Materials
·
2024
·Vol. 17
·期 18
·4611
·
IF 3.1
Chuang Zhu,Minhao Xu,Baiyuan Tian,Manting Gu,Li Gong
The aim of this study is to further enhance the thermal storage and heat transfer performances of a low-melting-point quinary salt. The eutectic salt was prepared using LiNO3, NaNO3, KNO3, NaNO2, and KNO2as raw materials, followed by the doping of nano-SiO2and nano-MgO into the base salt using a microwave-assisted method. The thermal properties of the samples were analyzed using a Synchronous Thermal Analyzer and a Laser Flash Apparatus. The co-doping of two types of nanoparticles was found to significantly enhance the specific heat capacity of the base salt. The maximum specific heat reached 2.36 J/(g·K), showing a 50.4% increase compared to the base salt. The thermal conductivity of molten salts can be affected by nanoparticles. An observed sample demonstrated a thermal diffusivity of 0.286 mm2/s, indicating a 19.2% improvement over the base salt, which may be attributed to enhanced phonon thermal efficiency. In addition, this study revealed that while interfacial thermal resistance can enhance specific heat capacity, it can also lead to a decrease in the thermal conductivity efficiency of materials. This work can offer insights and references for the enhancement of molten salt properties.
研究领域:
材料科学
·
热能工程
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2022
·
IF 6.633
Changhui Liu,Wenjie Sun,Yixuan Huo,Jiateng Zhao,Zafar Said
Working fluids act as a core role in low-grade thermal energy transportation. Deep eutectic solvent (DES), as a novel environmental solvent, has good stability and environmentally friendly, suitable for a variety of heat exchange environment. It has been emerging in working fluids thanks to superior chemical stability, low vapor pressure and promising rheological properties. While, relatively poor thermal conduction efficiency hinders its practical use. Adding nanoparticles to the DES, which is also coined to be nanofluid, provides a facile way to enhance the thermal conductivity as well as other related thermophysical properties. In this article, glycerol/choline chloride (ChCl) DES based nanofluids were prepared by dispersion of nano-TiO 2 , Fe 2 O 3 , CuO, SiC and carbon. Viscosity and thermal conductivity (TC) were studied comprehensively as functions of testing temperature and mass fraction. The highest thermal conductivity was found to be increased by up to 4.23%. More importantly, specific heat capacity, the other key factor in energy transportation for working fluids were studied with respect to that of nano-additive and temperature, indicates that it could be effectively increased by 26.23% compared to that of pristine base solvent. Mechanistic study by means of a set of experimental ways reveals that hydrogen bond association between DES and nanoparticle is responsible for this specific heat capacity increment.
研究领域:
材料科学
·
热力学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2023
·Vol. 16
·期 21
·6900
·
IF 3.4
Qi Wang,Minghao Fang,Xin Min,Pengpeng Du,Zhaohui Huang,Yangai Liu,Xiaowen Wu,Yulin Liu,Changmiao Liu,Feihui Huang
In recent years, regenerative thermal oxidizer (RTO) has been widely used in the petroleum industry, chemical industry, etc. The massive storage required by solid waste has become a serious problem. Due to their chemical composition, bauxite tailings as raw materials for high-temperature thermal storage ceramics show enormous potential in the fields of research and application. In this study, we propose a method for preparing ferric-rich and high specific storage capacity by adding Fe2O3powder to bauxite tailings. Based on a 7:3 mass ratio of bauxite tailings to lepidolite, Fe2O3powder with different mass fractions (7 wt%, 15 wt%, 20 wt%, 30 wt%, and 40 wt%) was added to the ceramic material to improve the physical properties and thermal storage capacity of thermal storage ceramics. The results showed that ferric-rich thermal storage ceramics with optimal performance were obtained by holding them at a sintering temperature of 1000 °C for 2 h. When the Fe2O3content was 15 wt%, the bulk density of the thermal storage ceramic reached 2.53 g/cm3, the compressive strength was 120.81 MPa, and the specific heat capacity was 1.06 J/(g·K). This study has practical guidance significance in the preparation of high thermal storage ceramics at low temperatures and low costs.Keywords:bauxite tailings;thermal storage ceramic;specific heat capacity;bulk density;RTO
