满足国五排放标准的柴油甲醇双燃料发动机非常规排放研究

在一台装备有电控单体泵增压中冷系统柴油机的进气管上,加装甲醇喷射装置并向进气道喷入定量的纯甲醇,结合废气再循环(EGR)技术并使用氧化催化转化器(DOC)组合微粒氧化催化器(POC)后处理系统,使其常规排放能满足国五排放法规基础上,全面研究了柴油甲醇双燃料(Diesel Methanol Dual Fuel,DMDF)发动机的非常规排放特性.在采用国五排放法规标准规定的ESC(稳态13点工况)测试方法条件下,利用FTIR(傅里叶变换红外检测法)对DMDF发动机的检测结果表明:该机非常规排放物主要为甲醇、甲醛、1,3-丁二烯、苯、甲苯和SO2,非常规排放物的全工况加权比排放为19.532 g·kW~(-1)·h~(-1),其中,甲醇的全工况加权比排放为11.395 g·kW~(-1)·h~(-1),甲醛的全工况加权比排放为5.927g·kW~(-1)·h~(-1),SO2的全工况加权比排放为0.053 g·kW~(-1)·h~(-1),其余排放物为痕量水平.在催化氧化装置处理后非常规排放物全工况加权比排放为0.115 g·kW~(-1)·h~(-1),降幅为99.41%.催化氧化装置对甲醇、1,3-丁二烯、苯和甲苯的消除率为100%,对甲醛的消除率为99.04%.

Unregulated emissions from DMDF engines to meet with National V emission legislation

The effects of diesel methanol dual fuel (DMDF) engine equipped with turbo-charged, 4-cylinder, electronic unit pump to meet the requirement of National V emission legislation, on unregulated emissions were studied. The DMDF engine employed the system of EGR and diesel oxidation catalyst (DOC) combined with particulate oxidation catalyst (POC). The results showed that the unregulated emissions from the DMDF engine were mainly methanol, formaldehyde, 1,3-butadiene, benzene, toluene and sulfur dioxide in the whole working condition. Among them methanol was 11.395 g·kW^-1·h^-1, and the emission of formaldehyde is 5.927 g·kW^-1·h^-1 respectively, the emission of sulfur dioxide is 0.053 g·kW^-1·h^-1. The total unregulated exhaust emissions from DMDF engine before aftertreatment DOC+POC in the whole working condition was 19.532 g·kW^-1·h^-1, after the aftertreatment the emissions was droped to 0.115 g·kW^-1·h^-1, and the rate of decrease was 99.41%. The efficiency for methanol, 1,3-butadiene, benzene and toluene by DOC+POC was reached 100%, and the efficiency for formaldehyde was 99.04%. Meanwhile, NO_x and PM emissions from the DMDF engine could meet the requirements by National V emission legislation without necessary help of urea as reduction.