Experimental Investigation On Seal & Lubrication In High Pressure Pump Of DME Engine

It worries the whole world at the time that the limitless requirement of energy is in conflict with environmental pollution resulting from utilizing endlessly energy sources by human. In order to deal with the problem about energy crisis and the emissions of engine, the research based on the alternative fuels in the internal combustion engine field has become the foreland task. It is confronting with the dual pressure from both the automotive requirement of energy and environmental protection along with the rapid national economic development and the high-speed increase in cars.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 catchingmany researchers' attentions in recent year. 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 tosolve tow big difficult problems, namely crisis of energy andenvironmental pollution.Based on the theory and application study of the new clear alternative fuels-DME, this paper presents a new forcible lubrication system of high pressure oil pump against that viscosity of DME is so low that plunger of high pressure oil pump abrade early, which is a problem confining DME' application in the conventional diesel engine. This system improves and optimizes the construction of the plunger of the high pressure oil pump. Having some definitive pressure' lubrication is applied in the plunger to solving abrasion and leakage while the plunger piston use in the DME engine.In this paper, the construction design and working principle of forcible lubrication system of high pressure oil pump areintroduced as well as the design of simulator stand and the experimental results. Using three fuels such as pure DME, D80and diesel, we do experiments to different plunger pistons at the time ratio according to the working principle. The rule of the simulator stand is to simulate working condition of the high pressure oil pump in the engine, so we can long test continually and 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 forcible lubrication system of high pressure oil pump in the DME engine can improve the abrasion of plunger and decrease DME excessive leakage in the working process, and that provides scientific basis and reference to the technology modification of the fuel delivery system in the diesel-engine vehicle burning DME.