Greenhouse gas emission analysis and measurement for urban rail transit: A review of research progress and prospects

Rail transit plays a key role in mitigating transportation system carbon emissions.Accurate measurement of urban rail transit carbon emission can help quantify the contribution of urban rail transit towards urban transportation carbon emission reduction.Since the whole life cycle of urban rail transit carbon emission measurement involves a wide range of aspects,a systematic framework model is required for analysis.This research reviews the existing studies on carbon emission of urban rail transit.First,the characteristics of urban rail transit carbon emission were determined and the complexity of carbon emission measurement was analyzed.Then,the urban rail transit carbon emission measurement models were compared and analyzed in terms of the selection of research boundaries,the types of greenhouse gas(GHG)emissions calculation,and the accuracy of the measurement.Following that,an intelligent station was introduced to analyze the practical application of digital collaboration technology and energy-saving and carbon-reducing system platforms for rail transit.Finally,the urgent problems and future research directions at this stage were discussed.This research presents the necessity of establishing a dynamic carbon emission factor library and the important development trend of system integration of carbon emission measurement and digital system technology.

Life Cycle Assessment of CCA-Treated Wood Highway Guard Rail Posts in the US with Comparisons to Galvanized Steel Guard Rail Posts

A cradle-to-grave life cycle assessment is done to identify the environmental impacts of chromated copper arsenate (CCA)-treated timber used for highway guard rail posts, to understand the processes that contribute to the total impacts, and to determine how the impacts compare to the primary alternative product, galvanized steel posts. Guard rail posts are the supporting structures for highway guard rails. Transportation engineers, as well as public and regulatory interests, have increasing need to understand the environmental implications of guard rail post selection, in addition to factors such as costs and service performance. This study uses a life cycle inventory (LCI) to catalogue the input and output data from guard rail post manufacture, service life, and disposition, and a life cycle impact assessment (LCIA) to assess anthropogenic and net greenhouse gas (GHG), acidification, smog, ecotoxicity, and eutrophication potentially resulting from life cycle air emissions. Other indicators of interest also are tracked, such as fossil fuel and water use. Comparisons of guard rail post products are made at a functional unit of one post per year of service. This life cycle assessment (LCA) finds that the manufacture, use, and disposition of CCA-treated wood guard rails offers lower fossil fuel use and lower anthropogenic and net GHG emissions, acidification, smog potential, and ecotoxicity environmental impacts than impact indicator values for galvanized steel posts. Water use and eutrophication impact indicator values for CCA-treated guard rail posts are greater than impact indicator values for galvanized steel guard rail posts.

A Life Cycle Cost Analysis Model of Goods Movement for the Gulf Cooperation Council Region

In this article,a total life cycle cost analysis(LCCA)was developed covering two transportation systems:trucking and railway within the Gulf Cooperation Council(GCC)region.GCC region is a regional intergovernmental political and economic union consists of six countries(Saudi Arabia,Kuwait,the United Arab Emirates,Qatar,Bahrain,and Oman).In general and based on statistics,the GCC regional economy is expected to grow due to the increase in aggregate supply and demand.So,there is a need to build a solid foundation of transportation systems that can help in transforming this region into a logistics hub.Therefore,different analysis was discussed in order to be able to select more reliable and appropriate mode of shipping between the GCC.Beside the main cost factors that which includes the capital,operational,maintenance and depreciation costs.Other factors such as,border delays,emissions,noise and safety factors were added to the analysis.The results show that,shipping using trucking system can be cheaper when shipping commodities between the GCC region,but at the same time considering border delays and emission produced,railways and intermodal modal systems prove to be more reliable.Moreover,shipping bulk commodities favor the rail and intermodal systems due to the payload capacity besides the flexibility of finding the most efficient way to move the shipments between origin and destinations.

