1、同济大学 硕士学位论文 摘要I硕士学位论文（专业学位）柴油机高原冷机起动排放特性研究姓 名：学 号：所在院系：汽车学院职业类型：工程专业领域：动力工程指导教师： 年 月同济大学 硕士学位论文 柴油机高原冷机起动排放特性研究II摘要柴油机由于其可靠性好、热效率高、燃油经济性好等特点，广泛应用于工业、运输、农业等领域。起动阶段排放是柴油机排放控制的重点，目前针对柴油机平原环境起动排放的研究很多。我国高原地区约占国土面积的三分之一，具有面积大、分布广的特点，进行柴油高原起动排放研究，采取措施控制柴油机高原排放，具有重要的学术意义和参考价值。本文以某型电控直列泵六缸柴油机为研究对象，进行了 0m450
2、0m 海拔的冷机起动排放试验，分析了海拔高度、冷却液温度、供油策略对柴油机起动排放的影响。在试验研究的基础上，采用 CHEMKIN-PRO 软件，利用正交设计法，对该柴油机 3000m 和 4500m 海拔水平下的起动排放进行了仿真计算，得到了该柴油机的低起动排放最优控制参数组合。主要结果如下：1) 试验研究了海拔高度、冷却液温度、供油策略对柴油机起动气态污染物排放的影响。结果表明：海拔升高导致柴油机起动时间增长，燃烧温度降低，CO 和 HC 瞬态排放浓度升高，NO X 浓度降低，导致 CO 和 HC 排放显著增加，NOX 排放降低。海拔每升高 1000m，CO 排放增加 24.4%，HC 排
3、放增加40.0%；冷却液温度升高，缸内燃烧热氛围变好，起动时间缩短，CO 和 HC 排放降低，NO X 升高，冷却液温度 60时该机起动产生的 CO、HC 和 NOX 分别为 11.6g、2.9g 和 0.43g；与原策略（A 策略）比较，高原起动时， 500r/min 以下低转速减油策略（B 策略） 、500r/min 以下低转速和 800r/min 以上高转速减油策略（C 策略） 、0r/min800r/min 全过程减油策略（D 策略）的起动时间缩短，CO 和 HC 排放降低。2) 试验研究了海拔高度、冷却液温度和供油策略对柴油机起动颗粒物排放的影响。结果表明：海拔升高，起动时间增长，虽
4、然核态颗粒和聚集态颗粒数浓度减少，但颗粒物总质量排放增加，颗粒平均几何粒径增大。冷却液温度升高，核态颗粒浓度增加，聚集态颗粒浓度降低，颗粒总质量排放降低，颗粒平均几何粒径减少。与原策略（A 策略）比较，减油策略（ B、D 策略）的核态颗粒浓度减小，聚集态颗粒浓度增加，颗粒总质量排放增加，颗粒平均几何粒径增大；减油策略（C 策略）的核态颗粒浓度增加，聚集态颗粒浓度减小，颗粒总质量排放减小，颗粒平均几何粒径降低，3000m 和 4500m 海拔，500r/min800r/min 中转速减油（C 策略）的颗粒物排放最低。3) 建立了该机起动排放仿真模型，仿真分析压缩比对该机起动排放的影响。以压缩比、
5、冷却温度、供油策略为控制因素，以降低排放为目标，设计了正交同济大学 硕士学位论文 摘要III方案，仿真分析了该机 3000m 和 4500m 海拔高度的起动排放。结果表明：3000m 海拔，60冷却液温度、压缩比 15.0、中高转速减油策略的 CO、HC 和苯化物（颗粒前驱物）排放最低，比优化前分别降低 58.5%、36.0%和21.1%； 4500m 海拔，60冷却液温度、压缩比 15.0、全过程减油策略的CO、HC 和苯化物排放最低，比优化前分别降低 57.5%、22.1%和 44.7%。关键词：柴油机，高原冷机起动，排放，研究 同济大学 硕士学位论文 柴油机高原冷机起动排放特性研究IVA
6、BSTRACTWith its characters, such as high reliability, high thermal efficiency, good fuel economy and so on, diesel engines are now widely used in areas of industry, transportation, agriculture, etc. Cold start emission is one of the most important diesel engine emission control aspects, and there ar
7、e many researches on start emission of diesel engine in plain over the world. Plateaus in our country have the characteristics of large and widely distributed, and the total area of plateau is about a third of the land area of our country. Studying start emission of diesel engine and adopting measur
8、es to control diesel engine emission at high altitude have important academical significance and reference value.A six cylinder heavy duty diesel engine with electric controlled mechanical-line pump was employed in diesel engine cold start emission experimental research at the altitude of 0m4500m. t
9、hen, impacts of different altitudes, coolant temperature and fuel injection strategies to diesel engine cold start emissions were analyzed. According to the results of experiment, cold start emission of diesel engine at the altitudes of 3000m and 4500m was calculated on CHEMKIN-PRO with the orthogon
