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1.
Huijun Wu Shengwei Wang Dongsheng Zhu Yunfei Ding 《International Journal of Heat and Mass Transfer》2009,52(21-22):5262-5265
A family of composite sorbents has been acknowledged as promising thermal storage materials for low grade thermal energy storage owing to its high specific storage capacity and low regenerating temperature. This paper reports a simplified numerical model aiming to determine the dynamic characteristics of the composite sorbents and evaluate the specific capacity and COP of the open-type thermal energy storage system. The computational results were validated with the experimental measurements carried out on an open-type thermal energy storage set-up filled with composite sorbents. By using the simplified numerical model, the dynamic characteristics of the composite sorbents in the thermal energy storage process were determined. The effects of the composite sorbents and the operating parameters on thermal energy storage system performance were also evaluated. 相似文献
2.
A family of composite sorbents was prepared by impregnating silica gel in the solution of the hygroscopic salt CaCl2 for solar heat storage. The characteristics of water adsorbed on the composite sorbents prepared under different impregnating conditions were measured by a micromeritics gas adsorption analyzer, a Calvet-type microcalorimeter and an open-type gravimetric method. From the results of these dynamic sorption measurements, the effects of impregnating variables on the characteristics of water adsorbed on the composite sorbents were evaluated. The composite sorbents prepared under different impregnating conditions were also tested on an open-type sorption storage system. The composite sorbent prepared by impregnating in the CaCl2 solution of 30% showed a high and stable storage capacity of 1020 J g−1 at the charging temperature of about 90 °C. This study demonstrates a great potential in controlling the sorption characteristics as well as the storage properties of the composite sorbents by optimizing the impregnating variables to meet the specific demands of solar heat storage. 相似文献
3.
《International Journal of Hydrogen Energy》2022,47(91):38862-38883
Composite hydrogen storage vessels have been increasingly applied to hydrogen fuel cell vehicles. This review focuses on optimization design, failure analysis and nondestructive testing for enhancing the safety of composites hydrogen storage vessels in service. The optimization designs of the composite vessel components help to improve the durability and strength of composite vessels subjected to burst pressure and fatigue loads. In complex service environments, composite vessels may suffer from various failure forms (burst failure, fatigue failure and impact failure) which involve different damage processes and influence factors. More importantly, this review discusses the applications of acoustic emission, digital image correlation, optical fiber in studying the residual performance (burst pressure and fatigue life) and damage modes of the composite vessel. It is expected that the combination of nondestructive testing techniques plays an increasingly important role in developing the composite vessel for structural health monitoring. 相似文献
4.
Recent progress and prospective of medium and high temperatures thermal energy storage materials
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开发中高温储热材料及其制备方法是储热技术发展的关键之一.本文结合中高温储热材料的分类,特点,应用及存在的问题对中高温储热材料的研究进展进行了综述,主要包括显热储热材料,热化学储热材料以及潜热储热材料.探讨了复合结构储热材料及其制备工艺,进一步介绍了其最新研究进展,并对中高温储热材料的下一步研究进行了展望,提出开发高性能纳微复合结构储热材料是未来研究的重点. 相似文献
5.
为研究硅胶在复合LiCl之后用于储热装置的性能,以4种不同浓度的LiCl溶液浸渍硅胶而制成复合吸附剂,对这4种复合吸附剂以及原硅胶的物理性质及储热性能进行测试分析。结果表明:LiCl使硅胶的比表面积等参数发生变化。复合吸附剂的渗透率在储热装置的推荐值以上,在吸附量、吸附热以及储热密度等参数上相对于硅胶均有提升,适合应用于热能储存。 相似文献
6.
Preparation of capric acid/halloysite nanotube composite as form-stable phase change material for thermal energy storage 总被引:2,自引:0,他引:2
Dandan MeiBing Zhang Ruichao LiuYatao Zhang Jindun Liu 《Solar Energy Materials & Solar Cells》2011,95(10):2772-2777
A novel form-stable composite as phase change material (PCM) for thermal energy storage was prepared by absorbing capric acid (CA) into halloysite nanotube (HNT). The composite PCM was characterized by TEM, FT-IR and DSC analysis techniques. The composite can contain capric acid as high as 60 wt% and maintain its original shape perfectly without any CA leakage after subjected to 50 melt-freeze cycles. The melting temperature and latent heat of composite (CA/HNT: 60/40 wt%) were determined as 29.34 °C and 75.52 J/g by DSC. Graphite (G) was added into the composite to improve thermal storage performance and the thermal storage and release rates were increased by 1.8 times and 1.7 times compared with the composite without graphite, respectively. Due to its high adsorption capacity of CA, high heat storage capacity, good thermal stability, low cost and simple preparation method, the composite can be considered as cost-effective latent heat storage material for practical applications such as solar energy storage, building energy conservation and agricultural greenhouse in the near future. 相似文献
7.