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SOLAR ENERGY MATERIALS AND SOLAR CELLS
·
2024
·
IF 6.3
Meiyang Xu,Gaosheng Wei,Chao Huang,Xiaoze Du
Carbonates have great application potential as heat transfer and thermal energy storage media in the development of future phase change materials. This paper gives thermophysical properties enhancement study on ternary carbonates in liquid state by adding aluminum oxide nanoparticles, multi-walled carbon nanotubes, graphene nanosheets, and experimentally evaluate the performance strengthen ability of multi-dimensional nanoparticles. The thermal diffusivities and specific heats of the prepared samples by the water solution method are determined using the laser flash technique and the differential scanning calorimetry at liquid state, respectively. A thermogravimetric analyzer is deployed for evaluate the high-temperature thermal stability of the composite ternary carbonates. Scanning electron microscopy and Fourier transform infrared spectroscopy techniques are utilized to examine the surface morphologies and chemical structures of the samples. The results indicate that there is a cooperative reinforcement impact on the thermophysical properties of ternary carbonate by utilizing zero-dimensional Al 2 O 3 nanoparticles and two-dimensional graphene nanosheets, with a maximum improvement of 56.7 % for thermal conductivity, and 10.3 % for specific heat, which is apparently larger than adding any single nanoparticle. The composites exhibit superior thermal cycling stability after low-high temperature experiment, and samples can maintain thermal stability until 700 °C in the thermogravimetric analysis.
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
INTERNATIONAL JOURNAL OF THERMOPHYSICS
·
2019
·Vol. 40
·期 11
·1-11
·
IF 0.853
He Yijian,Cao Chao,Xu Jiachen,Sun Yue,Chen Zepeng,Chen Guangming
Aqueous LiCl solutions are typical desiccants. Specific thermal capacity data, covering the temperatures range from 233.15 K to 343.15 K and salt mass fractions ranging from 0.15 to 0.45, have been obtained experimentally. The correlating equation proposed reproduces these experimental data with an average absolute deviation of 0.35 %, and a maximum absolute deviation of 1.15 %. Experimental data from the literature, and theory-based calculations, are reproduced by the new equation with a maximum deviation of 16.13 %, and 10.77 %, respectively.
研究领域:
化学工程
·
热力学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
·
2019
·
IF 4.346
Changhui Liu,Hui Fang,Yu Qiao,Jiateng Zhao,Zhonghao Rao
Deep eutectic solvents (DESs) have gained much attention especially in the fields of catalysis, electrochemistry, material chemistry owing to their low cost, good stability, environmental friendly features. The low vapor, less volatile and wide liquid range properties of DESs inspired us to study their application in the field of heat transfer, especially adopted as a base solvent of nanofluids. In this work, glycerol/choline chloride (ChCl) deep eutectic solvent based nanofluids, by filling with nanoscale TiO 2 , Al 2 O 3 and graphene oxide were demonstrated. Thermal conductivities of the developed nanofluids can be increased by 3–11.4%, and the working temperatures cover from −35 to 275 °C with keeping liquid state. The temperature-dependent viscosities were studied and a little dependence on nanofiller concentration was found in those three different nanofluids. Specific heat capacities of the developed nanofluids were found to be decreased compared with that of base solvent after dispersing nanoparticles. Interestingly, we found that the Al 2 O 3 -filled nanofluid exhibited a unique behavior of thermal conductivity by varying the volume fraction of Al 2 O 3 . 1 H NMR and FT-IR were chosen to study the mechanism of thermal enhancement, which indicated that the hydrogen bond between glycerol and Al 2 O 3 is responsible for this unique phenomenon of heat transfer enhancement.
