SOLAR ENERGY
·
2018
·
IF 4.374
Xiuli Wang,Xiaomin Cheng,Yuanyuan Li,Ge Li,Jun Xu
A self-assembly method is introduced to prepare composite phase change materials (PCMs) consisting of 1-octadecanol (OD) and graphene. The shape stability and thermal properties of 1-octadecanol/graphene composite PCMs with three-dimensional network structure are investigated. Graphene is dispersed evenly in OD matrix and the three-dimensional network structure is getting tighter with increasing ratio of graphene. OD is completely encapsulated at relatively low amount of graphene about 1.5 wt%. XRD and Raman results show that the combination between OD and graphene is physical adsorption. The 1-octadecanol/graphene (OG) composite phase change materials possess excellent shape stability, which can prevent the leakage of molten OD during phase transition. In addition, around 99.3% phase change enthalpy of pure OD is maintained by connected network structure of graphene while the melting and solidifying temperature merely have small fluctuations. The thermal conductivity of composite phase change material with 1.5 wt% graphene increases to 0.358 W/(m K), which is 1.5 times higher than that of pure OD. Furthermore, the porous network of graphene can delay the evaporation and thermal decomposition point of the composite phase change materials, thus extending the operating temperature of OD efficiently. This work provides a promising way to encapsulate low-temperature organic phase change materials with little carbon additives, and enhance the thermophysical properties of base materials simultaneously.
研究领域:
材料科学
·
能源工程
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
·
2020
·Vol. 44
·期 11
·8555-8566
·
IF 3.741
Li Yang,Yanping Yuan,Nan Zhang,Yanfang Dong,Yafen Sun,Wenhui Ji
Summary To make better use of solar energy, lauric acid/expanded graphite (LA/EG) composite phase change materials (PCMs) were synthesized to collect and store solar energy as latent heat thermal energy. The results of thermal characteristics show that when the mass fraction of EG is 5%, 10%, and 15%, the latent heat of LA/EG is 164.5, 156.9, and 148.0 J/g, and the thermal conductivity is 2.73, 7.98, and 10.54 W/(m·K). Leakage test shows that LA/EG PCMs with EG mass fraction of 10% and 15% are form stable after phase change. One thousand thermal cycles prove good thermal reliability of LA/EG. TG analysis indicates LA/EG PCMs have good thermal stability within operating temperature range. The Ultraviolet-visible spectra reveal that the absorbance of LA/EG composite PCMs would increase as the mass fraction of EG increases. Photothermal conversion experiment results indicate that the photothermal conversion efficiency of LA/EG composite PCMs increases as the mass fraction of EG increases, and the efficiency can reach 95% when the mass fraction of EG is 15%. Moreover, it was also found that the process of photothermal conversion can be accelerated with stronger illumination intensity or smaller heat transfer size. All the results show that the prepared LA/EG PCMs can convert solar energy into thermal energy and store it in the form of latent heat at the same time, which indicates it has promising prospect in the application of solar energy conversion and storage.
研究领域:
材料科学
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能源化学
·
热能工程
·
功能材料
·
可再生能源
✓ 已验证
DOI
高影响因子
Journal of Energy Storage
·
2021
·
IF 6.583
Tiantian Zhang,Shi Juan,Wang Yi,Zhenqian Chen
Halloysite nanotube (HNT), a natural and environmentally friendly low-cost material with significant reserves, has become one of promising candidates for preparation of form-stable composite PCM with satisfactory thermal properties owing to their hollow tubule structure and high surface area. The present work prepared the form-stable composite with HNTs and acid etching HNTs (A-HNTs) and compares the properties closely related to thermal energy storage application. Specifically, the micromorphology, thermal properties, shape-stabilized properties, as well as thermal conductivities of the composite materials were characterized by utilizing SEM, TEM, FTIR, DSC, BET, and Hot-disk wire methods, respectively. The results showed that the n-octadecane can both adhere on the inner lumen and the outer wall of HNTs and A-HNTs, while the A-HNTs possess significantly improved absorption thanks to the fact that the pore volume of A-HNTs was enlarged by 19.2% in comparison with HNT, which empowers the extra 5.8% phase transition enthalpy of n-octadecane@A-HNT. In addition, the composite PCMs have a good long-term thermal stability based on multi-cycle heat absorption and release further highlights the potentials in thermal storage application.
