发动机废气再循环系统的检修

废气再循环EGR(Exhaust Gas Recirculation)系统是目前用于降低发动机NOx排放的一种有效措施。它的工作好坏直接影响发动机的排放性、动力性及经济性。重点介绍了废气再循环EGR(Exhaust Gas Recirculation)系统的测试与检修,以达到对在用汽车动力性、经济性和排放性等各项性能指标提高的目的。     

降低汽车能耗的关键技术--霍尔塞特涡轮增压器在中国

随着环保成为整个社会高度重视的问题,我国政府已经认识到汽车尾气排放对于大气污染的危害性.不久前,国家环保总局发布<关于实施国家第二阶段机动车排放标准的公告>规定从2003年9月1日起,全国开始实施"第二阶段重型柴油车、重型汽油车排放标准".这标志着我国在全国范围内开始实施相当于欧Ⅱ标准的机动车排放法规.北京也承诺到2008年奥运会前达到欧Ⅲ排放标准.日趋严格的排放标准对柴油发动机提出了越来越高的技术要求.正因为如此,一个被称为"废气涡轮增压器"的产品迅速窜红了中国.采用涡轮增压技术已经成为环保的必须,涡轮增压器也将越来越成为现代汽车不可缺少的零部件之一.     

如何降低隧道无轨施工方案中柴油机有害气体的排放

隧道施工中，无轨施工方案的工程机械均采用柴油机作动力，因隧道内作业空间有限，环境恶劣，柴油机排放的废气污染严重，对工人的身体健康有危害，因此本文提出了几种可改善柴油机工作性能、降低有害物排放的方法。     

建宁西路过江通道工程废气排放方案比选研究

本文以南京市建宁西路过江通道工程为例,在设计过程中探讨了隧道废气排放的几种方案及各自特点,分析了其经济效益和环境效益,提出了三种比选方案,根据经济、技术及环境比选分析结果,推荐本工程采用“高风塔分流排污+射流式ESP废气净化装置”的组合式废气排放方案,在控制工程造价和运营成本的同时,可极大程度上减少隧道废气排放对周边环境空气质量的影响。环境影响评价结果表明,采用该方案可使隧道洞口周边空气质量满足二类环境空气功能区污染物浓度限值要求。     

船舶废气排放控制技术的探讨

文章从IMO对船舶废气排放规定出发,在总结排出物SOx、NOx的生成机理和影响因素的基础上,介绍了当前降低SOx、NOx排放污染物的技术措施。并讨论和分析了各种措施的可行性,优点,适用范围。从而提出了综合应用各种控制技术来满足降低SOx,NOx排放的要求。     

贵阳市道路公共交通CH4和N2O排放清单研究

本文采用平均速度来表征公共交通行驶对排放的影响,速度修正因子来计算欧洲NEDC下的CH_4和N_2O排放因子。对山地城市贵阳公共交通按不同燃料、车龄、车辆保有量、年平均行驶里程及测算的排放因子,建立2014年贵阳市公交车、出租车CH_4和N_2O排放清单,结果表明,天然气为燃料的公共交通是CH_4的主要来源,汽油车是N_2O排放的主要来源。因此,通过减少温室气体CH_4和N_2O的排放,是实现贵阳市发展绿色低碳健康城市有效途径。     

基于生命周期的煤电废气排放清单分析

本文以煤电生命周期的废气排放为分析和评价对象,对电煤开采、运输和燃烧发电等三个环节涉及的原料、燃料和废气等进行清单分析,得出我国基于煤电生命周期的发电废气产生的数量。     

减少柴油机排放污染的措施

柴油机的排放控制包括减少柴油机燃烧时有害成分的生成和对排气进行后处理.介绍了合理组织燃烧、改善燃料品质、进行废气再循环等减少柴油机燃烧时有害成分的措施;介绍了催化转换器、颗粒过滤器等排气后处理措施.     

内河船舶大气污染物排放影响分析

为有效减少内河船舶大气污染物排放量,降低对环境和人类健康的潜在影响,从内河船舶大气污染物排放特点入手,分析其类型、来源、排放量、影响因素、排放规律与时空分布特征等,以及内河船舶大气污染物排放对人体健康、生态环境及气候变化的影响。在此基础上提出合理控制内河船舶大气污染物排放的措施,包括燃料选择与升级、发动机优化与维护、废气后处理技术等,以期为相关从业人员提供一定的参考。     

城市道路隧道废气排放影响预测

本文在分析研究上海市延东路南线隧道废气排放影响风洞试验测定数据的基础上提出风塔排放废气影响预测高斯模式和峒口排放废气影响预测ＭＴＯＰ模式，就延安东路南线隧道为工程计算实例，取得良好模拟结果，藉助于理论分析和实测数据对比，为我国沿海地区城市道路 道大气环境评价因子，评价标准和预测模式提供必要的数据和计算论证的论据，可供同行们设计计算时参考使用。     

