Patent ID: 9222710
Filing Date: 2015-12-29
Classification: B60H,F25B

Abstract:
1. A heat-pump automotive air conditioner comprising: a refrigerant cycle for cooling, to which an electric compressor, an external condenser, a receiver, a first expansion valve, and an internal evaporator arranged in an HVAC unit are connected in this order; an internal condenser connected to a discharge circuit of the electric compressor and disposed on a downstream of the internal evaporator in the HVAC unit; a first heating circuit connected to the receiver through a switching unit arranged on an inlet side of the external condenser; and a second heating circuit connected between an outlet of the receiver and a suction side of the electric compressor and provided with a second expansion valve and an external evaporator, wherein the electric compressor, the internal condenser, the switching unit, the first heating circuit, the receiver, and the second heating circuit having the second expansion valve and the external evaporator form a heat pump cycle for heating, the heat-pump automotive air conditioner further comprising: a sensor configured to detect frost formation on the external evaporator; a first on/off valve for closing/opening a channel which allows refrigerant to flow from the receiver to the second expansion valve; a second on/off valve for closing/opening a channel which allows the refrigerant to flow from the receiver to the electric compressor through the internal evaporator, and a controller configured to determine the frost formation on the basis of detection of the sensor during the heating operation with the heat pump cycle, and configured to close the first on/off valve and open the second on/off valve when the frost formation is detected, and thereby prevent the refrigerant from flowing into the second heating circuit and allow the refrigerant to flow into the internal evaporator.