GEOTHERMICS
·
2019
·
IF 3.47
Xianzhi Song,Rui Zheng,Ruixia Li,Gensheng Li,Baojiang Sun,Yu Shi,Gaosheng Wang,Shijie Zhou
In the exploitation of geothermal resources, geothermal single-well heat extraction technology can realize geothermal development without extracting water, which has a wide application prospect. The single-well heat extraction relies on heat conduction between wellbore and reservoir, and heat convection between wellbore and reservoir water. Therefore, the thermal resistance between wellbore and reservoir is an important factor affecting performance of heat extraction. Employing cement with thermal conductive materials in the thermal recovery section of geothermal reservoir is an effective method to enhance heat extraction performance. The study presents a method of producing thermal conductive cement by mixing oil well cement with thermal conductive materials, including graphite, ferrum and copper. Then thermal conductivity and compressive strength tests are carried out, and the influence of thermal conductive material exerted on the thermal conductivity of cement paste is studied. Moreover, relations between porosity and thermal conductivity of cement paste, and relations between particle continuity and thermal conductivity of cement paste are studied by porosity test and SEM scanning. The study demonstrates that with graphite increases, the porosity of cement paste decreases firstly and then increases, and the thermal conductivity of cement paste increases firstly and then decreases; With ferrum increases, the porosity of cement paste decreases, and the thermal conductivity of cement paste increases; With copper increases, the porosity of cement paste decreases, and the thermal conductivity of cement paste increases; As the temperature rises, the thermal conductivity of cement paste decreases gradually; Thermal conductive materials can enhance thermal conduction in cement, and pore would provide thermal insulation; On the condition of improve thermal conductivity, cement with 0.05-0.15 graphite, cement with 0.05-0.20 ferrum and cement with 0.05-0.20 copper can meet requirements. The results of this study provide theoretical guidance for improving the thermal conductivity of cement in geothermal well.
研究领域:
土木工程
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
Micromachines
·
2022
·Vol. 13
·期 11
·1949
·
IF 3.523
Chao Chang,Yaoguang Yang,Lilin Pei,Zhaoyang Han,Xiu Xiao,Yulong Ji
With the rapid development of electronic technologies towards high integration, high power and miniaturization, thermal management has become an increasingly important issue to guarantee the reliability and service life of electronic devices. The oscillating heat pipe (OHP), which was governed by thermally excited oscillating motion, was considered as a promising technology to dissipate high-density heat and had excellent application prospects in many important industrial processes. A flat-plate OHP, however, was fabricated by traditional welding methods, which were difficult and inefficient, resulting in increasing the cost and wasting the production time. In this work, we adopted a new metal 3D printing technology to develop an aluminum flat-plate OHP, which made it facile to build complex inner channels with high-precision molding at one time. AlSi10Mg powders, as raw materials, were selectively melted and solidified to form the container of the flat-plate OHP. The sintered inner surface presented excellent wettability to the working fluid, which facilitated the evaporation of the working fluid. Acetone was chosen as the working fluid, and the filling ratios with a range of 40–70% were loaded into the flat-plate oscillating heat pipe to analyze its effect on heat transfer performance. It was found that the 3D-printed flat-plate OHP with a 60% filling ratio had a better heat transfer performance and a lower thermal resistance, and it was able to work properly in both vertical and horizontal operation modes. The 3D-printed flat-plate OHP had been successfully applied for the thermal management of high-power LEDs, and the results showed that the temperature of LEDs was maintained within 60 °C, and its service life was prolonged.Keywords:3D printing;oscillating heat pipe;thermal resistance;heat transfer performance
研究领域:
电子工程
·
热管理技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2021
·Vol. 28
·期 36
·50500-50509
·
IF 4.223
He Qian,Huang Shengxiong,Luo Wei,Su Yifeng,Xia Mao,Zhou Nan,Zhou Zhi
In-situ catalytic pyrolysis has simple process configuration and low cost. Ex-situ catalytic pyrolysis can optimize the pyrolysis capacity and upgrade catalysis, and the catalytic can be reused. But there have been few studies researched on compare in-situ and ex-situ catalytic pyrolysis of the OS performed in similar reactor with two kinds of catalytic. This paper study the pyrolysis of oily sludge (OS) uses CaO and oily pyrolysis char as catalytic at 700 °C. Through analysis the pyrolysis oil (PO), pyrolysis solid (PS) and pyrolysis gas (PG) during pyrolysis procedure to research the difference between in-situ and ex-situ catalytic pyrolysis. The gas chromatography-mass spectrometry (GC-MS) results show that CaO was conducive to the synthesis of aromatics, which content more than aliphatics and heterocyclics in CaO-i (i: in-situ) and CaO-e (e: ex-situ) groups. However, char greatly inhibits the production of aromatic compounds and promotes the production of aliphatic compounds. Gas chromatography (GC) results present that the char and CaO can greatly increase the content of combustible gas and the content reach to 85.85%, the pyrolysis gas (PG) keep at the highest combustion performance in char-CaO-i group. Meanwhile, compared with uncatalyzed groups, the content of CH 4 and CO increased about 2.05% and 3.93%, respectively. Fourier transform infrared spectroscopy (FT-IR) show that char and CaO reduce the function groups number of pyrolysis solid (PS), and it shows that the pyrolysis reaction is more complete. This research is expecting to provide theory support for catalytic pyrolysis of OS.
