Fire alarm, notification and communication. Fire alarm and communication

Fire communication and signaling are intended for timely reporting of a fire (notification communication), management of fire departments (dispatching communication) and management of fire extinguishing. For these purposes, telephone and radio communications (manual fire detectors), electric fire alarms (EPS), automatic fire alarms (APS), live communications, beeps, calls, etc. are used.

Rice. 1. Diagram of a manual call point
Manual fire detectors are installed at national economy facilities and in residential premises, in corridors, aisles, and in stairwells. An alarm signal is given by pressing a button. PKIL manual call points (beam fire button detector) are connected to the receiving station. Pressing the K button opens one of the circuits, which leads to the operation and reception of an alarm signal. A current is supplied from the receiving station, which turns on the phone, and the person who raised the alarm receives confirmation that the signal has been received. A handset can be connected to the Mt terminals for negotiations with the attendant.
In industrial buildings with an area of ​​​​more than 500 m2, classified according to fire hazard for categories A, B and C, warehouse and retail premises, exhibition halls, museums, theater and entertainment venues and some others, it is recommended to install electrical fire alarm systems (EPS). EPS are automatic and manual action. In turn, automatic fire alarm systems, depending on the physical factor to which they respond, are divided into thermal (i.e., responsive to temperature increase), smoke, light and combined. In addition, automatic fire detectors are divided into maximum, maximum differential and differential. Sensors of maximum action are triggered when the controlled parameter reaches a predetermined value. Differential sensors respond to a change in the speed of a given parameter, and the most differential sensors react to both.
Fire detectors of all types are characterized by a response threshold - the minimum value to which they respond, inertia - the time from the start of the controlled parameter to the moment it is triggered, and the coverage area - the floor area that is controlled by one sensor.

The principle of operation of thermal fire detectors is to change the physical and mechanical properties of the sensitive elements of these devices under the influence of temperature. A fusible alloy can serve as a sensitive element, as in DTL detectors (thermal fusible sensor); thermocouples, as in DPS detectors (fire alarm sensor) or semiconductor thermistors in POST detectors. Smoke detectors have two main smoke detection methods - photoelectric and radioisotope. A photoelectric smoke detector (IDF) detects smoke by registering light reflected from smoke particles with a photocell. The semiconductor smoke detector (DIP) works on the same principle.
A radioisotope smoke detector (RID) has an ionization chamber with sources of α-particles as a sensitive element. An increase in smoke content reduces the degree of ionization in the chamber, which is recorded.
There are combined detectors (KI) that react to heat and smoke. Light fire detectors register flame radiation against the background of extraneous light sources. Light detector type SI-1 detects a fire by ultraviolet radiation of the flame. The sensitive elements of these detectors are various photodetectors - semiconductor photoresistors, gas-filled photocells with an external photoelectric effect.
Ultrasonic detectors are being used more and more. They have a very high sensitivity and can combine security and fire functions. These devices respond to changes in the characteristics of the ultrasonic field that fills the protected room under the action of the movement of the air that occurs during a fire. The table shows the main characteristics of detectors of various types.

Table 1. Characteristics of various detectors
The main elements of any automatic fire alarm system are: detectors located in the protected premises; a receiving station designed to receive signals from sensors and generate alarms; power devices that provide power to the system electric shock; linear structures - systems of wires connecting detectors with a receiving station.

Rice. 2. Connecting fire detectors to the receiving station:
1 - receiving station; 2 - fire detectors; 3 - power supply
Fire detectors are connected to the receiving station in two ways - in parallel or in series. Parallel switching is used in enterprises with round-the-clock stay of people. Push-button and automatic detectors can be included in the installation branch. A sequential system is installed in large facilities.

One of the conditions for a successful fight against fires is their timely detection, early warning of fire services and the start of active fire fighting at the initial stage of fire development. These tasks are solved with the help of fire communication and alarms. Fire communication provides notification of a fire and a call to fire fighting services, dispatch communication for managing fire extinguishing forces and means, and operational communication of units during fire extinguishing. Fire communication is carried out through a city or special telephone network, or short-wave transceiver systems.

The fire alarm is for early detection ignition and reporting the place of its occurrence and consists of detectors, linear communication and a receiving station.

Fire alarm systems can be either automatic or manual. Depending on the way the detectors are connected by wires to the receiving station, the fire alarm system can be a beam (radial) or loop (ring) system.