研究领域:
材料科学
·
热传递工程
·
化学工程
✓ 已验证
DOI
高影响因子
SOLAR ENERGY MATERIALS AND SOLAR CELLS
·
2022
·
IF 7.305
Chen Yan,Junfei Liang,Xiaobin Zhong,Chao Li,Daokun Chen,Zewei Wang,Shuxian Li,Junfeng Xu,Han Wang,Yufeng Li,Yangang Zhang,Hantao Liu
Solar salt is the most commonly used medium for thermal storage and transfer in concentrated solar power (CSP) plants, and the utilization efficiency of solar energy is depended on the thermal properties of solar salt. In this work, atomic-layer-thick hexagonal boron nitride nanosheet (BNNSs, so called white graphene) were obtained and dispersed into solar salt uniformly to produce composites nanofluids . Attributed to the ultra-high thermal conductivity and a large specific surface area of BNNSs, which reduce the thermal resistance , and facilitate forming of more semi-solid boundary layer and nucleation sites , the as-prepared composites nanofluids show superior thermal properties. The properties enhancement mechanism and effects of the mass fraction of BNNSs on the thermal properties of nanofluids was investigated carefully. Compared with the pure solar salt, the solid-phase thermal conductivity , solid-phase and liquid-phase specific heat capacity was elevated by 76.79%, 29.8% and 12.82%, respectively. At the same time, the supercooling degree was significantly decreased from 12.2 °C to 4.7 °C. The enhanced thermal conductivity and specific heat capacity offer significant cost savings, and the reduced supercooling degree prevent phase separation and pipe blockage. Thus, the developed composites nanofluids can be used as a superior medium for CSP plants.
研究领域:
材料科学
·
能源工程
✓ 已验证
DOI
高影响因子
EUROPEAN POLYMER JOURNAL
·
2019
·
IF 3.621
Weilong Chen,Kun Wu,Zhencai Qu,Mangeng Lu
It has been known that phonon mean free path along polymer chains is much larger than in transverse directions because weak interaction between polymer chains leads to chain distortion and entanglement. In order to improve intensity of intermolecular interaction, a series of co-polyesters (CPE) containing different content of offset π-π stacking structure in side chains were synthesized by means of polycondensation and transesterification in this work. WAXD patterns unfolded diffraction peak at 2θ of 27.6°, standing for structure of offset π-π stacking. On enlarging intensity of offset π-π stacking interaction, specific heat capacity of CPE increased from 1.140 Jg −1 K −1 to 1.410 Jg −1 K −1 and thermal diffusivity rose from 0.194mm 2 s −1 to 0.245mm 2 s −1 . As a result, CPE sample exhibited excellent thermal conductivity (TC) of 0.381 Wm −1 K −1 , which is around twice that of traditional thermoplastics. Hence offset π-π stacking interaction could strengthen capacity of heat absorption and thermal conduction at the same time, which might be a good candidate for enhancing thermal conductivity of intrinsic polymers. Furthermore, strong π-π interaction in side chains could maintain modulus when temperature is over glass temperature. And the Young modulus grew from 0.14 GPa to 0.44 GPa with the augment of offset π-π stacking structure.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2022
·
IF 6.633
Wenjie Sun,Qingyi Liu,Jiateng Zhao,Hafiz Muhammad Ali,Zafar Said,Changhui Liu
With the development of electronic machinery, the traditional heat exchange working fluid can no longer be used in some extreme working environments. As a new type of fluid, deep eutectic solvent has the advantages of promising thermal stability, low cost and non-toxicity through the hydrogen bond association of hydrogen bond acceptor and hydrogen bond donor, and is also coined to be an efficient heat transfer working fluid. In this work, three kinds of nanofluids filled with TiO 2 , Al 2 O 3 and Fe 2 O 3 nanoparticles were prepared with glycerol/sodium acetate trihydrate deep eutectic solvent as the base solution, and the mechanism of thermal conductivity change of nanofluids were discussed from atomic and microscopic levels. The experimental results showed that the prepared glycerol/ sodium acetate trihydrate 2:1 deep eutectic solvent system reduced the viscosity by 58.03% compared with glycerol, and increased the thermal conductivity by 17.2% compared with glycerol at 25 ℃. The effects of nanoparticles on thermal conductivity and specific heat capacity were also investigated. Compared with deep eutectic solvent, the thermal conductivity was improved after adding Fe 2 O 3 nanoparticles; it is worth noting that the specific heat capacity of nanofluids was more than doubled after adding nanoparticles.
