Unfortunately, not everyone in our country understands the advantages that addressable analogue systems provide, and some even reduce their advantages to “caring for smokers.” Therefore, let’s also take a look at what addressable analogue systems give us.

It is important not only to detect in time, but also to warn in time

Let me remind you that there are three classes of systems fire alarm: non-addressable, addressable, addressable-analog.

In non-addressable and addressable systems, the “fire decision” is made directly by the detector itself and then transmitted to the control panel.

Analog addressable systems are essentially telemetry systems. The value of the parameter controlled by the detector (temperature, smoke in the room) is transmitted to the control panel. The control panel constantly monitors the status environment in all rooms of the building and, based on this data, makes a decision not only on the generation of a “Fire” signal, but also a “Warning” signal. We especially emphasize that the “decision” is made not by the detector, but by the control panel. The theory states that if you plot the intensity of a fire versus time, it will look like a parabola (Fig. 1). On initial stage During the development of a fire, its intensity is low, then it increases and then an avalanche-like cycle begins. If you throw an unextinguished cigarette butt into a basket of papers, they will first be observed to smolder with the release of smoke, then a flame will appear, it will spread to the furniture and then the intensive development of the fire will begin, which is no longer easy to cope with.

It turns out that if a fire is detected at an early stage, it can be easily extinguished with a glass of water or a regular fire extinguisher and the damage from it will be minimal. This is exactly what analog addressable systems allow you to do. If, for example, a non-addressable (or addressable) heat detector provides the formation of a “Fire” signal at a temperature of 60 ° C, then until this value is reached, the duty officer does not see any information on the control panel about what is happening in the room. Still, this presupposes a significant fire. A similar situation is observed with smoke detectors, where the required level of smoke must be achieved.

Addressable does not mean analog addressable

Addressable analogue systems, constantly monitoring the state of the environment in the room, immediately detect the beginning of a change in temperature or smoke and issue a warning signal to the duty officer. Therefore, analogue addressable systems provide early fire detection. This means that the fire can be easily extinguished with minimal damage to the building.

Let us emphasize that the “watershed” is not between non-addressable systems, on the one hand, and addressable and addressable-analog systems, on the other, but between addressable-analog and other systems.

In real analog addressable devices there is a principle. the ability to individually set not only the levels of formation of the "Fire" and "Warning" signals for each detector, but also to determine the logic of their joint operation. In other words, we get our hands on a tool that allows us to optimally create an early fire detection system for each object, taking into account its individual characteristics, i.e. we have a principle. the ability to optimally build a system fire safety object.

At the same time, a number of important tasks are also solved, for example, monitoring the performance of detectors. Thus, in an addressable analog system, in principle, there cannot be a faulty detector that is not detected by the control panel, since the detector must transmit a certain signal all the time. If we add to this the powerful self-diagnosis of the detectors themselves, automatic dust compensation and detection of dusty smoke detectors, it becomes obvious that these factors only increase the efficiency of analogue addressable systems.

Key Features

An important component of addressable analog devices is the construction of alarm loops. The loop operation protocol is the company's know-how and constitutes a trade secret. At the same time, it is he who largely determines the characteristics of the system. Let's study the most characteristic features of addressable analog systems.

Number of detectors in the loop

Typically it ranges from 99 to 128 and is limited by the energy capabilities of the detectors' power supply. In early models, detectors were addressed using mechanical switches; in later models, there are no switches, and the address is stored in the non-volatile memory of the sensor.

Ring alarm loop

In principle, most addressable analog devices are capable of working with radial train. but there is a possibility of "losing" a large number of detectors due to a broken cable. Therefore, the ring loop is a means of increasing the survivability of the system. If it breaks, the device generates a corresponding notification, but ensures operation with each half-ring, thereby maintaining the functionality of all detectors.

Localization devices short circuits

This is also a means of increasing the “survivability” of the system. Typically, these devices are installed through 20–30 detectors. When there is a short circuit in the loop, the current in it increases, which is detected by two localization devices, and the faulty section is switched off. Only a segment of the loop with two short-circuit localization devices fails, and the rest of it remains operational due to the ring organization of the connection.

In modern systems, each detector or module is equipped with a built-in short-circuit localization device. At the same time, due to a significant reduction in prices for electronic components, the cost of sensors has not actually increased. Such systems practically do not suffer from short circuits of loops.

Standard set of detectors

It includes smoke optoelectronic, thermal maximum temperature, thermal maximum differential, combined (smoke plus thermal) and manual call points. These detectors are usually sufficient to protect the main areas of the building. Some manufacturers additionally offer sufficient exotic species sensors, for example, analog addressable linear detector, optical smoke detector for rooms with high level pollution, optical smoke detector for explosive areas, etc. All this expands the scope of application of analogue addressable systems.

Non-addressable sub-loop control modules

They allow the use of non-addressable detectors. This reduces the cost of the system, but at the same time, naturally, the properties inherent in addressable analog equipment are lost. In some cases, such modules can be successfully used to connect conventional linear smoke detectors or create explosion-proof loops.

Control and monitoring modules

They are included directly in alarm loops. Typically, the number of modules corresponds to the number of detectors in the loop, and their address field is additional and does not overlap with the addresses of the detectors. In some systems, the address field of detectors and modules is common.

The total number of connected modules can be several hundred. It is this property that allows, on the basis of the addressable analogue fire alarm system SPS, to integrate automatic fire protection buildings (Fig. 2).

During integration, actuators are controlled and their operation is monitored. The number of monitoring and control points is precisely several hundred.

Branched logic for generating control signals

This is an indispensable attribute of analogue addressable control and control devices. It is the powerful logical functions that ensure the construction of a unified automatic fire protection system for the building. These functions include the logic for generating a “Fire” signal (for example, for two triggered detectors in a group), and the logic for turning on the control module (for example, for each “Fire” signal in the system or for a “Fire” signal in a given group), and the principle . the ability to set time parameters (for example, when there is a “Fire” signal, turn on the control module M after time T1 for time T2). All this allows you to effectively build on the basis of standard elements, even powerful complexes gas fire extinguishing.

And not just early detection

The very principle of constructing addressable analog systems allows, in addition to early fire detection, to obtain a number of unique qualities, for example, increasing the noise immunity of the system. Let's explain this with an example.

In Fig. Figure 3 shows several consecutive polling cycles (n) by a thermal device addressable analogue detector. For ease of understanding, on the ordinate axis we will plot not the duration of the signal from the detector, but the temperature value immediately corresponding to it. Suppose that during polling cycle 4 there was a false signal from the detector or a distortion in the duration of the detector response under the influence of electromagnetic interference, that the value perceived by the device corresponds to a temperature of 80 °C. If a false signal arrives, the device must generate a “Fire” signal, i.e. false alarms will occur.

In analog addressable systems, this can be avoided by introducing an averaging algorithm. For example, let's introduce averaging over three consecutive samples. the value of the parameter for “making a decision” about a fire will be the sum of the values ​​for three cycles, divided by 3:

• for cycles 1, 2, 3 T=60:3=20 °C – below the threshold;
• for cycles 2, 3, 4 T=120:3=40 °C – below the threshold;
• for cycles 3, 4, 5 T=120:3=40 °C – below the threshold.