《International Journal of Hydrogen Energy》2019,44(45):24849-24855
Reduced graphene-oxide-supported nickel (Ni@rGO) nanocomposite catalysts were synthesized, and incorporated into magnesium (Mg) hydrogen storage materials with the aim of improving the hydrogen storage properties of these materials. The experimental results revealed that the catalytic effect of the Ni@rGO nanocomposite on Mg was more effective than that of single nickel (Ni) nanoparticles or graphene. When heated at 100 °C, the Mg–Ni and Mg–Ni@rGO composites absorbed 4.70 wt% and 5.48 wt% of H2, respectively, whereas the pure Mg and Mg@rGO composite absorbed almost no hydrogen. The addition of the Ni@rGO composite as a catalyst yielded significant improvement in the hydrogen storage property of the Mg hydrogen storage materials. The apparent activation energy of the pure Mg sample (i.e., 163.9 kJ mol−1) decreased to 139.7 kJ mol−1 and 123.4 kJ mol−1, respectively, when the sample was modified with single rGO or Ni nanoparticles. Under the catalytic action of the Ni@rGO nanocomposites, the value decreased further to 103.5 kJ mol−1. The excellent hydrogen storage properties of the Mg–Ni@rGO composite were attributed to the catalytic effects of the highly surface-active Ni nanoparticles and the unique structure of the composite nanosheets. 相似文献
8.
In the present work, three fatty acid eutectics of capric acid (CA)–lauric acid (LA), capric acid–palmitic acid (PA), and capric acid–stearic acid (SA) were prepared through melt-blending followed by ultrasonication and were investigated as model phase change materials (PCMs); for comparison, the individual fatty acid of CA was also studied. The DSC measurements indicated that the phase transition temperatures of fatty acid eutectics were lower than those of individual fatty acid of CA. Thereafter, the polyamide 6 (PA6) nanofibers and PA6/EG composite nanofibers with 10 wt.% expanded graphite (EG) were prepared by electrospinning; and then composite PCMs with fatty acid eutectics absorbed in and/or supported by the overlaid mats of electrospun nanofibers (e.g., PA6 and PA6/EG) were explored for storage and retrieval of thermal energy. Influences of the EG on structural morphologies, thermal energy storage properties and thermal energy storage/retrieval rates of composite PCMs were respectively characterized by scanning electron microscopy (SEM), differential scanning calorimeter (DSC) and measurement of melting/freezing times. The results indicated that the additions of EG caused the interfaces between fatty acid eutectics and PA6 nanofibrous mats to become more illegible; increased the absorption capacity of fatty acid eutectics within nanofibrous mats. The enthalpies of melting and crystallization of composite PCMs with EG were higher than those of the corresponding composite PCMs without EG, whereas there were no appreciable changes on the phase transition temperatures. The EG improved thermal energy storage/retrieval rates of composite PCMs were also confirmed by comparing the melting/freezing times of CA/PA6/EG and CA–SA/PA6/EG with those of CA/PA6 and CA–SA/PA6, respectively. The results from the SEM observation showed that composite PCMs had no or little variations in shape and surface morphology after heating/cooling processes. 相似文献
9.
《International Journal of Hydrogen Energy》2019,44(47):25777-25799
With the development of hydrogen fuel cell vehicles, the on-board hydrogen storage technology with safety, efficiency and economy has become a fundamental part. Low cost, light weight and good safety performance are required for the on-board hydrogen storage tanks. The composite high-pressure hydrogen storage tank has been recognized as an efficient solution that could address these problems. However, the complex working environment of hydrogen-thermo-mechanism presents challenge to the failure analysis and predictive model establishment of the composite hydrogen storage tanks. The crucial parameters or indicators for tank's failure analysis include burst pressure, damage state and fatigue lifetime, etc. So this paper gives a comprehensive review on the failure behavior analysis methods and prediction models of composite high-pressure hydrogen storage tanks from the literature. First, the failure analysis methods of composite high-pressure hydrogen storage tanks are summarized. Second, the latest literature regarding failure mode predictive methods and models of type III and type IV tanks are reviewed. The different failure criteria are compared and summarized, including some new failure criteria. These criteria enable failure analysis methods to obtain the interaction information on the interaction between the microscopic and macroscopic aspects of the composite. Damage evolution model and constitutive model are summarized. The post-initial failure behavior of the composite laminates structure is simulated by the material property degradation method (MPDM), especially the continuum damage mechanics (CDM) in conjunction with commercial finite element (FE) analysis method. The process of progressive failure analysis of composite tank is summarized as a reference for subsequent failure analysis. The future work of progressive failure analysis should focus on the initial failure of the composite material and microscopic failure mechanisms. The burst, fiber damage and fatigue life are the mainly investigated failure modes for type III composite hydrogen storage tank. For Type IV, the mainly researched failure modes are the collapse and blistering of the liner, burst and damage. The different finite element analysis methods and failure predictive models were classified and summarized. Further improvements were required for the simulation models of full-scale structure of the tank in the working environment or under the complex fiber winding modes. The liner of the type IV cylinder is completely distinct from that of the type III, therefore the behavior of collapse and blistering of the liner needs to be further investigated. The factors that affect collapse and blistering should be explored. The future research need focus on controlling these factors and monitoring the effects of these factors towards structural strength. 相似文献
10.
