压力容器材料的选用及其相关要求

提出了实践中遇到的压力容器材料的选用及其相关要求应注意的问题。     

储氢材料的储热功能

介绍了储氢材料的储热功能及其热能转换系统。     

储氢材料的储电功能研究

本文着重介绍了国外电解水－发电系统，储氢材料在化学电源中的应用以及燃料电池发电等方面的研究情况。     

两种双配体金属有机骨架材料的合成及储氢性能研究

采用溶剂热合成法,利用对苯二甲酸(1,4-bdc)分别与三乙烯二胺(dabco)、均苯三甲酸(1,3,5-btc)作为配体,合成了Zn2 (bdc)2 (dabco)和Zn3 (bdc)( btc)2两种双配体金属有机骨架材料,运用XRD、TGA、N2吸附等手段对其进行表征.Zn2 (bdc)2 (dabco)在温度为100℃条件下获得相对结晶度最高的样品,Zn3( bdc)( btc)2在温度为150℃条件下获得相对结晶度最高的样品.以热重分析数据为依据,将样品在373K温度下活化,在77K温度下进行储氢测试,测得其在5bar压力下的储氢量分别为2.59wt％、0.38wt％.     

碳纳米纤维吸附储氢性能评价

利用N2(T=77K)、H2(T=298K)在三种碳纳米纤维材料中的吸附等温线，对这三种材料的吸附储氢性能进行了评价。以N2在77K下的吸附等温线为基础，分别用BET方法和BJH方法计算了这三种材料的比表面积和孔径分布，讨论了比表面积、孔径分布和吸附性能之间的关系。计算和实验结果表明：这三种材料均只含有少量的微孔，吸附性能较差。在三种后处理方法中，以水蒸气氧化法的效果最好，所得材料比表面积最大，微孔容积所占比例也最大，相应的吸附性能也最好。     

镁基固态储氢材料的研究进展

氢能有望成为脱碳时代的“理想燃料”。高性能储氢材料的发现、开发和改性是未来发展固态储氢和氢能源利用的关键。而氢化镁(MgH₂)具有储氢能力强、自然储量丰富、环境友好等特点,在固态储氢材料领域备受关注。但是氢化镁较高的热力学稳定性、缓慢的动力学性能,以及循环过程中不可避免的团聚和粗化等问题在一定程度上限制了镁基固态储氢材料的大规模投产和实际应用。近年来,大量研究工作聚焦于镁基储氢材料的热/动力学改性,目前已经取得了大量的成果。本文通过回顾国内外相关文献,综述了改善镁基固态储氢材料储氢性能的最新研究进展,着重介绍了合金化、纳米化、引入催化剂等改性策略,阐述了不同策略具体的改性机理。最后对未来的发展方向进行了展望,旨在为高性能镁基储氢材料的研发提供借鉴与指导。     

吊杆的材料选用和尺寸计算

对上海锅炉厂有限公司锅炉吊杆的材料选用和尺寸计算作了简单介绍;针对原吊杆尺寸计算中材料许用应力的选取已不适应当前材料许用应力的确定准则-安全系数已被修改的状况,通过调整吊杆计算标准中的许用应力以及螺纹端计算截面积来减小吊杆的尺寸规格.     

碳材料吸附储氢技术

主要介绍了碳材料的吸附储氢性能,结构特点及研究动向。     

金属氢化物复合式高压储氢器的研究

为提高高压储氢容器的体积储氢密度,采用具有高体积储氢密度的储氢合金与轻质高压容器复合组成高压金属氢化物复合式储氢器.为获得高压氢源,研究了Mm-Ml-Ni-Al(Mm为富铈混合稀土,Ml为富镧混合稀土)的储氢特性,并试制了化学热压缩器.采用研制的高压氢源,对具有高吸放氢平台压力的Ce-Ni系合金的高压储氢特性进行了研究.实验结果表明:以Ml或Ca部分取代Mm以及Al对Ni的部分置换后合金活化性能和吸放氢压力滞后明显改善,(Mm-Ml)0.8Ca0.2(Ni-Al)多元合金具有较好的储氢性能,适合于作为化学热压缩合金.CeNi5基多元合金在40MPa氢压条件下,合金具有较好的活化性能和吸放氢动力学性能,合金最大储氢容量分别达到1.6wt%.将优化的储氢合金与自制的轻质高压储氢容器复合组成的金属氢化物复合式高压储氢器,当储氢合金的填充量达到0.2(体积分数)时,其体积储氢密度提高50%.     

