1.The generation of lightning Lightning is an atmospheric photoelectric phenomenon produced in strong convective weather. The strong lightning flash accompanying the discharge of different electric charges in the cloud, between clouds or between clouds and ground attracts each other and is called lightning, and the sound of the rapidly expanding gas along the lightning channel is what people call thunder. According to the charge properties of like-sex repulsion and opposite-sex attraction, when the electric field strength between cloud blocks with opposite-sex charges or between cloud blocks and the earth increases to a certain level (about 25-30 kV/cm), it will break down the air and generate a strong arc light Discharge, this is what we usually call lightning. At the same time, the air in the discharge channel is heated to a high temperature (up to 20,000 degrees) and rapidly expands due to the thermal effect generated by the strong current, making a strong explosion sound, which is thunder. Lightning and thunder are called lightning phenomena. 2. Classification and destructive effect of lightning Lightning is divided into direct lightning, induction lightning and spherical lightning. For a long time, thunder and lightning have brought catastrophic blows to human beings, creatures on earth and human civilization in the form of direct lightning strikes. Disasters such as casualties and destruction of buildings are often caused. 3, lightning protection principle In thunderstorm weather, we sometimes see some towering trees being knocked down by lightning, while some surrounding high-rise buildings such as towers and high-rise buildings are safe and sound. What is the reason for this? These towering trees are also charged with a large amount of electric charge due to the induction of the cloud layer with a large amount of electric charge. When the accumulated electric charge is too much, the tree will be knocked down. Under the same circumstances, the safety of high-rise buildings may be attributed to lightning rods. On many towers, there is something made of metal, shaped like an embroidery needle, and the needle is upright. This is the lightning rod. So, why does this thing that looks like an embroidery needle and is not amazing in appearance have such a great effect and can "avoid lightning"? In fact, the lightning rod should be called "lightning rod". In thunderstorm weather, when charged clouds appear over tall buildings, both the lightning rod and the top of the tall buildings are induced with a large amount of charge, and the air between the lightning rod and the clouds is easily broken down and becomes a conductor. In this way, the charged cloud layer forms a path with the lightning rod, and the lightning rod is grounded. The lightning rod can guide the charge on the cloud to the earth, so that it does not pose a danger to high-rise buildings and ensures its safety. Comprehensive lightning protection is divided into external lightning protection and internal lightning protection. External lightning protection is mainly to prevent direct lightning strikes, and internal lightning protection is mainly to prevent induction lightning.

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Post time: May-07-2022