To eliminate a dispersion between refrigerator units by controlling a temperature of the individual refrigerator unit, to make efficient a refrigerator system (the whole of refrigerator-compressor), and to save electric power.
In this operation method for a cryogenic refrigerator constituted of the plurality of refrigerator units independent each other, and the one or plurality of compressors, a rotational speed of the compressor is regulated to make constant a pressure difference between high pressure in a compressor delivery port side and low pressure in a compressor suction port side, a cycle time of suction-exhaust is prolonged in a refrigerator of low thermal load, out of the plurality of refrigerators, the cycle time of suction-exhaust is shortened in the refrigerator of high thermal load, so as to be regulated in the desired temperature, and the rotational speed of the compressor is further regulated again to make constant the pressure difference varied in response to a gas flow rate varied accompanied thereto.
COPYRIGHT: (C)2008,JPO&INPIT
Tsuyoshi Makino
Keisuke Matsuyama