Compositions, thermodynamic properties, and transport coefficients of high-temperature C5F10O mixed with CO2 and O2 as substitutes for SF6 to reduce global warming potential
Compositions, thermodynamic properties, and transport coefficients of high-temperature C5F10O mixed with CO2 and O2 as substitutes for SF6 to reduce global warming potential
复制标题
DOI：
10.1063/1.4993305
复制
发表时间：
2017-07
期刊：
影响因子：
1.6
通讯作者：
L. Zhong;M. Rong;Xiaohua Wang;Junhui Wu;Guiquan Han;G. Han;Yanhui Lu;A. Yang;Yi Wu
中科院分区：
文献类型：
--
作者：
L. Zhong;M. Rong;Xiaohua Wang;Junhui Wu;Guiquan Han;G. Han;Yanhui Lu;A. Yang;Yi Wu
最近发现 C5F10O 是 SF6 非常有前途的替代品。本文致力于研究高温C5F10O与CO2和O2混合的组成、热力学性质和输运系数。首先，基于G4(MP2)理论计算了混合物中可能存在的几种分子(CxFy和CxFyO)的配分函数和生成焓。上述分子的异构体是根据它们的吉布斯能量来选择的。然后使用吉布斯自由能的最小化确定 C5F10O-CO2-O2 混合物的组成。接下来，从先前计算的成分中得出热力学性质（质量密度、比焓和比热）。最后，基于 Chapman-Enskog 方法计算传输系数（电导率、粘度和热导率）。研究发现，C5F10O作为灭弧气体，灭弧后温度降至室温时，不能再复合。此外，如果不考虑石墨，室温下的关键物质始终是CF4、CO2和C4F6。考虑到这一点，石墨将取代 C4F6 成为主要颗粒之一。 CO2 与 C5F10O 等离子体的混合会显着影响热力学性质（例如，比热峰的消失和/或移动）和传输系数（例如，降低粘度和改变热导率峰的数量），而在 C5F10O-CO2 混合物中添加 O2 对热力学和传输性质没有显着影响。
C5F10O has recently been found to be a very promising alternative to SF6. This paper is devoted to the investigation of compositions, thermodynamic properties, and transport coefficients of high-temperature C5F10O mixed with CO2 and O2. Firstly, the partition functions and enthalpies of formation for a few molecules (CxFy and CxFyO) which are likely to exist in the mixtures, are calculated based on the G4(MP2) theory. The isomers of the above molecules are selected according to their Gibbs energy. The compositions of C5F10O-CO2-O2 mixtures are then determined using the minimization of the Gibbs free energy. Next, the thermodynamic properties (mass density, specific enthalpy, and specific heat) are derived from the previously calculated compositions. Lastly, the transport coefficients (electrical conductivity, viscosity, and thermal conductivity) are calculated based on Chapman-Enskog method. It is found that, as an arc quenching gas, C5F10O could not recombine into itself with the temperature decreasing down to room temperature after the arc extinction. Besides, the key species at room temperature are always CF4, CO2, and C4F6 if graphite is not considered. When taken into account, graphite will replace C4F6 as one of the dominate particles. The mixing of CO2 with C5F10O plasma significantly affects the thermodynamic properties (e.g. vanishing and/or shifting of the peaks in specific heat) and transport coefficients (e.g. reducing viscosity and changing the number of peaks in thermal conductivity), while the addition of O2 with C5F10O-CO2 mixtures has no remarkable influence on both thermodynamic and transport properties.