E.1 Estimated mass of GOTS, which should be stored in the installation, is determined by the formula

where - the mass of GOTS, intended for creation in the volume of placing a fire extinguishing concentration in the absence of artificial air ventilation, is determined by formulas:

For GOTV - liquefied gases, with the exception of carbon dioxide:

For GOTS - compressed gases and carbon dioxide

here is the calculated volume of the protected room, the m. The calculated volume of the room includes its internal geometric volume, including the volume of the ventilation system, air conditioning, air heating (to sealed valves or dampers). The volume of equipment in the room is not deducted from it, except for the volume of solid (impenetrable) building elements (columns, beams, foundations for equipment, etc.);

Coefficient, taking into account the leakage of the gas extinguishing substance from vessels;

Coefficient, taking into account the loss of gas fire extinguishing agent through the opening of the room;

The density of the gas fire extinguishing agent, taking into account the height of the protected object relative to the sea level for the minimum temperature in the room, kg / m is determined by the formula

here is the density of the steam of the gas fire extinguishing agent at a temperature of 213 K (20 ° C) and atmospheric pressure of 101.3 kPa;

The minimum air temperature in the protective room, K;

Correction coefficient, taking into account the height of the object relative to the sea level, the meanings of which are shown in Table d.11 of Appendix D;

Regulatory volume concentration,% (about.).

The values \u200b\u200bof the regulatory extinguishing concentrations are given in Appendix D.

Mass of the residue of GOTV in pipelines, kg, determined by the formula

where - the volume of the entire pipeline layout of the installation, m;

The density of the residue is at a pressure, which is available in the pipeline after the end of the mass of the gas extinguishing agent into the protected room;

The work of the residue of the GOTV in the module that is accepted on the TD on the module, kg, on the number of modules in the installation.

Note - For liquid combustible substances that are not given in Appendix D, the regulatory bulk fire extinguishing concentration of GOTS, all the components of which under normal conditions are located in the gas phase, can be defined as a product of a minimum volumetric concentration on a security coefficient equal to 1.2 for all GOTV , with the exception of carbon dioxide. For a security sophofer is 1.7.

For GOT HOTS under normal conditions in the liquid phase, as well as mixtures of GOTOS, at least one of the components of which under normal conditions are in the liquid phase, the normative fire extinguishable concentration is determined by multiplying the volumeting fire extinguishing concentration on the security coefficient of 1.2.

The methods for determining the minimum volumetric concentration and fire extinguishing concentration are set forth in GOST R 53280.3.

E.2 The coefficients of the equation (E.1) are defined as follows.

E.2.1 The coefficient, taking into account the leakage of the gas fire extinguishing agent from the vessels of 1.05.

E.2.2 The coefficient, taking into account the loss of the gas fire extinguishing agent through the opening of the room:

where is the parameter that takes into account the location of the openings in the height of the protected room, M · s.

The numerical values \u200b\u200bof the parameter are selected as follows:

0.65 - at the location of the openings at the same time in the lower (0-0.2) and the upper area of \u200b\u200bthe room (0.8-1.0) or simultaneously on the ceiling and on the floor of the room, and the area of \u200b\u200bopenings in the lower and the upper part is approximately equal range half of the total area of \u200b\u200bopenings; 0.1 - at the arrangement of the openings only in the upper zone (0.8-1.0) of the protected room (or on the ceiling); 0.25 - when the openings are location only in the lower zone (0-0, 2) the protected room (or on the floor); 0.4 - with approximately uniform distribution of the opening area over the entire height of the protected room and in all other cases;

The parameter of the accumulatory room, m,

where is the total area of \u200b\u200bopenings, m;

The height of the room, m;

The regulatory time is filing GOTV to the protected room, p.

E.3 Fire extinguishing Fires A (except for the glowing materials specified in 8.1.1) should be carried out in premises with a parameter of leakage not more than 0.001 m.

The value of the mass to extinguish fires subclass is aimed by the formula

where - the value of the massmall of the normative volume concentration of H-heptane carving, is calculated by formulas (2) or (3);

The coefficient that takes into account the view of the fuel material.

The coefficient values \u200b\u200bare accepted equal: 1.3 - to extinguish paper, corrugated paper, cardboard, fabrics, etc. in piles, rolls or folders; 2.25 - for premises with the same materials, in which the access of firefighters after the end of the work is excluded. For other fires, subclass A, besides those specified in 8.1.1, is denied equal to 1.2.

At the same time it is allowed to increase the regulatory time of filing GOTS at times.

In the event that the calculated amount of GOTOS is determined using the coefficient 2.25, the reserve of GOTV can be reduced and determined by the use of the coefficient1.3.

You should not open the protected room in which access is allowed, or disrupt its tightness in another way within 20 minutes after the AUGP is triggered (or before the arrival of fire protection units).

Appendix J.

