APPLIED ENERGY
·
2014
·
IF 5.261
Xing Li,Ying Chen,Zhengdong Cheng,Lisi Jia,Songping Mo,Zhuowei Liu
Graphene is widely utilized because of its exceptional properties, such as strong mechanical strength, low weight, nearly optical transparency, and excellent conductivity of heat and electricity. In this study, we used the ultrahigh specific surface area of graphene due to its inherently two-dimensional nature to reduce the subcooling of freezing of a phase change material. The results enable graphene’s application in energy storage using the latent heat of phase transition. The need for subcooling to freeze water was eliminated completely with the suspension of a very low mass fraction (0.020 ± 0.001 wt%) or surface area concentration (0.070 ± 0.003 m 2 /ml) of graphene. Compared to nanoparticles of SiO 2 and TiO 2 with the same mass fraction suspended in water, flakes of graphene led to freeze water at a much smaller subcooling degree, and shorter total freezing time. The addition of surfactants can improve suspension stability and further reduce the degree of subcooling, but it also slightly increases the total freezing time. Graphene flakes are more suitable than spherical oxide nanoparticles for use as nucleating additives in water.
研究领域:
材料科学
·
能源存储
✓ 已验证
DOI
高影响因子
Journal of Energy Storage
·
2023
·
IF 9.4
Xue-Feng Shao,Sheng Yang,Hong-Yi Shi,Li-Wu Fan,Yan-Ping Yuan
Sugar alcohols have been proposed as a class of potential phase change materials (PCMs) for medium-temperature latent heat storage . The present work investigated the cycling stability of four pure and three mixture sugar alcohols by a specially-designed test setup, followed by a comprehensive evaluation based on their phase change behaviors (reported in our previous publication) and stability. It was found that the latent heats of fusion/crystallization degrade upon consecutive melting-crystallization cycles, and a higher degree of superheat Δ T sh leads to a faster degradation. An extremely low level of only 10.5 % degradation was obtained for erythritol after 200 cycles at a relatively low Δ T sh of 20 °C. The corresponding degrees of supercooling Δ T sc become higher due to the remarkable reduction of crystallization temperatures . It was shown that introducing protective nitrogen gas could suppress oxidation and improve cycling stability. The cycles of half degradation on latent heat of fusion was ~3.6 times with nitrogen protection. A comprehensive evaluation identified that the crystallization-related issues and poor stability are the primary challenges for sugar alcohols. Nevertheless, other than common PCMs, some particular application scenarios like controllable latent heat retrieval and seasonal heat storage can be hopefully developed by virtue of the deep supercooling nature of sugar alcohols.
研究领域:
材料科学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
Nanoscale Research Letters
·
2018
·Vol. 13
·期 1
·1-10
·
IF 3.125
Cui Wei,Jia Lisi,Chen Ying,Li Yi’ang,Li Jun,Mo Songping
Nanoparticles, including Al 2 O 3 and SiO 2 , and ultrasound were adopted to improve the solidification properties of water. The effects of nanoparticle concentration, contact angle, and ultrasonic intensity on the supercooling degree of water were investigated, as well as the dispersion stability of nanoparticles in water during solidification. Experimental results show that the supercooling degree of water is reduced under the combined effect of ultrasound and nanoparticles. Consequently, the reduction of supercooling degree increases with the increase of ultrasonic intensity and nanoparticle concentration and decrease of contact angle of nanoparticles. Moreover, the reduction of supercooling degree caused by ultrasound and nanoparticles together do not exceed the sum of the supercooling degree reductions caused by ultrasound and nanoparticles separately; the reduction is even smaller than that caused by ultrasound individually under certain conditions of controlled nanoparticle concentration and contact angle and ultrasonic intensity. The dispersion stability of nanoparticles during solidification can be maintained only when the nanoparticles and ultrasound together show a superior effect on reducing the supercooling degree of water to the single operation of ultrasound. Otherwise, the aggregation of nanoparticles appears in water solidification, which results in failure. The relationships among the meaningful nanoparticle concentration, contact angle, and ultrasonic intensity, at which the requirements of low supercooling and high stability could be satisfied, were obtained. The control mechanisms for these phenomena were analyzed.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
HEAT AND MASS TRANSFER
·
2022
·Vol. 59
·期 5
·851-857
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IF 2.325
Zhang Qian,Ma Fukun,Tan Wenjie,Liu Liqiang,Jing Min,Sun Tao
Inorganic hydrated salt calcium chloride hexahydrate (CaCl 2 ·6H 2 O) has a broad application prospect in the field of phase change energy storage due to its own characteristics. However, it has some problems such as large supercooling and serious phase separation, which limit its practical application. In this paper, boron nitride nanosheets (BNNSs) were applied in the CaCl 2 ·6H 2 O system. It was found that the heterogeneous nucleation of CaCl 2 ·6H 2 O can take place on the surface of BNNS. BNNS can solve the supercooling and heat transfer problems of CaCl 2 ·6H 2 O effectively. At the same time, the addition of an appropriate amount of BNNSs can improve the stability of phase change composites. Compared with pure CaCl 2 ·6H 2 O (supercooling was 22.06 °C and thermal conductivity was 0.382 W·m −1 ·K −1 ), the supercooling of CaCl 2 ·6H 2 O/1 wt% BNNS composite was only 3.89 °C and the thermal conductivity was 3.918 W·m −1 ·K −1 . CaCl 2 ·6H 2 O/0.5 wt% BNNS composite has good cycling stability. This study has scientific significance for the development and application of BNNSs in the field of phase change energy storage.
