Design of automatic fire extinguishing installations with finely sprayed water. Water mist fire extinguishing systems (WMA)

The automatic fire extinguishing system with finely sprayed water (ASP TRV) allows the use of water as a fire extinguishing agent with maximum efficiency.

When used in this way, most of the disadvantages of water are reduced to minor consequences.

Operating principle

1. Special fire detectors various types determine the source of the fire and, if possible, its location.
2. Triggered system fire alarm sends an alarm signal to the console and activates the locking and starting device on the main module.
3. The shut-off and release device opens a channel for gas to enter the water cylinder, where a gas-liquid composition with additional fire extinguishing additives is formed.
4. The mixture is supplied under pressure to the spraying devices through a pipeline.
5. Control of the release of finely sprayed water is carried out automatically and remotely using pressure detectors, which are located at control points on the pipeline.
6. When the limit pressure in the water container is exceeded, the safety system is activated, and part of the gas is released through the safety device - safety valve.

In standby mode, gas does not flow into the water container, therefore, the main cylinder is not under pressure, which increases the duration of operation of the entire system.

The size of a drop of finely atomized water is about 100 microns. Under influence high temperature The water turns into steam, which blocks the flow of oxygen to the fire. The effectiveness of extinguishing an average source of fire is 1 minute. The steam-water suspension remains in the air of the room, depending on the movement of air currents, for up to 15 minutes, which prevents the reoccurrence of a fire.

In addition to extinguishing the fire, the finely dispersed water mixture precipitates most of the particulate matter in the smoke, significantly reducing smoke levels.

Area of ​​use

Using a water mist fire extinguishing system high pressure regulated by SP 5.13130.2009. They are used to extinguish fires of categories A, B and C. However, their use is allowed in rooms where electrical installations with voltages up to 1000V are located. ASP TRV is recommended to be installed at the following facilities:

• Multi-level indoor parking;
• Production and warehouse premises;
• Archives, library collections and book depositories;
• Cultural and entertainment complexes:
  • Theaters and cinemas;
  • Galleries;
  • Exhibition centers and pavilions;

• Retail and office premises;
• Hotels.

Advantages

The performance characteristics of water mist fire extinguishing systems significantly exceed those of conventional systems comparable cost, similar functionality.

• High fire extinguishing efficiency. The consumption of water with special fire extinguishing additives does not exceed 1.5 liters. per 1m2 of controlled premises;
• Absolute safety for people who are in the room. The extinguishing process can begin immediately after a fire is detected without waiting for personnel to evacuate.
• High smoke deposition ability;
• Environmentally friendly, subject to the use of certified fire extinguishing additives;
• Independence from external sources water;
• Compactness, possibility of placing main pipelines or modular units behind suspended ceilings, which preserves the interior design.
• Reusable with minimal costs to restore functionality.

System structure and design features

Rules and technical specifications project, and the installation sequence are regulated by Federal Law (FZ) No. 69 of December 21, 1994 and No. 123 of July 22, 2008. As well as technical standards SP 5.13130.2009, NPB 88-2001 and some others.

1. Tank for storing water with added fire extinguishing agents;
2. A device that forms a gas-liquid mixture;
3. Siphon intake tube;
4. Fastening tape;
5. Drain plug (bolt);
6. Safety relief valve;
7. Gas cylinder for mixing and displacing water;
8. Locking and starting device;
9. Brackets for attaching a gas cylinder to a container of water;
10. High pressure hose for supplying gas to the mixer;
11. Intermediate fitting;
12. Tee for connecting a pressure alarm and ;
13. Pressure alarm;
14. Interfloor covering;
15. Supply pipeline;
16. Sprayers;
17. Tee;
18. Distribution pipes;
19. Place for refilling fire extinguishing agents;
20. Targeted delivery device;
21. High pressure hose.

Despite the ease of installation of the system, if its design and installation is carried out by inexperienced engineers, mistakes may be made that will lead to unjustified complication, increase in cost or decrease in operating efficiency.

The most common mistakes:

• Installation of autonomous modules or a central unit with water and gas of a smaller volume than required for a room of this type;
• Using pipes without zinc or any other protective coating for pipeline installation;
• Exceeding the distance of placement of water and gas cylinders from each other and from the controlled premises;
• Placing a water cylinder below the permissible level;
• Incorrect distribution of extinguishing zones (placement or direction of sprayers).

