An Analysis of Characteristics on a Helical Screw Expander Considering Dynamic Behaviors.

Abstract

Helical Screw Expander is a positive displacement type fluid machine. So far, steady simulation methods were carrided out to get quantities of state between the lobes, where the internal leakage is occurred. In these simulations, quantities of state hold constant values in the admission process. However, the disagreements between the simulation and the experimental results are extended at the higher rotor speed. Therefore, the simulation method has to consider the dynamic behaviors at the admission process. In this work, the bondgraphs technique was used to predict the dynamic behavior. Hence, the bondgraphs method improved the evaluation of the performance, especially at the higher region of the rotor peripheral speed. Consequently, the effectiveness of the bondgraphs method to predict the performance on a helical screw expander is confirmed.