Article
Thermodynamics
Azhar K. Mohammed, Idres A. Hamakhan
Summary: The study shows that using solar water heating systems can significantly reduce energy consumption, leading to substantial savings in electricity usage and reduction in CO2 emissions for households in the Kurdistan region.
CASE STUDIES IN THERMAL ENGINEERING
(2021)
Article
Chemistry, Multidisciplinary
Sittichai Wangwiwattana, Koike Yoshikazu
Summary: This research investigates the contact heating mechanism that causes electrical fires and finds that contact surfaces made of copper or copper alloys may have a higher risk of starting an electrical fire than other materials when specific arcing conditions are met.
APPLIED SCIENCES-BASEL
(2022)
Article
Construction & Building Technology
Haiyan Yan, Lulu Yang, Mengru Dong, Bo Hu, Zhen Sun, Fangning Shi, Guodong Yuan, Xiaofang Bi
Summary: This study compared the thermal comfort of two common heating terminals, BRH and FH, in urban residential buildings in cold areas of China. The results showed that FH terminals have significantly higher mean radiant temperature and operative temperature, leading to increased acceptance of low-temperature environment among occupants.
JOURNAL OF BUILDING ENGINEERING
(2022)
Article
Chemistry, Physical
Zelong Wang, Yanan Zhang, Jungang Yi, Ning Cai, Jia Guo
Summary: Heat accumulation is a critical issue in the development of miniaturized, high-power density, and highly integrated electronic devices. The study introduces the development and characterization of highly thermally conductive yet electrically insulating Cu@Al2O3/epoxy composites, highlighting their potential application in thermal management.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Thermodynamics
Matthias Berger, Benjamin Schroeteler, Helene Sperle, Patrizia Puentener, Tom Felder
Summary: This study assesses the potential application of thermal energy storage technologies on a residential scale through a performance analysis of photovoltaic and solar thermal generation combined with energy storage systems. The results demonstrate that these technologies can significantly increase energy self-sufficiency and are competitive without subsidies, providing guidance for the future development and design of thermal energy storage.
Article
Materials Science, Multidisciplinary
Zelong Wang, Dajun Hou, Jungang Yi, Ning Cai, Jia Guo
Summary: In this study, barium titanate coated Cu core-shell particles were prepared and used as thermal conductive fillers to enhance the thermal conductivity of epoxy matrix, achieving a 580% increase at a loading of 10 vol%. The composites also showed high electrical insulation due to the insulative BaTiO3 layer on the Cu surface. This research provides a new perspective on the design of functionalized core-shell thermal conductive fillers for high-performance thermal interface materials.
Article
Nanoscience & Nanotechnology
S. Q. Li, Q. H. Li, H. J. Cao, X. Z. Zheng, Z. H. Zhang
Summary: In this study, the performance of SnBi solder was improved by adding Cu@Ag core-shell particles, resulting in significant refinement in grain size and intragranular eutectic structures. The modified solder exhibited a shift from brittle fracture mode to a mixed brittle and tough mode, and a 21% increase in tensile strength. Furthermore, the addition of Cu@Ag core-shell particles significantly increased electrical conductivity by forming interconnected high-speed channels for electron migration, and remarkably enhanced thermal conductivity with a value of 41.33 W m-1 K-1. This research addresses the partial property deficiencies of SnBi solder and expands its application in low temperature electronic packaging.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Physics, Applied
T. Vazquez, P. Teulet, F. Valensi, A. Risacher, M. Masquere
Summary: A systematic study on arc faulting between two cables in aeronautic conditions was conducted, with a focus on power balance of the arc, electrical characteristics, and radiative heat flux. The study highlighted the effects of current mode, cable material, and pressure on the power balance, revealing insights such as the power transferred to the cables and the power lost through radiation, conduction, and convection in the arc column. Additionally, optical emission spectroscopy measurements were used to determine the overall temperature of the arc, showing that copper-contaminated plasma has a higher overall temperature compared to aluminium-contaminated plasma, and suggesting that DC and lighter aluminium-based cables result in higher power.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2021)
Article
Engineering, Aerospace
Pau Bas-Calopa, Jordi-Roger Riba, Juan Antonio Ortega
Summary: Strict regulations have been issued to limit CO2 emissions and improve efficiency for new aircraft. To meet these regulations, future aircraft will use more electrical power, leading to higher distribution voltage levels. However, this increase in voltage levels can cause new failure modes and risks of insulation failure due to electrical discharges. This paper presents a strategy using image sensors to detect and quantify electrical discharges in aircraft environments, contributing to predictive maintenance and aircraft safety.