That is, when a false count arrives, the “Fire” signal is not generated. At the same time, I would like to draw special attention to the fact that since the “decision” is made by the control panel, no resets or re-requests of the detectors are needed.

Note that if the received signal is not false, it means that in cycles 4 and 5 the parameter value corresponds to 80 °C, then with this averaging the signal will be generated, since T = 180:3 = 60 °C, which means it corresponds to the threshold for generating the "Fire" signal ".

What's the result?

So, we are convinced that thanks to our unique properties addressable analogue systems are effective means ensuring fire safety of facilities. The number of detectors in such systems can be several tens of thousands, which is enough for the most ambitious projects.

The market for analogue addressable systems abroad has shown a steady upward trend over the past few years. The share of addressable analogue systems in the total production volume confidently exceeded 60%. The mass production of addressable analogue detectors led to a reduction in their cost, which was an additional incentive to expand the market.

Unfortunately, our share of addressable analogue systems amounts to various estimates from 5 to 10%. The lack of an insurance system and current regulations do not contribute to the introduction of high-quality equipment and the cheapest equipment is often used. Nevertheless, certain shifts have already emerged, and it seems that we are on the verge of a fundamental change in the market. Totally agree last years the cost of optical smoke detectors and analogue detectors in Russia has decreased by approximately 2 times, which makes them more affordable. Without addressable analogue systems, it is unthinkable to ensure the security of high-rise buildings, multifunctional complexes and a number of other categories of objects.

Smoke protection systems for buildings: design problems
It’s too early to write off

FOTObank
Infrared linear smoke detector consisting of an emitter and receiver SYSTEM SENSOR
Laser linear smoke detector with receiver and transmitter - in one housing - and reflector Optical detectors open flame"Pulsar" from KB "PRIBOR" with a sensor built into the control device with remote sensor
Non-addressable point smoke detectors of domestic production: (IP 212-3SU, DIP 54-T, DIP 3-M3)
Domestic thermal addressless detectors (MAK-1, IP 101-1A, IP 103-31)
SYSTEM SENSOR
Point smoke detector "Profi" series 150 years ago, the tower was the most effective means of detecting fire
SYSTEM SENSOR
Combined smoke-heat detectors - addressable
SYSTEM SENSOR
intellectual
SYSTEM SENSOR
addressless
SYSTEM SENSOR
Thermal maximum differential addressless detector of the "Eco" series
Addressless manual call points with “button” and rotary knob
SYSTEM SENSOR
Addressable analog manual call point "Eco" series
Addressless smoke and thermal maximum detectors from APOLLO
SYSTEM SENSOR
Addressable analogue detectors - point smoke;
SYSTEM SENSOR
maximum differential Domestic autonomous smoke detectors alarm circuit based on autonomous smoke detectors
: (IP 212-50, Agat, IP 212-43M) (Agate)
Addressless fire alarm circuit Remote control for measuring and monitoring the parameters of “smart” sensors
SYSTEM SENSOR
Laser tester for remote testing of smart smoke detectors

In the previous issue of the magazine we talked about primary fire extinguishing agents. But they should be activated only after detecting a fire. What happens if a starting fire is not detected in time? That's right, a big and irreparable disaster will happen. Therefore, today we will talk about modern means of automatic fire detection at the earliest stage of its occurrence - fire alarm systems

Who should detect a fire?

About 150 years ago, the most effective means of detecting a fire was the fire tower - the tallest building in the city. With warning means it was even simpler - run out into the street and shout loudly: “Fire!” Everyone who heard it was obliged to run to extinguish it - “some with a hook, some with a bucket.”

Naturally, these means are a thing of the past. In order to detect a fire at its earliest stage, when it is called a fire, they are now used modern systems detection and fire alarm systems (FAS). They are designed for round-the-clock monitoring of a protected facility and alerting the owner about the first signs of fire or smoke. To create such systems, the following are used: detection devices - fire sensors (it would be more correct to call them detectors), signal processing devices (reception and control devices - PKP) and executive equipment (warning equipment). They are produced by such companies as ESSER (Austria), Texecom and PYRONIX (Great Britain), System Sensor (Italy), Securiton (Switzerland), ESMI (Finland), Napco (USA), ADEMCO - a division of Honeywell (USA), as well as domestic "RUBEZH" (Saratov), ​​"IVS-Signalspetsavtomatika" (Obninsk), NVP "BOLID" (Korolev), "ARGUS-SPECTR" and "IRSET-CENTER" (St. Petersburg), “Siberian Arsenal” (Novosibirsk), “Radiy” (Kasli), etc.

Fire detectors

They are the main elements of fire detection systems. First of all, the efficiency of the system depends on their sensitivity and noise immunity. In private housing, smoke, heat detectors and open flame detection devices. As a rule, they are all “threshold”, that is, they are triggered if the controlled parameter exceeds the specified value.

Smoke detectors. Smoke is the most characteristic feature fire at its earliest stage. By measuring the concentration of smoke in the air, the sensor “concludes” that there is a fire. Smoke detectors are divided into point and linear.

Spot Measurements are taken at the location where they are installed. In private housing, only photoelectric point detectors are used. A measuring chamber with a light source and a photodetector is hidden inside such a device. Smoke particles entering the chamber change the light transmission of the air and scatter the light flux. These changes are captured by the photodetector. But in different designs differently. In some, it records the general weakening of the light flux (if it is located strictly opposite the light source). In others - flux scattering (the photodetector is located at right angles to the light source). The first of the devices described are more sensitive, but less resistant to interference (for example, dust) and require frequent maintenance. The latter are slightly less sensitive, but more resistant to noise. They are mainly used when creating SPS in private housing. They are usually mounted under the ceiling, since hot gases and smoke rise upward. The area controlled by one smoke detector can be up to 80 m2. Even if the footage of the room in which the sensor is installed is much smaller than this value, to increase the reliability of fire detection, at least two fire detectors should be installed in it. When using suspended ceilings and laying power wiring behind them, it is necessary to protect the ceiling space with separate smoke detectors.