研究领域:
材料科学
·
能源存储
✓ 已验证
DOI
高影响因子
CRYSTAL GROWTH & DESIGN
·
2018
·
IF 3.972
Shijie Xu,Yifu Chen,Junbo Gong,Jingkang Wang
In this contribution, by employing the Poisson distribution combined with the regular solution theory in the classical nucleation theory (CNT) framework, we construct a new model to uncover the relationship between induction time (tind) and supercooling (ΔT) and saturation temperature (T0) at different specific probabilities. By choosing the urea aqueous solution as a benchmark system, we show that the value of ln(1/tind) follows a reasonable linear relationship with (T0/ΔT)2/(T0 – ΔT), except the probability value tends to be 0 or 1. Furthermore, we also shed new light on the role of chemical potential difference and nucleation temperature in determining the nucleation rate; namely, although the chemical potential difference is the driving force for the crystallization process, it does not always favor the nucleation process. We demonstrated that when the chemical potential difference increases as the nucleation temperature decreases (ΔT gradually increases), in this case, the kinetic factor overwhelms the thermodynamic factor thus leading to a faster nucleation rate by employing the CNT theory. However, when the chemical potential difference decreases as the nucleation temperature increases, we found that increasing the nucleation temperature favors the nucleation process both in kinetic and thermodynamic aspects.
研究领域:
物理化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
RENEWABLE ENERGY
·
2016
·
IF 3.404
Wenlong Cui,Yanping Yuan,Liangliang Sun,Xiaoling Cao,Xiaojiao Yang
This paper reports that Nano-copper (Nano-Cu), which possesses high thermal and electrical conductivity, as an additive, can improve the supercooling properties of sodium acetate trihydrate (CH 3 COONa·3H 2 O, SAT) and enhance its thermal conductivity . To investigate the effect of Nano-Cu content on the degree of supercooling of SAT, composite phase change materials containing SAT, Nano-Cu (0.4%, 0.5%, 0.6%, 0.7% and 0.8%), CMC (thickening agent) and sodium dodecyl sulfonate (C 12 H 25 NaO 3 S, dispersant) were prepared. Melting-freezing experiments involving the composite materials indicated that the rate of heat transfer increased by nearly 20%. When an optimal amount of Nano-Cu (i.e., 0.5%) was added to SAT, the degree of supercooling was reduced to approximately 0.5 °C. Compared to the use of inorganic salt hydrates as nucleating agents , Nano-Cu is significantly advantageous in reducing the degree of supercooling of SAT. The maximum improvement in supercooling was observed when the melting-freezing experiment was conducted at an initial temperature of 70 °C. The thermal conductivity of the reported composite phasechange materialsis approximately 20% higher than that of pure SAT.
研究领域:
材料科学
·
热能工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Energy Storage
·
2025
·
IF 9.8
Chenzhen Liu,Baohuan Li,Siwen Wang,Peng Yang,Kai Qi,Guangtong Zhang,Zhonghao Rao
Sugar alcohol phase change materials (PCMs) have garnered extensive attention in the field of medium to low-temperature thermal energy storage due to their high latent heat. However, their application is limited by supercooling and low thermal conductivity. In this paper, a series of porous alumina ceramics with varying porosities (62 % to 83 %) were fabricated using a freeze-casting method as supporting frameworks for loading sugar alcohol phase change materials, resulting in high-performance, leakage-proof, and shape-stabilized sugar alcohol composite phase change materials. The effects of various additives and alumina content on the porosity of the porous ceramics were investigated. The thermal conductivity, phase change property, and supercooling of sugar alcohol composite phase change materials were measured. The thermal conductivity of ET-APC-56 was 4.82 W/(m·K), which was an increase of 690 % compared to erythritol (ET). The phase change enthalpy of ET-APC-28 was 225 J/g, and it still retained 202.8 J/g after 500 thermal cycles. The supercooling of ET-APC-28 was reduced from 59.1 °C to 8.9 °C. Additionally, leakage tests showed no significant leakage in any of the samples. The prepared sugar alcohol composite phase change materials demonstrated excellent thermal performance, indicating broad application prospects in the field of medium to low-temperature phase change thermal energy storage.
