PURPOSE: To obtain a thermal expansion valve provided with a controller which can directly electrically detect the saturation temperature of a refrigerant by making a microprocessor generate an electric control signal from a characteristic retrieval table for the refrigerant and rotating a compressor when the saturation pressure decided from the retrieval table does not fall within a desired range.
CONSTITUTION: A cooling apparatus, which detects the saturation temperature at its high-pressure inlet by means of a self-heating thermistor 42, and detects the saturation temperature at the outlet of an evaporator 34 by means of a second thermistor 88, is constituted by using a mechanical thermal expansion valve 30. A controller 64 based on a microprocessor sends an output signal which rotates a condenser fan 24 to a relay correspondingly to the high-pressure side pressure, or another output signal which rotates a compressor clutch 14 to the relay correspondingly to the low- pressure side temperature by comparing the detected temperatures with stored critical values. For an evaporator causing a small pressure drop, the second thermistor 88 can be arranged at the inlet of the evaporator 34. Therefore, the high-pressure side saturation pressure of the thermal expansion valve 30 can be decided without requiring any separate pressure switch.
MAIKERU BII TONPUSON
ROBAATO JIEE TOORENSU
MAABIN EFU GAUDETSUTE