研究领域:
材料科学
·
热力学
·
能源工程
✓ 已验证
产品关联
DOI
高影响因子
Case Studies in Thermal Engineering
·
2023
·
IF 6.8
Jing Fan,Dazhi Gao,Fenhong Song
Deep eutectic solvents are now widely used in metal electrochemical deposition, biomass catalysis and material synthesis because of their advantages of greenness, low cost, good biocompatibility and biodegradability, and it is proved that DESs have great potential for its utilization as heat transfer fluids. In this work, eight DESs were prepared by thermal method using choline chloride as the hydrogen bond acceptor and glycerol, polyethylene glycol 600, lactic acid and o-cresol as the hydrogen bond donor. Based on the flow calorimetry method, the specific heat capacity system was established and its reliability and precision were verified by measuring the specific heat capacity of deionized water. The maximum deviation of the experimental value and the standard value under the pressure 101 kPa was 2.03%, and the average absolute deviation was 1.01%, and the repeatability was less than 1.5%. Then, the densities and the constant pressure specific heat capacities of eight DESs in the temperature range of 293 K–353 K and 293 K–373 K were measured respectively. The experimental results could support for the scale utilization of DESs.
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
THERMOCHIMICA ACTA
·
2016
·
IF 1.938
X.K. Gao,X. Wen,H. Zhou,Q. Zhu,J.L. Wang,X.Y. Li
In this work, a novel and simple method was put forward to measure the isobaric specific heat capacity for the kerosene RP-3 with a flow-calorimeter at the conditions of high temperature and high pressure. Based on the energy conservation principle, the formula for heat capacity was derived and its measurement was realized by the convective mixing method between the hot and cold fuel. Taking the precision of the instrument and the error transfer into account, the relative expanded uncertainty of this method was acquired of about ± 6.38% (coverage factor k = 2). Meanwhile, the accuracy and reliability were verified by the standard material of water and n -decane. In the temperature range from (296.2–719.0) K and under pressure range from (2.4–4.0) MPa, the measurement for the kerosene RP-3 was carried out and the experimental observations were compared and agreed well with the published data. At last, an empirical correlation relationship of heat capacity due to the temperature and pressure was presented by using Garg’s model with the measured experimental data.
研究领域:
物理化学
·
能源工程
✓ 已验证
DOI
高影响因子
REACTIVE & FUNCTIONAL POLYMERS
·
2019
·
IF 3.074
Weilong Chen,Kun Wu,Bingfei Nan,Mangeng Lu
Thermal conductivity (TC) of polymers can be enhanced by incorporating rigid conjugated structures, which will result in sacrifice of other characteristics such as flexibility. To deal with such problem, a series of polyesters (PEmC) with long methylene units in main chains were synthesized by polycondensation and transesterification . A sharp increment of 219.7% in TC was observed and the maximum TC reached to 0.227 Wm −1 K −1 , which is twice that of traditional thermoplastic . It is intriguing that thermal diffusivity for above samples changed few while specific heat capacity of PEmC increased from 0.620 J g −1 K −1 to 1.470 J g −1 K −1 on elongating the length of flexible methylene segments in main chains. Thus TC in this system was mainly enhanced by enhancing specific heat capacity. Due to flexible segments in main chains, Young modulus of PEmC (around 0.2 GPa) is one order of magnitude lower than that of conventional thermoplastic. Moreover, PEmC exhibited good performance both in maintaining flexibility below glass-transition temperature and preserving modulus above glass-transition temperature, which might be remarkable in potential application for flexible electronics.
研究领域:
材料科学
·
高分子化学
✓ 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）