掺水乳化油对船舶柴油机燃烧和排放的影响

应用AVL-FIRE软件对使用不同掺水量乳化油燃料的船舶柴油机进行了多维数值模拟研究,对比分析了缸内压力、放热率、缸内平均温度、NOX和碳烟排放浓度,并且得到了缸内温度场、NOX和碳烟浓度场。结果表明,计算燃烧缸内压力曲线与试验缸内压力曲线具有较好的一致性,验证了模型的准确性。通过比较可知,掺水乳化油会使滞燃期延长,在燃烧过程中由于水蒸发吸热,降低了燃烧温度,并且发生水煤气反应,有效地减少了污染物排放。仿真结果表明,使用5%~10%掺水乳化油做为燃料,使NOX排放量减小43.9%~67.7%。

Effect of Water Emulsified Diesel on Combustion andEmissions of a Marine Diesel Engine

In order to study the difference of the performance on diesel engine by water emulsified diesel, multi-dimensional numerical simulation research was established by the software AVL FIRE. Based on the model, such as cylinder pressure, rate of heat release, average temperature in cylinder, NOx and SOOT emission concentration were compared when using different water emulsified diesel, meanwhile, we got the cylinder temperature field and the emissions concentration field. The results indicated that the in-cylinder pressure from simulation were consistent with the experiment data. By comparing the water emulsified diesel emissions performance result, it shows when using 5%-10% water emulsified diesel as fuel, SOOT emission can increase by 4.2%-5.5% and NOx emission can reduce by 43.9%-67.7% in the situation of less loss of power and economic performance.