The imbalance of energy supply and demand and a series of environmental problems are associated with traditional energy. In order to alleviate the above concerns, renewable energy is getting more and more attention, although it has intermittent and regional characteristics, heat storage technology is the key to solve these. In this review, by comparing with sensible heat storage and chemical heat storage, it is found that phase change heat storage is importance in renewable energy utilization, because of its simple system, low price, high heat storage density, and stable heat storage temperature. Then, the application of phase change heat storage technology in different fields is discussed, including building energy saving, thermal management of electronic equipment, solar energy system and energy storage system. By investigating the literatures, it is found that the phase change heat storage technology is not only related to the phase change material, but also associates with the phase change heat storage device. Therefore, how to enhance the performance of the device is divided into two aspects in this paper: On the one hand, phase change material should be researched. It is well known that single phase change material has problems such as supercooling, low thermal conductivity, phase separation, etc. In order to solve these shortcomings, a eutectic composite phase change material has appeared by mixing two or more phase change materials. Phase separation can be inhibited by porous skeleton materials. Or package the phase change materials in different shapes and sizes; Mixing of graphite or nanoparticles helps to enhance the low thermal conductivity of phase change materials. On the other hand, the heat storage performance is improved through optimizing the phase change heat storage device. The tubular, plate and special shape phase change heat storage devices are summarized. U-shaped tube, ZZ-shaped tube, WW-shaped tube, spiral tube and other different structures of heat exchange pipes can be adopted. Cascade phase change heat storage is also used; Varies structure and number of fins on the heat transfer fluid side or the phase change material side employed, too. In addition, the application of bionic configuration principle in phase change heat storage device also been summarized. 传统能源的供能与需求不平衡以及一系列环境问题与之相关。为了缓解上述问题,可再生能源越来越受到关注,尽管它具有间歇性和区域性的特点,热能储存技术是解决这些问题的关键。在本文综述中,通过与显热储存和化学热储存进行比较,发现相变热储存对于可再生能源利用的重要性,因为其系统简单、价格低廉、热储存密度高且热储存温度稳定。然后,讨论了相变热储存技术在不同领域的应用,包括建筑节能、电子设备的热管理、太阳能系统和储能系统。通过研究文献,发现相变热储存技术不仅与相变材料有关,还与相变热储存装置有关。因此,本文将相变热储存装置性能的提升分为两个方面:一方面,应研究相变材料。 众所周知,单相变材料存在诸如过冷、热导率低、相分离等问题。为了克服这些缺点,通过混合两种或多种相变材料出现了共晶复合相变材料。通过使用多孔骨架材料可以抑制相分离。或者将相变材料制成不同的形状和尺寸;掺入石墨或纳米颗粒有助于提高相变材料的低热导率。另一方面,通过优化相变热储能装置来提高热储能性能。总结了管状、板状和特殊形状的相变热储能装置。可以采用 U 形管、 ZZ 形管、 WW 形管、螺旋管等不同结构的换热管。级联相变热储能也被使用;在热载流体侧或相变材料侧采用不同的结构和数量的翅片,也进行了总结。还总结了仿生配置原理在相变热储能装置中的应用。
1. Introduction 1. 引言
