加热器起燃过程数值模拟及其结构的改进

Numerical Simulation of the Heater Starting Process and the Modification of the Chamber

为了提高加热器的工作性能,对汽车YJQ 32 / 2型加热器启动过程的流动、喷雾和燃烧进行了数值模拟分析。根据模拟结果进行了加热器的改进。试验表明改进后的加热器低温点火能力明显提高,启动过程的碳烟排放水平显著降低。根据数值模拟结果给出了一种改进火焰筒的方案。

Numerical simulations of the flow, spray and combustion in the starting process of the heater have been done. The simulation results indicated that fuel vapor density around the spark plug was thin. It was also found by the simulation that the soot was mainly formed near the inlets where the fuel/air ratio was high. According to the simulation results, the spark plug was moved near to a thick place and small holes were made on the inlets to strengthen the air/fuel mixing near the inlets. The experiments found that the modification of the ignition place improved the cool-start ability and the added small holes reduced the soot emission during the starting process. Based on the temperature field that was gotten from the simulation, a method to improve the durability of the chamber was given.