Emergency plan for lightning protection and lightning disaster in gas station

Emergency plan for lightning protection and lightning disaster in gas station

In normal study, work or life, there is no guarantee that unexpected things will happen. In order to avoid more serious consequences, it is always necessary to make emergency plans in advance. What formats should I pay attention to when writing emergency plans? The following is my carefully prepared emergency plan for lightning protection and lightning disaster in gas stations for reference only. Let's have a look.

Emergency Plan for Lightning Protection of Gas Station 1 1 Direct Lightning Protection

1. 1 Measures against direct lightning in oil storage tank area

The total oil storage capacity of automobile gas stations is mostly around 300m3, and most of them are installed in basements, and the medium is gasoline and diesel. Because gasoline is a flammable liquid, its flash point temperature is low (-50 ~ 30℃) and it is volatile. At room temperature, the oil and gas trapped in the basement and the gas discharged from the breathing valve of the oil storage tank are easy to reach the detonation mixing ratio. Therefore, the oil storage tank area is the key area of lightning protection for gas stations. According to GB50057-94 Code for Lightning Protection Design of Buildings and GB 15599-95 Code for Lightning Protection Safety of Petroleum and Petroleum Facilities, combined with the characteristics of oil storage tanks arranged in the basement. For oil storage tanks, independent lightning rods are used according to the requirements of Class II lightning protection. On the height plane of 2.5m above the breather valve, a protection range with a radius of 5m is set to prevent thunderstorm from directly hitting the breather valve, causing high temperature and igniting oil and gas. In order to prevent the lightning rod from producing high potential counterattack to the oil tank and its ancillary facilities, the lightning rod and its grounding device are adopted.

The distance between the protected oil tank and its related pipelines shall not be less than 3m.

1.2 measures for preventing direct lightning strike in oil kiosk

The oil kiosk is the place where the tanker is installed and refueled. The oil and gas content in the area is high, which belongs to the second-class lightning protection building. It is suggested to lay a lightning protection belt at the top of the exhibition hall, and the lightning protection belt should be long and wide >: when 10m, a lightning protection network of 10m× 10m or 12m×8m should be laid.

2 Anti-induction lightning and anti-static electricity

Oil storage tanks and oil pipelines in gas stations are made of steel. When Lei Yun floats above or near them and is struck by lightning, metal storage tanks and oil pipelines will carry a lot of charges due to electrostatic or electromagnetic induction. In addition, under the conditions of flowing, dumping, shaking, etc., oil generates electrostatic charge due to its own friction or mutual friction with other objects. When the speed of electrostatic charge generated by lightning induction or friction is higher than the discharge speed, electrostatic accumulation of the same charge is formed. When the accumulated electrostatic charge, its discharge energy is greater than the minimum ignition energy of combustible mixture, and the mixture of oil vapor and air is in the explosion limit range in the discharge gap, it will cause explosion and combustion. Therefore, it is stipulated that the oil tanks storing A, B and C oils should be grounded against static electricity to provide discharge channels.

2. 1 Oil tanks and oil pipelines are protected from induced lightning and static electricity.

(1) To ensure reliable grounding, there should be at least two grounding points for each metal oil tank.

(2) The starting point, end point, bend and branch of the oil pipeline should be grounded respectively.

(3) When there are less than five connecting bolts for the pipeline flange, the flange must be bridged with metal wire.

(4) Metal parts on the oil storage tank (breathing valve, flame arrester, oil measuring hole, etc.). ) must have a good equipotential connection with the oil storage tank.

2.2 Anti-induction lightning of power supply and signal line

Most transmission lines in gas stations use overhead lines, which is easy to induce high lightning level. Lightning protection measures are as follows:

(1) Install explosion-proof lightning arrester at the incoming terminal of the power switch in the distribution room; (2) The power cord from the power distribution room to the tank car is buried with steel pipes, and both ends of the steel pipes are respectively connected with the power distribution room and the tank car.

(3) The signal wire connecting the electronic metering tanker with the computer should also be covered with a metal tube. The beginning and end of the metal tube should be connected with the working place, and the interface between the signal wire and the computer should be equipped with a phase arrester.

