CO2跨临界循环滚动活塞膨胀机的研究与开发--试验测试部分

为提高CO2跨临界循环的效率，降低系统的节流损失，用CO2膨胀机代替系统中的节流阀，并对其回收膨胀功进行了研究，设计和开发了两代CO2滚动活塞膨胀机样机，给出了两代CO2膨胀机的特点，同时进行了试验对比．试验测试结果表明滚动活塞形式的膨胀机在超临界和两相区运行是可行的．第二代膨胀机明显优于第一代膨胀机，可见采取的降低泄漏、减小摩擦等措施非常有效．膨胀机在CO2跨临界循环中运行，存在最佳转速，使膨胀机的输出功率达到最大。

Research and Development of Rolling Piston Expander in CO2 Transcritical Cycle—Experimental Part

The replacement of the throttle valve with CO_2 expander in the system and the expansion work recovery were studied for the improvement of the coefficient of performance of the CO_2 transcritical cycle and reduction of the throttling energy loss.The prototypes of two-generation CO_2 rolling piston expanders were designed and developed.Their different characteristics were presented and the experimental comparisons of two expanders are conducted.The test results indicate the operability of the rolling piston expander in the supercritical two-phase region.The results show that the performance of the second generation rolling piston expander is better than the first one due to the improvement,and is that the (activities) measurements for minimum leakage and friction are powerful.There exists the optimal revolution speed of the expander in the CO_2 transcritical cycle to make the maximum power output produced from the expander.Hovever, there are still many problems in the design of rolling piston expander,especially the vane.A new type of vane is needed to decrease the friction between the vane and cylinder.