Analysis of a production-oriented air hybrid engine concept and its performance

Abstract

In this paper, an air hybrid engine concept with an one-way intake system will be described and analysed. The investigation started with systematic studies on the effect of various valve opening and closing events on the performance of Compressor Mode (CM) and Expander Mode (EM) operations. After having defined the optimal valve timings for CM and EM operations over a range of engine speeds, the effect of other operating parameters on the performance of the air hybrid engine, such as buffer (or auxiliary) chamber volume, airtank volume and pressure, etc., is examined. It is shown that this concept can be readily implemented in production engines with existing production VVA technologies. The predicted results indicate that it is capable of performing good regenerative braking and large driving torque to start and motor the engines using the stored compressed air.