| 摘要 |
PROBLEM TO BE SOLVED: To improve energy-saving performance and controllability by stably controlling temperature of cooling liquid to obtain accurate stable cooling temperature, and improving operation efficiency over the whole. SOLUTION: A refrigeration cycle 2 is provided with a digital controlled refrigerant compressor 6 provided with a digital selecting mechanism 5 for selecting load condition for compressing refrigerant when a compressor motor 4 is operated and unload condition for releasing compression of the refrigerant when the compressor motor 4 is operated. A target over-heating degree is previously obtained on the basis of load ratio Rr of the digital controlled refrigerant cooling device 6 and temperature (liquid temperature Tw) of a cooling liquid W to be supplied to a material M to be cooled, and a reference opening N of an electronic expansion valve 7 is set to obtain the target over-heating degree, and during the operation, the liquid temperature Tw and the load ratio Rr are detected, and the electronic expansion valve 7 is controlled to obtain the reference opening N corresponding to the liquid temperature Tw and the load ration Rr. COPYRIGHT: (C)2006,JPO&NCIPI
|
