Estimated evacuation. The start time of the evacuation. - Calculation of the required evacuation time
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MINISTRY OF EDUCATION AND SCIENCE OF THE RUSSIAN FEDERATION FEDERAL AGENCY FOR EDUCATION State educational institution higher professional education "Orenburg State University"
Department of Life Safety
EVACUATION TIME CALCULATION
Introduction
1 Calculation allowable duration fire evacuation
2 Calculation of evacuation time
3 Calculation example
Annex A. Table AL - Categories of production
Annex B. Table B.1 - Degree of fire resistance for various buildings
Annex B. Table B.1 - average speed burnout and heat of combustion of substances and materials
Appendix D. Table D.1 - Linear speed of flame propagation on the surface of materials
Appendix E. Table E. 1 - Delay time for the start of evacuation
Appendix E. EL table - Human projection area. Table E. 2 - Dependence of speed and intensity of traffic on the density of the human flow
Introduction
One of the main ways to protect against the damaging factors of emergencies is the timely evacuation and dispersal of personnel of facilities and the population from dangerous areas and disaster zones.
Evacuation - a set of measures for the organized withdrawal or removal of personnel of facilities from emergency zones or emergency situations, as well as the life support of evacuees in the area of deployment.
When designing buildings and structures, one of the tasks is to create the most favorable conditions for the movement of a person in case of a possible emergency and ensuring his safety. Forced movement is associated with the need to leave the premises or building due to the danger (fire, accident, etc.). Professor V.M. Predtechensky was the first to consider the fundamentals of the theory of people's movement as an important functional process inherent in buildings for various purposes.
Practice shows that the forced movement has its own specific features that must be taken into account in order to preserve the health and life of people. It is estimated that about 11,000 people die each year in fires in the United States. The largest catastrophes with human casualties have recently occurred in the United States. Statistics show that largest number casualties are accounted for by fires in buildings with mass stay of people. The number of victims in some fires in theaters, department stores and other public buildings has reached several hundred people.
The main feature of forced evacuation is that in the event of a fire, already in its very initial stage, a person is in danger as a result of the fact that the fire is accompanied by the release of heat, products of complete and incomplete combustion, toxic substances, collapse of structures, which in one way or another threatens health or even human life. Therefore, when designing buildings, measures are taken so that the evacuation process can be completed at the required time.
The next feature is that the process of movement of people, due to the danger threatening them, instinctively begins simultaneously in one direction towards the exits, with a certain manifestation of physical effort on the part of the evacuees. This leads to the fact that the aisles quickly fill up with people at a certain density of human flows. With an increase in the density of flows, the speed of movement decreases, which creates a very definite rhythm and objectivity of the movement process. If during normal movement the evacuation process is arbitrary (a person is free to move at any speed and in any direction), then with a forced evacuation this becomes impossible.
An indicator of the effectiveness of the forced evacuation process is the time during which people can, if necessary, leave individual premises and the building as a whole.
The safety of forced evacuation is achieved if the duration of the evacuation of people from individual premises or buildings as a whole is less than the duration of the fire, after which there are hazardous effects for humans.
The short duration of the evacuation process is achieved by design, planning and organizational solutions, which are standardized by the relevant SNiPs.
Due to the fact that during forced evacuation, not every door, staircase or opening can provide a short-term and safe evacuation (dead-end corridor, a door to an adjacent room without an exit, a window opening, etc.), design standards stipulate the concepts of "evacuation exit" and "evacuation route ".
According to the norms (SNiP P-A. 5-62, clause 4.1) emergency exits doorways are considered if they lead from the premises directly to the outside; into the stairwell with access to the outside directly or through the vestibule; to the passage or corridor with direct access to the outside or to the stairwell; to neighboring premises on the same floor, having fire resistance of at least III degree, not containing industries related to fire hazard to categories A, B and C, and having direct access to the outside or to the stairwell (see Appendix A).
All openings, including doorways, that do not have the above features are not considered evacuation and are not taken into account.
To escape routes include those that lead to the emergency exit and provide safe movement within a certain time. The most common escape routes are walkways, corridors, foyers and stairs. Communication routes associated with a mechanical drive (elevators, escalators) do not belong to escape routes, since any mechanical drive is associated with energy sources that can fail in case of fire or accident.
Emergency exits are called those that are not used during normal traffic, but can be used if necessary during an emergency evacuation. It has been established that people usually use during forced evacuation the entrances that they used during normal traffic. Therefore, in rooms with a mass stay of people, emergency exits are not taken into account in the calculation of evacuation.
The main parameters characterizing the process of evacuation from buildings and structures are:
traffic density (D);
the speed of the human flow (v);
track capacity (Q);
traffic intensity (q) ;
length of escape routes, both horizontal and inclined;
escape route width .
Density of human flows. The density of human flows can be measured in various units. So, for example, to determine the length of a person's step and the speed of his movement, it is convenient to know the average length of the section of the evacuation route per person. The length of a person's step is taken equal to the length of the path section per person, minus the length of the foot (Figure 1).
Figure 1 - Scheme for determining the step length and linear density
In industrial buildings or premises with a small population, the density can be more than 1 m / person. The density, measured by the length of the path per person, is commonly called linear and is measured in m / person. Let's denote the linear density D.
A more illustrative unit for measuring the density of human flows is the density per unit area of the evacuation route and expressed in people / m 2. This density is called absolute and is obtained by dividing the number of people by the area of the evacuation route occupied by them and is denoted Dr. Using this unit of measurement, it is convenient to determine throughput escape routes and exits. This density can vary from 1 to 10-12 people/m 2 for adults and up to 20-25 people/m for schoolchildren.
At the suggestion of the candidate of technical sciences A.I. Milinsky, the flow density is measured as the ratio of the area of passages occupied by people to total area passages. This value characterizes the degree of filling of evacuation routes by evacuees. The part of the aisle area occupied by people is determined as the sum of the areas of horizontal projections of each person (Appendix E, table EL). The horizontal projection area of one person depends on age, character, clothing and ranges from 0.04 to 0.126 m 2. In each individual case, the projection area of one person can be determined as the area of an ellipse:
(1)
where a- width of a person, m; with- its thickness, m.
The width of an adult at the shoulders ranges from 0.38 to 0.5 m, and the thickness - from 0.25 to 0.3 m. Bearing in mind the different heights of people and some compressibility of the flow due to clothing, the density may in some cases exceed 1 mm. We will call this density relative or dimensionless, and denote D o .
Due to the fact that there are people of different ages, genders and different configurations in the flow, the data on the density of the flows are, to a certain extent, averaged values.
For calculations of forced evacuation, the concept is introduced estimated density of people flows. The estimated density of human flows means highest value density, possible when moving on any section of the evacuation route. Maximum possible meaning density is called limiting. By limiting is meant such a value of density, when exceeded, mechanical damage to the human body or asphyxia is caused.
If necessary, you can move from one density dimension to another. In this case, the following relations can be used:
Where f- the average size projection area of one person, m / person;
a- the width of a person, m.
With massive human flows, the length of the step is limited and depends on the density of the flows. If we take the average stride length of an adult human as 70 cm, and the length of the foot is 25 cm, then the linear density at which movement with the specified stride length is possible will be:
0,7+ 0,25 = 0,95.
In practice, it is believed that a step with a length of 0.7 m will remain even with a linear density of 0.8. This is explained by the fact that during mass flows a person advances his foot between those in front, which contributes to maintaining the length of the step.
Movement speed. Surveys of speeds at maximum densities showed that the minimum speeds on horizontal sections of the track range from 15 to 17 m/min. The design speed of movement, legalized by the design standards for premises with a mass stay of people, is assumed to be 16 m / min.
In sections of the evacuation route or in buildings where the flow density during forced movement is known to be less than the limit values, the speed of movement will be correspondingly higher. In this case, when determining the speed of forced movement, the length and frequency of a person's step are taken into account. For practical calculations, the speed of movement can be determined by the formula:
(4)
where P- the number of steps per minute, equal to 100.
The speed of movement at limiting densities down the stairs was 10 m/min, and up the stairs - 8 m/min.
output capacity. The specific throughput of exits is the number of people passing through an exit 1 m wide in 1 minute.
The smallest value of specific throughput, obtained empirically, at a given density is called the calculated specific throughput. The specific capacity of the exits depends on the width of the exits, the density of human flows and the ratio of the width of human flows to the width of the exit.
The norms set the capacity of doors with a width of up to 1.5 m, equal to 50 people / m-min, and a width of more than 1.5 m - 60 people / m-min (for limiting densities).
Dimensions of emergency exits. In addition to the size of evacuation routes and exits, the norms regulate their design and planning solutions that ensure organized and safe movement of people.
fire hazard production processes in industrial buildings characterized physical and chemical properties substances generated in production. Production of categories A and B, in which liquids and gases circulate, are of particular danger in case of fires due to the possibility of rapid spread of combustion and smoke in buildings, so the length of the paths for them is the smallest. In industries of category B, where solid combustible substances are handled, the rate of propagation of combustion is lower, the evacuation period can be somewhat increased, and, consequently, the length of evacuation routes will be longer than for the production of categories A and C. In industries of categories D and D, located in buildings of I and II degrees of fire resistance, the length of evacuation routes is not limited (to determine the category of the building, see Appendix A).
When rationing, we proceeded from the fact that the number of evacuation routes, exits and their sizes must simultaneously satisfy four conditions:
1) the greatest actual distance from the possible place of stay of a person along the line of free passages or from the door of the most remote room 1 f to the nearest emergency exit must be less than or equal to the required by the standards 1 tr
(5)
2) the total width of emergency exits and stairs provided for by the project, d f must be greater than or equal to the required
3) the number of emergency exits and ladders, for safety reasons, should, as a rule, be at least two.
4) the width of emergency exits and stairs should not be less or more than the values provided for by the standards.