Electrical fire alarm detectors are devices that respond to smoke, radiant energy, heat, ionization, the signal of which is transmitted to a receiving station, as well as to the inclusion of stationary fire extinguishing installations.

Activation of detectors, depending on their types, can occur automatically or when manually turned on,

Manual type detectors have a simple contact device and are activated by pressing the start button. Manual call points of the PKIL-7 type of push-button action are located in conspicuous places in buildings and production shops. To signal a fire, break the glass and press the detector button with your hand.

Automatic detectors convert non-electric quantities into an electrical signal. According to the principle of operation, the converters are divided into parametric, in which non-electric quantities are converted into electrical ones using an auxiliary current source, and generator ones, in which a change in a non-electric quantity causes the appearance of its own electromotive force.

Depending on what phenomenon automatic detectors (sensors) react to, they are divided into the following types:

1) thermal fire detectors that respond to temperature rise;

2) sensors that respond to smoke or combustion gases;

3) sensors that respond to light radiation (flame, spark);

4) combined sensors, which use several types of sensing elements based on different conversion principles.

Automatic fire detectors, in turn, are divided into three groups:

a) sensors of maximum action, triggered when the controlled parameters (smoke, temperature, radiation) reach a certain value;

b) differential detectors respond to the rate of change of the monitored parameter;

c) maximum-differential - react both to the absolute value of the controlled parameter, and to the rate of its change.

Thermal sensors of maximum action (such as ATIM, ATP) are triggered when the temperature is reached environment- 50, 70.100, 140°C. As a sensitive element, they use fusible or combustible (celluloid) inserts, mercury, liquid or bimetallic links, as well as electrical devices operating on the principle of changing the electrical conductivity of circuit sections.

The fusible heat sensor DTL (Fig. 16.18) has become widespread due to the simplicity of design and the ability to connect to installations security and fire alarm. The sensitive element of the sensor is formed by two springy plates 2, soldered at one end with Wood's alloy 1 (tin+cadmium+bismuth+lead), with a melting point of 72°C. The second ends of the plates are fixed on a plastic base 3 and connected with an electric clamp 4. When the temperature rises, the junction melts and the plates diverge, breaking the alarm circuit.

Thermal detectors of the TRV type of maximum action (Fig. 16.19) have an explosive design and are installed in explosive rooms of all classes. The principle of operation is based on the difference in linear elongations during heating of a brass tube and an invar rod. These detectors are used not only to signal a rise in temperature above the permissible level (the threshold of operation of various modifications of the expansion valve is 70 and 120 ° C), but also to start automatic systems firefighting.

Differential detectors respond to the rate of temperature rise, regardless of the temperature in the protected area. For example, the DPS-038 fire alarm sensor has a battery of 50 thermocouples as a sensitive element and operates on the principle of the difference in thermoelectromotive force on blackened and silver-plated thermocouple junctions. The detector is triggered by a rapid rise in temperature (at least 30° in 7 s). The estimated service area of ​​the premises is up to 30 m 2 .

Thermal detectors, as a rule, are inertial, i.e. they need some time to operate (from 50 to 120 s.). Often a fire is preceded by smoldering. The initial phase of a fire can last several hours. In this case, the fire alarm system, the action of which is determined by an increase in temperature or the presence of open fire, can signal a fire only after it, having reached the highest phase of development, will spread rapidly. Therefore, in fire alarm systems, detectors are often used that react to the appearance of smoke or gaseous combustion products. The sensitive element of such low-response detectors are photocells, photon counters or ionization chambers.

The principle of operation of smoke detectors is based on a change in the optical properties of the medium when smoke appears and can be carried out in two ways: I) by weakening the primary luminous flux; 2) according to the intensity of the light flux reflected (scattered) by smoke particles.

The first method is used in linear optical-electronic security and fire detectors, the second - in detectors of the IDF and DIP types.

The photoelectric smoke detector IDF consists of an optical assembly containing a light source and a photodetector, and a semiconductor amplifier (Fig. 16.20).

In standby mode, light does not reach the photoresistor, and when smoke appears, light is scattered and the resistance of the photoresistor decreases, which leads to the operation of the amplifier and the issuance of an alarm.

A similar principle is used in DIP-1 and DIP-2 detectors. To ensure resistance to background illumination, they use the method of modulating the light source with pulses from a multivibrator. The detector is triggered only when the smoke particles reflect light from a modulated source. An extraneous light source cannot cause false triggering of the detector.

Similar information.