空气预热器冷端金属温度和材料选用

针对空气预热器受热面的酸性腐蚀，确立了合理选用受热面材料的设计导则，并帮助锅炉运行人员在提高锅炉热效率和降低空气预热器受热面维修成本二者之间保持较佳的运行经济性。     

Fatigue life evaluation of high pressure hydrogen storage vessel

By combining the micromechanics and continuum damage mechanics, a theoretical model is proposed to perform the fatigue evaluation of high pressure hydrogen storage vessel under cyclic internal pressure, which concentrates on the fatigue properties of the aluminum liner. Results show that the fatigue lifetime of vessel relates to the finite element mesh size, crack density and ratio in an element, cyclic loading amplitude and stress status at the liner. Effects of the mesh size and crack density on the fatigue lifetime of vessel are discussed. In addition, numerical results are also compared with those by experiments.     

Optimal design of high pressure hydrogen storage vessel using an adaptive genetic algorithm

The weight minimum optimization of composite hydrogen storage vessel under the burst pressure constraint is considered. An adaptive genetic algorithm is proposed to perform the optimal design of composite vessels. The proposed optimization algorithm considers the adaptive probabilities of crossover and mutation which change with the fitness values of individuals and proposes a penalty function to deal with the burst pressure constraint. The winding thickness and angles of composite layers are chosen as the design variables. Effects of the population size and the number of generations on the optimal results are explored. The results using the adaptive genetic algorithm are also compared with those using the simple genetic algorithm and the Monte Carlo optimization method.     

Ignition of hydrogen jet fires from high pressure storage

Self-ignition behaviour of highly transient jets from hydrogen high pressure tanks were investigated up to 26 MPa. The jet development and related ignition/combustion phenomena were characterized by high speed video techniques and time resolved spectroscopy. Video cross correlation method BOS, brightness subtraction and 1-dimensional image contraction were used for data evaluation. Results gained provided information on ignition region, flame head jet velocity, flame contours, pressure wave propagation, reacting species and temperatures. On burst of the rupture disc, the combustion of the jet starts close to the nozzle at the boundary layer to the surrounding air. Combustion velocity decelerated in correlation to an approximated drag force of constant value which was obtained by analysing the head velocity. The burning at the outer jet layer develops to an explosion converting to a nearly spherical volume at the jet head; the movement of the centroid is nearly unchanged and follows the jet front in parallel. The progress of the nearly spherical explosion could be evaluated by assuming an averaged flame ball radius. An apparent flame velocity could be derived to be about 20 m/s. It seems to increase slightly on the pressure in the tank or the related initial jet momentum. Self-initiation is nearly always achieved especially induced the interaction of shock waves and their reflections from the orifice. The combustion process is composed of shell combustion of the jet cone at the bases with a superimposed explosion of the decelerating jet head volume.     

In-situ diffraction techniques for studying hydrogen storage materials under high hydrogen pressure

Diffraction-based methods offer unique advantages for elucidating the pathways by which materials absorb and desorb hydrogen, especially when a phase change or the formation of new compounds is involved. In this case, the hydriding reaction may be followed via the changing crystallography of the phases involved in response to a change in temperature or hydrogen pressure. By using a fast diffractometer, the reaction kinetics may also be correlated to environmental conditions and the degree of completion of the reaction. In this paper we consider and model quantitatively the essential elements of a successful in-situ diffraction experiment with neutrons or X-rays under hydrogen pressures up to several kilobars: a gas manifold to accurately measure hydrogen uptake; a pressure cell designed for maximum detected intensity; means to exclude scattering arising in the cell as much as possible; methodology to correct for attenuation and subtract background intensity from the cell and environment.     

Failure pressure analysis of hydrogen storage pipeline under low temperature and high pressure

Low temperature and high pressure line pipes are widely used in hydrogen storage, air separation plant, liquefied natural gas (LNG) transportation etc. The material properties of pipes at low temperature are different from those at room temperature. If the medium in the pipe is corrosive, it will cause the pipe wall thickness to decrease. However, the failure pressure of the corroded hydrogen storage pipeline at extremely low temperature is lacking of adequate understanding. In this paper, we provided a novel failure pressure equation of the mild steel line pipe with corrosion defects at extremely low temperature. Firstly, a mechanical model of the line pipe with corrosion defects is established. And then, an analytical solution of the mechanical model is obtained based on elastic theory. Next, a failure pressure equation of the corroded hydrogen storage pipeline at extremely low temperature is developed. In the end, the accuracy of the failure pressure equation is verified by comparing with finite element method (FEM). The results suggest that the calculated value of the failure pressure equation is consistent with that of FEM. This paper provides a theoretical basis for the safety assessment of low temperature hydrogen storage pipeline. The new equation presented in this paper can provide useful guidance for the design of low temperature and high pressure pipelines.     

Analysis of millisecond collision of composite high pressure hydrogen storage cylinder

For vehicle-mounted high-pressure hydrogen storage cylinders, impact resistance is an important indicator. This work aims at building a model of 70 MPa composite fully wound Ⅳ cylinder around T800 carbon fiber material, investigating the law of transient changes in the body of the bottle under different velocity impacts and the source of risk of bursting. Through millisecond impact analysis, the energy transfer path and transformation trend inside the cylinder are obtained. Meanwhile, it was found that there was a clear pattern of positive correlation between the tensile and compressive stresses generated by the difference between the internal pressure of the bottle and the impact pressure. The final results show that after the impact, the failure occurred firstly at the inner wall of the fiber corresponding to the impact point, and the fiber damage spreads in all directions. The thickness of the failure pavement increases from the inside to the outside.     