If the above-mentioned pipeline is erected in the trench, the trench should be filled with sand to prevent the oil and gas trapped in the trench from causing fire when the electrical circuit fails.

2.3 Anti-static of oil unloading vehicle

Unloading oil from tanker is the biggest oil transportation operation in gas station. A large amount of static charge will accumulate on the oil tanker, so it is necessary to set up an anti-static connection device at the oil unloading place to provide a channel for the oil tanker to release static charge.

3 grounding device

(1) The lightning rod adopts independent grounding body, and the grounding impulse resistance is not greater than10Ω.

(2) The grounding body of the oil storage tank is laid in a ring shape around the oil storage tank area, providing a grounding point for the starting point of the oil pipeline and the oil unloading area of the tanker. Grounding impulse resistance is not greater than10Ω.

(3) The oil sales shed adopts a mixed grounding device, which is connected with the grounding body of the building foundation and the artificial grounding body. Among them, the artificial grounding body is laid in a ring around the refueling operation area to reduce the harm of the step voltage in the operation area to the staff. At the same time, the grounding device provides grounding points for electrical equipment such as the end of oil pipeline and tanker, and the impact grounding resistance is determined by the minimum value. Response signal

(4) When the grounding body at the corner and branch of the pipeline is set separately, the impact grounding resistance should not be greater than 30Ω. The grounding body of the oil storage tank area should be equipotentially connected with the grounding body of the oil sales shed.

4 gas station rectification suggestions

In the late 1980s and early 1990s, a large number of gas stations were put into operation. Due to the imperfect management at that time, most of the lightning protection facilities in these gas stations have defects: ① the grounding of oil storage tanks is not standardized, only a little grounding, and some even have no grounding; (2) If there are less than 5 flange connection bolts of the oil pipe, there is no electrical connection; ③ Anti-static grounding device is not installed at the unloading place of the oil tanker. For ② and ③, it is easier to handle. Because the oil tank area can't use arc welding, it is more troublesome to handle. It is suggested that the grounding body be installed outside the basement. After antirust treatment, the rings of the oil tank should be coated with conductive paste, covered with a layer of lead pad, and then the grounding wire should be crimped on the rings with U-bolts. There is only one remedy for this connection, and a comprehensive inspection is made every year before the thunderstorm season. When the transition resistance at the interface is large, it needs to be rusted again.

Emergency Plan for Lightning Protection of Gas Station II During the lightning protection detection and lightning accident investigation, it was found that lightning accidents occurred from time to time in some gas stations due to imperfect lightning protection design and failure to consider the comprehensive lightning protection ability of gas stations. For example, 1998, two tankers in Jiangpu gas station were damaged by lightning, and the distribution cabinet in Shunfeng gas station was damaged by lightning. 1From April to May, 1999, the tanker of Yongxing gas station was damaged by lightning for many times. Gas stations belong to the second type of lightning protection buildings, and their comprehensive lightning protection should be considered from the following aspects:

1 Lightning protection of the building

The buildings of gas stations include fuel sheds, dormitory buildings and other ancillary buildings. In the design and construction of these buildings, the pile of frame structure is used as vertical grounding body, the ground beam and mercury platform are used as horizontal grounding body, the two diagonal main bars in the pile are used as down lead, and the ceiling is used as network (10m× 10m or 8m× 12m). Set lightning protection zone around the sky, and set lightning protection zone around.

2 Lightning protection of oil tank

Metal oil tanks must be grounded annularly, with at least two grounding points, and the arc distance between them should not be more than: 30m, and the distance between grounding body and tank wall should not be less than 3m. Thickness of tank top

3 Lightning protection of power lines and telephone lines

Most lightning accidents in gas stations are caused by the propagation of lightning waves through power lines and telephone lines.

What happened. Protecting power lines and telephone lines is an important part of lightning protection in gas stations.

(1) Lightning protection of power lines

The way to prevent the lightning wave from invading from the power line is to lead the power line into the ground through a metal pipe, and the length of the pipe should not be less than 2ρ(ρ is the local soil resistivity in ω * m). Install a three-phase power arrester at the main power supply of the equipment in the distribution room. Install a special power arrester at the power input end of the equipment. Lightning arresters shall be explosion-proof products.

