| 摘要 |
<p>PROBLEM TO BE SOLVED: To secure an amount of an oil returning from an oil separator 28 to a fourth compression part 24 even when a difference between a suction pressure and a discharge pressure of the fourth compression part 24 is small.SOLUTION: An air conditioner 10 includes: a four stage compressor 20; an outdoor heat exchanger 40; an expansion mechanism 70; an indoor heat exchanger 12a; an oil separator 28; oil return passages 28a, 28b; and an oil return bypass electromagnetic valve SV28. In the four stage compressor 20, multiple low stage compression parts 21, 22, 23 and one high stage fourth compression part 24 are connected in one line. The oil separator 28 is provided at a fourth discharge pipe 24b. The oil return passages 28a, 28b connect a fourth suction tube 24a with the oil separator 28 and return an oil from the oil separator 28 to the fourth compression part 24. The oil return bypass electromagnetic valve SV28 changes passage areas of the oil return passages 28a, 28b.</p> |