Phase change materials (PCMs) have attracted extensively interests in solar storage. In the study, we prepared a new kind of composite PCM by impregnating paraffin (P) into halloysite nanotube. The as-prepared composite PCM was characterized by TEM, FT-IR and DSC analysis techniques. The composite can absorb paraffin as high as 65 wt.% and maintain its original shape perfectly without any paraffin leakage after subjected to 50 melt–freeze cycles. The melting temperature and latent heat of composite (P/HNT: 65/35 wt.%) were determined as 57.16 °C and 106.54 J/g by DSC. Graphite was added into the P/HNT composite to improve thermal storage performance, and the melting time and freezing time of the composite were reduced by 60.78% and 71.52% compared with the composite without graphite, respectively. Due to its high adsorption capacity, high heat storage capacity, good thermal stability and simple preparation method, the composite can be considered as cost-effective latent heat storage material for practical application. 相似文献
11.
大规模光伏电站的不断接入为电力系统的安全稳定运行带来了巨大挑战。为解决光伏电站出力不确定性所造成的功率波动问题,提高光伏电站在并网点处电压的稳定性,文章采用由蓄电池与超级电容组成的复合储能一体化控制方法,提高光伏并网点电压稳定水平。首先研究由光伏电源、复合储能构成的典型复合储能系统拓扑结构下储能双层优化控制策略;其次,在不同储能介质的荷电状态与充放电特性模型基础上,研究基于不同光伏并网点电压波动场景的多储能介质组合电压波动抑制优化控制模型及其求解算法;最后,以并网光伏电站数据为基础,建立光伏复合储能电压波动优化控制仿真模型。仿真结果及其分析表明,文章所提出的基于复合储能的并网点电压波动抑制模型能够有效提升并网点电压稳定性能。 相似文献
12.
基于熔融浸渗法和黏结封装法,以多孔基作为基体材料,分别采用无机玻璃粉与熔盐作为相变材料开展实验,探究储热样本的最佳制备工艺流程。考察了复合相变蓄热体的显微结构及物相组成特征,分析了复合相变蓄热材料的质量损失率,并对蓄热体进行蓄热性能分析及高温抗压强度测试。实验结果表明,采用黏结封装法,以氯化钠作为相变材料,加盖圆柱形三角孔蜂窝陶瓷基体作为载体,设定6.5℃/min的升温速率,烧结温度至800℃,保温30 min,可制备蓄热性能较为优异的复合相变蓄热材料。复合相变蓄热材料的蓄热密度为445.5 kJ/kg,该蓄热体在800℃条件下高温抗压强度达到75.9 MPa,具有良好的蓄热性能和力学性能。 相似文献
13.
A novel form‐stable composite as phase change material (PCM) for thermal energy storage was prepared by absorbing stearic acid (SA) into halloysite nanotube (HNT). The composite PCM was characterized by TEM, FT‐IR and DSC analysis techniques. The composite can contain SA as high as 60 wt% and maintain its original shape perfectly without any SA leakage after subjected to 50 melt–freeze cycles. The melting temperature and latent heat of composite (SA/HNT: 60/40 wt%) were determined as 53.46°C and 93.97 J g?1 by DSC. Graphite was added into the SA/HNT composite to improve thermal storage performance, and the melting time and freezing time of the composite were reduced by 65.3 and 63.9%, respectively. Because of its high adsorption capacity of SA, high heat storage capacity, good thermal stability, low cost and simple preparation method, the composite can be considered as cost‐effective latent heat storage material for practical application. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
14.
