A Study On Simulation And Control Fuel Injection System For Dimethyl Ether

DME is the one of the ramifications of methanol, it is also an important intermediate of carbon chemistry industry, and applying very widely. Experiments in domestic and abroad showed that its emission could easy to reach Europe III emission criterion without catalyzing disposal. Therefore, the experts in domestic and abroad believed that using DME not only was economization and protecting the natural environment, it also had strategic significance. However, the bulk modulus of elasticity is too small for DME, and it is gaseity in normal temperature and pressure Although there were some problems to be solved if we wanted to apply the DME on diesel engine. All the problems summed up were how to choose injection system, considering the merits of the DME as well as how to modulate construct parameters of the system to adapt to the fuel.At the same time, structure of EUP was simplified, and it was flexible to control the fuel injected and injection timing while fluctuation of timing was improved consequently. All these merits were helpful for the application of DME on diesel engine. Associating combustion characteristic and the project of devise injection system, this study combined simulation technical and pump test bench .Reforming advices and controlling strategies in general were also put forward on researching results.At first, the physical and chemical merits of DME were introduced and research actuality in domestic and abroad of DME as a substitute fuel. Then analyzing the development of diesel injection system in domestic and abroad. According to deeply research the characteristic of DME, and putting up simulation of DME injection system, we established a useful control strategy to ECU, and applying to the DME engine. It could make precise control of DME engine come true. It also supplied the possibility of improve combustion and emission after DME substitute diesel. Do the further researches, we could make hardware according to the simulation. Using the software of AMEsim4.30 to built electronic unit pump model, and established a useful control strategy in ECU, it was easy to get kinds of result of different working condition. The simulation results showed that applied DME to electronic unit pump injection system, and decreased needle open pressure were caused higher pressure wave in injection chamber, because the bulk modulus of elasticity is too small for DME and it was compressible. With the increased of plunger diameter, the maximum pump pressure and injection pressure were also increased. Changing main injection PWM wasn't caused pressure fluctuation. However, changing pre-injection PWM and interval PWM were make two pressure waves superpose, and it also caused needle move. We need considerate the phase problem of two pressure wave when they were superposed. Therefore, improving the injection capability need change the key parameters of DME injection system of electronic unit pump.Furthermore, according to the research of DME in domestic and abroad, we built an experiment rig and wrote down the experiment data of pump and injection chamber pressure wave. Then compared the experiment data with simulation result, we devised the way of pump experiment of EUP and carried out the initialize demarcation.At last, we drew a conclusion that improved some key parameters of electronic unit pump and established a useful control strategy in ECU, it made the possibility of DME applied to EUP come true.