【作者】 高章；

【导师】 颜伏伍； 刘双喜；

【作者基本信息】 武汉理工大学 ， 动力机械及工程， 2011， 硕士

【摘要】 随着不断加严的排放法规的实施,轻型汽车的污染排放得到了有效控制；但重型汽车的污染排放问题正成为许多城市环境保护和管理部门关注的焦点。公交车在城市中是保有量较大、使用较为频繁的重型车辆,是城市机动车污染排放的重要因素。本课题研究的主要内容是基于重型底盘测功机公交车整车排放测量,从而为重型整车排放和油耗标准的制定提供理论基础。针对重型柴油车排放测试方法的发展情况,分析了发动机台架测试、车载道路测试和底盘测功机测试三种测试方法的技术特点和优缺点对比。认为与台架测试方法和实际道路测试方法相比,底盘测功机在准确性和稳定性方面具有明显综合优势,未来重型底盘测试方法是评价重型整车排放的重要技术手段。调研了国内外关于重型车辆道路滑行方法研究情况和标准,对实验车辆进行道路滑行实验。分析了车辆在实际道路中和底盘测功机上所受载荷的差异,在底盘测功上再现实际道路行驶过程中的载荷。针对重型汽车排放和燃油消耗的性能评价,研究了目前国内外关于底盘测功机测试方法的研究情况,论证了建立基于整车评价的重型车辆特别是混合动力车排放和油耗性能测试方法和评价体系的必要性。本课题的主要研究成果包括以下几方面内容：(1)对试验公交车进行不同循环下的排放试验研究。分析了不同驾驶循环对公交车整车排放的影响,CCBC循环的NOX、HC、CO、CO2的里程排放因子和百公里油耗分别是WTVC循环的1.91倍、0.36倍、1.42倍、1.33倍、1.27倍；研究了不同循环下的加速、减速、匀速和怠速等不同工况对车辆排放的贡献程度,加速工况的气体污染物的分担率最高,CO和NOx的分担率高达67.1%和65.4%；分析了WTVC循环不同特征里程排放的差异,市区循环的里程排放因子高于其它两个特征里程。(2)通过采集试验车辆的相关发动机工况和状态,确定各试验循环下的发动机工作范围,分析了排放法规工况覆盖范围和实际循环下发动机运行范围的差异。认为传统法规规定的排放测试循环不能全面的反映在实际行驶过程中的整车情况。(3)比较了不同典型技术配置的公交车整车排放水平的差异。与传统柴油车对比,混合动力车常规排放物、等效C02值和百公里油耗均低于传统柴油车。CNG车辆在CO、NOX和PM排放上较传统车有一定的优势,但却表现出了较高的THC排放和等效CO2值。(4)车辆冷热状态对发动机的排放有较大影响。通过重型底盘测功机研究公交车的冷态排放和热态排放之间的差别,为今后制定法规标准提供必要的参考依据。本题研究了基于重型底盘测功机公交车整车排放测试方法,为今后公交车的实际排放估算和控制提供数据,为公交车(发动机)制造商对发动机和车辆的排放标定提供工况数据,对于提高国家测试水平具有一定的指导意义。更多还原

【Abstract】 With the implementation of the more stringent exhaust emission regulations, the emission of light-duty vehicle is controlled effectively. And the emission of Heavy-Duty Vehicle (HDV) is become a focus of the Environmental protection and management departments. The bus is a heavy vehicle of large quantities and frequent used, and is an important factor of vehicle emissions in the cities. The main content of this research is testing complete-vehicle emissions of the bus on the chassis dynamometer. This project can provide theoretical basis for drafting the regulation of the complete-vehicle emissions and fuel economy.The paper focuses on the development of the test method for emissions of HDV and analyzes the advantages and disadvantages and technical characteristics of the engine-dynamometer、on-board measurement chassis-dynamometer test method. Compared with the engine-dynamometer and on-board measurement system, the chassis-dynamometer has obvious advantages in the test accuracy and stability. So it can become the primary method of assessing the emissions of HDV in the future.The current worldwide regulations and the researches on vehicle road-coast of HDV are introduced. The project Performs experiments on the test vehicle. The different road-load between actual travel and on the chassis dynamometer is analyzed. And the chassis-dynamometer reproduced the actual travel road-load on the dynamometer.For the performance evaluation of heavy vehicle emissions and fuel consumption, the current worldwide regulations and standards for HDV on the emissions and fuel efficiency are introduced and analyzed. The necessity is discussed and demonstrated to establish a complete-vehicle based test and appraisement system for HDV emission and fuel economy.The project’s research results include the following aspect:(1) Research the emissions of different cycles on the test vehicle and analyze the influence of different cycles on emissions. The NOx、HC、CO、CO2 mileage emission factors and Hundred kilometers fuel consumption of CCBC are 1.91 times, 0.36 times,1.42 times,1.33 times,1.27 times of WTVC. Research the contribution of the different operating modes of different cycles including accelerate、decelerate、constant speed and idle. Contribution rates of accelerating models to gaseous pollutants are the highest. The contribution rates of CO and NOx is up to 67.1% and 65.4%. The emissions of different feature mileage of WTVC are studied. The experiment reveals that the emissions of downtown cycle are higher than other cycles.(2) Collect the operating modes and conditions of the engine of test vehicle and confirm the working range of different cycles. The test contrasts the difference of working range of the emission regulations cycles and actual travel cycles. The conclusion is that the emission regulations cycle can’t reflect the complete-vehicle condition in use.(3)Contrast the influence of different technologies on the complete-vehicle emissions. Compared with diesel-powered vehicle, the hybrid electric city bus (HEB) has lower common emissions, equivalent CO2 emission and fuel consumption. The CNG vehicle has advantages on the emissions control of CO、NOx and PM but has higher THC emission and CO2eqv emission.(4) The state of complete-vehicle has a great influence on the emissions. Contrast the emissions of cold-start and hot-start by chassis dynamometer and provide the reference for drafting of the regulation.The aim of the project is researching the way of testing the complete-vehicle emission of bus by chassis-dynamometer, providing the data basis for estimating and controlling of actual emissions of the bus, and offering the cycle data for emission scalibration of the engines and vehicles. This article could help to improve the testing level of our country.更多还原