When the two-stage compression cycle coupled with dual-cylinder rolling piston compressor is used in the room air conditioner with the refrigerant of R410A

its heating/cooling capacity can be remarkably improved and the discharge temperature can be reduced.By analyzing thermodynamically the two-stage compression heat pump system coupled with dual-cylinder rolling piston compressor

simulated calculation indicated that the favorable volume ratio of higher-pressure chamber to lower pressure one was 4/5.The experiments for the developed prototype were conducted.The experimental results showed that the coefficient of performance(COP)for cooling conditions could go up to 3.81 and discharge temperature was lower than 91℃ when evaporating temperature kept 5℃ and condensing temperature varied from 35℃ to 45℃

and COP for heating conditions could rise up to 3.38 and discharge temperature was lower than 111℃ when condensing temperature was 40℃ and evaporating temperature varied from -5℃ to -10℃.COP could be improved by 6.8%—15.4% when compared with one-stage compression cycle.