Article
Thermodynamics
Jing Zhang, Guofeng Su, Tao Chen, Changzheng Li, Wenzhong Mi
Summary: Glowing contact caused by poor electrical contacts is a common source of heat. A fire incident demonstrates that the glowing phenomenon persisted for 8 hours before flashover. Therefore, it is crucial to investigate the electrical fire risks and fire mechanisms related to glowing contact. This research measures the temperature distribution of the glowing contact, proposes a finite element-based heat transfer model for glowing contact, and carries out experiments on the thermal hazards exerted by glowing contact on insulation layers. The results confirm the consistency between the proposed model and the experimental data, revealing that the temperature and overheating range increase as the oxide bridge forms and that physical or arc shorts can be triggered by bared copper conductors or carbonized insulations caused by glowing contact, leading to electrical fires.
CASE STUDIES IN THERMAL ENGINEERING
(2023)
Article
Automation & Control Systems
Baiyang Liu, Xiangjun Zeng
Summary: This article proposes an arc model based on electric-to-thermal energy conversion, which can simulate the whole development process of continuous arc faults in a 220-V power supply system. A computation method is also proposed based on the nonsmooth connections of the measured voltage waveform. Experimental results validate the generality and effectiveness of the arc model and computation method for the 220-V power supply system.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2023)
Article
Engineering, Electrical & Electronic
Chulmin Park, Kiwon Lee, Kinam Kim, Hunyoung Lim, Young Park
Summary: This paper examines the techniques for quantitatively detecting arc flash caused by electrical faults. The system for detecting the time when an arc flash occurs and the techniques for calibrating this system were analyzed. A field test was conducted to detect the arc flash caused by mechanical non-contact between the pantograph and the catenary of electric railway vehicles. In the field test, 9 arc flashes were detected using the percentage technique for quantitative detection. The technique of detecting the time when an arc flash occurs is a new quantitative evaluation method, which is expected to be widely used for preventing negligent accidents in the electrical field and determining the presence of harmful arcs in real time.
JOURNAL OF ELECTRICAL ENGINEERING & TECHNOLOGY
(2023)
Article
Chemistry, Physical
Xiaojing Li, Peng Hu, Jinshu Wang, Shuqun Chen, Wenyuan Zhou
Summary: A new one-step thermal plasma synthesis route was developed to construct core-shell W-Cu nanoparticles with size about 30 nm, addressing the issues of homogeneous elemental distribution and short diffusion distance for Cu to form network around W grains. The synthesized nanocomposite powders facilitated fast densification with uniform microstructure and suppressed W grain growth, resulting in a compact with high relative density and hardness.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Materials Science, Multidisciplinary
Yunfan Dong, Jinfeng Leng, Binghui Ren, Xianglei Xu, Changpeng Xia
Summary: The core-shell structured composite with graphene coating inhibits dendritic Cr phase formation and increases the number of dispersed equiaxed grains, leading to improved properties of CuCr electrical contact materials.
Article
Energy & Fuels
Mohamad Aramesh, Bahman Shabani
Summary: By integrating a selected PCM within the structure of an evacuated tube solar hot water system, a novel PCM-based self-storing design is proposed. This design can maintain the collector output temperature at around 63 degrees C after 15 h of not receiving any sunlight, while the output temperature of the normal collector drops down to ambient temperature in the same period. The obtained energy storage efficiency is 57% and 75%, and overall thermal efficiency is 49% and 72%, for the normal and the self-storing collectors, respectively. For the smallscale system used in this study, the proposed design helps reduce the size of the hot water storage tank required to supply the hot water demand by 55%.
JOURNAL OF ENERGY STORAGE
(2023)