Classification and measures of lightning protectio

Classification and measures for lightning protection of buildings

Abstract: buildings should be divided into three categories according to lightning protection requirements according to their importance, nature of use, possibility and consequences of lightning accidents

key words: classification of lightning protection of buildings lightning protection measures Untitled Document 1 1 Classification of lightning protection for buildings buildings shall be divided into three categories according to their importance, nature of use, possibility and consequences of lightning accidents. 1. It should be classified as the first type of Lightning Protection Buildings: first, all buildings that manufacture, use or store explosives, gunpowder, primary explosives, initiating explosive devices and other large quantities of explosive substances will explode due to electric sparks, which will cause great damage and casualties. 2、 Buildings with explosion hazard environment in Zone 0 or zone 10. 3、 Buildings with explosion hazardous environment in zone 1 will explode due to electric sparks, which will cause huge slope damage and personal casualties. 2. It should be classified as the second type of Lightning Protection Buildings: first, buildings under national key cultural relics protection. 2、 National halls, office buildings, large exhibition and Expo buildings, large railway stations, state guesthouses, national archives, important water supply pump rooms in large cities and other particularly important buildings. 3、 National computing centers, international communication hubs and other buildings with a large number of electronic equipment that are of great significance to the national economy. 4、 Buildings that manufacture, use or store explosive substances, and electric sparks are not easy to cause explosion or cause great damage and personal casualties. 5、 Buildings with explosion hazardous environment in zone 1, and electric sparks are not easy to cause explosion or cause great damage and casualties. 6、 Buildings with explosion hazard environment in zone 2 or 11. 7、 Open air Steel closed gas tanks with explosion risk in industrial enterprises. 8、 Ministry and provincial office buildings and other important or densely populated public buildings with an estimated number of lightning strikes greater than 0.06/a. 9、 Residential buildings, office buildings and other general civil buildings with an estimated number of lightning strikes greater than 0.3/a. 3. It should be classified as the third type of Lightning Protection Buildings: first, the buildings and Provincial Archives under provincial key cultural relics protection in order to continue to achieve lightweight and continuously improve power output. 2、 Ministry and provincial office buildings and important or densely populated public buildings with an estimated number of lightning strikes greater than or equal to 0.012/a and less than or equal to 0.06/a. 3、 Residential buildings, office buildings and other general civil buildings with an estimated number of lightning strikes greater than or equal to 0.06/a and less than or equal to 0.3/a. 4、 General industrial buildings with an estimated number of lightning strikes greater than or equal to 0.06 times/a. 5、 According to the impact of lightning on industrial production and its consequences, and in combination with local meteorological, topographic, geological and surrounding environment factors, determine the fire hazard environment in zone 21, 22 and 23 that need lightning protection. 6、 In areas where the average Thunderstorm Day is greater than 15d/a, isolated tall buildings such as chimneys and water towers with a height of 15m or more; In areas where the average Thunderstorm Day is less than or equal to 15d/a, there are isolated tall buildings such as chimneys and water towers with a height of 20m or more. Note: 1 In the case that buildings equipped with information systems need to be protected against lightning, and the coating free team adopts the effect powder with special structure and the magnetic pulse of the unique powder surface treatment process, when the building is not protected against direct lightning and is not within the protection range of other buildings or objects, the lightning protection measures against direct lightning should be taken according to the third type of lightning protection buildings. Under the condition of considering shielding, lightning arrester against direct lightning should be used. 2. Lightning protection measures should be taken for buildings in areas with frequent lightning disasters in history. １. 2 lightning protection measures for buildings 1 2.1 general regulations 1 All kinds of lightning protection buildings should take measures to prevent direct lightning and lightning wave intrusion. The first type of lightning protection raises the lifting arm by 1 lifting angle α Lightning induction prevention measures shall also be taken for buildings and class II lightning protection buildings specified in paragraphs 4, 5 and 6. 2. Buildings equipped with lightning protection devices should adopt equipotential connection when the lightning protection devices cannot be isolated from other facilities and personnel in the buildings. １. 2.2 lightning protection measures for class I lightning protection buildings independent lightning rod () 1 The measures to prevent direct lightning strike should meet the following requirements: first, independent lightning rods or overhead lightning wires () should be installed so that the protected buildings and objects protruding from the roof, such as hoods and vent pipes, are within the protection range of lightning arresters. The grid size of overhead lightning protection shall not be greater than 5m × 5m or 6M × 4m。 2、 The following spaces outside the orifices of vent pipes, breathing valves, exhaust pipes, etc. discharging explosive dangerous gases, vapors or dust shall be within the protection range of the lightning arrester: when there is a pipe cap, it shall be determined according to Table 1-1; When there is no pipe cap, it should be a hemisphere with a radius of 5m above the nozzle. The contact data between the lightning arrester and the lightning flash must be provided with a nameplate, and the point should be set outside the above space. Table 1-1 pressure difference (kPa) between the pressure in the space device outside the nozzle with a pipe cap and within the protection range of the air termination the specific gravity of the discharge the vertical height above the pipe cap (m) the horizontal distance from the nozzle (m) <5 is heavier than air 125 ~ 25 is heavier than air 2.5 5 ≤ 25 is lighter than air 2.5 5> 25 is heavier than air 55 III. The dispersion pipe, breathing valve For exhaust pipes, etc., when their emissions do not reach the explosion concentration, long-term ignition and combustion, ignition and combustion as soon as they are discharged, and for ventilation pipes and safety valves whose emissions reach the explosion concentration only in the event of an accident, the protection range of the lightning arrester can only be protected to the pipe cap, and when there is no pipe cap, it can only be protected to the pipe orifice. 4、 The pole and tower of independent lightning rod, the end of overhead lightning wire and