Not everyone pays attention to small appliances that are hidden on the ceilings of the premises. This is natural, because, seeing something everywhere and everywhere, the brain simply ceases to perceive this something as an unusual phenomenon. And besides, we must also take into account the fact that any such devices are made with the expectation of maximum mimicry with the surface on which they are fixed. Such a complex explanation was required by an ordinary fire alarm, the importance of which should not be underestimated.

Fire detector design

Even if you paid attention to various sensors, this still does not mean anything. The fact is that such traps are just a control system, so to speak, external sense organs that serve the entire system.

They can react to a wide variety of stimuli, and therefore, if we discuss the types of fire alarms, it is impossible not to touch on such a topic.

The detector, which is the very one that is proudly called the alarm, consists of many parts, where the sensors are only outer part designs. So, for example, in addition to traps that respond to various fire factors (smoke, temperature, open fire, etc.), it can also be a whole signal recognition system, with other components, as well as an automatic extinguishing mechanism, etc.

Views and connections

The classification of such devices is quite wide. This is mainly due to the fact that they are used everywhere. It is reasonable that different types are used for each class of premises.

However, it is quite difficult to list the main types of fire communication and alarm systems, simply because these mechanisms are classified very differently. The device is quite complex, and there are also a lot of technical solutions, and therefore we will go through the main types.

Transmitted signal type

Actually, the system for transmitting a signal from an alarm to other elements is a mandatory part of the design, regardless of type. Indeed, if the sensor detects a fire, but the signal does not arrive, there is no point in such a device at all. But the mechanism of action can be of four main types:

• Single-mode, which only signals a fire as such. That is, the sensors turn on only if there are the necessary conditions. But these types of fire alarms are no longer used.
• The most common are dual-mode. The point here is that when the traps do not detect a dangerous situation, they transmit a signal that everything is in order. This means that the system is functioning normally. If the signal does not pass, then the sensor is broken and must be replaced.
• Multi-mode models are "sharpened" specifically for large buildings. After all, the inspector will not walk along kilometer-long corridors just to check why the trap is not transmitting. Such a system is the main view in the school. The security requirements there are high, and they can only be ensured in this way.
• Analog - the most advanced. They react not to a critical, but to any change in the monitored indicators.

signal transmission

This characteristic can also distinguish the types of fire alarms from each other. The transfer can be:

• wired, using cables;
• wireless, where they use a radio signal, or even just a Wi-Fi network.

• Thresholding models only start transmitting when temperature, smoke, or some other characteristic exceeds the threshold;
• Differential detectors emphasize every change in parameters. So you will be notified whenever the value goes up or down;
• Combined systems work by identifying breaking changes, but keeping track of all the others at the same time.

Number of sensors - localization rules

Salt lies in the fact that for rooms of different sizes, the types of fire alarms will be different.

According to this parameter, all fire detectors will be classified as follows:

• Point models are one sensor that most often mounts directly to the detector for space saving and ease of use. Just such functionality you can see in almost every apartment.
• Multi-point models are many sensors that hide in one specific place. That is, if point devices respond to any one specific parameter, then these devices can track their whole galaxy at once.
• Linear, in turn, are interesting in that they track a number of devices. That is, an arbitrary line is drawn from the detector, along which, for example, emitters and photocells are placed. The latter allows you to monitor the level of smoke in the room. Such systems, as in the above example, are called paired, but they can also be single.

Type of sensors

The classification of traps is just the factor by which the signaling working area is determined. Despite the importance of the previous points, the choice is most often made on the basis of the quality of the sensors. There is no escape from this.

For example, the type and type of fire alarm in a school can be very different. But what kind of traps will be installed is determined by the law on fire safety of institutions.

Heat traps

This is the oldest type, since they were used one hundred and fifty to two hundred years ago. Today, their design is a conventional thermocouple, which, in turn, begins to work, that is, conduct current, only when certain temperature air. These types of fire alarms, photos of which are available in the article presented to the readers, can be seen in any building of the last century.

The problem here is pretty obvious - the temperature of the air only rises when the fire is lit.

That is, there is a problem with the speed of response. The last century was the heyday of such sensors, they were installed everywhere. At the same time, they are gradually being replaced by other species.

smoke eliminators

If we talk about such specific things as views, it would be blasphemy not to mention smoke detectors. After all, it is they who today occupy a leading position in this special market in every sense.

