HEAT PUMP TYPE AIR CONDITIONER FOR VEHICLE

PURPOSE:To prevent an outdoor heat exchanger from being frosted in heating operation by providing a heat source, by which refrigerant in an accumulator is heated in heating operation, on the accumulator being a part of the titled air conditioner. CONSTITUTION:A heat pump cycle is composed of a compressor 1, a four- directional change-over valve 2, an outdoor heat exchanger 3, a pressure reducing mechanism 11, an indoor heat exchanger 9, and an accumulator 10. In heating operation, hot and high-pressure gas refrigerant is guided to flow from the compressor in the direction of dotted line, exchanges heat with air in the indoor heat exchanger 9 to increase heating effect, and then is returned back to the compressor 1 through the pressure reducing mechanism 11, the outdoor heat exchanger 3, and accumulator 10. In this case, a heater 13 is provided on the accumulator 10 and the refrigerant is heated by the heater 13 to raise the saturation pressure of the refrigerant, whereby the evaporating pressure of the refrigerant is raised in the outdoor heat exchanger 3 to suppress frosting on the outdoor heat exchanger 3.