First, the power level lightning protection

A three-phase switch modular power surge protector is installed behind the main circuit breaker (fuse) and in front of the leakage protector in the 380V low-voltage main distribution box of the gas station, with a flux of 50KA, which is used for the primary power protection of all electrical equipment in the whole gas station.

B, power supply secondary lightning protection

Install a three-phase power surge protector with a flux of 40KA in the distribution box in the office or add a distribution box outside the office for secondary power protection of all IT equipment in the office. A three-phase power surge protector with a flux of 40KA is installed in the power distribution box of the tank car or the additional power distribution box of the tank car, which is used for the secondary power protection of the tank car.

C, power supply level 3 lightning protection

In the office computer management equipment, convenience store charge area tax control host, come on.

Socket-type power surge protector is used for power sockets of machine data transmission equipment, bill printing equipment and other precision equipment.

(2) Protection design of gas station signal system

The communication signal information system surge protector is installed on the tanker control bus of the data collector in each group of tankers, and the communication signal surge protector is installed in the lightning protection and explosion-proof box of the data collector in each group of tankers and the signal circuit of the central control motherboard.

The surge protector of communication signal information system is installed on the data transmission line of the tax-controlled host tanker under the checkout counter of the convenience store for lightning protection of the signal line of the tax-controlled host.

(3) Lightning protection of telephone lines

Most gas stations are built on both sides of roads in open areas, and many telephone lines are introduced overhead. Lightning waves can easily be input through telephone lines, damaging the telephone. Therefore, it is necessary to do a good job in lightning protection of telephone lines. The best way is to bury the telephone line through a metal pipe (the buried length should not be less than 2ρ) before it enters the room, and the metal pipe is connected to the earth pole. And install special telephone lightning protection devices.

In front of MODEN of ADSL network communication line, ISND network communication line and PSTN dial-up network communication line in the office, that is, the incoming end of the network communication line, a network signal information system surge protector is installed to protect the network cards and network communication lines of various devices from lightning.

In the office room, the monitoring equipment cabinet enters the camera field of vision from the refueling platform outside the building.

Surge protector of video information system is installed on frequency transmission line, which is used for lightning protection of signal line of monitoring equipment.

The multifunctional surge protector of the monitoring camera is installed on the power supply and video transmission line of the camera in the outdoor gas filling station for lightning protection of the outdoor monitoring camera.

4 grounding

(1) The lightning protection grounding resistance of the building shall be

(2) The distance between the two grounding devices of the independent lightning rod and the oil tank is Se≥0.4Ri(Ri is impact grounding resistance), but it should not be less than 3m. Grounding resistance is not greater than10Ω.

(3) working grounding, safety protection grounding, lightning arrester grounding and lightning protection grounding of the building should adopt a set of grounding devices, and the grounding resistance should not be greater than 4Ω.

With the rapid economic development in China, the transportation industry is changing with each passing day, people's lives are constantly improving, there are more and more cars, and the number of gas stations is also increasing. Accidents caused by lightning strike occur from time to time every year, which directly threatens the safety of people and buildings around gas stations. Therefore, it is very important to strengthen the lightning protection engineering design of gas stations. However, in those gas stations in suburbs and remote places, the operators' awareness of lightning protection is still very weak, and there is luck and paralysis. Once a lightning accident happens, the consequences are unimaginable. Therefore, the lightning protection measures for gas stations should be designed according to GB50057-20 10 Code for Lightning Protection Design of Buildings, GB50343-2004 Technical Code for Lightning Protection of Building Electronic Information Systems and GB50 156-2002 Code for Design and Construction of Automobile Gas Stations.

Keywords: lightning gas station protection specification

1 overview

Lightning comes from thunderstorms, which are often accompanied by strong convective weather, which is determined by atmospheric circulation and local meteorological factors. Thunderstorm is a discharge phenomenon between clouds or between clouds and the ground in cumulonimbus clouds, accompanied by spark discharge. When strong electricity flows out of date, the air expands rapidly, producing huge noise, that is, lightning. Lightning is a very destructive natural phenomenon, its voltage can be as high as millions of volts and instantaneous current can be as high as hundreds of thousands of amperes. For thousands of years, lightning has caused countless losses. Therefore, lightning disaster has become one of the most serious natural disasters in 10 announced by the United Nations. According to the characteristics and properties of lightning, lightning can be divided into direct lightning, lightning induction and lightning wave intrusion.

