Study on the performance and emissions of a compression ignition engine fuelled with dimethyl ether

The paper presents the research results of a light-duty direct injection di esel engine operating on dimethyl ether (DME). The effects of the main para meters of the combustion system, such as plunger diameter, nozzle type, fue l delivery advance angle, protruding distance of the nozzle tip from the bo ttom plane of the cylinder head and swirl ratio, on the performance of the DME engine are investigated. The indicator diagrams are taken after optimiz ing the combustion system and characteristics of combustion and emissions a re measured for DME and diesel operation. The results show that, by adding a pressure pump in the fuel supply system, the vapour lock of DME in the fu el system is eliminated. The engine runs smoothly on DME over a wide range of speeds and loads. The effective thermal efficiency of the DME engine is 3 per cent higher than that of the diesel engine, and a low rate of pressur e rise, low combustion noise, smokeless combustion and low NO, emissions of the DME engine can be achieved. The results demonstrate good characteristi cs in reducing emissions for a diesel engine operating on DME.