Some Critical Issues in the Development of Chinese High-Speed Rail: Challenges and Coping Strategies

In this paper, several critical issues related to Chinese high-speed rails (CHSR) are analyzed, investigated and discussed, including development background, reasons for high ticket fare, some typical factors that influence the environmental life-cycle assessment, time and cost comparison of typical door-to-door travel routes between different transport modes and complementary strategies among different transport modes. First, the results show that the expanding high-speed rail network increased the pressure on the country's roads in the 2010 spring festival rush period due to the high ticket fare of CHSR. Second, due to lower than expected ridership because of the high ticket price and limited demand in less developed areas, some Chinese CHSR projects have become economically unsustainable. Third, without sufficient ridership and service life, the utilization of HSR was unable to show any advantages in the environmental impact compared with the other transport modes. In addition, the impact of shock from CHSR on Chinese domestic civil airlines is evident when the travel distance is below 1050 km. The key objective of the investigation is to enhance our understanding of the development and operation of Chinese high-speed rail. One of the key contributions of the current paper is the presented suggestions for complementary strategies between different transport modes to make full use of Chinese transportation resources to promote low carbon economy.

基于实际地铁线路的全生命周期碳排放研究

在双碳战略的重大战略部署下,对轨道交通全生命周期碳排放进行研究,合理量化其碳排放水平是实现交通部门碳达峰、碳中和的重要措施。本文基于北京某新建地铁线路,对轨道交通全生命周期碳排放进行分析,建立了轨道交通全线、全生命周期的碳排放计算模型,并定量计算新建地铁线路全线、全生命周期的碳排放量。同时,对建设阶段和运营阶段的降碳措施做出分析,定量评估其降碳潜力。对全长81 km新建地铁线路进行碳排放量计算,得到建设阶段碳排放量为257万t CO_(2)eq,运营阶段为5.35万t CO_(2)eq/a,50年运营周期总计碳排放量524万t CO_(2)eq。建设阶段使用可再生材料及预制结构可减少碳排放量7%;运营阶段综合采用多种节能降碳措施后,可降碳27%;50年运营周期降碳潜力总计17%。该模型的建立对城轨交通全生命周期碳排放定量计算有指导意义,降碳措施的研究成果以期为城轨交通完成绿色低碳转型、实现交通部门碳达峰、碳中和提供参考。

基于安全知识库的轨道交通安全预评价方法

在当前城市轨道交通快速发展的需求下,国内轨道交通安全相关系统的预评价方法尚不成熟,积累的各类故障、事故案例无法得到有效共享,导致实际工程中预评价工作难以开展。首先,构建了基于本体推理规则的Man(人员)、Machine(设备)、Media(环境)、Management(管理)及Mission(任务)的5M多因素信号系统安全知识库。其次,阐述信号系统预评估过程,结合案例分析和应用,形成了基于安全知识库的轨道交通安全预评价方法。最后,从风险辨识质量和风险控制精准度等多方面将基于安全知识库的轨道交通安全预评价方法与一般预评价方法进行比较,结果表明该方法能够从全生命周期角度对信号系统分阶段风险进行辨识并评定风险损失,风险辨识质量高、风险控制精准度高,且该方法的实施有利于加强城市轨道交通事前安全管理效果,同时也可为安全相关系统的风险预评价理论研究提供参考。

城市轨道交通数字孪生标准体系研究

随着国家“新基建”战略对于建设数字孪生城市建设的指引,我国城市轨道交通工程作为城市公共基础设施的重要组成部分进入了新的发展时期,通过构建数字孪生体系将会加快推动城市轨道交通工程全生命周期智能化进程。本文主要研究了城市轨道交通数字孪生标准体系构建的重点方向:首先阐述了城市轨道交通数字孪生标准体系构建的目的与意义以及当前城市轨道交通数字孪生标准化现状,并就标准体系构建的重点原则进行了分析;其次结合目前制造业的数字孪生模型架构和技术体系,建立了城市轨道交通领域的数字孪生标准体系架构;最后结合国内目前城市轨道交通领域技术体系标准制定的现状,详细分析了物理实体、虚拟实体、平台与服务、连接与集成等技术标准的构建基础与思路,以期促进数字孪生技术在我国城市轨道交通领域的全面推广应用。