Typically, in industrial buildings, the length of evacuation routes is measured from the most remote workplace to the nearest evacuation exit. Most often, these distances are normalized within the first stage of evacuation. This indirectly increases the total duration of the evacuation of people from the building as a whole. In multi-story buildings, the length of evacuation routes in the premises will be less than in single-story buildings. This is a completely correct position given in the norms.
The degree of fire resistance of the building also affects the length of the evacuation routes, as it determines the rate of propagation of combustion through the structures. In buildings of I and II degrees of fire resistance, the length of evacuation routes, other things being equal, will be greater than in buildings of III, IV and V degrees of fire resistance.
The degree of fire resistance of buildings is determined by the minimum fire resistance limits of building structures and the maximum limits for the spread of fire over these structures; when determining the degree of fire resistance, it is necessary to use Appendix B.
The length of evacuation routes for public and residential buildings is provided as the distance from the doors of the most remote room to the exit to the outside or to the stairwell with access to the outside directly or through the lobby. Usually, when assigning a distance limit, the purpose of the building and the degree of fire resistance are taken into account. According to SNiP P-L.2-62 "Public buildings", the length of the evacuation routes to the exit to the stairwell is insignificant and meets the safety requirements.
1 . Calculation of the permissible duration of evacuation in case of fire
In the event of a fire, the danger to humans is high temperatures, a decrease in the concentration of oxygen in the indoor air and the possibility of loss of visibility due to smoke in buildings.
The time to reach critical temperatures and oxygen concentrations for a person in a fire is called the critical duration of a fire and is denoted .
The critical duration of a fire depends on many variables:
(1.1)
where - the volume of air in the building or room under consideration, m 3;
with- specific isobaric heat capacity of gas, kJ/kg-deg;
t Kp - the critical temperature for humans, equal to 70 ° C;
t H - initial air temperature, °C;
- the coefficient characterizing the heat loss for heating structures and surrounding objects is taken on average equal to 0.5;
Q - heat of combustion of substances, kJ/kg, (Appendix B);
f - burning surface area, m 2 ;
P- weight burning rate, kg / m 2 -min (Appendix B);
v - linear speed of fire spread over the surface of combustible substances, m/min (Appendix D).
To determine the critical duration of a fire by temperature in industrial buildings using flammable and combustible liquids, you can use the formula obtained on the basis of the heat balance equation:
The free volume of the room corresponds to the difference between the geometric volume and the volume of the equipment or objects inside. If it is impossible to calculate the free volume, it is allowed to take it equal to 80% of the geometric volume.
The specific heat capacity of dry air at atmospheric pressure is 760 mm. rt. Art., according to tabular data is 1005 kJ / kg-deg at temperatures from 0 to 60 ° C and 1009 kJ / kg-deg at temperatures from 60 to 120 ° C.
With regard to industrial and civil buildings using solid combustible substances, the critical duration of a fire is determined by the formula:
By reducing the concentration of oxygen in the air of the room, the critical duration of the fire is determined by the formula:
where W02 is the oxygen consumption for the combustion of 1 kg of combustible substances, m / kg, according to the theoretical calculation, is 4.76 ogmin.
The linear speed of fire spread during fires, according to VNIIPO, is 0.33-6.0 m / min, more accurate data for different materials presented in Appendix G.
The critical fire durations for loss of visibility and for each of the gaseous toxic combustion products are longer than the previous ones listed above, therefore they are not taken into account.
From the values of the critical duration of the fire obtained as a result of the calculations, the minimum is selected:
The permissible duration of evacuation is determined by the formulas:
where and - respectively allowable duration
evacuation and critical fire duration during evacuation, min,
m - safety factor depending on the degree fire protection the building, its purpose and the properties of combustible substances formed in production or being the subject of interior furnishings or their decoration.
For spectacular enterprises with a grate stage separated from the auditorium fire wall and fire curtain, when fire-retardant treatment of combustible substances on the stage, the presence of stationary and automatic extinguishing agents and fire warning equipment m = 1,25.
For entertainment enterprises in the absence of a grate stage (cinemas, circuses, etc.) m = 1,25.
For spectacular enterprises with a stage for concert performances t=1,0.
For spectacular establishments with a grate stage and in the absence of a fire curtain and automatic extinguishing and fire warning equipment t= 0,5.
In industrial buildings with automatic extinguishing and fire warning means t = 2,0.
In industrial buildings in the absence of means of automatic extinguishing and fire warning t= 1,0.
When placing production and other processes in buildings of the III degree of fire resistance t= 0,65-0,7.
The critical duration of a fire for a building as a whole is set depending on the penetration time of combustion products and possible loss visibility in communication rooms located before leaving the building.
Experiments carried out on burning wood showed that the time after which loss of visibility is possible depends on the volume of the premises, the mass burning rate of substances, the speed of flame propagation over the surface of substances and the completeness of combustion. In most cases, a significant loss of visibility during the combustion of solid combustible substances occurred after critical temperatures for a person appeared in the room. The largest number smoke-forming substances occurs in the smoldering phase, which is characteristic of fibrous materials.
When fibrous substances are burned in a loosened state for 1-2 minutes, intense combustion from the surface takes place, after which smoldering begins with rapid smoke formation. When burning solid wood-based products, smoke formation and the spread of combustion products to adjacent rooms are observed after 5-6 minutes.
Observations have shown that at the beginning of an evacuation, the decisive factor for determining the critical duration of a fire is the effect of heat on the human body or a decrease in oxygen concentration. At the same time, it is taken into account that even slight smoke, in which satisfactory visibility is still maintained, can have a negative psychological impact on evacuees.
Estimating as a result the critical duration of the fire for the evacuation of people from the building as a whole, we can establish the following.
In case of fires in civil and industrial buildings, where the main combustible material is cellulose materials (including wood), the critical fire duration can be taken equal to 5-6 minutes.
In case of fires in buildings where fibrous materials are handled in a loosened state, as well as combustible and flammable liquids - from 1.5 to 2 minutes.
In buildings where people cannot be evacuated within the specified time, measures must be taken to create smoke-free escape routes.
In connection with the design of high-rise buildings, the so-called smoke-free stairs began to be widely used. Currently, there are several options for arranging smoke-free stairs. The most popular is the option with the entrance to the staircase through the so-called air zone. Balconies, loggias and galleries are used as an air zone (Figure 2, a, b).
Figure 2 - Smoke-free stairs: a - entrance to the stairwell through the balcony; b - entrance to the stairwell through the gallery.
2 . Calculation of evacuation time
The duration of the evacuation of people before leaving the building outside is determined by the length of the evacuation routes and the throughput of doors and stairs. The calculation is carried out for the conditions that the flow densities on the evacuation routes are uniform and reach maximum values.
According to GOST 12.1.004-91 (Appendix 2, clause 2.4), the total time for the evacuation of people consists of the interval "time from the occurrence
fire before the evacuation of people, t n uh, and estimated evacuation time, t p, which is the sum of the time of movement of the human flow in separate sections (t,) its route from the location of people at the time of the start of the evacuation to the evacuation exits from the premises, from the floor, from the building.
The need to take into account the time of the beginning of the evacuation for the first time in our country was established by GOST 12.1.004-91. Research carried out in various countries, showed that upon receiving a signal about a fire, a person will investigate the situation, notify about a fire, try to fight the fire, collect things, provide assistance, etc. The average value of the evacuation start delay time (in the presence of a warning system) can be low, but can also reach relatively high values. For example, a value of 8.6 microns was recorded during a training evacuation in a residential building, 25.6 minutes in the building of the World shopping center by fire in 1993.
Due to the fact that the duration of this stage significantly affects the total evacuation time, it is very important to know what factors determine its size (keep in mind that most of these factors will also affect the entire evacuation process). Based on existing work in this area, the following can be distinguished:
human condition: persistent factors (limitation of the sense organs, physical limitations, temporary factors (sleep / wakefulness), fatigue, stress, and also the state of intoxication);
notification system;
personnel actions;
social and family ties person;
fire fighting training and education;
building type.
The delay time for the start of the evacuation is taken according to Appendix D.
Estimated evacuation time (t P) should be defined as the sum of the time of movement of the human flow along separate sections of the path t f:
where - evacuation start delay time;
t 1 - time of movement of the human flow in the first section, min;
t 2 , t 3 , t i - time of movement of the human flow on each of the following sections of the route after the first, min.
When calculating, the entire path of the movement of the human flow is divided into sections (passage, corridor, doorway, flight of stairs, vestibule) with a length /, and a width bj. The initial sections are the passages between workplaces, equipment, rows of seats, etc.
When determining the estimated time, the length and width of each section of the escape route are taken according to the project. Path length flights of stairs, as well as on ramps is measured along the length of the march. Path length in doorway is taken equal to zero. An opening located in a wall with a thickness of more than 0.7 m, as well as a vestibule, should be considered an independent section of a horizontal track having a finite length.
The time of movement of the human flow along the first section of the path (t;), min, calculated by the formula:
(2.2)
where - length of the first section of the track, m;
The value of the speed of movement of the human flow along the horizontal path in the first section is determined depending on relative density D, m2/m2.
Density of the human flow (D\) on the first section of the path, m / m, is calculated by the formula:
where - number of people in the first section, people;
f is the average area of the horizontal projection of a person, taken according to Table E. 1 of Appendix E, m 2 / person;
and - length and width of the first section of the track, m
The speed V / of the movement of the human flow on the sections of the route following the first one is taken according to Table E.2 of Appendix E, depending on the value of the intensity of the movement of the human flow along each of these sections of the route, which is calculated for all sections of the route, including for doorways, according to the formula:
where , - the width of the considered i_th and the section of the track preceding it, m;
, - values of the intensity of the movement of the human flow along the considered i_mu and the previous sections of the path, m/min.
If the value , determined by formula (2.4), is less than or equal to the value q max, then the time of movement along the section of the path () per minute: in this case, the values q max, m/min should be taken according to Table 2.1.