Let's discuss these issues using the example of point smoke detectors. The sensitivity of sensors can be high, medium and low, but must necessarily be in the range from 0.05 to 0.2 dB/m (it is in such units, converted using a rather complicated formula into volume percentages, that it is customary to measure sensitivity - a standard smoke sensor should operate if smoke at the place of its installation causes the light to weaken at a distance of 1 m by 1.1-4.5%). Some detectors have the ability to adjust sensitivity, which is done with a special switch installed on the back wall. It can be either two-position (switches from the upper limit directly to the lower limit) or three-position (switches from the upper limit to the lower through the middle, for example, in the “Profi” and Leonardo series from SYSTEM SENSOR). It is better to choose a detector with a three-position regulator. Why? Configured to the upper limit of sensitivity, the device reacts to the minimum smoke content in the air and can “trigger” not only when smoking in the room, but also when frying meat or operating a toaster in the kitchen (practically these are the same “false alarms”). The minimum sensitivity may not be enough - it seems to you that the sensor should work, but it stubbornly remains silent. Most likely you will be satisfied average level sensitivity. And a sensor with a two-position regulator lacks just that. Sensors of any type require periodic care, or rather, maintenance. Why is it necessary? It is clear that fumes and dust will settle on devices located under the ceiling. Moreover, these “delights” settle not only on the housings, but also inside the measuring chamber, weakening the luminous flux to which the device is configured and causing a so-called false positive. The sensor reacts to unsettled (floating in the air inside the chamber) dust particles in the same way as to smoke. A “false alarm” is a rather unpleasant phenomenon for owners: nothing burns, but the sensor persistently signals: “FIRE!” At the same time, the owners get nervous and rack their brains: “What if something is really burning in the house, but we don’t notice?! We should check everything again!” To prevent dust from getting inside the measuring chamber, manufacturers enclose it with a rather complex, almost labyrinthine structure and complicate the geometry of the housing, thereby reducing the likelihood of “false positives.” The settled dust, of course, must be removed periodically. But if it costs nothing to wipe dust from the case, then it can be quite difficult to remove it from the “labyrinth” enclosing the measuring chamber. And if you wipe the optics, even more so, if you overdo it, you can disrupt the alignment (the optics in this case are very miniature). In general, it is better to entrust care to specialists who will periodically come to your home.

Linear smoke detectors. consist of two elements that outwardly resemble CCTV cameras - an emitter and a receiver-converter. They are installed opposite each other on opposite walls of the room ("IPDL" from Poliservis, price - $95; "SPEC-2210" from SPEC, price - $230; "6424" from System Sensor, price $540). IN Lately models have appeared in which both elements are combined in a common housing - in this case, there is a reflector opposite the emitter (“6200” and “6500” from System Sensor). The emitter can be either infrared or laser, operating in the visible range of red light. The appearance of smoke in the space between the transmitter and receiver (or between the transceiver and reflector) causes a weakening of the received light flux. The magnitude of this attenuation is recorded by the receiver-converter. And if the set threshold is exceeded, it generates a “Fire” signal.

Such sensors are beneficial only for large rooms, since they detect smoke in an area from 10 to 100 m long and from 9 to 18 m wide (that is, they provide control of an area from 90 to 1000-2000 m2). In general, one linear detector is quite capable of replacing a dozen point detectors, which can be beneficial not only economically, but also from the point of view of room design. But there are also disadvantages. The response time of the devices depends on the volume and even the configuration of the room. “False alarms” can be caused by sudden changes in direct and reflected light, lightning flashes, as well as changes in the relative position of parts.

Thermal fire detectors. Sensitive elements of heat detectors can be: bimetallic plates (for example, in “IP-103-5” from “KompleksTroyservis”; “IP 101-1A” from “Siberian Arsenal”), semiconductor thermistors, etc.

Based on their operating principle, heat detectors are divided into passive (contact) and active (electronic). Passive ones do not consume electricity and function as follows: when the temperature in the room reaches critical (about 70 C), the sensitive element either generates a certain signal (due to the thermoelectric effect) or opens/closes the contact electrical circuit, thereby giving an alarm signal. Active devices consume electricity, but they provide information not only about the achievement of a critical temperature in the protected area, but, most importantly, about changes in the rate of temperature increase. They are usually called differential detectors. Inside their body there is not one sensitive element, but two - one is in direct contact with external environment, the other is hidden inside the case. If the temperature during a fire rises quickly, the device records the difference in the readings of the sensitive elements and sends an alarm signal to the control panel ("MAK-DM" from NPP "Spetsinformatika", Moscow, price - 215 rubles; "IP 115 - 1" from " Magneto-Contact", Ryazan, price - 315 rubles; "5451E" from System Sensor). If the temperature rises slowly (then the temperature of the elements changes equally), the device detects that it has exceeded a threshold value and also sends an alarm.

As a result, if passive heat detectors are suitable only for detecting fires with an open flame, accompanied by a sharp excess of the threshold temperature (they are triggered when something is already burning), then differential ones give an alarm when there is no open flame yet, and the temperature has just begun grow, but at an “unacceptable” speed. This explains the fact that passive sensors have recently been used in alarm systems less and less (and this despite their cheapness - 15-20 rubles). Consumers prefer sensors, albeit more expensive, that are triggered at an earlier stage of a fire - differential ones. They are usually used where smoke detectors would give false alarms, for example in kitchens, showers, smoking rooms, etc. For rooms such as boiler rooms, where rapid temperature increases are common, threshold detectors at a temperature of 70 C are more suitable - differential detectors here will give false alarms.

Optical open flame detectors. It is clear that any combustion source is a source of optical radiation in the range from infrared to ultraviolet. Detection of such radiation using a photodetector that has high spectral sensitivity in the ultraviolet or infrared region, but is insensitive to the visible part of the spectrum, is the task of optical open flame detectors.

On sale you can find mainly infrared optical devices (for example, a series of Pulsar sensors from KB Pribor, Yekaterinburg, price - from 1360 to 2200 rubles; Spectron from NPO SPECTRON). The sensor in them can be either built into the receiver-converter or remote. In the latter case, the sensor is installed directly in the controlled area and is connected to a receiver installed outside it via a fiber optic cable (length up to 20 m).

Optical detectors are low-inertia devices with minimal fire detection time. Detection angle - 90-120, range - from 13 to 32 m. They can detect both smoldering fires and open flames. Their disadvantage is that if the fire is obscured by building elements or furniture, the detector will not detect it. Such devices are indispensable where a flame can quickly arise without smoke (garages, storerooms, rooms with electrical appliances). For example, in garages where gasoline and other petroleum products can ignite, at least two such devices should be installed so that the car in the center does not block the flame.

Combined detectors They are a combined device of two sensors in one housing, controlled by one microcircuit. For example, the “IP212/101-2” detector of the “Eco” series from SYSTEM SENSOR (price - 320 rubles) combines the functions of a smoke optical-electronic and thermal maximum differential detector, due to which it is triggered in case of any fire (both accompanied by smoke and and smokeless, but with an increase in temperature). It should be noted that combined detectors of this type have recently become increasingly popular, since they relieve consumers of the need to install two types of sensors in one room - smoke and heat (this need often arises, for example, in garages). Naturally, such a device costs more than a separate smoke or heat device, but cheaper than both combined (smoke "IP212-58" - from 227 rubles, heat "IP101-23" - from 217 rubles).

On the one hand, a combination detector is a good thing because it allows you to detect fires various types- both smoldering and open flame, but smokeless. And in general, the fewer devices are installed, the less they need to be maintained. On the other hand, as is known, the reliability of operation of any combined devices is always lower than that of monofunctional ones. So if you buy a combined sensor, then it should be a highly reliable one from a well-known company.

Manual call points- This " panic buttons", used to signal a fire "manually" (for example, if it is detected before the alarm system sensors are "triggered"). They are installed on evacuation routes (in corridors, passages, on stairwells etc. at a height of 1.5 m from the floor level) at least one for each of the paths, and if necessary - in separate rooms. In multi-storey buildings, manual call points must be on all staircase landings of each floor (NPB 88-2001*). Their installation sites must have artificial lighting.