监测数据驱动的城轨列车轴箱轴承剩余寿命预测

城轨列车轴箱轴承的运行工况复杂多变、外部随机干扰频繁,导致其监测数据中包含大量测量噪声乃至“脏”数据,进而制约了剩余寿命预测模型的精度.为解决上述问题,提出了一种监测数据驱动的动态多重聚合剩余寿命预测方法.首先,通过度量短时数据的幅值分布相似性自动识别并清洗“脏”数据;然后,将健康指标按不同时间尺度进行动态聚合,预测出各类潜在的未来退化轨迹,进而获得轴箱轴承的剩余寿命预测均值与方差;并使用现场实测数据与加速寿命实验数据对提出方法进行验证.结果表明:所提方法能有效剔除监测数据中的空采数据和强干扰数据;剩余寿命预测均值随累计行驶里程的增加逐渐收敛到真实值,且95%置信区间越来越窄;相比于单指数预测模型和混合预测模型,提出方法的累计相对精度平均值分别提高了29.78%和27.63%,预测收敛速度平均值分别增加了10.56%和10.20%.

车辆转向架转臂定位节点疲劳寿命可靠性研究

[目的]基于虚拟仿真疲劳试验技术,对某型车辆转向架的转臂定位节点进行疲劳寿命分析及可靠性评估,以提高车辆稳定性并保障列车安全运行。[方法]利用ABAQUS软件建立转臂定位节点有限元模型,获取应力应变数据;通过FE-SAFE软件设置橡胶材料的疲劳参数,进行疲劳寿命仿真分析;采用图检验法对伪失效疲劳寿命进行分布假设检验,选取最优寿命分布;利用寿命分布参数值与应力水平之间的关系拟合出适合的函数关系式,对正常应力水平下转臂定位节点的疲劳寿命进行可靠性评估。[结果及结论]转臂定位节点在正常应力水平下仅有橡胶衬套将产生疲劳损伤;橡胶衬套最下端为伪失效疲劳寿命值最低的区域,也是最先发生破坏的区域;现场试验与疲劳仿真结果验证了转臂定位节点有限元模型的准确性;确定了最优的正态寿命分布;正常应力水平下,转臂定位节点可靠度为0.9时的疲劳寿命循环次数大约为21万次。

基于专利视角的制氢技术成熟度分析

为响应国家“双碳”目标,推动清洁能源的发展和利用,合理规划布局制氢技术路线,首先对专利初始数据进行处理,构建测度数据集,并基于构建的测度指标体系计算得到了技术成熟度值;其次,根据技术成熟度值拟合技术生命周期曲线,确定了每种制氢技术所处的技术生命周期阶段;最后,从技术应用广度、技术先进性、技术竞争潜力、技术影响力4方面对技术成熟度进行了综合分析。结果表明:目前最普遍使用的煤气化制氢技术已进入衰退期,而电解水制氢技术近年来发展较快,已经进入成熟阶段,预计未来一段时间内将快速成长为主流制氢技术路线。中国应围绕技术潜力较大的制氢路线,通过渐进替代以实现制氢结构的绿色、高效,助力能源结构转型。

道岔大轨件全生命周期管理信息系统的设计与实现

为解决道岔大轨件(简称:大轨件)台账记录方式落后、现场作业人员无法快速掌握设备信息、备件重复利用不充分等问题,设计实现了大轨件全生命周期管理信息系统。该系统优化大轨件全生命周期管理流程,精确、实时掌控大轨件服役状态,采用网页端与手持终端App相结合的形式,强化生产作业过程管控,保障大轨件信息获取与更新的时效性,已在某工务段试点应用,并取得良好的试用效果,验证了该系统对大轨件信息化管理的实际意义。