10、al design method, and got the optimized level assemblies of engine start control factors. Main contents and conclusions are as follows:Firstly, impacts of different altitudes, coolant temperature and fuel injection strategies to gaseous emissions of diesel engine cold start have been studied. The re
11、sults showed that increased altitude resulted in longer start time, lower combustion temperature, increasing concentration emission of CO and HC, and decreasing concentration emission of NOX. Increased altitude led to increasing mass emission of CO and HC, and decreasing mass emission of NOX. Every
12、1000m the altitude increased, mass of CO and HC increased by an average of 24.2% and 40.0%. Increased coolant temperature resulted in better thermal atmosphere in chamber, shorter start time, and lower mass emission of CO and HC, but higher mass emission of NOX. the mass emission of CO, HC and NOX w
13、ith the coolant temperature 60 were 11.6g, 2.9g and 0.43g. At high altitude, compared with strategy A, strategy B with smaller fuel injection mass below the engine speed of 500r/min, strategy C with smaller fuel injection mass below the engine speed of 500r/min and above the engine Tongji University
14、 Master of Philosophy AbstractVspeed of 800r/min, strategy D with smaller fuel injection mass all over the engine speed, got lower mass emission of CO and HC.Secondly, impacts of different altitudes, coolant temperature and fuel injection strategies to particle emission of diesel engine cold start h
15、ave been studied. The results showed that increased altitude led to longer start time, I spite of decreased concentration emission of nuclear mode particulate and accumulation mode particulate, mass emission of particulate increased, at the same time, geometric mean particle diameter increased. When
16、 coolant temperature increased, concentration emission of nuclear mode particulate increased slightly, concentration emission of accumulation mode decreased obviously, geometric mean particle diameter decreased. Compared with strategy A, diesel engine cold start concentration emission of nuclear mod
17、e particulate decreased with strategy B and strategy D, concentration emission of accumulation mode particulate increased, and mass emission of particulate increased, geometric mean particle diameter increased. Compared with strategy A, diesel engine cold start concentration emission of nuclear mode
