掺氢燃烧和天然气替代率对柴油机的影响

Effects of mixed hydrogen combustion and natural gas substitution rate on diesel engines

为促进新型替代燃料的应用,缓解日益严重的能源危机和环境污染情况,以TBD620单缸柴油机为研究对象构建仿真模型,通过模拟研究天然气替代率对柴油机燃烧及排放性能的影响。柴油机在额定工况时,设置天然气替代率为0%~90%进行仿真计算。随后,在天然气替代率为90%时,设置氢气掺混比为10%~90%做进一步优化。结果表明,天然气替代率为70%时柴油机性能较好,替代率为90%时性能较差。在天然气替代率为90%,随着掺氢比的增加,缸压峰值及最大燃烧温度都在增加。CH_(2)O、CO、CO_(2)、SOOT的最终排放量降低,NO_(x)的最终排放量升高,柴油机的性能得到了改善。综合分析,在天然气替代率为90%时,选取掺氢比为50%的方案较为合适。

To promote the application of new alternative fuels and alleviate the increasingly serious energy crisis and environmental pollution,a TBD620 single-cylinder diesel engine was taken as the research object,and a simulation model was constructed to study the effect of natural gas substitution rate on the combustion and emission performance of diesel en-gines.When the diesel engine is in the rated working condition,the natural gas replacement rate is set to 0%-90%for simula-tion calculation.Subsequently,when the natural gas replacement rate is 90%,the hydrogen mixing ratio is set to 10%-90%for further optimization.The results show that the diesel engine performance is better when the natural gas replacement rate is 70%,and the performance is poor when the natural gas replacement rate is 90%.When the natural gas replacement rate is 90%,with the increase of the hydrogen mixing ratio,the peak cylinder pressure and the maximum combustion temperature all increase.The final emissions of CH_(2)O,CO,CO_(2),SOOT are reduced,the final NO_(x)emissions are increased,and the per-formance of the diesel engine is improved.Comprehensive analysis shows that when the natural gas replacement rate is 90%,it is more appropriate to select the scheme with a hydrogen mixing ratio of 50%.