FMECA(故障模式、影响及危害性分析)分析法在车辆检修规程中的应用

[目的]为了减少因个人主观因素而产生的分析偏差,提高可靠性分析活动输出结果的可信程度,采用FMECA(故障模式、影响及危害性分析)分析法分析城市轨道交通车辆系统的可靠性。[方法]介绍了FMECA分析法的内涵及其基本流程,以及故障模式下部件可靠性危害度计算方法和危害度分析步骤。采用该方法实例分析了上海轨道交通12号线车辆各部件的风险等级,并以此为基础优化了检修周期。[结果及结论]通过识别,有针对性地检查高危害度部件,适当延长低危害度部件的检修周期,再结合一些轨旁和在线检测设备,能够降低企业的用工成本。在目前车辆可靠性未有明显变化的前提下,相较于传统检修规程,新检修规程下每列列车人工检修工时下降超过10%。

基于RCM的车辆设备服役寿命分析抽样方案

[目的]为了支持车辆RCM(以可靠性为中心的维修)规程落地实施,增加通过RCM分析得到的RCM规程的维修任务以及维修间隔的科学性和可信度,需研究一种合理的用于分析车辆设备服役寿命的抽样方法。[方法]以车辆设备中的车钩为研究对象,介绍了车钩抽样总体流程、初始任务清单确认流程和抽样任务清单确认流程;基于GBT 2828.1—2012制定了包括抽样方法、抽样数量、抽样间隔及相关参数计算方法在内的车钩抽样方案。以上海轨道交通17号线17A01型列车车钩为例,采用该抽样方案确定了不同类型车钩的抽样方案。[结果及结论]根据该抽样方案可对不同的车辆设备进行抽样检查,获取设备的真实状态,可弥补诸如车钩这种高可靠性设备的故障数据少、故障规律较难获取,导致难以定义维修周期的问题。该抽样方案为分析车辆设备服役寿命提供了一种合理且经济的实施方案,也为车辆RCM规程落地实施提供了技术支撑。

城市轨道交通工务检修车辆配置的探讨

在系统分析城市轨道交通常用工务维修车辆的功能基础上,结合多个城市的工程设计经验及运营单位的调研,从线网资源共享角度,对工务维修车辆的配置方式提出了建议,为今后工程设计中工务维修车辆的合理配置提供参考。

武汉地铁全生命周期BIM数字化平台建设与应用

近年来,国家和地方陆续出台城市轨道交通行业数字化转型的政策与法规,鼓励和支持城市轨道交通行业和相关产业升级迭代。文章以武汉地铁BIM全生命周期数字化平台规划与建设为例,阐述武汉地铁在加快推进建筑信息模型(BIM)技术在武汉市轨道交通工程规划、勘察、设计、施工和运营维护全过程的集成应用,实现轨道交通工程建设项目全生命周期数据共享和信息化管理,为轨道交通项目方案优化和科学决策提供依据,促进轨道交通行业提质增效。

基于EN 50126-1的城轨车辆防火安全评估方法研究

随着城轨车辆防火要求的不断提高,我国城轨车辆防火独立安全评估的概念逐渐形成,但也存在理论研究薄弱、行业认识不统一及评估人员匮乏等问题。文章通过借鉴建筑消防领域“对照规范评定”的成熟方法,提出了“符合性检查为主、偏离风险管控为辅”的城轨车辆防火安全评估策略,梳理了从确定评估依据到确定整车防火安全水平的具体实施步骤;参考EN 50126-1标准中的安全生命周期“V”模型,划分了方案设计、技术设计、生产制造和测试验收四个评估阶段,并全面阐述了各个阶段的防火安全评估任务、检查重点和注意事项;建立防火安全评估的组织架构、接口关系,并提出相关人员的能力要求。

Induced life cycle transition from holocycly to anholocycly of the Russian wheat aphid (Homoptera: Aphididae)