With the carbon neutrality and carbon peak goal was raised, improving energy utilization efficiency was significant for environment problems and solving energy storages [1]. The environmental problems almost associated with conventional energy, including energy extraction, processing, transportation and use. The use of renewable energy is urgent Relatively, its little pollution and environmental friendliness. But it is intermittent and has a low energy density. In order to solve these problems, considering the use of energy storage technology. 随着碳中和与碳达峰目标的提出,提高能源利用效率对于解决环境问题和能源存储问题至关重要 [1]。环境问题几乎与传统能源相关,包括能源的开采、加工、运输和使用。相对而言,可再生能源的使用迫在眉睫,其污染小且环保。但可再生能源是间歇性的,且能量密度较低。为了解决这些问题,考虑使用储能技术。
Energy storage technology has greater advantages in time and space, mainly include sensible heat storage, latent heat storage (phase change heat storage) and thermochemical heat storage. The formula (1-1) can be used to calculate the heat [2]. Sensible heat storage method is related to the specific heat capacity of the materials, the larger the specific heat, the more heat is stored. Common materials cover gravel, rock, water, pebbles, etc. [3]. Simple equipment, low price and easy availability, so it has been widely used. However, with the demand for energy increase and the improvement of energy quality requirements, sensible heat storage materials are not conducive to long-term storage and long- 能源存储技术在时间和空间上具有更大的优势,主要包括显热存储、潜热存储(相变热存储)和 thermochemical 热存储。公式(1-1)可以用来计算热量[2]。显热存储方法与材料的比热容有关,比热容越大,存储的热量越多。常用材料包括碎石、岩石、水、卵石等[3]。设备简单、价格低廉且易于获取,因此被广泛使用。然而,随着能源需求的增加和对能源质量要求的提高,显热存储材料不利于长期存储和长距离运输。
c_(p)c_{p}-the specific heat of the heat storage material, kJ//(kg*K)\mathrm{kJ} /(\mathrm{kg} \cdot \mathrm{K}); c_(p)c_{p} -储能材料的比热容, kJ//(kg*K)\mathrm{kJ} /(\mathrm{kg} \cdot \mathrm{K}) ; T_(1),T_(2)T_{1}, T_{2}-initial heating temperature, final heating temperature, K ; T_(1),T_(2)T_{1}, T_{2} -初始加热温度,最终加热温度,K;
Phase change heat storage, which store and release heat with a large amount of energy and the state also has been changed. Such as solidliquid, solid-solid, solid-gas, liquid-gas by the heat storage materials [4]. Phase change heat storage generally go through three stages, namely sensible heat stage, phase change stage and sensible heat (when the final temperature is higher than phase change temperature). Therefore, the formula (1-2) was used to calculated the heat by change progress [2]. The latent heat is about 4-15 times than the sensible heat storage [5,6][5,6]. The device is relatively simple. During the phase change the temperature is almost constant, so the volume of device can be miniaturized. Phase change materials (PCMs) include organic PCMs, inorganic PCMs and eutectic PCMs. However, due to the low thermal conductivity of organic PCMs, supercooling and corrosion of the inorganic PCMs [7], the efficiency is low, and the development also been limited. 相变热储存,储存和释放大量能量并伴随状态改变的热储存。例如,通过热储存材料实现的固液、固固、固气、液气相变[4]。相变热储存通常经历三个阶段,即显热阶段、相变阶段和显热(当最终温度高于相变温度时)。因此,使用公式(1-2)计算相变过程中的热量[2]。潜热大约是显热储存的 4-15 倍 [5,6][5,6] 。设备相对简单。在相变过程中,温度几乎保持恒定,因此设备的体积可以缩小。相变材料(PCMs)包括有机 PCMs、无机 PCMs 和共晶 PCMs。然而,由于有机 PCMs 的热导率低、无机 PCMs 的过冷和腐蚀[7],效率较低,发展也受到限制。 