Hydraulic calculation is the most difficult stage when creating augpt. It is necessary to choose the diameters of the pipelines, the number of nozzles and the area of \u200b\u200bthe output section, calculate the real output time of GOTV.

How will we count?

First you need to decide where to take the methodology and formula for hydraulic calculation. Open the set of rules of the SP 5.13130.2009, Appendix W and we see there only the methodology for calculating the carbon dioxide fire extinguishing of low pressure, and where is the technique for other gas extinguishing substances? We look at paragraph 8.4.2 and see: "For the remaining installations, it is recommended to produce according to the methods agreed in the prescribed manner."

Programs for calculation

Let us turn for help from gas fire extinguishing equipment manufacturers. In Russia, there are two methods for hydraulic calculations. One has been developed and copied many times with leading Russian manufacturers of equipment and approved by VNIIPO, based on its basis, "Salzon", "Salute" software. Another developed by the company "Takt" and agreed by DND MES, based on its tact gas software.

Methods are closed to most designer engineers and serve to internal use of automatic gas fire extinguishing manufacturers. If you agree, it will be shown to you, but without special knowledge and experience, the hydraulic calculation will be difficult.

Fire extinguishing

Selection and calculation of the gas fire extinguishing system

A. V. Merkulov, V. A. Merkulov

CJSC "Artsok"

The main factors affecting the optimal choice of the installation of gas fire extinguishing (UGP) are given: the type of combustible load in the protected room (archives, focusing, radio-electronic equipment, technological equipment, etc.); The magnitude of the protected volume and its non-medicality; type of gas extinguishing agent (GOT); The type of equipment in which the GOTS must be stored, and the type of UGP: centralized or modular.

The right choice of gas fire extinguishing installation (UGP) depends on many factors. Therefore, the purpose of this work is to identify the main criteria affecting the optimal choice of the installation of gas fire extinguishing and the principle of its hydraulic calculation.

The main factors affecting the optimal selection of gas fire extinguishing installation. First, the type of combustible load in the protective room (archives, focusing, radio-electronic equipment, technological equipment, etc.). Secondly, the magnitude of the protected volume and its non-mercy. Third, the type of gas heat-stewing substance. Fourth, type of equipment in which the gas fire extinguishing agent should be stored. Fifth, the type of gas fire extinguishing installation: centralized or modular. The last factor can only take place if you need fire protection two or more rooms on one object. Therefore, we consider the mutual influence of only four above the listed factors, i.e. In the assumption that the facility requires fire protection only one room.

Of course, the right choice of gas fire extinguishing should be based on optimal technical and economic indicators.

It should be especially noted that any of the gas fire extinguishing substance allowed to eliminate the fire regardless of the type of combustible material, but only when creating a regulatory extinguishing concentration in the protected volume.

The mutual influence of the factors listed above on the technical and economic parameters of the installation of gas fire extinguishing will be appreciated

from the condition that the following gas fire extinguishers are allowed in Russia: references 125, reference 318c, chladone 227ea, reference 23, CO2, K2, AG and mixture (No. 2, AG and CO2), which has an inergen trademark.

According to the method of storage and methods for controlling gas fire extinguishing substances in gas fire extinguishing modules (IHL), all gas fire extinguishes can be divided into three groups.

The first group includes chladone 125, 318c and 227ea. These chladones are stored in the gas fire extinguishing module in a liquefied type of gas-displacer, most often nitrogen. Modules with listed chladones, as a rule, have a working pressure not exceeding 6.4 MPa. Control of the amount of chladone during the operation of the installation is carried out on the pressure gauge installed on the gas fire extinguishing module.

Claudone 23 and CO2 make up the second group. They are also stored in liquefied form, but are displaced from the gas fire extinguishing module under pressure from their own saturated vapors. The operating pressure of modules with the listed gas flares must have a working pressure of at least 14.7 MPa. During operation, the modules must be installed on weighing devices that provide continuous control of the mass of chladone 23 or CO2.

The third group includes K2, AG and Inergen. These gas fire extinguishes are stored in gas fire extinguishing modules in a gaseous state. Further, when we consider the advantages and disadvantages of gas extinguishing substances from this group, we will dwell only on nitrogen.

This is due to the fact that N2 is the most effective (the smallest fire extinguishing concentration) and has the smallest cost. Control of the mass of the listed gas fire extinguishes is carried out on a pressure gauge. LH or inergen is stored in modules at a pressure of 14.7 MPa and more.

Gas fire extinguishing modules, as a rule, have a container of cylinders not exceeding 100 liters. At the same time, the modules with a capacity of more than 100 liters, according to PB 10-115, are subject to registration in the State University of Russia, which entails a sufficiently large number of restrictions on their use in accordance with the indicated rules.

