internal pressure of condenser 5 is prevented when the pressure has exceeded the predetermined value. Accordingly, even if the flow path is switched to effect the cleaning of the condenser tubes during the operation of the refrigerating machine, the internal pressure of the condenser will never be risen abnormally, the overload of motor or high pressure trip will never be caused, surging will never be generated in the centrifugal type compressor, it is safe, noise or vibration will never be caused and the cleaning work may be effected at any arbitrary time. |