Q_(l)=mc_(p1)(T_(2)-T_(1))+m Delta h+mc_(p2)(T_(3)-T_(2))Q_{l}=m c_{p 1}\left(T_{2}-T_{1}\right)+m \Delta h+m c_{p 2}\left(T_{3}-T_{2}\right) c_(p1),c_(p2)c_{p 1}, c_{p 2}-the specific heat before and after the PCMs, kJ//(kg*K)\mathrm{kJ} /(\mathrm{kg} \cdot \mathrm{K}); c_(p1),c_(p2)c_{p 1}, c_{p 2} -PCMs 的比热容变化, kJ//(kg*K)\mathrm{kJ} /(\mathrm{kg} \cdot \mathrm{K}) ; T_(1),T_(2),T_(3)T_{1}, T_{2}, T_{3}-the initial temperature, the phase change temperature and the final temperature, K ; T_(1),T_(2),T_(3)T_{1}, T_{2}, T_{3} -PCMs 的初始温度、相变温度和最终温度,K ; Delta h\Delta h-the phase change enthalpy of the PCMs, kJ//kg\mathrm{kJ} / \mathrm{kg}; Delta h\Delta h -PCMs 的相变焓, kJ//kg\mathrm{kJ} / \mathrm{kg} ;
Thermochemical heat storage through reversible chemical reactions between adsorbents (such as chloride and sulfate, etc.) and adsorbed substances (such as water and ammonia, etc.) to storage heat [8]. Compare to another two heat storage methods, thermochemical heat storage has a high heat storage density and can stored in long time at ambient temperature. The heat is converted into internal energy and stored. The heat storage density is about 8-10 times that of sensible heat storage and 2 times that of phase change heat storage. The device is difficult to design because the reaction temperature is usually high [9]. The research is still in the laboratory stage. 通过吸附剂(如氯化物和硫酸盐等)与吸附物质(如水和氨等)之间的可逆化学反应来进行热化学热储存,以储存热量 [8]。与另外两种热储存方法相比,热化学热储存具有高的热储存密度,并且可以在常温下长时间储存热量。热量转化为内能并储存起来。热储存密度大约是显热储存的 8-10 倍,是相变热储存的 2 倍。由于反应温度通常较高,装置设计较为困难 [9]。目前研究仍处于实验室阶段。
According to the above introduction, compared with sensible heat storage and thermochemical heat storage, PCHS has been widely used due to the high heat storage density, simple systems and almost constant temperature during the phase change process [10]. But it is also limited by the low thermal conductivity and phase separation, the temperature distribution whether uniform in the PCHS devices as well as the thermal response. In general, PCMs can be divided into organic PCMs, inorganic PCMs and eutectic PCMs. Paraffin and fatty acids are the most common organic PCMs, and paraffin is considered as the best PCMs because of it has large phase change temperature range. Because the mixture of straight-chain alkanes in paraffin [11]. The longer the straight-chain, the higher the phase change temperature and latent heat. Organic PCMs are divided into paraffin and non-paraffin PCMs. Non-paraffin PCMs like fatty acids and alcohols [12]. Normally, the phase change temperature, as well as the thermal conductivity and the price are low. These materials without supercooling, toxicity and corrosion, there are widely used in the middle and low temperature zone. However, the flammability of organic PCMs limits their application with high temperature. Inorganic PCMs mainly include hydrated salts and metal alloy PCMs. Hydrated salt PCMs are common inorganic PCMs, they are always can be expressed in chemical expressions because them composed of salt and water. Hydrated salt PCMs adsorption/desorption of water molecules to complete