The exceptions are isothermal modules for liquid carbon dioxide (mew) with a capacity from 3.0 to 25.0 m3. These modules are designed and manufactured for storage in gas fire extinguishing installations of carbon dioxide in quantities exceeding 2500 kg. Modules areothermal for liquid carbon dioxide are equipped with refrigeration units and heating elements, which allows maintenance of pressure in an isothermal tank in the range of 2.0 - 2.1 MPa at ambient temperature from minus 40 to plus 50 ° C.

Consider at the examples, as each of the four factors affect the technical and economic indicators of the installation of gas fire extinguishing. The mass of the gas fire extinguishing agent was calculated according to the method described in the NPB 88-2001.

Example 1. It is required to protect radio-electronic equipment indoor of 60 m3. The room is conditionally hermetic, i.e. K2 "0. The results of the calculation in the table. one.

Economic rationale Tab. 1 In specific figures has a certain difficulty. This is due to the fact that the cost of equipment and gas fire extinguishing agents from manufacturers and suppliers are different. However, there is a general trend, which is that the cost of the gas fire extinguishing module increases with an increase in the capacity of the cylinder. 1 kg of CO2 and 1 m3 n are close at a price and two orders of magnitude less than the cost of chladones. Table analysis. 1 shows that the cost of installing gas fire extinguishing with Claudo-Nom 125 and CO2 is comparable in magnitude. Despite the significantly higher cost of chladone 125 compared with carbon dioxide, the total price of refrigerant 125 - the gas fire extinguishing module with a capacity of 40 liters will be comparable or even somewhat lower than the carbon dioxide kit is a gas fire extinguishing module with a cylinder 80 L - weight device. Uniquely, it is possible to state a significantly greater cost of installing gas fire extinguishing with nitrogen compared to two previously considered options, because Two modules are required with a maximum volume. It will take more space for

TABLE 1

Cold 125 36 kg 40 1

CO2 51 kg 80 1

of the two modules in the room and, naturally, the cost of two 100 liters modules will always be greater than the cost of the module with a volume of 80 l with a weight device, which is usually 4 - 5 times cheaper than the module itself.

Example 2. Room parameters are similar to example 1, but it is necessary to protect non-radio-electronic equipment, but an archive. The results of the calculation is similar to the first example in the table. 2.

Based on the analysis of Table. 2 You can unambiguously say that in this case the cost of installing gas fire extinguishing with nitrogen is significantly higher than the cost of gas fire extinguishing installations with candidle 125 and carbon dioxide. But in contrast to the first example, in this case, it can be more clearly to note that the lowest cost is the installation of gas fire extinguishing with carbon dioxide, because With a relatively small difference in the cost between the gas fire extinguishing module with a cylinder 80 and 100 liters, the price of 56 kg of chladone 125 significantly exceeds the cost of the weight device.

Similar dependencies will be traced if the volume of the protected room and / or increases its non-mercy, because All this causes a general increase in the number of any kind of gas fire extinguishing agent.

Thus, only on the basis of two examples it can be seen that it is clear that the optimal installation of gas fire extinguishing for fire protection can be selected only after consideration, at least two versions with different types of gas extinguishing substances.

However, there are exceptions when the installation of gas fire extinguishing with optimal technical and economic parameters cannot be applied due to certain limitations imposed on gas exhausting substances.

TABLE 2

Name of GOTV Number of GOTOS Capacity MHP Ballon, L Number IHL, pcs.

Cold 125 56 kg 80 1

CO2 66 kg 100 1

Such restrictions primarily refers to the protection of specialized objects in the seismic zone (for example, nuclear power facilities, etc.), where the installation of modules in seismic resistant frames is required. In this case, the use of chladone 23 and carbon dioxide is excluded, because Modules with these gas fire extinguishing substances should be installed on weight devices that exclude their rigid fastening.

Fire protection of premises with constantly present personnel (air traffic controllers, halls with nuclear power plants, etc.) are presented to the toxicity of gas fire extinguishing substances. In this case, the use of carbon dioxide is excluded, because The bulk fire extinguishing concentration of carbon dioxide in the air is fatal for humans.

When protecting the volumes of more than 2000 m3 from an economic point of view, the use of carbon dioxide was most acceptable to the isothermal module for liquid carbon dioxide compared to all other gas extinguishing substances.

After conducting a feasibility study, the amount of gas extinguishing substances needed to eliminate fire and a preliminary number of gas fire extinguishing modules becomes known.

Nozzles must be installed in accordance with the scrawl cards specified in the technical documentation of the manufacturer of the manufacturer of the nozzles. The distance from the nozzles to the ceiling (overlapping, suspended ceiling) should not exceed 0.5 m using all gas fire extinguishing substances, except for K2.

Pipe layout, as a rule, should be symmetrical, i.e. Nozzles should be equally removed from the main pipeline. In this case, the consumption of gas fire extinguishes through all the nozzles will be the same, which will ensure the creation of a uniform fire extinguishing concentration in the protected amount. Typical examples of symmetric pipe wiring are shown in Fig. 1 and 2.