Smoke is one of the main signs of a fire. Interestingly, he appears first in most cases. It is often even possible to observe smoke for quite a long time until a flame appears - for example, when wiring is smoldering. So, the advantages over the previous type are obvious. The fire is monitored even at the embryonic stage, and therefore it allows you to take preventive measures.

Everything works on the transparency of the air, but smoke can be determined according to different principles. Linear models use a directional beam of different ranges in their work - a reflective or photocell is also required for operation, which will respond to the beam hit.

When there is no reaction, it means that the transparency is broken, the sensor will work.

If the first type uses the optical and ultraviolet wavelengths, then the second, point, work is based on infrared radiation.

Such waves simply should not return to the trap in normal conditions. If the signal is reflected back, this means the presence of foreign substances in the air.

Point sensors cost less than linear ones, but the latter are, accordingly, more reliable. So you still have to choose.

Flame sensors

This view is common for industrial premises, workshops, etc. That is, you can only work with a flame, since the air is dusty, and the temperature is a priori increased.

They can be infrared or ultraviolet - these are the two main types.

Thus, the device reacts to the heat generated, but immediately, and not when it heats the air, as it works with thermal traps. You can also use electromagnetic sensors - they will respond precisely to this component of the flame, thus avoiding false alarms.

Signaling

A fire can also be tracked through the usual ultrasonic security system of the apartment.

The bottom line here is on what principle the device works. In this case, this is the movement of air masses.

The alarm will respond not only to the intruder, who moves the air while moving, but also to an open flame. The latter will certainly raise a whole layer of heated air up, which will cause the device to operate.

However, relying on such a system is not worth it, since it is not designed to track fires.

Rapid detection and signaling of a fire, timely call of fire departments and fire warning of people in the zone of possible danger, allows you to quickly localize fires, carry out evacuation and take the necessary measures to extinguish the fire. Therefore, enterprises should be provided with communication facilities and fire alarm and warning systems.

To transmit a message about a fire at any time of the day, you can use special and general-purpose telephones, radio communications, and centralized fire alarm installations. Fire warning systems should ensure, in accordance with the developed evacuation plans, the transmission of warning signals simultaneously throughout the house (structure), and, if necessary, sequentially or selectively in its individual parts (section floors). The number of detectors (speakers), their placement and power must provide the necessary audibility in all places where people stay. For the transmission of alert texts and evacuation control, it is allowed to use internal radio broadcasting networks. The room from which the fire alarm system is controlled should be located on the lower floors of buildings, at the entrance to stairwells, in places with round-the-clock stay of staff on duty.

The fastest and most reliable means of detecting signs of fire and signaling a fire is considered to be an automatic fire alarm installation (AUPS), which must work around the clock. Depending on the connection scheme, radial (radial) and ring AUPS are distinguished (Fig. 4.37). The principle of operation of the AUPS is as follows: when at least one of the detectors is triggered, a "Fire" signal is sent to the control panel.

Rice. 4.37. Schemes of radial (a) and ring (b) connections in AUPS: 1 - detectors; 2 - receiving and control device; 3 - power supply from the mains; 4 - emergency power supply unit; 5 - power switching system; 6 - connecting wires

Addressable fire detectors are included only in radial networks; in this case, the place of ignition is determined by the number of the loop (beam) that issued the "Fire" signal. Addressed fire detectors are included in networks of both radial and ring types; the ignition address is determined by the installation location of the detector that issued the "Fire" signal, according to its address number.

At fire and explosion hazardous facilities, AUPS, in addition to signaling a fire, can issue commands to the control circuits of automatic fire extinguishing, smoke removal, fire warning, ventilation, technological and electrical equipment of the facility.

AUPS according to the method of transmitting messages (notifications) about a fire are divided into autonomous and centralized. In autonomous AUPS installations, the "Fire" alarm signal from the detector is sent to the control panel, which is installed in a room with round-the-clock stay of duty personnel. Another calls to the reception post fire brigade and transmits information. In centralized AUPS, fire alerts from control panels are transmitted via a communication channel (for example, a pager communication channel or a radio channel) to a centralized fire monitoring console.

Manual fire detector

One of the main elements of the AUPS is fire detectors - devices that generate a fire signal. There are manual and automatic fire detectors. The manual fire detector (Fig. 4.38, a) turns on the person who discovered the fire by pressing the start button. They can be used to signal a fire from the premises of the enterprise. Inside the building, manual call points are installed as additional technical means of automatic AUPS.