the heat storage/release. Compared with organic PCMs, Hydrated salt PCMs with higher heat storage density and thermal conductivity and used in solar energy utilization and temperature control. Eutectic PCMs mainly include organic-organic, organic-inorganic and inorganic-inorganic composite PCMs, which composed by two or more kinds of organic or inorganic PCMs or their mixture. Eutectic composite PCMs can overcome the shortcomings of single materials and 根据上述介绍,与显热蓄热和化学蓄热相比,相变热储能(PCHS)由于具有高的热能存储密度、简单的系统结构以及相变过程中几乎恒定的温度,已被广泛使用 [10]。但相变热储能也受到低热导率和相分离的限制,相变热储能装置中的温度分布是否均匀以及热响应也是其局限性。一般来说,相变材料(PCMs)可以分为有机相变材料、无机相变材料和共晶相变材料。石蜡和脂肪酸是最常见的有机相变材料,而石蜡因其较大的相变温度范围被认为是最优的相变材料,因为石蜡中直链烷烃的混合物 [11]。直链越长,相变温度和潜热越高。有机相变材料分为石蜡和非石蜡相变材料。非石蜡相变材料如脂肪酸和醇 [12]。通常,相变温度、热导率和价格都较低。这些材料没有过冷、毒性小且不易腐蚀,因此在中低温区得到了广泛应用。 然而,有机相变材料的可燃性限制了其在高温环境中的应用。无机相变材料主要包括水合盐和金属合金相变材料。水合盐相变材料是常见的无机相变材料,它们总是可以用化学式来表示,因为它们由盐和水组成。水合盐相变材料通过吸附/解吸水分子来完成热储存/释放。与有机相变材料相比,水合盐相变材料具有更高的热储存密度和热导率,并被用于太阳能利用和温度控制。共晶相变材料主要包括有机-有机、有机-无机和无机-无机复合相变材料,由两种或多种有机或无机相变材料或其混合物组成。共晶复合相变材料可以克服单一材料的缺点并
be used comprehensively. For example, Sun et al. [13] developed a eutectic PCMs composed of sodium pentahydrate thiosulfate (Na_(2)S_(2)O_(3)*5H_(2)O:}\left(\mathrm{Na}_{2} \mathrm{~S}_{2} \mathrm{O}_{3} \cdot 5 \mathrm{H}_{2} \mathrm{O}\right., STP), sodium trihydrate acetate (CH_(3)COONa*3H_(2)O:}\left(\mathrm{CH}_{3} \mathrm{COONa} \cdot 3 \mathrm{H}_{2} \mathrm{O}\right., SAT ) and deionized water. The composite PCMs provided an alternative method to solve battery capacity decline in cold environment. This research was beneficial for high energy efficiency battery thermal management system, without sacrificing the power. Zhou et al. [14] aimed to develop aluminum ammonium sulfate dodecahydrate (NH_(4)Al:}\left(\mathrm{NH}_{4} \mathrm{Al}\right.(SO_(4))_(2)*12H_(2)O\left(\mathrm{SO}_{4}\right)_{2} \cdot 12 \mathrm{H}_{2} \mathrm{O}, AASD) based novel composite PCMs for thermal energy storage. A melting/solidification experiment was established to analyze the influence of various additives and thermal cycles on the heat storage/release performance of AASD based composite PCMs. Fu et al. [15] using a non-eutectic mixture comprised of NaAc*3H_(2)O\mathrm{NaAc} \cdot 3 \mathrm{H}_{2} \mathrm{O} and as PCM , and expanded graphite (EG) as supporting material, a novel composite PCM with high thermal performance used in the heat exchanger for the floor radiant heating was developed. The results showed that the mixture containing 12%12 \% glycine was favorable due to its suitable phase change temperature ( 48.62^(@)C48.62{ }^{\circ} \mathrm{C} ) and high phase change enthalpy (258.5 kJ*kg^(-1)\mathrm{kJ} \cdot \mathrm{kg}^{-1} ). Wang et al. [16] prepared graphite powder/paraffin composite PCM and graphite power/paraffin/nickel foam ternary composite PCM. Both composite PCMs can effectively control the surface temperature rise of lithium-ion battery, and heat efficiency similar, too. But the second composite PCM had better temperature homogeneity. Yang et al. [17] analyzed porosity, pore size