Study on real-gas equations of high pressure hydrogen

High pressure hydrogen storage has become an important transportation channel in areas of new energy development and utilization. Actual hydrogen demonstrations require the exploration of the physical and chemical properties in detail before the practical employment, which is completely different from the ideal gas under high pressure conditions. However, the existing real-gas state equations are not easy to use in calculation of high pressure hydrogen due to its complex behavior, and may lead to an unacceptable error. In this paper, a real-gas state equation of hydrogen in a simplified form is proposed. Compared with the NIST datum, the results obtained from this equation have a maximum error 1.1% and 3.8% respectively within the temperature ranges of 253 K < T< 393 K and 173 K < T< 393 K. Also, the proposed equation exhibits higher precision for the state parameters of hydrogen than existing models. Based on the real-gas state equation of hydrogen, formulas of thermodynamic properties which are necessary for solving the hydraulic and thermal aspects of gas transfer are also proposed.     

Transient supersonic release of hydrogen from a high pressure vessel: A computational analysis

Understanding the characteristics of a hydrogen gas jet exiting from a compressed vessel during vessel rupture or venting is crucial for determining safety requirements for distribution and use of hydrogen. Such jets can undergo several flow regimes during venting, from initial supersonic flow, to transonic, to subsonic flow regimes as the pressure in the vessel decreases. A bow shock wave is a characteristic flow structure during the initial stage of the jet development, and this paper focuses on the development of the bow shock wave and the jet structure behind it. The transient behaviour of an impulsively initiated jet is investigated using unsteady, compressible flow simulations. Both the cases of a hydrogen jet exiting into quiescent hydrogen and of a hydrogen jet exiting into air are presented. The gases are considered to be ideal, and the computational domain is axisymmetric. The jet structure, including the shock wave and flow separation due to an adverse pressure gradient at the nozzle is investigated with a focus on the differences between the single- and multi-component flow scenarios.     

Exergetic sustainability indicators for a high pressure hydrogen production and storage system

This study examines the exergetic sustainability effect of PEM electrolyzer (PEME) integrated high pressure hydrogen gas storage system whose capacity is 3 kg/h. For this purpose, the indicators, previously used in the literature, are taken into account and their variations are parametrically studied as a function of the PEME operating pressure and storage pressure by considering i) PEME operating temperature at 70 °C, ii) PEME operating pressures at 10, 30, 50 and 100 bar, iii) hydrogen gas flow rate at 3 kg/h and iv) storage pressure between 200 and 900 bar. Consequently, the results from the parametric investigation indicate that, with the ascent of storage pressure from 200 to 900 bar at a constant PEME operating pressure (=50 bar), exergetic efficiency changes decreasingly between 0.612 and 0.607 while exergetic sustainability between 1.575 and 1.545. However, it is estimated that waste exergy ratio changes increasingly between 0.388 and 0.393 while environmental effect factor between 0.635 and 0.647. Additionally, it is said that the higher PEME outlet pressure causes the higher exergetic sustainability index, the lower environmental effect factor, the lower waste exergy output, the higher exergetic efficiency. However, the higher storage pressure causes the lower exergetic efficiency, the higher waste exergy output, the higher environmental effect factor and the lower exergetic sustainability index. Thus, it is recommended that this type of the system should be operated at higher PEME outlet pressure, and at an optimum hydrogen storage pressure.     

Stresses controllable analysis and optimal design of unique high pressure vessel applied in hydrogen charge station

High pressure hydrogen storage vessels are the key equipment in hydrogen charge stations. Hydrogen environment embrittlement (HEE) is always the associated problem that is inescapable and difficult to be solved completely. In order to decrease the harmfulness of HEE, a unique flat steel ribbon wound pressure vessel (FSRWPV) is designed, whose inner shell material is austenitic stainless steels 0Cr18Ni9 (304) and the steel ribbon material is 16MnR (SA516Gr70). The residual stresses in FSRWPV are analyzed and a stress controlling model is put forward. Through this model, the stress distribution in the FSRWPV wall can be controlled by adjusting the pretension in flat steel ribbons. After optimal designing, the stresses in flat steel ribbon layers are uniform, and that in the inner shell is low or negative. This kind of stress distribution can effectively prevent HEE and stress corrosion cracking (SCC), therefore the FSRWPV has good properties of bearing HEE and SCC. Furthermore, as flat steel ribbon layers are a discrete structure, the online monitoring of FSRWPVs can be conveniently realized, so they have performance of “leak only no bursting”. At the end, an applied example of high pressure hydrogen FSRWPV is given.