LIGHTING PROTECTION OF A GAS BOILER ROOM

Gas candles in boiler rooms require particularly reliable lightning protection. The reason is clear - a direct lightning strike into an object can instantly lead to fire and explosion.

Recently, the ZANDZ Technical Center received the task of calculating the lightning protection of gas candles in a boiler room, ensuring a system reliability of at least 0.95. Our technical experts offered a solution, which we are sharing with you.

Example of calculation of lightning protection of a gas boiler

Object: Boiler room.

Figure 1 - Object plan

Task: Perform calculations of the lightning protection system of a gas boiler.

Protection of buildings and structures against lightning discharges is ensured by lightning rods. A lightning rod is a device rising above the facility that diverts lightning current into the ground without entering the facility. It comprises a lightning rod that directly receives the lightning discharge, a down conductor and a ground electrode.

Solutions to meet the requirements for a lightning protection system:

1. Lightning protection is carried out in accordance with EIC 7th edition., IS 153-34.21.122-2003 "Instructions for lightning protection of buildings, structures and industrial communications" (hereinafter IS) and AD 34.21.122-87 "Instructions for lightning protection of buildings and structures" (hereinafter AD).

2. The object refers to category 2 of lightning protection. System reliability must be not less than 0,95.

3. Lightning protection of the facility is performed using 3 vertical lightning rods-masts with a height of 2 m on chimneys (GL-21101G);

4. Downdrop of down conductors and connection to the existing grounding device.

Results of the calculation carried out with the software developed by the JSC "Energy Institute to the name of G.M. Krzhizhanovsky (OJSC "ENIN"):

Density of lightning strikes into the ground - 4 strikes / sq. km per year;

The total number of strikes into the system - 0,23 (once in 4 years);

The total number of breakthroughs is 0.011 (every 91 years);

The reliability of the system is 0.952;

Probability of a breakthrough into all the system objects - 0.048.

Figure 2 shows the arrangement of equipment.

Table 1 gives the list of the required equipment and materials.

Figure 2 - Location of equipment for lightning protection of gas candles.

Table 1 - List of need in materials.

 № Image Product item Product Quantity, pcs 1. GL-21101G GALMAR Vertical lightning rod (air terminal- mast) (2 meters) 3 2. ZZ-203-002 ZANDZ Fastening for a lightning rod to the chimney (stainless steel) 3 3. ZZ-202-001 ZANDZ Clamp to the lightning rod for down conductors (stainless steel) 3 4. GL-11149-50 GALMAR Copper-coated wire (D 8mm / S 50 mm²; coil of 50 meters) 2 5. GL-11149-20 GALMAR Copper-bonded wire (D 8mm / S 50 mm²; coil 20 meters) 2 6. GL-11551A GALMAR Clamp for connecting down conductors (painted galvanized steel) 3 7. GL-11562A GALMAR Control clamp for connecting down conductors, wire + tape (painted galvanized steel) 3