Table 2.1 - Traffic intensity
If the value q h defined by formula (2.4), more q max, then the width bj of this section of the path should be increased by such a value at which the condition is met:
If it is impossible to fulfill the condition (2.6), the intensity and speed of the movement of the human flow along the section of the path i determined according to Table E.2 of Appendix E with the value D = 0.9 or more. In this case, the time of delay in the movement of people due to the resulting accumulation should be taken into account.
When merging at the beginning of the section i two or more human flows (Figure 3) traffic intensity ( }, m/min, calculated by the formula:
- the intensity of the movement of human flows, merging at the beginning of the section /, m / min;
i - width of sections of the confluence path, m;
- width of the section of the track under consideration, m.
If the value defined by formula (2.7), more q max, then the width - of this section of the path should be increased by such an amount that condition (2.6) is observed. In this case, the time of movement along the section i is determined by formula (2.5).
The intensity of traffic in a doorway with a width of less than 1.6 m is determined by the formula:
Where b _ opening width.
The time of movement through the opening is defined as the quotient of the number of people in the stream divided by the throughput of the opening:
Figure 3 - Confluence of human flows
3 . Calculation procedure
· Choose from the calculated critical fire durations the minimum one and use it to calculate the allowable duration of evacuation according to the formula (1.6).
· Determine the estimated time of evacuation of people in case of fire, using the formula (2.1).
· Compare the estimated and allowable evacuation time, draw conclusions.
4 . Calculation example
It is necessary to determine the time of evacuation from the office of employees of the enterprise "Obus" in the event of a fire in the building. Administrative building panel type, not equipped with an automatic alarm and fire warning system. The building is two-story, has dimensions in terms of 12x32 m, in its corridors 3 m wide there are schemes for evacuating people in case of fire. An office with a volume of 126 m 3 is located on the second floor in close proximity to the staircase leading to the first floor. Stairwells are 1.5 m wide and 10 m long. 7 people work in the office. In total, 98 people work on the floor. 76 people work on the ground floor. The scheme of evacuation from the building is shown in Figure 4
Figure 4 - Scheme of the evacuation of employees of the enterprise "Obus": 1,2,3,4 - stages of evacuation
4.1 Calculation of evacuation time
4.1.2. The critical duration of a fire in terms of temperature is calculated by formula (1.3), taking into account the furniture in the room:
4.1.3 The critical duration of a fire in terms of oxygen concentration is calculated using the formula (1.4):
4.1.4 Minimum fire duration by temperature
is 5.05 min. Permissible evacuation duration for a given
premises:
The delay time for the start of evacuation is assumed to be 4.1 minutes according to Table D. 1 of Appendix D, taking into account the fact that the building does not have automatic system fire alarms and alerts.
To determine the time of movement of people in the first section, taking into account the overall dimensions of the office 6x7 m, the density of the movement of people in the first section is determined by the formula (2.3):
According to Table E.2 of Appendix E, the speed of movement is 100 m/min, the intensity of movement is 1 m/min, thus. travel time for the first section:
4.1.7 The length of the doorway is assumed to be zero. The highest possible traffic intensity in the opening under normal conditions g mffic = 19.6 m/min, the traffic intensity in the opening 1.1 m wide is calculated by the formula (2.8):
q d = 2,5 + 3,75 * b= 2.5 + 3.75 * 1.1 = 6.62 m/min,
q d therefore, movement through the opening passes unhindered.
The time of movement in the opening is determined by the formula (2.9):
4.1.8. Since 98 people work on the second floor, the density of the human flow on the second floor will be:
According to table E2 of Appendix E, the speed of movement is 80 m/min, the intensity of movement is 8 m/min, i.o. time of movement along the second section (from the corridor to the stairs):
4.1.9 To determine the speed of movement on the stairs, the traffic intensity in the third section is calculated using formulas (2.4):
This shows that on the stairs the speed of the human flow is reduced to 40 m/min. Time to move down the stairs (3rd section):
4.1.10 When moving to the first floor, it mixes with the flow of people moving along the first floor. Density of the human flow for the first floor:
while the traffic intensity will be about 8 m/min.
4.1.11. When moving to the 4th section, the merging of human flows occurs, therefore the traffic intensity is determined by the formula (2.7):
According to Table E.2 of Annex E, the speed of movement is 40 m/min, so the speed of movement along the corridor of the first floor:
4.1.12 The tambour at the exit to the street has a length of 5 meters, in this section the maximum density of the human flow is formed, therefore, according to the application data, the speed drops to 15 m/min, and the time of movement along the tambour will be:
4.1.13 At the maximum density of the human flow, the intensity of traffic through the doorway to the street with a width of more than 1.6 m - 8.5 m/min, the time of movement through it:
4.1.13 Estimated evacuation time is calculated by formula (2.1):
4.1.14 Thus, the estimated time of evacuation from the offices of the "Obus" enterprise is more than allowed. Therefore, the building in which the enterprise is located must be equipped with a fire warning system, automatic alarm systems.
List of sources used
Occupational safety in construction: Proc. for universities / N.D. Zolotnitsky [i dr.]. - M.: graduate School, 1969. - 472 p.
Labor safety in construction (Engineering calculations in the discipline "Life safety"): Tutorial/ D.V. Koptev [i dr.]. - M.: Izd-vo ASV, 2003. - 352 p.
Fetisov, P.A. Fire Safety Handbook. - M.: Energoizdat, 1984. - 262 p.
Table physical quantities: Handbook./ I.K. Kikoin [and others]
Schreiber , D. Fire extinguishing agents. Physical and chemical processes during combustion and extinguishing. Per. with him. - M.: Stroyizdat, 1975. - 240 p.
GOST 12.1.004-91.SSBT. Fire safety. General requirements. - Input. from 07/01/1992. - M.: Publishing House of Standards, 1992. -78 p.
Dmitrichenko A.S. A new approach to the calculation of forced evacuation of people during fires / A.S. Dmitrichenko, S.A. Sobolevsky, S.A. Tatarnikov // Fire and Explosion Safety, No. 6. - 2002. - S. 25-32.
Annex A
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Characteristics of substances and materials located (circulating) in the room |
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A Explosive |
Combustible gases, flammable liquids with a flash point of not more than 28 ° C in such an amount that they can form explosive vapor-gas-air mixtures, upon ignition of which the calculated overpressure explosion in the room, exceeding 5 kPa. Substances and materials capable of exploding and burning when interacting with water, atmospheric oxygen or with each other in such an amount that the calculated overpressure of the explosion in the room exceeds 5 kPa |
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Explosive and fire hazardous |
Combustible dusts or fibers, flammable liquids with a flash point of not more than 28 ° C in such an amount that they can form explosive dust-air or vapor-gas-air mixtures, upon ignition of which an estimated excess explosion pressure in the room develops in excess of 5 kPa. |
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B1_B4 Fire hazardous |
Combustible and slow-burning liquids, solid combustible and slow-burning substances and materials (including dust and fibers), substances and materials that can only burn when interacting with water or with each other, provided that the premises in which they are available or apply, do not belong to categories A and B. |
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Non-combustible substances and materials in a hot, incandescent or molten state, the processing of which is accompanied by the release of radiant heat, sparks and flames; combustible gases, liquids and solids that are burned or disposed of as fuel. |
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Non-flammable substances and materials in a cold state. |
Annex B
Table B.1 - Degree of fire resistance for various buildings
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Degree of fire resistance |
Structural features |
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Buildings with load-bearing and enclosing structures made of natural or artificial stone materials, concrete or reinforced concrete using sheet and slab non-combustible materials |
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Same. It is allowed to use unprotected steel structures in the coatings of buildings |
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Buildings with load-bearing and enclosing structures made of natural or artificial stone materials, concrete or reinforced concrete. For ceilings it is allowed to use wooden structures, protected by plaster or slow-burning sheet, as well as board materials. There are no requirements for fire resistance limits and fire propagation limits for roofing elements, while attic wood roofing elements are subjected to fire retardant treatment. |
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Buildings are predominantly with a frame structural scheme. Frame elements - from steel unprotected structures. Enclosing structures - from profiled steel sheets or other non-combustible sheet materials with slow-burning insulation |
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The buildings are predominantly one-storey with a frame structural scheme. Frame elements - from solid or glued wood, subjected to fire-retardant treatment, providing the required fire spread limit. Enclosing structures - from panels or element-by-element assembly made with the use of wood or materials based on it. Wood and other combustible materials of building envelopes must be subjected to fire retardant treatment or protected from fire and high temperatures in such a way as to ensure the required fire spread limit. |
||
|
Buildings with load-bearing and enclosing structures made of solid or glued wood and other combustible or slow-burning materials, protected from fire and high temperatures by plaster or other sheet or plate materials. There are no requirements for fire resistance limits and fire propagation limits for roofing elements, while attic wood roofing elements are subjected to fire retardant treatment. |
||
|
The buildings are predominantly one-storey with a frame structural scheme. Frame elements - from steel unprotected structures. Enclosing structures - from profiled steel sheets or other non-combustible materials with combustible insulation. |
||
|
Buildings, for the bearing and enclosing structures of which there are no requirements for fire resistance limits and limits for the spread of fire |
Annex B
Table B.1 - Average burnout rate and calorific value of substances and materials
|
Substances and materials |
weight speed |
Heat of combustion |
|
|
burning hyu 3 , |
kJ-kg» 1 |
||
|
kg_ m-min» |
|||
|
diethyl alcohol |
|||
|
Ethanol |
|||
|
Turbine oil (TP_22) |
|||
|
Isopropyl alcohol |
|||
|
Isopentane |
|||
|
sodium metal |
|||
|
Wood (bars) 13.7% |
|||
|
Wood (furniture in residential and |
|||
|
administrative buildings 8-10%) |
|||
|
paper loosened |
|||
|
Paper (books, magazines) |
