| 摘要 |
PROBLEM TO BE SOLVED: To improve energy saving property jumpingly and maintain the stabilized high degree of cooling accuracy. SOLUTION: The rotating frequency X of a compressor 2, constituting a refrigerating cycle, is changed by an inverter 3 within a given range Xd-Xu to control the temperature Tw of a work W to be cooled. When the temperature Tw is lowered to a temperature, unable to control by the inverter 3, the control of opening a hot gas bypass circuit 4 is effected. When the temperature Tw is increased in such state that the hot gas bypass circuit 4 is opened, the rotating frequency X of the compressor 2 is increased under a condition that the hot gas bypass circuit 4 is opened. When the rotating frequency X has arrived at a preset frequency Xs, the hot gas bypass circuit 4 is closed and the rotating frequency X of the compressor 2 is controlled so as to be reduced. |