When designing a pipe wiring, it should also take into account the correct compound of the discharge pipelines (rows, taps) from the main.

The cruciform compound is possible only under the condition where the costs of gas extinguishing substances 01 and 02 are equal in size (Fig. 3).

If 01 Ф 02, then the opposite compounds of rows and taps with the main pipeline must be made in the direction of the movement of gas fire extinguishes by the distance b, exceeding 10 d, as shown in Fig. 4, where D is the inner diameter of the main pipeline.

There are no restrictions on the spatial connection of pipes when designing a pipe wiring of gas fire extinguishing, there is no restrictions when using gas extinguishing substances belonging to the second and third groups. And for the pipe wiring of the installation of gas fire extinguishing with gas extinguishing substances of the first group there are a number of restrictions. This is caused by the following.

When reducing the chladone 125, 318c or 227ea in the gas fire extinguishing module with nitrogen to the required pressure of nitrogen, is partially dissolved in the listed chladones, and the amount of dissolved nitrogen in chladones in proportion to pressure pressure.

B\u003e 10d ^ n

After opening the shut-off-starting device of the gas fire extinguishing module under the pressure of the gas-displacer, the chladone with a partially dissolved nitrogen on the pipe wiring enters the nozzles and through them goes into the protected volume. In this case, the pressure in the system "modules - pipe wiring" decreases as a result of the expansion of the volume occupied by nitrogen in the process of displacing the refrigeration, and the hydraulic resistance of the pipe wiring. A partial selection of nitrogen from the liquid chladone phase occurs and a two-phase medium "mixture of the liquid chladone phase is a nitrogen gas". Therefore, to the pipe wiring of the installation of gas fire extinguishing, which applies the first group of gas extinguishing substances, a number of restrictions are superimposed. The main purpose of these restrictions is aimed at preventing the separation of the two-phase medium inside the pipe wiring.

When designing and installing, all tubular compounds of the gas fire extinguishing installation must be performed as shown in Fig. 5, and it is forbidden to perform them in the form shown in Fig. 6. Rangers are shown the direction of the flow of gas fire extinguishes in pipes.

In the process of designing the installation of gas fire extinguishing in axonometric form, the pipe wiring diagram, the length of the pipes, the number of nozzles and their high-altitude stamps are determined. To determine the internal diameter of the pipes and the total area of \u200b\u200bthe outlet holes of each nozzle, it is necessary to perform hydraulic calculation of the gas fire extinguishing installation.

The method of performing hydraulic calculation of the installation of gas fire extinguishing with carbon dioxide is provided. The calculation of the installation of gas fire extinguishing with inert gases is not a problem, because In this case, the course of inert-

gas occurs in the form of a single phase gas medium.

Hydraulic calculation of the installation of gas fire extinguishing that use chladones 125, 318C and 227EA as a gas flavoring substance, represents a complex process. The use of the hydraulic calculation technique created for chladone 114V2 is unacceptable due to the fact that in this technique the flow of refrigerated pipes is considered in the form of a homogeneous fluid.

As noted above, the flow of refriges 125, 318c and 227ee by pipes occurs in the form of a two-phase medium (gas - liquid), and with a decrease in pressure in the system, the density of the gas-liquid medium is reduced. Therefore, to maintain the constant mass flow rate of gas extinguishing substances, it is necessary to increase the rate of gas-liquid medium or the inner diameter of pipelines.

Comparison of the results of mynthematical tests with the release of refrigerations of 318c and 227ea from the gas fire extinguishing unit showed that the test data was more than 30% differ from the calculated values \u200b\u200bobtained according to the method that does not take into account the solubility of nitrogen in chladone.

The effect of solubility of the gas-oscillator is taken into account in the methods of hydraulic calculation of the installation of gas fire extinguishing, in which HL-DON 13B1 is used as a gas fire extinguishing substance. These techniques do not have a generalizing nature. Designed for the hydraulic calculation of the installation of gas fire extinguishing only with Coldone 13B1 at two values \u200b\u200bof the pressure of the MGP nitrogen - 4.2 and 2.5 MPa and; With four values \u200b\u200bin operation and six values \u200b\u200bin the operation of the refilling coefficient of the refinement modules.

Considering the above, a task was set and developed a method of hydraulic calculation of the installation of gas fire extinguishing with chladones 125, 318C and 227EA, namely: at a given total hydraulic resistance of the gas fire extinguishing module (inputs to the siphon tube, siphon tube and a locking device) and a known pipe The installation of the gas fire extinguishing is to find the distribution of the mass of the refrigerated on the extent that passed through separate nozzles, and the expiration time of the calculated mass of the chladone from the nozzles to the protected volume after the simultaneous opening of the shut-off-starting device of all modules. When creating a technique, a nonstationary flow of a two-phase gas-liquid mixture "Cold-nitrogen" in a system consisting of gas fire extinguishing modules, pipelines and nozzles, which demanded knowledge of the gas-liquid mixture parameters (field pressure, density and speed fields) at any point of the pipeline system at any time .