Rice. 4.38. Fire detectors: a - manual IR-P; b - thermal IP-105; c - smoke IPD-1; g - flame detector IP

Automatic fire detectors

They work without human intervention, from the impact on them of factors that accompany a fire: an increase in temperature, the appearance of smoke or flame.

Thermal fire detectors

According to the principle of operation, they are divided into: maximum (IT-B, IT2-B, IP-105, SPTM-70), which are triggered when Pirogovo reaches the air temperature at the place of their installation; differential (Hb 871-20), which respond to the rate of increase of the temperature gradient; maximum differential (IT1-MGB, V-601), which are triggered by one or another prevailing temperature change.

The principles of operation and design of thermal fire detectors can be different: using fusible materials that are destroyed as a result of exposure to elevated temperatures; using thermoelectromotive force; using the dependence of the electrical resistance of elements on temperature; using temperature deformations of materials; using the dependence of magnetic induction on temperature, etc.

The fire detector IP-105 (see Fig. 4.38, b) is a magnetic contact device with a contact output. It works on the principle of changing magnetic induction under the action of high temperature. As the air temperature rises, the magnetic field decreases, and when the threshold temperature is reached, the contact located in the sealed chamber opens. In this case, a "Fire" signal is sent to the control panel.

Smoke detectors

Smoke is detected by a photoelectric (optical) or radioisotope method. The principle of operation of the optical fire smoke detector IPD-1 (see Fig. 4.38, c) is based on the registration of scattered light (Tyndall effect). An infrared emitter and receiver located in an optical chamber in such a way that the rays from the emitter cannot reach the receiver directly. In the event of a fire, smoke enters the optical chamber of the detector. Light from the emitter is scattered by smoke particles (Fig. 4.39) and enters the receiver. As a result, a "Fire" signal is generated and fed to the control panel. In a radioisotope smoke detector, the sensitive element is an ionization chamber with a source of a-radiation (Fig. 4.40). The smoke that is generated during a fire reduces the degree of ionization in the chamber and is registered by the detector.

Rice. 4.39. Scattering of the light flux by particles smoke: 1 - source 2 - smoky environment; 3 - smoke particles

Rice. 4.40. Ionization light chamber (emitter) of a radioisotope smoke detector: 1 - anode; 2 - cathode

Flame fire detectors

(IP, IP-P, IP-PB) allow you to quickly identify the source of an open flame. The sensitive photocell of the detector registers the radiation of the flame in the ultraviolet or infrared parts of the spectrum. Combined detectors IPK-1, IPK-2, IPK-3 immediately control two factors that accompany a fire: smoke and temperature.

Fire detectors are characterized by: response threshold - the lowest value of the parameter to which they respond; inertia - the time from the beginning of the factor, is controlled until the moment of operation; protected area - floor area controlled by one detector. In table. 4.13 are given comparative characteristics detectors of various types.

Table 4.13.

Separate detectors (sensors) of the security alarm (for example, ultrasonic, opto-electric) have high sensitivity and are able to detect the first signs of fire very quickly (rather fire detectors). Therefore, they can combine security and fire functions. However, such detectors can only be additional elements of the AUPS, which enhance fire safety protected object. After all security alarm operates after hours, and the fire department operates around the clock.

When choosing the type and execution of an automatic fire detector, it is necessary to take into account the purpose of the protected room, the fire characteristics of the materials it contains, the primary signs of fire and operating conditions in accordance with DBN V.2.5-13-98.

For right choice automatic fire detectors, it is necessary to take into account the features of the destination object of the protected premises, the degree of their fire hazard, the specifics of the technological process, the fire characteristics of the materials in the room, the primary signs of a fire and the nature of its possible development. It is also necessary to take into account the presence of systems automatic fire extinguishing and other features of the object.

The type and design of fire detectors must be selected taking into account the environmental conditions in the protected premises and the class of the explosive or fire hazardous zone.

The number and location of fire detectors depends on the size, shape, working conditions and purpose of the room, the structure of the ceiling (covering) and the height of the ceiling, the presence and type of ventilation, the workload of the room with materials and equipment, as well as on the type and type of fire detectors and in each case determined design organization, which received a license for this type of activity in the prescribed manner.

Fire detectors are installed, as a rule, under the coating (overlap). In some cases, they may be located on walls, beams, columns, as well as suspended on cables, provided they are at a distance of no more than 0.3 m from the level of the coating (ceiling) and no more than 0.6 m from the ventilation holes.

