船用柴油机燃用生物柴油排放与消烟机理

Experimental study on the emission reduction mechanism of biodiesel used in marine diesel engine

为研究普通柴油掺混生物柴油后对船用柴油机排放特性的影响,将餐饮废油制生物柴油与普通柴油以10∶90体积比混合。结合船用柴油机台架试验与排放物测试分析,探究燃用小比例生物柴油混合燃料后,船用柴油机气态污染物与颗粒物质的排放特性,以此阐明生物柴油排放相关性变化与消烟机理。试验结果表明:掺混生物柴油后,由于生物柴油高的含氧量,气态排放物中一氧化碳(CO)、二氧化碳(CO_2)、碳氢化合物(THC)均有所下降,可有效改善柴油机有害气体的排放。同时,生物柴油中较少的芳香烃含量可减少燃烧产物中芳烃前驱物,从而抑制颗粒的形成,减少颗粒物质(PM)排放及降低颗粒物质数量(PN)。但过快的燃烧速率会减小火焰的辐射损耗同时提高缸内温度,因此促进了NO_x的生成。为促进餐厨废弃油污治理和交通运输行业节能减排提供参考。

To study changes in emission characteristics for a marine diesel engine fueled with biodiesel blending,this work set up an experiment of marine diesel engine bench with the mixed ratio of diesel to biodiesel fuel of 10:90.The emission characteristics of gaseous pollutants and particulate matter from the engine were evaluated by the combined bench test and emission analysis,and the smoke reduction mechanism of the biodiesel was determined.The levels of carbon monoxide(CO),carbon dioxide(CO2),and hydrocarbon(HC)in the gaseous emissions decrease due to the high oxygen content of the biodiesel,indicating that harmful gas emission could be reduced when blending biodiesel.The low aromatic hydrocarbon content in the biodiesel reduces the generation of polycyclic aromatic hydrocarbon(PAH)in combustion products,thereby inhibiting particle formation and reducing particulate matter(PM)emissions and particle number(PN).The excessively fast burning rate reduces the radiation loss of the flame while increasing the temperature in the cylinder,thereby promoting NOxgeneration.This Promotes the control of waste cooking oil and provides a reference of energy saving and emission reduction in the transportation industry.