| 摘要 |
PURPOSE:To prevent excessive cooling in the high rotation range of a compressor by controlling the opening of an expansion valve so that the superheat value agrees with the optimum cooling superheat value in accordance with the number of revolution of the compressor. CONSTITUTION:In a superheating control unit 13, the superheat value is obtained from the difference between the exit temp. theta and the entrance temp. I in an evaporator 5 through temp. sensors 15 and 14, this set value is varied in accordance with the number of revolution S of a compressor obtained from a detector 16, and the opening of an electrical expansion valve 4a is increased or decreased according to the optimum cooling superheating value and the detected superheating value. This optimum cooling superheating value which serves as the standard of control is set a little higher in the high rotation range of the compressor 1 than the value in the low rotation range, to prevent excessive cooling in the high rotation range operation of compressor, continuously providing a comfortable air conditioning. |