In rooms with an equal ceiling, point fire detectors are usually located evenly over the area of ​​\u200b\u200bthe ceiling, taking into account the size of the room, as well as the technical parameters of the detectors. Point fire detectors are recommended to be installed according to triangular or square layouts (Fig. 4.41).

Rice. 4.41.

a - the distance between the detectors, b - the distance from the wall to the detector

In some cases, detectors are placed in areas of probable fire, on the paths of convective air flows, and also near fire hazardous equipment.

The distance between the detectors is taken into account the area controlled by one detector. The latter essentially depends on the height of the protected premises. Therefore, the greater the height of the protected room, the smaller the area controlled by the detector. The distance from the detector to the wall, as a rule, is taken to be two times less than the distance between the detectors.

As the practice of operating fire detectors has shown, thermal fire detectors should be used in rooms of low and medium height and relatively small volume. With a room height of 7-9 m, the use of heat detectors is impractical due to the inefficiency of registering a fire.

The threshold temperature for the operation of maximum and maximum differential heat detectors must be at least 20 ° C and not more than 70 ° C higher than the maximum allowable temperature in the room.

Differential heat detectors are effective in rooms where, under normal operating conditions, there is no sudden increase in ambient temperature. Such detectors should not be installed near heat sources that could cause false alarms.

Smoke detectors are installed in rooms where a fire is possible accompanied by a significant release of smoke. When placing them, it is necessary to take into account the paths and speeds of air flows from ventilation systems.

Flame detectors are installed in rooms where there is a possibility of fire with an open flame. It is necessary to avoid various production influences (working welders or other sources of ultraviolet or infrared radiation). Flame detectors must be protected from direct sunlight and direct influence of sources artificial lighting. When locating flame detectors, they must be taken into account. specifications: angle of view, area protected by the detector, maximum fire detection range (distance from the detector to the point "seen" by it).

It should be noted that when choosing and placing automatic fire detectors, it is necessary to be guided by the requirements and recommendations of DBN V.2.5-13-98.

Systems automatic detection and extinguishing fire fighting include:

• automatic fire alarm installations (AUPS) designed to detect a fire in its initial stage, report the place of its occurrence, give an appropriate signal to the security post (duty post);
• automatic fire extinguishing installations (LUP), designed to automatically detect and extinguish a fire in its initial stage with the simultaneous filing of a fire alarm.

The existing practice of designing LUP and AUPS is such that APs simultaneously perform the functions of AUPS. AUPS and AUPS systems protect buildings, premises in which flammable and combustible substances are stored or used, valuable equipment and raw materials, warehouses for petroleum products, varnishes, paints, book depositories, museums, premises with electronic computer technology and etc.

Sensors that respond to fire factors (fire, smoke, gas, fever air, an increased rate of rise of any factor, etc.) in the AUP and AUPS systems are fire detectors (PI), which are installed in the premises to be protected. In the event of a fire, they send a signal to the fire control panel, control devices, as well as to the fire brigade station (or to the post of duty personnel), where they inform about the situation that has arisen, indicating the room, zone where the PI worked.

When two or more PIs are triggered simultaneously (and they are usually placed in each room at least two), the control devices, depending on the program embedded in them: turn on the warning system and control the evacuation of people in case of fire, turn off the power supply technological equipment, turn on smoke exhaust systems, close the doors of the room where the fire that has arisen is supposed to be extinguished with gas fired extinguishing agents, and at the same time delay the release of fire extinguishers for the time during which people must leave the corresponding room; if necessary, turn off ventilation; in the event of a power failure, the system is transferred to a backup power source, a command is given to release the fire extinguishing agent into the combustion zone, etc.

The choice of one or another type of PI depends on the predominant type of emerging fire factors (smoke, flame, etc.). For example, in accordance with "SP 5.13130.2009. Fire protection systems. Automatic fire alarm and fire extinguishing installations. Design norms and rules", approved by order of the Ministry of Emergency Situations of Russia dated March 25, 2009 No. 175, industrial buildings with the presence of wood, synthetic resins or fibers, polymeric materials, textiles, rubber products, protect PI with smoke, heat, flame; rooms with computers, radio equipment, administrative and public buildings - smoke PI, etc.

