Dual fuel operating strategy offers great opportunity to reduce
emissions like particulate matter and NOx from compression ignition
engine and use of clearer fuels like natural gas. Dual-fuel engines
have number of potential advantages like fuel flexibility, lower
emissions, higher compression ratio, better efficiency and easy
conversion of existing diesel engines without major hardware
modifications. In view of energy depletion and environmental
pollution, dual-fuel technology has caught attention of
researchers. It is an ecological and efficient combustion
technology.
This paper summarizes a review of recent research on dual-fuel
technology and future scope of research. Paper also throws light on
present limitations and drawbacks of dual-fuel engines and proposed
methods to overcome these drawbacks. A parametric study of
different engine-operating variables affecting performance of
diesel-CNG dual-fuel engines vis-à-vis base diesel operation is
also summarized here. Chemical kinetic and CFD simulation of
dual-fuel diesel-CNG engine combustion has been carried out based
on available literature data.
Thereafter, experimental results of effect of gas supplement
ratio (fraction of natural gas in total fuel, on mass basis) on
emission and performance characteristics of a six-cylinder
heavy-duty compression ignition engine have been discussed with an
aim of understanding the engine behavior under dual-fuel operating
mode.