With the development of local economy and the improvement of people's living standards, the number of motor vehicles in various places has increased rapidly, and the number of motor vehicle gas stations that provide energy for them has also increased rapidly. Gas station plays an important role in urban traffic construction and is also an important energy base for urban disaster relief. However, in recent years, frequent lightning strikes at gas stations have directly threatened the safety of people and buildings around gas stations and weakened the function of gas stations as urban energy hubs. Therefore, comprehensive lightning protection of gas stations is very important.

2 gas station lightning zoning

2. 1 Environmental characteristics of gas stations

Gas stations are generally located on the side of roads, mostly isolated buildings in open areas, which are vulnerable to lightning strikes. Gas stations are flammable and explosive places. We should pay special attention to the lightning protection of gas stations, which usually have the following characteristics:

(1) Location: Gas stations are all built in open areas or suburbs of urban areas with convenient transportation, such as main roads, secondary roads and expressways, and the surrounding areas are relatively empty;

(2) The design of buildings against direct lightning is not standardized: some gas station buildings and sheds are not equipped with direct lightning protection facilities, and the exposed lightning protection leads are not grounded along the shortest vertical path of the external wall;

(3) Power supply system: Generally, the 380V AC power supply lines of gas stations are connected to the vicinity of the station area by overhead open wires and buried in buildings. Some gas stations are connected through overhead 10KV power lines, and then buried in the building through transformers. In rural and mountainous areas, sometimes there are no underground measures at all, no surge protector and repeated grounding, so it is very vulnerable to lightning wave intrusion and lightning electromagnetic pulse attack;

(4) Communication network system: ISDN, telephone lines, monitoring equipment and other weak current lines introduced into gas stations are usually introduced from outdoor overhead lines, and special signal surge protectors (SPD) are not usually installed as lightning protection measures;

(5) Electrostatic protection: The tanker or refueling gun of the gas station is not grounded or poorly grounded, and the resistance is too large, which does not meet the requirements of the specification. The breathing valve of the gas station is not bridged or the leapfrog resistance is too large;

(6) Generator grounding: Many gas stations have no generator grounding, which is not in line with safety production.

It is not difficult to find the above characteristics. From the point of view of lightning, gas stations generally operate in a "high-risk" environment, that is, the "exposure" of lightning damage risk is very high, and strong protective measures need to be taken. According to GB50057-20 10 code for lightning protection design of buildings, GB50343-2004 technical code for lightning protection of electronic information systems of buildings, GB50 156-2002 code for design and construction of automobile filling stations and iec 613/kloc-. However, the current situation is that some gas stations do not provide lightning overvoltage protection for power lines and signal lines, and the lightning protection design of buildings is not standardized, which has certain security risks.

In view of the above characteristics and requirements of gas stations, it is generally believed that for areas with moderate or above thunderstorm intensity (annual average thunderstorm days are more than 40 days), the surge protector with maximum nominal discharge current greater than 12.5KV( 10/350μS) should be selected as the primary lightning protection of power supply system, and its protection level should be less than 2KV to ensure the reliable operation of power supply of gas station equipment. Because the communication signal path mostly enters from the outside, it will also be threatened by lightning, so it is necessary to use special communication signal series surge protectors for lightning protection.

2.2 Lightning protection level of gas station

According to the Code for Lightning Protection Design of Buildings (GB50057-20 10), the annual estimated lightning strikes of buildings are calculated as follows: n = kngang = 0.1TD, where: n the estimated lightning strikes of buildings (times/a); K lightning frequency correction factor:

The annual average lightning strike density Ae in the area where the natural gas building is located is equivalent to the area where the building intercepts the same number of lightning strikes (km2); Td the annual average lightning days in this area;

The estimated number of times a building is struck by lightning every year is calculated as follows: n = kngang = 0.1tdk. The corresponding values are taken in the following cases: a. Isolated buildings in the wilderness take 2; B Brick-wood structure building with metal roof1.7;

C. For buildings located at the riverside, lakeside, under the hillside or in the mountains, with low soil resistance, exposed groundwater, the top of earth mountain, mountain valley wind and other places. And especially humid buildings, the value is 1.5.