|||
|
Books on wooden shelves |
|||
|
Film triacetate |
|||
|
Carbolite products |
|||
|
Rubber SCS |
|||
|
Natural rubber |
|||
|
Organic glass |
|||
|
Polystyrene |
|||
|
Textolite |
|||
|
polyurethane foam |
|||
|
Staple fiber |
|||
|
Staple fiber in bales |
|||
|
Polyethylene |
|||
|
Polypropylene |
|||
|
Cotton in bales 190 kg x m |
|||
|
Cotton loosened |
|||
|
Flax loosened |
|||
|
Cotton + nylon (3:1) |
Annex D
Table D.1 - Linear speed of flame propagation on the surface of materials
|
Line speed |
||
|
Material |
flame spread |
|
|
on the surface |
||
|
Burnouts textile production in |
||
|
loosened state |
||
|
Wood in stacks at humidity, %: |
||
|
Wood (furniture in administrative and |
||
|
other buildings) |
||
|
Hanging fleecy fabrics |
||
|
Textiles in a closed warehouse at |
||
|
loading. 100 kg/m2 |
||
|
Paper rolls in a closed warehouse at |
||
|
loading 140 kg/m |
||
|
Synthetic rubber in a closed warehouse at |
||
|
loading over 230 kg/m |
||
|
Wooden coverings large workshops, |
||
|
wooden walls finished with wood |
||
|
fiber boards |
||
|
Furnace enclosing structures with |
||
|
insulation made of filling polyurethane foam |
||
|
Straw and reed products |
||
|
Fabrics (canvas, baize, calico): |
||
|
horizontally |
||
|
in the vertical direction |
||
|
Sheet polyurethane foam |
||
|
Rubber products in stacks |
||
|
Synthetic coating "Scorton" |
||
|
at T=180 °C |
||
|
Peat slabs in stacks |
||
|
AShv1x120 cable; APVGEZx35+1x25; |
||
|
АВВГЗх35+1х25: |
Annex D
Table E. 1 - Delay time for the start of evacuation
|
Type and characteristics of the building |
Time to delay the start of evacuation, min, with types of warning systems |
||||
|
Administrative, commercial and industrial buildings (visitors are awake, familiar with the layout of the building and the evacuation procedure) |
|||||
|
Shops, exhibitions, museums, leisure centers and other public buildings, (visitors are awake, but may not be familiar with the building layout and evacuation procedure) |
|||||
|
Dormitories, boarding schools (visitors may be in a state of sleep, but are familiar with the layout of the building and the evacuation procedure) |
|||||
|
Hotels and boarding houses (visitors may be in a state of sleep, and not familiar with the layout of the building and the evacuation procedure) |
|||||
|
Hospitals, nursing homes and similar establishments (a significant number of visitors may need assistance) |
|||||
|
Note: Characteristics of the warning system W1 - notification and evacuation control by the operator; W2 - use of pre-recorded typical phrases and information boards; W3 - fire alarm siren; W4 - no notification. |
Annex E
Table E.1 - Human projection area
Table E.2 - Dependence of speed and intensity of traffic on the density of the human flow
|
Flux density D, |
horizontal path |
Doorway |
stairs down |
stairs up |
||||
|
0.9 or more |
||||||||
|
Note. The table value of the traffic intensity in the doorway at a flow density of 0.9 or more, equal to 8.5 m / min, is set for a doorway with a width of 1.6 m or more. |
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USSR MINISTRY OF INTERNAL AFFAIRS
ALL-UNION ORDER "Badge of Honour" SCIENTIFIC RESEARCH INSTITUTE OF FIRE DEFENSE
MOSCOW 1989
2.1. General calculation procedure
2.1.1. Determination of the geometric characteristics of the room
2.1.2. The choice of design schemes for the development of a fire
2.1.3. Determination of the critical duration of a fire for the chosen scheme of its development
2.1.4. Determining the most dangerous scheme for the development of a fire in a room
2.1.5. Determining the required evacuation time
Appendix Initial data for calculations
Bibliography
When solving the problem, the following hazards fire: elevated ambient temperature; smoke leading to loss of visibility; toxic gases; reduced concentration oxygen. The determination of the required evacuation time was carried out under the condition that one of these factors reached the maximum permissible value for a person.
Designed for engineering and technical workers fire brigade, teachers, students of fire-technical educational institutions, employees of research, design, construction organizations and. institutions.
Tab. 4, appendix 1, bibliography: 4 titles.
The recommendations were developed by employees of the Ministry of Internal Affairs of the USSR T. G. Merkushkina, Yu. S. Zotov and V. N. Timoshenko.
INTRODUCTION
Feature modern construction- increase in the number of buildings with mass stay of people. These include indoor cultural and sports complexes, cinemas, clubs, shops, industrial buildings, etc. Fires in such premises are often accompanied by injury and death of people. First of all, this applies to fast-growing fires, which pose a real danger to humans within a few minutes after their occurrence and are characterized by an intense impact on people of dangerous fire factors (MF). Most reliable way ensuring the safety of people in such conditions - timely evacuation from the premises in which the fire broke out.In accordance with, each object must have such a space-planning and technical execution so that the evacuation of people from the premises is completed before the maximum permissible values of the RPP are reached. For this reason, the number, size and design evacuation routes and exits are determined depending on the required evacuation time, i.e. the time during which people must leave the premises without being exposed to a fire that is dangerous to life and health / 1 /. Data on the required evacuation time is also the initial information for calculating the level of safety of people in case of fires in buildings. Incorrect determination of the required evacuation time can lead to incorrect design decisions and an increase in the cost of buildings or to insufficient protection of people in the event of a fire.
In accordance with the recommendations of the work / 1 /, the required evacuation time is calculated as the product of the fire duration critical for a person and the safety factor. The critical duration of a fire is the time after which dangerous situation due to the achievement by one of the OFP of the maximum permissible value for a person. At the same time, it is assumed that each hazardous factor affects a person independently of the others, since the complex impact of various qualitative and quantitative combinations of MFs that change over time, characteristic of the initial period of fire development, is currently not possible to assess. The safety factor takes into account possible error when solving the task. It is taken equal to 0.8 / 1 /.
Thus, to determine the required time for evacuating people from the premises, it is necessary to know the dynamics of the magnetic field in the area where people stay (working area) and the maximum allowable values for a person for each of them. Among the OFP, which pose the greatest danger to people indoors in the initial period of a rapidly developing fire, can be attributed: elevated ambient temperature; smoke leading to loss of visibility; more toxic combustion products; reduced oxygen concentration.
The methodology for calculating the required evacuation time, set out in these recommendations, was developed on the basis of the theoretical and experimental studies the dynamics of RPP, acting at the critical stage of a fire for a person in premises for various purposes. As the maximum permissible levels of RPP for people, the values obtained as a result of biomedical studies of the impact on humans of various hazardous factors were used.
1. GENERAL PROVISIONS
The recommendations are intended to calculate the required time for the evacuation of people from premises for various purposes in which a fire occurs. The calculation formulas were obtained taking into account the following assumptions:- through open openings, only the displacement of gas from the room occurs;
- the absolute pressure of the gas in the room during a fire does not change;
- heat loss ratio in building construction to the heat power of the fire source is constant in time;
- the properties of the environment and the specific characteristics of the material burning during a fire (lower working calorific value, smoke-generating ability, specific output of toxic gases, etc.) are constant;
- the dependence of the burnt mass of material on time is a power function.
2. METHODOLOGY FOR CALCULATION OF THE NECESSARY TIME TO EVACUATE PEOPLE FROM PREMISES IN THE FIRE
2.1. General calculation procedureBased on the analysis of the design solution of the object, the geometric dimensions of the room and the height of the working areas are determined. The free volume of the room is calculated, which is equal to the difference between the geometric volume of the room and the volume of equipment or objects inside. If it is impossible to calculate the free volume, then it is allowed to take it equal to 80% of the geometric volume / 2 /.
Next are selected calculation schemes fire development, which are characterized by the type of combustible substance or material and the direction of the possible spread of the flame. When choosing design schemes for the development of a fire, one should focus primarily on the presence of flammable and combustible substances and materials, the rapid and intense burning of which cannot be eliminated by the forces of people in the room. Such substances and materials include: flammable and combustible liquids, loose fibrous materials (cotton, linen, fumes, etc.), hanging fabrics (for example, curtains in theaters or cinemas), scenery in entertainment enterprises, paper, wood shavings, some types polymer materials(e.g. soft polyurethane foam, plexiglass), etc.
For each of the selected fire development schemes, the critical duration of a fire for a person is calculated according to the following factors: elevated temperature; loss of visibility in smoke; toxic gases; reduced oxygen content. The obtained values are compared with each other and the minimum is selected from them, which is the critical duration of the fire no j-th calculated scheme.
Then the most dangerous scheme for the development of a fire in a given room is determined. For this purpose, for each of the schemes, the amount of material burned out by the time m j is calculated and compared with the total amount this material M j , which can be covered by fire according to the considered scheme. Design schemes, in which m j >M j , are excluded from further analysis. From the remaining design schemes, the most dangerous fire development scheme is selected, in which the critical fire duration is minimal.
The resulting value of t cr is taken as the critical duration of the fire for the premises under consideration.
The value of t cr determines the required time for the evacuation of people from a given room.
2.1.1. Determination of the geometric characteristics of the room
The geometric characteristics of the room used in the calculation include its geometric volume, the reduced height H and the height of each of the working zones h.
The geometric volume is determined based on the size and configuration of the room. The reduced height is found as the ratio of the geometric volume to the area of the horizontal projection of the room. Height working area calculated as follows:
where h otm - the height of the mark of the area where people are above the floor of the room, m; δ - floor height difference, zero with its horizontal arrangement, m.
It should be borne in mind that people who are at a higher level are exposed to the maximum danger in a fire. So, when determining the necessary time for people to evacuate from the stalls of an auditorium with an inclined floor, the value of h for the stalls must be calculated, focusing on the rows of seats remote from the stage (located at the highest elevation).
