The Simulation In Working Process And Miller Cycle Of 12V240 Diesel Engine

In recent years, with the growing oil crisis and environmental crisis, the requirements of economy,power and emissions performance on internal combustion engines around the world have become more and more stringent. Traditional internal combustion engine design based on experience and experimental methods can not meet the requirements of today's development of internal combustion engine. The development of computer technology has injected new vitality into the internal combustion engine design and development. Through the computer simulation of internal combustion engine can predict the combustion performance, optimizing internal combustion engine structure, significantly reduce development time and cost.In this paper, through the careful study of the structure of 12V240 diesel engine, we established the 12V240 diesel engine simulation model by using AVL boost software. Through experiments and empirical formula we determined the model parameters required for 12V240 diesel engine in calibrated process simulation work conditions. The simulation results compared with the experimental results, the performance parameters of the data and indicator diagram is very close, less errors, so the model is correct.After the premise of Verifying the accuracy of the original model, we change the engine's compression ratio and fuel injection timing, calculated engine performance at calibration conditions. It can be seen, improve engine compression ratio to an appropriate data can improve engine combustion and the economy. With the injection timing increasing, the power and economy are improved, but the NOX emission deterioration.In order to reduce NOX emissions, on the basis of the original model, the diesel engine cycle simulation used Miller cycle. The results show that by using two-stage or multi-stage booster to ensure that no change in circumstances, by shutting down the intake valve before, we can obtain Miller Cycle in Diesel Engine. Using Miller cycle, can reduce the cylinder combustion temperature at starting of combustion, the maximum combustion temperature of the cylinder, so that we can achieve the purpose of reducing NOX emissions...