The gas station is empty. In this case, the value of k is 2; According to the lightning frequency parameters of the above years, in the thunderstorm intensity area (the average thunderstorm day is more than 40 days), the estimated lightning frequency of a conventional gas station with an area of about 3,000 square meters and a building height less than 15 meters is N=kNgAe≈0. 15 times/a. ..

According to the above calculation, and referring to the requirements of Article 3.0.3 of Code for Lightning Protection Design of Buildings (GB50057-20 10), "Buildings with explosion danger are located in 1 zone or 2 1 zone, and electric sparks are not easy to cause explosion or cause serious damage and personal injury". Therefore, the lightning protection of automobile gas stations should be designed according to the second type of lightning protection buildings.

3 Lightning protection design of gas station

3. 1 lightning protection design of buildings (structures)

The buildings (structures) of gas stations are generally composed of awnings, office buildings, power distribution rooms and other ancillary buildings. According to the Code for Lightning Protection Design of Buildings (GB50057-20 10), it is determined that the lightning protection category of automobile gas station buildings is Class II buildings, and it is unnecessary to install lightning rods separately. Offices and ancillary buildings generally adopt reinforced concrete structures. Automobile refueling

Lightning protection and lightning arrester design for buildings (structures) in station yard: lightning arrester net (belt) installed on buildings or

Lightning rod or lightning receptor composed of it. Lightning strike zone shall be laid along the corner, roof, eaves and cornices of buildings vulnerable to lightning strike, and a lightning strike grid of not more than 10m× 10m or 12m×8m shall be formed on the whole roof. Gas station canopy generally adopts steel frame structure, and its roof adopts metal roof, which can be directly used as lightning arrester, and there is no need to set lightning rod or lightning belt (except other objects that need to be protected on the roof).

Design of lightning protection downlead for buildings (structures) in automobile gas stations: As the buildings (structures) in the station area generally adopt reinforced concrete structure and steel frame structure, the reinforced concrete structure should use two main tendons in the pile as natural downlead, and the spacing between downleads should not be greater than 18m, and the downlead should not be less than two, and should be evenly arranged around the building. The down lead is provided with several connecting plates at appropriate places, which can be used for equipotential bonding, and all electrical equipment and metal conductors in offices and affiliated buildings are equipotential bonded.

Design of lightning protection grounding device for buildings (structures) in automobile gas stations: Generally, natural grounding devices are used as grounding devices. Because the spacing of grounding devices in general gas stations is less than 5 meters, lightning protection grounding, anti-static grounding, electrical equipment working grounding, protective grounding, information system grounding, equipotential bonding belt, building metal components, etc. should all be grounded with * * * to realize voltage equalization and equipotential, so as to reduce the potential difference between various grounding devices and different systems. During the construction of building (structure) foundation, the steel bars in the two foundations should be reliably connected and grounded every 18m. When natural grounding body can't meet the requirements of grounding resistance, artificial grounding body should be set. Considering the long-term use and corrosion resistance of grounding device, it is suggested that the layout of grounding device should be designed according to the terrain, and the artificial grounding body should be set outside the apron slope protection of 1m, which will not damage the apron slope protection surface, but also increase the effective area surrounded by grounding grid. Setting a closed ring outside the building can play the role of equalizing ring, can also be used to introduce ground wires from different directions for equipotential connection, and can also be used as the external shielding ground wire of cables entering the building at different positions. Horizontal grounding usually adopts 40×4mm galvanized flat steel with a buried depth of 0.6 m (the depth should be greater than the local frozen soil layer); L50×50×5×2500mm galvanized flat steel is used for vertical grounding, and nonmetallic connection is used between vertical grounding bodies.

