The role of high purity sulfur hexafluoride
High purity sulfur hexafluoride is also widely used in metal smelting, aerospace, medical (X-ray machines, laser machines), meteorology (tracer analysis), chemical (new fire extinguishers) and so on. It has good electrical insulation function and excellent arc extinguishing function.
High purity sulfur hexafluoride is mostly used in high and high voltage power equipment. With the development of science and technology, sf6 has been expanding in the field, and is more and more widely used in the basic and scientific fields.
In high temperature arc, the differentiation and ionization of high purity sulfur hexafluoride will occur, which, along with the energy consumption, has a great influence on the thermal conduction process. Therefore, the thermal conductivity at this time can be considered to be composed of two parts, namely the standard thermal conductivity and the weight related to the differentiation and ionization reactions.
However, as far as gas medium is concerned, the heat transfer ability of high purity sulfur hexafluoride is not merely conduction, but largely depends on convective heat transfer. Convective heat transfer is due to the existence of part of the pressure difference, so that the gas medium produces macroscopic movement to disperse the heat. The convective heat transfer ability of gas medium is related to the specific heat capacity and viscosity of gas.
Secondly, the diameter of sulfur hexafluoride molecule is larger than that of oxygen and nitrogen molecules in the air, which greatly shortens the uniform free travel of free electrons in sulfur hexafluoride gas and makes it difficult to accumulate energy in the electric field, thus reducing the ability of free electrons to collide and dissociate.