英国一公司相变材料简介-翻译件

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英文文献和中文翻译_Use of microencapsulated PCM in c

英文文献和中文翻译_Use of microencapsulated PCM in c

微囊包封相变材料在节能混凝土墙体上的应用摘要本文章研究一种在热方面使用相变材料的新型混凝土,最终目标是研发一种在建筑上能够起到节能的产品。

现在的工作是建筑两个尺寸的混凝室作为实验装置,以研究相变材料的夹杂物在26摄氏度的熔化点下的影响,混凝室是在西班牙当地建造的。

这个研究的结果表明了使用封装相变材料墙体能量的储存情况,与不用相变材料的传统混凝土相比,前者改善了热惯性,并且有较低的内部温度。

关键字:建筑,相变材料,热能量储存,节能,混凝土1、绪论热贮备是能量守恒的一个重要方面,这主要归因于热能的合理利用,对于垃圾焚烧和工业过程中产生的余热的有效利用,还有对工业废热发电和太阳能的越来越多的利用。

对太阳能的利用要求一个有效的热储存,因此,对太阳能的利用要想成功,很大程度上,依赖于能量储存的方法。

早在1980年以前,相变材料就曾经被考虑用作建筑上的热储备。

随着相变材料在石膏板、熟石膏、混凝土和其他材料墙体上的实现,热储备将会成为建筑结构的一部分甚至包括轻质建筑。

在文献中,开发和测试用来引导相变材料人造壁板和相变材料混凝土系统的模拟实验,以提高标准石膏人造壁板和混凝土块的热能储存能力,试验在峰值负载移位和太阳能利用上有特别的兴趣。

在过去20年中,一些大容量封装相变材料的窗体被用在主动或被动的太阳能利用上,包括直接获取。

然而,大多数封装商业产品的表面,在相变材料遭到太阳直接辐射熔化以后,会向建筑不恰当地释放热量。

相对地,建筑物的墙壁与天花板为建筑物每个区域的被动传热提供了大量的面积。

一些研究者针对饱和石膏人造壁板和其他使用相变材料的建筑材料做了调查,并描述了不同类型的相变材料以及它们的特性。

生产技术、热性能和已经注入相变材料的石膏人造壁板混凝土块的应用,已经在前面提到并且讨论过了。

相变材料必须被封装起来,这样就不会对结构材料的功能产生不利影响。

先前的试验使用了大容量封装或者宏封装,由于相变材料较差的传导性导致了试验的失败。

相变材料作文模板英语翻译

相变材料作文模板英语翻译

相变材料作文模板英语翻译Title: Essay Template on Phase Change Materials。

Introduction。

Phase change materials (PCMs) are a type of material that can store and release large amounts of energy when they undergo a change in their physical state, such as from solid to liquid or vice versa. They have gained significant attention in recent years due to their potential applications in various fields, including energy storage, thermal management, and temperature regulation. In this essay, we will explore the properties, applications, and future prospects of phase change materials.Properties of Phase Change Materials。

Phase change materials exhibit unique properties that make them suitable for a wide range of applications. One of the key characteristics of PCMs is their high energy storage capacity. When a PCM undergoes a phase change, it can absorb or release a large amount of energy in the form of latent heat. This property makes them ideal for use in thermal energy storage systems, where they can store excess heat or cold and release it when needed.Another important property of PCMs is their ability to maintain a constant temperature during the phase change process. This property, known as thermal inertia, allows PCMs to regulate temperature fluctuations in their surroundings, making them useful for applications such as building insulation and temperature-controlled packaging.Applications of Phase Change Materials。

相变材料——精选推荐

相变材料——精选推荐

65 相变材料在建筑结构中的应用综述文/杨丽一、相变材料(一)相变材料定义及其特点相变材料(Phase Change Materials,简称PCM)是指随温度变化而改变形态并能提供潜热的物质。

相变材料由固态变为液态或由液态变为固态的过程称为相变过程,这时相变材料将吸收或释放大量的潜热。

相变材料具有在一定温度范围内改变其物理状态的能力。

正是相变材料的这种吸热放热现象,使得相变材料成为世界各国关注的热点。

(二)相变材料类型相变材料可分为有机和无机相变材料。

亦可分为水合相变材料和蜡质相变材料。

其中无机PCM主要有结晶水合盐类、熔融盐类、金属或合金类等;有机类PCM主要包括石蜡、醋酸和其他有机物。

近年来,复合相变储能材料应运而生,它既能有效克服单一的无机物或有机物相变储能材料存在的缺点,又可以改善相变材料的应用效果,拓展其应用范围。

二、相变储能建筑材料在建筑节能领域,随着人们对居住环境的舒适度要求越来越高,建筑能耗大幅增高,造成能源消耗过快,用电量猛增。

而我国目前严重缺电,仅空调用电量2002年夏季高峰负荷就相当于2.5个三峡电站满负荷出力,空调耗电形势极其严峻。

通过向普通建筑材料中加入相变材料,可以制成具有较高热容的轻质建筑材料,称之为相变储能建筑材料。

利用相变储能建筑材料构筑建筑结构,可以减小室内温度波动,提高舒适度,使建筑采暖或空调不用或者少用能量,提高能源利用效率;可以解决热能供给和需求失衡的矛盾,使空调或采暖系统利用夜间廉价电运行,降低空调或采暖系统的运行费用。

(一)相变储能建筑材料的节能原理相变材料在建筑节能中应用的原理为:相变材料发生相变时伴随着相变热的释放与吸收,即在热转换过程中,相变材料中的冷负荷储存在蓄能结构中,随着室外温度的降低,储存的热量一部分释放到室外,从而降低了建筑冷负荷;另一部分释放到室内,增加了晚间建筑的冷负荷。

根据上述理论,以相变储能结构为例,将相变材料应用到现有的建筑中,可以大大增加建筑结构的储热能力,使用少量的材料就可以储存大量的热量。

相变材料在建筑节能领域的潜力

相变材料在建筑节能领域的潜力

相变材料在建筑节能领域的潜力随着太阳缓缓升起,令人惊诧的一幕上演了:在美国西雅图华盛顿大学的校园内,一栋沐浴在晨光下的新建大楼逐渐开始融化。

不过这可不是什么设计上的缺陷,而是一种特殊的材料——相变材料(PCM)玩的变身小把戏。

其目的很简单,就是要帮助建筑物节能。

据英国媒体近日报道,这栋建筑的墙壁和天花板采用了一种特制的凝胶材料,当夜幕降临时,凝胶变成固体;而当白天到节能来,温度升高,凝胶便会融化。

这种材料在固态和液态之间的转变就是所谓的相变。

凝胶的这一特性可以帮助减少楼内办公室降温所需的能源消耗。

这栋在建大楼是华盛顿大学分子工程系的办公用楼,预计到本月底,98%的工程就可完工。

投入使用后,师生们就能体验一把高科技的妙处。

当然,并不是所有的相变材料都需要这么高科技。

在日常生活中接触最为频繁的冰节能环保也是相变材料的一种,冷冻和冷藏食物都离不开它。

随着材料科学的飞速进步以及能源成本的大幅提升,科学家也在加紧研发可在不同温度下工作的相变材料,用于制冷、保温和储能领域。

相变材料之所以在节能领域别具吸引力,就在于它可通过吸收或释放大量能源来保持近乎恒温:当材料融化时,需要吸收能量来打破其原子间的分子键;而当材料固化时,分子键的形成又可以释放能量。

