CRH3动车组制动系统软管去除防火护套的安全性分析

在CRH3系列动车组运用过程中,频繁发生转向架区域及转向架与车体之间的制动软管防火护套破损、软管被磨破漏风等现象,对行车安全及运营秩序造成影响。针对此问题,从制动软管工作条件和结构角度分析故障产生的原因,提出采用不锈钢接头、无防护套的软管结构,并得到试验验证。     

克诺尔空气制动系统原理分析

空气制动是地铁车辆制动控制系统的重要组成部分。介绍广泛应用于地铁线路的德国克诺尔空气制动系统的组成,从风源装置、常用制动施加、停放制动、空气悬挂系统、风笛装置、防滑控制等的工作方式分析克诺尔空气制动系统的制动过程。     

新型轨道吸污装置吸污能力研究

采用扁形喷嘴倾斜吹风和较宽吸嘴吸风构造新型轨道吸污装置,在忽略空气的黏性力和密度变化、射流角度与气流离开轨道表面角度的差异以及吸风对吹风影响的前提下,进行新型轨道吸污装置吸污能力研究.结果表明:在临界移动速度均为10 km· h-1时,吸污风量为8×104 m3·h-1的新型轨道吸污装置与吸风风量达28×104 m3·h-1的法国VAKTRAK09系列轨道吸污装置的吸污能力相当;轨道吸污装置的临界吸污能力与临界吹风速度、临界吸风速度和临界移动速度有关,在装置的吹风、吸风速度确定后,临界吸污能力取决于装置的临界移动速度.试验证明,射流角度为60°时吸污效果更好.     

车外空气压力作用下的CRH2型动车组车内空气压力传递函数模型

根据CRH2型动车组车体气密性要求和换气系统风机特性曲线,分别建立车体内外空气通过车体等效泄漏缝隙时的泄漏空气质量流量以及新风机和废排风机的空气质量流量与车内外空气压力的线性关系式.由车内空气质量守恒定律建立在车外空气压力作用下车内空气压力响应的传递函数模型.由于动车组运行中换气系统风机特性曲线的工作点可能偏离建模时的工作点,从而导致模型涉动,故采用实测数据对传递函数模型进行修正,并通过仿真验证传递函数模型的正确性.     

螺杆式空气压缩机试验方法的探讨

主要研究机车、动车组用螺杆式空气压缩机启停机交替运转试验的试验方法,以及润滑油消耗量的测定。对比TB/T2711—2005《机车、动车用空气压缩机试验方法》,结合实验室试验经验,提出合理可行的方案。建议在标准中增加电气绝缘性能测试。     

热空气加速老化对合成闸瓦性能的影响

对铁路货车合成闸瓦进行热空气加速老化试验,研究合成闸瓦在老化过程中的力学性能和摩擦性能变化规律。结合热失重及溶胀实验结果,认为热氧老化使闸瓦中丁腈橡胶交联密度增大是闸瓦材料脆性增加、韧性变差的本质原因。     

"金荣"轮空调系统蒸发器结霜原因分析及处理措施

本文阐述了“金荣”轮空调制冷系统运行使用中蒸发器结霜的问题，针对该故障，通过分析空调制冷系统的基本结构和工作原理，查出了故障的起因，并根据本船的实际情况采取了相应的解决办法。     

The cost of convenience; Air pollution and noise on freeway and arterial light rail station platforms in Los Angeles

Light rail transit (LRT) systems constitute one of the most sustainable public transportation modes and transit agencies have increasingly constructed LRT lines along the median of roadways to reduce land acquisition costs and traffic conflicts. Despite these conveniences, few studies have examined the air pollution and noise exposures for passengers on LRT station platforms within freeway or arterial medians. In response, we monitored particle number count (PNC) concentrations and noise levels on 17 station platforms in the Los Angeles metro system in summer 2012 and assessed differences between freeway and arterial platforms. We visited each station on average 7 times for approximately 19 min with two teams carrying a full set of instruments. As expected, impacts were higher on green line platforms in the center of a grade-separated freeway compared to blue line platforms in the center of an arterial due to being in close proximity to greater traffic volumes. Overall, freeway-arterial platform differences were 35,100 versus 20,000 particles/cm³ for PNC and 83 versus 62 dBA for noise. This average noise intensity on green line platforms was four times that on blue line stations. We also found that PNC concentrations were significantly higher at open air monitoring platform positions compared to standing under a shade canopy (about 2000 particles/cm³ higher), but that noise levels were significantly lower at open air positions compared to under canopy positions (about 3.2 dBA lower). Results identify important factors for transport planners to consider when locating and designing in-roadway LRT platforms.     

The development of a decision making framework for evaluating the trade-off solutions of cleaner seaborne transportation

The general rise in marine fuel prices in combination with ever-more stringent environmental regulations resulting from IMO conventions and EU Directives have become the main industry drivers for seaborne transportation to become cleaner and more energy efficient. Compliance with existing and soon-to-be-enacted regulations requires evaluating the trade-off between often-conflicting options to select the best available technology or fuel source. Although the traditional way of dealing with this issue has been to apply a cost benefit analysis, this kind of analysis does not adequately consider the complexities of the problem, such as incorporating linguistic preferences or interrelations amongst attributes, experts and their preferences.The challenge in such an analysis corresponds to that of a multiple attribute decision-making problem in which a finite number of alternatives are assessed with regards to a finite number of attributes and experts and ranked from the best to the worst.In this paper, a comprehensive and holistic decision-making framework is proposed to overcome the barriers of cost-benefit analysis techniques, facilitating the inclusion of all possible combinations of decision-making parameters and their discrete values, which will eventually help the industry achieve cleaner seaborne transportation.To demonstrate the applicability of the proposed framework, this paper focuses on a real-life study case involving an environmental compliance problem in the Port of Copenhagen, Denmark, in relation to a particular EU Directive. In conclusion, the proposed framework can be applied as a generalised decision-making model to similar compliance issues encountered within other modes of transportation such as rail and road.     

怠速开空调车内共振问题的优化

汽车怠速工况车内噪声振动情况是影响整车NVH（噪声、振动和平顺性）水平的重要因素且影响乘车舒适性。以某款车型为例,对车内噪声源及传递路径进行分析,通过对悬置和冷却风扇等系统进行试验分析,确定了问题产生的主要原因,并提出了相应的优化方案,提出为保证悬置隔振和制冷效果,需对悬置系统和风扇转速合理匹配,同时提高转向柱的固有频率。验证表明车内轰鸣声消除,噪声及振动明显减小,效果良好,为解决同类问题提供了方法和思路。