The Effect of Operating Parameters on Dual Fuel Engine Performance and Emissions – An Overview

In order to decrease harmful exhaust gas emissions from internal combustion engines, researchers are continuously looking for alternative fuels and combustion techniques, and in this context the use of natural gas as a supplement for conventional fuels has been suggested. Since natural gas has high autoignition temperature, it cannot be used in compression ignition engines as the in-cylinder temperature around the top dead center is simply not high enough to ignite it. Therefore, in such an application natural gas has to be used with high reactivity fuel, usually diesel fuel. In these applications diesel fuel is used solely as a high energy ignition device, while natural gas is used as primary fuel. This type of combustion process is called dual fuel combustion process. This paper presents the effect of operating parameters, such as diesel fuel injection pressure, injection timing, diesel fuel mass, diesel fuel substitution ratio and intake charge conditioning, as well as engine load and speed on efficiency and harmful exhaust gas emissions from dual fuel diesel/natural gas internal combustion engines