Calculation of the adsorption properties of ZrB and HfB on the main decomposition products of environmentally friendly insulating gases based on the first-principle

Abstract

In recent years, fluorocarbon gases C4F7N and C5F10O, as potential alternative gases to SF6, have gained widespread attention due to their good insulation performance and environmental friendliness. However, as partial discharges inevitably occur within the equipment during actual operation, this causes partial decomposition of the fluorocarbon gas, which can result in the failure of electrical equipment and even threaten the stable operation of the power system. It is therefore important to monitor their decomposition, of which CF4, C3F6 and COF2 are the three main decomposition products. In this paper, the adsorption energy, charge transfer amount and the density of states of these three typical gas molecules were calculated and compared based on the First-principle, using ZrB and HfB as adsorbent materials. The results show that the adsorption strength of both ZrB and HfB is CO2F > C3F6 > CF4, and that all gas molecules gain electrons from the material surface during the adsorption process. Considering the adsorption energy and recovery time, it is concluded that ZrB can be used as an adsorbent for COF2, while HfB has the potential to be used as an adsorbent for COF2 or a C3F6 gas-sensitive material for online detection of gas-insulated equipment in power systems.

Keywords

• First-principle
• ZrB
• HfB
• Adsorption characteristics
• Recovery time