研究领域:
环境科学
·
能源工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Yingchun Liu,Zhaoson Hu,Haohan Wu,Shiron Sun,Liheng Chen,Kun Wu,Xuliang Lin,Yanlin Qin
Developing high-performance thermal management materials with continuous thermal conductive networks (TCN) and low interface thermal resistance (ITR) remains challenging for heat dissipation of modern electronics. Here, a multiscale BN modulation strategy for preparing dense TCN of polymer composites and decreasing simultaneously the ITR is demonstrated. As a result, the composites in this system show further thermal conductivity (κ) enhancement (25.1%) compared with single kinds of filler systems, promoting the κ of neat polymer by ∼9 times (1.957 W m −1 K −1 ), and showing a relatively high κ enhancement (∼800%). Based on the experimental and theoretical simulation results, the ITR decreased by ∼25% compared to that of conventional mixed systems, which is in accordance with κ enhancement results, indicating this method can enable efficient interconnection of fillers and dense TCNs. Meanwhile, it also presents superior dielectric properties (the dielectric constant and loss are 3.17 and 0.018, respectively.) and thermal stability (char yield is up to 72.70%, T HRI is >269 °C.). This work provides valuable guidance for designing efficient TCN in composites and demonstrates their potential application in electronic packaging and thermal management of electronics.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Xing Yang,Jun Guo,Zi-Yuan Wang,Wen-Hao Gu,Quan Shan,Jing Feng,Zhen-Hua Ge
Bi 2 S 3 -based materials with low thermal conductivity and high Seebeck coefficient has been regarded as promising thermoelectric materials for years. To optimize the thermoelectric properties of Bi 2 S 3 materials, (Se, Cl)-co-doped nanostructured Bi 2 S 3 bulks were prepared by hydrothermal method combined with spark plasma sintering . The doping contents of Se and Cl in Bi 2 S 3 depend on the reaction time of the hydrothermal process. A high power factor of 450 μWm −1 K −2 was achieved for Bi 2 S 3 sample with the reaction time of 24 h owing to the substitution of S by Se and Cl. Meanwhile, a low thermal conductivity of 0.35 Wm −1 K −1 is obtained for the Bi 2 S 3 sample with the reaction time of 18 h, owing to the strong phonon scattering caused by the high density of grain boundaries, pores and point defect . Therefore, benefiting from the improved electrical transport properties and reduced thermal conductivity, a peak ZT value of ~ 0.57 was obtained at 673 K for the Bi 2 S 3 sample with the reaction time of 24 h.