华盛顿大学的这栋建筑所使用的凝胶是一种从植物油中提取的生物相变材料。

每天晚上窗户自动打开,室外的寒冷空气涌入,凝胶就会变成固体,待到第二天融化时又能从周围环境吸收热量。

这个原理与使用厚的混凝土或土坯墙来降低建筑物的室内温度波动类似,但凝胶的用量却相对要少得多。

制造这种凝胶的相变能源解决方案公司创办人彼得·霍瓦特说:“的生物相变材料厚度只有1.25厘米,但作为一种热质来说,却能与厚度达25厘米的混凝土媲美。

”市场调研机构勒克斯研究公司最近发布的一项报告预测,到2020年,相变材料在建筑行业的使用将从目前的年销售额近乎于零增长到1.3亿美元。

与此同时,很多其他的相变材料应用也不断涌现。

相变材料技术背景

相变材料技术背景

相变材料技术背景相变材料是一种具有特殊性质的材料,其在温度或压力变化时可以发生物理性质的改变。

这种材料可以从一个固态相转变为另一个固态相,或者从一个液态相转变为另一个液态相,甚至可以发生气态相的转变。

相变材料具有许多独特的性质和应用领域。

1. 相变材料的分类相变材料可以根据其结构和性质进行分类。

常见的分类方法包括根据固-固、液-液、液-气相变等。

1.1 固-固相变在固-固相变中,相变材料会在温度或压力发生改变时从一种晶体结构转变为另一种晶体结构。

这种类型的相变被广泛应用于记忆合金、形状记忆聚合物等领域。

1.2 液-液相变液-液相变是指在温度或压力改变下,物质从一种液态形式转化为另一种液态形式。

这种类型的相变被广泛应用于药物传递系统、生物医学器械等领域。

1.3 液-气相变液-气相变是指物质从液态转变为气态。

这种类型的相变在蒸发、干燥和制冷等领域有着广泛的应用。

2. 相变材料的原理相变材料的相变过程是由于其内部结构发生了改变。

在相变材料中,原子或分子之间的排列方式会发生改变,从而导致材料的性质发生明显的转变。

2.1 固-固相变原理在固-固相变中,晶体结构的改变是由于晶格中原子或分子之间的排列方式发生了改变。

这种改变可以通过温度或压力的调节来实现。

2.2 液-液相变原理在液-液相变中,物质分子之间的排列方式和结构会发生改变。

这种改变可以通过调节温度或压力来实现。

2.3 液-气相变原理在液-气相变中,物质从液态转化为气态是由于分子之间的吸引力减弱而导致分子离开液体表面进入气体状态。

3. 相变材料的应用相变材料由于其独特的性质,在许多领域都有广泛的应用。

3.1 温度控制和调节相变材料可以通过调节温度来实现对环境温度的控制和调节。

相变材料可以用于智能窗户、智能衣物等产品中,通过吸收或释放热量来调节室内温度。

3.2 能量储存与释放相变材料具有高储能密度和高效率的特点,可以用于能量储存与释放。

相变材料可以应用于太阳能热储系统、电池等领域,实现能源的高效利用。

相变储能建筑材料

相变储能建筑材料

相变储能建筑材料摘要:本文对相变储能材料,相变材料的原理、分类和应用情况进行了简要介绍。

并综述了相变储能建筑材料的国外的研究状况,相变储能材料与建筑材料基体结合的方法,着重介绍了相变储能材料在建筑中的应用,展望了相变储能建筑材料的发展前景。

关键词:相变储能建筑Phase Change Power Storage Building MaterialAbstract: In this paper, the principle, classification and application of phase change materials are briefly introduced. And it gives an overview of the phase change energy storage to building materials at home and abroad research condition, phase change energy storage materials and building materials matrix binding method, and then it emphatically introduces the phase-change energy materials in construction applications. Finally, this paper introduces the development prospect of phase change energy storage building materials in detail.Keywords: Phase transition; Energy storage; Architecture.目录摘要:1关键词1前言31相变节能材料概述31.1 相变材料定义及原理31.2相变材料的分类41.3 相变节能材料的应用51.3.1 在太阳能供暖系统上的应用51.3.2 在工业加热过程的应用51.3.3 在纺织行业中的应用61.3. 4 在建筑领域的应用62 相变储能建筑材料73 相变储能材料与建筑材料基体结合的方法83.1 PCM封装技术概述93.2 封装法的制备工艺93.3 封装法的不足之处104 PCM在建筑节能中的应用104.1 相变储能墙板104.1.1 相变储能石膏板114.1.2 相变储能混凝土114.1.3 保温隔热材料114.2 相变涂料124.3 相变蓄热地板125 展望13结语错误!未定义书签。

复合相变材料 英语

复合相变材料 英语

复合相变材料英语IntroductionWith the advancement of technology, material science has become a crucial field of research. One of the most exciting fields in material science is the development of composite phase change materials. These materials have a wide range of applications, from energy storage to data storage.What are composite phase change materials?Composite phase change materials (CPCMs) are materials comprised of a base material incorporated with a phase change material (PCM). The base material is usually a support material, which provides structural support to the phase change material. The phase change material usually has higher thermal conductivity than the support material. This is because the phase change material is responsible forabsorbing or releasing thermal energy during a thermal cycle.What are the advantages of CPCMs?1. High thermal energy storageComposite phase change materials have high thermal storage capacity. This makes them useful for applications thatrequire energy storage.2. VersatilityCPCMs can be designed for a wide range of applications, they can be formed into different shapes and sizes.3. Long life spanUnlike traditional storage materials like lead-acid batteries, CPCMs have a long lifespan.Applications of CPCMs1. Thermal Energy StorageCPCMs can be used in renewable energy systems to store and regulate energy. They can absorb and release thermal energy to maintain a consistent thermal environment for a longer time.2. Thermal ManagementCPCMs can be used in electronic devices like computers and smartphones to dissipate heat generated by the components. By absorbing the excess heat, they keep the device cool, preventing damage to the components.3. Data StorageCPCMs can be used for data storage because they can store thermal energy for a long time. This means that the data can be stored for a longer time without being lost.ConclusionComposite phase change materials have a wide range of applications in technology, ranging from energy storage to data storage. The use of CPCMs can help reduce energy consumption, increase the lifespan of electronic devices, and preserve data for a longer time. Their versatility makes them suitable for a wide range of applications, and their high thermal energy storage capacity is a significant advantage over traditional storage materials.。

相变材料

相变材料

相变材料(Phase Change Materials,简称PCM。

所谓相变储能是指物质在相变化过程中吸收或释放能量.正是这一特性构成了相变储能材料具有广泛应用的理论基础。

相变材料从液态向固态转变时,要经历物理状态的变化。

在这两种相变过程中,材料要从环境中吸热,反之,向环境放热。

在物理状态发生变化时可储存或释放的能量称为相变热,发生相变的温度范围很窄。

物理状态发生变化时,材料自身的温度在相变完成前几乎维持不变。

大量相变热转移到环境中时,产生了一个宽的温度平台。

相变材的出现,体现了恒温时间的延长,并可与显热和绝缘材料在热循环时,储存或释放显热。

其原理是:相变材料在热量的传输过程中将能量储存起来,就像热阻一样将可以延长能量传输时间,使温度梯度减小。

由于相变材料具有在相变过程中将热量以潜热的形式储存于自身或释放给环境的性能,因而通过恰当的设计将相变材料引入建筑围护结构中,可以使室外温度和热流波动的影响被削弱。

