发动机余热回收用涡旋膨胀机涡旋盘变形分析

A scroll expander of involute of circle with variable radii was proposed according to the flow field in working chambers and deformation characteristics of the conventional scroll profile. The proposed scroll expander has the same basic geometric parameters as the conventional scroll expander and was used in the waste heat recovery system of organic Rankine cycles(ORC) of a vehicle engine. Compared to the conventional scroll profile, the involute of circle with variable radii reduces the frictions of gas parcels and the mechanical energy loss, weakens the secondary flow losses in both sides of the back pressure chamber, and makes the pressure and temperature distributions of the exhaust chambers and the back pressure chambers more uniform. The scroll expander with the involute of circle and variable radii has the same working ability as the scroll expander with the conventional scroll profile. Furthermore, the scroll expander with the involute of circle and variable radii has smaller space of the working chambers, higher isentropic efficiency and smaller deformation.