JOURNAL OF APPLIED POLYMER SCIENCE
·
2021
·Vol. 139
·期 1
·51422
·
IF 3.125
Fa Mao,Xuelai Zhang,Yongyichuan Zhang,Biao Liu,Lingyu Zheng
The main objective of this research is to characterize, via experimental analysis, the effects of thickeners on thermophysical properties of Alum (KAl[SO 4 ] 2 ·12H 2 O) as phase change material (PCM) for energy storage. Six thickeners, including sodium carboxymethyl cellulose (CMC-Na), sodium polyacrylate (PAAS), polyacrylamide (PAM), polyvinyl alcohol, xanthan gum (XG) and methylcellulose (MC), are added in Alum. Then the thermophysical properties and the cycle stability are tested and analyzed by step cooling experiment, differential scanning calorimeter, hot disk, scanning electron microscopy, high-low temperature alternating test chamber, X-ray diffraction (XRD), and Fourier transform infrared spectrometer (FT-IR). The results showed that the adding of 2 wt% CMC-Na, 1 wt% PAAS, 2 wt% PAM, 5 wt% XG, and 1 wt% MC to Alum can effectively reduce the subcooling of Alum while still maintaining the latent heat at a high level. After stability test with 60 melting-solidification cycles, the results indicate that Alum with 1 wt% MC has the best thermal cycle stability and has the highest latent heat (230 J/g). The latent heat is only 8.1% lower than that of pure Alum after 1 cycle, and 11.1% higher than that of pure Alum after 60 cycles. The XRD, FT-IR, and thermogravimetry results show that it has good chemical and thermal stability.
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 THERMOPHYSICS
·
2020
·Vol. 41
·期 5
·1-12
·
IF 0.794
Mo Songping,He Lijuan,Jia Lisi,Chen Ying,Cheng Zhengdong
Thermophysical properties are important parameters that influence the performance of phase change materials (PCMs) and heat transfer fluids. Micro/nanoencapsulation is an effective technique for preventing leakage and enhancing thermophysical properties of PCMs. In the present study, novel d -mannitol nanocapsules with inorganic shells were synthesized as a medium-temperature PCM. The nanocapsulation was confirmed by scanning electronic microscopy. The specific heat and thermal diffusivity of the nanocapsules and their suspension with heat transfer oil as base fluid were measured by a differential scanning calorimeter and light flash apparatus. The thermal conductivity of the nanocapsule suspension was measured using a hot-disk thermal constants analyzer. The viscosity of the nanocapsule suspension was measured by a rotational rheometer. The results show that the thermal conductivity and thermal diffusivity of the nanocapsules were enhanced compared to the bulk of the PCM due to the inorganic shell. The specific heat, thermal conductivity, and viscosity of the nanocapsule suspension were increased compared to the base fluid. The potential of the nanocapsule suspension as a heat storage and transfer fluid was evaluated.
研究领域:
材料科学
·
热力学
✓ 已验证
DOI
高影响因子
Journal of Energy Storage
·
2022
·
IF 8.907
Yang Tian,Xianglei Liu,Li Zhang,Qinyang Luo,Qiao Xu,Haichen Yao,Fengyi Yang,Jianguo Wang,Chunzhuo Dang,Yiming Xuan
The eutectic salt as latent heat storage (LHS) media has been widely employed in various fields, but its thermophysical properties are difficult to be predicted accurately. Here, a prediction model of thermophysical properties of eutectic salts based on the backpropagation (BP) artificial neural network method combined with bio-inspired algorithms (polar bear optimization (PBO) or genetic algorithm (GA)) is proposed. The average prediction error of melting temperature of 26 chlorine eutectic salts is the lowest by employing the BP-PBO algorithm, which is reduced by 42 % and 38 % compared to the BP algorithm and BP-GA, respectively. The advantage of BP-PBO is more obvious in predicting phase change enthalpy of chlorine eutectic salts, whose average error decreases by 71 % and 68 % compared with BP and BP-GA, respectively. For more intuitive comparisons, experiment measurements, BP-PBO, phase diagram , and molecular dynamics are used for characterizing thermophysical properties of fabricated KCl-LiCl eutectics. Again, BP-PBO demonstrates extremely accurate prediction performance and unique advantage of avoiding the difficulty of choosing appropriate phase equilibrium data or potential functions. The work provides accurate and fast prediction methods of thermophysical properties of chlorine eutectic salts and guides their designs for different applications.
