www.2cas.cn-青苹果乐园,国产精品国产三级国产专不?,久久人妻夜夜做天天爽,中文字幕欧美中日韩精品

      • <strike id="amgce"></strike>
      • <ul id="amgce"><sup id="amgce"></sup></ul>
        <strike id="amgce"><input id="amgce"></input></strike>
        <strike id="amgce"><menu id="amgce"></menu></strike>

          Contact UsMore>>

          Jiangsu Tianli Steel Structure Co., Ltd.

          General Manager: Mr. Zhu Hongjun

          Phone: 0511-88135999

          Contact: Mr. Chen Helin

          Phone: 0511-88131777

          Mobile: 13952238816

          Fax: 0511-88131118


          News

          How to calculate the protection range of lightning tower

          Author:admin Time:2018-11-12 10:42:00
          What kinds of calculation methods are there for the protection range of lightning arresters? This paper summarizes the calculation methods commonly used in the protection range of lightning arresters in the Electrician's Home. I hope it will be helpful to all of you.
          At present, the formulas for calculating the protection range of lightning rods in different countries in the world are different in form. Generally, there are several methods for calculating the protection range of lightning rods as follows:
          1. Broken line method: that is, the protection range of a single lightning rod is a broken line cone.
          2. Curve method: that is, the protection range of a single lightning rod is a curve cone.
          3. Straight-line method: the point of lightning rod is used as the vertex to make a depression angle to determine, the building with explosion danger is used 45 degree angle, and the general building is used 60 degree angle, essentially the protection range is straight cone.
          Since 1983, China has formally formulated its own lightning protection standards. At present, China's building lightning protection code GB50057-94 also adopts the rolling ball method recommended by the International Electrotechnical Commission (IEC) as the calculation method of lightning rod protection range.
          According to the calculation method of lightning rod protection range, the commonly used calculation methods of lightning rod protection range mainly include folding line method and rolling ball method. Therefore, the calculation of "folding line method" and "rolling ball method" are preliminarily analyzed and discussed. It is concluded that the main characteristic of "folding line method" is intuitive design and calculation. It is simple and economical, but the height of buildings over 20m is not applicable. The main feature of "rolling ball method" is that it can calculate the protection range of lightning rod (belt) and grid combination, but the calculation is relatively complex and the investment cost is relatively large.
          国产猛男猛女超爽免费视频| 国产高潮视频在线观看| 国产高清在线精品一区二区三区| 亚洲AV无码片一区二区三区| 亚洲日韩精品A∨片无码不卡| 99精品国产福利一区二区| 国产成人欧美精品视频APP| 97国产精华最好| 中文字幕乱码人妻一区二区三区| Av网址免费观看网站|