Heptafluoroisobutyronitrile (C4F7N) has excellent insulation properties and low greenhouse effect, and is currently the mainstream environment-friendly gas used for electrical equipment insulation. Because of the large differences in physical and chemical properties between C4F7N and SF6, the current SF6 detection technology and equipment can not meet the application requirements of C4F7N gas mixture. In this paper, the detection method of C4F7N/CO2 gas mixture was studied by referring to the live detection technology of SF6 gas in operating equipment. The field detection schemes were proposed, which included using gas chromatography to detect purity and composition of gas based on high-precision helium ionization detector, using thermal conductivity principle to detect C4F7N ratio, using resistance capacitance sensor method to monitor micro-water content, and using non-spectral infrared technology combined with Lambert-Bill rule to quantitatively monitor gas leakage fault, and the corresponding detection devices were developed to carry out the detection and verification test for gas state. The results show that all detection schemes have high detection accuracy and can support the operation and maintenance testing and field application of C4F7N environment-friendly electrical equipment.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |