Vehicle air conditioner with vapor-compression refrigerant cycle

An air conditioner for a compartment, comprising:

• a compressor for compressing and discharging refrigerant;
• a decompression unit that decompresses high-temperature refrigerant discharged from the compressor;
• an exterior heat exchanger for performing heat exchange between refrigerant and outside air outside the compartment;
• an interior heat exchanger for performing heat exchange between refrigerant and air to be blown into the compartment, wherein the interior heat exchanger and the exterior heat exchanger are disposed such that heat from low-temperature refrigerant in one of the interior heat exchanger and the exterior heat exchanger is moved to the high-temperature refrigerant in the other one thereof by evaporation of refrigerant after being decompressed in the decompression unit;
• and
• a heater disposed to heat air to be blown into the compartment using the high-temperature refrigerant before being decompressed as a heating source;
• wherein the decompression unit includes
• an ejector for decompressing refrigerant discharged from the compressor while sucking gas refrigerant from the interior heat exchanger, and for converting expansion energy to pressure energy to increase pressure of refrigerant to be sucked to the compressor, and
• first and second throttles for decompressing refrigerant in substantially iso-enthalpy,
• the air conditioner further comprising
• a switching unit for changing a refrigerant flow to switch one of a first operation where the compartment is cooled, a second operation where the compartment is dehumidified while being heated, and a third operation where the compartment is heated, wherein:
• in the first operation, refrigerant after being decompressed is evaporated in the interior heat exchanger to cool air passing therethrough, and high-pressure refrigerant discharged from the compressor is decompressed in the ejector while sucking gas refrigerant from the interior heat exchanger;
• in the second operation, refrigerant after being decompressed is evaporated in the interior heat exchanger to cool and dehumidify air passing therethrough, and high-pressure refrigerant discharged from the compressor is decompressed by the first throttle;
• and
• in the third operation, high-temperature refrigerant before being decompressed flows into the interior heat exchanger to heat air passing therethrough, and the high-pressure refrigerant is decompressed in the second throttle.