18、 particulate increased, and mass emission of particulate decreased, geometric mean particle diameter decreased. At the altitude of 3000m and 4500m, particulate mass emission was the lowest.Lastly, established start emission simulate calculation model to analyze impact of compression ratio to start e
19、mission of this diesel engine. Designed orthogonal test plan with the factors of compression ratio, temperature and fuel injection strategy, and with the aim of start emission decreasing, simulated and analyzed start emission of test diesel engine at the altitudes of 3000m and 4500m. The results sho
20、wed that start emission of CO, HC and benzoic compound(Precursor of particulate) were the lowest at the altitude of 3000m with coolant temperature of 60 , compression ratio of 15.0 and strategy with smaller fuel injection mass below the engine speed of 800r/min, reduced by 58.5%, 36.0% and 21.1%. St
21、art emission of CO, HC and benzoic compound were the lowest at the altitude of 4500m with coolant temperature of 60, compression ratio of 15.0 and strategy with smaller fuel injection mass all over the engine speed, reduced by 57.5%, 22.1% and 44.7%. Key Words: diesel engine, cold start at high alti
22、tude, emission, research同济大学 硕士学位论文 柴油机高原冷机起动排放特性研究VI目录绪论 .11.1 引言 .11.2 国内外柴油机平原环境起动性能研究现状 .31.2.1 平原环境起动燃烧性能研究 .31.2.2 平原环境起动排放性能研究 .51.3 国内外柴油机高原环境起动性能研究现状 .71.3.1 高原环境起动燃烧性能研究 .71.3.2 高原环境起动排放性能研究 .91.4 本文研究目的及主要研究内容 .91.4.1 本文研究目的 .91.4.2 本文研究内容 .9第 2 章 高原起动排放试验设置与研究方法 .112.1 试验台架搭建 .112.1.1 试验
23、用发动机和燃料 .112.1.2 气态物排放测试设备 .122.1.3 颗粒物排放测试设备 .132.1.4 发动机排气稀释和抽吸设备 .132.2 试验方案 .152.2.1 试验选取的参数和水平 .152.2.2 起动阶段划分及时间定义 .182.2.3 试验发动机工况和数据采集 .202.2.4 柴油机起动排放物质量排放计算 .202.3 本章小结 .22第 3 章 柴油机高原冷机起动气态物排放特性 .233.1 海拔高度对气态物排放的影响 .233.1.1 海拔高度对 CO 排放的影响 .233.1.2 海拔高度对 HC 排放的影响 .253.1.3 海拔高度对 NOX 排放的影响 .
24、263.2 冷却液温度对气态物排放的影响 .283.2.1 不同冷却液温度起动过程气态物排放总量 .283.2.2 柴油机不同冷却液温度起动时间 .293.2.3 冷却液温度对 CO 和 HC 浓度排放的影响 .303.2.4 冷却液温度对 NOX 浓度排放的影响 .33同济大学 硕士学位论文 目录VII3.3 供油策略对气态物排放的影响 .343.3.1 不同供油策略起动过程中气态物排放总量 .353.3.2 柴油机不同供油策略起动时间 .373.3.3 供油策略对 CO 和 HC 浓度排放的影响 .383.3.4 供油策略对 NOX 浓度排放的影响 .413.4 本章小结 .43第 4 章
25、 柴油机高原冷机起动颗粒物排放特性 .454.1 柴油机颗粒组成及形成机理 .454.1.1 柴油机颗粒物组成 .454.1.2 柴油机颗粒物形成机理 .464.2 海拔对颗粒物排放的影响 .474.3 冷却液温度对颗粒物排放的影响 .524.4 供油策略对颗粒物排放的影响 .554.5 本章小结 .60第 5 章 柴油机起动排放建模与仿真 .615.1 计算模型建立 .615.1.1 多区模型及模型分区 .615.1.2 基本控制方程 .635.1.3 发动机几何模型 .655.1.4 热力学模型 .655.1.5 传热模型 .675.1.6 化学反应模型 .685.2 模型标定验证 .715.3 压缩比对起动性能和排放的影响计算 .735.4 仿真工况点确定及正交试验设计 .745.4.1 仿真工况点确定 .745.4.2 正交试验设计 .755.5 仿真结果分析 .775.5.1 3000m 海拔 .785.5.2 4500m 海拔 .815.6 本章小结 .85第 6 章 总结与展望 .876.1 总结 .876.2 展望 .88致谢 .89参考文献 .91附录 A 正交设计仿真计算结果 .97同济大学 硕士学位论文 柴油机高原冷机起动排放特性研究VIII个人简历、在读期间发表的学术论文与研究成果 .101同济大学 硕士学位论文 目录IX
