用滚球法确定避雷针保护范围的几个问题商榷

Discussion on Several Problems of Determining the Protection Range of Lightning Rod by Rolling Ball Method

针对滚球法仅用半径为h_(r)的圆弧确定高度为h的避雷针的保护范围,存在单支h的保护范围横向偏宽纵向偏窄、保护范围不确定性、仅适用于h≤h_(r)、采用大小不等的h_(r)确定两支h之间的保护范围等问题,文章根据滚球的雷击能力及h的保护能力,分析滚球法的单支h及两支h的保护范围所存在的问题,提出用h_(r)与h的保护能力共同确定保护范围的改进方法。结果表明,滚球法的单支h的保护范围横向偏宽超出了h的保护能力,纵向偏窄压小了保护范围;采用大的h_(r)确定的两支h之间的保护范围偏宽,而采用小的h_(r)则压低了被保护物的高度,不合理。改进后,上述问题得到了解决,滚球法可适用于任意高度的h,单支h及两支h之间的保护范围均在h的保护能力之内,保护范围合理。

In view of the problems of using only h_(r) to determine the protection range of h in the rolling ball method,such as the protection range of single branch h is wide in transverse and narrow in longitudinal,protection range is uncertain,only applicable to h≤h_(r),and using h_(r) of different sizes to determine the protection range between two branches h,according to the lightning strike ability of the rolling ball and the protection ability of h,the problems existing in the protection range of single branch h and two branches h of the rolling ball method are analyzed,and the improvement of using the h_(r) and the protection ability of h to jointly determine the protection range is put forward for discussion.The analysis shows that the transverse part of the protection range of single branch h by rolling ball method exceeds the protection ability of h,and there are lightning protection loopholes.The longitudinal narrow part reduces the protection range;The protection range between the two branches h determined by large h_(r) is too wide,and the use of small h_(r) will lower the height of the protected object,which is unreasonable.The improved rolling ball method can be applied to any height of h,and the protection range between single branch h and two branches h is within the protection ability of h,and the protection range is reasonable.