【作者】 赵鹏；

【导师】 雷阿利； 闫爱军；

【作者基本信息】 西安理工大学 ， 材料科学与工程， 2010， 硕士

【摘要】 接地网是保障变电站安全运行的重要设备,随着超高压输变电的发展,接地网的防腐蚀成为电力安全运行的关键。为此,陕西省电力公司下达了《变电站接地网防腐蚀技术研究与应用》的研究项目,本论文根据项目的要求,采用土壤缓蚀剂与外加电流阴极保护相结合的方法对接地网进行防护研究,实验室的研究结果在渭南孝义750kV变电站进行埋设工程试验。在缓蚀剂研究时,通过对比法对缓蚀剂的用量、温度、土壤的含水量等研究,筛选出用量小、保护效果好的缓蚀剂配方；外加电流阴极保护的研究,采用电化学三电极系统测试了土壤环境中碳钢试样的极化曲线,获得了最佳的保护电压等保护参数,在此基础上计算了保护度；研究了接地网腐蚀速度与电阻之间的关系,为工程中电阻法测量接地网的腐蚀速度提供基础。试验得出以下结论：(1)对Q235钢接地网在土壤中缓蚀效果最好的复配缓蚀剂为0.4%亚硝酸钠、1.2%六偏磷酸钠和1.6%钼酸钠,保护度可达91.8%。(2)外加电流法阴极保护能够起到较好的保护效果,当外加电压为-1.5V(SCE)时,平均保护度为78.3%,当缓蚀剂和外加电流阴极保护联合保护时,保护度可达96%以上。(3)在膨润土中进行添加缓蚀剂和外加电流阴极保护,保护度可达98%,但保护效果受膨润土含水量影响较大。(4)接地网工程埋片试验发现杂散电流对变电站接地网腐蚀有较大影响。复配缓蚀剂与外加电流法阴极保护共同作用保护度仅为89.6%,比实验室研究的保护度降低了近10%。(5)接地网点腐蚀试验中,腐蚀深度△与电阻R的关系为最小横截面积对电阻值影响最大。更多还原

【Abstract】 Grounding grid is an important device which ensure the safe operation of Substation. With the development of High Voltage Transmission, grounding grid corrosion is the key to the safe operation of the electric power. For this reason, Shanxi Provincial Power Company issued a research project as "Substation Grounding Grid Corrosion Protection". According to the requirements of the project,the protection of grounding grid was studied,using of soil inhibitor with impressed current cathodic protection method of combining. Meanwhile, Laboratory test results were laid in Weinan Xiaoyi 750kV Substation as Engineering Test. In the inhibitor study, by antithesis corrosion inhibitor concentration, temperature, soil moisture, etc were studied, selected the corrosion inhibitor formulations in low concentration with good effects. In the Impressed Current Cathodic Protection study, the polarization curves of carbon steel test samples in soil environment was detected by electrochemical three-electrode system, parameters such as the protection voltage were determined, on this basis, the degree of protection was calculated. Grounding Grid Corrosion relationship between speed and resistance was studied, which provided the basis for resistance method for corrosion rate measurement of grounding grids in project. The main conclusions are as follows:(1) Corrosion inhibitor formulation which have the best prevention of Q235 steel grounding grid corrosion effect in the soil as follows:0.4% NaNO2,1.2%(NaPO3)6 and 1.6% Na2MoO4, protection degree of up to 91.8%.(2) Impressed Current Cathodic Protection Act have better protection, When the protective voltage is-1.5V(SCE), the average protection degree is 78.3%. Corrosion inhibitor and impressed current cathodic protection act joint protection, protection degree of up to 98%.(3) Corrosion inhibitor and impressed current cathodic protection in bentonite, the protection degree of up to 98%, but the protective effect influenced by the moisture content in bentonite. (4) It was found that stray electrical currents have a significant impact on substation grounding grid corrosion in grounding grid burial sample experiment. Mixed inhibitor with impressed current cathodic protection combined action protection degree is only 89.6%, Compared with the results of laboratory studies to reduce by nearly 10%.(5) In the grounding grid pitting corrosion experiments, Corrosion depth A relationship with the resistance R is Minimum cross-sectional area has the greatest impact on resistance.更多还原