Types of automated water mist fire extinguishing systems

Classification by type of launch:

1. – non-automatic spray nozzles are used. Activation is accomplished by opening the main control valve.
2. – use automatic sprinklers. There are two types of sprinkler systems:
   1. Water-filled - there is always water in the pipes supplying water to the sprinklers. Extinguishing begins immediately after the alarm is triggered.
   2. Air-filled - water fills the pipes only up to the control valve. Supply into the distribution pipeline is carried out only after the sprinklers are activated.

   The delay time for the start of the fire extinguishing process of an air-filled system is insignificant, and the resistance of the pipeline to corrosion processes increases significantly.

3. Preliminary action is a type of air-filled sprinkler system, equipped with fire detection detectors. At their signal it opens stop valve, and the fire extinguishing mixture enters the pipes. However, the fire extinguishing process begins only after the sprinklers are activated.

Depending on the operating pressure, systems are distinguished:

• With low pressure - up to 12.1 atm.;
• With average pressure - 12.1 - 34.5 atm.;
• With high pressure - more than 34.5 atm.

The difference between a deluge and a sprinkler nozzle is that the latter has a low-melting polymer insert or a glass flask with a heat-sensitive substance inside. When the threshold temperature increases, they open, freeing the nozzle for water supply.

Sprinklers:

Autonomous water mist fire extinguishing modules

Fire extinguishing module with fine spray water TRV Garant 30.

Installed in rooms with a class fire danger F1 - F5. It is used in extinguishing fires of categories A and B with electrical equipment turned on with voltage up to 1000V. The duration of the fire extinguishing process is at least 5 seconds, during which time the device emits 30 liters. water with added fire extinguishing agents, the proportion of which should be 0.3 kg. The service life of the device is 10 years and it can be reused up to 5 times. The module operates at an operating temperature range of +5 - +50°C.

Modular water mist fire extinguishing installation Typhoon.

Used to extinguish class A1, A2, B1, B2 fires. A special feature of the device is the presence of four multi-directional spray nozzles, which increase the coverage area of ​​the water suspension. Depending on the height of the device, 2-8 m, it can effectively treat an area of ​​6-20 m2. Time efficient work installation takes 3-6 seconds, depending on the number of spray nozzles.

Extinguishing fires using modules or fine spray systems is very effective, but can only be used in heated rooms.

IN Lately on new construction sites and sites undergoing reconstruction, the use of the most modern system fire extinguishing with finely sprayed water.

TRV ( water mist) is an almost ideal system. With high fire extinguishing efficiency, the consequences of using expansion valves are minimal. In addition, modular expansion valve systems are autonomous and do not require either an electrical supply or additional water tanks. Not the least factor is that TRV is essentially harmless to humans. All this suggests a wide field for using these settings.

EI FOG "Water Mist" systems are absolutely new concept fire extinguishing, where as fire extinguishing agent water is used, supplied under high pressure to produce droplets no larger than 100 microns. This system provides the following advantages:

• reducing the cost of purchasing tanks and water storage tanks;
• there is no need to section the protected volumes, just like when using volumetric extinguishing installations;
• minimizing the damage caused by the fire extinguishing agent, for example, the damage caused by water when the sprinkler or deluge installations of conventional spray are activated, with a droplet diameter of 0.4 - 2 mm.

System EI FOG "Water Mist" promotes the creation of fine mist, which quickly fills the protected volume of the room, while reducing the oxygen concentration. The effectiveness of fire extinguishing increases significantly when using minimal amount water.

Thanks to such a significant reduction in the amount of water consumed, compared to conventional sprinkler systems, the damage caused during fire fighting is minimized.

Water mist has a high heat capacity and a significant total active surface area of ​​the droplets, which makes it possible to sharply reduce the temperature in the fire zone and stop the chemical combustion reaction.

All these factors make it possible to safely evacuate people who were in the room, as well as create conditions for normal operation special personnel equipped with portable fire extinguishing equipment.

Due to the fact that fire extinguishing systems EI FOG "Water Mist" do not contain chemical additives, the installation can be considered absolutely environmentally friendly.

All of these advantages contribute to ensuring that fire control and extinguishing processes are carried out in the best possible way.

Using the EI FOG System

Automatic fire extinguishing installations with finely sprayed water ei fog water mist are used to extinguish fires of classes A (solid combustible materials), B (flammable liquids), C (flammable gases) and E (electrical installations under voltage up to 1000 V) in buildings, structures and premises for various purposes with fire hazard categories A, B, B1 and B3. The system can be used to extinguish live cables up to 30,000 V.