把室内温度控制在舒适的范围内。

此外,使用相变材料还有以下优点:其一,相变过程一般是等温或近似等温的过程,这种特性有利于把温度变化维持在较小的范围内,使人体感到舒适;其二,相变材料有很高的相变潜热,少量的材料可以储存大量的热量,与显热储热材料(如混凝土、砖等)相比,可以大大降低对建筑物结构的要求,从而使建筑物采用更加灵活的结构形式。

《相变蓄能建筑材料的研究》简介能源的可持续发展是当今世界的一大难题。

解决该难题的基本途径有两个一是依靠科技进步,发明或者发现当前能源的替代品,二是研究新型节能技术,减少能源消耗。

在开发新能源方面,太阳能的开发利用受到很大的重视。

太阳能几乎是取之不尽,用之不竭的清洁能源。

世界能源专家认为,太阳能将是本世纪的主要能源。

然而在太阳能利用方面存在一个突出的问题一太阳能的间断性,这跟昼夜交替以及天气情况有关。

因此,迫切需要一种材料能存储太阳能,使之成为一种能连续使用的能源。

在节能方面,余热或者废热的回收过程中也涉及到能量的存储问题,需要用到储能材料。

相变材料的用途

相变材料的用途

Phase Change Material PCM Applications(相变材料的用途)1. Telecom Shelters:(电信保护材料)电信材料保护层是隔热的绝缘的空调装置围挡,覆盖着移动通信的核心部位和无线电收发器的站点,以及电池。

