天然气汽车加气站发展趋势及LCNG加气站技术特点

叙述了目前世界上压缩天然气(CNG)汽车加气站和液化天然气(LNG)汽车加气站的加气流程和相关运行设备,对目前新型液化压缩天然气(LCNG)天然气加气站的加气原理进行了简单描述,并比较了LCNG加气站和CNG加气站的优劣,介绍了目前国外的天然气汽车和加气站的发展现状及趋势。     

对我国发展天然气汽车的建议

我国正面临空气污染的严重威胁,而多个国家的经验告诉我们,推广天然气汽车是改善空气质量的有效手段。我国目前重点出台扶持政策推广纯电动汽车,但效果欠佳,主要原因一是充电不方便,二是充电时间长,三是销售价格高且性价比低,这些问题在短期内恐无法解决。相对于纯电动汽车,天然气汽车不存在上述问题,更具有在短期内推广的优势。天然气加气站普及建设更加便利,完全可以将效益不好的加油站改装为加气站,或改装为油气混合站;天然气汽车一般几分钟就可完成加气,与加油时间基本相当;同时价格低,成本回收快,更易被市场和用户所接受;另外在二氧化碳减排方面,天然气汽车也不逊于电动汽车。目前影响我国天然气汽车发展的主要问题是优惠政策少,油气价差小,加气困难,管网建设未能大范围普及。建议应推行差别定价,对天然气汽车充气实行比工业和化工用气更低的价格,并辅以财税优惠;研究推行油气混合站,加强在加油站增设充气设施的研究和实践;同时要加快天然气管网建设,充分利用国内外两个市场,推动我国天然气汽车的发展。     

天然气作为汽车替代燃料的分析

本文统计了天然气作为汽车燃料的发展情况，分析了天然气汽车的特点，着重介绍了液化天然气汽车的系统构成、技术性能及其加气站的构造及特点。     

LNG加气站工艺技术与安全探究

叙述了液化天然气加气站工艺技术流程,分析了液化天然气加气站工艺技术的安全性和经济性,指出,液化天然气汽车的普遍推广已经成为当前的发展重点。     

国内外天然气汽车和加气站的发展现状及在我国的发展前景(二)

本文详细介绍了我国CNG汽车和加气站发展状况、世界各国鼓励天然气汽车发展的政策,对比了CNG、汽油和LPG作车用燃料在性能和经济上的优缺点。指出随着我国经济的发展、国家对环境保护工作的重视以及燃油税费改革政策的出台,压缩天然气汽车由于其良好的社会和经济效益大有可为,也将成为天然气市场开发的一个新领域。最后,提出了一些促进我国天然气汽车和加气站发展的建议。     

国内外天然气汽车和加气站的发展现状及在我国的发展前景(一)

本文详细介绍了我国CNG汽车和加气站发展状况、世界各国鼓励天然气汽车发展的政策,对比了CNG、汽油和LPG作车用燃料在性能和经济上的优缺点。指出随着我国经济的发展、国家对环境保护工作的重视以及燃油税费改革政策的出台,压缩天然气汽车由于其良好的社会和经济效益大有可为,也将成为天然气市场开发的一个新领域。最后,提出了一些促进我国天然气汽车和加气站发展的建议。     

CNG汽车加气站安全运行管理

在CNG汽车数量逐年增多的背景下,CNG加气站的安全运行管理也日益受到重视。通过对CNG汽车加气站事故进行分析,将CNG汽车加气站分为售气区域和生产区域,由此进一步分析得出引发加气站事故的原因主要有:售气区域天然气气质不合格,售气机频繁使用加速破损老化,员工违规操作以及加气车辆自身存在问题;生产区域储气系统、压缩系统和天然气预处理系统均存在诸多危险因素。因此针对加气站安全生产薄弱环节,提出相应的安全运行管理策略:设备管理方面需要定期查漏,保证设备安全运行,加气站合理规划建设,制定防护和减灾措施;人员管理方面需要加强从业人员岗位培训,提高从业人员素质;CNG汽车加气站建设应合理规划布局,提高CNG加气站的规范性与安全性,以加强CNG加气站安全管理,尽可能消除安全隐患,减少火灾爆炸等各类事故的发生。     

天然气汽车及天然气加气站的经济性分析

论述了国内外天然气汽车的发展现状与趋势,对天然气汽车和天然气加气站进行了经济分析,指出天然气作为汽车替代燃料具有一定的经济优势和较大的环保效益,快速发展天然气汽车产业对改善城市大气环境具有重要意义.     

