rotary compressor; variable speed; large displacement; P-V diagram; efficiency
In order to deeply understand the internal thermodynamic process of a variable speed rotary compressor with large displacement, the P-V diagram was measured as an important way to analyze efficiencies of the compressor. A testing compressor was modified for measurement of the internal dynamic pressure and performance. The compressor was tested under different operating conditions, and the P-V diagram was finally obtained. Based on the test results, efficiencies of the compressor can be estimated accurately, which could be used to optimize the compressor structure parameters.