研究领域:
材料科学
·
纳米科技
·
能源材料
·
热力学
·
环境友好材料
✓ 已验证
DOI
高影响因子
Energy Technology
·
2017
·Vol. 5
·期 8
·1322-1327
·
IF 2.789
Shaolei Xie,Jinhe Sun,Shang Liu,Lipeng Han,Guixiang Ma,Yan Jing,Yongzhong Jia
An adipic acid/boric acid (AA–BA) binary eutectic mixture containing 80 wt % adipic acid and 20 wt % boric acid was investigated as a new phase change material (PCM) with high latent heat, high thermal stability, and low cost. The material′s thermophysical properties and thermal stability were studied using differential scanning calorimetry (DSC), X-Ray Diffraction (XRD), and thermogravimetric analysis (TGA). The thermal stability was investigated in situ over 100 cycles using DSC. The phase change temperature of the AA–BA binary eutectic mixture was 135.04 °C and the latent heats of the melting and crystallization process were 283.42 and 272.16 J g −1 , respectively. The latent heat of melting only dropped 4.94 % after in situ 100 cycles using DSC. Following comparison of thermal properties and price of the AA–BA eutectic mixture PCM with those of some composite PCMs, the results indicate that the newly prepared AA–BA eutectic mixture is a potential phase change material for thermal storage tanks.
研究领域:
材料科学
·
热力学
·
能源存储
·
化学工程
·
功能材料
✓ 已验证
DOI
高影响因子
SOLAR ENERGY MATERIALS AND SOLAR CELLS
·
2023
·
IF 6.9
Xuefeng Shao,Yeke Chenxu,Binrui Wang,Nan Zhang,Yanping Yuan
Towards latent heat storage for days, or even extending to months in the context of solar energy utilization, the exploration of phase change materials (PCMs) with stable supercooling and the following crystallization triggering are carried out. The present work confirmed the persistent supercooling property of the xylitol/erythritol eutectic mixture. The coupled technique combining mechanical agitation with seeding was proposed to trigger crystallization, so as to facilitate the heat retrieval whenever heat is in demand. The xylitol/erythritol eutectic keeps supercooling state without crystallization at ambient temperature for at least 10 days, thus it can serve as applicable PCM for controllable heat retrieval. Such severe supercooling is mainly attributed to the particular molecular structure of polyalcohols and dramatic increase of dynamic viscosity . In particular, on the basis of secondary nucleation principle, the coupled technique combining mechanical agitation and seeding can be a preferable technique to efficiently trigger crystallization of the present eutectic PCM , so as to realize controllable heat retrieval. Such combined technique has main advantages of high efficiency and reproducible crystallization process . The agitation duration is shortened to 1.8 min with seeding, in comparison to a longer value of 43.3 min without seeding. Although the single technique of mechanical agitation can also trigger the crystallization, the agitation is found to be time-consuming and the triggered crystallization process is in poor consistency among parallel specimens. Furthermore, the crystallization initiating is greatly advanced with high agitation rate (300 r/min), and the agitation duration to sufficiently activate crystallization can be significantly shortened. The results suggest that appropriately high agitation rate favors the efficient heat retrieval. The obtained results are helpful to gain a better understanding on the supercooled PCMs based controllable heat retrieval.
研究领域:
材料科学
·
热能存储
·
物理化学
·
能源材料
·
传热学
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Qijing Guo,Hao Yi,Feifei Jia,Shaoxian Song
Phase change materials (PCMs) offer significant advantages in energy conversion and storage by facilitating the storage and release of thermal energy during phase transition processes. However, challenges such as leakage during PCM phase transitions and poor light absorption properties have constrained their application in the field of photothermal energy storage. In this study, Montmorillonite (Mt) and molybdenum disulfide (MoS 2 ) has been used to design and synthesize hybrid aerogels (MoS 2 /Mt) boasting high mechanical strength and excellent photothermal conversion performance. These aerogels are then used to encapsulate polyethylene glycol (PEG) to prepare composite PCMs with outstanding solar-thermal conversion and storage performances. The results show that the synthesized MoS 2 /Mt-PEG composite PCMs exhibit high enthalpies of melting and solidification of 169.16 J/g and 170.78 J/g, respectively, while the aerogel supporting material has a high compressive modulus of 1.96 MPa. Moreover, the composite material displayed excellent thermal stability and leakage resistance after undergoing 30 melting-cooling cycles. Furthermore, the incorporation of MoS 2 imparted outstanding light absorption properties to the MoS 2 /Mt-PEG composite, resulting in a high light absorption and photothermal conversion-storage efficiency of 93.4 % and 96.47 %, respectively. Synthesized composite PCMs also demonstrate outstanding performance in solar-thermal-electricity conversion, achieving a voltage output of 458 mV under illumination conditions and maintaining a sustainable voltage output even after removing the light source. Thus, the composite PCMs prepared in this work can meet the requirements of high enthalpy, effective leakage prevention, efficient solar-thermal conversion and solar-thermal-electricity conversion performance, thereby presenting potential applications in practical solar energy collection, conversion, and storage.
