大气环境下输电线路导线腐蚀与防护的研究

发布时间：2019-06-10 18:32

【摘要】：输电线路是电网运行的基础，架空导线是输电线路的主体材料。钢芯铝绞线作为现行服役时间最长，应用范围最广的导线，其应用的主体地位在未来相当长的一段时间不会改变。钢芯铝绞线的安全可靠运行对保障电力输送至关重要。然而钢芯铝绞线服役环境较为复杂，在大气环境中易受到各种腐蚀因素的影响从而引发导线的腐蚀断裂。本文选用输电线路常用的LGJ240/30型钢芯铝绞线为研究对象，采用Tafel直线外推法，失质法，周期性干/湿循环盐雾模拟海滨环境进行加速腐蚀，研究钢芯铝绞线在50g/L NaCl溶液中的腐蚀行为。实验结果表明，在中性NaCl条件下，随着NaCl浓度由20g/L增高到100g/L时，铝线的自腐蚀电位（开路电压）发生负向偏移，铝线的腐蚀速度变快；盐雾实验结果表明，在腐蚀初期，大量Cl-破坏了铝线表面的Al2O3钝化膜，使铝线裸露出铝基体，在潮湿环境下与钢芯镀锌层形成原电池，加速镀锌层的腐蚀，待锌层消耗完毕后，铝与钢芯形成原电池，铝的腐蚀速度又变快，，但随着腐蚀产物的增多，铝线的腐蚀速度逐渐变小。对在服役过程中发生断裂的钢芯铝绞线进行分析，发现导线在断裂前受到了严重的腐蚀，对导线表面附着的污浊物进行分析，发现其成分较为复杂，为油脂、大气浮尘、酸腐蚀产物等组成的混合物。主要成分为CaSO42H2O、CaSO4、CaCO3、SiO2和CaCl2，分析认为恶劣大气环境下的Cl-和SO2是造成钢芯铝绞线腐蚀的主要原因。
[Abstract]:The transmission line is the foundation of the grid operation, and the overhead conductor is the main material of the power transmission line. The steel-cored aluminum stranded wire has the longest service time and the most widely used lead, and the main body position of the steel core is not changed for a long time in the future. The safe and reliable operation of the steel core aluminum strand is of great importance to the guarantee of power delivery. However, the service environment of the steel-cored aluminum strand is more complex, which is susceptible to various corrosion factors in the atmospheric environment, thus leading to the corrosion and fracture of the lead. In this paper, the LGJ240/30 steel-core aluminum strand used in the power transmission line is selected as the research object, and the corrosion of the steel-cored aluminum strand in 50 g/ L NaCl solution is studied by adopting the Tafel straight-line extrapolation method, the loss-of-mass method, the periodic dry/ wet-circulation salt spray simulation and the coastal environment. The results show that, under the condition of neutral NaCl, with the concentration of NaCl increased from 20 g/ L to 100 g/ L, the self-corrosion potential (open circuit voltage) of the aluminum wire is negatively offset, and the corrosion rate of the aluminum wire is fast; and the salt spray test results show that in the beginning of the corrosion During the period, a large amount of Cl-damaged the Al2O3 passivation film on the surface of the aluminum wire, so that the aluminum wire is exposed out of the aluminum base body, a primary battery is formed in the wet environment and the steel core zinc-plating layer, the corrosion of the galvanized layer is accelerated, and after the zinc layer is consumed, the aluminum and the steel core form a primary battery, and the corrosion speed of the aluminum is changed Fast, but with the increase of the corrosion products, the corrosion rate of the aluminum wire is gradually changed. It was found that the lead was seriously corroded in the course of service, and it was found that the lead was seriously corroded before the fracture, and the dirty object attached to the surface of the wire was analyzed, and the composition was found to be more complex, and it was composed of grease, air floating dust, acid corrosion products and the like. The main components of the mixture are CaSO42H2O, CaSO4, CaCO3, SiO2 and CaCl2.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM75

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