为提高Mg O/Mg(OH)2的热化学蓄/放热性能,采用焙烧法将氧化镁(Mg O)负载在纳米多孔碳(NCP)材料上制备纳米碳基氧化镁(NCP-Mg O)复合材料。研究结果表明,NCP载体使MgO在其表面形成粒径为10~30 nm大小的颗粒,复合材料NCP-MgO具有较高的导热系数,负载80%MgO后导热系数是纯MgO的2.6倍。在反应温度110℃、水蒸气压力57.8 kPa的实验工况下,发现水合速率的大幅提升是强化Mg O/Mg(OH)2蓄热性能的主要原因,在水合反应60 min和120 min时,NCP-MgO复合材料的水合转化率分别是纯MgO的2.25倍和1.6倍。在水合反应120 min后,MgO负载率为80%的NCP-MgO复合材料的蓄热密度可达1 053 kJ/kg,是纯MgO的1.4倍。该研究可为MgO/Mg(OH)2在化学蓄热系统的应用提供一定的参考。 相似文献
15.
The aim of the present paper is to report results on hydrogenation behaviour of the new composite material Mg2Ni: CNT. Admixing of carbon nanotubes (CNT) in storage material Mg2Ni leads to noticeable enhancement in desorption kinetics as well as storage capacity. We have found that the composite material Mg2Ni–2 mole% CNT is the optimum material. The Mg2Ni–CNT composite exhibits hydrogen desorption rate of 5.7 cc/g/min as against 3.0 cc/g/min for Mg2Ni alone (enhancement of ∼ 90%) and storage capacity of ∼ 4.20 wt% in contrast to ∼3.20 wt% for Mg2Ni alone (increase of ∼ 31%). Feasible mechanisms for the enhancement of hydrogen desorption kinetics and storage capacity have been put forward. 相似文献
16.
17.
将金属有机骨架MIL-101(Cr)-NH2与CaCl2通过浸渍的方法复合得到MIL-101(Cr)-NH2/CaCl2热化学蓄热复合材料。采用X射线衍射分析仪(XRD)、扫描电子显微镜(SEM)、能谱分析(EDS)、全自动比表面积及孔径分析仪以及同步热分析仪(TG-DSC)等分析了复合材料的表观形貌、盐含量、比表面积和蓄热密度等参数。结果显示,复合材料的盐含量为49%,在30℃、32%湿度下的最大吸水量为0.54 g(H2O)/g(样品),蓄热密度达到了1 204 kJ/kg,并且在经历了17次吸附-解吸循环后,其蓄热密度仅降低了6.5%,表现出优异的循环稳定性,出色的吸附性能表明这一新型复合材料在太阳能蓄热领域具有广阔的应用前景。 相似文献
18.
储能飞轮是一种机械能量储存系统,具有广阔的应用前景.飞轮能否达到设计的高转速,需要飞轮的制作与试验验证,因此飞轮制作工艺是飞轮储能技术能否得到广泛工程应用的关键问题.本文概述了国内外复合材料储能飞轮成型工艺的研究进展,总结了飞轮转子的材料,形状以及制造工艺等问题.结合理论分析与试验研究,提出面向工程应用的先进复合材料飞轮的设计方法,提高复合材料飞轮的成型工艺水平,是今后的重要工作内容. 相似文献
19.
高孔隙率泡沫金属相变材料储能、传热特性 总被引:4,自引:0,他引:4
以高孔隙率泡沫金属材料作为骨架制备而成的新型复合相变储能材料的导热系数将大大高于相变材料本身的导热系数,在储能过程中具有更好的传热效果。给出了较通用的高孔隙率泡沫金属材料等效导热系数的估算公式,并利用准稳态方法建立了复合相变材料在凝固过程的数值模型,对其凝固过程的传热特性进行了理论分析。以铝—石蜡和铜—石蜡复合材料作为研究对象。分析表明,采用复合储能材料可以使得其传热性能得到很大提高,但是也会使复合材料的储能能力有所降低。提出了一种平衡储能能力和传热性能的方法,当泡沫金属处于平衡孔隙率时,在传热性能得到极大提高的同时也使得其储能能力降低不多。同时,分析得到了外部换热环境对储能能力、传热性能以及平衡孔隙率的影响,即较大的对流换热时,若要取得适当的储能能力和传热性能,则需要较小的孔隙率。 相似文献
20.
《International Journal of Hydrogen Energy》2019,44(40):22643-22653
Composite tanks for on-board gaseous hydrogen storage is one of key parts of the hydrogen fuel cell vehicle. Regulations, codes and standards (RC & S) are conducive to overcoming technological barriers to commercialization. This paper reviews the development of RC & S on composite tanks for on-board gaseous hydrogen storage and addresses their highlights on technical requirements. First, an overview of RC & S for composite tanks is introduced. Then, a comparative study on technical requirements of RC & S including service conditions, design requirements, materials, manufacture, qualification tests and management is presented. Finally, several major differences in RC & S, i.e., tank classification in ISO 19881 and penetration test method are discussed. Some issues for further research, such as initial burst pressure, material hydrogen compatibility and periodic inspection methods are proposed. 相似文献