Numerical Calibration Of Injection Parameters For Diesel Engine Electronic Unit Pump

With increasingly stringent emission regulations, people hope diesel engine fuel injection system to achieve high injection pressure, flexible control of fuel injection quantity, variable injection timing, and high injection rate to meet the Euro III and higher emission standards. The electronically-controlled fuel injection system of diesel engine is an effective mean to achieve flexible control of injection progress. Electronic unit pump (EUP) system is more suitable for the electronic transformation of conventional diesel engine because of its small changes to the original machine, strong adaptability, good reliability, stable performance characteristics. It is one of the most widely used in heavy-duty diesel injection systems in Europe currently, and is also very suitable for the application environment of poor oil and road conditions in China.The matching and calibration of the EUP diesel key MAP are mainly relying on the experiment at home and abroad currently. We need to do a large number of tests for the experimental prototype under specific circumstances. This process consumes a lot of cost and time and is difficult to achieve for the extreme working conditions. This paper attempts to calibrate the injection process parameters MAP by the method of one-dimensional numerical simulation of whole diesel engine working process.With ID simulation and analysis method of internal combustion engine working process, the models of diesel engine whole machine and fuel injection system were built up. The calculation was based on the theory of ID non-steady compressible fluid, dynamics theory of the fuel injection system mechanical components and the heat transfer theory. The influence of engine speed to the parameters of the injection process was analyzed. The fuel injection pressure and mass flow rate affected by the structural parameters of the fuel injection system (plunger diameter, length and diameter of the high pressure tubing, nozzle diameter) were studied. Starting from the engine performance, an EUP diesel engine with unknown injection parameters was calibrated by numerical simulation, and the injection MAP based on the optimal compromise of power, fuel economy and emissions performance was obtained. Based on the injection parameters of the conventional working conditions, the influence of environmental temperature, pressure and altitude conditions to diesel engine performance was studied. Performance of diesel engine was more sensitive to environment pressure change, but the temperature change had less impact on the performance of diesel engine. So when we study the environmental adaptability of diesel engine and diesel engine working in a complex environment, we should pay more attention to the impact of atmospheric pressure. Keeping the diesel engine structural parameters constant, the engine performance at low pressure and high altitude was recovered partly by increasing the fuel injection timing angle and reducing the fuel injection quantity.