This fire extinguishing system, which uses water mist, complies with international standards IMO A 800, A 913 and NFPA 75. Currently, the system is certified by the Federal State Institution VNIIPO EMERCOM of Russia.

Compare the advantages of a fire extinguishing system based on expansion valves over traditional water fire extinguishing systems:

Usage automatic installations fire extinguishing with finely sprayed water (AUPT TRV), both with and without additives, is a common practice today. The use of such fire extinguishing systems has proven to be an effective and cost-effective method of fire extinguishing, both in terms of installation and maintenance costs.

The effectiveness of using TRV is due to the following. The combustion mechanism is based on a combination of a number of factors: the presence of fuel, oxygen and high temperature. Accordingly, to extinguish it, it is necessary to lower the temperature in the combustion zone, reduce the oxygen concentration and isolate the source of the fire from access to oxygen. To effectively suppress combustion, it is necessary to reduce the temperature in the combustion zone. A sharp cooling of the combustion zone can lead to a complete cessation of combustion. By dilution we mean a decrease in the oxygen content in the combustion zone to such values ​​at which the combustion process begins to slow down and die out. Insulation means limiting the access of oxygen to the combustion zone, which leads to the slowdown and extinction of the fire. Insulation can be provided by the properties of OTV. For example, the extinguishing composition OTV-V1, developed by LLC NPK Technologies and Fire Extinguishing Systems, has additives that form a film on the surface of the protected object. This film retains its properties for at least 15 minutes and, thus, isolates the source of fire from access to oxygen, preventing it from re-igniting.

When water enters the fire area, it boils. There is a powerful removal of heat from the combustion zone. In addition, due to the fact that the expansion valve has a droplet size tens of times smaller in diameter compared to the droplet size of sprinkler AUPTs, the surface area of ​​the water that comes into contact with the fire zone increases hundreds of times, and the number of drops in 1 liter of water increases thousands. Abundant vaporization occurs, which significantly reduces the oxygen concentration in the combustion zone. Thus, when using expansion valves, the amount of water required to extinguish the fire zone is reduced tens of times. For example, to extinguish a medium-sized room, several tons of water will be required in the case of using sprinkler automatic fire extinguishing devices, and several tens of liters in the case of using automatic fire suppression valves. When extinguishing the TRV important issue is the “delivery” of a small drop to the combustion zone, because powerful convection currents of hot air prevent this, reducing the effectiveness of extinguishing. Droplet weighting is achieved by the design of nozzles and the use of various additives. For example, LLC “NPK “Technologies and anti-aircraft systems” fire safety» has developed and patented an original extinguishing composition, OTV-V1, and a KSP sprayer, which, in combination with a modular installation, form a complex that ensures the “transportation” of a drop of water into the combustion zone, increasing the efficiency of the extinguishing composition and extinguishing in general.

The use of TRV has a number of significant advantages compared to other AUPTs.

• complete autonomy from external sources. The TRV system does not require a connection to a pipeline or to electricity according to the 1st category. Modular AUPT TRVs with additives based on MUPTV 100-G-VD, produced by LLC NPK Fire Safety Technologies and Systems, are used at facilities where there are no Vodokanal water limits. Modular installations do not require water storage tanks, water supply pumps, or other additional equipment.
• high extinguishing efficiency combined with low consumption of fire extinguishing agent (almost a hundred times lower traditional ways water fire extinguishing).
• safety when exposure to expansion valves affects people and protected objects.
• long-term insulating effect on the fire object. For example, when extinguishing using a TRV installation with additives based on MUPTV100-G-VD “Nimbus”, low expansion foam is formed at the output (the advantages of TRV extinguishing and foam extinguishing are combined). Upon completion of the installation, the foam remains on the surface of the protected object for at least 10-15 minutes, which is especially important for suppressing smoldering processes and preventing re-ignition.
• The AUPT TRV easily returns to operating condition after activation. It is necessary to fill the OTV modules and pump up the pressure using compressor or other source of compressed air;
• The expansion valve has a high smoke settling ability, which is especially important for facilities with large numbers of people.

Today, expansion valve systems are widely used to protect various types of objects.

Living spaces.

Objects with large numbers of people: offices, shopping and entertainment centers and shopping centers.

Cultural objects- museums, art galleries, libraries.

Athletic facilities(rooms under the stands, gyms).

