Modeling And Simulation On Fuel Injection System Of AD Type Pump By Computer

With paying more and more attention to environment protection and energy consumed in the world, an even higher demand is proposed to the performance of diesel engine in order to reduce exhaust emissions and cut down the consumption of raw materials. The injection quality of the performance of the fuel injection system is very important for diesel engine. The research on modeling and analysis of a fuel injection system of AD type pump are discussed in this dissertation.The subject discussed in this dissertation is related to a collaboration project between Dalian University of Technology and Dalian Fuel Injection Equipment Factory, which is financially supported by Factory. The AD type pump injection system is a typical one in fuel injection systems, and has quite popular applications. Modeling on injection system of AD type pump is very important in research and practice. To build the model of fuel injection system, the traditional approach is first implementing a great deal of fundamental experiments, collecting the experimental data, then analyzing and doing more supplementary experiments recursively to get a reasonable model. The traditional approach is expensive and high time consumed. A new approach for building the model of fuel injection system of AD type pump is proposed in this dissertation, which consists of two stages. Based on overview and analysis of the research results on fuel injection system published in science literatures, a reasonable prototype theoretical model can be established in the first stage. During the second stage, some key modified coefficients are added to the prototype theoretical model, and some typical working data are required. After that a following optimization procedure is done to get the refined values of the modified coefficients, which will let the simulation data based on computation model coincide with the experimental data. Research on modeling on fuel injection system of AD type pump includes three aspects as follows:1. Based on fuel injection system working principle and its studies, a working modeling for AD type pump is established.2. Numerical computation methods for fuel injection system of AD type pump are developed in the dissertation. With the use of the prototype model for AD type pump directly, there are some deviations between simulation data and experimental data. A working model of fuel injection system of AD type pump is established. The modified discharge coefficient, pressure coefficient and resistance coefficient of the working model have been accomplished by optimization. These modified coefficients have different calculating results when the conditions change. Based on the optimum results of these parameters, the modified coefficients equations are set up by regression, and the working model of AD type pump is accomplished. The theoretical research based on the proposed methods can not only reduce some experiments, but also reveal the influence of the variations of the system parameters on fuel injection characteristics.3. The Object-Oriented technology is used in the work. The software is developed for fuel injection system of AD type pump.In addition, the performance of speed regulator is discussed and its modeling by computer is described. That the profile of the cam which drives the plunger motion determines the fuel feed system directly is also discussed.The software has been used by Dalian Fuel Injection Equipment Factory and more suitable for designers.The research result can be expansively applied to other related area, such as some other traditional fuel injection systems (for example P7 type pump) and electronic position controlled fuel injection systems.