A review of hydrogen technologies and engineering solutions for railway vehicle design and operations

Interest in hydrogen-powered rail vehicles has gradually increased worldwide over recent decades due to the global pressure on reduction in greenhouse gas emissions,technology availability,and multiple options of power supply.In the past,research and development have been primarily focusing on light rail and regional trains,but the interest in hydrogen-powered freight and heavy haul trains is also growing.The review shows that some technical feasibility has been demonstrated from the research and experiments on proof-of-concept designs.Several rail vehicles powered by hydrogen either are currently operating or are the subject of experimental programmes.The paper identifies that fuel cell technology is well developed and has obvious application in providing electrical traction power,while hydrogen combustion in traditional IC engines and gas turbines is not yet well developed.The need for on-board energy storage is discussed along with the benefits of energy management and control systems.

Atomic-scale engineering of advanced catalytic and energy materials via atomic layer deposition for eco-friendly vehicles

Zero-emission eco-friendly vehicles with partly or fully electric powertrains have exhibited rapidly increased demand for reducing the emissions of air pollutants and improving the energy efficiency. Advanced catalytic and energy materials are essential as the significant portions in the key technologies of eco-friendly vehicles, such as the exhaust emission control system,power lithium ion battery and hydrogen fuel cell. Precise synthesis and surface modification of the functional materials and electrodes are required to satisfy the efficient surface and interface catalysis, as well as rapid electron/ion transport. Atomic layer deposition(ALD), an atomic and close-to-atomic scale manufacturing method, shows unique characteristics of precise thickness control, uniformity and conformality for film deposition, which has emerged as an important technique to design and engineer advanced catalytic and energy materials. This review has summarized recent process of ALD on the controllable preparation and modification of metal and oxide catalysts, as well as lithium ion battery and fuel cell electrodes. The enhanced catalytic and electrochemical performances are discussed with the unique nanostructures prepared by ALD. Recent works on ALD reactors for mass production are highlighted. The challenges involved in the research and development of ALD on the future practical applications are presented, including precursor and deposition process investigation, practical device performance evaluation, large-scale and efficient production, etc.

Numerical analysis of temperature rise within 70MPa composite hydrogen vehicle cylinder during fast refueling

The numerical simulation model for predicting fast filling process of 70 MPa type Ⅲ(with metal liner) hydrogen vehicle cylinder was presented,which has considered turbulence,real gas effect and solid heat transfer issues.Through the numerical analysis method,the temperature distributions of the gas within the solid walls were revealed; adiabatic filling was studied to evaluate the heat dissipation during the filling; the influences of various filling conditions on temperature rise were analyzed in detail.Finally,cold filling was proposed to evaluate the effect on temperature rise and SoC(state of charge) within the cylinder.The hydrogen pre-cooling was proved to be an effective solution to reduce maximum temperature and acquire higher SoC during the filling process.

Hydrogen Shows Promise in Vehicle Tests

Car fleets escorted by police along Chang’an Avenue are not a rare sight for Beijing residents, who are accustomed to the practice when leaders of foreign states visit the capital of China.

Techno-Economic Optimization of Novel Stand-Alone Renewable Based Electric Vehicle Charging Station near Bahria Town Karachi,Sindh Pakistan

Electric vehicles (EVs) are the most interesting and innovative technology in the 21st century because of theirenormous advantages, both technically and economically. Their emissions rate compared to fuel-based vehicles isnegligible as they do not consume fuel and hence do not emit any harmful gases. However, their bulk production,adoption and lack of charging stations increase the stress of power stations due to modern-day lifestyles. If Electricvehicles demand increases drastically then conventional power stations will not bear their demand and if theygenerate electricity by conventional means it will be very costly and may further add greenhouse gases. Therefore,this research provides the techno-economic assessment of a stand-alone renewable-dependent electric vehiclecharging station, excluding any burden on electrical utility. The proposed study is carried out in Bahria Town,Karachi, a city in Pakistan. In this study, HOMER Pro software was utilized for techno-economic assessment. Ahybrid system comprising solar Photovoltaic/Wind Turbine/Fuel cells and battery storage is included in the model.Solar and wind resources were taken from NASA’s website, where charging stations will be integrated. The overallresults show promising in terms of total Net Present Cost and the Cost of Energy which are 2.72M $ and 0.237 $,respectively. The total system generation is 3,598 Megawatt hours per year, and the total energy consumption is 885Megawatt hours per year.

