Development and bench-testing of a common rail system for dimethyl ether

Dimethyl ether (DME) offers great potential benefits in reducing exhaust emissions and improving the fuel economy of automotive engines, but it requires a different fuel system to deal with its physical properties. In the present study, a new electronically controlled common rail injection system was specially designed to resolve this issue. The mechanism and principle of this system was described in detail. Experimental work has been carried out to examine and improve matching of the fuel injection system on a fuel injection pump test bench. The results show that the orifice diameter in the three-way connector of the new fuel system has significant effects on injection performance, and a diameter of 0.3 mm has been proven to be most appropriate for the system. The effect of the pressure in the middle-pressure common rail (MPCR) on the injection characteristics has also been studied. When the pressure in the MPCR is 6.0 MPa, the present system has demonstrated good injection characteristics.