柴油/甲醇组合燃烧尾气中甲醛排放特性研究  

Formaldehyde Emission Characteristic from Diesel/Methanol Compound Combustion Engine

作　　者：姚春德[1] 彭红梅[1] 刘义亭[1] 李帅[1] 

机构地区：[1]天津大学内燃机燃烧学国家重点实验室,天津300072

出　　处：《内燃机学报》2008年第3期233-237,共5页Transactions of Csice

基　　金：国家自然科学基金资助项目(50576064)

摘　　要：在一台经过改装的压燃式组合燃烧发动机上,采用柴油/甲醇组合燃烧(DMCC)模式进行了台架试验,利用气相色谱分析技术检测了发动机在1800 r/min时尾气中甲醛的排放特性,研究了不同负荷、不同喷醇量对尾气中甲醛排放量的影响,同时研究了催化转化器对甲醛的转化效果。试验结果表明:在压燃式发动机上采用DMCC模式,低负荷运行时,尾气中甲醛含量随喷醇量的增大而增加,在甲醇对柴油的替代率为45%时,甲醛排放量达到170×10-6(体积分数);在中、高负荷运行时,甲醛排放量随喷醇量的变化趋势不是特别明显,在90×10-6以内。催化转化器对甲醛的转化效率与排气温度关系密切,当排气温度在290℃以下时,催化转化器可以有效降低甲醛排放量;当温度高于300℃时,催化后尾气中的甲醛排放量反而增加。The bench experiments were conducted on a diesel/methanol compound combustion engine. Gas chromatography analyzing approach was used to measure the formaldehyde emission from the DMCC engine at engine speed of 1 800 r/min. The influences of load, methanol and oxidation converter on the formaldehyde emission characteristics were investigated. The results show that engine-out formaldehyde emission increases with the increasing of methanol at the low load, but little variation at the middle load and the high load. The conversion efficiency of oxidation converter is closely related to the exhaust temperature. Engine-out formaldehyde emission with an oxidation converter gets decreasing at exhaust temperature below 290 ℃, and it shows an increasing at exhaust temperature over 300℃.

关 键 词：发动机 柴油/甲醇组合燃烧 甲醛 气相色谱 

分 类 号：TK411.5[动力工程及工程热物理—动力机械及工程]