重型柴油机颗粒物分布规律的试验研究  

Experimental study on particle distribution of exhaust emission of heavy-duty diesel engine

作　　者：周小波 胡清华[1] 闫峰[3] 苏万华[2] Zhou Xiaobo;Hu Qinghua;Yan Feng;Su Wanhua(School of Computer Science and Technology,Tianjin University,Tianjin 300350,China;State Key Laboratory of Engines,Tianjin University,Tianjin 300072,China;China Automotive Technology ＆ Research Center Co.,Ltd,,Tianjin 300300,China)

机构地区：[1]天津大学计算机科学与技术学院,天津300350 [2]天津大学内燃机燃烧学国家重点实验室,天津300072 [3]中国汽车技术研究中心有限公司,天津300300

出　　处：《农业工程学报》2018年第13期62-69,319,共9页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家高技术研究发展计划(863计划)"基于柴油机均质压燃发动机关键技术攻关及样机研制"(2012AA111714);国家自然科学基金重点项目"直喷式内燃机燃烧过程和功转化率最大化的研究"(51236005)

摘　　要：为了同时控制车用重型柴油机的颗粒物排放质量和数目,该文对稳态工况及瞬态工况下柴油机排放颗粒物分布规律进行了试验研究。试验结果表明:在稳态工况下,随着负荷的增加或者转速的提高,积聚态及核态颗粒物数目浓度、中位直径(count median diameter,CMD)、表面积和质量均呈现增大趋势,且峰值向大粒径方向偏移。在本研究中,稳态工况全工况总颗粒物数目浓度为1.5×10~6~4.5×10~6个/cm^3,积聚态颗粒物数目浓度为2×10~6~1×10~7个/cm^3,而核态颗粒物数目浓度为1×10~7~3×10~7个/cm^3,在总颗粒物数目浓度中占比为65%~96%。全工况当量比均小于0.7,在中低转速,当量比对颗粒物分布影响较为明显,在高转速尤其是大负荷条件下,当量比的影响减弱。在瞬态工况下,颗粒物数目浓度出现了与颗粒物质量类似的排放尖峰现象,浓度峰值达到2×108~7×108个/cm^3,比其对应的稳态工况出现的浓度峰值高出1个数量级。而且排放尖峰现象中,积聚态颗粒物数目浓度占主要部分,其峰值浓度比稳态工况要高出2个数量级,此时排放尖峰现象中核态颗粒物数目浓度也出现明显增长。排放尖峰现象对应的粒径主要集中在积聚态颗粒物的50~200 nm范围和核态颗粒物的6~8 nm及20~50 nm范围。这主要是因为当量比在瞬态过程出现了超过临界当量比0.8的情况。研究结果对重型柴油机颗粒物排放控制以及生成机理有重要指导意义,并可为排放后处理器的匹配计算提供数据支持。In recent years, smog has emerged in most of major cities in China. Epidemiological and toxicological studies showed that the ultrafine particles in the atmosphere adhere to a large number of toxic substances, which can cause serious harm to human respiratory and cardiovascular and other organs after they enter the human body through the respiratory tract. and the data indicated that it had a significant correlation with human morbidity and mortality. Particulate emissions from diesel engines are an important source of ultrafine particles in urban atmosphere. The researchers found that the weighing method of particulate matter detection cannot accurately reflect the emission levels of internal combustion engines. This new method for measuring the number of particulate matter emissions after removing volatile matter from the method has been widely recognized and included in the scope of regulatory investigation. However, there are few studies on the number and size distribution of particles in the transient process of diesel engine. In order to simultaneously control the quality and quantity of particulate matter emitted from heavy duty diesel engines, the particle distribution of exhaust particulates from diesel engines under steady and transient conditions was studied. The test bench is a 12 L heavy duty diesel engine and an electric dynamometer. The test bench is a prototype with no post-processor and meets the Euro IV regulations. It has been certified by China Automotive Technology Research Center（CATRC）. The engine intake system consists of a two-stage turbocharging system with variable geometry section turbine（VGT）, a high-pressure EGR system and an intake valve late closing system（IVCT system, which is developed by the research group independently）. Cambustion DMS500 fast particle spectrometer was used to analyze the particle size distribution of diesel engine under transient conditions. The experimental results showed that, in the steady state, with the increase of load or speed, the concentra

关 键 词：柴油机 排气 颗粒 稳态工况 瞬态工况 分布规律 核态和积聚态颗粒 

分 类 号：TK421.5[动力工程及工程热物理—动力机械及工程]