Simulation Research On Performance Of Diesel Engine High Pressure Common Rail Fuel Injection

Vehicle emissions cause big pollution on the global living environment, diesel engine is becoming the main power source of future automotive development with its economy, power performance and service life. As the heart of the diesel engine, fuel supply system has an important influence on diesel engine performance. Compared with the traditional oil supply system, electronically controlled High Pressure Common Rail Fuel Injection System has the advantage of high injection pressure, flexible injection. It can not only improve the power performance of diesel engine, but also reduce the energy consumption and exhaust emissions. The research on high pressure injection, high injection rate and more precise and flexible electronic control system is an important direction. This paper is based on the High Pressure Common Rail Fuel Injection System of a diesel engine, take the geometry of several key parameters in the system as the research object, the main research content includes:1. High Pressure Common Rail Fuel Injection System theory research and simulation modeling. Based on navier-stokes conservation equation and the basic theory of fuel injection, established the mathematical model for the mathematical model of the oil pump, injector and common rail tube continuous equation; According to the mathematical model and the actual composition of common rail system, puts forward some basic assumptions, build the system simulation model in GT-Fuel, which is a special simulation platform for fuel injection;2. High Pressure Common Rail Fuel Injection System test validation and simulation research. Test the reliability of the simulation model; adopt Control Variable Method to studies how the common rail pipe diameter, plunger diameter, high pressure tubing length etc, effect the injection performance and common rail pressure of the system;3. High Pressure Common Rail Fuel Injection System structure optimization research. Using experimental design and data processing method, first select the key impact structure, and use the Latin hypercube experimental design to further refine the structure size analysis; On this basis, define improving the injection pressure, reducing rail pressure fluctuation as the objective function, use the Pareto Genetic Algorithm to optimize the system;Based the above theory and simulation research, put forward a new type of common rail pipe structure, the structure can effectively reduce the rail pressure fluctuations and improve the stabability of the injection performance.