研究领域:
材料科学
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能源工程
✓ 已验证
产品关联
DOI
高影响因子
Processes
·
2023
·Vol. 11
·期 9
·2720
·
IF 3.5
Zhen Xu,Lei Zheng,Zhen Dong,Aixian Liu,Yiwei Wang,Qiang Sun,Jianyi Chen,Xuqiang Guo
The adhesion between a hydrate and a pipe wall is the main cause of hydrate deposition and blockage. In this study, the adhesion strength of semi-clathrate hydrate (tetrabutylammonium bromide hydrate) to four kinds of solid surfaces (E235B carbon steel, E355CC low alloy steel, SUS304 stainless steel, and polytetrafluoroethylene) was measured. This investigation reveals that the adhesion strength of the hydrate to a solid surface is negatively correlated with the wettability of the solid surface, which suggests that hydrophobic materials effectively reduced the hydrate adhesion to the pipe wall. The surface roughness showed different effects on the adhesion of the hydrate to hydrophilic or hydrophobic surfaces. To be specific, when the surface roughness increased from 3.2 µm to 12.5 µm, the hydrate adhesion strength to the hydrophilic surface of SUS304 increased by 123.6%, whereas the hydrate adhesion strength to the hydrophobic surface of polytetrafluoroethylene only increased by 21.5%. This study shows that low wettability and low surface roughness effectively reduce the critical rate required to remove hydrate deposition, which achieves the self-removal of hydrates. At the same time, it was found that the adhesion strength of the hydrate to surfaces increases with increasing subcooling. This investigation holds significant theoretical implications for designing self-cleaning surfaces for oil and gas pipes.Keywords:hydrate;adhesion strength;surface wettability;surface roughness;subcooling
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
·
2019
·Vol. 43
·期 13
·7058-7074
·
IF 3.343
Zhiwei Yang,Zijuan Yang,Jinhong Li,Yong Deng,Lijie Liu,Xuezhu Luan,Kaiyue Huang
Summary In this work, diatomite (DM) was calcined at 400°C to obtain the pure surface and pores (DM-1); then, the three kinds of shape-stable composite phase change materials (ss-CPCMs) of CaCl 2 ·6H 2 O (CCH)/DM-1, CH 3 COONa·3H 2 O (SAT)/DM-1, and Na 2 SO 4 ·10H 2 O (SSD)/DM-1 were prepared by impregnation method. The hydrated salts were uniformly adsorbed on the surfaces and into the pores of DM-1 by capillary action and surface tension. The addition of nucleating agent effectively reduced the supercooling degrees of hydrated salts, and the heterogeneous nucleation mechanism was employed to explain the supercooling suppression. The results showed that the supercooling degrees of the three hydrated salt ss-CPCMs with optimal nucleating agent were less than or equal to 0.6°C. Moreover, the thermal conductivities of ss-CPCMs were significantly improved by adding graphite, and the addition of 10 wt% graphite could increase the thermal conductivity of hydrated salt ss-CPCMs by at least 70%. The package capacity of CCH, SAT, and SSD in three ss-CPCMs with appropriate contents of nucleating agent and graphite was 58.1, 56.1, and 56.3 wt%, respectively. The DSC results showed that the phase change temperatures of the three ss-CPCMs were approximately 28.8 to 57.8°C, and the latent heat was approximately 108.7 to 149.4 J/g. The XRD and FT-IR results exhibited that the three ss-CPCMs indicated understanding chemical compatibility. In addition, the results of 200 melt-solidification cycles demonstrated that the ss-CPCMs had excellent thermal cycle reliability. Thus, the hydrated salt/DM-1 ss-CPCMs showed great potential as heat storage materials for various heat storage applications.