In this regard, pipelines were divided into elementary cells in the direction of axes by planes perpendicular to the axes. For each elementary volume, the equations of continuity, the amount of movement and state were recorded.

At the same time, the functional dependence between pressure and density in the equation of state of the gas-liquid mixture was associated with the use of the Henry law under the assumption of homogeneity (homogeneity) of the gas-liquid mixture. Nitrogen solubility coefficient for each of the chladone under consideration was determined experimentally.

To perform hydraulic calculations of the gas fire extinguishing installation, a Fortran calculation program has been developed, which received the name "ZALP".

The hydraulic calculation program allows for a given scheme of the installation of gas fire extinguishing, in general, includes:

Gas fire extinguishing modules, fired by gas fire extinguishing substances with supercharged nitrogen to pH pressure;

Collector and main pipeline;

Switchgear;

Distribution pipelines;

Nozzles on the discharges, determine:

Installation inertia;

The release time of the calculated mass of gas fire-stewing substances;

The release time of the actual mass of gas flares; - Mass flow of gas extinguishing substances through each nozzle. Approbation of the methodology of the hydraulic calculation "2Arr" was carried out by the operation of three existing gas fire extinguishing settings and on an experimental stand.

It was found that the results of the calculation of the developed technique satisfactorily (with an accuracy of 15%) coincide with the experimental data.

The hydraulic calculation is performed in the following sequence.

UPB 88-2001 is determined by the calculated and actual mass of chladone. From the condition of the maximum permissible coefficient of filling the module (reference 125 - 0.9 kg / l, the refrigerations of 318c and 227ea - 1.1 kg / l) is determined by the type and number of gas fire extinguishing modules.

The pressure of the pH of gas extinguishing substances is given. As a rule, pH is taken in the range from 3.0 to 4.5 MPa for modular and from 4.5 to 6.0 MPa for centralized installations.

A diagram of the tubular layout of the installation of gas fire extinguishing with the length of the pipes, the high-altitude stones of the pipe wiring and nozzles connections. The internal diameters of these pipes are pre-set and the total area of \u200b\u200bnozzles outlets from the condition that this area should not exceed 80% of the area of \u200b\u200bthe inner diameter of the main pipeline.

The listed parameters of the installation of gas fire extinguishes are made to the program "2Arr" and a hydraulic calculation is performed. The calculation results may have several options. Below will look at the most typical.

The release time of the estimated mass of the gas flares is a tr \u003d 8-10 ° C for a modular installation and tr \u003d 13 -15 C for centralized, and the difference between the nozzles do not exceed 20%. In this case, all parameters of the installation of gas fire extinguishing are chosen correctly.

If the release time of the calculated mass of the gas fire extinguishing agent is less than the values \u200b\u200bindicated above, then the inner diameter of the pipelines and the total area of \u200b\u200bthe nozzles holes should be reduced.

Upon exceeding the normative time of the release of the calculated mass of the gas fire extinguishing agent, an increase in the pressure of the gas extinguishing substance in the module should be increased. If this event does not allow regulatory requirements, it is necessary to increase the volume of the gas-displacer in each module, i.e. Reduce the filling coefficient of the gas flares module, which entails an increase in the total number of modules in the gas fire extinguishing unit.

The implementation of regulatory requirements for the cost difference between the nozzles is achieved by a decrease in the total area of \u200b\u200bthe outlet nozzles.

LITERATURE

1. NPB 88-2001. Fire extinguishing and alarm installation. Norms and design rules.

2. SNiP 2.04.09-84. Fire automation of buildings and structures.

3. Fire Protection Equipment - Automatic Fire Extinguishing Systems Using Halogenated Hydrocarbns. Part I. Halon 1301 Total Flooding Systems. ISO / TC 21 / SC 5 N 55E, 1984.

Method for calculating the mass of the gas fire extinguishing agent for mouthgas fire extinguishing anovok when extinguishing in bulk

1. The calculated mass of GOTV, which should be stored in the installation, is determined by the formula

where
- Mass of GOTS, intended for creating a fire extinguishing concentration in the volume in the absence of artificial air ventilation, is determined by formulas:

for got - liquefied gases, with the exception of carbon dioxide

; (2)

for GOTS - compressed gases and carbon dioxide

, (3)

where - the calculated volume of the protected room, m 3.

