完善甲醇汽车使用技术的研究方向及技术方案

目前,真正实现甲醇燃料能够在发动机及车辆正常使用,必须从燃料消耗的替比率、动力输出、日常维护费用等诸多方面,达到同使用汽油燃料相比,一个性能稳定而方便,燃料消耗费用低的水平。这一理念的实现,是建立在完善甲醇燃料两大技术系统之上的。一个技术系统是运用合理的燃料添加剂解决甲醇作为替代燃料,改变燃料自身存在的缺陷,使之成为改性甲醇燃料;另一技术系统是开发适用甲醇燃料的发动机辅助设备和日常专用维护产品。这样才能达到经济推广,广泛使用的目的。     

EQ6100发动机液化石油气燃料高原改造方案试验研究

目前云南城市客车主要主要是以汽油为燃料的化油器汽车,车辆主要装备EQ6100发动机,车辆所排出的废气是城区大气污染源的重点之一。云南地处高原,发动机充气效率下降,而且液化石油气装置与发动机不匹配,缺乏必要的高原调整技术方案。本文应用试验的方法,对EQ6100发动机的液化石油气装置的选择、发动机的改造及液化石油气装置的调整都进行了深入研究和探讨,确定了EQ6100发动机高原液化石油气燃料高原改造方案。     

金豹LNG卡车运输项目

液化天然气(LNG)汽车是继压缩天然气(CNG)和液化石油气(LPG)汽车之后的一种新型环保汽车。其特点是汽车车载瓶内加注的是液态的天然气,与CNG相比携带天然气量更多、续驶里程长(300～1200km左右)、气质洁净;与柴油车相比低温启动性好。通过该项目,新疆金豹物流有限公司将原有的运输车辆全部改造或更新为以液化天然气(LNG)为燃料的车辆。通过一年的运营,在取得了良好的经济效益的同时,也达到了节能减排的效果。     

汽车日常维护的研究

随着国内经济的发展和国民收入水平的提高,汽车进入到千家万户,方便了人们的出行。在道路状况复杂的环境下,往往因为汽车维护不当造成汽车性能降低,给人们出行带来不便,增加了消费者的养车成本,给行车安全带来隐患。对此,文章结合对汽车保养维护的研究,提出了汽车日常维护的作业方法,旨在提升对汽车各方面常规检查的专业性和有效性,为消费者进行车辆日常维护提供参考。通过对汽车的日常维护的介绍,能够使人们明白其重要性,从而减少故障率和事故发生率,为行车安全提供最基本的保障。     

恒通客车:领秀中国燃气客车市场60年

燃气客车是以天然气作为燃料的客车,按照天然气的化学成分和形态,可分为压缩天然气(CNG)客车、液化天然气(LNG)客车和液化石油气(LPG)客车3种。作为一种理想的低污染车,燃气客车被公认为是世界上最值得推广的高节能、低污染、经济、安全的新型代用燃料客车。作为中国燃气客车的创始者、推进者与领跑者,恒通客车始终走在节能减排前沿,凭借其60余年燃气客车技术积淀以及     

恒通客车：领秀中国燃气客车市场60年

燃气客车足以天然气作为燃料的客车，按照天然气的化学成分和形态，可分为压缩天然气（CNG）客车、液化天然气（LNG）客车和液化石油气（LPG）客车3种。作为一种理想的低污染车，燃气客车被公认为是世界上最值得推广的高节能、低污染、经济、安全的新型代用燃料客车。     

基于碳平衡原理的天然气汽车燃料消耗量检测方法研究

文章通过分析天然气组份及天然气发动机的燃烧特性,基于碳平衡原理建立了天然气汽车燃料消耗量计算模型。对比分析了闭式和开式碳平衡检测系统的结构工作原理及适用范围,确定采用开式稀释采样方式进行天然气燃料消耗量检测系统开发。结合天然气汽车燃料消耗量计算模型中的技术参数需求,设计开发了碳平衡气耗仪。为了分析设备工作的可靠性和测量的准确性,选用LNG宇通客车和东风危险品运输车作为试验样车,利用科里奥利质量流量计对其进行标定。通过对比试验可知,碳平衡气耗仪与科里奥利质量流量计相对误差为5%,基本满足在用天然气汽车燃料消耗量检测的需求。     

LNG清洁能源汽车在城市公交中的应用并向道路客运推广

天然气作为清洁能源,与汽油、柴油相比具有显著的经济性和环保性。近年来,随着国家对绿色环保的要求逐年提高,降低汽车尾气排放任务更加艰巨。本项目通过推广使用液化天然气(LNG)车辆,采用液化天然气替代燃油,大幅度减少了汽车有害尾气排放,减少温室气体CO2排放约四分之一。项目针对LNG的理化性能与特点,在车辆性能优化配置、机务保障、驾驶操作等方面开展了大量工作,对其运行效果做出了具有实践意义的综合评价,积累了成熟的经验,并在道路客运车辆上大力推广,对道路运输实现节能减排与能源结构调整具有示范和引导作用。     

