金属基相变材料的研究进展及应用

金属基相变材料由于具有储能密度高、热稳定性好、热导率高等优点,在潜热热能储存系统中具有极大的优势。本文回顾了金属基相变材料的发展历程,归纳了金属基相变材料的性能参数,总结了各种热物性的测量方法,探讨了金属基相变材料与容器材料的相容性问题,分析了金属基相变材料在太阳能热发电、工业余热回收和电力削峰填谷中的应用前景。金属基相变材料的高温腐蚀性是目前限制其在热控制中应用的主要因素。为了实现金属基相变材料的广泛应用,需要重点解决金属基相变材料的封装问题。     

可用于冷链物流相变材料的研究进展

简述了相变材料(PCM)的分类和特点。根据冷链物流对温度的不同要求,将可用于冷链物流相变材料分为冷藏用和冷冻用相变材料两大类。针对固-液相变材料在液态时易发生泄漏的问题,介绍了相变材料微胶囊、泡沫金属和高吸水性树脂(SAP)等相变材料载体的研究现状。分别阐述并分析了无机相变材料、有机相变材料和无机-有机相变材料的特点及其研究进展,针对不同相变材料存在的相分离、过冷、腐蚀和导热系数小等问题,介绍了相应的解决方案。最后,指出了相变材料在冷链物流领域应用中仍然存在的一些问题,展望了冷链物流用相变材料的发展方向。     

储热材料的研究进展及其应用

综述了储热材料的研究进展和实际应用.介绍了储热材料的分类以及各类材料的性能、储能机理和优缺点;介绍了一些新型的相变材料,并结合实例探讨了储热材料在太阳能利用、建筑节能等领域的应用;指出了储热材料的研究方向和未来的发展趋势.     

玻璃钢材料在风力发电领域中的应用

介绍了玻璃钢材料的特性,以及玻璃钢制品在风力发电领域常用的成型工艺;重点叙述了玻璃钢材料在风机叶片、机舱罩、整流罩及其他附件中的应用;指出了玻璃钢材料在目前风电发电领域应用存在的问题。对玻璃钢材料在风力发电领域的应用具有一定的参考意义。     

多级并联相变管壳式换热器传热性能分析

在管壳式换热器中并联填充多级相变材料或填充单相变材料,比较两种传热装置的传热性能,分析相变材料在两种换热器的换热过程中的熔化特性、换热速率。结果显示：对于相变材料三级并联填充的换热器,相变材料完全熔化时间沿换热内管（热工质流体）轴心往外逐渐增加;在所有相变材料均完成相变之前,其三级并联相变材料的熔融前沿呈曲线状;相变材料三级并联填充的换热器的最高换热速率是单相变材料填充的1.03倍;热工质流体入口温度不变时,增加热工质流体流量可以在一定限度上增加相变材料三级并联填充的换热器的换热效率;但热工质流体流量过大会在一定限度上降低相变材料三级并联填充的换热器的换热效率。     

太阳能蓄热墙相变蓄热材料的研究进展

综述了国内外关于太阳能蓄热墙相变材料的研究进展.其中包括太阳能相变材料的分类,物理、化学性质等.目前对于一些相变材料缺陷的改进方法,及相变材料在墙体中的应用.     

相变储能材料的研究和应用

相变材料的研究与开发是一个新兴的领域。本文介绍了相变材料的功能、选择方法、分类、特性、新发展,并指出了各类相变材料存在的问题以及解决的方法。评述了相变材料在太阳能、工业余热利用、电力调峰、纺织业和建筑节能等领域的应用。     

MOFs及其复合材料在锂离子电池中的应用

金属有机骨架材料(MOFs)具有高的结构稳定性、大的孔隙率、较多的活性位点以及形态各异的骨架结构和可调控的合成条件等优点,已被广泛应用于能源储存与转化的相关领域。文中介绍了MOFs材料在锂离子电池负极材料中的应用,为了增强材料的循环比容量,通过改变MOFs材料的合成条件和合成方法对材料进行改性,在不同的温度下进行高温煅烧得到多孔碳或者通过与石墨烯复合得到复合材料等方法来改变金属有机骨架材料的力学性能和化学性能。     