Autonomous detectors. You can create a basic fire alarm by installing autonomous smoke detectors, for example, one for each room (if they are small). These devices are called autonomous because inside each of them there is an independent power source (Krona, Corundum - 9V battery), which must be changed periodically (about once a year). But the system is absolutely independent of the presence of supply voltage in the network (it is simply not necessary). In addition to the battery, a sensitive element (smoke sensor) and an alarm (siren) are hidden inside the case, emitting a sound with a volume level of 85-120 dB. After the sensor is triggered, the alarm will “scream” until you intervene or the battery runs out. Despite the fact that autonomous detectors are somewhat more expensive than conventional ones ("traditional"), which have neither a power source nor a siren, a fire alarm system based on autonomous sensors has a minimal cost, since it does not have wires, control panels and the necessary operation of the backup power system. The only type of maintenance that autonomous detectors require is periodic dust blowing. The disadvantage is that each sensor is triggered on its own and if you are at the far end of the house, you may not hear the alarm.

Until recently, only foreign-made autonomous detectors were available for sale: from Dicon, BRK (both in the USA) - $20-25, as well as several Chinese models - about $15 each. Currently, their serial production has also been mastered by the domestic industry: " IP212-50M" from "RUBEZH" (Saratov), ​​price - 420 rubles; "DIP-47" from "Agata" (Obninsk), price 435 rubles, etc. Moreover, according to experts, the quality of these models is not inferior to imported ones and even surpasses them in some ways. For example, the device "IP212-43" ("DIP-43") from "IVS Signalspetsavtomatika" emits not one, but several types of light and sound signals - "Attention", "Fire", "External alarm", which can be used quite objectively assess the situation without yet seeing what happened. In addition, it gives a signal that the battery is low. You can also find autonomous co-produced detectors on sale. For example, the companies "KrilaK" (Ekaterinburg) and Kidde safety (USA) produce an autonomous fire detector "RE-9", the price is $ 18.

More “advanced” models of autonomous devices are also produced, by connecting them with a telephone (copper) wire you can get an alarm system (but without a control panel). The activation of one sensor in it triggers the others. These are, for example, detectors such as "EI 100C" (EI Ltd, Ireland, $ 17), "DIP-43M" ("IVS Signalspetsavtomatika", price - 576 rubles), etc. You are guaranteed to hear the signal of such a system, in no matter what room they are in. That's a plus. The downside is that it is difficult to figure out by ear where exactly the fire occurred. After all, everyone is buzzing at once!

Fire Alarm Systems

Typically, fire alarm systems consist of detectors of the types listed above, as well as a mandatory control panel (device) - control panel, which receives their signals. Experts usually call such systems traditional. Currently, there are three main types of such systems: non-addressable, addressable, and addressable-analog.

Non-addressable systems consist of threshold (smoke, heat, flame) and manual call points, connected to the control panel by a wire (it is also called a line or loop). The sensors do not have their own email address that is reported to the remote control. As a result, when one of them is triggered, neither its number nor the room where it is located is marked on the remote control. Only the number of the loop (line) on which the triggered sensor is installed is recorded. As a result, the owners, in order to understand the situation, must quickly inspect all the premises protected by this line. To make it easier to determine the location of the fire, they try to lay one line into each room. But this path (increasing the number of lines) is not always suitable, since it significantly complicates the wiring diagram and increases the cost of installation work. That is why the use of non-addressable systems is considered appropriate only for small objects (less than 20 premises).

In the simplest address systems Threshold detectors are equipped with a so-called addressable module, which transmits its code via a loop to the control panel in the “FIRE” mode. This code determines the specific location where the signal is generated, which increases the speed of response to it. This, one might say, is the most cheap way transformation of an addressless system into an addressable one (for example, the “S2000-AP1” module from NVP “BOLID”, price $ 10). Another advantage of such a system is that you can run not just one line to each room, but create extended lines, saving wires and the labor of installers. However, a detector equipped with an addressable module cannot control its state and transmit a “FAULT” signal to the control panel, and if the addressable module fails, the control panel generally stops receiving signals from the sensor. Polling address systems they use a different type of control panel, and the communication between the detector and them becomes two-way. The control panel not only receives signals from detectors, but also automatically tests the presence of communication with them and their serviceability (carried out every few seconds). As a result, the reliability of the SPS is significantly increased, and you can always be sure that the sensors are in good working order and will work on time. And it’s easier to use survey-address systems - both for owners and installers. For example, temporary removal of one of the sensors (repair, maintenance) does not cause failure of the entire loop - the control panel simply notes during the next poll that the sensor is missing. In addition, interrogation systems make it possible to create not only a linear, but also a branched structure of loops (with the number of sensors of the order of 100), which in some cases makes it possible to simplify and, therefore, reduce the cost installation work. To work in such systems, detectors can already be offered not only with precise three-position setting of the sensitivity level, but also with automatic compensation for dust in the smoke chamber (for example, Leonardo series sensors from System SENSOR, which the manufacturer calls “smart”).

Change No. 4 dated November 20. 2000 to SNiP 2.08.01-89* “RESIDENTIAL BUILDINGS”

3.21. Apartment and dormitory premises (except for toilets, bathrooms, showers, laundry rooms, saunas) should be equipped with autonomous optical-electronic smoke detectors that meet the requirements of NPB 66-97, with protection category IP 40 (according to GOST 14254-96). Detectors are installed on the ceiling. It is allowed to install on walls and partitions of rooms no lower than 0.3 m from the ceiling and at a distance of at least 0.1 m from the upper edge of the detector's sensitive element from the ceiling.

SNiP 31-02-2001 “RESIDENTIAL HOUSES SINGLE-Apartment”

6.13. Houses with a height of three floors or more must be equipped with autonomous optical-electronic smoke detectors that meet the requirements of NPB - 66 - 97, or other detectors with similar characteristics. At least one fire detector must be installed on each floor of the house. Smoke detectors should not be installed in the kitchen, or in bathrooms, showers, toilets, etc.

“General provisions for technical requirements for the design of residential buildings with a height of more than 75 m”

(developed by the State Unitary Enterprise NIAC Moscow Architecture Committee, approved by the Moscow government). We will not quote this document, but will only say that in buildings with a height of 75 to 100 m, addressable fire alarm systems must be installed, and in buildings with a height of 100 to 150 m - addressable analogue systems, that is, systems that make possible control evacuating residents, for example, with the help of light and sound alarms installed on staircases. An automatic fire extinguishing system must be installed above the entrances to apartments. Apartments must have primary fire extinguishing equipment and fire hydrants in bathrooms, bathrooms, and hallways. In addition to the fire warning system, video surveillance is required in houses (in staircases, to monitor the progress of evacuation).

Addressable analogue system. In it, the detector is not only periodically polled by the control panel, but also in response reports the value of the parameter it controls: temperature, smoke concentration, optical density of the medium, etc. That is, the control panel is here the center for collecting telemetric information. Based on the nature of changes in the monitored parameters reported by different detectors installed in the same room, it is the control panel, and not the detector (as in the case of addressable and addressless systems), that generates a fire signal, which increases the reliability of fire detection. The addressable analog system also has several more advantages compared to the polling address system: The number of loops can be reduced to one - a ring (sometimes called a loop), to which up to 99 can be connected automatic detectors+ 99 manual call points, addressable sirens and modules for controlling ventilation, smoke removal, etc.