Industrial premises for various purposes. For example, LLC NPK Fire Safety Technologies and Systems has experience in protecting LNPP-2 facilities with modular AUPT TRVs with additives, and has successfully tested its AUPT TRVs when extinguishing electrical equipment with voltages up to 72 kV. The company's assets include the protection of facilities of the State Corporation Rostat, Zarubezhneft, Distillery, etc.

Archives, covered parking lots and parking lots, transport facilities, zoos, stables- far from it full list objects where AUPT TRV will find application. It is necessary to especially note the convenience of modular AUPT TRVs with additives, which consists in the fact that a battery of modules can be installed in any place convenient for the customer, without taking up “vital” space.

The design of fire extinguishing systems based on expansion valves is regulated by the STO (Organization Standards) of the manufacturer of expansion valve installations, as well as SP5.13130.2009.

There are AUPT installations where powder and gas are used as waste water, which in some cases have advantages over water. Nevertheless, the most common stationary fire extinguishing systems are still water-based.

The explanation for this lies on the surface, or rather, it flows from every water tap - accessibility, low cost even with huge costs, volumes for localization/liquidation, practically unlimited or quite sufficient reserves for these purposes in external networks, fire reservoirs (reservoirs).

It's simple:

• After the activation of thermal, flame detectors, and in some cases in industrial premises that have a high category of explosion and fire hazard, explosion-proof fire detectors, the APS device sends a control signal to turn on the locking mechanism of the starting cylinder of the AUP-TRV extinguishing module.
• It is also possible to start the operation of the extinguishing system with sprayed water using , performing the function of a starting device for the installation (module) / AUP-TRV system.
• The displacing gas enters the tank with OTV (purified water, often with special additives).
• The resulting fire extinguishing mixture under pressure enters the distribution (supply) and then into distribution pipelines mounted under the ceiling of the protected room, to sprinklers that emit the mixture in the form of finely atomized water, often called water mist, which effectively suppresses the source of the fire.
• Control/monitoring of the release of exhaust gas is carried out automatically, remotely, according to the readings of the mixture pressure indicator installed on the supply pipeline of the installation module. When the control value of the pressure in the waste water tank is exceeded, the safety valve (membrane) is activated.

Modular

According to paragraphs. 3.45, 3.47 SP 5.13130 ​​a module is a single device that implements the functions of storing/supplying fire extinguishing agents after a trigger signal is given, and a modular extinguishing installation is several modules with common system fire detection and control/control of their launch.

In addition to the basic version - with a propellant gas cylinder, modular AUP-TRV, as well as TRV fire extinguishing modules, are of the injection type; when the OTV in the product is immediately under pressure and ready for use, which reduces the response inertia of an individual device and the AUPT system as a whole.

It is convenient to protect small premises and buildings with such equipment – ​​modules, such as modular installations/fire extinguishing systems of TRV.

Automatic

Designed for surface local extinguishing of fires of class A, B, as well as electrical equipment with voltage up to 1 thousand V.

AUP-TRV, according to both domestic and foreign experts, is effective for protecting the following objects, individual important premises in them:

• Residential buildings, apartments.
• Kindergartens, nurseries.
• Nursing homes, boarding schools.
• Educational institutions.
• Hospitals, hospitals.
• Hotels, resorts, sanatoriums, hostels.
• Industrial kitchen equipment.
• Cabins, engine rooms, corridors of ships/ships.

As can be seen from the list, these are mainly residential premises of small area and height with a low fire load. The priority of using finely sprayed water instead of sprinkler/drencher installations, and even more so powder and gas ones, is quite clear - this is to ensure the safety of people.

Although manufacturers advocate the widespread use of AUP-TRV for extinguishing shopping and office centers, underground parking lots, industrial/warehouse premises, cable tunnels, archives, museums and book depositories, even oil and gas industry facilities (!), experts consider this to be nothing more than an advertising message owners of buildings/structures, management of enterprises and organizations.

In most cases, traditional water installations do a good job of extinguishing such objects, and for extinguishing specific, especially important premises, powder and gas systems fire extinguishing; and the use of AUP-TRV there, as confirmed by calculations, is ineffective. To understand when and who needs systems, AUP-TRV modules are worth comparing the pros and cons of their acquisition and use.

