Dual fuel diesel combustion with an E85 ethanol/gasoline blend

Abstract

In this experimental study, the ethanol/gasoline blend E85 was used as the primary fuel in a dual-fuel combustion concept. The E85 blend was injected at low pressure into the intake manifold and the mixture was ignited via a diesel fuel injection near top dead centre. The research engine was based on a heavy-duty diesel engine equipped with a common-rail injection system. Only the duration of the diesel injection was modified in the diesel injection system during the tests-the other diesel injection parameters were not changed. The goal was to study the possibilities of using the waste material-based E85 ethanol blend on dual-fuel concept as a promising future bio-fuel option. The results were promising, though the engine was not optimised for the combustion concept being studied and minimum modifications were done to the engine. High E85 rates (up to 89%) by energy content were achieved, especially under medium load conditions. On the high and low load portions were lower, but the E85 rates were higher than 30% even in these cases. For most of the cases, the limiting issue was the pressure rise rate, but in cases with the highest portions of E85 the limiting factor was the minimum quantity of the diesel fuel enabling two phase diesel fuel injection. In all cases the E85 increased carbon-monoxide and un-burned hydrocarbon emission, but the nitrogen oxide emission decreased simultaneously in most of the cases. Smoke emissions were low in all cases, but at highest E85 rate smoke emissions further decreased to near zero value.

Effects of direct injection timing and blending ratio on RCCI combustion with different low reactivity fuels

“…Taking into account this statement, it is clear that the low reactivity fuel characteristics and its amount in the blend have a significant contribution to the incylinder reactivity, and therefore, to the combustion development and its emissions. In this sense, recent works investigated the use of E85 fuel as alternative of gasoline on RCCI concept [24][25] [26] [27]. In terms of emissions, the use of E85 resulted in increased HC and CO levels with decreased NOx.…”

Experimental and numerical study of lift-off length and ignition delay of a two-component diesel surrogate

“…To this end, engine research and development groups have been trying for decades to better understand and describe the fundamentals of these processes, including alternative fuels and combustion strategies [2] [3]. Both experimental and computational approaches have brought important insight towards enhancing our understanding of the global and local processes governing fuel mixing and combustion.…”

Experimental and numerical investigations on the combustion and emission characteristics of an ethanol/diesel dual-fuel engine

“…Studies have shown that dual-fuel PCI combustion with ethanol premixed, ultra-low soot and NOx emissions can be realized with nearly 60% indicated thermal efficiency [9]- [14]. It is also found that dual fuel engines are often observed with large cyclic variations.…”