The effect of the price of gasoline on the urban economy: From route choice to general equilibrium

RELU-TRAN2, a spatial computable general equilibrium (CGE) model of the Chicago MSA is used to understand how gasoline use, car-VMT, on-the-road fuel intensity, trips and location patterns, housing, labor and product markets respond to a gas price increase. We find a long-run elasticity of gasoline demand (with congestion endogenous) of ?0.081, keeping constant car prices and the TFI (technological fuel intensity) of car types but allowing consumers to choose from car types. 43% of this long run elasticity is from switching to transit; 15% from trip, car-type and location choice; 38% from price, wage and rent equilibration, and 4% from building stock changes. 79% of the long run elasticity is from changes in car-VMT (the extensive margin) and 21% from savings in gasoline per mile (the intensive margin); with 83% of this intensive margin from changes in congestion and 17% from the substitution in favor of lower TFI. An exogenous trend-line improvement of the TFI of the car-types available for choice raises the long-run response to a percent increase in the gas price from ?0.081 to ?0.251. Thus, only 1/3 of the long-run response to the gas price stems from consumer choices and 2/3 from progress in fuel intensity. From 2000 to 2007, real gas prices rose 53.7%, the average car fuel intensity improved 2.7% and car prices fell 20%. The model predicts that from these changes alone, keeping constant population, income, etc. aggregate gasoline use in this period would have fallen by 5.2%.     

基于李群理论的汽油发动机尾气分析模型匹配算法研究

为了准确对发动机尾气排放状态和规律进行分析,本文提出了一种基于李群理论的汽油发动机尾气分析模型。该模型针对尾气排放量的非线性变化特征,利用李代数和李群之间的指数映射关系建立李群仿射模型,然后在流行拓扑空间上对尾气中主要污染物的含量进行建模。通过模型匹配算法实现对尾气排放状态的正常与否进行分析。该方法利用数据的流行拓扑信息,有效提高了非线性建模和匹配的准确性和效率。在福特蒙迪欧牌轿车上的实验结果表明,该模型能够以较高精度对汽油机尾气排放状况进行建模和状态匹配。     

Gas anxiety and the charging choices of plug-in hybrid electric vehicle drivers

Plug-in hybrid electric vehicles (PHEVs) can provide many of the benefits of battery electric vehicles (BEVs), such as reduced petroleum consumption and greenhouse gas emissions, without the “range anxiety” that can accompany driving a vehicle with limited range when there are few charging opportunities. However, evidence indicates that PHEVs are often plugged in more frequently than BEVs in practice. This is somewhat paradoxical: drivers for whom plugging in is optional tend to do so more frequently than those for whom it is necessary. This has led to the coining of a new term – “gas anxiety” – to describe the apparent desire of PHEV drivers to avoid using gasoline. In this paper, we analyze the variables influencing the charging choices of PHEV owners, testing whether drivers express preferences consistent with the concept of gas anxiety. We analyze data collected in a web-based stated preference survey using a latent class logit model. The results reveal two classes of decision-making patterns among the survey respondents: (1) those who weight the cost of gasoline and the cost of recharging approximately equally (the cost-minimizing class), and (2) those who weight the cost gasoline more heavily than the cost of recharging (the gas anxiety class). Respondents in the gas anxiety class expressed a willingness to recharge at a charging station even when doing so would cost approximately four times as much as the cost of the gasoline avoided. While the gas anxiety class represents the majority of our sample, more recent PHEV adopters are more likely to be in the cost-minimizing class. Looking forward, this suggests that public charging station operators may need to price charging competitively with gasoline on a per-mile basis to attract PHEV owners.     

The Alternative Motor Fuels Act, alternative-fuel vehicles, and greenhouse gas emissions

The corporate average fuel economy (CAFE) standard is the major policy tool to improve the fleet average miles per gallon of automobile manufacturers in the US. The Alternative Motor Fuels Act (AMFA) provides special treatment in calculating the fuel economy of alternative-fuel vehicles to give manufacturers CAFE incentives to produce more alternative-fuel vehicles. AMFA has as its goals an increase in the production of alternative-fuel vehicles and a decrease in gasoline consumption and greenhouse gas emissions. This paper examines theoretically the effects of the program set up under AMFA. It finds that, under some conditions, this program may actually increase the production of fuel-inefficient gasoline vehicles, gasoline consumption and greenhouse gas emissions.     

