201458 Chapter 12 Control System of larmful Emissions n Engine官haut 《Automotive Configuration,》 草大容复动燥有言海放的装 Lattaner De山山wawh Te中a的传 Caaa由。guingtongjlnda.mm @R冷大？ 窗凡冷大复 24 @凡冷司 15 12.1 Harmful Emissioas in Automotive Eegine 汽车发帆的有言掉被物 nea=体名吗程鹤 三 指不海 VIDEO-CO VIDEO-HC VIDEONO 445 545 5 yParsorr Mumrealudon 2z2Emk的报置eaem 出气 1.Camalysiccememet: 王、MOs satadyticoammriea dr✉得厚N0看化前里5 VIDEO-PM 包R冷法？ 45 附清大草汽部单酒 物P冷 应R冷大2014/5/8 1 1/45 同济大学汽车学院 《Automotive Configuration》 Lecturer ： Dr. Li Liguang/Professor Department：School of Automotive Studies, Tongji University Contact： liguang@tongji.edu.cn Lecture Schedule：12-13 2nd Semester Week 1~8 2/45 同济大学汽车学院 Chapter 12 Control System of Harmful Emissions in Engine Exhaust 第六章 发动机有害排放物的控制系统 12.1 Harmful Emissions in Automotive Engine Exhaust 汽车发动机的有害排放物 12.2 Emissions Control Devices in Gasoline Engine 汽油机的排放控制装置 12.3 Other Emissions Control Devices 其他排放物的控制装置 12.4 Emissions Control Devices in Diesel Engine 柴油机的排放控制装置 3/45 同济大学汽车学院 European emission standards for passenger cars ( g/km) 4/45 同济大学汽车学院 §12.1 Harmful Emissions in Automotive Engine 汽车发动机的有害排放物 Exhaust Types of harmful emissions : CO、 HC、 NOX、PM、SOX. (1) CO: Hydrocarbon fuel uncompleted combustion product, it will reduce the ability to absorb and transport oxygen in blood, after being inhaled(人体吸入后). Formation mechanism: (形成机理) Oxygen deficit(缺氧); Low combustion temperature; Short combustion time;  Inhomogeneous mixture(混合不均). Generation rate of CO is mainly influenced by coefficient of excess air (过量空气系数):a 5/45 同济大学汽车学院 The formation of HC in combustion ： lack of oxygen, gap effect（缝隙效应）, chilling and quenching（激冷与淬熄）. Include unburned and incomplete combustion fuel and lubricating oil steam. 包括未燃和未完全燃烧的燃油和润滑油蒸汽。 HC and NOx can form photochemical smog(光化学烟雾) in sunlight, which is harmful to human and environment. (2) HC: HC in exhaust accounts for 60% of the total HC; HC in crankcase leap gas (曲轴箱窜气)accounts for 25% of the total HC; HC in fuel supply system steam(供油系统的HC蒸气) accounts for around 15% ~ 20% of the total HC. Source: 6/45 同济大学汽车学院 (3) NOX： Composition: NO (95%), NO2. High temperature High oxygen concentration Long duration Formation mechanism: NOx and HC can form photochemical smog(光化学烟雾) in sunlight, which is harmful to human and environment. 7/45 同济大学汽车学院 (4) Particulate Matter emissions: the dry soot(碳烟) in diesel engine exhaust + the soluable organic fraction adsorbed on their surface(表面吸附的可融性有机物). Formation mechanism: soot is cracked(裂解) by hydrocarbon fuel under high temperature and oxygen deficit（高温缺氧）. Harm: particles below 0.1 um are the most harmful to human body, after being inhaled into lung ,they will be adsorbed on the lung cells. And soluble organic fraction(可溶性有机物), polycyclic aromatic hydrocarbons(多环芳香烃) are cancer￾causing toxins(致癌物质). 8/45 同济大学汽车学院 (5) SOX： Composition: most of SOX is SO2, the quantity of SO3 is quite little in engine exhaust. SOX come from the sulphur ( 硫) in the fuel(Gasoline or diesel oil) oxidated by oxygen in combustion process. Harm: SOX are harmful to human body.  After being emited into the air ,they will form acid rain(酸雨), moreover, 50% of SOX will become sulfates(硫酸盐) which is part of PM. SOX will poison three-way catalyst(三效催化剂) in aftertreatment system. As emission regulations have become increasingly restrictive, the quality of SOX in the fuel(Gasoline or diesel oil) has been less. 9/45 同济大学汽车学院 §12.2 Emissions Control Devices in Gasoline Engine 汽油机的排放控制装置 1. Catalytic converter(催化转化装置); 2. Devices to reduce HC emissions at low temperature; 3. Lean NOx catalytic conversion device(稀薄NOx催化转化装置); 4. Exhaust Gas Recirculation System(废气再循环系统);