Air conditioner for vehicle

An air conditioner for a vehicle, comprising:

• refrigerant;
• a compressor applying a workload to said refrigerant, said compressor having a refrigerant suction side and a refrigerant discharge side;
• an outer heat exchanger transmitting heat between said refrigerant and ambient air, said outer heat exchanger having a first side and a second side;
• a blower leading air for air-conditioning a passenger compartment of the vehicle;
• a heat-radiating inner heat exchanger transmitting the heat of said refrigerant to the air led by said blower, said heat-radiating inner heat exchanger having a refrigerant inlet side and a refrigerant outlet side;
• an expansion valve adiabatically expanding said refrigerant, said expansion value having a refrigerant inlet side and a refrigerant outlet side;
• a heat-absorbing inner heat exchanger transmitting the heat of the air led by said blower to said refrigerant, said heat-absorbing inner heat exchanger having a refrigerant inlet side and a refrigerant outlet side;
• and
• refrigerant passage switching means for setting a refrigeration cycle to one of a cooling mode, a heating mode and a weak heating mode, said refrigerant passage switching means including a plurality of series auxiliary conduits which connect said heat-absorbing inner heat exchanger and said outer heat exchanger in series during the weak heating mode,
• in the cooling mode, said refrigerant flowing in the order of said compressor, said outer heat exchanger, said expansion valve, said heat-absorbing inner heat exchanger and said compressor,
• in the heating mode, said refrigerant flowing in the order of said compressor, said heat-radiating inner heat exchanger, said expansion valve, said heat-absorbing inner heat exchanger and said compressor while bypassing said outer heat exchanger, and
• in the weak heating mode, said refrigerant flowing in the order of said compressor, said heat-radiating inner heat exchanger, said expansion valve, said outer heat exchanger and said compressor.

An air conditioner for a vehicle, comprising:

• refrigerant;
• a compressor applying a workload to said refrigerant, said compressor having a refrigerant suction side and a refrigerant discharge side;
• an outer heat exchanger transmitting heat between said refrigerant and ambient air, said outer heat exchanger having a first side and a second side;
• a blower leading air for air-conditioning a passenger compartment of the vehicle;
• a heat-radiating inner heat exchanger transmitting the heat of said refrigerant to the air led by said blower, said heat-radiating inner heat exchanger having a refrigerant inlet side and a refrigerant outlet side;
• an expansion valve adiabatically expanding said refrigerant, said expansion valve having a refrigerant inlet side and a refrigerant outlet side;
• a heat-absorbing inner heat exchanger transmitting the heat of the air led by said blower to said refrigerant, said heat-absorbing inner heat exchanger having a refrigerant inlet side and a refrigerant outlet side;
• an inner thermal condition detecting means for detecting a thermal condition of the passenger compartment and for outputting a signal indicative of said thermal condition;
• an inner thermal condition setting means for setting a desired thermal condition of the passenger compartment by means of a setting operation by a driver of the vehicle;
• and
• refrigerant passage switching means for switching a refrigerant flow among said compressor, said outer heat exchanger, Said heat-radiating inner heat exchanger, said expansion valve and said heat-absorbing inner heat exchanger, said refrigerant passage switching means setting a refrigeration cycle to one of a cooling mode, a first heating mode and a second heating mode according to said signal output from said inner thermal condition detecting means and said inner thermal condition setting means, the first heating mode being a main heating operation for strongly heating the passenger compartment, and the second heating mode being a weak heating operation for weakly heating the passenger compartment.