LNG燃料动力船在广西内河推广应用的思考

文章分析了液化天然气(LNG)在航运业推广应用的必要性和以LNG作为船舶动力燃料的主要危险特性,介绍了国内外LNG燃料动力船改造应用的基本情况及难点,提出了广西内河现有船舶进行LNG动力改造面临的主要问题与对策,为LNG燃料动力船在广西内河的推广应用提供参考。     

国内外新型环保车用替代燃料研究现状

为了降低汽车对石油燃料的依赖,同时满足日益苛刻的环保要求,及早研究探索新型汽车代用清洁能源势在必行。目前各国科学家积极研究的汽车代用燃料主要有液态氢、液态天然气以及煤基合成油。与液态氢、液态天然气和煤基合成油相比,固体天然气水合物的优点很多,有可能成为未来新型的汽车燃料。     

Failure rates and data driven policies for vehicle safety inspections in Pennsylvania

Rail, truck, commercial bus, and aircraft have federally mandated safety inspection programs in the United States, while inspections of personal vehicles, which make up the majority of passenger miles, are optionally imposed at the state level. In recent years, some states have chosen to eliminate the vehicle safety inspection program because of budget constraints and concerns about program effectiveness. Currently, 26 states have a schedule for conducting safety inspections, but Pennsylvania is one of thirteen states that currently require all personal light duty vehicles to be inspected every year. The remaining states have completely eliminated safety inspection programs. However, as automobiles become safer, Pennsylvania legislators are now pushing to phase out the inspection program to reduce the costs of owning a vehicle. This study combines Pennsylvania vehicle registration data with two large samples of results from state safety inspections. We find that the state safety inspection fail rate for light-duty vehicles is 12–18%, well above the often-cited rate of 2%. Vehicles that are older than three years old or have more than about 30,000 miles can have much higher rates. When analyzing new vehicles, less than or equal to one year old, it is found that even these vehicles have a failure rate greater than zero. Furthermore, while the vehicle fleet appears to be getting safer over the past few years by improvements in technology or other external circumstances, the inspection failure rate does not appear to be trending toward zero in the near future. We also show that accurate inspection data is limited and often incorrectly analyzed. Lastly, the importance of vehicle maintenance over a vehicle’s lifetime is proven to be evident, since regular usage causes vehicles to deteriorate. We conclude that vehicle safety inspections should continue to be implemented in order to keep driving conditions safe.     

Well-to-wheel assessment of natural gas vehicles and their fuel supply infrastructures – Perspectives on gas in transport in Denmark

In this paper, potential natural gas and renewable natural gas supply pathways and natural gas vehicles (NGVs) have been selected and evaluated with regards to well-to-wheel energy expended, greenhouse gas (GHG) emissions, and regulated (air pollutant) emissions. The vehicles included in the evaluation are passenger cars, light-duty vehicles (LDVs), and heavy-duty vehicles (HDVs) for road-transport applications, and a short-range passenger vessel for maritime transport applications. The results show that, compared to conventional fuels, in both transport applications and for all vehicle classes, the use of compressed and liquefied natural gas has a 15–27% GHG emissions reduction effect per km travel. The effect becomes large, 81–211%, when compressed and liquefied renewable natural gas are used instead. The results are sensitive to the type and source of feedstock used, the type of vehicle engine, assumed methane leakage and methane slip, and the allocated energy and environmental digestate credits, in each pathway. In maritime applications, the use of liquefied natural gas and renewable natural gas instead of low sulfur marine fuels results in a 60–100% SOx and 90–96% PM emissions reduction. A 1% methane slip from a dedicated LNG passenger vessel results, on average, in 8.5% increase in net GHG emissions.     

Probabilistic analysis of the release of liquefied natural gas (LNG) tenders due to freight-train derailments

Liquefied natural gas (LNG) has emerged as a possible alternative fuel for freight railroads in the United States, due to the availability of cheap domestic natural gas and continued pursuit of environmental and energy sustainability. A safety concern regarding the deployment of LNG-powered trains is the risk of breaching the LNG tender car (a special type of hazardous materials car that stores fuel for adjacent locomotives) in a train accident. When a train is derailed, an LNG tender car might be derailed or damaged, causing a release and possible fire. This paper describes the first study that focuses on modeling the probability of an LNG tender car release incident due to a freight train derailment on a mainline. The model accounts for a number of factors such as FRA track class, method of operation, annual traffic density level, train length, the point of derailment, accident speed, the position(s) of the LNG tender(s) in a train, and LNG tender car design. The model can be applied to any specified route or network with LNG-fueled trains. The implementation of the model can be undertaken by the railroad industry to develop proactive risk management solutions when using LNG as an alternative railroad fuel.     