考虑HFCV加氢不确定性的电-氢-交通系统多主体博弈运行

针对难以综合处理电-氢-交通系统中多重不确定性和多主体交互的问题,提出一种考虑氢燃料电池汽车(HFCV)加氢不确定性的电-氢-交通系统多主体博弈运行策略。首先,构建配电网运营商、制氢加氢站(HPRS)运营商和HFCV用户之间的能量和利益交互机制及博弈框架。其次,考虑实时交通路网车流量,提出一种HFCV用户出行及加氢行为的精细化建模方法,基于Wasserstein距离建立HFCV加氢负荷不确定性模型。然后,在配电网运营商、HPRS运营商和HFCV用户三主体间构建以各主体利益最大为目标的双层主从博弈分布鲁棒运行模型,并利用对偶原理和Slater条件转化求解。最后,采用IEEE 69节点配电网与TN 25节点交通网组成的耦合系统验证所提模型的有效性。

氢燃料电池特性试验分析研究

在“双碳”目标及可持续发展战略背景下,氢燃料电池汽车备受国内外关注,其在节能减排、环保方面作用重大。但氢燃料电池汽车发展受制氢与储氢技术、燃料电池特性及稳定性等因素限制。为发挥燃料电池的环保价值,文章主要对氢燃料电池汽车的发展现状及电池特性进行分析和研究,期望能促进氢能产业发展,加快燃料电池升级,推进氢燃料汽车发展,推动汽车产业绿色节能。

车载液氢瓶六点支撑与八点支撑方案热力耦合特性对比研究

氢能作为一种绿色清洁能源,在新能源汽车领域受到了广泛关注。尤其是低温液氢存储,因具有储氢密度高等优势而成为了一种理想的车载储氢方式。车载液氢瓶是液氢燃料车的关键部件之一,其支撑结构将直接影响到整个液氢瓶的绝热性能和力学性能。采用有限元分析方法,从强度校核、模态分析和随机振动疲劳分析三个方面,对基于六点支撑方案和八点支撑方案的液氢瓶结构进行了对比分析,研究结果表明,玻璃钢柱皆采用10 mm径向厚度时,八点支撑方案能够达到强度校核标准,但六点支撑方案却不能满足强度要求;为了满足强度校核条件,六点支撑方案中需增加玻璃钢柱的径向厚度,但这也导致了更大的支撑漏热;设计参数下,六点支撑方案和八点支撑方案中的支撑漏热分别为23.65 W和22.49 W,疲劳寿命分别为1.01×107次和9.19×107次;相较于八点支撑方案,六点支撑方案中液氢瓶虽然减少了支撑端的数量,但绝热性能并没有得到有效提升,且使用寿命反而大幅降低。

燃料电池汽车侧柱碰撞安全性研究及应用

燃料电池汽车因其具备燃料系统的特殊性,区别于传统汽车和纯电动汽车,故其在碰撞安全性研究方面也多了新的课题。文章针对某款燃料电池汽车,实车验证其在当前不同的碰撞安全标准工况,即在中国保险汽车安全指数(C-IASI)50 km/h侧面碰撞、中国新车评价规程(C-NCAP)50 km/h侧面碰撞和32 km/h侧面柱碰撞工况下的表现,通过假人伤害值和车门的最大变形量对比,从而确认在侧面柱碰工况下对于该款燃料电池汽车考查更为严苛。又通过仿真对比分析了该车在侧面柱碰工况下不同风险点的损伤程度,从而确定了在氢泄漏安全方面最严苛的风险位置,即前氢阀的位置。基于该风险位置进行了碰撞试验,确认了其气体泄漏的原因,并进行相应的结构优化,通过仿真分析和实车侧柱碰撞验证了优化方案的可行性,为燃料电池汽车碰撞安全性研究提供了一定的参考。

燃料电池商用车供氢系统发展趋势与研究

随着环保意识的日益增强,氢燃料电池车因其能量效率高、无污染、噪音小等优点而备受关注。然而,储氢系统作为氢燃料电池车的核心组成部分,其储氢系统的局限性,如储氢质量小、续航里程短、自重大、成本高等问题,制约了燃料电池商用车的发展。文章重点探讨了不同储氢方式在燃料电池商用车的应用,并对高压气态储氢系统的集成化、轻量化、大容积化、国产化等方面进行了深入研究与分析。最后,对未来车载供氢系统的发展及攻关方向进行了展望。

