Application Of CHEMKIN Software In Numerical Simulation Of Homogeneous Charge Compression Ignition And Fuel Modification

Homogeneous Charge Compression Ignition (HCCI) has the potential of high efficiency and low emission. Now, it has been become one of the front study issues in interal combustion engine. Numerical simulation is also a focus as an effective tool in the study of HCCI combustion.The chemical dynamic process of ethanol is investigated by CHEMKIN in this paper. The simulation of ethanol HCCI engine combustion process and the analysis of the boundary conditions in the process of were done. According to the concept of, a model to simulate HCCI with fuel'modification has been set up. The model has been linked with the original HCCI model. The analysis about the modification chamber parameters affecting on the fuel modification was done.The result shows that HCCI is affected by the intake temperature largely. The higher temperature is propitious to trigger HCCI. Rotation speed influences on the peak value of pressure a little. The autoignition timing is ahead with the increase of speed. The brake mean effective pressure has maximum value when the speed is between 1200 and 1400 r/min. The higher the rotation speed is, the more CO is, and the less NOx is. In the condition of low rotation speed, the case is reversed. When the excess air ratio of mixtures is 3 to 4, the combustion is better.By using the parameters simulation, the range of ethanol HCCI is obtained according to the speed and intake temperature. The range is bounded by knock, misfire, partial combustion. The range of intake temperature is 400 to 500 K, and the range of rotation speed is 800 to 2200 r/min.The effect of fuel modification is affected by the volume of chamber, the phase of exhaust and the phase of entering. The fuel modification achieves the goal.