I. Introduction to IG100 gas fire extinguishing system

1.1. There are clear regulations on the application of gas fire extinguishing system in our country. GB50016-2006 "Code for Fire Protection Design of Buildings", GB50045-2005 "Code for Fire Protection Design of high-rise Civil Buildings", GB50098-98 "Code for Fire Protection Design of Civil Air Defense Engineering" and other national standards require communication room, computer room, archive library, etc. Gas fire extinguishing equipment should be installed in places with valuable equipment such as libraries and power generation rooms. Since the Montreal Agreement was signed, ozone-damaging fire extinguishing agents such as Halon 1211,1301 and others have gradually been replaced. With the deepening of the research on Halon alternative gases, nitrogen as an inert gas extinguishing agent has attracted wide attention, and the corresponding research on the extinguishing concentration, pressure and extinguishing effect of nitrogen extinguishing system has been carried out. IG10 nitrogen extinguishing system uses pure nitrogen from the atmosphere as extinguishing agent. IG10 is the main component of air, ozone depletion potential ODP = 0, greenhouse effect potential GWP = 0, atmospheric life is zero, no adverse impact on the environment.

1.2 IG100 colorless, tasteless, non-toxic, not only harmless to human body, and in the process of fire extinguishing does not produce any chemical substances, will not cause secondary pollution to the equipment, spraying without atomization phenomenon, no harm to the field of vision, can ensure that personnel orderly and safe evacuation. IG10 is 0.97 relative to air, so that it can maintain a constant extinguishing concentration after release in the protection zone, so as to ensure the extinguishing effect and effectively prevent reignition. It is a kind of safe and environmental protection fire extinguishing agent, which is suitable for the place where people are often active.

Ii. Characteristics of nitrogen fire extinguishing agent

2.1 The extinguishing agent of IG100 nitrogen fire extinguishing system is nitrogen, and its code is IG100 according to NFPA2001. Nitrogen is a component of the air, colorless, tasteless, non-corrosive, non-conductive, no residual after spraying. In addition to being an environmentally friendly gas, nitrogen has the following advantages:

2.2 Nitrogen does not change the chemical properties of air; Its GWP and ODS are both 0. In other words, it does not destroy the ozone layer and cause no greenhouse effect. Nitrogen does not react with other substances or mixtures. It retains its chemical properties after use and will not cause secondary pollution to other substances. (In any environment, the chemistry is the same).

GWP -- greenhouse potential

ODP - ozone layer depletion potential

2.3 Nitrogen is not a composite product; Nitrogen does not use chemical reagents in the production process. There is no chemical reagent residue. It is extracted from the dry air and concentrated and liquefied through special process towers.

2.4 The power consumption cost of nitrogen production is acceptable; The power consumption cost of concentration and liquefaction is about 1 KWH per cubic meter, and the N2 produced is of high purity without additional purification costs.

2.5 When IG10 is sprayed, there is no atomization phenomenon, which does not affect the visual field and facilitate personnel to evacuate calmly and safely. It does not produce cold condensation, and will not cause damage to the equipment due to sudden temperature changes

2.6 IG10 is chemically inert and will not decompose into any substance when exposed to high temperature or fire source. It has good electrical insulation performance and is very suitable for rescuing Class E live fire and protecting high-value irreplaceable equipment.

Three, fire extinguishing principle and application

IG100 nitrogen extinguishing system adopts the "full submerged" immersion extinguishing principle, so that the oxygen concentration in the protected area is reduced to less than 15%, so that the fire is extinguished. The fire extinguishing principle of nitrogen is physical fire extinguishing. When extinguishing a fire, spray it into a closed protection area to reduce the indoor oxygen concentration to less than 15%, so that combustion cannot be supported. Nitrogen does not react with any substances in the protected area, and is returned to the atmosphere after spraying without any residue.

IG100 Nitrogen fire extinguishing system is suitable for extinguishing the following types of fires:

- Electrical and electronic equipment fire;

- Flammable and flammable gas and liquid fires;

- Solid fire, such as floor, ceiling;

- Buildings with high value equipment and installations (e.g. CED, control rooms, etc.); - Demanding cultural venues (libraries, museums, etc.);

IG100 nitrogen extinguishing system is not suitable for the following fire situations:

- Chemicals or chemical mixtures that oxidize rapidly in the air, such as nitrate fibers, gunpowder, etc.

- Active metals such as lithium, sodium, potassium, magnesium, titanium, uranium, plutonium, etc.

- Chemicals that decompose thermatively themselves, such as certain organic peroxides or ammoniates.

Four, nitrogen fire extinguishing agent on the human body

When spraying fire extinguishing agent to extinguish fire, the protection area shall be closed. If there are personnel working occasions, the fire extinguishing agent will have a certain impact on the safety of personnel. The national standard GB50370-2005 "Code for Design of Gas Fire Extinguishing System" stipulates that the design concentration or actual use concentration of fire extinguishing agent in the protected area should not be greater than the toxic reaction concentration (LOAEL concentration).

The effects of nitrogen extinguishing agent on human body are as follows:

NOAEL=43%

LOAEL=52%

NOAEL - no toxic reaction concentration, the maximum concentration at which a physiological reaction from the toxic effects of a fire extinguishing agent cannot be observed.

LOAEL - toxic reaction concentration, the minimum concentration at which a physiological reaction from the toxic effects of a fire extinguishing agent can be observed.

Therefore, when the design concentration of IG100 nitrogen fire extinguishing system is less than 43%, no adverse effects of fire extinguishing agent on human body are observed. When the concentration of nitrogen in the protected area exceeds 53%, the human body is affected. ROTAREX Fire's global headquarters has conducted numerous experiments on the effects of nitrogen systems on the human body and has reached the following conclusions:

When the fire extinguishing system is working, personnel must evacuate within 5 minutes if the maximum concentration of IG100 gas is 43% in the area or room protected by the system.

2. When the fire extinguishing system is working, the maximum concentration of IG100 gas can be 43% ~ 52% when the protection area is less but there is a danger of exposure in the fire protection area. The staff must be evacuated within 3 minutes.

3. When the maximum concentration of IG100 gas is 52% ~ 62%, if there is no staff, but there is a risk of exposure in the protected area, do not stay in this area or room for 30 seconds.

4, the protection area has no staff, and no exposure to the danger in the fire zone, then the maximum concentration of IG100 gas can reach more than 62%.

V. Technical parameters table

The main performance parameters are shown in the following table: