The operation of a turbulence chamber diesel engine with LPG fumigation for exhaust emissions control

Abstract

An experimental study is conducted to evaluate the use of liquefied petroleum gas (LPG) as a secondary fuel for a Ricardo E-6, naturally aspirated, four-stroke diesel engine having a turbulence combustion chamber (indirect injection). The gaseous LPG is introduced together with the aspirated air (fumigation) at various proportions with respect to the diesel fuel which constitutes the main part. The influence of fuel feed ratios (LPG/diesel), in a vast range of loads, on fuel consumption, pressure diagrams, exhaust smokiness and exhaust gas emissions (nitrogen oxides, hydrocarbons and carbon monoxide) is investigated, the baseline being the single diesel fuel operation. The study for this type of engine, which has not being reported in the literature, shows a promise of the present method and reveals that above 60 per cent of maximum load the whole effect is beneficial concerning specific fuel consumption and smoke reduction. The examination of gaseous pollutant levels shows an involved relation with respect to load and fuel proportions. The best results (coupled to acceptable cylinder pressure levels) is obtained at a diesel fuel substitution value of 75% of maximum load, with an LPG mass fraction in the range 10 to 15%.