Theoretical and Experimental Study on Leakage in CO_2 Rotary Expander

Study of leakage between high pressure and low pressure in CO2 rotary expander is important for improving the efficiency of expander.Based on the model of flat-plate leakage,the mechanism of supercritical leakage were given in CO2rotary expander.It is indicated that the lubricant oil film reduced the leakage gap and the leakage mass decreased by 40%.Toverify that the lubricant oil film exists and has influence on leakage volume,test piece was manufactured and test system was built.By the 5 μm,10 μm and 15 μm experiments,it is concluded that the lubricant oil film has remarkable effect on super-critical fluid leakage in expander.The flat-plate leakage model was then modified based on the experimental results,and the error is less than 6%.It can be used to analyze supercritical CO2 fluid leakage in expander containing lubricant oil.