Dispatching Fuel-cell Hybrid Electric Vehicles Toward Transportation and Energy Systems Integration

With the increasing integration of traditional elec-tric vehicles(EVs),the ensuing congestion and overloading issues have threatened the reliability of power grid operations.Hydrogen has been advocated as a promising energy carrier to achieve low-carbon transportation and energy(trans-energy)systems,which can support the popularization of fuel-cell hybrid EVs(FCHEVs)while enhancing the flexibility of power grids.In this paper,we propose an optimal scheduling framework for trans-energy systems that evaluates the merits of the hydrogen supply chain from water electrolysis,compressed storage and transportation to FCHEV utilization.A detailed FCHEV model is established,and mileage is modeled as a function of the stored electricity and hydrogen mass.A stochastic programming-based scheduling model is formulated,which minimizes the total cost of unit commitment and the hydrogen supply chain.The Dijkstra algorithm is adopted to search the shortest path for hydrogen transportation.Case studies demonstrate that FCHEVs can reduce the operational costs of tran-energy systems and facilitate the accommodation of renewable energy when compared to traditional EVs.Index Terms-Fuel-cell hybrid electric vehicle,hydrogen,mileage model,shortest path search,trans-energy systems.

Distributed Bio-Hydrogen Refueling Stations

Hydrogen fuel cell cars are now available for lease and for sale. Renewable hydrogen fuel can be produced from water via electrolysis, or from biomass via gasification. Electrolysis is power-hungry with high demand from solar or wind power. Gasification, however, can be energy self-sufficient using a recently-patented thermochemical conversion technology known as I-HPG （indirectly-heated pyrolytic gasification）. I-HPG produces a tar-free syngas from non-food woody biomass. This means the balance of plant can be small, so the overall system is economical at modest sizes. This makes it possible to produce renewable hydrogen from local agricultural residues; sufficient to create distributed refueling stations wherever there is feedstock. This work describes the specifics of a novel bio-hydrogen refueling station whereby the syngas produced has much of the hydrogen extracted with the remainder powering a generator to provide the electric power to the I-HPG system. Thus the system runs continuously. When paired with another new technology, moderate-pressure storage of hydrogen in porous silicon, there is the potential to also power the refueling operation. Such systems can be operated independently. It is even possible to design an energy self-sufficient farm where all electric power, heat, and hydrogen fuel is produced from the non-food residues of agricultural operations. No water is required, and the carbon footprint is negative, or at least neutral.

车用氢能发展难点与对策

“双碳”目标背景下,国内加快能源转型步伐,交通运输业作为第三大碳排放行业,加快向电、氢转型。分析了国内氢燃料电池汽车和加氢站的发展现状,从产业链的角度深入剖析了国内车用氢能发展的“车贵”“氢贵”“站贵”等三大痛点,认为深层次的原因是燃料电池、车辆生产和加氢站设备生产存在技术瓶颈,关键零部件仍然依赖进口,加氢站建设及运营成本高,电解水等制氢成本高等。最后,从行业发展的角度,分别提出了降低车用氢能成本的突破路径,指导行业良性发展。

车用液氢气瓶快充过程数值研究

车用液氢气瓶加注过程中,因加注速度快且气瓶容积小,极易造成过充现象,导致安全事故发生。针对设有气包防过充装置的车载液氢气瓶建立三维对称模型,采用CFD方法对气瓶快速加注过程开展数值仿真。分析了开孔孔径、加注速率、初始充满率和防过充装置容积对防过充装置性能的影响规律。结果表明:开孔孔径是影响防过充装置性能的主要因素,其限制了液体的流通能力;采用6 mm孔径和初始充装量为50%的状况下,充装结束后气瓶都将过充,最大充装率可达98.4%;采用大容积的防过充装置可以为气瓶预留更多的气相安全空间,但同时也会导致充装量不足等问题,当防过充装置容积为100 L时,最终充装量仅有77.2%。

考虑不同制氢方法的高速公路加氢站布局规划

针对高速公路加氢设施不完善的问题,提出一种基于改进自适应遗传算法的高速公路加氢站布局方法。根据高速公路特性及电子收费记录,建立高速公路网络和加氢判断模型。基于多层次-模糊综合评价方法,从经济性、环保性以及安全性角度,提供适合高速公路加氢站的制氢方法和制氢地点的组合。再结合分布式光伏的投入,以经济效益最优为目标,构建高速公路站外和站内制氢2组目标函数,利用改进自适应遗传算法分别进行优化布局和容量配置。以沈海高速(浙江段)作为研究对象进行分析,提供了不同制氢方法下加氢站布局方案及相关设施的容量配置,算例结果与模糊综合评价结果相互验证了模型的有效性。

基于TD3-PER的氢燃料电池混合动力汽车能量管理策略研究

为优化氢燃料电池混合动力汽车的燃料经济性及辅助动力电池性能,提出了一种基于优先经验采样的双延迟深度确定性策略梯度(TD3-PER)能量管理策略。采用双延迟深度确定性策略梯度(TD3)算法,在防止训练过优估计的同时实现了更精准的连续控制;同时结合优先经验采样(PER)算法,在获得更好优化性能的基础上加速了策略的训练。仿真结果表明:相较于深度确定性策略梯度(DDPG)算法,所提出的TD3-PER能量管理策略的百公里氢耗量降低了7.56%,平均功率波动降低了6.49%。

氢燃料电池汽车在风洞试验中的氢泄漏扩散分析

采用数值模拟方法,研究氢燃料电池汽车在发生氢泄漏情况下,氢气在风洞内部的流动扩散规律与分布情况。当风洞模拟汽车以80 km/h行驶工况时,车底部泄漏的氢气紧贴着汽车表面向后移动进入汽车的尾流区,氢气浓度随着离汽车尾部距离的增加而降低。从收集口进入流道内的氢气集中在中、底部,具有明显的浓度梯度,经过风扇区后变得均匀;10 s后车底泄漏的氢气又重新回到试验段,与车底正在泄漏的氢气汇合,造成整个区域氢气浓度的持续升高。由于风洞流道拐角导流片的存在,流道内测的氢气浓度升高的更快。当风洞模拟汽车怠速工况时,泄漏的氢气大多在试验段内流动扩散,流道内几乎检测不到氢气。受试验段内气流扰动的影响,汽车两侧的氢气呈现出不对称分布,顶部的氢气集中在车左侧。根据数值模拟结果给出了氢浓度传感器的安装位置建议。

基于FLACS的船舶载运燃料电池汽车氢气泄漏仿真分析

为保障船舶载运燃料电池汽车(FCV)安全,以某滚装船为研究对象,基于FLACS软件模拟闭式滚装处所和开式滚装处所内氢气泄漏场景,对比分析几种不同通风型式、通风效率、泄漏位置及车辆间距对氢气泄漏扩散的影响。结果表明,针对闭式处所,机械进风叠加机械排风的通风效果最好,机械进风叠加自然排风效果次之,自然进风叠加机械排风效果最差;相同进排气型式下,换气次数越多对处所内氢气浓度下降越有利,在通风阻滞区域尤其明显;相同风向和风速条件下,船舶中部氢气泄漏的后果风险明显高于端部,中部氢气泄漏后处所通风达到安全浓度的时间为端部的3~12倍。

考虑交通流量预测的光−氢−电耦合系统规划

为解决制氢、加氢站建设成本高、氢燃料汽车加氢具有不确定性特点等问题,提出一种考虑交通流量预测的光−氢−电耦合系统规划模型。首先,建立包含氢气生产、压缩和储存并通过充氢装置注入至氢燃料电池汽车内的现场制氢模型;其次,提出交通流量的预测方法,为制氢、加氢站系统建模和运行提供支持;最后,以最小化成本为目标,构建考虑交通流量预测的光−氢−电耦合系统规划模型,然后以IEEE30标准算例,以30路网节点为算例分析系统,研究发现制氢、加氢站联合光伏电站有利于降低系统成本;制氢补贴政策的实施使氢气需求增加28%,制氢、加氢站数量增加20%;电解槽制氢量快速响应峰谷分时电价变化。结果表明所提模型具有有效性。

车用氢能储供阀门测试标准比较研究

氢能一直以来是全球能源界关注的重点,燃料电池汽车是氢能应用与发展的重要领域。氢气属于易燃易爆且小分子易泄漏气体,车用氢能储供阀门作为车载供氢系统的关键部件,产品的安全性能关系到整车的安全性和稳定性。本文通过对国内外车用氢能储供阀门常用的测试标准的比较研究,着重对GB/T 42536、EU406和GTR13三个标准的测试试验项目进行比较,对标准的试验要求进行了分析和总结,为更好地理解和应用标准提供了借鉴,对于车用氢能产业的发展具有重要的意义。