Detailed chemical kinetic simulation of natural gas HCCI combustion: Gas composition effects and investigation of control strategies

This paper uses the HCT (hydrodynamics, chemistry and transport) chemical k inetics code to analyze natural gas combustion in an HCCI engine. The HCT c ode has been modified to better represent the conditions existing inside an engine, including a wall heat transfer correlation. Combustion control and low power output per displacement remain as two of the biggest challenges to obtaining satisfactory performance out of an HCCI engine, and these chal lenges are addressed in this paper. The paper considers the effect of natur al gas composition on HCCI combustion, and then explores three control stra tegies for HCCI engines: DME (dimethyl ether) addition, intake heating and hot EGR addition. The results show that HCCI combustion is sensitive to nat ural gas composition and an active control may be required to compensate fo r possible changes in composition. Each control strategy has been evaluated for its influence on the performance of an HCCI engine.