研究领域:
材料科学
·
能源化学
·
纳米复合材料
·
热能存储
·
光热转换
✓ 已验证
DOI
高影响因子
Case Studies in Construction Materials
·
2024
·
IF 6.5
Ya Yin,Lan Qiao,Qingwen Li,Lu Chen,Miao Miao,Jinshui Dong,Linbo Song,An Luo,Haiqi Zheng
The functional backfilling in mining achieves synergistic co-mining of deep-earth deposits-geothermal, and the development of functional filling materials with suitable phase change parameters and excellent physicochemical properties is imminent. This study aims to investigate the optimal composition of phase change energy storage backfill material based on MicroPCM. To address the issues of reduced compressive strength and specific heat capacity of MicroPCM-backfill, silicon carbide (SiC) is introduced to prepare MPSC-backfill. Box-Behnken Design (BBD) is proposed to design and analyze according to four factors (ash-sand ratio, slurry concentration, MicroPCM, SiC), three levels (compressive strength, thermal conductivity, specific heat capacity) and three center points. Based on the Response Surface Methodology, the multivariate quadratic polynomial model was used to perform multiple linear regression and binomial fitting analysis to explore the optimal ratio. Combined with SEM-EDS (Scanning Electron Microscope with Energy-Dispersive X-ray Spectroscopy) analysis, the following conclusions were drawn. SiC exhibits an overall enhancement of the compressive strength of the backfill, and the thermal conductivity tends to increase almost linearly. The specific heat capacity grows in a small amount of silicon carbide doping, but excessive amounts lead to a decrease, with an overall limited impact. The addition of SiC does not affect the phase change ability of MicroPCM. And within a certain range of added quantities, it optimizes specific heat capacity, thermal conductivity, and compressive strength. Experimental validation based on the obtained optimal composition shows errors within a 5% margin, indicating the response model's good accuracy and predictability. High and low-temperature cyclic tests confirm the long-term thermal energy storage stability of MPSC-backfill during phase change cycles.
研究领域:
材料科学
·
矿业工程
·
热能存储
·
功能材料
·
物理化学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Mengdi Yuan,Chao Xu,Tieying Wang,Tianying Zhang,Xinyu Pan,Feng Ye
The serious supercooling of erythritol (ET) limits its application in the field of mid-temperature thermal energy storage (TES), especially in the recently developed form-stable phase change materials (PCMs). The primary purpose of this paper is to find out the factors to mitigate the supercooling of ET/expanded graphite (EG) form-stable composite PCM and obtain the correlation among the morphology, kinetic parameters, and a supercooling degree in the non-isothermal crystallization process. Firstly, five types of supercooling relaxation agents (nano-Al 2 O 3 , nano-SiO 2 , CMC, urea, and citric acid) were added to prepare the ET/EG form-stable CPCMs. Among them, the ET/EG/nano-Al 2 O 3 exhibited excellent form-stable ability, a high heat release ratio of 78.9%, and the lowest supercooling degree (Δ T ) of 45.7 °C. Based on the chosen ET/EG/nano-Al 2 O 3 CPCM, the tablet pressures from 1 to 13 MPa were applied, obtaining lowest Δ T decreased by 59.0% in 1 MPa. Moreover, the non-isothermal crystallization processes were discussed on the ET/EG/nano-Al 2 O 3 with the Avrami equation modified by Jeziorny. ET tended to grow spherulites under the high cooling rate of 18 °C/min with triggering as the Johnson-Mehl-Avrami exponent n increased to 4.22. Meanwhile, the supercooling degree increased from 48.8 to 56 °C with the cooling rate growing from 2 to 18 °C/min. And the activity energy Δ E of the ET/EG/nano-Al 2 O 3 CPCM (7092.35 kJ/mol) was smaller than that of the ET/EG CPCM (8211.19 kJ/mol) because of the interaction between the heterogeneous nucleation effect and blocker effect of nano-Al 2 O 3 .
研究领域:
材料科学
·
热能存储
·
物理化学
·
复合材料
·
能源材料
✓ 已验证
DOI
高影响因子
APPLIED THERMAL ENGINEERING
·
2016
·
IF 3.043
Min-Jie Liu,Li-Wu Fan,Zi-Qin Zhu,Biao Feng,Han-Cong Zhang,Yi Zeng
In order to study quantitatively the inward solidification heat transfer of a phase change material (PCM) enclosed in spherical capsules, an experimental method was proposed in this Technical Note, which is based upon measurement on the instantaneous volume shrinkage of the PCM during solidification. The shrunk volume was compensated continuously by an extra amount of liquid PCM preserved in a tube, and the descending height in the tube was recorded to calculate the volume shrinkage. Other quantities of interest, solidification fraction and surface-averaged heat flux for example, were readily reduced as single-valued functions of the volume shrinkage. Using 1-tetradecanol as the PCM, the proposed method was realized in laboratory with a stainless steel spherical capsule having an inner diameter of approximately 60 mm. Parallel tests were carried out for a set of three boundary cooling temperatures. It was shown that the measured descending heights are reproducible and are in agreement with the theoretical maximum values approaching the end of solidification. The experimental results were then discussed with an emphasis on the transient variations of solidification and heat transfer. Correlations were obtained for both solidification fraction and surface-averaged Nusselt number with respect to the product of Fourier and Stefan numbers.