In the calculated area of \u200b\u200bthe room, its internal geometric volume is included, including the volume of the ventilation system, air conditioning, air heating (to sealed valves or dampers). The volume of equipment in the room is not deducted from it, except for the volume of solid (impermeable) building elements (columns, beams, foundations for equipment, etc.);

- coefficient, taking into account the leakage of the gas extinguishing substance from the vessels;
- coefficient, taking into account the losses of the gas fire extinguishing agent through the opening of the room; - The density of the gas fire extinguishing agent taking into account the height of the protected object relative to the sea level for the minimum indoor temperature , kg  M -3, determined by the formula

, (4)

where - Density of the vapor gas fire extinguishing agent at temperatures \u003d 293 K (20 C) and atmospheric pressure of 101.3 kPa;
- the minimum air temperature in the protective room, K; - correction coefficient that takes into account the height of the object relative to the sea level, the values \u200b\u200bof which are shown in Table 11 of Annex 5;
- Regulatory volume concentration,% (vol.).

The values \u200b\u200bof the regulatory concentrations () are shown in Appendix 5.

Mass of the residue of GOTV in pipelines
, kg, determined by the formula

, (5)

where - the volume of the entire pipeline layout of the installation, m 3;
- The density of the residue of the HOTV at a pressure, which is available in the pipeline after the end of the mass of the gas fire extinguishing agent into the protected room.

- the product of the residue of GOTV in the module ( M. b.), which is accepted by TD on the module, kg, on the number of modules in the installation .

Note. For liquid combustible substances that are not given in Appendix 5, the regulatory bulk fire extinguishing concentration of GOTS, all the components of which under normal conditions are in the gas phase, can be defined as a product of a minimum volumetric fire extinguishing concentration on a security coefficient equal to 1.2 for all GOTS, for The exception of carbon dioxide. For CO 2, the safety coefficient is 1.7.

For GOT HOTS under normal conditions in the liquid phase, as well as mixtures of GOTOS, at least one of the components of which under normal conditions are in the liquid phase, the normative fire extinguishable concentration is determined by multiplying the volumeting fire extinguishing concentration on the security coefficient of 1.2.

The methods for determining the minimum volumetric fire extinguishing concentration and fire extinguishing concentration are set out in the NPB 51-96 *.

1.1. The coefficients of equation (1) are defined as follows.

1.1.1. The coefficient, taking into account the leakage of the gas extinguishing substance from the vessels:

.

1.1.2. The coefficient, taking into account the losses of the gas fire extinguishing agent through the opening of the room:

, (6)

where
- Parameter that takes into account the location of the openings in the height of the protected room, m 0.5  s -1.

The numerical values \u200b\u200bof the parameter are selected as follows:

0, 65 - at the location of the openings at the same time in the lower (0 - 0.2)
and the upper area of \u200b\u200bthe room (0, 8 - 1.0) or simultaneously on the ceiling and on the floor of the room, and the area of \u200b\u200bopenings in the lower and the upper part are approximately equal and constituted half the total area of \u200b\u200bopenings; \u003d 0.1 - when the openings are located only in the upper zone (0.8 - 1.0) of the protected room (or on the ceiling); \u003d 0.25 - at the location of the openings only in the lower zone (0- 0.2) of the protected room (or on the floor); \u003d 0.4 - with approximately uniform distribution of the area of \u200b\u200bopenings over the entire height of the protected room and in all other cases.

- the parameter of the accuracy of the room, M -1,

where
- Total opening area, m 2.

The height of the room, m;
- The regulatory time of filing GOTV to the protected room.

1.1.3. The extinguishing of fires subclass A 1 (except for the glowing materials specified in paragraph 7.1) should be carried out in rooms with a parameter of leakage not more than 0.001 m -1.

The value of mass M p to extinguish fires subclass A 1 is determined by the formula

M p \u003d K 4. M R-hepta,

where M p-hepta is the value of mass M p for the normative volume concentration with H when hepta heptane, calculated by formulas 2 or 3;

K 4 is a coefficient that takes into account the form of a fuel material. The values \u200b\u200bof the coefficient K 4 are taken equal: 1.3 - to extinguish paper, corrugated paper, cardboard, tissues, etc. in piles, rolls or folders; 2.25 - for the premises with the same materials in which the access of firefighters is expelled after the end of the work of augps, the backup margin is calculated when it is valued to 4, equal to 1.3.

The filing time of the main reserve of GOTV with a value to 4, equal to 2.25, can be increased by 2.25 times. For other fires, the subclass A 1 value to 4 is taken equal to 1.2.

You should not open the protected premises or disrupt its tightness in another way for at least 20 minutes (or before the arrival of fire protection units).

When opening the premises must be in the presence of primary means of fire extinguishing.

For premises, in which the access of fire units is expelled after the end of the AUGP work should be used as a fire extinguishing of CO 2 with a coefficient of 2.25.

1. The average for the flow of carbon dioxide pressure in the isothermal tank , MPa is determined by the formula

, (1)

where - pressure in the reservoir when storing carbon dioxide, MPa; - pressure in the reservoir at the end of the issue of the estimated amount of carbon dioxide, MPa, is determined by Figure 1.