Grounding module. Grounding resistance requirements: the gas station grounding network is divided into four parts: direct lightning protection grounding (its grounding resistance is ≤10Ω), anti-static grounding (its grounding resistance is ≤100Ω), power supply working grounding grounding resistance is ≤ 4Ω) and signal line DC working grounding resistance is ≤ 4Ω). When unified grounding is adopted, the grounding resistance should be determined according to the minimum value.

3.2 Lightning protection design of oil tank farm

Lightning protection design of oil tank farm: Breathing valve (height 4-5m) is generally used for lightning arrester. When the breathing valve is used as a lightning receptor, it should be ensured that the breathing valve is in good contact with the tank, so as to prevent the breathing valve from discharging due to direct lightning and introduce lightning current into the earth. Buried metal oil tanks must be grounded annularly, with no less than two grounding points, and the arc distance between them should not be less than 30m, and the grounding body should not be less than 3m from the tank wall. When the roof thickness of steel oil tank is less than 4 mm, lightning protection facilities should be set up. When the roof thickness is greater than or equal to 4 mm, lightning protection facilities may not be installed. However, independent lightning rods should be installed as lightning protection facilities for oil tanks and aluminum-topped oil tanks located in many minefields (the average number of thunderstorm days per year is more than 40 days). The horizontal distance between the independent lightning rod and the protected oil tank should not be less than 3m. According to the rolling ball method, the oil tank breathing valve should be within its protection range, and the protection range should be more than 2m higher than the breathing valve.

The beginning, end, bend and branch of the oil pipeline shall be grounded separately, and the grounding resistance per 12m shall be ≤ 4Ω. * * * The grounding device is adopted for the oil tank area, and equipotential connection is made everywhere, namely, the tank body of the oil tank, metal parts of the oil tank, metal accessories such as breathing valve and oil measuring hole, power cable sheath and porcelain needle, information system distribution cable sheath installed on the steel oil tank, oil tank anchor screws, etc. It should be reliably electrically connected with the grounding system, and the grounding resistance value should be ≤ 4Ω, because the oil in the oil tank will generate static electricity when loading and unloading oil. Special grounding wire, clamp and grounding terminal should be used for the connection between oil tank and loading and unloading equipment, and the anti-static grounding device should be connected to the oil tank. The tanker main body should be reliably connected with the trench grounding device, and one end of the copper wire in the hose of the refueling gun should be connected with the tanker main body to prevent the static electricity generated by the friction between gasoline (or diesel oil) and the refueling gun from being released through the refueling pipe. When the metal sheaths of pipes, frames and cables laid in parallel are long metal objects, when the clear distance is less than 100mm, metal wires should be used for jumper, and the spacing between jumper points should not be greater than 30m. When the clear distance between bridges on that day is less than 100mm, their intersections should also be bridged. When there are less than 5 connecting bolts for flanges of various metal pipes, the flanges must be bridged by metal wires, and the bridging resistance should be less than 0.03 Ω.

3.3 Lightning protection design of distribution system

TN-S distribution coefficient should be adopted in 380/220V power supply and distribution system, that is, three-phase five-wire system (single-phase three-wire system) distribution mode. In the whole system (including branch lines) of this distribution mode, there are separate neutral wires (N) and protective grounding wires (PE), that is, the neutral wires and protective grounding wires are always separated in the whole system. The purpose of separating the N line from the PE line is that there is no alternating current flowing on the PE line, and it is reliably connected with the equipotential bonding grounding system in the whole lightning protection project, so the potentials on the PE line are equal everywhere.

The cable should be buried in the gas station through steel pipes, and both ends of the cable metal sheath or cable metal protection tube should be grounded. The power supply end of the power supply and distribution system shall be equipped with an overvoltage (surge) protector suitable for the withstand voltage level of the equipment. In the power supply system, both ends of cable metal sheath or cable metal protection tube are grounded, with the purpose of shielding electromagnetic effect, reducing or weakening lightning damage and preventing lightning accidents. Cables of power supply system shall be wired separately, and shall not be laid in the same trench as oil products, liquefied petroleum gas, natural gas pipelines and heating pipelines, so as to prevent the cable trench from entering explosive gas mixture and avoid the mutual influence between cables and pipelines, resulting in explosion and fire accidents, and the cable trench shall be filled with sand.