Advantages and disadvantages

First of all, about the advantages:

• Modules and AUP-TRV installations are ready-made, complete equipment that can be quickly installed on site, compared to the installation of, for example, a fire sprinkler system.
• Due to the fact that the water mist sprayed by the sprinklers of the modules/installations is not dangerous for people’s breathing, it is possible to evacuate the protected premises during operation of the AUP-TRV.
• Minimal damage to the contents of the premises, compared to deluge/sprinkler and powder systems fire extinguishing
• The equipment of modular AUP-TRV requires minimal control/maintenance, similar to the maintenance of portable/mobile fire extinguishers, and planned Maintenance not unlike recharging fire extinguishers.

As usual, there were some drawbacks:

• In contrast to the usual deluge, sprinkler water AUPT, the supply of fire extinguishing agent, displacing gas, therefore, the operating time of the expansion valve extinguishing module/installation is limited. It may not be enough to extinguish the fire, in best case scenario will be enough to localize it. Although there are installations with a compressor method of supplying the displacing agent, the complexity of the system will significantly affect the price of the products, and will also require expensive water treatment so that the small holes of the sprinklers are not clogged with mechanical impurities and mineral sediments.
• The high cost of a set of equipment is a problem with most domestic manufacturers, not to mention foreign companies.
• The need to install APS in protected areas, which is not necessary when choosing a sprinkler water system.

Conclusions: The choice of modules and TRV fire extinguishing installations should be made by the owner or manager of the protected facility based on design decisions or the conclusion of specialists in the field of fire safety, and not on advertising brochures from manufacturers who call such fire extinguishing systems universal.

Features of fires in hotels
Modern hotel complexes are usually located in multifunctional high-rise buildings. Besides hotel rooms they include premises for other functional purposes: administrative, sports, cultural and leisure, service, healthcare, educational, utility, parking, etc.
Today, the hotel industry is characterized by a high degree of automation and a tendency to minimize service personnel.
Features of fires in hotel complexes include the following:
there are a large number of people in the building at the time of the fire;
fires often occur at night, and most of them start in rooms with limited access to people;
The duration of fire extinguishing is approximately 3 to 5 hours;
fire causes great material damage. Fires that occurred in hotels are divided into the following main groups: fires caused by smoking;
fires that occurred during hotel renovations;
fires caused by incandescent lamps;
fires caused by violations of fire safety rules during installation electrical appliances;
fires in kitchens;
fires in areas where people live.

Typically, a fire occurs due to non-compliance with fire safety measures. And, despite the fact that they are clearly stated by law, many premises owners ignore them. However, statistics show that every hour one person dies in a fire and another 20 receive burns and injuries of varying severity, and every 5 minutes a new fire starts in the country. Hotels and hostels belong to the zone increased risk- these are buildings in which there are always a lot of people, and many of the guests, while on vacation, lose their vigilance and neglect basic fire safety rules.

Rationale for using TRV Fire extinguishing with finely sprayed water in hotels is especially important, since it is there that high extinguishing efficiency is required and minimizing damage from water spills is important.
Usually indoor fire hotel complexes develops according to the following scenario:
During the first 10–20 minutes, the fire spreads linearly along the combustible material. At this time, the room is filled with smoke and it is impossible to see the flames. The air temperature in the room gradually rises to 250–300 degrees. This is the ignition temperature of all flammable materials.
After 20 minutes, the volumetric spread of the fire begins. After another 10 minutes, the glazing begins to fail. Inflow increases fresh air, the development of the fire increases sharply. The temperature reaches 900 degrees.
Burnout phase. Within 10 minutes it is achieved maximum speed fire.
After the main substances burn out, the fire stabilization phase occurs (from 20 minutes to 5 hours). If the fire cannot spread to other rooms, the fire goes outside. At this time, the collapse of burnt out structures occurs. That is why it is of great importance to have in the building automatic system
fire extinguishing
At the same time, the water fire extinguishing system has a number of disadvantages:
– causes damage to property and interiors by spilling large amounts of water;
– due to the high intensity of irrigation, powerful pumps and large diameter pipes are required.
The average time to extinguish a fire when using fire extinguishing installations with finely sprayed water is several minutes, the estimated operating time of the installation is 10 minutes, thus, the fire is extinguished at the stage of the first phase, which makes it possible to almost completely avoid the consequences of the fire for people and material assets.
The demand for water mist equipment is growing every year. Both modular installations of finely sprayed water and automatic installations for extinguishing fires with finely sprayed water of an aggregate type have found widespread use.
Water mist fire extinguishing installations are divided into 2 types:
modular (with cylinders);