The Effects of Initial Conditions on the Composition of the On-Board Fuel Reformation Chamber in an HCCI Engine

Abstract

Based on the CHEMKIN software, a model of the reforming chamber was built to simulate the on-board fuel reforming process in a Homogeneous Charge Compression Ignition (HCCI) engine. The effects of the initial pressure and temperature of the chamber on the reformed gas were studied. The results show that the main species in the reformed gas are H2 and CO. This paper investigated the effect of initial temperature on the reformed gas, in order to get the optimum initial temperature. Under the optimum initial temperature (1300 K), some important conclusions have been drawn by changing initial pressures of the chamber. Initial pressure may have great effect on other species, but has a small effect on mole fractions of H2 and CO. By comparing the concentrations of H2 and CO between low and high initial pressures under the optimum initial temperature, it can be concluded that H2 and CO are still the main species in the reformed gas.