Failure of a sensor or a broken wire will not disrupt the operation of the system - it will continue to poll sensors both on one side of the break and on the other, informing those who operate it which sensor has failed or between which sensors there has been a break.

It is the control panels that control the detection lines (loops) with sensors installed in them, provide indication of detected faults and fires, and command the lines of sound and light alarms (if there are any in the system). The control panel is powered from the mains alternating current voltage 220 V, but uses an internal voltage of 12 or 24 V. In case of loss of mains voltage, it is supplied with backup batteries (1 or 2 12 V batteries).

To make it clear how the system functions, let's look at what happens when triggered, for example, smoke detector. In its normal state, it consumes a current of no more than 100 μA. But, having caught smoke, it goes into an alarming state - it turns on the LEDs, thereby increasing the current consumption to 30 mA (this value depends on the design of the remote control). The control panel, having detected increased current consumption, turns on LED fire indicators and activates an audible alarm. The fire detector remains locked in the “alarm” state, even if it no longer senses smoke, which ensures detection of a smoke zone if smoke enters the detector only periodically. The “alarm” signal can be “reset” only from the control panel by removing power from the detection line by pressing a special button. In addressless systems, the loop has its own “reset” button.

For each of the systems (addressless, addressable, addressable analogue) their own control panels are used, which differ in the set of functions they perform. If in non-address systems the devices simply mark the line on which the operation occurred (as in "Signal-20 and - 20P" from NVP "BOLID", price - 2350-2720 rubles; "Granit-24" from "Siberian Arsenal", price - 2800 rubles. ; "PPK-2" from "IVS SIGNALSPETSAVTOMATIKA", etc.), then in address schemes they provide automatic checking of the serviceability of lines and sensors ("Raduga-2A" from "Argus-Spectrum", price - from 6340 rubles), and in addressable analogue systems even detect the location of a line fault (Rainbow-3 from Argus-Spectrum, price from 15,900 rubles, as well as devices from Esser (Essertronic 8000C) and Apollo).

The control panel for each of the listed systems can be divided into devices of small, medium and large “information capacity”. This depends on the number of connected loops, sensors and functions performed. And the most suitable devices are selected for each specific object (house, apartment). What can I recommend? Perhaps it is always better to prefer a device from a large manufacturer (foreign or domestic) that has been on the market for a long time. Which device to choose from the range of a particular manufacturer should be determined by the company installing your alarm system. But here we will allow ourselves some advice.

Firstly, it is better to choose, as they now say, an “intuitive” PCP. That is, so that you understand everything that is displayed on its panel even in a half-asleep state. And so that they can quickly and easily carry out any necessary actions with the device, because there will be no time to read the instructions for operating it during a fire.

Secondly, it is always better to prefer PCP, so to speak, with a small margin. For example, with the ability to connect another loop without changing previously laid lines.

Thirdly, in the event of a fire, a “smart” device should automatically perform a number of necessary actions for you, which the owner may well forget about in the heat of fighting the fire. For example, turn off the supply exhaust ventilation in order to prevent the spread of fire through this system, to cut off power to the main electrical consumers, etc.

Sounders

This concept hides all the actuators that will begin to work at the command of the control panel after a fire is detected. In the simplest case, these are sound, light or light-sound annunciators (in other words, “sirens”, “howlers”, “flashing lights” and “blinkers”). Even not very powerful sirens placed inside your home will warn you in time about impending trouble. More powerful devices located on the walls, roof or attic of a country house will bring the signal about a fire to public attention. It’s just necessary that there be someone who will perceive (see, hear) the fire signal given by the system and quickly respond to it - go to find out what happened, and if a fire actually occurs, put it out or call the fire brigade. And that means this notification option is only suitable for own home in a cottage village with centralized security. And even then it’s a stretch - it’s also not easy for security to immediately figure out in which building the siren is wailing. Neither for an apartment building, nor for a holiday village or gardening community, in which there is no centralized security, this method of notification is completely unsuitable.

In apartment buildings and telephone-connected cottage villages, you can output a signal from home control panels to the security console, and let it take appropriate measures. We just need to work together to equip her post with the appropriate remote control.

How to organize the sending of a fire message from the fire alarm system installed in the house if there is no telephone connection? And for this case, there are a number of devices. For villages where there is security, special radio communication systems are produced. In this case, all houses are equipped with a device that can transmit a pre-recorded voice message, and the security post is equipped with a receiving device for the corresponding number of houses. (In a similar way, the issue of sending messages about incidents when calling private security, if the country house is guarded by it, is resolved. The only difference is in the power of the transmitting device.)

If your own security is in apartment building or the village is absent, but they are within the coverage area of ​​GSM cellular communications, you can use devices that will send an SMS message about the incident. These devices are usually called dialers. They are capable of both connecting to any security and fire alarm system and being used as an independent receiving and control device (determined by design). When an alarm is triggered, the device sends an SMS signal to any (there may be three or more) cell phone numbers specified by the owner (you, relatives, friends, neighbors, etc.).

Perhaps the most common device of this type at present is the GSM-UO-4C (Bolid company, price - about $ 130). The cost of installing a turnkey system based on it costs approximately $400. A significant disadvantage of the system is that it can only operate in a heated room (operating temperature - from +1 to +45 C). Devices similar in principle of operation, but more modern, are offered by companies such as Pyronix (devices of the Matrix series, price - from $30 to $120, "Security Formula" (models of the ForSec-GSM series - from $450), etc.

Cost of fire alarm systems (FAS)

The cheapest are addressless fire alarm systems based on domestically produced equipment (we have already outlined the range of manufacturers). Thus, a point smoke sensor costs from 160 to 400 rubles, a linear smoke sensor - from 2980 to 7180 rubles, a thermal passive - from 11 to 60 rubles, a differential - from 150 to 350 rubles, an optical open flame - from 1350 to 5600 rub. etc. Domestic sensors generally cope well with their task, but, as a rule, they are somewhat inferior to their imported counterparts in reliability and aesthetics.

Fire alarm systems at an average price level are usually created on the basis of sensors and control devices from such well-known foreign companies as ADEMCO, System Sensor, Napco, Texecom, PYRONIX. So, a point smoke sensor in this price category will cost $15-30, a linear smoke sensor - $100-500, a differential one - $10-20, etc.

Expensive ATP systems include address systems. Most often, they are built on specialized control panels and sensors from ESSER, ESMI, Honeywell, Securiton, etc. In this category, a point smoke sensor costs from $30 to $100, a linear smoke sensor - from $500 to $1000, a differential one - from $30 to $1000 60, optical open flame - from $200 to $500.

Despite the fact that addressless detectors are the cheapest, installing a complex SPS based on them can be quite expensive. Addressable detectors cost at least 50% more than non-addressable ones, but installing an SPS based on them can be cheaper. Thus, according to a number of companies we surveyed, for a building with an area of ​​more than 500 m2, an addressable system is already cheaper than a non-addressable one. And the larger the area, the greater the winnings in money. True, not all experts who participated in our survey agreed with this statement. Some have rightly noted that it is not so much a matter of area as the number of protected premises and their location - factors that determine the configuration and ramifications of the system being created. (And they immediately proposed several addressless schemes for big house out of 20 premises using easy-to-control control panels, which are no more expensive than address ones.) There is, apparently, some truth in both statements - for each specific object it is necessary to select its own system, optimally suitable both in terms of technical parameters and price. And in order to get several alternative options and choose the best one, you should contact not just one company, but several at once.

