AIR CONDITIONER FOR VEHICLE

摘要

PROBLEM TO BE SOLVED: To accurately control pressure on the basis of temperature at an outlet side of an outside-of-vehicle side heat exchanger without additionally installing a temperature detecting means and a pressure detecting means. SOLUTION: An air conditioner for a vehicle comprises an internal heat exchanger 18 for heat exchange between a refrigerant between the outside-of- vehicle side heat exchanger 4 and a pressure reducing valve 9 and a refrigerant between an inside-of-vehicle side heat exchanger 10 and a compressor 1, a refrigerant pressure detecting means 8 for detecting pressure of the refrigerant at an outlet side of the heat exchanger 4, and a refrigerant temperature detecting means 7 for detecting the refrigerant temperature Tgco at an outlet side of the heat exchanger 4. A controlling means calculates the refrigerant temperature Tvi at an inlet side of the pressure reducing valve 9 on the basis of conditions including heat exchanging capacity of the heat exchanger 18 and the refrigerant temperature Tgco of at the outlet side of the heat exchanger 4, sets a target refrigerant pressure Phth of at the outlet side of the heat exchanger 4 on the basis of the temperature Tvi, and controls the opening of the valve 9 on the basis of the target pressure Phth and the actual refrigerant pressure Phgo detected by the pressure detecting means.