| In today’s power system construction, Gas Insulated Switchgear (hereinafterreferred to as GIS) has been widely used used in substations. The insulating mediumused in the GIS is sulfur hexafluoride (SF6) gas, which has stable chemical propertiesand excellent insulation and arc extinction performance. Internal defect of GIS wouldinevitably cause some part electric fields become too strong, and lead partial discharge(partial discharge, PD) occuring. Energy generated by discharge causes SF6gasdecomposes and generates a variety of low fluoride sulfides. Especially when mixedwith a small amount of water or oxygen in GIS, these low fluoride sulfides furtherwould irreversible generate SOF2, SO2F2and SO2and other characteristics of thecomponent gases. Finally it causes problem for GIS normal operation. Currently,typically by gas chromatography and other methods to detect the content of thesefeatures components gas to judge the inside insulation fault of GIS. However, theexisting detection methods are mostly done off-line in the laboratory, which can not beachieved on line. So this paper bases on that the nanotube sensing technology detectsthe characteristics components gas of SF6, developed precious metal-doped TiO2nanotube gas sensor. Study the impact on the precious metal-doped TiO2nanotubemicro-sensing mechanism and macro-gas sensing characteristics through a series ofexperiments to.This paper used the anodic oxidation method prepare the TiO2nanotubes gassensor, And on this basis, Pt and Au nanoparticles deposited on the TiO2nanotubesusing the pulse electrochemical deposition method. So the different amouts Pt and Audoped TiO2nanotubes sensor was prepared. Through the SEM, XRD observation, theTiO2nanotubes array is anatase mainly, and doped noble metal particles dispersed onsurface of the nanotubes uniform.Improved the own design platform which is used to test the gas sensingperformance of TiO2nanotubes sensor, studied the gas response characteristics andtemperature characteristic of the different amount Pt doped TiO2nanotubes sensor toSF6gas decomposition compositions SO2, SOF2and SO2F2.The result is that: the bestwork temperature and gas sensing characteristics of the different Pt doped sensor isrelated to doping the size. Among them, optimum operating temperature of the doping10s time is160℃,20s is150℃,30s is130℃, and40s is100℃. As the doping amount increases, the optimum point of the operating temperature of the sensor drops. Theselectivity of the sensor is also much concerned with the amount of doping,10s mostsensitive to SO2, which is-53.25%， and30s is most sensitive to SO2F2, which is-50.58%. Through the UV irradiates light TiO2nanotubes can prolong the life and hasgood recovery characteristics.In the same condition, we also tested the gas response characteristics andtemperature characteristic of the Au doped TiO2nanotubes to SO2, SOF2and SO2F2. Thebest working temperature of Au doped TiO2nanotubes sensor is110°C, and thesensitivity response of the Au doped TiO2nanotubes sensor to100ppm SO2F2is up to-42.31%, and to SOF2, SO2are-28.37%and-23.75%It is means that the sensor hasbetter selectivity to SO2F2gas. and the Pt nanoparticles doping changes gas selectivityof TiO2nanotubes sensor to SO2, SOF2and SO2F2and reduces the sensor’s workingtemperature. We preliminary discussed the reason for the gas sensitive changes of theTiO2nanotubes sensor when doped Pt nanoparticles.Compared with the intrinsic sensor,Au nanoparticles doped significantly changed the selectively of sensor to SO2, SOF2andSO2F2and significantly reduces the operating temperature of the sensor. Compared withthe Pt-doped sensor, which is less likely poisoning by sulfur. |
PDF Full Text Request