发展天然气汽车存在的问题及对策

石油价格上涨,促进了天然气汽车的发展。天然气汽车的优势在于环保和节能。我国目前存在的问题是加气站点不足,汽车的动力性下降,对发动机有一定的腐蚀。解决的途径是政府扶持,改进发动机结构,使用专用的润滑油等。     

液化天然气汽车技术及存在问题探讨

推广和应用液化天然气汽车（LNGV）是降低汽车排放污染的有效途径，文章介绍了LNG的理化特性，安全性，LNGV车载燃料系统和LNGV加气站技术，对LNGV在实际应用中存在的问题作了一些探讨。     

Development of natural gas vehicles in China: An assessment of enabling factors and barriers

Replacing conventional gasoline or diesel vehicles with natural gas vehicles (NGVs) is necessary if China hopes to significantly reduce its greenhouse gas emissions in the short term. Based on city-level data, this paper analyzes the enabling factors and barriers to China's NGV development. We find that a shortage in natural gas supply and a relatively high price ratio of natural gas compared to gasoline are the main factors impeding China's NGV development. Imbalanced development between natural gas refueling stations and NGVs also hinder the popularity of these lower-carbon vehicles. While various policies have been implemented in recent years to promote NGVs in China, only those encouraging adoption of NGVs by the private sector appear effective. To promote further NGV development in China, the following strategies are proposed: (1) improve natural gas delivery infrastructure across the country; (2) reasonably reduce the relative price of natural gas compared to gasoline; (3) give priority to middle-income and medium-sized cities and towns, since siting natural gas refueling stations is easier in these areas; and (4) promote the use of NGVs in the private sector.     

Single-tank storage versus multi-tank cascade system in hydrogen refueling stations for fuel cell buses

Many countries in Europe are investing in fuel cell bus technology with the expected mobilization of more than 1200 buses across Europe in the following years. The scaling-up will make indispensable a more effective design and management of hydrogen refueling stations to improve the refueling phase in terms of refueling time and dispensed quantity while containing the investment and operation costs. In the present study, a previously developed dynamic lumped model of a hydrogen refueling process, developed in MATLAB, is used to analyze tank-to-tank fuel cell buses (30–40 kg_H2 at 350 bar) refueling operations comparing a single-tank storage with a multi-tank cascade system. The new-built Aalborg (DK) hydrogen refueling station serves as a case study for the cascade design. In general, a cascading refueling approach from multiple storage tanks at different pressure levels provides the opportunity for a more optimized management of the station storage, reducing the pressure differential between the refueling and refueled tanks throughout the whole refueling process, thus reducing compression energy. This study demonstrates the validity of these aspects for heavy-duty applications through the technical evaluation of the refueling time, gas heating, compression energy consumption and hydrogen utilization, filling the literature gap on cascade versus single tank refueling comparison. Furthermore, a simplified calculation of the capital and operating expenditures is conducted, denoting the cost-effectiveness of the cascade configuration under study. Finally, the effect of different pressure switching points between the storage tanks is investigated, showing that a lower medium pressure usage reduces the compression energy consumption and increases the station flexibility.     

The daimler-benz hydride vehicle project

Thirty passenger cars with hydrogen and hydrogen/gasoline hybrid operation and TiFe hydride tanks will be tested in Berlin. A central refueling station will deliver pure hydrogen derived out of the town gas network. High and low temperature hydride tanks will be tested in some vans and passenger cars in Stuttgart. An individual refueling station with integrated heat recovery will demonstrate the possibility of using existing energy infrastructures (electricity, gas) for hydrogen production.     

Performance analysis of a new tank configuration applied to the natural gas storage systems by adsorption

This work presents a numerical study of a new tank configuration applied to natural gas storage systems by adsorption. The traditional tanks employed in natural gas storage by adsorption reveal serious limitations for use in fast charge systems because of their inefficiency in the dissipation of adsorption heat. In order to eliminate the detrimental effects of adsorption heat, and to make viable the fast charge of gas in automotive tanks, a vessel made up of several tubes, compacted with activated carbon, was proposed. In the charge process, the gas circulates through the tank and all non-adsorbed gasses pass through an external heat exchanger installed close to the gas source of the refueling station. The numerical results obtained in the present work showed that the charge time of the new system can vary from 50 to 200 s, depending on the applied mass flow rate. These time periods are considered satisfactory for fast charge conditions. Another advantage of this new system is that there will be no need to include the accessories employed in traditional tanks, such as: fins, perforated tube in the tank center and a cooling external jacket, which would increase the complexity of the vessel design.     

Developing an infrastructure for hydrogen vehicles: a Southern California case study

We have examined the technical feasibility and economics of developing a hydrogen vehicle refueling infrastructure for a specific area where zero emission vehicles are being considered, Southern California. Potential hydrogen demands for zero emission vehicles are estimated. We then assess in detail several near term possibilities for producing and delivering gaseous hydrogen transportation fuel including: (1) hydrogen produced from natural gas in a large, centralized steam reforming plant, and truck delivered as a liquid to refueling stations; (2) hydrogen produced in a large, centralized steam reforming plant, and delivered via small scale hydrogen gas pipeline to refueling stations; (3) by-product hydrogen from chemical industry sources; (4) hydrogen produced at the refueling station via small scale steam reforming of natural gas; and (5) hydrogen produced via small scale electrolysis at the refueling station. The capital cost of infrastructure and the delivered cost of hydrogen are estimated for each hydrogen supply option. Hydrogen is compared to other fuels for fuel cell vehicles (methanol, gasoline) in terms of vehicle cost, infrastructure cost and lifecycle cost of transportation. Finally, we discuss possible scenarios for introducing hydrogen as a fuel for fuel cell vehicles.     