2. Average carbon dioxide consumption

, (2)

where
- the calculated amount of carbon dioxide, kg; - The regulatory time of supply of carbon dioxide, p.

3. The inner diameter of the supply (main) pipeline, m, is determined by the formula

where k. 4 - the multiplier is determined by Table 1; l. 1 - The length of the supply (main) pipeline for the project, m.

Table 1

Factor k. 4

4. The average pressure in the supply (main) pipeline at the input point in its protected room

, (4)

where l. 2 - the equivalent length of pipelines from the isothermal tank to the point in which the pressure is determined, M:

, (5)

where - The sum of the coefficients of the resistance of the shaped parts of pipelines.

5. Average pressure

, (6)

where r 3 - pressure at the input point of the supply (main) pipeline in the protected room, MPa; r 4 - Pressure at the end of the feed (main) pipeline, MPa.

6. Middle Consumption through nozzles Q. m. , kg  С -1, is determined by the formula

where - consumption coefficient through nozzles; A. 3 - the area of \u200b\u200bthe outlet of the nozzle, m 2; k. 5 - coefficient determined by the formula

. (8)

7. NASY NASADOV Determined by the formula

.

8. Internal distribution pipe diameter , m, calculated from the condition

, (9)

where - the diameter of the outlet of the nozzle, m.

R

R 1 =2,4

isso 1. Schedule to determine the pressure in isothermal

reservoir at the end of the issue of the estimated amount of carbon dioxide

Note. Relative mass of carbon dioxide Determined by the formula

,

where - initial mass of carbon dioxide, kg.

Appendix 7.

Methods for calculating the area of \u200b\u200bthe opening for discharge of overpressure in rooms protected by gas fire extinguishing

Square Operacy for resetting overpressure , m 2, is determined by the formula

,

where - extreme-permissible overpressure, which is determined from the condition of preserving the strength of building structures of the protected room or the equipment placed in it, MPa; - atmospheric pressure, MPa; - air density under operating conditions of a protected room, kg  M -3; - stock coefficient taken equal to 1.2; - coefficient that takes into account the change in pressure during its submission;
- the feeding time of GOTV, determined from the hydraulic calculation, C;
- The area of \u200b\u200bconstantly open openings (except for a discrepanent opening) in the enclosing room structures, m 2.

Value values
, are determined in accordance with Annex 6.

For GOTS - liquefied gases coefficient TO 3 =1.

For GOTS - compressed gases coefficient TO 3 is accepted equal:

for nitrogen - 2.4;

for Argon - 2.66;

for the composition "Inergen" - 2.44.

If the value of the expression on the right side of the inequality is less than or equal to zero, then the opening (device) is not required to reset the overpressure.

Note. The value of the area of \u200b\u200bthe opening is designed without taking into account the cooling effects of GOTV-liquefied gas, which can lead to a certain decrease in the opening area.

General provisions for calculating the installation of powder fire extinguishing modular type.

1. The source data for calculating and designing installations are:

geometric size of the room (volume, area of \u200b\u200benclosing structures, height);

open opening area in enclosing structures;

operating temperature, pressure and humidity in the protective room;

a list of substances, materials located in the room, and the indicators of their fire danger corresponding to them the class of fire according to GOST 27331;

type, magnitude and diagram of the distribution of fire load;

the presence and characteristics of ventilation systems, air conditioning, air heating;

characteristics and placement of technological equipment;

the presence of people and their evacuation paths.

technical documentation for modules.

2. The installation calculation includes a definition:

the number of modules intended for fire extinguishing;

evacuation time, if available;

installation time of installation;

the necessary reserve of powder, modules, components;

type and the required number of detectors (if necessary) to ensure the operation of the installation, signal-starting devices, power sources for starting the installation (for cases of paragraph 8.5).

Methods for calculating the number of modules for modular installations of powder fire extinguishing

1. Capturing the protected volume

1.1. Extinguishing of the entire protected volume

The number of modules to protect the volume of the room is determined by the formula

, (1)

where
- The number of modules needed to protect the room, pcs.; - the volume of protected premises, M 3; - the volume protected by one module of the selected type is determined by the technical documentation (hereinafter referred to as the application document) on the module, m 3 (taking into account the geometry of spraying - forms and sizes of the protected volume declared by the manufacturer); = 11.2 - the coefficient of uneven spraying of powder. When placing nozzles on the border maximum allowed (by documentation for the module) height to = 1.2 or is determined by the documentation for the module.

- Reserve coefficient, taking into account the shaders of a possible spotlight, depending on the relationship of the area, shaded equipment , to protected area S. y. and is defined as:

for
,

Shading area - is defined as the area of \u200b\u200bthe protected area, where it is possible to form a focus of fire, to which the movement of the powder from the nozzle-sprayer in a straight line is barrier with impermeable structural elements.