电信保护材料对温度时非常敏感的,周围环紧通常都要低于-35摄氏度。

在不发达国家,经常发生能量削减核单相变,迫使供应商安装柴油发动机来支持空调的运行,以防能量削减核单相变。

在电信保护中使用相变材料可以吸收热量避免不能获得能量,或减少使用DG装置。

当能量源可以满足条件时,相变材料可以重新充满能量。

因为相变材料利用便宜的能源储存能量,当便宜的能源不可用时,相变材料再释放能量,这样可以节省柴油消耗成本。

2. Transportation:(交通运输过程中的保护)易腐食品,医药品,各种电子(变压器)和化学品(炸药)等需要使用冷冻汽车运输。

冷冻汽车是非常昂贵的,因为是用柴油操作的。

柴油耗能的成本是日常用电耗能的6倍。

相变材料相对而言更节能省钱。

3. Automobiles(汽车中的应用)相变材料已经作为备选设备被利用到了BMW5系列汽车的电池装置中。

原理非常简单,当发动机运行时蓄能材料被连接到散热器上吸收储存多余的热量。

这些热量可以在下次冷启动发动机是使用,发动机内部也可以平稳运行。

因为电池的良好绝缘性,在外界温度是-20摄氏度时它可以保证2天的能耗量。

相变材料也可以使用到汽车的尾气排放管道中。

4. House heating, warm water:(房间蓄热,以及加热水)太阳能不是时时都能可被利用的,同时太阳能热水器是通过介质来加热水的。

应用相变材料的系统可以提供如下好处:较小的体积,更高的效率,更好控制水温。

5. Construction materials:(建筑材料)房间环境变化较小的话更适合居住。

厚墙壁的房子居住起来更加舒服,冬暖夏凉。

为了达到这种舒适度,人们也可以在建筑材料中混入相变材料,如此以来实现跟厚墙壁一样的效果。

相变材料英文文献

相变材料英文文献

P roc edia Materials Sc ienc e 4( 2014 )389 – 394Available online at ScienceDirect2211-8128 © 2014 Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license(/licenses/by-nc-nd/3.0/).Peer-review under responsibility of Scientific Committee of North Carolina State University doi: 10.1016/j.mspro.2014.07.579390J ianqing Chen et al. / P rocedia Materials Science 4( 2014 )389 – 394energy), thermal energy storage techniques have been paid great attention (Zalba et al. (2003) and Agyenim et al. (2010)). Latent heat storage using phase-change-materials (PCMs) is particularly attractive, since it provides benefits include reduction in temperature variability (thermal inertia) and high thermal energy storage density (Hoshi et al. (2005), Tian and Zhao (2013)).Various PCMs are generally divided into two main groups from their compositions (i.e. organic and inorganic PCMs) or two categories from their melting points (i.e. high-temperature PCMs above 200 °C and low-temperature one below 200 °C). The high-temperature PCMs can be used in solar power plants, while the low-temperature PCMs are mainly used in waste heat recovery systems and buildings. Organic substances exhibit desirable properties at low temperature applications, such as limited supercooling, no phase segregation and non-corrosion. I norganic PCMs have large latent heat and can be used in high temperature energy storage. But both of organic and inorganic PCMs present a low thermal conductivity (Zalba et al. (2003), Olives and Mauran (2001)).I n order to offset the heat storage/extraction rate during melting/solidification cycles, extensive investigations have been carried out to improve the thermal response of PCMs through adding various high thermal conductivity materials (Li et al. (2008)). The methods include dispersing high conductivity particles or fibers into PCMs, impregnating a porous metallic (or graphite) matrix with PCMs.Metal foam is a cellular structure consisting of a solid metal, containing a large volume fraction of gas-filled pores. The pores can be sealed (closed-cell foam) or form an interconnected network (open-cell foam). Due to the high surface-area to volume ratio and strong mixing capability, high porosity open-cell light-metallic foams have emerged as one of the most promising emerging materials for thermal energy storage (Cui et al. (2010), Hong and Herling (2006), and Bugaje (1997)).2.PCMs Embedded with Metal FoamI n many applications, thermal energy storage is required to receive, store and subsequently release heat. The major disadvantage of PCMs is their low thermal conductivities, which dramatically slows the phase change process and causes a wide temperature distribution within PCMs. Metal foams presents an order of magnitude higher thermal conductivity than PCMs. At the same time the random internal structure and high porosity of metal foam can enhance and accelerate the phase change process without significantly reducing PCMs’ heat storage capacity. The distribution of foam ligaments in PCMs makes the melting and solidification processes more uniform.There are many kinds of metal foams have been used in phase change materials, such as aluminum foam (Bauer and Wirtz (2000), Chintakrinda et al. (2011), Tong et al. (1995), Jiang et al. (2012)), copper foam (Chi et al. (2011), Sheng et al. (2013), Zhang and Yu (2007), and Cui (2012)) and Nickel foam (Shiina (2006), Weiqiang et al (2009), Xiao, (2013)).2.1.PCMs Embedded with Aluminum FoamBauer and Wirtz (2000) developed a plate like structure thermal energy storage composite consisting of a central core of foamed aluminum foam packed with PCM to store heat during peak power operation of variable power dissipating devices. Tong et al. (1995) inserted a matrix of continuously connected aluminum foam into phase change material (water) and investigated the solidification heat transfer of the water. Results show inserting metal-matrix into water provides a very effective way to enhance the solidification heat transfer.Jiang et al. (2012) prepared a shape-stabilized PCMs using bulk porous Al foams impregnated with organic PCMs (paraffin and stearic acid). The thermal-/dynamic-mechanical properties of the shape-stabilized PCMs were studied. The filling fraction of PCMs was approximately more than 80%, the latent value of the paraffin/Al foam and stearic acid/Al foam composite is 72.9kJ/kg and 66.7kJ/kg.2.2.PCMs Embedded with Copper FoamChi et al. (2011) made a new type of high efficiency energy storage devices consisted of cooper foam and water. The cold charging process of the new type energy storage devices was approved to be faster and more adequate due to the embedding of copper foam.Sheng et al. (2013) prepared a salt hydrate/metal foam composite phase change material by using barium391J ianqing Chen et al. / P rocedia Materials Science 4( 2014 )389 – 394hydroxide octahydrate (Ba(OH)2·8H2O) as latent heat storage PCM and copper foams as a supporting matrix. Thermal cycling and heat transfer performance was studied. Results show that high porosity copper foam not only enhance the heat transfer rate of Ba(OH)2·8H2O but also effectively reduce the supercooling of the PCM.Zhang and Yu (2007) investigated the thermal performance of solid-liquid phase change thermal storage device with 98% pure Heneicosane (C21H44) filled in copper foam through a vacuuming procedure. Experimental results show that the thermal conductivity and performance of the thermal storage device is obviously improved using copper foam as a heat transfer enhancement.Cui (2012) prepared a composite PCMs using paraffin as phase change materials and copper foam as filled materials. The results show that copper foam can not only lead to a more uniform temperature distribution within the thermal energy storage unit, but also extensively shorten the charging time.2.3.PCMs Embedded with Nickel FoamShiina (2006) studied the application of latent heat storage technology using a composite PCM (a copper or nickel foam saturated by PCM). The results indicate that composite PCM had increased effective thermal conductivity and could augment temperature change reduction of the heat transfer fluid.In order to improve the void distribution and thermal performance of phase change thermal storage devices, Xu et al (2009) designed and manufactured a thermal storage containers embedded with nickel foam cores. Embedding nickel foam into the PCMs enhanced both the void distribution and thermal performance of solid-liquid phase change process.Xiao, (2013) prepared paraffin/nickel foam and paraffin/copper foam composite phase change materials (PCMs) using a vacuum impregnation method. Results show that the thermal conductivity of the composite PCMs were drastically enhanced, e.g., the thermal conductivity of the paraffin/nickel foam composite was nearly three times larger than that of pure paraffin.3.Properties of PCMs Embedded with Metal Foam3.1.Effective Thermal ConductivityDue to the high thermal conductivity and porous structure, embedding metal foam into PCMs can enhance the heat transfer, thus improve the effective thermal conductivity of the composite PCMs.t is very difficult to predict the thermal conductivity of the PCMs embedded with metal foam for the complicated pore structure of the metal foam. Xu et al (2009) proposed a new phase distribution model of metal foam matrix PCMs. Simplified heat transfer model with void sub model was established and the effective thermal conductivity formula was derived by the equivalent thermal resistance method.Zhang et al (2010) investigated the thermal parameters (Effective thermal conductivity, thermal diffusivity and thermal capacity) of copper-foam/paraffin with four different porosities using transient plane source (TPS) method. The test results showed that the effective thermal conductivity is obviously improved by embedding the copper foam into paraffin and it reached 25 times compared to pure paraffin.3.2.ConvectionMetal foam with high thermal conductivity is generally considered to have high potential to enhance the heat transfer performance for PCMs. In an attempt to enhance the convective thermal transport, metal foam can be used for making advanced compact heat exchangers because of the high surface area to volume ratio as well as enhanced flow mixing due to the tortuosity of the pass ways. But in the study of Tian and Zhao (2011), the natural convection in liquid region of the PCMs is suppressed by the metal foam. Buoyancy-driven velocities are too weak to produce dominant convection due to high viscosity and low thermal expansion ratio of the PCM and the large flow resistance of metal foam.392J ianqing Chen et al. / P rocedia Materials Science 4( 2014 )389 – 3944.Research Methods of Heat Transfer in PCMsIn order to study the heat transfer and thermal storage capacity of the PCMs, extensive research methods have been developed, such as experimental study, theoretical analysis and numerical simulation.4.1.Experimental MethodLafdi et al (2007) built an experimental setup to measure the temperature profiles and capture the melting evolution of the PCM (low melting temperature paraffin wax) inside aluminum foam. Effects of porosity and pore size of the aluminum foam on the heat transfer performance were studied. For the higher porosity aluminum foam the steady-state temperature was reached faster as compared to the lower porosity foam. By using bigger pore size foam, the steady-state temperature was reached faster as compared to the foams with smaller pore size.Wu and Zhao (2011) investigated heat transfer enhancement performance of metal foam (copper foam) in high temperature thermal energy storage system using NaNO3 as phase change material. Effect of natural convection on the heat transfer rate was investigated under bottom and top heating conditions. The heat transfer rate can be enhanced by copper foam to 2.1 times compare to pure NaNO3. However, in the liquid PCM, the heat transfer rate was no longer better that of the pure NaNO3 because metal foam suppressed the natural convection severely. Under the top heating condition, the heat transfer rate was enhanced by 1.2 times.Shi et al (2010) studied phase change heat transfer in ice ball with porous metal foam experimentally. The results show that porous