초록 ▼

A refrigerant cycle (16) for cooling as a prototype is provided with: an internal condenser (8) connected to a discharge circuit of an electric compressor (9) and disposed on a downstream of an internal evaporator (7) of an HVAC unit (2); a first heating circuit (18) connected to a receiver (11) thr

A refrigerant cycle (16) for cooling as a prototype is provided with: an internal condenser (8) connected to a discharge circuit of an electric compressor (9) and disposed on a downstream of an internal evaporator (7) of an HVAC unit (2); a first heating circuit (18) connected to a receiver (11) through a switching unit (17) arranged on an inlet side of the external condenser (8); and a second heating circuit (23) connected between an outlet side of the receiver (11) and a suction side of the electric compressor (9) and provided with a second expansion valve (20) and an external evaporator (21). A heat pump cycle (24) for heating is formed by a second heating circuit (23) including the electric compressor (9), the internal condenser (8), the switching unit (17), the first heating circuit (18), the receiver (11), the second expansion valve (20), and the external evaporator (21).

대표청구항 ▼

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 dis

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; anda 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, whereinthe 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, anda 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. 2. The heat-pump automotive air conditioner according to claim 1, wherein when the switch is made to the dehumidification heating using the internal evaporator, the heat-pump automotive air conditioner is operated in an inside air circulation mode or an inside air/outside air mixed mode. 3. The heat-pump automotive air conditioner according to claim 1, wherein the external evaporator is disposed in an air duct of an external fan for the external condenser, on a downstream of the external condenser and/or a vehicle radiator. 4. The heat-pump automotive air conditioner according to claim 1, wherein an auxiliary electric heater for heating is installed on an upstream of the internal evaporator in the HVAC unit, and when an amount of absorbed heat is insufficient during heating, the auxiliary electric heater can be activated to absorb the heat, and heat-pump heating mode is possible. 5. The heat-pump automotive air conditioner according to claim 1, wherein an internal heat exchanger that exchanges heat of a low-pressure gas refrigerant introduced to the electric compressor and a high-pressure liquid refrigerant from the receiver is arranged between intake piping of the electric compressor and outlet refrigerant piping of the receiver. 6. A method for defrosting the external evaporator in the heat-pump automotive air conditioner according to claim 1, wherein the method comprises operating the automotive air conditioner in the cooling cycle by setting a temperature regulation door of the HVAC unit to a maximum cooling position and setting an inside/outside air switch door to an inside air circulation mode when there is no passenger after termination of the vehicle,and defrosting the external evaporator by warm air heated by hot gas distributed to the external condenser. 7. The defrosting method of the heat-pump automotive air conditioner according to claim 6 wherein said method further comprises, performing a defrosting mode during or after charging of a vehicle battery when there is no passenger after the termination of the vehicle engine. 8. The defrosting method of the heat-pump automotive air conditioner according to claim 6, wherein said method further comprises in a defrosting mode, a blowoff mode of the HVAC unit is one of a def mode, a face mode, and a bilevel mode. 9. The defrosting method of the heat-pump automotive air conditioner according to claim 6, wherein said method further comprises activating an auxiliary heater when an internal temperature is low in a defrosting mode and having the internal evaporator absorbs the heat to improve defrosting performance. 10. The defrosting method of the heat-pump automotive air conditioner according to claim 6, wherein said method further comprises carrying out a heat-pump heating mode using the external evaporator to finish a defrosting mode and finishing the defrosting mode when a frost formation detection unit confirms that there is no frost formation.