Heat Transfer Analysis of Different Conditions for SF /N 2 Gas-Insulated Transmission Lines

• Published in: IEEE transactions on power delivery Vol. 36; no. 2; pp. 831 - 840
• Main Authors: Qiao, Yu Jiao, Liang, Rui, Gao, Peng, Zhu, Si Yao, Chen, Chun Yu, Qin, Yu Xuan, Tang, Xiao Zheng
• Format: Journal Article
• Language: English
• Published: IEEE 01.04.2021
• Subjects: Conductors; different conditions; finite-element method; Gas insulated transmission lines; gas insulation; heat transfer; Heating systems; Insulators; Mathematical model; SF<inline-formula xmlns:ali="http://www.niso.org/schemas/ali/1.0/" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"> <tex-math notation="LaTeX"> _{6}</tex-math> </inline-formula>/N<inline-formula xmlns:ali="http://www.niso.org/schemas/ali/1.0/" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"> <tex-math notation="LaTeX"> _2</tex-math> </inline-formula> gas mixtures; Temperature
• ISSN: 0885-8977; 1937-4208
• DOI: 10.1109/TPWRD.2020.2994928

Considering that SF<inline-formula><tex-math notation="LaTeX">_6</tex-math></inline-formula> is a potent greenhouse gas, SF<inline-formula><tex-math notation="LaTeX">_{6}</tex-math></inline-formula>/N<inline-formula><tex-math notation="LaTeX">_2</tex-math></inline-formula> gas mixtures are preferred to serve as the insulating gas for its environmental friendliness and good insulation. Since heat transfer analysis is very useful for ascertaining the appropriate temperature rise range, which can ensure the safe operation and extension of remaining useful life of GIL, it is essential to study the thermal properties of SF<inline-formula><tex-math notation="LaTeX">_{6}</tex-math></inline-formula>/N<inline-formula><tex-math notation="LaTeX">_2</tex-math></inline-formula> gas mixtures. Nevertheless, very few studies investigate on the temperature field of SF<inline-formula><tex-math notation="LaTeX">_{6}</tex-math></inline-formula>/N<inline-formula><tex-math notation="LaTeX">_2</tex-math></inline-formula> gas mixtures under ideal conditions. To reflect the heat transfer characteristics accurately, in this paper, by using the finite-element method and multi-physics coupling, the heat transfer properties in the GIL is analyzed by using a three-dimensional (3-D) axisymmetric GIL model. By varying the SF<inline-formula><tex-math notation="LaTeX">_{6}</tex-math></inline-formula>/N<inline-formula><tex-math notation="LaTeX">_2</tex-math></inline-formula> mixing ratio and observing the corresponding heat transfer characteristics, the mapping between SF<inline-formula><tex-math notation="LaTeX">_{6}</tex-math></inline-formula>/N<inline-formula><tex-math notation="LaTeX">_2</tex-math></inline-formula> mixing ratio and the temperature rise is obtained by using the model. Furthermore, the mappings are studied under different gas pressures, line currents and ambient temperatures, which correspond to different real-life operating conditions. The proposed strategies can effectively give guidance of choosing proper SF<inline-formula><tex-math notation="LaTeX">_{6}</tex-math></inline-formula>/N<inline-formula><tex-math notation="LaTeX">_2</tex-math></inline-formula> mixing ratio for desired temperature rise, and thus having great values of practical applications.