CO2转子膨胀机泄漏的理论及实验

研究CO2转子膨胀机内高低压间泄漏问题是提高膨胀机效率的途径之一．笔者结合转子膨胀机内常用的平板泄漏模型进行了超临界泄漏的机理分析，结果表明泄漏通道表面形成的油膜使泄漏通道间隙减少，泄漏量降低40％．研制了超临界CO2流体泄漏试件，建立了泄漏实验装置，进行了超临界流体微小通道5μm、10μm和15μm泄漏实验，验证了润滑油对泄漏的影响．实验数据表明，润滑油时膨胀机内部超临界流体泄漏有显著的影响．根据实验结果修正了已有的平板泄漏模型，误差在6％之内．该模型适用于含润滑油的超临界CO2泄漏分析．

Theoretical and Experimental Study on Leakage in CO2 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 CO2 rotary expander. It is indicated that the lubricant oil film reduced the leakage gap and the leakage mass decreased by 40%. To verify that the lubricant oil film exists and has influence on leakage volume, test piece was manufactured and test system was built. By the 5μm, 10μm and 15μm experiments, it is concluded that the lubricant oil film has remarkable effect on supercritical 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.