Emissions From a Compression Ignition Engine Fuelled on DME
Previously reported results have shown that the performance of a compression ignition engine fuelled on DME is similar to that achieved with diesel fuelling. The present work concentrates on emissions with particular reference to NOx. This research was performed keeping injection timing and injector opening pressures the same for both diesel and dimethyl ether fuelling. Tests were performed with both fuels at three loads, with speeds ranging from 1100 to 1800 rpm. Analysis of the results indicates that in terms of performance, similar results were achieved with both fuels. With regard to specific NOx emissions, these were observed to be higher than those from the corresponding diesel tests at lower speeds, but were found to decrease as speed increased. However, from 1600 rpm emissions for DME fuelling were less than those of diesel fuelling. This pattern was found to occur at all loads tested. In this paper some of the factors contributing to the higher than expected NOx emissions are discussed and analyzed.