metal foams can enhance the phase change heat transfer in ice ball, lead to starting phase change earlier and shorten the whole phase change time.4.2.Theoretical Analysis MethodKrishnan et al (2004) employed a two-temperature model to account for the local thermal non-equilibrium. Separate energy equations for the solid and fluid respectively are written and closed using a steady-state interphase heat transfer coefficient between the two phases. A general momentum equation that includes the Brikman-forchheimer extension to Darcy flow is employed. Natural convection inside the fluid was analyzed using a two-temperature formulation. Results show that local thermal equilibrium is not ensured either during the transient or at steady state in the system.Peng et al (2009) investigated the phase change heat transfer in PCM (wax) embedded in high porosity aluminum foam. A two-temperature model was established according to the difference of the heat transfer between wax and Al foam. The temperature distributions and flow fields of the PMCs were simulated by apparent heat capacity method. The results showed that the heat transfer of the PCMs in Al foam was effectively improved compared to pure PCMs without Al foam. Chen et al (2010) studied the melting process of paraffin in high porosity aluminum foam using a similar two-temperature model. The simulation results indicate that aluminum foam makes the temperature distribution of the paraffin more even. There is big temperature difference between metal frame and PCM during phase change process. Local thermal non-equilibrium is obvious. Melting speed of the paraffin increases with the decreasing of metal foam porosity.4.3.Numerical Simulation MethodBased on local thermal non-equilibrium between the metal matrix and PCMs, Gao and Chen (2012) and Zhang et al (2013) developed a Lattice Boltzmann model to characterize the melting processes and heating conduction of PCMs in metal foams and the temperature filed of metal foams framework. An equation based on density distribution function was constructed to characterize the velocity field of melt fluid. An enthalpy-based method is employed to account the phase change problem. The melting front location as the function of time and the temperature distribution in metallic framework and the PCMs is simulated by Lattice-Boltzmann model.The effects of the porosity and pore size on the melting are also investigated and discussed. The results indicate that the effects of foam porosity play important roles in the overall heat transfer. For the lower porosity foams, the melting rate is comparatively greater than the higher porosity foams, due to greater heat conduction from metal foam with high heat conductivity. The foam pore size has a limited effect on the melting rate due to two counteracting effects between393 J ianqing Chen et al. / P rocedia Materials Science 4( 2014 )389 – 394conduction and convection heat transfer. Increasing of the pore density leads to increasing conduction heat transfer, decreasing convection heat transfer and decreasing heat storage capacity. Therefore, it is suggested to consider engineering requirements to determine porosity in the design of foam metal heat storage device.A phase filed model deals with free boundary problems without tracing their positions, and therefore provides potentials of being extended to consider more complicated mechanisms: multi-dimension and volume change. Han et al (2013) established a foam-PCM phase filed model to solve the phase change problem by introducing two phase files to deal with phase change and volume change. The coupled heat transfer between PCMs and metal foams is solved based on the non-equilibrium heat transfer theory. An effectiveness map distinguishing the conditions under which incorporating metal foam into the PCMs is sensitive, lowly sensitive or irrelevant is produced to guide the metal selection and structure design of metal foams when enhancing the heat transfer of PCMs.5.SummaryIn this paper the research progress of phase change materials (PCMs) embedded with metal foam is reviewed. The conduction, convection and phase change heat transfer process in the PCMs has been extensively investigated. Embedding metal foam into PCMs is an effective method to enhance the heat transfer in the PCMs. Due to the high thermal conductivity, surface area volume ratio, porosity and complicated three dimension network, metal foam in the composite PCMs increase the effective thermal conductivity of the composite PCMs, and thus improve the uniformity of the temperature distribution in the PCMs. Generally the metal foam embedded in the PCMs suppress the natural convection and reducing the convective heat transfer performance. Metal foam structure affects the heat transfer performance of the PCMs significantly. It is suggested to consider both the effects foam porosity and pore size on conduction and convection heat transfer as well as engineering requirements to determine porosity in the design of foam metal heat storage device.AcknowledgementsThis work is supported by the Supporting Program for Science and Technology of Changzhou (Industry, Grant. No. CE20120024) and Fundamental Research Funds for Central Universities of China (No. 2009B16114).ReferencesAgyenim, F., Hewitt, N., Eames, P., and Smyth, M., 2010, A review of materials, heat transfer and phase change problem formulation for latent heat thermal energy storage systems (LHTESS), Renewable and Sustainable Energy Reviews, 14, 615-628.Akira, H., David, R.M., Antoine, B., Takeo, S.S., 2005, Screening of high melting point phase change materials (PCM) in solar thermal concentrating technology based on CLFR, Solar Energy Solar Energy, 79, 332-339.Bauer, C.A., and Wirtz, R.A., 2000, Thermal characteristics of a compact, passive thermal energy storage device, ASME Heat Transfer Div. Publ.HTD, 366, 283-289.Bugaje, M., 1997, Enhancing the thermal response of latent heat storage systems, Int. J. Energy Res., 21, 59-66.Chi, P., Xie, Y., Yu, J., and Yang, X., 2011, Experiment and analysis for cold charging process of new energy storage device, Journal of Beijing University of Aeronautics and Astronautics, 37, 1070-1075.Chintakrinda, K., Weinstein, R.D., and Fleischer, A.S., 2011, A direct comparison of three different material enhancement methods on the transient thermal response of paraffin phase change material exposed to high heat fluxes, International Journal of Thermal Sciences, 50, 39-47. Cui, H.T., 2012, Experimental investigation on the heat charging process by paraffin filled with high porosity copper foam, Appl. Therm. Eng., 39, 26-28.Gao, D., and Chen, Z., 2012, Influence of pore density on melting of phase change materials in metal foams-numerical simulation with Lattice Boltzmann method, Acta Energiae Solaris Sinica, 33, 1604-1609.Hai-ting, C., Feng-qing, L., Jin-da, Z., and Wei, L., 2010, Enhancement of high porosity metal foam to phase change energy storage, J. Hebei Univ. Sci. Technol., 31, 3-6.Han, X.X., Tian, Y., and Zhao, C.Y., 2013, An effectiveness study of enhanced heat transfer in phase change materials (PCMs), Int. J. Heat Mass Transfer, 60, 459-468.Hong, S., and Herling, D.R., 2006, Open-cell aluminum foams filled with phase change materials as compact heat sinks, Scr. Mater., 55, 887-890. Jinghua, J., Yingying, Z., Aibin, M., Donghui, Y., Fumin, L., Jianqing, C., Jun, S., Song, D., 2012, Preparation and performances of bulk porous Al foams impregnated with phase-change-materials for thermal storage, PNSC Progress in Natural Science: Materials International, 22, 440-444.Krishnan, S., Murthy, J.Y., and Garimella, S.V., 2004, A two-temperature model for the analysis of passive thermal control systems, Journal of Heat Transfer, 126, 28-37.394J ianqing Chen et al. / P rocedia Materials Science 4( 2014 )389 – 394 Lafdi, K., Mesalhy, O., and Shaikh, S., 2007, Experimental study on the influence of foam porosity and pore size on the melting of phase change materials, J. Appl. Phys., 102, 35-49.Li, K., Guo, N., and Wang, H., 2008, Progress on the Study of Improving the Phase Change Materials Conductivity, 1-6.Peng, D., Chen, Z., and Shi, M., 2009, Numerical simulations of phase change material thawing process in metallic foams, Journal of Engineering Thermophysics, 30, 1025-1028.Py, X., Olives, R., Mauran, S., 2001, Paraffin/porous-graphite-matrix composite as a high and constant power thermal storage material, International journal of heat and mass transfer., 44, 2727-2737.Sheng, Q., Xing, Y., and Wang, Z., 2013, Preparation and performance analysis of metal foam composite phase change material, Journal of Chemical Industry and Engineering, 64, 3565-3570.Shi, J., Chen, Z., and Shi, M., 2010, Experimental study on the effect of the porous metal foams in ice ball on the freezing heat transfer of fluid, Journal of Engineering Thermophysics, 31, 1395-1397.Shiina, Y., 2006, Reduction of temperature changes in heat transfer fluid by the use of latent heat storage technology, Transactions of the Atomic Energy Society of Japan, 5, 190-199.Tian, Y., and Zhao, C.Y., 2011, Natural convection investigations in porous, Phase Change Materials, 3, 769-772.Tian, Y., and Zhao, C.Y., 2013, A review of solar collectors and thermal energy storage in solar thermal applications, Appl. Energy, 104, 538-553.Tong, X., Khan, J.A., and Amin, M.R., 1995, Enhancement of solidification heat transfer by inserting metal-matrix into phase change material, 8.Weiqiang, X., Xiugan, Y., and Yuming, X., 2009, Effect of embedding nickel foam on solid-liquid phase change, Journal of Beijing University of Aeronautics and Astronautics, 35, 197-200.Wu, Z.G., and Zhao, C.Y., 2011, Experimental investigations of porous materials in high temperature thermal energy storage systems, Solar Energy, 85, 71-80.Xiao, X., Zhang, P., and Li, M., 2013, Preparation and thermal characterization of paraffin/metal foam composite phase change material, 112, 1357-1366.Xu, W., Yuan, X., and Li, Z., 2009, Study on effective thermal conductivity of metal foam matrix composite phase change materials, Journal of Functional Materials, 40, 1329-1332.Zalba, B., Marin, J. M., Cabeza, L. F., and Mehling, H., 2003, Review on thermal energy storage with phase change: Materials, heat transfer analysis and applications, Appl. Therm. Eng., 23, 251-283.Zhang, T., and Yu, J., 2007, Experiment of solid-liquid phase change in copper foam, Journal of Beijing University of Aeronautics and Astronautics, 33, 1021-1024.Zhang, T., Yu, J., and Gao, H., 2010, Measurement of thermal parameters of Copper-foam/paraffin composite PCM using transient plane source (TPS) method, Acta Energiae Solaris Sinica, 31, 604-609.Zhang, Y., Gao, D., and Chen, Z., 2013, I nfluence of porosity on melting of phase change materials in metal foams with lattice Boltzmann method, Journal of Southeast University, 43, 94-98.Zhen-qian, C., Ming-wei, G., and Ming-heng, S., 2010, Numerical simulation on phase change heat transfer of paraffin in metal foams, Journal of Thermal Science and Technology, 9, 6-11.。