4 Lightning protection design scheme of gas station beside expressway in Yuyao City

4. 1 gas station environmental investigation

The gas station is located in Yuyao City, Zhejiang Province, with a monsoon subtropical climate. Its soil properties are giant slab soil and sandstone land, and the soil resistivity is large and uneven. The average value after measurement is180 Ω m. The annual average thunderstorm days are 40d/ year. There is a high probability of thunderstorms from March to September, which belongs to multiple minefields. There are fuel sheds and office buildings in the gas station, both of which are reinforced concrete structures. The refueling shed is 20 meters long, 20 meters wide and 8 meters high, and there are 4 tankers in it, each with an interval of 6 meters. Office length 16m, width 23. 1m and height 3.5m. There are two underground oil depots 0/0 meter away from the office/kloc-. The power supply line adopts overhead introduction, and the power supply system adopts TN-S system. There are telephones, photocopiers, UPS, data transmission lines, air conditioning machines and other electronic equipment in the office. According to GB50057-20 10 Code for Lightning Protection Design of Buildings, gas stations belong to the second type of lightning protection buildings.

4.2 Design of this gas station

According to the above knowledge, this building is a type II lightning protection building, so the lightning protection design is carried out according to the type II lightning protection building (TN-S system is adopted): φ 1.3mm galvanized round steel is used for exposed protection around the canopy and the roof of the office building, and the roof is not more than10m×12m×. In addition, the metal components protruding from the roof should be reliably welded with the roof lightning protection zone. When the nonmetallic objects protruding from the roof are not within the effective protection range of the lightning arrester, a direct lightning protection device (lightning arrester or lightning arrester or hybrid lightning arrester) should be installed for protection. According to the characteristics of reinforced concrete frame outside the building, when the steel bars in the concrete are used as natural downlead and the foundation grounding body is used at the same time, connecting plates should be set at appropriate positions indoors and outdoors. Copper-zinc alloy welding, fusion welding, pressure welding, sewing, screws or screw connection can be used. The down lead of the second lightning protection building should be evenly and symmetrically arranged around the building, and the spacing along the perimeter should not be greater than 18m. Lightning protection grounding device should make full use of the main reinforcement of pile foundation and pile cap structure to form a natural grounding device, and use the two diagonal main reinforcement of the main reinforcement of the peripheral structure as the vertical grounding body of each pile foundation; The main reinforcement of the outer ring beam of the structure should be welded and connected into a horizontal grounding body.

In this project, the exposed process pipelines such as anti-static grounding, breathing valve, tank car and buried oil tank are electrically connected with each other and then connected with lightning protection grounding with grounding device. The impact grounding resistance of * * * is less than 1 ohm. If it does not meet the requirements, an artificial grounding electrode should be made. According to the environmental investigation, the cables of the building are introduced from overhead, so a section of metal armored cable or sheathed cable should be buried directly through steel pipes when entering the building, and the distance between the overhead line and the building should not be less than 15m.

In order to prevent lightning induction, according to the requirements of GB50343-2004 Technical Specification for Lightning Protection of Building Electronic Information Systems, a first-class surge protector (technical parameters: Iimp≥ 12.5KA, Up≤2.5KV) is installed in the main distribution box for protection. 5 concluding remarks

As a lightning high-risk area and inflammable and explosive place, automobile gas stations should be considered according to the protection requirements of Class II lightning protection buildings, and pay attention to the comprehensive protection such as equipotential connection and grounding system, shielding and wiring, lightning protection and grounding, and installation of surge protectors. In the actual lightning protection engineering design, it is necessary to use flexibly and comprehensively according to the characteristics of various devices and the actual situation of the protected objects, so as to achieve good results and minimize lightning disasters. refer to

1 Code for Design and Construction of Automobile Filling Stations GB50 156-2002. 2 Code for Lightning Protection Design of Building Electronic Information System GB50343-2004 3 Code for Lightning Protection Design of Buildings GB50057-20 10. China Planning Press. 20 1 1 year: (189pp)

4 Xiao Xiaoqing. Fundamentals of lightning and protection technology. Meteorological press. 2006: (176 pages)

5 Meijiang. Lightning protection engineering and design of buildings. Meteorological press.

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