A Study of Chain Branching Termination Mechanism in HCCI Process

Abstract

Oxidation of dimethyl ether (DME) has been studied in motored internal combustion engine compression cycles. By applying a quadrupole mass spectrometer to monitor the exhaust gas composition, it was found that fuel consumption is limited at relatively constant extent in certain ranges of intake gas temperature and fuel-air ratio of the low temperature oxidation (LTO) regime, which is in good agreement with simulations using Curran's kinetic mechanism. It is suggested that inhibition of chain branching by piled up HCHO is responsible for this behavior. The features appeared in experiment and calculation can be explained by simplified LTO of DME and HCHO oxidation.