相变材料的定义

相变材料的定义

相变材料的定义
嘿,朋友们!今天咱们来聊聊一个挺有意思的东西,那就是相变材料。

那什么是相变材料呢?简单来说,相变材料就是一种可以在温度变化时发生相变的物质。

这就好像是天气冷了水会变成冰,天气热了冰又会变成水,水和冰就是不同的相态。

相变材料也有类似的神奇本领哦!
相变材料的种类那可不少呢!比如说有一些有机相变材料,它们就像是一群小精灵,在温度的指挥下灵活地变换着形态。

还有无机相变材料,它们就像是可靠的大力士,稳定地发挥着作用。

相变材料的作用可大了去了!想象一下,在夏天的时候,我们都希望室内能凉快一些,要是有一种材料可以吸收热量,让室内温度不那么高,那该多好呀!相变材料就能做到这一点哦。

它在温度升高时会从一种相态变成另一种相态,同时吸收大量的热量,就像是一个超级吸热器。

等到温度降低了,它又会变回来,释放出热量。

这不就像是一个贴心的小助手,在默默地调节着温度嘛!
再想想看,在一些特殊的领域,比如航天领域,相变材料也能大显身手呢!航天器在太空中会面临极大的温差变化,有了相变材料的保驾护航,就能让航天器里的设备和人员更加安全和舒适。

这就好像是给航天器穿上了一件特殊的“保暖衣”。

相变材料在我们的日常生活中也有很多潜在的应用呢!比如说在建筑领域,把相变材料加入到建筑材料中,是不是就能让我们的房子冬暖夏凉啦?那我们不就可以省好多空调和暖气的费用了嘛!
相变材料真的是一种非常神奇又非常有潜力的东西呀!难道你不想多了解了解它吗?我觉得它的未来肯定会更加精彩,会给我们的生活带来更多的惊喜和便利呢!。

advanced materials; 相变材料 -回复

advanced materials; 相变材料 -回复

advanced materials; 相变材料-回复什么是相变材料?有哪些常见的相变材料应用?相变材料的制备方法有哪些?这些材料在未来的应用领域中有什么潜力?下面将对这些问题一一进行解答。

首先,什么是相变材料?相变材料是一类能在特定条件下发生相变的材料,其特点是在相变过程中会产生巨大的能量变化。

相变是指物质由一种物态转变为另一种物态的过程,例如固态到液态的熔化、液态到气态的汽化等。

相变材料的相变过程通常伴随着体积或密度的剧烈变化,因此它们在能量储存、传感器、温控装置等领域有广泛应用。

接下来,我们来看看一些常见的相变材料应用。

其中最常见的是用于能量存储的相变储能材料,比如用于热电子器件的相变随机存取存储器(PCRAM)和相变硬盘驱动器(PCSSD)。

这些储存设备利用相变材料的相变特性,实现了高密度、快速的数据存储和读写。

另外,相变材料还可以用于温控装置,例如温度自调节材料和温度感应器。

通过调节相变材料的温度,可以实现自动调节环境温度或监控温度变化。

相变材料的制备方法有多种途径。

最常用的方法是通过合金化或合成方法来制备相变材料。

在合金化方法中,将两种或更多种金属材料以一定比例混合,然后进行熔炼和固化,即可制得相变材料。

合成方法则是通过化学反应合成相变材料,例如通过溶剂法、沉淀法、热分解法等方法制备。

此外,还可以通过薄膜制备技术来制备相变材料,比如溅射沉积、激光熔凝等方法。

这些制备方法可以根据不同的相变材料的性质和需求来选择合适的制备工艺。

最后,让我们来探讨一下相变材料在未来的应用潜力。

随着人们对环境友好和节能减排的要求不断增加,相变材料在建筑领域的应用越来越受到关注。

例如,相变材料可以用于调节室内温度,减少对空调的依赖,从而节约能源。

此外,相变材料还可以应用于太阳能电池板、光伏发电等领域,提高能源转换效率。

在医疗领域,相变材料还可以应用于药物传递系统和可控释放器件,提高药物治疗的效果。

相变材料的研究和应用领域还在不断扩展,相信在未来会有更多的发展和突破。

相变材料作文模板英语

相变材料作文模板英语

相变材料作文模板英语英文回答:Phase Change Materials: A Novel Approach to Thermal Energy Storage。

Phase change materials (PCMs) are substances that undergo a reversible change in physical state from solid to liquid or liquid to gas, with the absorption or release of heat. This unique property makes PCMs a promising candidate for thermal energy storage applications.PCMs offer several advantages over traditional thermal storage materials such as water or concrete:High latent heat capacity: PCMs can store asignificant amount of thermal energy per unit volume, making them more efficient for energy storage.Constant temperature storage: During the phase changeprocess, PCMs maintain a constant temperature, which can be beneficial for heating or cooling applications.Compact size: PCMs are typically denser than water, allowing for smaller and more compact storage systems.Environmental friendliness: PCMs are non-toxic and environmentally friendly.Common types of PCMs include organic compounds (e.g., paraffin waxes, fatty acids), inorganic compounds (e.g., salts, metals), and eutectic mixtures (combinations of two or more PCMs). The selection of a PCM depends on the specific application, considering factors such as desired operating temperature range, thermal conductivity, and chemical stability.PCM-based thermal storage systems have variouspotential applications, including:Building heating and cooling: PCMs can be integrated into walls, ceilings, and floors to provide passive heatingor cooling, reducing energy consumption.Industrial processes: PCMs can be used to store thermal energy from industrial processes, such as waste heat from furnaces or exhaust systems, for later use.Renewable energy backup: PCMs can store thermal energy from renewable sources, such as solar or geothermal, for use when the primary source is unavailable.Transportation: PCMs can be incorporated into vehicle seats or interiors to regulate cabin temperature, improving passenger comfort.The design and implementation of PCM-based thermal storage systems require careful considerations of several factors:Integration and packaging: PCMs need to be effectively integrated into the storage system and protected from degradation or leakage.Heat transfer enhancement: Increasing the thermal conductivity of PCMs can improve heat transfer rates and system efficiency.Thermal cycling: Repeated phase changes can lead to volume changes and potential degradation of PCMs, requiring proper design and maintenance strategies.Research and development efforts are ongoing to optimize PCMs and their applications. Ongoing work focuses on improving thermal conductivity, reducing costs, and developing new PCMs with tailored properties for specific applications.中文回答:相变材料,热能储存的新颖方法。