But everyone agreed that address systems are cheaper to maintain. It’s cheaper because they find the fault themselves - all that remains is to fix it.

Equipment for analogue addressable systems has the highest cost. If, for example, an addressable threshold detector from SYSTEM SENSOR costs an average of $15, then a detector for an addressable analogue system from APOLLO costs $50, and from ESSER costs $90. The high cost of detectors, and therefore The systems assembled on their basis are still limited by their use in city apartments and private houses.

Having installed a fire alarm system, you should be prepared for the fact that the costs will not be limited to this. It will be necessary to pay regularly (at least once every six months, or better once a quarter) to call a specialist to carry out preventive work (the list of necessary actions and their frequency are indicated in the passports of the alarm control panel and detectors). For small SPS, the cost of such work is approximately 1000 rubles, for complex ones, naturally, it is more expensive, but, fortunately, not directly proportional to the cost of the system. It is better not to undertake them yourself - you may lose the warranty (it is usually given for a year, after which a contract for post-warranty service is concluded).

And one last thing to say at the end of this part of the review. In the field of electronic protection of an individual home, a fire alarm is usually an integral part security and fire system and is controlled by one control panel. Those working in such security systems The devices are already called differently - PPKOP, that is, fire and security control panels. But we are not discussing such systems today - unfortunately, the scope of the review is too small.

The editors would like to thank NPO PULSE, the FORMULA SAFETY group of companies, the INTEGRATED SECURITY alliance, and System Sensor Fair Detectors for their assistance in preparing the material.

As you know, a day of data center downtime costs tens or even hundreds of millions of dollars. For continuous operation, the data center must be protected from many hazards, including fire. In large American and European data centers, aspiration systems for early detection of fires are actively used for this purpose.

Specifics of fire detection in data centers

A data center is a high-tech facility that consumes more electricity than a typical office. An important requirement for data centers is maintaining a certain indoor air temperature. This purpose is served by a special air conditioning system, which creates internal air flows between and inside the racks, ensuring the removal of excess heat and a comfortable temperature for equipment operation.

Such a complex air conditioning system requires a special approach to fire detection. The fact is that in the presence of strong air currents, conventional fire detectors are ineffective for detecting smoke or heat radiation. Smoke driven by air currents may not enter the smoke chamber of the detector. And if it does get into the chamber, then by that moment the maximum concentration of smoke in the room has been reached, so that when the detector is triggered, the spread of fire is already inevitable. Therefore, modern data centers use active aspiration fire alarm systems.

Currently, aspiration fire alarm systems are produced only abroad; their main manufacturers are Bosch, Safe Fire Detection, Securiton, System Sensor and Xtralis (it owns the Vesda and Icam equipment brands, the latter was recently purchased by it).

Systems of this class, for example, Vesda and Icam from Xtralis, Titanus from Bosch Security or aspiration detectors System Sensor of the same company, are already used in many countries around the world at facilities of this type, including in Russia.

Historical reference In 1967, American researchers Ahlquist & Charlson created for the first time a nephelometer device to measure the transparency of air and the degree of its pollution, allowing one to control the content of carbon dioxide on city streets. This device was improved and released to the market in the United States. In 1970, Australia's CSIRO used the nephelometer in bushfire research. A little later, the CSIRO was contacted by the APO, the main postal department, with an order to study the problem of fire prevention in postal services. The purpose of the study was to find the most suitable technology for fire protection of telephone exchanges, computer rooms and cable tunnels. The sources of risk at these sites were cables that were heated by electric current or from hot plates. In this study, CSIRO used nephelometers to monitor smoke levels in ventilation ducts. Subsequently this study gave impetus to the development of a highly sensitive device capable of detecting smoke at an early stage of a fire. The release of an improved version of this device to the market was a huge leap in the development of early smoke detection systems.

It should be noted that the requirements of some international insurance companies already stipulate the use of early fire detection systems, including as a means of reducing insurance payments. And in the regulations of the largest international IT companies, the early fire detection system is part of the fire safety system.

Principle of operation

Aspiration systems are early fire detection systems. As a rule, they have a modular architecture that allows the system to be adapted to specific operating conditions and building layout. The main components of such a system are a pipeline for drawing air from the controlled area and the detector itself, which can be placed anywhere inside or outside the protected premises.

The pipeline is usually used PVC pipes. Using adapters, angles, tees and other accessories, you can create flexible networks of pipelines for air intake, taking into account the characteristics of each individual room. In this case, the aspiration detector itself creates a vacuum in the piping system to ensure a continuous intake of air from the monitored area through specially made holes. These actively produced air samples pass through a detection chamber where they are tested for smoke particle content. In addition, for example, in the VESDA system, dust and contaminants are first removed from the air sample using a built-in filter, and then the sample is fed into the aspirating detector chamber. This prevents contamination of the camera's optical surfaces.

The air sample enters a calibrated chamber in the detector where a laser beam passes through it. When smoke particles are present in the air, light scatters within the chamber and is immediately detected by the highly sensitive receiving system (Fig. 1). The signal is then processed and displayed on a bar graph display, alarm threshold indicators and/or graphic display. The sensitivity of the detector can be adjusted and the air flow is continuously monitored for detection of pipeline damage.

Aspiration detectors are conventionally divided into two categories. The first is PIB (Point in the box) type detectors, in which conventional high-sensitivity smoke detectors are used as a detection chamber, for example, ASD-Pro or LASD from System Sensor with a sensitivity of 0.03 to 3.33%/m. The second group is aspiration detectors such as VESDA, Icam or Titanus, which have their own built-in smoke detection chambers with a sensitivity range from 0.005 to 20%/m for VESDA, from 0.001 to 20%/m for Icam and from 0.05 to 10%/m m at Titanus. We will consider only detectors of the second group, since they have the largest sensitivity range compared to PIB, which makes it possible to detect a fire at the wire melting stage and set the highest threshold for starting a gas fire extinguishing system in data center premises.

Features and Benefits

Classic fire alarm systems do not go off until there is smoldering or fire. At this stage of the fire, fighting the fire becomes difficult. The most important advantage of aspiration systems is that they detect incipient fires and provide early warning of a fire. The smoke detection camera's intelligent processor analyzes the data received and decides whether it matches any typical fire patterns. At the same time, external factors that can cause false alarms are suppressed.

So, what are the main advantages of aspiration systems?

1. Reliable fire detection for early warning. Highly sensitive sensors detect a fire at its earliest stage - in the pyrolysis phase, even before visible smoke particles spread (for example, when a wire or other electronic element of equipment begins to melt). In most cases, such systems prevent significant material damage, since they quickly identify a failed element that can be de-energized, preventing an incipient fire from entering the active phase. In addition, aspiration systems make it possible not to activate the active (usually gas) fire extinguishing system and save the funds required for recharging gas cylinders.