On fig. 34.1 shows one of the schemes for automatic detection and extinguishing of a fire. In the event of a fire in one of the premises, after the operation of two or more fire alarm sensors 2, the signal from them is fed to the control panel 1. This device sends a signal to the fire department (to the fire department), turns on the light alarms 14 "Fire" located outside and inside the building, and the pump 6 water fire extinguishing or undermines squibs 8 start-up of the gas fire extinguishing system. In addition, the AWP program can provide for the simultaneous de-energization of process equipment through a disconnecting unit 10, turning on light alarms 12 "Do not enter", installed outside the building, and light annunciators 13 "Go away" installed indoors.

In some cases, the program may also delay the release of gas until all doors are completely closed, when a high fire extinguishing concentration is needed. At the same time, the doors close automatically, and their position is controlled by sensors. 4. If necessary, the fire alarm and extinguishing system can be turned on manually by pressing one of the buttons 3. In the event of a malfunction in the automation system, a corresponding signal is sent to the fire department post. When the automatic mode is turned off, the alarms light up 11 "Automatic disabled", located in the protected area.

All automatic fire extinguishing installations can be operated manually and automatically. In addition, they simultaneously perform the functions of an automatic fire alarm.

Automatic fire extinguishing installations are subdivided according to their design into: sprinkler, deluge, sprinkler-drencher, modular; according to the type of fire extinguishing agent used - for water (including mist water, drops - up to 100 microns), foam (including those with high-expansion foam), gas (using carbon dioxide, nitrogen, argon, various freons, etc.), powder (modular), aerosol, combined fire extinguishing.

On fig. 34.2 as an example, a diagram of a sprinkler fire installation. It consists of an extensive system of pipes 7 located under the ceiling and filled with water under pressure created by an automatic (auxiliary) water feeder. 4. Sprinklers (sprinklers) are screwed into the pipes every 3–4 m 8, the outlets of which are closed with glass or metal fusible locks. When a fire occurs and the air temperature in the room reaches a certain value (for various sprinklers it is 57, 68, 72, 74 and up to 343 ° C (16 steps in total)) the locks are destroyed and water, sprayed, enters the combustion zone. The nominal operating temperature of sprinklers is usually higher than the maximum permissible operating temperature in the room by about 1.5–1.14 times. Also used sprinkler AUP with forced start. At the same time, the control and signal valve 5 is activated, the main water feeder is turned on. 2 (pump) that draws water from a water source 1 (main tank or fire water main) and a fire alarm sounds.

Rice. 34.1.

СО1, СО2, СО3, СО1 - loops of light annunciators; 30 - loop sound alert; ШС1, ШС2, ШС3 - loops of fire alarm sensors (PI); MANUAL - a loop of manual start buttons; DC – a loop of control of provision of doors; workstation - automated workplace of the operator; 1 - fire alarm control panel; 2 – fire sensors (PI); 3 – fire extinguishing manual start buttons; 4 – door position sensors; 5 - water sprayers; 6 – water pump; 7 – fire extinguishing gas sprayers; 8 – gas start squibs; 9 – block disconnection from the network of process equipment; 10 – sound annunciator about the fire; 11, 12, 13, 14 – light alarms

When protecting unheated buildings, where there is a risk of water freezing, sprinkler installations of the water-air system are used, filled with water only up to control and alarm valves, after which there is in pipelines with sprinklers compressed air. When opening the heads, air first comes out, and then water begins to flow.

Rice. 34.2.

1 - water sources: 2 - the main water feeder; 3 – auxiliary water supply feed pipeline; 4 - auxiliary water feeder; 5 - control and signal valve; 6 - signaling device; 7 - distribution pipelines; 8 - sprinkler sprinkler

Drenchers of deluge installations, unlike sprinklers, do not have fusible locks, and their outlets are constantly open, and the water supply network itself is closed by a group action valve that opens automatically from the signal of fire detectors.

Sprinkler installations irrigate only that part of the room in which the sprinklers opened, and deluge installations irrigate the entire settlement part at once. These installations are used not only to extinguish a fire, but also as water curtains to protect against fire. building structures, equipment, raw materials. The estimated irrigation area with one sprinkler or deluge type water sprinkler is from 6 to 36 m2, depending on their design and the diameter of the through hole.

As a fire extinguishing agent, sprinkler and deluge installations can also use a foaming solution. Mixed sprinkler-drencher systems are also used.

The power supply of fire alarm systems and fire extinguishing installations must be carried out according to reliability category I (according to the PUE). That is, in the event of a power outage, the AUP and AUPS systems should be automatically transferred to backup power. The delay time is no more than the automatic switching time.