2.1.2. The choice of design schemes for the development of a fire
The time of occurrence of situations dangerous to humans during a fire in a room depends on the type of combustible substances and materials and the burning area, which, in turn, is determined by the properties of the materials themselves, as well as the way they are laid and resolved. Each calculation scheme for the development of a fire in a room is characterized by the values of two parameters A and n, which depend on the shape of the combustion surface, the characteristics of combustible substances and materials and are determined as follows.
1. For burning flammable and combustible liquids spilled on area F:
when burning a liquid at a steady rate (typical for volatile liquids)
where ψ is the specific steady-state mass burnout rate of the liquid, kg·m -2 s -1 ;
When a liquid burns at an unsteady speed
where τ st - settling time stationary mode liquid burnout, p.
2. For circular propagation of flame over the surface of a combustible material evenly distributed in a horizontal plane
, (2)
where V is the linear speed of flame propagation over the surface of the combustible material, m·s -1 .
3. For a vertical or horizontal burning surface in the form of a rectangle, one of the sides of which increases in two directions due to the spread of the flame (for example, the horizontal tension of the fire along the curtain after it has been covered with flame along its entire height)
, (3)
where b is the size of the combustion zone perpendicular to the direction of flame movement, m.
4. For vertical surface burning, having the shape of a rectangle (curtain burning, single decorations, combustible finishing or facing materials walls when ignited from below until the flame reaches the upper edge of the material)
where V G and V V are the average values of the horizontal and vertical speed of flame propagation over the surface of the material, m·s -1.
5. For a cylinder-shaped combustion surface (combustion of a package of decorations or fabrics placed with a certain gap).
Each considered calculation scheme is assigned a serial number (index j).
2.1.3. Determination of the critical duration of a fire for the chosen scheme of its development
The calculation of t cr j is made in the following sequence. First, the value of the complex B is found
where Q is the lower calorific value of the material covered by the tribe (under the considered scheme), MJ·kg -1; V - free volume of the room, m³.
Then the parameter is calculated by the formula
.
,
where t 0 is the initial temperature in the room, ° С;
B) loss of visibility
,
where α is the reflection coefficient (albedo) of objects on the escape routes; E - initial evacuation routes, lux; D - smoke generating capacity of the burning material, Np·m²·kg -1;
B) reduced oxygen content
,
where L О2 - oxygen consumption for combustion of 1 kg of burning material, kg kg -1
D) each of the gaseous toxic combustion products
,
where x is limit allowed content of this gas in the atmosphere of the room, kg m -3 (x CO2 \u003d 0.11 kg m -3; x CO \u003d 1.16 10 -3 kg m -3; x HCl \u003d 23 10 -6 kg m -3 / 3 /.
The critical duration of a fire is determined for a given design scheme
where i = 1, 2, ... n is the index of the toxic combustion product.
In the absence of special requirements, the values \u200b\u200bof α and E are taken to be 0.3 and 50 lux, respectively.
2.1.4. Determining the most dangerous scheme for the development of a fire in a room
After calculating the critical duration of a fire for each of the selected schemes of its development, the amount of material burned out by the time t cr j is found.
Each value in the considered j-th scheme compared with the indicator M j . Design schemes, in which m j >M j , as already noted, are excluded from further consideration. Of the remaining design schemes, the most dangerous one is selected, i.e. the one for which the critical duration is minimal t cr = min(t cr j ).
The resulting value of t cr is the critical duration of a fire for a given working area in the room under consideration.
2.1.5. Determining the required evacuation time
The required time for the evacuation of people from a given working area of the premises under consideration is calculated by the formula:
where k b - safety factor, k b = 0.8.
Initial data for calculations can be taken from Table. 1-4 applications or from reference literature.
2.2. Calculation examples
Example 1 Determine the necessary time for the evacuation of people from the auditorium of the cinema. The length of the hall is 25 m, the width is 20 m. The height of the hall from the side of the stage is 12 m, from the opposite side - 9 m. The length of the horizontal section of the butt near the stage at the zero level is 7 m. marks. The curtain weighing 50 kg is made of fabric with the following characteristics: Q = 13.8 MJ kg -1 ; D \u003d 50 Np m² kg -1; L O 2 , = 1.03 kg·kg -1 ; L CO2 \u003d 0.203 kg kg -1; L CO \u003d 0.0022 kg kg -1; ψ \u003d 0.0115 kg m² s -1; V B = 0.3 m s -1 ; V G \u003d 0.013 m s -1. The upholstery of the chairs is polyurethane foam covered with leatherette. The initial temperature in the hall is 25 °C, the initial illumination is 40 lx, the volume of items and equipment is 200 m³.
1. Define geometric characteristics premises.
The geometric volume is
The reduced height H is defined as the ratio of the geometric volume to the area of the horizontal projection of the room
.
The room contains two working areas: parterre and balcony. In accordance with the instructions given in section (2.1.1), we find the height of each working area
for stalls h = 3 + 1.7 - 0.5 - 3 = 3.2 m;Free volume of the room V = 5460 - 200 = 5260 m³.
for a balcony h \u003d 7 + 1.7 - 0.5 - 3 \u003d 7.2 m.
2. We select the design schemes of the fire. In principle, two variants of occurrence in this room are also possible: along the curtain and along the rows of chairs. However, the ignition of the leatherette upholstery of the chair from a low-calorie source is difficult to implement and can be easily eliminated by the forces of the people in the hall.
Consequently, the second scheme is practically unrealistic and disappears. Therefore, for the balcony
= 65 s. We make a similar calculation for the stalls:
The z value for the parterre is smaller than for the balcony. Consequently, the release of toxic combustion products will not be dangerous to humans in this working area either. Then for the stalls t cr = (151,102,160) = 102 s.
4. Check if the selected calculation scheme is dangerous
for a balcony m = 2.99 10 -5 (65)³ = 8.2 kg<50 кг;Therefore, the scheme is dangerous for both work areas.
for stalls m = 2.99 10 -5 (102)³ = 31.7 kg<50 кг.
5. We determine the necessary time for the evacuation of people
from the stalls t nb = 0.8 102 = 82 s = 1.4 min;Example 2 Determine the required time for the evacuation of people from the premises of the preparatory workshop of the flax mill, which has dimensions of 54 × 212 × 6 m. Combustible material (flax) in the amount of 1500 kg is evenly spread over an area of 230 × 18 m, another 250 kg are on a conveyor belt 2 m wide. the zone of people is located at around 8 m. The initial values of temperature and illumination in the room, respectively, are 20 ° C and 60 lux.
from the balcony t nb \u003d 0.8 65 \u003d 52 c \u003d 0.9 min.
H = 6 m; h = 1.8 + 1.7 + 0.5 0 = 3.5 m;
V \u003d 0.8 (54 212 6) \u003d 54950 m³.
2. We choose design schemes for the development of a fire. Since it is possible to ignite both stored and transported flax, there will be two such schemes. For the first of them, using formula (2), we find
A 1 \u003d 1.05 0.0213 (0.05)² \u003d 5.59 10 -5 kg s -2; n = 3
The values of ψ and V are taken from the appendix.
Accordingly, for the second scheme according to formula (3)
A 2 \u003d 0.0213 0.05 2 \u003d 2.13 10 -3 kg s -2; n = 2.
3. We calculate t kr1 and t kr2 according to the recommendations contained in section 2.1.3. We accept α = 0.3. We take the rest of the initial data from the condition of the problem, as well as from the application, given that during the combustion of flax, the most dangerous toxic combustion products are carbon monoxide and carbon dioxide.
Determine t cr1, B = 3227 kg; 
.
Then
(a negative number under the sign of the logarithm means that an increase in the CO content in this case is not dangerous and can be ignored);
(carbon dioxide is also not taken into account).
Thus t cr = (191,363,175) = 175 s.
We determine t cr2. B = 3227 kg; z = 1.32.
Then
An increase in the content of carbon monoxide and dioxide in the atmosphere in this case is also not dangerous for humans. Hence,
t cr2 = min(429, 374, 1119) = 374 s.
4. We define m 1 and m 2 as follows
m 1 \u003d 5.59 10 -5 (175)³ \u003d 300 kg;
m 2 \u003d 2.13 10 -3 (374)² \u003d 298 kg.
Since m 2 = 298 kg>M 2 = 250 kg, the second scheme is excluded from consideration. Therefore, t cr = t cr1 = 175 s.
5. We determine the required time for evacuating people from the premises t nb = 0.8 175 = 140 s = 2.3 min.
Example 3 It is required to find the necessary time for the evacuation of people from a machining shop measuring 104 × 72 × 16.2 m, in which an emergency oil spill and fire occurred on an area of 420 m². People are at zero. The time to establish a stationary regime of oil burnout is 900 s / 4 /. Oil burning characteristics:
Q \u003d 41.9 MJ kg -1; D \u003d 243 Np m² kg -1; L O 2 \u003d 0.282 kg kg -1; L CO 2 \u003d 0.7 kg kg -1; ψ = 0.03 kg m -2 s -1.
1. We determine the geometric characteristics of the room:
h = 1.7 m; V \u003d 0.8 104 72 16.2 \u003d 97044 m³.