ASME核电材料升级浅析

本文以国内某大型装备制造企业ASME核电N、NPT、NS换证为背景,主要介绍了非核级材料(USM级)升级为核级材料的过程,以钢管及钢板举例详细描述了库存材料的调用过程,材料提货供应单(MSO)、材料试验报告(CMTR)的编制方法及在编制过程中的注意事项     

热致变色材料的分类及变色机理

介绍新型热记忆功能材料—热致变色材料的国内外研究开发进展,着重阐述热致变色材料的分类及变色机理,对热致变色材料的分类、不可逆与可逆热致变色材料的变色机理进行了详尽的论述。在热致变色材料中有机可逆热致变色材料优点众多,将是今后研究的热点方向。     

Elastic-plastic FE calculations for a fracture mechanics analysis of a weld in the ligament of a CT specimen

Results of elastic-plastic FE calculations on four plane strain models of a CT-100 specimen, (a) with a weld in the ligament, (b) of base material only, (c) of welding simulated material only and (d) of weld material only, are compared and discussed in the light of fracture mechanics aspects. Regarding the cleavage fracture regime, considerably higher crack opening stresses are obtained in the welded specimen than in the base material specimen, as soon as small-scale yielding occurs. Conservative evaluation of the crack opening stresses of the welded joint can be achieved by using the welding simulated material properties. The J-integrals determined by the energy release rate using the method of virtual crack extension are equal for the four material models up to about 200 N mm⁻¹. Above this level, the behaviour of the welded specimen and that of the base material model are still similar, while a higher force is necessary for the welding simulated material model and the weld material model to reach the same J-value as for the two others. The crack opening profile of the welded specimen is asymmetric to the fusion line which lies in the ligament. The half profile of the heat-affected zone side is comparable to that of the welding simulated material model and the half profile of the weld material side to that of the base material model. A higher maximum of the equivalent strain on the heat-affected zone side than on the weld material side may explain why cracks tend to run into the base material region of the weld under conditions of stable crack growth. General yield of the welded specimen occurs on the base material side, whereas on the weld material side only a small plastic zone is visible, comparable to that in welding simulated material at the same load.     

复合材料在输电线路的应用与建议

介绍了复合材料的定义、树脂基复合材料的应用及其成型工艺.根据复合材料优异的材料特性以及输电线路工程的特点,对复合材料在电缆线路及架空线路等输电线路工程中的应用,分别与木质电杆、钢筋混凝土电杆和钢管电杆等传统产品进行了分析与比较,并对制约复合材料在输电线路中的应用原因进行了探讨,提出了相关的对策及建议.     

A method for the transformation of creep constitutive equations

A method has been developed that allows the material constants of complex creep constitutive equations to be determined from the knowledge of the constitutive equations of a base material, and a set of normalized material property ratios. These ratios are based on the global features of creep behaviour, such as minimum creep strain rates, lifetimes and failure strains, which may be determined, or estimated, without the need for detailed records of the creep strain which are not available in many circumstances due to the expense, or difficulty, of testing. The normalized material property ratios are formed between the global features of the creep behaviour for a non-base material, for which the material constants are to be determined, and a base material, for which the constitutive equations and their constants are accurately known. It is shown how these normalized material property ratios may be combined into a mathematical function that, when minimized, yields the constitutive constants of the non-base material. The method has been developed for a set of constitutive equations which incorporates three state variables to describe the creep behaviour of a ferritic steel. Two extrapolations of these constitutive equations to different temperatures are presented as a verification of the method. As an example, the method is used to determine the constitutive equations for the Type IV material region of a ferritic steel weldment from a knowledge of the constitutive equations for the parent ferritic steel. Finally discussed are the wider uses and implications of the method.     