and internal voids of copper ribs on the thermal conductivity of the copper foam/paraffin composite PCM. Results showed that increasing porosity would decrease thermal conductivity, and the internal voids of copper ribs were an important factor affecting the thermal conductivity. Kousksou et al. [18] investigated a cylindrical tank which packed with spheres having uniform sizes, paraffin as PCM. Various input temperature signals of the working fluid were tested, this result obtained for a multi-slab configuration and maximum the energy stored as possible. Kenisarin [19] was reviewed PCMs for heat storage and solar energy in the temperature range of 120^(@)C120^{\circ} \mathrm{C} to 1000^(@)C1000^{\circ} \mathrm{C}. The thermophysical properties of the salts based on fluoride, chloride and hydroxide as well as nitrate, carbonate and metal alloys were given, and the long-term properties of some materials are analyzed. Dhaidan et al. [20] summarized melting and convective heat transfer processes of PCMs in rectangular cavity, spherical capsule, tubular or cylindrical cavity and annular cavity. The constrained melting and unconstrained melting of containers were discussed. The geometric parameters of different containers and the corresponding influencing factors are also analyzed. Subsequently, he [21] further studied the solidification/freezing process of PCM in different container structures. Through the observation of the solidification/freezing process, it was found that the system was dominated by convective heat transfer in the initial stage of solidification, and gradually the heat conduction. The annular cavity had the least influence on the discharging, while the plane shape and vertical cylindrical cavity had the greatest influence on the heat release time and rate. Muthya et al. [22] objected to understand and quantify the shape stability of a composite PCM, that mixed myristyl alcohol with expanded graphite at virous loadings. Cheng et al. [23] prepared micro-PCMs with epoxy resin as the capsule shell, microcapsules were compounded with different types of epoxy resins. The results showed that by changing the micro-PCMs content in the composite PCM, the phase change enthalpy of the composite PCM also adjusted. Wang et al. [24] selected palmitic acid as PCM and ZnO//\mathrm{ZnO} / Expanded Graphite as supporting material. Analyzed with a series tests, then suggested this composite PCM has superior thermal stability and excellent potential in heat storage. Wei et al. [25] prepared Al-Si//Al2O3\mathrm{Al}-\mathrm{Si} / \mathrm{Al} 2 \mathrm{O} 3 composite PCM with controllable melting temperature. This composite PCM with great repeatable utilization performance and structural stability, was potential for concentrated solar power plants. Radouane et al. [26] simulated the thermal performance of the storage unit incorporating triple concentric-tube latent heat storage filled with cascaded PCMs. Obviously, this thermal performance of this unit better than single PCM storage tank. Zheng et al. [27] proposed an air-based 可以全面使用。