Study of Arc by-Products in Gas-Insulated Equipment. Final Report

摘要

The project objective was to develop a chemical data base for sulfur hexafluoride, SF sub 6 decomposition products as generated by electrical discharges within gas-insulated equipment to serve as a basis for unified handling procedures of faulted SF sub 6 equipment and disposal of the arc products. An analysis capability was to be developed that could be used by utilities for incipient and actual fault analysis on SF sub 6 insulated power equipment. Arced SF sub 6 gas and solid samples were generated in test devices which simulate SF sub 6 circuit breakers or SF sub 6 insulated bus. Actual production hardware and procedures were used for assembly of the test devices. Fault arc currents ranged between 15 kA and 50 kA. Arced SF sub 6 samples were obtained and shipped in stainless steel cylinders. Gaseous arc products were analyzed with a combination of gas chromatography-mass spectrometry. The attained sensitivity is 100 ppM. The major SF sub 6 arc products are SOF sub 2 and CF sub 4 . The amount increases with the arc energy. SOF sub 2 can effectively be removed by absorber-scrubbers containing soda-lime, activated alumina and molecular sieves. The solid arc products consisted of metal fluorides (AlF sub 3 and CuF sub 2 .2 H sub 2 O). Airborne dust, collected upon opening of the faulted test section had a size of about 10 micron. (ERA citation 06:010877)