摘要
选择满足国六排放标准的天然气发动机,用全流稀释排放设备采集了发动机常用工况的排放数据并分析了发动机过量空气系数、催化器温度及发动机尾气中CO、NO x等污染物体积浓度对NH 3排放的影响并提出控制NH 3排放的方法。研究结果表明:当发动机过量空气系数大于0.965时,发动机尾气中NH 3的排放随过量空气系数增大而逐渐降低;发动机尾气排放污染物CO对NH 3的排放量影响较大,在一定范围内CO的体积浓度与NH 3的排放量成正相关,但是NO x的体积浓度与NH 3的排放量没有明显的对应关系。另外,三元催化器(three way catalyst,TWC)包裹保温材料后,发动机尾气中NH 3的排放随着催化器温度的升高而降低。在3种控制天然气发动机尾气中NH 3排放的技术中,当前建议选择两级式TWC技术方案对天然气发动机NH 3排放进行控制处理,待逃逸氨催化器(ammonia slip catalyst,ASC)适应天然气发动机发展后,TWC+ASC可以成为良好的排放控制技术方案。
Using a natural gas engine emitted to CNⅥemission standard,the engine's emission data under normal operating conditions were collected by a full-flow dilution system,and the influence of excess air ratio,catalyst temperature,and CO and NOxemission concentrations on NH3 emissions was analyzed.And on this basis,several methods for controlling NH3 emission were proposed.Results show that when the excess air ratio is greater than 0.965,NH3 emission will gradually decrease,while CO emission has a greater impact on NH3 emission,causing NH3 emission to show a positive growth with increased CO concentration within a certain range.However,there is no obvious relationship between NH3 emission and NOxemission.Moreover,when the three-way catalytic(TWC)converter system is wrapped with thermal insulation material,NH3 emission decreases with the increase of catalyst temperature.In view of this,among the 3 kinds of technologies for controlling NH3 emission from natural gas engines,it is currently recommended to use two-stage TWC technology to control the NH3 emissions of natural gas engines.When an applicable ammonia slip catalyst(ASC)can be successfully developed to eliminate NH3 escaped from TWC aftertreatment system,the use of TWC plus ASC will be a preferred solution for the emission control of natural gas engines in the future.
作者
张腾
谭建伟
田茂军
韩文涛
周伟伟
李云强
ZHANG Teng;TAN Jianwei;TIAN Maojun;HAN Wentao;ZHOU Weiwei;LI Yunqiang(Weichai Westport Co.,Ltd.,Weifang 261061,China;School of Mechanical and Vehicular Engineering,Beijing Institute of Technology,Beijing 100081,China;China Automotive Engineering Research Institute Co.,Ltd.,Chongqing 401122,China;Weichai Power Co.,Ltd.,Weifang 261061,China)
出处
《内燃机工程》
EI
CAS
CSCD
北大核心
2021年第1期47-52,59,共7页
Chinese Internal Combustion Engine Engineering
基金
国家重点研发计划项目(2016YFC0204906)。
关键词
氨排放
三元催化器
天然气发动机
控制技术方案
NH 3 emission
three way catalyst(TWC)
natural gas engine
control technical scheme