例如,Sun 等人 [13] 开发了一种由五水硫代硫酸钠 (Na_(2)S_(2)O_(3)*5H_(2)O:}\left(\mathrm{Na}_{2} \mathrm{~S}_{2} \mathrm{O}_{3} \cdot 5 \mathrm{H}_{2} \mathrm{O}\right. 、三水乙酸钠 (CH_(3)COONa*3H_(2)O:}\left(\mathrm{CH}_{3} \mathrm{COONa} \cdot 3 \mathrm{H}_{2} \mathrm{O}\right. 和去离子水组成的共晶相变材料(PCMs)。复合相变材料提供了在寒冷环境中解决电池容量下降的替代方法。这项研究有利于高能效电池热管理系统,而不牺牲功率。Zhou 等人 [14] 旨在开发基于十二水合铝铵硫酸盐 (NH_(4)Al:}\left(\mathrm{NH}_{4} \mathrm{Al}\right.(SO_(4))_(2)*12H_(2)O\left(\mathrm{SO}_{4}\right)_{2} \cdot 12 \mathrm{H}_{2} \mathrm{O} (AASD)的新型复合相变材料,用于热能存储。建立了熔化/固化实验,以分析各种添加剂和热循环对基于 AASD 的复合相变材料的热存储/释放性能的影响。Fu 等人 [15] 使用由 NaAc*3H_(2)O\mathrm{NaAc} \cdot 3 \mathrm{H}_{2} \mathrm{O} 和作为相变材料以及膨胀石墨(EG)作为支撑材料组成的非共晶混合物,开发了一种用于地板辐射供暖热交换器的具有高热性能的新型复合相变材料。结果显示,含有 12%12 \% 谷氨酸的混合物较为有利,因为其合适的相变温度( 48.62^(@)C48.62{ }^{\circ} \mathrm{C} )和高相变焓(258.5 kJ*kg^(-1)\mathrm{kJ} \cdot \mathrm{kg}^{-1} )。Wang 等人 [16] 准备好的石墨粉/石蜡复合相变材料和石墨粉/石蜡/镍泡沫三元复合相变材料。这两种复合相变材料都能有效控制锂离子电池的表面温度上升,热效率也相似。但第二种复合相变材料有更好的温度均匀性。杨等 [17] 分析了铜肋上铜泡沫/石蜡复合相变材料的孔隙率、孔径和内部空洞对热导率的影响。结果显示,增加孔隙率会降低热导率,铜肋的内部空洞是影响热导率的重要因素。库斯科斯 [18] 研究了一个装有均匀大小球体的圆柱罐,石蜡作为相变材料。测试了工作流体的各种输入温度信号,结果用于多层配置并尽可能存储最大能量。肯萨里 [19] 回顾了在 120^(@)C120^{\circ} \mathrm{C} 至 1000^(@)C1000^{\circ} \mathrm{C} 温度范围内用于热能存储和太阳能的相变材料。 氟化物、氯化物和羟基盐以及硝酸盐、碳酸盐和金属合金的热物理性质被给出,一些材料的长期性质进行了分析。Dhaidan 等人[20]总结了 PCMs 在矩形腔、球形胶囊、管状或圆柱形腔以及环形腔中的熔化和对流热传递过程。讨论了容器的受限制熔化和不受限制熔化。不同容器的几何参数及其相应的影响因素也进行了分析。随后,他[21]进一步研究了不同容器结构中 PCM 的凝固/冻结过程。通过观察凝固/冻结过程,发现系统在凝固初期主要受对流热传递支配,逐渐转变为热传导。环形腔对排放的影响最小,而平面形状和垂直圆柱形腔对热释放时间和速率的影响最大。Muthya 等人 [22] 对复合相变材料(PCM)的形状稳定性理解并量化表示反对,这种材料将肉豆蔻醇与膨胀石墨以多种掺量混合。Cheng 等[23] 使用环氧树脂作为胶囊壳制备了微胶囊 PCM,微胶囊与不同类型的环氧树脂复合。结果表明,通过改变复合 PCM 中微胶囊 PCM 的比例,复合 PCM 的相变焓也会相应调整。Wang 等[24] 选择了硬脂酸作为 PCM,并使用 ZnO//\mathrm{ZnO} / 扩张石墨作为支撑材料。通过一系列测试分析,建议这种复合 PCM 具有优异的热稳定性和在热存储方面极好的潜力。Wei 等[25] 制备了具有可控熔点的 Al-Si//Al2O3\mathrm{Al}-\mathrm{Si} / \mathrm{Al} 2 \mathrm{O} 3 复合 PCM。这种复合 PCM 具有很好的重复使用性能和结构稳定性,适用于集中太阳能电站。Radouane 等[26] 模拟了包含级联 PCM 的三层同心管潜热存储单元的热性能。显然,这种单元的热性能优于单一 PCM 存储罐。Zheng 等[27] 提出了基于空气的
phase change cold storage unit with cascaded structure, one to five stages of PCMs were arranged in it and optimized based on exergy analysis. The results demonstrated that the average exergy efficiency has increased from single stage to five stages. Salilih et al. [28] investigated the transient thermal performance of a single u-tube vertical ground heat exchanger, n-octadecane PCM as a backfill grout material. Bianco et al. [29] based on experimental data by using a 2D axial-symmetric transient numerical model to investigate the performance. Under different geometrical features and chiller operating conditions. The results validated that PCM had better exploitation of the storage technology in cooling system. Rana et al. [30] researched the thermal performance of a heat exchanger filled with PCM. The exchanger having multiple elliptical tubes. Then they found that the elliptical tubes with fins would enhancement of heat transfer. The geometry of heat exchangers having elliptical tubes and circular tubes without fin, with two fins, and four fins also had been simulated. Abdulateef et al. [31] designed an energy storage system incorporated PCM, it was using a horizontal triplex tube heat exchanger with internal longitudinal fins. Longitudinal and triangular fins, were studied numerically. Lastly, the external triangular finned tube has been considered the most suitable. 