2. Reducing the number of false positives. Thanks to intelligent signal processing from sensors in aspiration systems, external factors such as dust, drafts or electrical interference, which often cause false alarms, are suppressed. This ensures greater sensitivity and reliability of the system, even in rooms with high ceilings or extreme temperatures, as well as in dirty or high humidity environments.

3. Quick installation and easy maintenance. Detectors can be installed anywhere, both indoors and outdoors, to make them easier for service technicians to access. Aspiration systems are invisible in the room, and their maintenance does not require high qualifications. Information about all faults, such as pipeline damage, filter contamination, etc., is displayed on the display screen. Thus, personnel do not have to spend a lot of time identifying system malfunctions; it can be serviced as information becomes available.

The main and fundamental difference between aspiration systems and conventional systems with passive smoke sensors is the active sampling of air from communication and server cabinets of the data center, using a built-in fan operating on the principle of a vacuum cleaner. Another important difference is the higher sensitivity of the detectors, which makes it possible to detect smoke particles invisible to the human eye, with a concentration of 0.005%/m for the VESDA system, 0.001% for the Icam or 0.05% for the Titanus.

An important feature is the presence of a built-in (like the VESDA system) and/or external filter where the intake air is cleaned. Such filters allow the operation of aspiration systems in heavily contaminated rooms without constant cleaning or replacement of laser chambers, which, in turn, increases the service life of the system and reduces its maintenance costs.

Areas of use

In some cases, the use of aspiration systems brings tangible results compared to conventional ones passive detectors. First of all, these are enterprises and companies where the continuity of production or business processes is of paramount importance, and downtime is unacceptable. These are, for example, telecommunication systems and server financial organizations, municipal facilities and medical sterile rooms (operating rooms), energy and transport systems. Aspiration systems are also useful when it is necessary to eliminate false activation of the active fire extinguishing system, which leads to large expenditures of time and money for the restoration of the facility.

Aspiration systems are preferred in areas where smoke detection is difficult, such as high air flows or high atrium spaces ( shopping centers, gyms, theaters, museums, etc.). They are also used in rooms where access for Maintenance impossible or difficult; they are optimal for protecting the space behind suspended ceiling and under raised floors, elevator shafts, industrial areas, air ducts, and prisons and other places of detention. Another area of ​​application is in extreme environmental conditions: with heavy dust, gas contamination, humidity, very high or very low temperatures(for example, in power plants, paper or furniture factories, auto repair shops, mines). Finally, aspiration systems are used if it is important to preserve the design of the room and smoke detection devices need to be hidden.

Construction of an aspiration system in a data center

Typically, data center equipment is located in locked cabinets, so the most effective solution to protect these areas is to sample from the cabinets. In the case of aspiration systems in data centers, tubes with suction holes are routed over racks with installed equipment. The flexible tubing system allows sampling both above and inside cabinets using capillaries, providing the most reliable smoke detection in fully enclosed cabinets, as well as in cabinets with top ventilation (Figure 2).

How much does fire protection cost? The cost of a fire protection solution for a specific data center depends on the volume and area of ​​the premises, as well as the number of separately protected system components. In any case, this cost does not exceed 1% of the cost of equipment installed in the data center. For example, the price of a 15-channel Icam detector, capable of protecting 15 racks of equipment, is 10-11 thousand euros, the deviceVESDA VLP, which can protect up to 2000 sq.m., costs 4-5 thousand euros, and Titanus protects up to 400 sq.m. and costs 2000-4000 euros.

Active air suction and its subsequent analysis for the content of smoke particles in the aspiration chamber makes it possible to build a system in such a way that air flows in the room do not affect smoke detection. For example, using the Icam sensor, you can protect up to 15 racks by laying a separate capillary tube in each of them, and also provide targeting, determining the location of the fire with the accuracy of an individual cabinet. The principle of operation of the Icam sensor is the alternate intake of air from each tube and its further analysis for the content of smoke particles in the detection chamber.

The Titanus system has a ROOM-IDENT function that provides early fire detection and location. One detector can monitor up to five rooms or five racks using only one tube. The process of determining the source of fire by the ROOM-IDENT system includes four stages, and the result is displayed on the detector.

Stage 1(Normal Mode): The piping is used to collect and evaluate air samples in multiple rooms.

Stage 2(early fire detection): air suction and analysis. If smoke is present, an alarm will immediately sound for early response.

Stage 3(reverse circulation): when the alarm signal is activated, the suction fan is turned off and the second, discharge fan is turned on, blowing all smoke particles out of the pipeline in the opposite direction.

Stage 4(location determination): after the pipeline is purged, the direction of air movement changes again. Based on measurements of the time it took for smoke particles to reach the detection module, the system determines the location of the fire.

Using a flexible piping system, with a single VESDA sensor it is possible, for example, to monitor the space not only above the racks, but also behind the false ceiling and false floor, as well as cable trays, which are found in any data center and are often a source of fire. In addition, VESDA system detectors are built into a rack, which saves space and ensures the design uniformity of all equipment in the data center.

Another key point in organizing a reliable fire detection system is air intake directly from the supply and exhaust ventilation grille of the room. The resulting smoke inevitably enters the air flow, so installing a pipe system with intake holes on the air return grille of the circulation system ensures instant detection of an incipient fire at a very early stage.

Taking air samples directly next to the exhaust ventilation grille allows you to catch smoke particles in the air even if the created air flows have bypassed all other intake pipes in the room. This is due to the fact that all the air contained in the room circulates through the exhaust ventilation, which means that not a single particle of smoke contained in the air will pass past the intake opening (Fig. 3).

Possibility of setting different levels fire danger allows you to program the system for appropriate reactions at different stages of fire development, for example, turning off air conditioning equipment or starting active fire extinguishing systems. For example, you can set several pre-alarm thresholds or the highest sensitivity to determine the moment of melting of equipment elements. If this sensitivity threshold is exceeded, a pre-alarm signal will be transmitted to the fire station so that personnel can identify the melting point and turn off the power to the equipment, preventing the spread of the fire.

You can also set the sensitivity to medium, and the system will detect the moment of heavy smoke in the room, when it is difficult to find the place or equipment that is causing the smoke. If this sensitivity threshold is exceeded, you can program the system to turn off the air conditioners. The lowest sensitivity is set for the level of smoke in the room, when it is impossible to prevent further spread of the fire without active fire extinguishing systems. When this sensitivity threshold is reached, the gas fire extinguishing system is programmed to turn on (Fig. 4).

Turning on fire extinguishing systems is the second stage of preventing the spread of fire in a data center, when the development of a fire can no longer be stopped using simple actions: turning off a smoking server, air conditioning systems, etc. For active fire extinguishing, as a rule, gas systems fire extinguishing systems using two principles for organizing fire extinguishing in a data center. The first one is general gas fire extinguishing when extinguishing is carried out total area Data center. The second is rack gas fire extinguishing, when a separate rack is extinguished. The latter principle applies to racks with special-purpose equipment, where data loss will cost more than installing and operating a fire suppression system. But this is a topic for a separate article.