advanced materials; 相变材料

advanced materials; 相变材料

advanced materials; 相变材料什么是相变材料?相变材料是一种能够通过温度、压力或其他外界条件的改变而发生物理性质变化的材料。

相变是指物质在温度、压力或组分等某些条件改变时,其物态发生变化的过程。

相变材料广泛应用于能量储存、传感器、高速电子器件等领域。

本文将介绍相变材料的原理、种类和应用。

在相变材料中,最为常见的是固相和液相之间的相变过程。

例如,将冰加热至0摄氏度,它将会从固态转变为液态,同时吸收了大量热量。

这被称作吸热相变,因为相变过程中吸收的热量被用于把固态的冰转变为液态的水。

相反,将水冷却至0摄氏度时,它将会从液态转变为固态,同时释放出大量热量。

这被称作放热相变,因为相变过程中释放的热量变为固态的水释放出来。

除了固态和液态之间的相变,相变材料还可以发生在其他物态之间,例如固态和气态之间的相变,以及液态和气态之间的相变。

这些相变过程都具有吸热和放热的特性,因此可以广泛应用于能量储存和传感器等领域。

相变材料具有许多独特的性质和优势,使其在各种应用中受到关注。

首先,相变材料具有高能量密度和高储能效率,可以储存大量的能量。

其次,相变材料的相变过程是可逆的,这意味着可以进行多次相变而不会损失能量。

这种可逆性使得相变材料在能量存储方面具有重要的应用前景。

此外,相变材料还具有较高的热传导率和热容量,使其在热管理领域具有重要的应用价值。

根据相变材料的性质和应用需求,可以将其分为几种不同的类型。

一种常见的相变材料是有机相变材料,包括聚合物相变材料和蜡相变材料。

这些材料具有低成本、低密度和良好的可塑性,广泛应用于温度控制、热管理和能量储存等领域。

另一种常见的相变材料是无机相变材料,包括金属相变材料和氧化物相变材料。

这些材料具有高能量密度、高热稳定性和高热导率,适用于高温应用和高速电子器件等领域。

此外,还有一些特殊类型的相变材料,如形状记忆合金和磁致相变材料,具有特殊的磁性和形状变化特性,在机械、电子和医疗领域具有广泛的应用前景。

相变材料作文模板英语版

相变材料作文模板英语版

相变材料作文模板英语版Phase Change Materials Essay Template。

Title: Phase Change Materials。

Introduction。

Introduce the concept of phase change materials (PCMs)。

Explain the importance of PCMs in various industries。

Provide a brief overview of the structure of the essay。

Body。

1. What are Phase Change Materials?Define phase change materials and their properties。

Discuss the different types of PCMs (organic, inorganic, eutectic, etc.)。

Explain how PCMs undergo phase change (solid to liquid, liquid to solid) and store/release energy in the process。

2. Applications of Phase Change Materials。

Discuss the various industries where PCMs are used (construction, textiles, electronics, etc.)。

Explain how PCMs are used for thermal energy storage in buildings and vehicles。

Highlight the role of PCMs in temperature regulation in clothing and bedding。

看看人家的科技成果转化英企研发新复合材料

看看人家的科技成果转化英企研发新复合材料

看看人家的科技成果转化:英企研发新复合材料材料牛注:有朋友曾跟小编戏谑地说,复合材料如同炒菜,增减一种菜就能换一个名出锅。

小编坚持认为每种成分都有它的作用,不过在科技成果转化方面,我们还是要学学人家Mather+Platt公司啊!据悉,英国著名的泵生产商Mather+Platt公司近日研发出了一种高分子基弹性材料,应用于泵机组的内部组件以及外罩上,可以提高泵效率、减少腐蚀,大大减少泵的维护工作。

目前这种先进的高分子材料处于研发阶段,还没有商业化。

Mather+Platt公司的经理Dave Johnson介绍道,这种先进的高分子基弹性材料,是由一位德裔的南非工业化学家研发出来的,由液体变为固体后能够形成耐磨损、耐化学腐蚀、坚硬的光滑表面。

这种环保涂料已经在62种不同的化学环境中测试过,不管是炎热、寒冷、腐蚀性、重金属、细菌、寄生虫环境,还是放射性或电气环境中,涂料的质量都没得说,甚至能抵抗酸性或腐蚀性最强的化合物,如盐酸、氢氧化钠和硫酸等。

据说这种涂料的品质十年无忧,不仅是自灭性材料(不燃烧且不助燃),而且可以不经喷砂处理直接用于已经生锈的钢结构、管道、坦克或船舶。

这简直是泵行业的福音!因为泵输送的流体的化学性质会日积月累地影响泵的寿命和效率。

泵的质量越不好,电动机负载就越大,维修就越昂贵。

在计算泵和电机的整体效率时,需要将两者的效率百分比相乘。

例如,如果一个电机的输出效率是92%,泵的效率是86%,那么整体效率为79%(0.92×0.86 = 0.79)。

我们可以看出,尽管泵或电机的效率很高,泵组件的效率总是较低的。

这种高分子基弹性材料的应用非常广,甚至可以在采矿程序中代替喷射混凝土。

“在工程实践中,用3 mm的高分子基弹性材料做衬里,性能甚至优于50mm厚的纤维增强喷射混凝土。

” 这种涂层增强了泵的寿命、减少了维修工作、提高了效率,能够实现很高的经济效益。

反观我国的科技成果转化,目前正遭遇着重重困境:一方面是大量研发成果与市场需求脱节,无法被商业化;另一方面科研与应用脱节,缺乏致力于科研成果转化的中间力量,创新成果需求方难以及时有效获取本领域技术进展信息。

相变材料简介

相变材料简介

相变材料的分类相变材料主要包括无机PCM、有机PCM和复合PCM三类。

其中,无机类PCM主要有结晶水合盐类、熔融盐类、金属或合金类等(熔融盐是盐的熔融态液体,通常说的熔融盐是指无机盐的熔融体。

)(结晶水合盐按我的理解就是含有结晶水的无机盐类)无水氯化钙(Calcium chloride anhydrous),为白色立方结晶或粉末,有强吸湿性,相对密度2.15,熔点775℃,沸点1935.5℃。

易溶于水和乙醇。

用于各种物质的干燥剂,此外还有马路防尘,土质改良剂,冷冻剂。

用于化学试剂、医药原料、食品添加剂、饲料添加剂及制造金属钙的原料。

也用于脱水剂、上桨剂、净水剂。

以下摘自“相变材料的研究与应用报告”无机类相变材料具有价格便宜、热导率较高、熔解热较大、密度大等特点,但在使用过程中具有腐蚀性,且容易发生“过冷”和“相分离”现象。

与无机类相比,有机类腐蚀性低,无“过冷”和“相分离”现象,但其密度小,导热率低。

近年来相变材料的应用主要体现在热缓冲和热储存。

两者的区别在于相变材料的导热率不同,热缓冲方面要求适当低的导热率(有机类);热储存方面需要高导热率(无机类),以便热能的迅速储存和利用。

在建筑领域,利用相变材料可以有效地推迟温度波动通过建筑物的传播,提高建筑物的热惯性。

在太阳能领域,将组合相变材料用于吸热其模型,能够减少工质温度的波动,提高吸热气的效率。

在纺织行业中,在纺织纤维中添加微胶囊相变材料可以提高服装的保温性能,用于维持服装内温度的稳定。

在军事领域,将相变材料以涂料或遮障的像是用于军事目标上,通过改变、调节相变材料的组成、含量等,使其竟可能的吸收目标放出的热量,使军事目标的温度与周围环境温度相同。

以下摘自中国相变材料应用网:应用:相变材料在制冷工程中的运用:1.水冷式中央空调系统利用相变材料的节能应用2.无制冷机空调系统3.被动制冷式住宅空调补助系统相变材料在采暖工程中的运用:1.相变材料地板采暖装置2.相变材料热水器装置3.无能耗住宅采暖系统(温差大于10°C 的地区)4.相变材料与太阳能采暖系统相变材料在通信、电子工程中的运用:1.相变材料通信用电池保护外套2.相变材料野外恒温通信信号箱3.相变材料野外无人维护通信机房4. 相变材料电子器件散热器相变材料在民用工程中的运用:1.降低建筑物能耗的相变材料室内装修材料2.能提高体育馆,剧院,礼堂和餐馆能效的相变材料座椅。

相变材料(修改后)

