Air-conditioning device for electric automobiles

An air-conditioning device for electric automobiles powered by a power source of secondary batteries, comprising:

• an internal heat exchanger installed in a blast duct that sends air into a passenger compartment;
• an external heat exchanger for exchanging heat with external air;
• a compressor provided in a coolant circulation circuit that includes said internal heat exchanger and said external heat exchanger, and compresses a coolant;
• and
• an electric motor which is rotated by the power source of said secondary batteries to drive said compressor;
• wherein,
• during a heating operation, the coolant supplied from said compressor is fed to an internal condenser, while during a cooling operation, the coolant which has been condensed by said external heat exchanger and decompressed by a decompression device, is supplied to said internal heat exchanger, so that said internal heat exchanger works as a source of heat;
• said air-conditioning device for electric automobiles further comprising:
• a frost judging means which judges the formation of frost on said external heat exchanger;
• and
• a first defrosting means which is so constituted as to circulate the coolant in the order of said compressor, said internal condenser installed in the blast duct that sends the air into the passenger compartment, said external heat exchanger, said decompression device, and the internal heat exchanger, and
• a second defrosting means which is so constituted as to circulate the coolant in the order of said compressor, said external heat exchanger, said decompression device and the internal heat exchanger.