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.