接地用铜覆钢铜层厚度计算方法及分析

Calculation Method and Analysis of Copper Layer Thickness of Copper-clad Steel for Grounding

铜覆钢接地装置的选型设计包括铜覆钢截面和铜层厚度,其中铜层厚度的确定是重中之重。基于接地装置全寿命周期的要求,提出了铜覆钢铜层厚度的计算方法。该方法考虑了铜覆钢作为接地体(或接地线)时铜层应有的导电要求和抗腐蚀要求,即在接地装置设计寿命内铜覆钢应满足热稳定校验时的导电率限值,具体是通过热稳定校验确定的导电率可计算出导电要求的铜层厚度,通过土壤对铜的腐蚀速率可计算出抗腐蚀要求的铜层厚度,两者之和即为铜覆钢的铜层最小厚度。铜层厚度的计算示例表明,在铜覆钢选型设计时,C值选取不大于150是具有经济性的。

The type selection design of copper-clad steel grounding device includes copper-clad steel section and copper layer thickness,among which the determination of copper layer thickness is the most important.Based on the requirement of the life cycle of grounding device,a calculation method of copper layer thickness of copper-clad steel is proposed in this paper.This method takes into account the requirements of conductivity and corrosion resistance of copper layer when copper-clad steel is used as grounding electrode(or grounding conductor),that is,the copper-clad steel should meet the conductivity limit of thermal stability checking during the design life of grounding device.Specifically,The thickness of copper layer required for conductivity can be calculated through the conductivity determined by thermal stability verification,and the thickness of copper layer required for corrosion resistance can be calculated through the corrosion rate of soil to copper.The sum of the two is the minimum thickness of copper layer of copper-clad steel.The calculation example of copper layer thickness shows that it is economical to select C value less than 150 in the type selection and design of copper-clad steel.