相变材料(修改后)
80-90
反应速率 快
反应稳定性 是
粒度可控性 易
悬浮聚合 7~75



界面聚合 15~73



原位聚合 14~67



分离回收 易 易 易 易
工业化 易 易 难 难
粒径 5微米
建筑节能 高达35%
微胶囊相变材料SEM图
微胶囊相变材料DSC图
微胶囊相变材料稳定测试图
微胶囊相变材料建筑应用 黑色曲线为添加PCM的室内温度波动
微胶囊相变材料技术产业化
(厨余垃圾生物柴油企业产业升级)
相变材料(PCMs – Phase Change Materials) 是一种在一个恒温或者近似恒温过程发生相变而能够吸收或者 释放较大能量的物质。
333kJ/kg
潜热
使液态水 升温80℃
相变材料的应用
冷链物流
• 网购生鲜食品占6.73% • 冷链是普通物流成本的1倍
产品对比
微胶囊 Farid微胶囊
相变温度 范围℃
-5~35
导热速率 W/m·K
封装率 wt.%
1
80-90
(提升5倍) (提升近1倍)
热熔 kJ/kg
80-110
定价 RMB/吨
60000 (降低近25%)
德国RUBITHERM -4~100/10-80 RT系列/PX系列[1]
BASF Miconal PCM[2]
财务预测
项目 年产量(吨) 产品销售收入/万元 总成本费用/万元 销售利润/万元 所得税(25%)/万元 税后利润/万元
第一年 1000 6000 2575 3425 856 2569
第二年 2000 12000 5063 6938 1734 5203

科学家发现一种能瞬间变成固体的液体物质

科学家发现一种能瞬间变成固体的液体物质

科学家发现一种能瞬间变成固体的液体物质时间:2018-11-29 来源:互联网
据英国每日邮报报道,目前,英国科学家最新研制一种粘性物质,只需摇动便能从液体转变为橡胶状固体,该物质潜在着广泛的应用领域。

然而科学家并不知道是何种原因导致该材料发生奇妙变化,并问询专家提供指导性解释。

据悉,这种摇动胶体是英国帝国理工学院化学工程师发现的,他们试图发现具有新属性的材料。

将两种化合物混合在一起,一种化合物包含二氧化硅,一种化学物叫做聚氧化乙烯(polyethyeleneoxide),结果发现这种具有奇特属性的胶体物质。

英国帝国理工学院工程实验室最新实验表明,一个小玻璃罐内部充满着这种稠密乳状液体物质。

当研究人员用力摇动时,液体会转变成为一种粘性固体物质,之后揉捏可形成一种类似油灰的物质,如果放置一段时间,它将转变成为液体。

研究负责人、帝国理工学院保罗-卢克哈姆(PaulLuckham)说:“意外发现是一件非常美妙的事情,尤其是在实验室获得新发现!目前我们仍在对这种特殊粘性物质进行实验,充分理解它的属性和潜能,它呈现的一些独特属性,令我们希望进行深入探索。


研究小组还未发现这种新型胶体的一种明确应用,但是他们认为它潜在具有许多用途,例如:用于制造口香糖等。

人们通过食用这种口香糖,将避免出现街道出现硬化的口香糖粘黏物,未来“胶体口香糖”变干之后可以转变成为液态,很容易从路面上清除。

这种胶体被分类为“非牛顿流体物质,它的属性可以进行控制,仅是改变混合物质,便能短时间内改变它的物理状态。

然而该胶体变得更加奇特,研究小组发现虽然胶体具备部分非牛顿流体属性,摇动之后就能改变它们,甚至停止摇动几个小时之后也会发生变化。

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1、蓄能(thermal energy storage)简述
蓄热填补了建筑用能与功能间的不匹配。

蓄能周期可根据系统需求设计,可以为一日、一周或是一个季节。

蓄能系统必定以热量形式放能,但蓄能过程可通过热量或电量形式输入。

通过蓄能调峰,可实现:
●降低运行能耗
●降低设备容量
●增强系统可调性
●增大系统安全性
●节能减排
2、相变材料介绍:
通过相变(熔化/凝固)过程,相变材料可以以潜热形式蓄存/放出大量热。

这一特点使其在蓄能领域中得到了广泛应用,可以实现在某一时段的某一过程中吸收冷量或热量,转而推移至另一时间或转移至另一地点放出。

此外,相变材料还可提供附加热阻,在控温运输等工业领域尤其有益。

有趣的是,最简单、便宜且有效的相变材料其实是水(或冰)。

然而,水的凝固点为0℃,对于绝大多数的蓄能应用并不合适。

所幸,许多其他的相变材料已经被发现,相变温度范围低至零下,高达数百摄氏度。

考虑相变温度,相变材料被划分为四类。

●低共熔物体系:盐的水溶液,相变温度在0℃以下
●水合盐:一些在凝固过程中可吸收结晶水的盐类,相变温度一般高于0℃
●有机材料:以碳、氢为主要元素的高分子聚合物,常见的如椰子油、石蜡与脂肪酸,相
变温度一般高于0℃
●固-固相变材料:此类材料在相变过层中无明显可见变化(除细微膨胀与收缩之外),因
此可免去相变材料应用中封装、防泄漏等问题

3、相变蓄能应用
3.1、在建筑领域内的应用
如图为马来西亚一零能耗建筑,夜间相变材料蓄存冷量,
我们将相变蓄冷在冷冻水系统中的应用推广至世界各地,包括位于西雅图的美国陆军总部、通往澳大利亚的高速铁
如图为墨尔本议会总部,是世界上唯一一栋达到六级能效
如图为英国威斯敏斯特大学一相变砖铺做的屋顶,夜间相
都灵附近一热电联产工厂在系统的冷、热侧皆采用相变材
在英国国家剧院的设计中,通过加入相变蓄能系统,可对电力、供冷、供热三者进行联合调节。

不仅可实现以日为
周期的调控,亦可以年为周期,调节不同季节间的负荷情
届世界杯一定程度上归功于其零能耗体。

在无赛事进行时,利用太阳能发电驱动制冷机,并将冷量存入相变材料中,在比赛时则从相
3.2、控温包装与运输
而利用相变蓄能技术则
但可满足不同的温度要
相变材
目前相变蓄能技术已在多个国家的军用医疗运输产业中
3.3、被动式供冷
℃日间承担热负荷。

机中得到应避免电子器件的温
)类似,可用于偏远地区的信号发射盒子内温度合适而无需借助于
当数据采集仪工作在高温环境中(如:熔炉、喷气式发动
3.4、太阳能供暖与热回收
通过设计合适的相变蓄能系统,可减缓热负荷波动,在相对稳定的供热需求下,供热系统工作的可靠性的此外,在一些畜牧场、酿酒厂和食品加工厂中,通过,可在无机械系统
通过浸入相变材料,太阳能集热器热水箱的蓄热能力
在冬季,太阳能集热器往往难制得热水,但可通过相变地板的形式,吸收日间多余的太阳能,在夜间放出维持室内舒适。

通过合理的循环设计,整栋建筑的热
该建筑为太阳能十项全能竞赛项目,采用了相变蓄能系统,夏季通过夜间蓄冷解决日间的冷负荷,冬季通过日间吸收太阳能蓄能解决夜间热负荷,而不再需要
4、产品开发与应用案例
参作为电子器件的隔作为太空采集样品
我们设计了车载相变蓄能系统来为司机提供舒适的驾驶℃,在夜间蓄冷,日
℃的
虽然设备外壳有一定耐燃性,但设备温度却仍旧会升小时的时间内将设备温度维持在正常水平,为救火提供时间裕量,
,为消防员以及其他工作在恶劣环境下的工含有相变材料的坐垫,为轮椅使用者设计,防止过热。

物品温度明显。

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