2. For the case of non-stationary combustion of a liquid on a constant area, according to formula (1), we find:
table 2
Linear velocity of flame propagation over the surface of materials
| materials | Average linear velocity of flame propagation V×10², m s -1 |
| Wastes of textile production in a loosened state | 10,0 |
| Cord | 1,7 |
| Cotton loosened | 4,2 |
| Flax loosened | 5,0 |
| Cotton + nylon (3:1) | 2,8 |
| Wood in stacks at different humidity, in% | |
| 8-12 | 6,7 |
| 16-18 | 3,8 |
| 18-20 | 2,7 |
| 20-30 | 2,0 |
| over 30 | 1,7 |
| Hanging fleecy fabrics | 6,7-10 |
| Textiles in a closed warehouse with a load of 100 kg m -2 | 0,6 |
| Paper in rolls in a closed warehouse when unloading 140 kg m -2 | 0,5 |
| Synthetic rubber in a closed warehouse with a load of more than 290 kg m -2 | 0,7 |
| Large area wooden flooring, wooden walls and fibreboard walls | 2,8-5,3 |
| Straw and reed products | 6,7 |
| Fabrics (canvas, baize, calico): | |
| horizontally | 1,3 |
| in the vertical direction | 30 |
| in the normal direction to the surface of the tissues with a distance between them of 0.2 m | 4,0 |
Table 3
Smoke generating capacity of substances and materials
| Substances and materials | Smoke generating capacity D, Np m²kg -1 | |||||
| Smoldering | Combustion | |||||
| Butyl alcohol | - | 80 | ||||
| Gasoline A-76 | - | 256 | ||||
| ethyl acetate | - | 330 | ||||
| Cyclohexane | - | 470 | ||||
| Toluene | - | 562 | ||||
| Diesel fuel | - | 620 | ||||
| Wood | 345 | 23 | ||||
| Wood fiber (birch, aspen) | 323 | 104 | ||||
| Chipboard, GOST 10632-77 | 760 | 90 | ||||
| Plywood, GOST 3916-65 | 700 | 140 | ||||
| Pine | 759 | 145 | ||||
| Birch | 756 | 160 | ||||
| fibreboard(Fibreboard) | 879 | 130 | ||||
| PVC linoleum, TU 21-29-76-79 | 200 | 270 | ||||
| Fiberglass, TU 6-11-10-62-81 | 640 | 340 | ||||
| Polyethylene, GOST 16337-70 | 1290 | 890 | ||||
| Tobacco "Jubilee" 1 grade, rl. thirteen % | 240 | 120 | ||||
| Polyfoam PVC-9, STU 14-07-41-64 | 2090 | 1290 | ||||
| Polyfoam PS-1-200 | 2050 | Substance or material | Specific output (consumption) of gases L i , kg kg -1 | |||
| L CO | LCO2 | L O2 | H HCl | |||
| Cotton | 0,0052 | 0,57 | 2,3 | - | ||
| Linen | 0,0039 | 0,36 | 1,83 | - | ||
| Cotton + nylon (3:1) | 0,012 | 1,045 | 3,55 | - | ||
| Turbine oil TP-22 | 0,122 | 0,7 | 0,282 | - | ||
| AVVG cables | 0,11 | - | - | 0,023 | ||
| APVG cables | 0,150 | - | - | 0,016 | ||
| Wood | 0,024 | 1,51 | 1,15 | - | ||
| Kerosene | 0,148 | 2,92 | 3,34 | - | ||
| Wood fire-retardant with SDF-552 | 0,12 | 1,96 | 1,42 | - | ||
BIBLIOGRAPHY
1. Roitman M. Ya. Fire safety regulation in construction. - M.: Stroyizdat, 1985. - 590 p.2. All-Union norms of technological design. : ONTP 24-86/Ministry of Internal Affairs of the USSR; Introduction 01/01/87: Replaced SN 463-74. - M.. 1987. - 25 p.
3. Conducting research and developing a manual to determine the necessary time for evacuating people from halls in case of fire: Report on research / VNIIPO of the USSR Ministry of Internal Affairs; Head T. G. Merkushkina. - P.28.D.024.84; No. GR 01840073434; Inv. No. 02860056271. - M.. 1984. - 195 p.
4. Methods of calculation temperature regime fire in the premises of buildings for various purposes: Recommendations. - M.: VNIIPO MVD USSR. 1988. - 56 p.
Material presented on the page NOT AN OFFICIAL EDITION
Forced evacuation has long attracted the attention of designers and firefighters. This is explained by the fact that fires still continue to be accompanied by human casualties. In connection with the construction of high-rise residential and public buildings, the desire to cooperate with public buildings in which significant masses of people are concentrated, the problems of the internal layout of buildings, taking into account the provision of safe evacuation of people, are becoming increasingly important.
The forced evacuation of people is considered successful if it can be completed within such a time that the harmful effects of the fire cannot have a negative effect on the human body. Therefore, the main criterion for evaluating design, planning and organizational decisions to ensure the safety of evacuation of people is its short duration.
The safety condition is considered fulfilled if the estimated duration of the forced evacuation is less than or equal to the allowable duration: τр≤τadd.
The movement of people out of buildings is consistent with the layout of these buildings. However, the rhythm and pace of movement depend not only on planning and design solutions, but also on the size of evacuation routes and exits. Therefore, in order to determine the compliance of the dimensions of evacuation routes and exits with safety requirements, the estimated evacuation time is determined by the length of the evacuation routes and by the capacity of the evacuation exits.
Typically, the calculations are exploratory in nature. Taking the planning project as a basis, they find the length of evacuation routes provided for by this project, the width of the aisles, and the number of evacuees. Then, according to these data, the estimated duration of the evacuation is determined and compared with the allowable value of the evacuation time. If the safety conditions are met, i.e. τр≤τadd, then it is considered that the dimensions of evacuation routes and exits, their number comply with fire safety requirements. Otherwise, changes are made to the layout of evacuation routes and evacuation exits and the calculation is repeated.
The calculation of the evacuation time is made according to the methodology set forth in the book by VF Kudalenkin “Fire Prevention in Construction” M.stroyizdat 1989 and GOST 12.1.004-91.
1. The permissible duration of the evacuation of people from a 2-storey canteen of the 2nd degree of fire resistance is determined by SNiP 21 01 97 * τadditional = 2.56 minutes.
2. On the layout plan of the dining room, the evacuation route for people is determined and divided into calculated sections.
3. The estimated time for the evacuation of people from the building is determined, in accordance with paragraph 6.15. SNiP 21-01-97 * “Fire safety of buildings and structures”, which states that when installing two evacuation exits, each of them must ensure the safe evacuation of all people in the premises.
Plot №1
Number of people N1=20 people.
The width of the track section δ1=1.8 m.
Section length l1=4.2 m.
On the initial sections of the path, the density of the human flow is determined:
D1=(N1´f)/(l1´δ1)=20´0.1/4.2´1.8=0.26 m²/m², where f=0.1 m² is the average area of a person’s horizontal projection.
According to table 2 GOST 12.1.004-91 “Fire safety”, the speed and intensity of the human flow is determined
υ1=60+(47-60)/(0.3-0.2)´(0.26-0.2)=52.2 m/min.
q1=12+(14.1-12)/(0.3-0.2)´(0.26-0.2)=13.26 m/min.
τ1=l1/υ1=4.2/52.2=0.08 min.
Plot #2
q2=q1´δ1/δ2=13.26´1.8/1.2=19.89 m/min.
Plot #3
Doorway width δ2=1.2 m.
The width of the track section δ3=1.8m.
Section length l3=1.8m.
q3=q2´δ2/δ3=19.89´1.2/1.8=13.26 m/min.
υ3=60+(47-60)/(0.3-0.2)´(0.26-0.2)=52.2 m/min.
τ3=l3/υ3=1.8/52.2=0.03 min.
Plot №4
The width of the track section δ4=1.2m.
The intensity of the human flow:
q4=q3´δ3/δ4=13.26´1.8/1.2=19.89 m/min.
Plot №5
The width of the track section δ5=1.2m.
Section length l5=7.2m.
The intensity of the human flow:
q5=19.89´1.2/1.2=19.89 m/min.
q5=19.89> qmax=16.5 therefore, according to clause 2.5 of GOST 12.1.004-91, we accept:
q5=13.5 m/min, at D=0.9 and more.
υ5=15 m/min
τ5=7.2/15=0.48 min.
Plot №6
The width of the track section δ6=1.2m.
The intensity of the human flow:
q6=13.5´1.2/1.2=13.5 m/min.
Plot No. 7
The width of the track section δ7=1.2m.
Section length l7=90m.
The intensity of the human flow:
q7=95+(68-95)´(13.5-9.5)/(13.6-9.5) =68.7 m/min.
τ7=l7/υ7=90/68.7=1.31 min.
Plot No. 8
The width of the track section δ8=1.2m.
Section length l8=8.4m.
q8=13.5 m/min.
τ8=l8/υ8=8.4/15=0.56 min.
Plot No. 9
The width of the track section δ9=3.6m.
Section length l9=6m.
q9 =13.5´1.2/3.6=4.5 m/min.
υ9=100 m/min.
τ9=l9/υ9=0.6 min.
Plot №10
Section length l10=1.2m.
q10=4.5´3.6/1.2=13.5 m/min.
Plot №11
The width of the track section δ11=3m.
Section length l11=3.5m.
q11=q10´δ10/δ11=13.5´1.2/3=5.4 m/min.
υ11=97.33 m/min.
τ11=l11/υ11 =0.04 min.
The evacuation time will be:
τ= τ1+τ3+τ5+τ7+τ8+ τ9+ τ11=0.08+0.03+0.48+1.31+0.56+0.06+0.04=2.56 min
The estimated time of evacuation of people in the 2-storey dining room is less than the permissible one, therefore, evacuation routes and exits meet the requirements of SNiP 21.01.97 * for residential buildings the first degree of fire resistance.
Technical solutions to eliminate identified shortcomings
1. Doors in fire barriers should be equipped with devices for self-closing.
2. Openings in fire barriers to fill wooden doors sheathed with metal on asbestos cement, with the appropriate fire resistance limits.
3. To prevent the spread of fire through air ducts, it is necessary to provide air ducts and shafts made of non-combustible materials with a fire resistance limit of 0.5 hours when air ducts pass through the floors.
4. Increase the fire resistance of stair stringers up to one hour by plastering.
5. Design and install an automatic fire alarm system.
6. Equip fire hydrants located on each floor of the stairwells.
TO THE COMMANDER OF THE MILITARY UNIT
INSTRUCTION
By me _ on the basis of _
In the presence of the representatives you selected, the organization and condition of the fire protection of the military unit _ and the implementation of orders _ were checked
Comparing this interval with estimated (actual) evacuation time, make a conclusion about ensuring / not ensuring the safe evacuation of people.
