Turbocharged Diesel Engine Thermodynamic System Working Process Simulation

Along with the petroleum depletion and increasingly environmental pollution, internal combustion engine development faces severe challenge. Reducing engine fuel consumption and emission is the priority in engine research. Turbocharged diesel engine with intercooler has more output power, better fuel economy and lower emissions; it is widely used as clean and advanced power. Using numerical simulation to predict engine performance and emissions, optimize engine parameters; has great realistic significance. The zero-dimensional and quasi-dimensional models can hardly describe the essence of engine combustion and predict engine emission; multi-dimensional modeling of engine combustion provides a feasible solution of these problems.For the purpose of engine working process simulation, the influence of exhaust gas pressure wave can be ignored, thus the intake and exhaust system parameters is averaged and calculated per cycle. This constant pressure method simulates the practical thermodynamic process of all varieties of turbocharging systems with high efficiency and fast convergence; the calculation results are identical with the results using filling and emptying method. After diesel engine grid with vertical valve, light co combustion chamber is established, multi-dimensional combustion simulation program (KIVA-3V) which issued by Los Alamos National Laboratory is used to model engine working process, and the intake and exhaust system is calculated under constant pressure method. The calculation results are approximately in agreement with the test results. The program can be used in turbo matching and turbocharged diesel engine working process simulation.Based on those works mentioned above, the effects of intake air temperature, injection timing and injection mass on turbocharged diesel engine performance and emissions are investigated. The calculation results show:intercooler improves engine output power at low cost, it's quite flexible for installing; injection delay reduce engine NOx emissions obviously, turbocharged diesel engine has a good load characteristics.