The endogeneity of OECD gasoline taxes: Evidence from pair-wise,heterogeneous panel long-run causality tests

Despite the current interest in using fuel taxes as an instrument for climate policy, there has been little study of current automotive fuel tax regimes. We expand on two earlier cross-sectional studies on why fuel taxes differ across countries by using OECD panel data and employing heterogeneous panel cointegration and long-run panel Granger-causality techniques. We confirm some of those earlier studies’ conclusions. Further, we find that governments that rely on consumption-based taxes for revenues will have higher gasoline tax rates (than governments that rely on income and wealth/property-based taxes). But more significantly, we determine that higher gasoline demand among consumers “causes” democratic governments to set lower gasoline taxes—a finding with important implications for today’s climate/energy policy debate.     

Electric vehicles for greenhouse gas reduction in China: A cost-effectiveness analysis

There have been ongoing debates over whether battery electric vehicles contribute to reducing greenhouse gas emissions in China’s context, and if yes, whether the greenhouse gas emissions reduction compensates the cost increment. This study informs such debate by examining the life-cycle cost and greenhouse gas emissions of conventional vehicles, hybrid electric vehicles and battery electric vehicles, and comparing their cost-effectiveness for reducing greenhouse gas emissions. The results indicate that under a wide range of vehicle and driving configurations (range capacity, vehicle use intensity, etc.), battery electric vehicles contribute to reducing greenhouse gas emissions compared with conventional vehicles, although their current cost-effectiveness is not comparable with hybrid electric vehicles. Driven by grid mix optimization, power generation efficiency improvement, and battery cost reduction, the cost-effectiveness of battery electric vehicles is expected to improve significantly over the coming decade and surpass hybrid electric vehicles. However, considerable uncertainty exists due to the potential impacts from factors such as gasoline price. Based on the analysis, it is recommended that the deployment of battery electric vehicles should be prioritized in intensively-used fleets such as taxis to realize high cost-effectiveness. Technology improvements both in terms of power generation and vehicle electrification are essential in improving the cost-effectiveness of battery electric vehicles.     

Real-world gaseous and particle emissions of a Bi-fuel gasoline/CNG Euro 6 passenger car

The objective of the present study is the assessment of the environmental impact of a bivalent (bi-fuel) vehicle, running either on gasoline or compressed natural gas (CNG). To that aim, a Euro 6 passenger car was tested under various real-world driving conditions. In order to cover the full range of conventional powertrains currently in the market, the tests were also repeated on a Euro 6 diesel passenger car. Both cars were driven in two routes, the first complying with the regulation limits and the second going beyond them. Carbon monoxide (CO), nitrogen oxides (NO_x) and particle number (PN) emissions were recorded using a Portable Emissions Measurement System (PEMS). Apart from the aggregated emission levels, in g/km, the exact emission location along the route was also assessed. Natural gas proved beneficial for CO and PN emissions, the level of which always remained below the respective legislation limits. On the other hand, under the dynamic driving conditions with gasoline, the relevant limits were exceeded. Cold start, occurring at the beginning of the urban part, and motorway driving were identified as major contributors to total emissions, especially in gasoline mode. However, the application of natural gas was associated with a penalty in NO_x emissions, which were significantly increased as compared to gasoline. Local peaks within the urban part were identified in CNG mode. In any case, the diesel vehicle was by far the highest NO_x emitter.     

Life cycle model of alternative fuel vehicles: emissions,energy, and cost trade-offs

This paper describes a life cycle model for performing level-playing field comparisons of the emissions, costs, and energy efficiency trade-offs of alternative fuel vehicles (AFV) through the fuel production chain and over a vehicle lifetime. The model is an improvement over previous models because it includes the full life cycle of the fuels and vehicles, free of the distorting effects of taxes or differential incentives. This spreadsheet model permits rapid analyses of scenarios in plots of trade-off curves or efficiency frontiers, for a wide range of alternatives with current and future prices and levels of technology. The model is available on request.The analyses indicate that reformulated gasoline (RFG) currently has the best overall performance for its low cost, and should be the priority alternative fuel for polluted regions. Liquid fuels based on natural gas, M100 or M85, may be the next option by providing good overall performance at low cost and easy compatibility with mainstream fuel distribution systems. Longer term, electric drive vehicles using liquid hydrocarbons in fuel cells may offer large emissions and energy savings at a competitive cost. Natural gas and battery electric vehicles may prove economically feasible at reducing emissions and petroleum consumption in niches determined by the unique characteristics of those systems.     

HCCI内燃机工作过程控制方式研究及技术前景展望

本文介绍了均质压燃(HCCI)内燃机的工作过程及技术特点,重点阐述了对其工作过程的控制方式,并对其未来发展前景进行了展望,同时点明了其当前面临的技术挑战。HCCI内燃机是近年来广受关注的一类新型内燃机,其兼具传统汽油机及柴油机的技术优势,尽管其目前依然存在一定的技术挑战,但随着相关技术的不断完善与优化,其必将得以广泛应用。