研究领域:
材料科学
·
能源工程
✓ 已验证
DOI
高影响因子
SOLAR ENERGY MATERIALS AND SOLAR CELLS
·
2020
·
IF 6.984
Xuejiao Li,Na Li,Weihua Liu,Zhongfeng Tang,Jianqiang Wang
The first principle molecular dynamics (FPMD) simulations in combination with experimental measurements are applied to investigate the thermophysical properties and structural evolution of MgCl 2 –NaCl–KCl (MNK) eutectic . The densities, melting point, and enthalpy of fusion simulated by FPMD within NPT ensemble are consistent with experimental results. Besides, the thermal conductivity of molten MNK eutectic evaluated from FPMD simulations with NVT ensemble gives satisfactory result. Furthermore, the shear viscosities of MNK eutectic are deduced based on ion self-diffusion coefficients and solvodynamic radius, similar to the data estimated by additive contribution method. Eventually, the change rules of radial and angular distribution functions and structural factor of MNK eutectic during melting are revealed, and the melting mechanism is proposed from the evolution of polyhedral coordination structures. These results are heuristic in structure-activity relationship of MNK eutectic, which sheds insight for further development of efficient heat transfer and storage media through microstructure engineering.
研究领域:
材料科学
·
热物理
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2021
·
IF 6.165
Jing Fan,Liangliang Fan,Shuangshuo Liu,Fenhong Song
Globally, biofuel is considered as the largest renewable energy source to substitute the petrochemical fuel and it is thus received a great amount of attention from both developed countries and developing countries. Among all the biofuels, biodiesel is strongly recommended as a promising alternative fuel for traditional internal combustion engines. Thermal conductivity is an essential transport property of fuel, and is vital in the flow and heat transfer process. Therefore, it is necessary to conduct the research associated with fuel’s thermal conductivity . In this work, four binary fuel mixtures containing biodiesel components methyl caprate and ethyl caprate with n-undecane and n-tridecane were prepared respectively, and the liquid thermal conductivity of which were measured by the transient hot wire method system. The measurement was conducted at the temperature from 292 K to 362 K at atmospheric pressure. The experimental data reported here have an uncertainty of less than 2%. In addition, a correlation about the relationship between the liquid thermal conductivity with temperature and the esters’ concentration in different fuel blends has been correlated.
研究领域:
燃料化学
·
热物理性质
·
可再生能源
·
生物燃料
·
传热传质
✓ 已验证
DOI
高影响因子
SOLAR ENERGY MATERIALS AND SOLAR CELLS
·
2017
·
IF 4.784
Shaolei Xie,Jinhe Sun,Zhao Wang,Shang Liu,Lipeng Han,Guixiang Ma,Yan Jing,Yongzhong Jia
An oxalic acid dihydrate/boric acid (OCD-BA) binary eutectic mixtures containing 88 wt% OCD and 12 wt% BA was investigated as a novel phase change material (PCM) with high latent heat and thermal stability. The solid-liquid phase diagram of binary systems is established, and the phase change temperature of OCD-BA binary eutectic mixture is 87.3 °C and the latent heats of the melting and crystallization process are 344 J g −1 and 262 J g −1 , respectively. Its thermophysical properties and thermal stability were studied using differential scanning calorimetry (DSC), Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), and Scanning electron microscopy-Energy dispersive spectroscopy (SEM-EDS). Its thermal stability was investigated in situ through 100 cycles using DSC and 1000 thermal cycling tests using Refrigerated and heating circulators (RHC). The latent heat of melting still exceed 280 J g −1 after 1000 heating/cooling cycles. The heat release platform sustained 5 h at more than 70.0 °C, and the degree of supercooling was only 1.0 °C according to T-history method. These results indicate that the newly prepared OCD-BA binary eutectic mixture is a potential PCM for thermal storage tanks.
研究领域:
材料科学
·
热能存储
·
相变材料
·
热物性
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）