SP 5.13130.2009 defines a list of buildings and structures, individual equipment subject to protection by AUP and AUPS (Table 34.7). For example, buildings for public and administrative purposes, premises for accommodating personal computers protect AUPS regardless of their area, industrial premises with the presence of alkali metals when placed in the basement with an area of ​​​​300 m2 or more - AUP, less than 300 m2 - AUPS, spray booths using flammable liquids and GZH - AUP, regardless of the area.

The type of fire extinguishing and alarm installation or a combination of them, the method of extinguishing, the type of fire extinguishing agent is determined by the design organization specifically for each object individually. This organization must have an appropriate license for the right to design such systems, install and maintain. The register of such organizations is maintained by the Ministry of Emergency Situations of Russia. After the commissioning of fire automatics installations, the head of the organization, by his order (instruction), appoints the persons responsible for their operation (usually these are employees of the departments of the chief mechanic, chief power engineer, instrumentation and automation service).

Daily round-the-clock control over the work of the AFS and AFPS is carried out by operational duty personnel (shift service, fire station), who must know the procedure for calling the fire brigade, the name and location of the premises protected by fire automatics (AFS, AUPS), the procedure for maintaining operational documentation and determining the operability of these systems.

performance automatic installations fire alarms are checked by exposing reusable detectors to exemplary (standardized) sources of heat, smoke and radiation (depending on the type of detector).

Table 34.7

List of buildings, structures, premises and equipment subject to protection by AUP and AUPS

PREMISES
Object of protection
	Standard indicator
Warehouse premises
	300 m2 or more	Less than 300 m2
6. Categories A and B for fire and explosion hazard with the circulation of flammable and combustible liquids, liquefied combustible gases, combustible dusts and fibers (except for those specified in clause 11 and rooms located in buildings and structures for processing and storing grain)	300 m2 or more	Less than 300 m2
Industrial premises
8.1. In basement and basement	Regardless of area
8.2. In overground (except for those specified in paragraphs 11-18)	300 m2 or more	Less than 300 m2
9.1. In the basement and basement:
9.1.1. Not having exits directly to the outside	300 m2 or more	Less than 300 m2
9.1.2. With exits directly to the outside	700 m2 or more	Less than 700 m2
9.2. In elevated	1000 m2 or more	Less than 1000 m2
11. Cooking rooms: aluminum powder suspensions, rubber adhesives; based on flammable and combustible liquids: varnishes, paints, adhesives, mastics, impregnating compositions; rooms for painting, polymerization of synthetic rubber, compressor rooms with gas turbine engines, fired oil heaters. Premises with generators driven by liquid fuel engines	Regardless of area
20. Premises of railway transport: electric machine, hardware, repair, bogie and wheel, disassembly and assembly of cars, repair and assembly, electric cars, preparation of cars, diesel, Maintenance rolling stock, container depots, production of switch products, hot processing of tanks, thermal chamber for processing cars for oil bitumen, impregnation sleepers, cylinders, impregnated wood sludge	Regardless of area
public spaces
26. Premises for storing and issuing unique publications, reports, manuscripts and other documentation of special value (including archives of operational departments)	Regardless of area
28. Exhibition halls	1000 m2 or more	Less than 1000 m2
35. Premises for accommodation:
35.1. Electronic computers operating in complex control systems technological processes, the violation of which affects the safety of people	Regardless of area
38. Premises for other administrative and public purposes, including built-in and attached		Regardless of area

EQUIPMENT
Object of protection
	Standard indicator
1. Spray booths with the use of LVZH and GZH	Regardless of the type
2. Drying chambers	Regardless of the type
3. Cyclones (bunkers) for collecting combustible waste	Regardless of the type
4. Oil-filled power transformers and reactors:
	Regardless of power
	200 MBA and above
6. Racks over 5.5 m high for storage of combustible materials and non-combustible materials in combustible packaging	Regardless of area
7. Oil tanks for hardening	3 m3 or more

For installations with single action detectors, the test is carried out by introducing artificial damage (break) performed in the most remote junction or branch box, which has "clamp" mounting terminals, or by disconnecting the most distant detector from the loop line.

Checking the performance of automatic fire extinguishing installations is carried out by visual inspection of instrumentation and assessing the health of individual components or checking the performance of the installation as a whole, which is carried out according to a specially developed program agreed with the State Fire Supervision Authority. Inspections are carried out at least once a quarter. Their results are formalized by the relevant act.