两级旋叶式膨胀机动力特性的理论研究

Theoretical Research on Dynamic Characteristic of Rotary Vane Expander

两级旋叶式膨胀机与传统旋叶式膨胀机在结构上有着明显的差别,能够实现更高的容积膨胀比,适合用于R410A等具有较高膨胀比的制冷系统。本文通过对两级旋叶式膨胀机运动和受力特征的分析,建立了滑片的受力模型,并应用该模型对拟开发的两级旋叶式膨胀机进行动力计算,分析比较了滑片的运动和所受各种力的计算结果,重点讨论了背压对滑片顶部与气缸壁面间接触力的影响,得出将滑片两侧工作腔中高压腔内工质引入背压腔的方法更适合于两级旋叶式膨胀机。

There are significant differences between the two-stage rotary vane expander and the traditional one, the two-stage rtary vane expander can reach higher volumetric expansion ratio, and is suitable for the refrigeration system with R410A as refrigerant, which possesses high expansion ratio. A dynamic model of the vane was developed by analyzing the characteristics of the motion and forces of the two-stage rotary vane expander. Utilized this model for dynamic calculation in this new type of expander, analyzed the results of the motion and forces of the vane, especially the influence of the back pressure on the contact force between the top of vane and inner cylinder wall, and concluded that by introducing the refrigerant from the higher pressure expansion chamber, one of the two expansion chambers besides the vane which has a higher pressure, to the back pressure chamber is a proper way for two-stage rotary vane expander.