The development of a prescreening model to identify failed and gross polluting vehicles

The California State Bureau of Automotive Repair uses a high-emitter profile model to direct, or screen a fraction of the vehicle fleet in for inspection and maintenance testing at test-only facilities. Reviews by the California Inspection/Maintenance Review Committee showed the high-emitter profile to be inefficient and in need of improvement. In this study, using in-use vehicle emissions data from California’s statewide smog check program, we specified a new multinomial logit model designed to improve the screening efficiency for targeting potential failed and gross polluting vehicles. Modeling results show that factors such as odometer reading, model year, vehicle make, as well as the presence of emissions control systems are significant factors in predicting the likelihood that a screened vehicle will test as a failed or a gross polluting vehicle. Comparisons indicate that the new multinomial logit model specification can predict various inspection/maintenance test outcomes more accurately than the existing high-emitter profile model.     

Policing the poor: The impact of vehicle emissions inspection programs across income

Comparing vehicle emissions inspection results with vehicle owner income shows that the Arizona vehicle emissions inspection program constrains the vehicle repair decisions of people in the low end of the income distribution more than people in the high end. Individuals who live in areas with lower annual income are both (i) more likely to drive vehicles that fail emissions inspections at a higher average rate, and (ii) more likely to fail emissions inspections conditional on vehicle characteristics. The top income quintile fails emissions inspections 20% less often than the bottom income quintile even when controlling for observable vehicle characteristics. This implies that owner characteristics, in addition to observable vehicle characteristics, have a non-negligible impact on vehicle emissions rates. Therefore, the impact of programs designed to reduce vehicle emissions could be greater if participation were subject to a means test.     

新型管道环焊缝相控阵超声检测设备的研制

目前,相控阵超声检测技术在国内长输管道环焊缝检测中得到了广泛应用,由于专用相控阵检测电缆在施工中容易损坏,使得设备维护成本高昂。在已有的相控阵技术研究基础上,设计了新型管道环焊缝相控阵超声检测设备,使超声采集单元及电机驱动控制单元小型化,安装在扫查器上,采集的超声信号经网线传输到笔记本电脑,实现全自动超声检测功能。经现场试验测试,设备性能满足《管道对接环焊缝全自动超声波检测标准》要求。     

基于材料就地再生的多功能养护车作业工艺及经济效益分析

多功能养护车是完成沥青路面病害快速处置的现代化作业机具,而将路面材料的就地再生利用作为养护车的标准配置是其作业功能的重要拓展,且是道路养护现代化的主要标志之一。探讨路面材料再生工艺及相关技术参数的优化对于保证和提高再生材料的路用质量、降低加热能源消耗和环境保护具有重要的现实意义。     

Statistical modeling of vehicle emissions from inspection/maintenance testing data: an exploratory analysis

Many metropolitan areas in the United States use vehicle inspection and maintenance (I/M) programs as a means of identifying high-polluting vehicles. While the effectiveness of such programs is debatable, the cost is undeniable, with millions of dollars spent in testing and millions more lost in the time motorists expend to participate in such programs. At the core of these costs is the blanket approach of requiring all vehicles to be tested. This paper sets the groundwork for a procedure that can be used to selectively target those vehicles most likely to be pollution violators. Using I/M data collected in the Seattle area in 1994, carbon monoxide, carbon dioxide and hydrocarbon emissions were modeled simultaneously using three-stage least squares. Our results show that vehicle age, vehicle manufacturer, number of engine cylinders, odometer reading, and whether or not oxygenated fuels were in use all play a significant role in determining I/M emission test results and these statistical findings can be used to form the basis for the selective sampling of vehicles for I/M testing.     

重型清障车吊臂和托臂的优化设计及应力分析

清障车是一种具有道路抢险作业装备,能够起吊和托起事故、违章或损坏车辆,并能快速离开事故现场的专用车辆。文章采用UG软件对吊臂模型处理,通过其自带软件NX NASTRAN对托臂总成进行有限元分析,根据实际作业工况对托臂总成进行约束与载荷施加,使托臂的强度分析更具有可信度。其结果为吊臂和托臂总成的设计及优化提供了参考依据。     

LNG项目柔性材料管道保冷施工

随着液化天然气（LNG）项目的不断发展,新型的管道保冷材料被广泛应用。文中结合某LNG项目管道柔性保冷材料的实际施工情况,对柔性保冷材料的施工工艺从环境要求、保冷结构、施工顺序等几个方面进行研究,总结出了最适合的保冷施工工艺,为其他LNG项目管道保冷材料的选型提供参考,为管道保冷施工提供参考。