Calculation of people is a mandatory calculation as part of Section No. 9 "Measures to ensure fire safety" of the project documentation (Article 53, Federal Law No. 123).
In accordance with Federal Law No. 123-FZ "Technical Regulations on Fire Safety Requirements" (Article 53), the safe evacuation of people must be ensured at the protected facility.
Modern construction has one distinctive feature - an increase in the number of buildings with a mass stay of people.
These include multifunctional complexes, cinemas, clubs, supermarkets, industrial buildings, etc.
Fires in such premises are often accompanied by injury and death of people. First of all, this applies to rapidly developing fires that pose a real danger to humans within a few minutes after their occurrence and are characterized by an intense impact on people. fire hazards(Further OFP). The most reliable way to ensure the safety of people in such conditions is the timely evacuation of the premises in which the fire broke out.
Each object must have such a space-planning and technical design so that the evacuation of people from the premises is completed until reaching OFP maximum allowable values. In this regard, the number, dimensions and design of evacuation routes and exits are determined depending on required evacuation time.
Data for required evacuation time are the initial information for calculating the level of safety of people in case of fires in buildings.
Wrong definition required evacuation time may lead to incorrect design decisions and increase the cost of buildings or to insufficient safety of people in the event of a fire.
Required evacuation time is calculated as the product of the critical duration of a fire for a person and the safety factor.
Under critical fire duration means the time after which a dangerous situation arises due to the achievement of one of the OFP maximum permissible value for a person.
To the number fire hazard factors (HPF) that pose the greatest danger to people indoors in the initial period of a fire include:
elevated ambient temperature;
smoke leading to loss of visibility;
more toxic combustion products;
reduced oxygen concentration.
Calculation of the required evacuation time
The calculation of the evacuation time in case of fire is carried out in several stages:
I. Collection of baseline data
Calculation tasks are defined:
- evacuation possibilities of the building;
- Guaranteeing the safety of the movement of people.
II. Determination of the geometric characteristics of the room
A geometric measurement of exit routes is carried out, and the parameters of the movement of persons in the danger zone are calculated.
III. The choice of design schemes for the development of a fire
Determination of the critical duration of a fire for the chosen scheme of its development.
I.Y. Determining the most dangerous scheme for the development of a fire in a room
- Produced calculation of the required evacuation time.
- Risk assessment during evacuation and determination of the need for any additional fire protection equipment.
Estimated evacuation time
analytical model (the calculation is made manually, designed for small buildings, structures and structures that do not have security zones and people with limited mobility);
mathematical model of individual flow movement of people (calculation is made using a software package, for buildings with security zones and the presence of people with limited mobility);
mathematical model simulating-stochastic movement of people (the calculation is made using a software package, for buildings of complex architecture, with the presence of security zones and the presence of people with limited mobility).
Required evacuation time in case of fire defined in one of the following ways:
integral method (for premises with a simple geometric shape, it is also used for preliminary calculation in order to identify the most dangerous variant of the development of a fire);
zone (zonal) method (for buildings with a developed vertical and horizontal system of premises, a simple form);
field method (for any building structures with any layout, it is recommended for rooms in which one of the geometric dimensions is 5 or more times larger than any other).
The specialists of our design company have extensive experience in performing work to determine the conditions for the safe evacuation of people in case of fire, which includes determination of estimated evacuation time, determination of the required evacuation time.
All documents presented in the catalog are not their official publication and are intended for informational purposes only. Electronic copies of these documents can be distributed without any restrictions. You can post information from this site on any other site.
USSR MINISTRY OF INTERNAL AFFAIRS
ALL-UNION ORDER “Badge of Honor”
RESEARCH INSTITUTE
FIRE DEFENSE.
APPROVE
Head of VNIIPO of the Ministry of Internal Affairs of the USSR
D. I. Yurchenko
September 29, 1989
CALCULATION OF NECESSARY TIME
EVACUATION OF PEOPLE FROM PREMISES
IN THE FIRE
MOSCOW 1989
Calculation of the necessary time for the evacuation of people from premises in case of fire: Recommendations. - M.: VNIIPO MVD USSR, 1989.
The procedure for calculating the required time, the evacuation of people from premises for various purposes in the event of a fire in them, is outlined.
When solving the problem, the following dangerous fire factors were taken into account: elevated ambient temperature; smoke leading to loss of visibility; toxic gases; reduced oxygen concentration. The determination of the required evacuation time was carried out under the condition that one of these factors reached the maximum permissible value for a person.
Designed for engineering and technical workers of the fire department, teachers, students of fire-technical educational institutions, employees of research, design, construction organizations, etc. institutions.
Tab. 4, appendix 1, bibliography: 4 titles.
INTRODUCTION
A characteristic feature of modern construction is an increase in the number of buildings with a mass stay of people. These include indoor cultural and sports complexes, cinemas, clubs, shops, industrial buildings, etc. Fires in such premises are often accompanied by injury and death of people. First of all, this applies to fast-growing fires, which pose a real danger to humans within a few minutes after their occurrence and are characterized by an intense impact on people of dangerous fire factors (MF). The most reliable way to ensure the safety of people in such conditions is the timely evacuation of the premises in which the fire broke out.
In accordance with GOST 12.1.004-85. SSBT. "Fire safety. General requirements", each object must have such a space-planning and technical design so that the evacuation of people from the premises is completed before the maximum permissible values are reached. In this regard, the number, dimensions and design of evacuation routes and exits are determined depending on the required evacuation time, i.e. the time during which people must leave the premises without being exposed to a fire that is dangerous to life and health / /. Data on the required evacuation time is also the initial information for calculating the level of safety of people in case of fires in buildings. Incorrect determination of the required evacuation time can lead to incorrect design decisions and an increase in the cost of buildings or to insufficient protection of people in the event of a fire.
In accordance with the recommendations of the work / /, the required evacuation time is calculated as the product of the critical fire duration for a person and the safety factor. The critical duration of a fire means the time after which a dangerous situation arises due to the achievement of one of the OFPs of the maximum permissible value for a person. At the same time, it is assumed that each hazardous factor affects a person independently of the others, since the complex impact of various qualitative and quantitative combinations of MFs that change over time, characteristic of the initial period of fire development, is currently not possible to assess. The safety factor takes into account the possible error in solving the problem. It is taken equal to 0.8 / /.
Thus, to determine the required time for evacuating people from the premises, it is necessary to know the dynamics of the magnetic field in the area where people stay (working area) and the maximum allowable values for a person for each of them. Among the OFP, which pose the greatest danger to people indoors in the initial period of a rapidly developing fire, can be attributed: elevated ambient temperature; smoke leading to loss of visibility; more toxic combustion products; reduced oxygen concentration.
The method for calculating the required evacuation time, set out in these recommendations, was developed on the basis of theoretical and experimental studies of the dynamics of the RPP, carried out at the VNIIPO of the Ministry of Internal Affairs of the USSR, acting at the critical stage of a fire for a person in premises for various purposes. As the maximum permissible levels of RPP for people, the values obtained as a result of biomedical studies of the impact on humans of various hazardous factors were used.
1. GENERAL PROVISIONS
through open openings, only the displacement of gas from the room occurs;
the absolute pressure of the gas in the room during a fire does not change;
the ratio of heat loss in building structures to the heat power of the fire source is constant in time;
the properties of the environment and the specific characteristics of the material burning during a fire (lower working calorific value, smoke-generating ability, specific output of toxic gases, etc.) are constant;
the dependence of the burnt mass of material on time is a power function.
The proposed method is applicable for calculating the required evacuation time in case of rapidly developing fires in rooms with an average rate of increase in the ambient temperature over the period under consideration of more than 30 deg·min -1 . Such fires are characterized by the presence of near-wall circulation jets and the absence of a clear boundary of the smoke layer. The use of calculation formulas for fires with a lower temperature growth rate will lead to an underestimation of the required evacuation time, i.e. to increase the margin of safety in solving the problem.
2. METHODOLOGY FOR CALCULATION OF THE NECESSARY TIME TO EVACUATE PEOPLE FROM PREMISES IN THE FIRE
2.1. General calculation procedure
Based on the analysis of the design solution of the object, the geometric dimensions of the room and the height of the working areas are determined. The free volume of the room is calculated, which is equal to the difference between the geometric volume of the room and the volume of equipment or objects inside. If it is impossible to calculate the free volume, then it is allowed to take it equal to 80% of the geometric volume / /.
Next, design schemes for the development of a fire are selected, which are characterized by the type of combustible substance or material and the direction of possible flame propagation. When choosing design schemes for the development of a fire, one should focus primarily on the presence of flammable and combustible substances and materials, the rapid and intense burning of which cannot be eliminated by the forces of people in the room. Such substances and materials include: flammable and combustible liquids, loose fibrous materials (cotton, linen, fumes, etc.), hanging fabrics (for example, curtains in theaters or cinemas), scenery in entertainment enterprises, paper, wood shavings, some types of polymeric materials (for example, soft polyurethane foam, plexiglass), etc.
For each of the selected fire development schemes, the critical duration of a fire for a person is calculated according to the following factors: elevated temperature; loss of visibility in smoke; toxic gases; reduced oxygen content. The obtained values are compared with each other and the minimum is selected from them, which is the critical duration of the fire. no j -th calculation scheme.
Then the most dangerous scheme for the development of a fire in a given room is determined. For this purpose, for each of the schemes, the amount of material burned out by the time , is calculated m j and compared with c the total amount of this material M j , which can be covered by fire according to the considered scheme. Design schemes, in which m j >M j are excluded from further analysis. From the remaining design schemes, the most dangerous fire development scheme is selected, in which the critical fire duration is minimal.
Learned valuetkris taken as the critical fire duration for the space under consideration.