研究领域:
材料科学
·
热电材料
✓ 已验证
产品关联
DOI
高影响因子
Polymers
·
2023
·Vol. 15
·期 2
·414
·
IF 5
Zhaoyang Han,Chao Chang
As flexible electronic technologies rapidly developed with a requirement for multifunction, miniaturization, and high power density, effective thermal management has become an increasingly important issue. The oscillating heat pipe, as a promising technology, was used to dissipate high heat fluxes and had a wide range of applications. In this paper, we reported the fabrication and heat transfer performance evaluation of a polymer-based flexible oscillating heat pipe (FOHP) prepared using 3D printing technology. The 3D-printed inner surface presented excellent wettability to the working fluid, which was beneficial for the evaporation of the working fluid. Ethanol was selected as the working fluid, and the influence of the filling ratios range of 30–60% on heat transfer performance was analyzed. It was found that a 3D-printed FOHP with a filling ratio of 40% presented the best heat transfer performance with the lowest thermal resistance, and the fabricated heat pipes could be easily bent from 0° to 90°. With the best filling ratio, the thermal resistance of the FOHPs increased with larger bending angles. In addition, the 3D-printed FOHP was successfully applied for the thermal management of flexible printed circuits, and the results showed that the temperature of flexible printed circuits was kept within 72 °C, and its service life was guaranteed.Keywords:3D printing;flexible oscillating heat pipe;thermal resistance;thermal performance
研究领域:
热管理技术
·
材料科学与工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Energy Storage
·
2022
·
IF 8.907
Sebastiano Tomassetti,Alessia Aquilanti,Pio Francesco Muciaccia,Gianluca Coccia,Christoph Mankel,Eduardus A.B. Koenders,Giovanni Di Nicola
The increasing use of renewable energy sources has highlighted the importance of energy storages, and in particular of latent heat thermal energy storages (LHTESs). Among the phase change materials (PCMs) that can be used in such systems, sugar alcohols (SAs) are considered potential substances that may lead to interesting applications in the LHTES sector. In this work, a detailed literature review analysis of six SAs (xylitol, sorbitol, erythritol, mannitol, inositol, dulcitol), their thermophysical properties, their thermal stability and their main LHTES applications is presented for the first time. The thermophysical properties under discussion include melting and crystallization temperatures , latent heats of melting and crystallization, specific heat, thermal conductivity , density and dynamic viscosity . Thermal stability was evaluated by taking into account studies of thermal endurance, degradation temperature and cycling stability. Differential scanning calorimetry (DSC), T -history, Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) were considered as measurement techniques. Applications include the use of SAs in solar collectors and cookers, heat exchangers , porous materials, absorption cooling systems, mobilized thermal energy storages (M-TESs). New measurements of phase transition properties and degradation temperature for the studied SAs were also carried out by the authors of the present study. A good agreement between the proposed data and the literature values was found. The analysis reveals that some SAs may be considered suitable for low-to-medium temperature LHTES applications, provided that their drawbacks are adequately evaluated and addressed. To this purpose, the study also highlights the most critical aspects that should be considered when developing both fundamental research and engineering applications related to SAs.
研究领域:
能量存储
·
热能工程
·
材料科学
·
可再生能源
✓ 已验证
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2025
·
IF 19
Liangyuan Qi,Wei Cai,Tianyang Cui,Junwei Li,Lei Song,Zhou Gui,Bin Fei,Jixin Zhu,Yuan Hu,Weiyi Xing
Radiative cooling coatings demonstrate broad applicability on equipment surfaces, spanning spacecraft to precision instruments, for sub-ambient cooling. However, unlike conventional equipment relies on solar reflection and infrared emission for cooling, the heat-generating equipment relies on coupled thermal conduction and radiative cooling, representing a distinct heat transfer paradigm. This study introduces an innovative fire-safe radiative cooling-enhanced anisotropic thermal rectification coating (TRC) by leveraging the thermal rectification effect. The rectification mechanism stems from engineered thermal conductivity gradients with temperature-dependent anisotropy, where asymmetric phonon transport in multilayer architectures enables unidirectional heat flux control. Through the rational coupling of radiative cooling emitters at the cold terminal with thermal diodes, the TRC achieves unidirectional heat transfer enhancement through conduction-radiation coupling, demonstrating a thermal rectification coefficient of 1.78 and 3.1–3.4 °C daytime temperature reduction below ambient. Crucially, under concurrent solar irradiation and simulated heat-generating equipment (50 °C), TRC attains 6.8 °C maximum cooling enhancement. Notably, the TRC integrates gas-phase and condensed-phase flame retardant mechanisms to effectively mitigate the risk of thermal runaway in heat-generating devices. This multifunctional integration advances radiative cooling technology toward practical implementation in thermal-critical infrastructure, including power electronics thermal management and smart building systems.
研究领域:
热工程
·
材料科学
·
传热学
·
纳米技术
·
消防安全工程
·
应用物理学
✓ 已验证
产品关联
DOI
高影响因子
THERMOCHIMICA ACTA
·
2024
·
IF 3.1
Desheng Chen,Ke Liu,Zixin Ye,Gao Zhang,Jinxin Xu,Dongfang Hu,Jiong Ding
The accelerating rate calorimeter is a commonly used tool for evaluating thermal hazards. Due to the thermal inertia, the heat dissipation between the reaction system and the furnace, the pure adiabatic condition cannot be achieved. This leads to inaccurate thermodynamic and kinetic results. To systematically study and correct this heat dissipation, numerical simulations and experiments were carried out to investigate the main heat dissipation path and the factors. The results show that convection is the main heat dissipation pathway. The dynamic characteristics of the thermocouple and sidewall have different effects on reactions with different self-heating rates. In addition, a heat dissipation correction method based on the heat transfer model is proposed and validated by simulations and experiments. The simulation and experimental results both show the effectiveness of this correction method. These mean it has a certain significance for the improvement of the accelerating rate calorimeter experimental data processes.