Addition of hydrogen refueling for fuel cell bus fleet to existing natural gas stations: A case study in Wuhan,China

Hydrogen refueling is an essential infrastructure for fuel cell vehicles, and currently, it appears to be a critical service needed to initiate the highly anticipated hydrogen economy in China. A practical selecting procedure of adding hydrogen refueling service to existing natural gas (NG) stations is proposed in this study. A case study in Wuhan, China, is established to assess the feasibility and future planning. The demand for hydrogen fuel and initial supply chain of hydrogen in Wuhan are estimated based on the deployment objective of fuel cell buses. The existing NG stations are evaluated based on 300 kg/day to determine whether they meet the hydrogen safety requirement using Google map or field investigation. The safety space requirement of the hydrogen refueling area on existing NG station is determined as 25.9 × 27.1 m². The optimal hydrogen refueling plan for fuel cell buses is calculated with multi‐objective analysis in economic, environmental, and safety aspects from the view of the hydrogen refueling supply chain. It is shown that adding hydrogen refueling stations to existing NG stations is feasible in technology, economics, regulation, and operation considerations. This study provides guidelines for building the hydrogen infrastructure for fuel cell buses at their early stage of commercial operation.     

Quantitative risk assessment of a mobile hydrogen refueling station in Korea

Hydrogen infrastructure is expanding. Mobile hydrogen refueling stations are advantageous because they can be moved between locations to provide refueling. However, there are serious concerns over the risk of various accident scenarios as the refueling stations are transported. In this study, we conduct a quantitative risk assessment of a mobile hydrogen refueling station. Risks that may occur at two refueling locations and the transport path between them are analyzed. Our evaluation reveals that risks are mostly in an acceptable zone and to a lesser degree in a conditionally acceptable zone. The greatest single risk factor is an accident resulting from the rupture of the tube trailer at the refueling site. At sites with no tube trailer and during the transport, the risk is greatest from large leaks from the dispenser or compressed gas facility. The mobile hydrogen refueling station can be safely built within acceptable risk levels.     

The co-evolution of alternative fuel infrastructure and vehicles: A study of the experience of Argentina with compressed natural gas

In a quest for strategic and environmental benefits, the developed countries have been trying for many years to increase the share of alternative fuels in their transportation fuel mixes. They have met very little success though. In this paper, we examine the experience of Argentina with compressed natural gas. We conducted interviews with a wide range of stakeholders and analyzed econometrically data collected in Argentina to investigate the factors, economic, political, and others that determined the high rate of adoption of this fuel. A central objective of this research was to identify lessons that could be useful to developed countries in their efforts to deploy alternative fuel vehicles. We find that fuel price regulation was a significant determinant of the adoption of compressed natural gas, while, contrary to expectations, government financing of refueling infrastructure was minimal.     

燃气机热泵变负荷特性的试验研究

燃气机热泵是一项高效节能技术，在试验条件下其一次能源利用率PER为1．13～1．79。为了解交负荷时燃气机热泵的性能，通过试验得到了燃气机热泵的发动机负荷特性、发动机余热回收和燃气机热泵的总体特性曲线。结果表明：随着发动机转速的增加，燃气机热泵的COP和PER是下降的，但下降的幅度较为平缓，且保持较高的数值。通过对IPL Vcop值的分析，发现燃气机热泵的IPL Vcop比热泵系统的大，这说明燃气机热泵的部分负荷性能好，可以很好地实现交负荷运行。     

A review and prospects of gas mixture containing hydrogen as vehicle fuel in China

Nowadays, the environmental problems caused by the burning of fossil fuels as vehicle fuel have become more and more serious in the world. Many countries are carrying out the research on the alternative energy sources and the clean energy. Meanwhile, China has begun to focus on the development of the gas mixture containing hydrogen as the vehicle fuel, mainly hydrogen enriched compressed natural gas (HCNG) and coke oven gas (COG). Application status of HCNG and COG as the vehicle fuel in China were reviewed and their existing problems were analyzed. The analysis results shows that the relevant regulations standards of HCNG vehicle, COG vehicle and their refueling stations have not been formulated and unified yet and the optimal hydrogen ratio of the HCNG requires further experimental investigation and theoretical analysis. In addition, as a country with substantial COG wasted, China can make better use of the wasted hydrogen contained in COG to realize the miniaturization and closed production of the COG without pollution. HCNG and COG as vehicle fuel are beneficial for the development of the hydrogen energy, which can alleviate the crisis of global energy shortage and effectively reduce the production and emission of sulfur oxides. Therefore, the prospects of HCNG and COG as the vehicle fuel are good in China.