scholarly journals The Development of SF6 Green Substitute Gas

2021 ◽  
Vol 13 (16) ◽  
pp. 9063
Author(s):  
Tao Jiang ◽  
Xiangzhao Meng ◽  
Qiming Wei ◽  
Lijun Jin ◽  
Yanjun Sun

Due to its high greenhouse effect, the use of SF6 as the main insulating gas is restricted in the electric power field. Along with the aim of environmental protection, the search for new alternative gases with a lower greenhouse effect and higher insulation strength has received a lot of attention. The properties of alternative gases have a vital impact on the performance of medium-voltage power distribution equipment. Firstly, based on the existing liquefaction temperatures of SF6/N2, SF6/CO2, and SF6/CF4, the calculated liquefaction temperatures were expanded to 0.7 MPa. Combining the Antoine vapor-pressure equation and the basic law of vapor–liquid balance, the vapor pressures of SF6/N2, CF3I/N2, c-C4F8/N2, C4-PFN/N2, C4-PFN/CO2, and C5-PFK/CO2 were obtained. Secondly, the critical breakdown field strength was analyzed for C4-PFN/CO2, C5-PFK/CO2, SF6, CF3I/N2, C5-PFK/Air, and c-C4F8/N2. Finally, the GWPs of SF6/N2, C4-PFN/N2, C4-PFN/CO2, C5-PFK/CO2, and C5-PFK/N2 were discussed. The results show that the liquefaction temperature gradually decreases as the pressure rises; SF6/N2 has the highest vapor pressure at −5 °C; the critical breakdown field strengths of several mixtures are higher than that of SF6.

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1596
Author(s):  
Peng Zhang ◽  
Yongqi Zhang ◽  
Xuan Wang ◽  
Jiaming Yang ◽  
Wenbin Han

Blending thermoplastic elastomers into polypropylene (PP) can make it have great potential for high-voltage direct current (HVDC) cable insulation by improving its toughness. However, when a large amount of thermoplastic elastomer is blended, the electrical strength of PP will be decreased consequently, which cannot meet the electrical requirements of HVDC cables. To solve this problem, in this paper, the inherent structure of thermoplastic elastomer SEBS was used to construct acetophenone structural units on its benzene ring through Friedel–Crafts acylation, making it a voltage stabilizer that can enhance the electrical strength of the polymer. The DC electrical insulation properties and mechanical properties of acetylated SEBS (Ac-SEBS)/PP were investigated in this paper. The results showed that by doping 30% Ac-SEBS into PP, the acetophenone structural unit on Ac-SEBS remarkably increased the DC breakdown field strength of SEBS/PP by absorbing high-energy electrons. When the degree of acetylation reached 4.6%, the DC breakdown field strength of Ac-SEBS/ PP increased by 22.4% and was a little higher than that of PP. Ac-SEBS, with high electron affinity, is also able to reduce carrier mobility through electron capture, resulting in lower conductivity currents in SEBS/PP and suppressing space charge accumulation to a certain extent, which enhances the insulation properties. Besides, the highly flexible Ac-SEBS can maintain the toughening effect of SEBS, resulting in a remarkable increase in the tensile strength and elongation at the break of PP. Therefore, Ac-SEBS/PP blends possess excellent insulation properties and mechanical properties simultaneously, which are promising as insulation materials for HVDC cables.


1964 ◽  
Vol 37 (1) ◽  
pp. 210-220 ◽  
Author(s):  
R. B. Spacht ◽  
W. S. Hollingshead ◽  
H. L. Bullard ◽  
D. C. Wills

Abstract Comparable volatility data are presented for three phenolic and five aromatic amine compounds. Vapor pressure curves for the materials are given along with the vapor pressure equations derived from these curves. The equations are used to calculate temperatures at which the eight compounds would have equal vapor pressure. Vapor pressures of each material are calculated at specified temperatures. Data are given for several methods of determining actual losses of antioxidants at several different temperatures and at several different airflows. Surface effects are also studied. In general, all methods give the same relative rating of the eight materials, but quantitative data vary considerably with the method used.


1989 ◽  
Vol 167 ◽  
Author(s):  
S. Jeng ◽  
M. Xu ◽  
P. L. Liu ◽  
H. S. Kwok ◽  
C. J. Lee

AbstractPolyimides are finding increased use as dielectric materials in multi-level metallization technology, which is the key to high-density packaging applications for microelectronics.Newly developed photosensitive polyimidesiloxane (SIM2000XL-RTS) has been evaluated in terms of thermal stability, photosensitivity and lithography as well as dielectric breakdown properties. The sensitivity to N2 laser exposure has been measured under optimized process conditions. We also find that SIM2000XL-RTS can be processed up to 350°C without significant decomposition. Micron-scale contact images can be successfully patterned by both N2 laser and conventional UV lamp exposure. The dielectrical breakdown field strength of SIM2000XL-RTS is about 4 MV/cm by sandwich measurements.


Sign in / Sign up

Export Citation Format

Share Document