研究领域:
化学工程
·
热力学
·
安全科学
✓ 已验证
产品关联
DOI
高影响因子
Energy & Environmental Science
·
2024
·
IF 32.4
Yinghong Xu,Zhiwei Li,Simin Li,Shengliang Zhang,Xiaogang Zhang
Thermodiffusion-based thermoelectrochemical cells have become one of the promising candidates for self-power supply by efficiently harvesting low-grade heat. However, fulfilling continuous energy output is still challenging because of the non-reciprocating motion of cations and anions during diffusion by adopting a steady heat source. Herein, we propose a moderate-concentration phase-change electrolyte for tuning the thermodiffusion process and the thermopower. Interestingly, the dominant ion can be alternated between cations and anions only by operando regulation of the physical state of the as-designed electrolyte, enabling the reversible polarization of devices from the p-type to the n-type with a tunable thermopower from 3.2 to −2.1 mV K−1. Moreover, the correlation of phase transition behaviors, solvation structures, and thermoelectrochemical performances is investigated. As a proof-of-concept, a prototype module consisting of n-type and p-type units connected in series displays high sensitivity and stability for long-term power generation under light irradiation, demonstrating the potential of phase-change electrolytes in energy-related applications.
研究领域:
材料科学
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
Nature Communications
·
2022
·Vol. 13
·期 1
·1-8
·
IF 17.694
Li Ming-Ding,Shen Xiao-Quan,Chen Xin,Gan Jia-Ming,Wang Fang,Li Jian,Wang Xiao-Liang,Shen Qun-Dong
With speeding up development of 5 G chips, high-efficient thermal structure and precise management of tremendous heat becomes a substantial challenge to the power-hungry electronics. Here, we demonstrate an interpenetrating architecture of electrocaloric polymer with highly thermally conductive pathways that achieves a 240% increase in the electrocaloric performance and a 300% enhancement in the thermal conductivity of the polymer. A scaled-up version of the device prototype for a single heat spot cooling of 5 G chip is fabricated utilizing this electrocaloric composite and electromagnetic actuation. The continuous three-dimensional (3-D) thermal conductive network embedded in the polymer acts as nucleation sites of the ordered dipoles under applied electric field, efficiently collects thermal energy at the hot-spots arising from field-driven dipolar entropy change, and opens up the high-speed conduction path of phonons. The synergy of two components, thus, tackles the challenge of sluggish heat dissipation of the electroactive polymers and their contact interfaces with low thermal conductivity, and more importantly, significantly reduces the electric energy for switching the dipolar states during the electrocaloric cycles, and increases the manipulable entropy at the low fields. Such a feasible solution is inevitable to the precisely fixed-point thermal management of next-generation smart microelectronic devices.
研究领域:
材料科学
·
电子工程
·
热能工程
·
纳米技术
✓ 已验证
DOI
PubMed
高影响因子
Sustainable Cities and Society
·
2018
·
IF 3.073
Li Yang,Xiaoling Cao,Nan Zhang,Bo Xiang,Zhaoli Zhang,Bin Qian
The thermal reliability of phase change materials (PCMs) is an important factor for the successful application of latent heat thermal energy storage. In this work, 10,000 thermal cycles have been firstly carried out to investigate the thermal reliability of four typical fatty acids (lauric acid, myristic acid, palmitic acid and stearic acid) as PCMs. The thermal properties before and after cycles were tested by differential scanning calorimeter. It was found that with increasing number of thermal cycles, both the phase transition temperature and the latent heat tended to decrease. In the experiment, the maximum change in the melting temperature was −0.37 °C and change rate of latent heat was −7.57%. The freezing temperature decreased obviously with increasing number of thermal cycles, which led to a maximum increase of 4.15 °C in the degree of supercooling. In addition, the specific heat and thermal conductivity of the PCMs after 10,000 thermal cycles had no significant change. FT-IR showed that the chemical structure of fatty acids had not changed after thermal cycles. The experimental results showed that these fatty acids can function as admirable PCMs with high thermal reliability for long-term applications.
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
危险品化学品经营许可证（带存储）