研究领域:
材料科学
·
能源工程
✓ 已验证
DOI
高影响因子
Catalysts
·
2022
·Vol. 12
·期 2
·205
·
IF 4.501
Haodong Tang,Xiali Zheng,Yun Yu,Jinxin Liang,Yifan Zheng,Zongjian Liu
SiO2encapsulated SnZnCu microspheres (several micrometers to about 30 μm in diameter) with very low undercooling, narrow freezing/melting range, and high thermal cycling stability have been produced and used as the temperature stabilizer of the packed bed in highly exothermic Fischer–Tropsch reaction. The core–shell structured SnZnCu@SiO2microspheres are prepared in a two-step way, namely SnZnCu microspheres are firstly produced via a molten LiCl–KCl–CsCl eutectic-based metal emulsion method, and then a sol–gel approach is employed to coat them with a uniform, anti-leakage SiO2layer. It is found that raising the amount of Zn to 4.0 at.% is critical for achieving a very low undercooling (<5 °C for SnZn0.04Cux@SiO2vs. about 84 °C for Sn@SiO2) and a narrow freezing/melting peak width, and both undercooling and peak width are almost unchanged as the Cu content (x) increases from 1.5 to 3.0 at.%. However, their thermal cycling stability depends positively on the amount of Cu and can be remarkably improved when 3.0 at.% Cu is added. The results also show that low undercooling and narrow freezing/melting peak width are associated with the formation of Sn–Zn–Cu ternary eutectic and metastable phase Cu5Zn8, and poor thermal cycling stability of SnZn0.04Cux@SiO2microspheres with low Cu content is related to the decomposition of Cu5Zn8during thermal cycling. By embedding thermally stable SnZn0.04Cu0.03@SiO2microspheres into the Co/SiO2catalyst for Fischer–Tropsch synthesis, the temperature gradient in the catalyst bed can be significantly reduced by suppressing the formation of hot spots or thermal runaway and thus rapid deactivation of Co catalyst that occurs in the SnZn0.04Cux@SiO2-absent Co/SiO2catalyst can be avoided.Keywords:exothermic reaction;microcapsules;phase change materials;SiO2;Sn–Zn–Cu
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
SOLAR ENERGY MATERIALS AND SOLAR CELLS
·
2020
·
IF 6.984
Ni Tan,Ting Xie,Yang Feng,Ping Hu,Qi Li,Liu-Mo Jiang,Wen-Bo Zeng,Ju-Lan Zeng
Sepiolite (Sep) and exfoliated graphite nanoplatelets (xGnP) were applied as supporting material and thermal conductive fillers to solve the problems of possible leakage, low thermal conductivity and high supercooling of m -erythritol (ME) as a phase change material (PCM). The loading of ME in the ME/Sep form-stable PCMs could attain 56 wt% when the Sep was treated by 2.5 M HCl and heated at 800 °C for 1 h. The form-stable PCMs were basically physical mixtures though there were some interactions occurred between the hydroxyl groups of ME and Sep. The thermal stability of ME was improved after it was confined in the supporting materials. In addition, the thermal conductivity of the ME/Sep/xGnP form-stable PCM containing 56% ME and 8.0 wt% xGnP could be enhanced to 0.756 W/mK, which was 103% higher than the corresponding ME/Sep form-stable PCM. Moreover, the transient temperature response of the form-stable PCMs was greatly improved by Sep and xGnP. Furthermore, the supercooling of ME could be decreased from 80 °C for pure ME to about 30 °C in the ME/Sep/xGnP form-stable PCM containing 56% ME and 8.0 wt% xGnP. Besides, the latent heat recovery ratio of the ME/Sep/xGnP form-stable PCMs were also greatly improved.
研究领域:
材料科学
·
热能工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Energy Storage
·
2022
·
IF 8.907
Qingjiang Cheng,Xiuli Cheng,Xue Wang,Peixing Du,Chenzhen Liu,Zhonghao Rao
Erythritol has many advantages such as high latent heat, good stability, non-toxicity and abundance, which are extremely potential in the field of medium-temperature thermal energy storage . However, the application of erythritol in thermal energy storage is greatly restricts by high supercooling. Herein, sodium carboxymethyl cellulose (CMC Na) and hexagonal boron nitride (h-BN) are introduced to regulate the supercooling and thermal properties of erythritol. The crystal growth and nucleation process of erythritol is promoted effectively by CMC-Na and h-BN, as a result, the supercooling degree and solidification stability degree of erythritol is suppressed observably. According the results, while retaining the high latent heat of erythritol, the defect of supercooling of erythritol is effectively improved. The supercooling degree and solidification stability degree of erythritol are suppressed by 93% and 84%, respectively. Furthermore, the high latent heat, good thermal conductivity and excellent cycling thermal stability of erythritol composite phase change materials (ECPCM) are also available. This conclusion is important for supercooling regulation and thermal property optimization of erythritol, and indeed, can promote the utilization of erythritol in medium-temperature thermal energy storage.
研究领域:
材料科学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）