1. How to protect the human body from lightning?
Answer: When a person is struck by lightning, the current quickly passes through the human body, which can cause paralysis of the respiratory center, cardiac arrest, and cause burns of varying degrees. In severe cases, brain tissue can be hypoxic and die.
In the thunder-prone summer, people should pay great attention to lightning protection. When lightning occurs, try to avoid using home appliances, such as radios, televisions, computers, telephones, etc., and ground the outdoor antennas and power cords well, and stop using air conditioners, refrigerators, and range hoods to prevent induction Violations of thunder and lightning waves. The doors and windows of the house should be closed well. For families with conditions, the doors and windows can be installed with metal mesh cover and well grounded to prevent spherical lightning from entering the room. If people are outdoors, they should enter places with lightning protection facilities in time during thunderstorms, and do not take shelter under isolated poles, eaves, big trees, and chimneys. When the lightning distance is very close, do not open an umbrella with iron poles, avoid metal objects above your head, and do not use mobile phones to avoid direct lightning strikes. When working in a paddy field or swimming in a river, you should leave the water immediately to prevent lightning from being struck by the conduction of water. During a thunderstorm, if you feel numbness in your head, neck, or body, this is a sign of an imminent lightning strike and you should lie down immediately. In case of encountering a person stunned by lightning, artificial respiration and external heart squeeze massage should be performed immediately, and they should be sent to the hospital for rescue in time.
2. How to protect buildings (structures) from lightning?
Answer: The increasing number of tall buildings (structures) in cities has led to aggravation of lightning accidents; modern electronic equipment with weak anti-interference capabilities such as communications and computer networks within buildings (structures) are becoming more popular; many tall buildings (Structures) The imperfect protective facilities of structures make their lightning protection capabilities congenital inadequate; a large number of communications, computer network systems, etc. are not designed and installed in strict accordance with the national technical specifications before they are put into use. These have become important for the frequent occurrence of lightning disasters. the reason.
Preventing lightning disasters is important. Cold-shrinkable cable terminal tall buildings (structures) shall be installed with lightning protection facilities in accordance with the requirements of the specification, and the design review, construction supervision, and completion acceptance of the buildings (structures) lightning protection facilities shall be strictly carried out. Carry out a wide range of lightning protection knowledge propaganda, especially for those owners of tall buildings (structures), to investigate one by one, and promptly take measures when problems are found, and rectify within a time limit. Units that do not have qualifications or certificates for the design and construction of lightning protection facilities must be resolutely banned to prevent problems before they occur.
In addition, the necessary items should be assessed for the risk of lightning disasters.
3. How to protect against lightning in flammable and explosive places?
Answer: Gas stations, liquefied gas stations, natural gas stations, oil pipelines, oil storage tanks (pools), oil wells, ammunition depots and other flammable and explosive places, if the necessary lightning protection facilities are lacking, it will cause major lightning disasters. loss. In addition to the installation of anti-lightning facilities in such places, gas (oil) tanks (pools) and pipelines, equipment, etc. must also be installed with anti-static induction lightning and anti-electromagnetic induction lightning devices. Special personnel should be designated to take care of them and deal with problems in time. And regularly apply for testing to professional testing institutions.
4. How to protect the computer and its venue from lightning?
Answer: In order to prevent the computer and its local area network or wide area network from being struck by lightning, many units simply install lightning arresters on the modem connected to the external line. However, due to electrostatic induction lightning and anti-electromagnetic induction lightning, the equipment is mainly destroyed through the power supply line. Therefore, the lightning protection of the computer information system is first to install a power surge arrester reasonably, and then to install a signal line and an antenna feeder lightning arrester. If the equipment configuration of the building information system includes a computer center room, a program-controlled switch room, and a machine room for confidential equipment, then a power surge arrester should be installed at the main power source. According to the requirements of relevant standards, lightning arresters must be installed in Zone 0, Zone 1, and Zone 2 respectively (Zone 0, Zone 1, and Zone 2 are divided according to the intensity of lightning occurrence). A series power arrester (multi-stage integrated type) should be installed at the front end of each device to minimize the energy induced by lightning. At the same time, the MODEM, routers, and even HUBs in the computer center all have lines out of the house. These lines out of the house should be regarded as lightning introduction channels, and signal lightning arresters should be installed. While protecting the electronic equipment such as computers in the building, it is safer to install lightning protection facilities on the buildings (structures).
5. Lightning protection for high-voltage equipment
Answer: High-voltage equipment such as power stations, high-voltage substations, and high-voltage transmission lines in the power system are extremely prone to generate ultra-high voltage when lightning occurs, causing equipment damage. Usually in engineering, one or more levels of fortification are often adopted according to the importance of the equipment and the ability to withstand high voltages. The amplitude of high-voltage lightning pulses is reduced by adopting methods such as the grounding of the power transmission grid fittings, the parallel capacitor or transformer isolation between the phase line and the ground line, so that the equipment is protected.
6. How does the lightning rod protect against lightning?
Answer: Lightning rods are used as lightning protection for air-termination. The lightning rod is connected to the underground through a wire, forming an equipotential difference with the ground. Using its own height, the electric field of the lightning cloud with the electric field strength increased to the limit value will be distorted, and the lightning rod will begin to ionize and lead downward discharge; the lightning rod will produce a sharp discharge under the action of a strong electric field; An upward pilot discharge is formed; the two will converge to form a lightning path, which then flows into the earth to achieve the lightning protection effect.
In fact, the lightning arrester is a lightning rod, which can attract the surrounding lightning and discharge it in advance, and transmit the lightning current to the ground through its own grounding conductor to prevent the protected object from being directly struck by lightning. The installed lightning rods and wires must have good electrical conductivity, and the grounding network must ensure the smallest possible impedance value. According to the different lightning protection lines of the protection objects, it can be divided into single lightning protection line, double lightning protection line or multiple lightning protection lines. Lightning lines with different cross-sectional areas can be specifically determined according to the shape and volume of the protected object. The lightning protection wires of lightning arrester manufacturers generally use galvanized steel strands with a cross-sectional area of not less than 35 square millimeters. Its protective effect is equivalent to that every point on the sag is a lightning rod of equal height.