  

Early detection of a fire in a data center can prevent the loss of equipment and critical data, as well as forced downtime, associated with financial and material costs for the company. Investing in reliable system Fire alarms in data centers guarantee the organization protection against future costs for the restoration of electronic equipment and information lost in a fire. Sometimes these financial losses are incomparably greater than the cost of an early fire detection system.

This system is designed to detect the initial stage of a fire, transmit notification of the place and time of its occurrence and, if necessary, turn on automatic fire extinguishing and smoke removal systems.

An effective fire danger warning system is the use of alarm systems.

The fire alarm system must:

* - quickly identify the location of the fire;

* - reliably transmit a fire signal to the receiving and control device;

* - convert the fire signal into a form convenient for perception by the personnel of the protected facility;

* - remain immune to the influence of external factors other than fire factors;

* - quickly identify and transmit notification of faults that impede the normal functioning of the system.

They will be equipped with fire-fighting automatic equipment industrial buildings categories A, B and C, as well as objects of national importance.

The fire alarm system consists of fire detectors and converters that convert fire factors (heat, light, smoke) into an electrical signal; a monitoring and control station that transmits a signal and turns on a light and sound alarm; and automatic installations fire extinguishing and smoke removal.

Detecting fires at an early stage makes them easier to extinguish, which largely depends on the sensitivity of the sensors.

Automatic fire extinguishing systems

Automatic fire extinguishing systems are designed to extinguish or localize a fire. At the same time, they must also perform the functions of an automatic fire alarm.

Settings automatic fire extinguishing must meet the following requirements:

* - the response time must be less than the maximum permissible time for free development of a fire;

* - have the duration of action in the extinguishing mode necessary to extinguish the fire;

* - have the required supply intensity (concentration) of fire extinguishing agents;

* - reliability of operation.

In premises of categories A, B, C, stationary fire extinguishing installations are used, which are divided into aerosol (halocarbon), liquid, water (sprinkler and deluge), steam, and powder.

Sprinkler systems for extinguishing fires with sprayed water have become the most widespread at present. To do this, a network of branched pipelines is installed under the ceiling, on which sprinklers are placed at the rate of irrigation with one sprinkler from 9 to 12 m 2 of floor area. There must be at least 800 sprinklers in one section of the water system. The floor area protected by one sprinkler type SN-2 should be no more than 9 m 2 in rooms with increased fire hazard (when the amount of combustible materials is more than 200 kg per 1 m 2; in other cases - no more than 12 m 2. The outlet hole in the sprinkler head is closed with fusible lock (72°C, 93°C, 141°C, 182°C), when melted, water sprays, hitting the deflector. The intensity of irrigation of the area is 0.1 l/s m 2.

Sprinkler networks must be under pressure capable of delivering 10 l/s. If at least one sprinkler is opened during a fire, a signal is given. Control and alarm valves are located in visible and accessible places, and no more than 800 sprinklers are connected to one control and alarm valve.

In fire hazardous areas, it is recommended to supply water immediately over the entire area of ​​the room. In these cases, group action units (deluge units) are used. Deluge sprinklers are sprinklers without fusible locks with open holes for water and other compounds. At normal times, the water outlet to the network is closed by a group action valve. The intensity of water supply is 0.1 l/s m 2 and for rooms with increased fire danger (with the amount of combustible materials 200 kg per 1 m 2 or more) - 0.3 l/s m 2.

The distance between drenchers should not exceed 3 m, and between drenchers and walls or partitions - 1.5 m. The floor area protected by one deluge should be no more than 9m2. During the first hour of fire extinguishing, at least 30 l/s must be supplied

The installations allow automatic measurement of controlled parameters, recognition of signals in the presence of an explosive and fire hazardous situation, conversion and amplification of these signals, and issuance of commands to turn on actuators of protection.

The essence of the process of stopping an explosion is the inhibition of chemical reactions by feeding into the combustion zone fire extinguishing compounds. The possibility of stopping an explosion is due to the presence of a certain period of time from the moment the conditions of the explosion arise until its development. This period of time, conventionally called the induction period (f ind), depends on the physico-chemical properties of the combustible mixture, as well as on the volume and configuration of the protected apparatus.

For most flammable hydrocarbon mixtures, fiind is about 20% of the total explosion time.

In order for an automatic explosion protection system to meet its intended purpose, the following condition must be met:< ф инд, то есть, время срабатывания защиты должно опережать время индуктивного периода.

The conditions for the safe use of electrical equipment are regulated by the PUE. Electrical equipment is divided into explosion-proof, suitable for fire hazardous areas, and normal. In explosive areas It is allowed to use only explosion-proof electrical equipment, differentiated by levels and types of explosion protection, categories (characterized by a safe gap, that is, the maximum diameter of the hole through which the flame of a given combustible mixture is not able to pass), groups (characterized by T c of a given combustible mixture).

In hazardous areas and areas external installations special electric lighting equipment made in an anti-explosion version is used.

Smoke hatches

Smoke hatches are designed to ensure that adjacent rooms are smoke-free and to reduce the concentration of smoke in the lower zone of the room in which the fire occurred. By opening smoke hatches, more favorable conditions are created for the evacuation of people from a burning building, and the work of fire departments to extinguish the fire is facilitated.

To remove smoke in the event of a fire in the basement, the standards provide for the installation of windows measuring at least 0.9 x 1.2 m for every 1000 m 2 of area basement. The smoke hatch is usually closed with a valve.

Currently, most methods for detecting forest fires involve the personal presence of rescuers: patrolling, observation from towers and helicopters, as well as the use of space data. All measures taken are certainly effective in the absence of abnormal heat. But, during a period of drought, when fires simultaneously engulf vast territories in various parts of the country, the question of more advanced monitoring and early warning systems for forest fires becomes acute.

Forest fire detection system

Innovative developments in this direction have made it possible to create a completely unique “Forest fire detection” system. Unlike all currently existing methods of fighting fires, this system works automatically, with virtually no human intervention, alerting the operator at the most early stages fire detection.

“Forest fire detection” is a large-scale system of sensors that allows:

• Conduct continuous video surveillance.
• Detect smoke early.
• Automatically notify rescue services.
• Predict the scale of development of the fire source.
• Calculate the amount of forces aimed at extinguishing the fire.

The equipment is equipped with an autonomous power supply system and has high degree protection from various weather conditions and force majeure circumstances. This means that the system will not fail during a thunderstorm and will allow detection of areas affected by lightning.

How to purchase a system

Company "Xorex-Service", representing technology "Forest fire detection" on the Belarusian market, has established itself as a reliable partner in the field of IT technologies. All equipment promoted by the company undergoes mandatory certification and is of excellent quality.

Each order is processed individually:

1. At the initial stage, highly qualified specialists will assess the area, taking into account all the features of the relief, the availability of infrastructure, and even the weather conditions of the provided territory.
2. At the second stage, all work on installing and configuring the equipment will be carried out, taking into account all the individual characteristics identified earlier.
3. After preparation, the company’s specialists will train your organization’s personnel to use the system and provide ongoing support from their side. These are the guarantees of service!

What’s also attractive is that you can see for yourself the effectiveness "Forest fire detection" having tried our system. You will definitely be pleased with the team of professionals and the cost of system maintenance. And timely forecasting of the terrible natural disaster will help avoid many irreversible consequences of forest fires.