相变冷存储单元具有级联结构,其中安排了一到五个阶段的相变材料(PCMs),并基于能量分析进行了优化。结果表明,从单阶段到五阶段,平均能量效率有所提高。Salilih 等人[28]研究了一根 U 形垂直地热交换器在不同瞬态热性能下的表现,使用十八烷作为填充材料。Bianco 等人[29]基于实验数据,通过使用二维轴对称瞬态数值模型来研究不同几何特征和制冷机运行条件下的性能。结果验证了相变材料在冷却系统中的存储技术利用效果更好。Rana 等人[30]研究了填充相变材料的热交换器的热性能,该热交换器具有多个椭圆形管。他们发现带有翅片的椭圆形管会增强热传递。还模拟了具有椭圆形管和无翅片的圆形管、两个翅片和四个翅片的热交换器的几何结构。Abdulateef 等人 [31] 设计了一个包含相变材料(PCM)的储能系统,使用了水平三管换热器且内部有纵向肋片。纵向肋片和三角形肋片进行了数值研究。最后,外部三角形肋片管被认为是最合适的。
This paper mainly introduces the research of PCHS enhancement technology. Firstly, the application and shortcomings of the technology are summarized. Then, combined with the strengthening methods, the performance of PCMs and optimization of the device are summarized, 这篇论文主要介绍了 PCHS 增强技术的研究。首先,总结了该技术的应用及其不足。然后,结合增强方法,总结了 PCMs 的性能和设备的优化。
the advantages and disadvantages are compared and analyzed. Lastly, suggestions and opinions are put forward by the author. 优缺点进行了比较和分析。最后,作者提出了建议和意见。
2. Application of phase change heat storage 2.相变热存储的应用
From what has been discussed above, phase change heat storage technology plays an important role in building energy conservation [32-34], automotive thermal management [35], thermal management of electronic equipment [36-38], solar energy system [39,40], energy storage [41,42] and other fields. This chapter will review its application (Fig. 1). 从上述讨论可知,相变热存储技术在建筑节能[32-34]、汽车热管理[35]、电子设备热管理[36-38]、太阳能系统[39,40]、储能[41,42]及其他领域中发挥着重要作用。本章将回顾其应用(图 1)。
As is known to all, the energy consumption of the construction industry is relatively large. Energy consumption can be reduced when the PCMs used into building materials [43]. The indoor temperature will be controlled, the residential comfort will be improved [44]. Qiao et al. [45] studied the solar heating wall (Fig. 2. (a)) filled with PCMs. Compare with the experimental room without PCMs heating wall, the heating wall with PCMs can save 1.93kW//h1.93 \mathrm{~kW} / \mathrm{h} of energy when the indoor temperature at 21.9^(@)C21.9^{\circ} \mathrm{C}. In addition, the application of PCMs in floor also can enhance the comfort of indoor living [46]. Zhou et al. [47] conducted an experimental to study the performance of low-temperature radiant floor heating system with different materials (sand and PCMs) (Fig. 2. (b)). The results showed, the heat release time of the PCMs floor heating system is about twice as long as that of the sand, and the heating 众所周知,建筑业的能源消耗相对较大。当将相变材料(PCMs)用于建筑材料时,可以减少能源消耗[43]。室内温度将得到控制,居住舒适度将得到提高[44]。乔等人[45]研究了填充有 PCMs 的太阳能加热墙(图 2. (a))。与没有 PCMs 加热墙的实验房间相比,当室内温度为 21.9^(@)C21.9^{\circ} \mathrm{C} 时,含有 PCMs 的加热墙可以节省 1.93kW//h1.93 \mathrm{~kW} / \mathrm{h} 的能源。此外,将 PCMs 应用于地板也可以提高室内居住的舒适度[46]。周等人[47]进行了一项实验,研究了不同材料(砂和 PCMs)的低温辐射地板供暖系统的性能(图 2. (b))。结果显示,PCMs 地板供暖系统的放热时间大约是砂的两倍,且加热