A study on the auto ignition characteristics of DME-LPG dual fuel in HCCI engine

Abstract

Paper presented to the 10th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Florida, 14-16 July 2014.This study was investigated to examine the potential increase of engine power through the mixture of di-methyl ether (DME) and liquefied petroleum gas (LPG) on homogeneous charge compression ignition (HCCI) combustion. The effects of mixing ratio of DME/LPG in constant intake temperature were confirmed experimentally in a single cylinder diesel engine. A numerical analysis were conducted through the mixing model of DME and n-Butane for the detailed chemical kinetics using CHEMKIN-PRO to clarify the autoignition mechanism of constant combustion phasing. The results show that the increased amount of LPG reduces the low temperature heat release (LTHR) and activates the high temperature heat release (HTHR) which increases the in-cylinder pressure. Therefore, it has potential to raise the indicated mean effective pressure (IMEP) by appropriately changing the mixing ratio. Also, thermal efficiency was increased to 51.2% at the mixing ratio of 0.6. Finally, engine out emissions including total hydrocarbon (THC) and carbon monoxide (CO) were decreased by the change of mixing ratio. Numerical results agreed with experiment that the weakened low temperature oxidation by the increase of n-Butane amount.