Experimental Research On Plunger Matching Parts Of Injection Pump Worn By DME-Diesel Blends

With increasing number of car and world's attention on environmental protection, the engines confronting with the dual pressure from both keep and increase the existing performance and reduce the emissions. Because the emission ingredients are immediately related to the engine's fuel except the form of combustion process. In order to reduce the emission, the most immediately means we can take is to use the fuel which produces less harmful emission. At the mean time, the human being need a kind of new energy to replace the diesel because the petroleum crisis. So the research based on the alternative fuels in the internal combustion engine field has become the foreland task.Dimethyl Ether (DME) is the most promising ultra-low-emission alternative fuel discovered recently in the world. As a kind of cleanly burning fuel, DME is catching many researchers' attention in recent years. It is showed by research that its cetane value is so high that DME is perfectly suitable to be alternative fuel of diesel engine, and it is hopeful meeting the future stringent emission regulation of diesel engine because of its clean combustion. Burning DME in the diesel engine can solve the problem that petroleum resources is reducing based on the long-term viewpoint, meanwhile, it can meliorate the emission pollution based on the short-terns viewpoint, which develop a realistically feasible approach to solve tow big difficult problems, namely crisis of energy and environmental pollution.Based on the theory and application study of the new clear alternative fuels-DME and the fuel-design thought, this paper presents a new idea which is to blend diesel with DME to increase viscosity of DME against that viscosity of DME is so low that plunger of high pressure oil pump wear early, which is a problem confining application of DME on the conventional dieselengine.In this paper, the construction design and working principle of fuel feeding and feed-back system of high pressure oil pump are introduced. We proceed the high-pressure fuel injection pump's plunger matching parts assembly wear experiment with the DME-diesel blended as the ratio of 7:3 according to some empirical equation. We can simulate the working condition of engine on the high-pressure fuel injection pump testing platform and run the testing platform long time continuous so as to get exact and proper test dates.Through the comprehensive analysis and proper evaluation on the experiment phenomena and test dates, this paper draws a conclusion that the DME-diesel blended fuel can improve the abrasion of plunger matching parts assembly, and that provides scientific basis and reference to the technology modification of the fuel delivery system in the diesel-engine vehicle burning DME.