The Russian wheat aphid (RWA), Diuraphis noxia (Mordvilko),exists with holocyclic life cycle in Tacheng, Xinjiang in Northwest China. It produces males and oviparae to mate and oviposit for overwintering by eggs. Under laboratory conditions with 14 h/d photophase and temperature not lower than 15℃, RWA occurred in parthenogenesis and produced no males. The laboratory popu-lations of Russian wheat aphid, which were kept under natural conditions in fall by 15th, 49th and 81st generation while wild populations produced males and oviparae for mating, produced males and oviparae with their number decreased gradually, but viviparae and nymphs increased sequen-tially. As a result, it produced a small amount of oviparae and no males emerged in fields by 49 generations' reproduction in laboratory. After development of 81 generations, oviparae happened occasionally and no eggs occurred for overwintering instead of viviparae and nymphs. A hypothesis of RWA disastrous process was proposed. The life cycle of RWA can be changed from holocycly to anholocycly in its long-term spread and evolution. Anholocycly is more dangerous than holocycly to small grains for its strong adaptability and dispersal ability.

煤炭在中国农村生活能源中的利用与退出路径

碳中和对我国农村能源革命和能源转型提出了加速发展的更紧迫要求,煤炭退出农村生活能源系统是大势所趋,关键在于如何有序、有效、公平、高质量地退出。基于农村生活能源全品类谱系的消费量与碳排放,回顾评估1949年以来煤炭在我国农村生活能源系统中的作为、地位与影响;基于北京农村调查分析政策性退出煤炭的问题与挑战;进一步结合有效能需求评价与预测,系统分析农村生活能源系统碳中和转型的韧性、经济性和差异化瓶颈,预判煤炭在未来农村生活能源系统中的地位与贡献,探索煤炭退出机制。主要结论:(1)我国农村人均生活能耗及有效能需求均处于增长通道,全电力模式下未来农村居民生活用电峰值预计人均5 000 kW·h。(2)长远看,农村生活能源电气化将是以碳中和、可再生、市场化为核心特征的电气化。煤炭退出机制重在推动农村生活能源系统朝“清洁”能源转型,是“煤炭替代”与“替代煤炭”的有机综合。在农村绿色能源市场还没有充分发展之前,煤炭依然是确保农村能源安全的首选“压舱石”。(3)基于区域差异,提出跨越煤炭、煤炭替代(煤炭替代生物质,清洁煤升级)与替代煤炭(自愿退煤,强制禁煤)3类共5种能源转型路径,分类施策,组合发展。未来我国农村居民生活将享有一个富有韧性与公平性的现代化碳中和能源系统。

轨道交通橡胶材料多通道疲劳试验机的研制及应用

针对轨道交通橡胶材料疲劳性能试验,设计了一种新型带有高低温环境箱18通道单轴拉伸疲劳试验机,并与现有橡胶材料疲劳试验方案进行了分析比对,重点应用新型试验机对2种试样进行了3种不同应力水平的拉伸疲劳试验,获取了橡胶材料载荷与疲劳次数曲线。结果表明,新型试验方案结构设计合理,各项功能均满足橡胶材料疲劳寿命预测试验要求;疲劳载荷增大,橡胶材料疲劳次数减小,尤其在高应力水平区变化最为明显,试样2#疲劳性能优于试样1#。

城市轨道交通基于智能运维的维护管理新模式研究

随着我国城市化进程不断推进,城市轨道交通的建设、运营、管理规模不断扩大。规模巨大的网络化运营带来了设施设备规模大、故障数量多、维护强度大、可用资源少等若干问题。智能化的维护管理通过对城市轨道交通系统及设施设备进行在线监测、健康状态评估、故障诊断和剩余寿命预测,并根据监测、诊断、预测结果按需制定针对性维护策略,从而达到降低设施设备故障率、提高城轨系统可靠性和鲁棒性、优化维护成本的目的。以北京城市轨道交通为例,简述城市轨道交通设施设备的维护管理现状,基于城市轨道交通智能运维大背景,对城市轨道交通设施设备智能维护管理新模式进行探讨,提出设施设备大数据应用管理模式、设施设备智能维护模式以及网络化维护资产智能联动模式,推动我国城市轨道交通维护管理模式向更智能化的方向发展。