Abstract
Keywords: LPG (Liquefied Petroleum Gas), Compressed Ignition, Cetane Number, Ignition Delay, Constant Volume Chamber
This research investigated spray and combustion characteristics of compressed ignition type LPG fuel at various additive ratios for enhancing cetane number in a constant volume chamber. Since LPG fuel has a low cetane number, di-tert-butyl peroxide (DTBP) and alpha olefin were added to the LPG (100% butane) to enhance cetane number and lubrication in LPG fuel. The addition of these cetane enhancers makes possible to provide stable combustion over wide ranges of the ambient conditions.
In order to investigate spray and combustion progress of LPG fuel, pre-mixed combustion was made by the mixture of hydrogen, oxygen and nitrogen under the ambient condition of high pressure and temperature and then liquefied LPG was injected directly to a constant volume chamber. For the visualization of the combustion process by LPG fuel, high speed digital camera was applied.
It turned out that exhaust emissions particularly in carbon monoxide and hydrocarbon were reduced considerably by adding DTBP and alpha olefin. Compared to other cases of blended LPG fuel, hydrocarbon emission decreased much more in LPG blended fuel of 15 wt% of DTBP.