HEAT PUMP AIR CONDITIONER

摘要

PROBLEM TO BE SOLVED: To enhance durability of the compressor in a heat pump air conditioner by improving the lubricating ability of the compressor. SOLUTION: Gas-liquid refrigerant passed through an outdoor heat exchanger 26 under heating mode is separated through an accumulator 24 and liquid refrigerant dissolved with oil is sucked from an oil return hole 25b made closely to the bottom part of the accumulator 24 and fed to a compressor 21 after being mixed with gas refrigerant. In such a heat pump air conditioner, delivery capacity of the compressor 21 is lowered forcibly below a normal target capacity when a decision is made that the liquid level of refrigerant in the accumulator 24 lowers abruptly toward the oil return hole 25b at the time of starting the heating mode.