By value tkrthe necessary time for the evacuation of people from this room is determined.
2.1.1. Determination of the geometric characteristics of the room
The geometric characteristics of the room used in the calculation include its geometric volume, the reduced height H and the height of each of the working areas h .
The geometric volume is determined based on the size and configuration of the room. The reduced height is found as the ratio of the geometric volume to the area of the horizontal projection of the room. The height of the working area is calculated as follows:
where h is - height of the mark of the zone where people are above the floor of the room, m; δ - the difference in floor heights, equal to zero with its horizontal location, m.
It should be borne in mind that people who are at a higher level are exposed to the maximum danger in a fire. So, when determining the necessary time for the evacuation of people from the stalls of the auditorium with an inclined floor, the value h for the stalls, you need to calculate, focusing on the rows of seats that are remote from the stage (located at the highest elevation).
2.1.2. The choice of design schemes for the development of a fire
The time of occurrence of situations dangerous to humans during a fire in a room depends on the type of combustible substances and materials and the burning area, which, in turn, is determined by the properties of the materials themselves, as well as the way they are laid and resolved. Each calculation scheme for the development of a fire in a room is characterized by the values of two parameters A and n , which depend on the shape of the combustion surface, the characteristics of combustible substances and materials and are determined as follows.
1. For burning flammable and combustible liquids spilled on the area F :
when burning a liquid at a steady rate (typical for volatile liquids)
where ψ is the specific steady-state mass burnout rate of the liquid, kg·m -2 s -1 ;
when burning a liquid at an unsteady speed
The critical duration of a fire is determined for a given design scheme
,
where i = 1, 2, ... n - index of toxic combustion product.
In the absence of special requirements, the valuesα and E taken equal to 0.3 and 50 lux, respectively.
2.1.4. Determining the most dangerous scheme for the development of a fire in a room
After calculating the critical duration of a fire for each of the selected schemes of its development, the amount of burnt out by the timetkrj material .
Each value in the considered j -th scheme is compared with the indicator Mj . Design schemes, in which m j >M j , as already noted, are excluded from further consideration. Of the remaining design schemes, the most dangerous one is selected, i.e. the one for which the critical duration is minimal t cr = min ( t cr j ).
Received value t cr is the critical fire duration for a given work area in the space under consideration.
2.1.5. Determining the required evacuation time
The required time for the evacuation of people from a given working area of the premises under consideration is calculated by the formula:
,
where to b- safety factor, to b = 0,8.
Initial data for calculations can be taken from Table. - applications or from reference literature.
2.2. Calculation examples
Example 1Determine the necessary time for the evacuation of people from the auditorium of the cinema. The length of the hall is 25 m, the width is 20 m. The height of the hall from the side of the stage is 12 m, from the opposite side - 9 m. The length of the horizontal section of the butt near the stage at the zero level is 7 m. marks. Curtain weighing 50 kg is made of fabric with the following characteristics:Q= 13.8 MJ kg -1; D\u003d 50 Np m 2 kg -1; L O 2 , = 1.03 kg·kg -1 ; L CO2 \u003d 0.203 kg kg -1; L CO \u003d 0.0022 kg kg -1; ψ \u003d 0.0115 kg m 2 s -1;V B= 0.3 m s -1 ; VG= 0.013 m s -1 . The upholstery of the chairs is polyurethane foam covered with leatherette. The initial temperature in the hall is 25 °C, the initial illumination is 40 lx, the volume of items and equipment is 200 m 3 .
1. We determine the geometric characteristics of the room.
The geometric volume is
.
Reduced Height H is defined as the ratio of the geometric volume to the area of the horizontal projection of the room
.
The room contains two working areas: parterre and balcony. In accordance with the instructions given in section (), we find the height of each working area
for parterre h \u003d 3 + 1.7 - 0.5 - 3 \u003d 3.2 m;
for balcony h \u003d 7 + 1.7 - 0.5 - 3 \u003d 7.2 m.
The free volume of the room V \u003d 5460 - 200 \u003d 5260 m 3.
2. We select the design schemes of the fire. In principle, two options for the occurrence and spread of a fire in a given room are possible: along the curtain and along the rows of seats. However, the ignition of the leatherette upholstery of the chair from a low-calorie source is difficult to implement and can be easily eliminated by the forces of the people in the hall.
Consequently, the second scheme is practically unrealistic and disappears.
Specific mass burnout rate ψ×10 3 , kg m 2 s -1
Net calorific value Q, kJ kg -1
Petrol
61,7
41870
Acetone
44,0
28890
diethyl ether
60,0
33500
Benzene
73,3
38520
Diesel fuel
42,0
48870
Kerosene
48,3
43540
fuel oil
34,7
39770
Oil
28,3
41870
Ethanol
33,0
27200
Turbine oil (TP-22)
30,0
41870
Isopropyl alcohol
31,3
30145
Isopentane
10,3
45220
Toluene
48,3
41030
sodium metal
17,5
10900
Wood (bars) W = 13.7%
39,3
13800
Wood (furniture in residential and office buildings W = 8-10%)
14,0
13800
paper loosened
8,0
13400
Paper (books, magazines)
4,2
13400
Books on wooden shelves
16,7
13400
Film triacetate
9,0
18800
Carbolite products
9,5
26900
Rubber SCS
13,0
43890
Natural rubber
19,0
44725
Organic glass
16,1
27670
Polystyrene
14,4
39000
Rubber
11,2
33520
Textolite
6,7
20900
polyurethane foam
2,8
24300
Staple fiber
6,7
13800
Staple fiber in bales 40×40×40 cm
2,5
13800
Polyethylene
10,3
47140
Polypropylene
14,5
45670
Cotton in bales ρ = 190 kg m -3
2,4
16750
Cotton loosened
21,3
15700
Flax loosened
21,3
15700
Cotton + nylon (3:1)
12,5
16200
Table 2
Linear velocity of flame propagation over the surface of materials
|
materials |
Average linear velocity of flame propagation V×10 2 , m s -1 |
|
Wastes of textile production in a loosened state |
10,0 |
|
Cord |
1,7 |
|
Cotton loosened |
4,2 |
|
Flax loosened |
5,0 |
|
Cotton + nylon (3:1) |
2,8 |
|
Wood in stacks at different humidity, in% |
|
|
8-12 |
6,7 |
|
16-18 |
3,8 |
|
18-20 |
2,7 |
|
20-30 |
2,0 |
|
over 30 |
1,7 |
|
Hanging fleecy fabrics |
6,7-10 |
|
Textiles in a closed warehouse with a load of 100 kg m -2 |
0,6 |
|
Paper in rolls in a closed warehouse when unloading 140 kg m -2 |
0,5 |
|
Synthetic rubber in a closed warehouse with a load of more than 290 kg m -2 |
0,7 |
|
Large area wooden flooring, wooden walls and fibreboard walls |
2,8-5,3 |
|
Straw and reed products |
6,7 |
|
Fabrics (canvas, baize, calico): |
|
|
horizontally |
1,3 |
|
in the vertical direction |
30 |
|
in the normal direction to the surface of the tissues with a distance between them of 0.2 m |
4,0 |
Table 3
Smoke generating capacity of substances and materials
|
Substances and materials |
Smoke generating capacity D, Np m 2 kg -1 |
|
|
Smoldering |
Combustion |
|
|
Butyl alcohol |
80 |
|
|
Gasoline A-76 |
256 |
|
|
ethyl acetate |
330 |
|
|
Cyclohexane |
470 |
|
|
Toluene |
562 |
|
|
Diesel fuel |
620 |
|
|
Wood |
345 |
23 |
|
Wood fiber (birch, aspen) |
323 |
104 |
|
Chipboard, GOST 10632-77 |
760 |
90 |
|
Plywood, GOST 3916-65 |
700 |
140 |
|
Pine |
759 |
145 |
|
Birch |
756 |
160 |
|
Fibreboard (Fibreboard) |
879 |
130 |
|
PVC linoleum, TU 21-29-76-79 |
200 |
270 |
|
Fiberglass, TU 6-11-10-62-81 |
640 |
340 |
|
Polyethylene, GOST 16337-70 |
1290 |
890 |
|
Tobacco "Jubilee" 1 grade, rl. thirteen % |
240 |
120 |
|
Polyfoam PVC-9, STU 14-07-41-64 |
2090 |
1290 |
|
Polyfoam PS-1-200 |
2050 |
1000 |
|
Rubber, TU 38-5-12-06-68 |
1680 |
850 |
|
High pressure polyethylene (PEVF) |
1930 |
790 |
|
PVC film grade PDO-15 |
640 |
400 |
|
Film brand PDSO-12 |
820 |
470 |
|
turbine oil |
243 |
|
|
Flax loosened |
3,37 |
|
|
Viscose fabric |
63 |
63 |
|
Atlas decorative |
32 |
32 |
|
Reps |
50 |
50 |
|
Woolen furniture fabric |
103 |
116 |
|
Canvas tent |
57 |
58 |
Table 4
Specific output (consumption) of gases during combustion of substances and materials
Cotton + nylon (3:1)
0,012
1,045
3,55
Turbine oil TP-22
0,122
0,7
0,282
AVVG cables
0,11
0,023
APVG cables
0,150
2. All-Union norms of technological design. Definition of categories of premises and buildings for explosion and fire hazard: ONTP 24-86 / Ministry of Internal Affairs of the USSR; Introduction 01/01/87: Replaced SN 463-74. - M.. 1987. - 25 p.
3. Conducting research and developing a manual to determine the necessary time for evacuating people from halls in case of fire: Report on research / VNIIPO of the USSR Ministry of Internal Affairs; Head T. G. Merkushkina. - P.28.D.024.84; No. GR 01840073434; Inv. No. 02860056271. - M.. 1984. - 195 p.
4. Methods for calculating the temperature regime of a fire in the premises of buildings for various purposes: Recommendations. - M.: VNIIPO MVD USSR. 1988. - 56 p.
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