For
It is recommended to install additional modules directly in the shaded zone or in a position that eliminates shading; When performing this condition k. it is accepted equal to 1.

- the coefficient that takes into account the change in the extinguishing efficiency of the powder used relative to the combustible substance in the protected zone compared to gasoline A-76. Determined in Table 1. In the absence of data, it is determined experimentally according to the methods of VNIIPO.

- coefficient, taking into account the degree of leakage of the premises. \u003d. 1 + B. F. negle , where F. neg \u003d. F / F. pOM - The ratio of the total area of \u200b\u200bleaks (openings, cracks) F. to the total surface of the room F. pOM , coefficient IN Defined in Figure 1.

IN

20

FN / F, FB / F

Figure 1 Schedule to determine the coefficient in the calculation of the coefficient.

F. n. - area of \u200b\u200bleakage at the bottom of the room; F. in - An area of \u200b\u200bleakage at the top of the room, the F-total area of \u200b\u200bthe leaks (openings, cracks).

For pulse fire extinguishing installations coefficient IN Can be determined by documentation for modules.

1.2. Local fire extinguishing

The calculation is carried out in the same way as when heating throughout the volume, taking into account PP. 8.12-8.14. Local volume V. n. protected by one module is determined by the documentation for modules (taking into account the geometry of spraying - forms and sizes of the local protected volume declared by the manufacturer), and the protected volume V. z. determined as the volume of an object increased by 15%.

With local cargo by volume is accepted \u003d 1.3, allowed to receive other values \u200b\u200bgiven in the documentation for the module.

2. Fire extinguishing on the area

2.1. Extinguishing

The number of modules needed for fire extinguishing on the area of \u200b\u200bthe protected area is determined by the formula

- The local area protected by one module is determined by the documentation for the module (taking into account the geometry of spraying - the forms and sizes of the local protected area declared by the manufacturer), and the protected area Determined as an area of \u200b\u200ban object, increased by 10%.

With local cargo in the area, it is accepted \u003d 1.3, it is allowed to receive other values. to 4 shown in the documentation for the module or reasonable in the project.

As S. n. the area of \u200b\u200bthe maximum rank of the center of class B, the extinguishing of which is ensured by this module (determined by the documentation for the module, m 2).

Note. In the case of obtaining, when calculating the number of fractional numbers modules, the following is received in order of more than a greater integer.

When protection in the area, taking into account the constructive and technological features of the protected object (with a justification in the project), it is allowed to launch modules according to algorithms that provide seal protection. In this case, a part of the area has been taken for the protected area, a part of the project (passages, etc.) or constructive non-combustible (walls, partitions, etc.) solutions. The installation of the installation should not ensure the dissemination of the fire beyond the protected zone, calculated taking into account the inertia of the installation and the velocities of the fire distribution (for a specific type of combustible materials).

Table 1.

Coefficient Comparative efficiency of fire extinguishers

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Fill in the form fields to find out the cost of the gas fire extinguishing system.

The preference of domestic consumers in favor of effective fire extinguishing, in which to eliminate the fires of electrical equipment and fires of class A, B, C (according to GOST 27331), gas extinguishes are used, due to the advantages of this technology. Fire extinguishing with gas, in comparison with other fire extinguishes, is one of the most non-aggressive ways to eliminate fire foci.

When calculating the fire extinguishing system, the requirements of the regulatory documents, the specifics of the object, and also determine the type of gas installation - modular or centralized (possibility of extinguishing the fire in several rooms).
Automatic gas fire extinguishing installation consists of:

• cylinders or other tanks intended for the storage of the gas fire extinguishing agent,
• pipelines and direction valves that provide the supply of fire extinguishing agent, gas (chladon, nitrogen, CO2, argon, Элегаз, etc.) in a compressed or liquefied state to the heart rate,
• detection and control devices.

When making an application for the supply, installation of equipment or a fully all complex of services, customers of our company "Compass" are interested in estimates for gas fire extinguishing. Indeed, the information that this species refers to the "expensive" fire extinguishing methods is valid. However, the exact calculation of the fire extinguishing system produced by our specialists, taking into account all conditions, demonstrates that the automatic installation of gas fire extinguishing in practice may be the most efficient and beneficial for the consumer.

Calculation of fire extinguishing - the first stage of design design

The main task for those who order gas fire extinguishing is to calculate the value of the mass of gas, which will be required to eliminate fire in the room. As a rule, fire extinguishing on the area (length, height, room width) is calculated, other object parameters may be required under certain conditions:

• room type (server, archive, data center);
• the presence of open openings;
• in the presence of raised floor and a false platform to indicate their heights;
• minimum room indoor;
• types of combustible materials;
• type of fire extinguishing agent (optional);
• class in the explosion and fire hazard;
• remoteness of the dispatch / remote control from the protected room.

Customers of our company can preliminarily.