【作者】 霍少峰；

【导师】 宋崇林；

【作者基本信息】 天津大学 ， 动力机械及工程， 2010， 硕士

【摘要】 柴油机氧化催化器(Diesel Oxidation Catalyst,DOC)和颗粒物氧化催化器(Particulate Oxidation Catalyst,POC)组合是柴油机满足欧Ⅳ排放标准的重要后处理技术方案之一,目前已在国内外部分柴油机产品中得到应用。为了该技术进一步的推广应用提供理论数据,本文以高压共轨车用柴油机为基础,选取五种不同后处理器组合,结合HORIBA气体分析仪和AVL部分流采集系统,运用气相色谱—质谱联用技术(GC-MS),开展了不同特性的DOC和POC对柴油机常规污染物、非常规污染物影响规律的研究。研究结果表明:1.在稳态循环(ESC)和瞬态循环(ETC)下,发动机加装DOC+POC组合后,CO比排放量最大降低幅度分别为98%和97.1%,HC比排放量最大降低幅度分别为95.8%和94.2%,PM比排放量最大降低幅度分别为60.4%和65%,NOx比排放量降低幅度较小,均低于10%,整机达到国Ⅳ排放标准。2.在稳态工况下,发动机加装DOC+POC组合后,甲醛、乙醛和一氧化氮比排放量均明显降低。DOC催化活性越强,空速越低,DOC+POC组合对甲醛、乙醛和一氧化氮催化氧化效果就越好,最大降低幅度分别为82%、98%和62%。加装DOC+POC组合后,二氧化硫排放量也有不同程度的降低,DOC催化活性越强,空速越低,二氧化硫比排放量降低幅度就越大,DOC+POC组合抗硫能力就越差。3.发动机加装DOC+POC组合后,微粒中的可溶性有机物(SOF)及总多环芳香烃(PAHs)比排放量均明显降低。在ESC和ETC试验下,SOF最大降低幅度分别为75%和40%。DOC和POC的催化活性越强,空速越低,DOC+POC组合对总PAHs的催化氧化效果就越好,ESC和ETC试验下最大降低幅度分别为28%和55%。4.发动机加装DOC+POC组合后,2环、3环和4环芳香烃比排放量均降低,其中4环芳香烃降低幅度最大。DOC和POC的催化活性越强,空速越低,DOC+POC组合对4环芳香烃的催化氧化效果最好,ESC和ETC试验下,4环芳香烃最大降低幅度分别为61%和81%。更多还原

【Abstract】 As an important aftertreatment way to meet Euro IV standard emissions regulation, diesel oxidation catalyst (DOC) and particulate oxidation catalyst (POC) have presently been applied on several diesel engines in the world. To provide fundamental database for the further acceptance, tests for five different DOC and/or POC aftertreatments were conducted on a common–rail heavy-duty diesel engine, coupled with AVL partial flow dilution channel system and Horibar exhaust gas analyzer. Meanwhile, the polycyclic aromatic hydrocarbons (PAHs) in soluble organic fraction (SOF) were measured by gas chromatography-mass spectrometry (GC-MS). The effects of DOC and/or POC on the regulated emissions and unregulated emissions were investigated and the main research conclusions of this dissertation are as follows:1. At the European steady state cycle (ESC), the presence of DOC+POC on the diesel engine led to a maximum decrease of 98% in the brake specific emission of carbon monoxide (CO), 97.1% in the brake specific emission of hydrocarbon (HC) and 60.4% in the brake specific emission of particulate matter (PM), respectively. However, a slightly change was observed for the brake specific emission of nitrogen oxides (NOx), with a less than 10% reduction. At the European transient cycle (ETC), the application of DOC+POC on the diesel engine resulted in a maximum decrease of 97.1% in the brake specific emission of CO, 94.2% in the brake specific emission of HC and 65% in the brake specific emission of PM, respectively. However, a slightly change was also observed for the brake specific emission of NOx, with a less than 10% reduction.The engine dynometer test result showed that the diesel engine with DOC+POC could meet the Chinese phaseⅣemissions regulation.2. Under steady operating conditions, the brake specific emissions of formaldehyde, acetaldehyde and nitric oxide (NO) showed obvious decreases when the DOC+POC were used. The higher the catalytic activity of DOC and the lower air speed were, the more noticeable reductions for formaldehyde, acetaldehyde and NO were obtained. The maximum decreases were 82% for formaldehyde, 98% for acetaldehyde and 62% for NO, respectively. The brake specific emission of sulfur dioxide (SO2) also gave a decrease when the DOC+POC were used. The lower brake specific emission of SO2 and resistance of DOC+POC to sulfide were attained in the case of the higher catalytic activity of DOC and the lower air speed.3. With DOC+POC on the diesel engine, the brake specific emissions of PAHs and SOF presented pronounced decreases.Under the ESC and ETC conditions, the maximum decreases of SOF were 75% and 40%, respectively. The higher catalytic activity of DOC and POC and the lower air speed resulted in a more effective oxidation of PAHs. The maximum decreases of PAHs were 28% for the ESC and 55% for ETC, respectively.4. The brake specific emissions of 2, 3 and 4 aromatic rings in PAHs showed noticeable decreases with DOC+POC on the diesel engine, where the decrease for 4-ring PAHs was the most significant. The higher the catalytic activity of DOC and POC and the lower the air speed, the more effective the oxidation of 4-ring PAHs. Under the ESC and ETC conditions, the maximum reductions of 4-ring PAHs were 61% and 81%, respectively.更多还原