涡旋膨胀机异形修正型线的进气口优化分析

OPTIMIZATION ANALYSIS OF THE SCROLL EXPANDER SPECIAL TOP PROFILE CORRECTION IN THE INLET PORT

从提高涡旋膨胀机气动功率转化效率出发,通过分析涡旋膨胀机中常用的PMP修正型线在应用中所产生的齿头入侵进气口严重的问题(最大入侵率达50%),导致进气口处气流摩擦因数增大。所以,在双圆弧加直线齿头修正型线的基础上,提出一种涡旋齿头异形修正型线的方法。根据异形齿头修正型线的特点,得出异形齿头修正型线的齿头入侵率低(最大入侵率仅为9%),进气口处气流摩擦因数小。此外,在进气过程中,任意时刻的实际进气口能够保持相对圆滑,从而减少进气口处气流摩擦因数,降低了进气口功率损耗。并且可实现涡旋膨胀机对称同步膨胀,从而达到功率平稳输出、减少机械振动的效果。因此,从理论上减少膨胀进气口功率损失,提高了涡旋膨胀机气动功率转化效率。

The study has been done with focus on the pneumatic power conversion efficiency by analyzing Perfect Meshing Profile （PMP） correction of the scroll expander with the serious top profile invasion of the inlet port problem in application. The maximal invasion rate reaches 50% , which leads to the increase of inlet air flow friction coefficient. Therefore, on the basis of the circular arc plus line-shaped top profile correction, special correction method for the top profile was proposed. According to the feature of special top profile correction method, it comes to a conclusion that special top profile correction has low invasion rate （the maximum only was 9% ） and airflow friction coefficient of the inlet port decreases. In addition, in the intake process, at any time the actual inlet port can remain relatively smoothly, therefore reducing the airstream friction coefficient and the inlet port power loss. And what＇ s more, symmetric synchronous inflation of scroll expander has been accomplished, and consequently the results are smooth power delivery with reducing the mechanical vibration. Theoretically, the scroll expander pneumatic power conversion efficiency has been improved by reducing inlet port inflation power loss.