研究领域:
热科学与工程
·
储能技术
·
传热传质学
·
材料科学
·
能源工程
✓ 已验证
DOI
高影响因子
CHINESE CHEMICAL LETTERS
·
2016
·Vol. 28
·期 1
·49-54
·
IF 1.947
Qi-Feng Li,Chao Wang,Xiao-Zheng Lan
Latent heat storage performance of a layered perovskite-type compound, 1-C 14 H 29 NH 3 ) 2 ZnCl 4 (C 14 Zn), embedded in a series of silica gel (SG) with pore sizes of d = 15–200 nm is investigated using differential scanning calorimetry (DSC), and powder X-ray diffractions (XRD). C 14 Zn in the nanopores of silica gel shows size-dependent phase transition temperature, enthalpy change and supercooling. They have a stable transition temperature and heat capacity at each size in a short-term thermal cycling. Similar X-ray diffraction patterns are observed for the nano-sized and the bulk C 14 Zn. The encapsulation of a phase change material in nanopores is a new way of tuning its thermal energy storage properties for a wider range of temperature regulation.
研究领域:
材料科学
·
热力学
·
纳米科技
·
能源存储
·
功能材料
✓ 已验证
DOI
高影响因子
MATERIALS LETTERS
·
2014
·
IF 2.269
Yaguang Yuan,Yanping Yuan,Nan Zhang,Yanxia Du,Xiaoling Cao
Capric–myristic–palmitic acid ternary eutectic mixture (CA–MA–PA) was prepared as phase change material (PCM). A novel composite PCM of CA–MA–PA/expanded graphite (EG) with an optimum mass ratio (CA–MA–PA:EG=13:1) was prepared by uniformly absorbing CA–MA–PA into the porous network structure of the EG. The melting and freezing temperatures of CA–MA–PA/EG composite PCM were measured by differential scanning calorimeter as 18.61 °C and 16.58 °C, respectively, while the melting and freezing latent heats were 128.2 J/g and 124.5 J/g, respectively. The thermal conductivity of the CA–MA–PA/EG composite PCM was measured as 3.67 W/m K and thus the thermal storage and release rates were significantly increased. The thermal cycling test results showed that CA–MA–PA/EG composite PCM has a good thermal reliability. All the above results show that the CA–MA–PA/EG composite PCM is a potential solution for latent heat storage system.
研究领域:
材料科学
·
能源化学
·
热物理
·
功能材料
·
储能技术
✓ 已验证
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2019
·
IF 3.375
Tongtong Shen,Hao Peng,Xiang Ling
In this study, the phase diagrams for the binary systems of n-C11H24–n-C14H30, n-C12H26–n-C13H28, n-C12H26–n-C14H30, and n-C13H28–n-C15H32 were experimentally investigated to employ potential phase change materials (PCMs) for cryogenic applications. Besides, the phase diagrams were theoretically obtained on the basis of the ideal solubility and UNIFAC models, and the UNIQUAC, Wilson, and NRTL models were applied to build correlations between experimental and predicting values. The results show that the compositions of the eutectic points appear at 10 wt % C14 for the C11–C14 system, 17.8 wt % C13 for the C12–C13 system, 18 wt % C14 for the C12–C14 system, and 10 wt % C15 for the C13–C15 system with eutectic temperatures of 246.85, 257.75, 260.45, and 265.55 K, respectively. Moreover, the melting temperatures calculated using the theoretical models are in good agreement with the experimental results. The average relative deviations for the C11–C14 system and C13–C15 systems are merely 0.3814% and 0.3220%, respectively, by using the NRTL model. Simultaneously, the minimum relative deviations for the C12–C13 and C12–C14 binary systems are 0.3649% for the ideal solubility model and 0.4856% for the UNIFAC model. Finally, upon comparing the predicted results of the studied binary systems using the results of the five models, we find that the UNIFAC model provides the most accurate results for the melting temperatures.
研究领域:
热力学
·
储能技术
·
化学工程
·
相变材料
·
低温工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）