| 摘要:为了快速且准确地预测直喷柴油机的放热及排放情况，提出了直喷柴油机燃烧的现象学快速预测模型。该模型基于气相射流喷雾模型，将柴油机的燃烧过程分为预混燃烧、喷射中的扩散燃烧及喷射后的扩散燃烧三个阶段进行燃烧计算，并将喷雾区域分为已燃区和未燃区进行排放计算。该模型相较于多区模型，简化了分区，考虑了喷油产生湍动能的影响。在额定转速下，基于90%负荷标定的模型预测结果和潍柴WP7柴油机其它负荷的试验结果相比，最高燃烧压力和平均压力误差均小于5%；中高负荷的放热率趋势基本相同，10%累计放热对应的曲轴转角误差小于0.6 ℃A，90%累计放热时对应的曲轴转角误差小于5℃A；高负荷的排放预测误差在5%左右；且各工况计算可在数秒内完成。表明:所提出的模型能快速且较准确地预测直喷柴油机中高负荷工况下的燃烧情况。 |
| 关键词: 现象学燃烧模型 燃烧 排放 试验 |
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| A Phenomenological Fast Prediction Combustion Model forDirect Injection Diesel Engine |
| Meng Wei,Deng Kangyao |
| Key Laboratory for Power Machinery & Engineering of Ministry of Education, Shanghai Jiao Tong University,Shanghai 200240;Collaborative Innovation Center for Advanced Ship and Deep-Sea Exploration，Shanghai 200240 |
| Abstract:In order to predict the heat release and emission for direct injection diesel engine quickly and precisely, a phenomenological fast prediction combustion model for direct injection diesel engine was proposed. The model is based on a gas phase jet spray model, and divides the diesel combustion process into three steps including premixed combustion, diffusion combustion during injection and diffusion combustion after injection to calculate the combustion, and calculates the emission by dividing the spray zone to burned zone and unburned zone. Comparing to multi-zone combustion model, the model simplifies partition and considers the influence of turbulence energy from injection. In rated speed, comparing the results of prediction calibrated by 90% load working condition with the experiment results of Weichai WP7 diesel engine on other loads, the errors of both detonation pressure and mean pressure are less than 5%, the tendency of heat release rate on medium and high load is basically the same, the error of CA10 is less than 0.6 °CA, the error of CA90 is less than 5 °CA, the error of emission prediction on high load is about 5%, the computation can be completed within several seconds. As the results show, the phenomenological combustion model can predict the combustion in direct injection diesel engine on medium and high load rapidly and exactly. |
| Key words: phenomenological combustion model combustion emission experiment |