水泥基渗透结晶型防水材料

阐述了防水材料的发展及防水材料的性能和特点。介绍了水泥基渗透结晶型防水材料——XYPEX的工作原理以及它的性能,并以实际工程说明了XYPEX防水材料的防渗效果。     

Characterisation of mechanical behaviour and coupled electrical properties of polymer electrolyte membrane fuel cell gas diffusion layers

Local compression distribution in the gas diffusion layer (GDL) of a polymer electrolyte membrane fuel cell (PEMFC) and the associated effect on electrical material resistance are examined. For this purpose a macroscopic structural material model is developed based on the assumption of orthotropic mechanical material behaviour for the fibrous paper and non-woven GDLs. The required structural material parameters are measured using depicted measurement methods. The influence of GDL compression on electrical properties and contact effects is also determined using specially developed testing tools. All material properties are used for a coupled 2D finite element simulation approach, capturing structural as well as electrical simulation in combination. The ohmic voltage losses are evaluated assuming constant current density at the catalyst layer and results are compared to cell polarisation measurements for different materials.     

煤水混烧技术与链条炉排新材质的研究

分析了层燃锅炉煤水混烧技术的运行特点及其对炉排失效的影响,提出该技术条件下对炉排材质的要求,介绍新试验炉排的优化配方、化学成分及金相组织,试验结果表明,试验的新炉排材质从高低温机械性能到耐热性等方面均比现用炉排材质KT350-10优越。     

Thermal management of electronic components with thermal adaptation composite material

Thermal adaptation composite material is a kind of composite material with required thermal conductivity or coefficient of thermal expansion through the selection and design of its components. A kind of thermal adaptation composite material that has excellent thermal conductivity and heat storage capacity is prepared by absorbing paraffin into expanded graphite. An electronic cooling experimental system based on the thermal adaptation composite material is built. The temperature variations of the simulative chip are respectively measured in this system and the traditional cooling system to investigate the effect of the thermal adaptation composite material on electronic cooling. At the same time, the impacts of composite material dosage and combining active cooling manner on the performance of electronic cooling are also studied. The experimental results show that the apparent heat transfer coefficients of the electronic cooling experimental system are 1.25–1.30 times higher than those of the traditional cooling system. It also can be found that the dosage of composite material has positive impact on the performance of electronic cooling. By combining active cooling manner, it can compensate the deficiency of cooling capacity in phase change thermal control.     

Nonlinear dynamic response of eccentrically stiffened FGM plate using Reddy’s TSDT in thermal environment

The nonlinear dynamics of an eccentrically stiffened functionally graded material (ES-FGM) plates resting on the elastic Pasternak foundations subjected to mechanical and thermal loads is considered in this article. The plates are reinforced by outside stiffeners with temperature-dependent material properties in two cases: uniform temperature rise and through the thickness temperature gradient. Both stiffeners and plate are deformed under temperature. Using Reddy’s third-order shear deformation plate theory, stress function, Galerkin and fourth-order Runge–Kutta methods, the effects of material and geometrical properties, temperature-dependent material properties, elastic foundations, and stiffeners on the nonlinear dynamic response of the ES-FGM plate in thermal environments are studied and discussed. Some obtained results are validated by comparing with those in the literature.     

材料利用率查询对比系统的开发及应用

介绍了在利用计算机作材料定额的过程中，如何判断自己所作部件的材料定额的利用率以及和同类部件的利用率相对比，从而判断自己所作部件的材料定额利用率的高低。本系统运用Visual Basic6．0作为前端开发工具，Oracle8i作为后台数据库管理工具。本系统的应用大大提高了材料定额的准确性，并为进一步提高材料定额利用率提供了有效的数据基础。     

Identification of inelastic material parameters for modified 9Cr–1Mo steel applicable to the plastic and viscoplastic constitutive equations

In this paper, the material parameters of plastic and viscoplastic constitutive equations for modified 9Cr–1Mo steel are developed for various isothermal conditions to support inelastic analysis for a sodium-cooled fast reactor. To do this, the material parameters related with the elastoplastic behaviour are identified with uniaxial cyclic test data by performing computer simulations, which use the combined Chaboche model including the kinematic hardening rule and the isotropic softening rule. The viscous parameters are identified from uniaxial stress relaxation test data through computer simulations with the pre-determined elastoplastic material parameters. Sensitivity studies are performed for the material parameters to investigate cyclic inelastic behaviour and stress relaxation during a hold time. From the comparison between the tests and the simulations, it is expected that the identified material parameters of the plastic and viscoplastic constitutive equations can accurately express the material characteristics of modified 9Cr–1Mo steel sufficiently well to be used for inelastic analysis.