【 Weak current College 】 on advanced IRC air conditioning fire and smoke exhaust system design

Abstract: the sports building clustered, size, space, once there is a fire burning objects will produce a temperature high of toxic and flammable gas flow around, triggering instant deflagration, evacuation and rescue difficulties, poisoning, asphyxia, injuries, causes great losses. Therefore, the stadium fire protection and ventilation air conditioning smoke control system design, is the relationship to life and property safety of major issues that should never be taken lightly. In the sports building fire and smoke exhaust system design in order to prevent and reduce fire hazards, the protection of national property and security of the person, require the physical architecture to enhance the design of fire smoke exhaust is of great practical significance of the economy.
Keywords: exhausting positive pressure air exhaust volume
I. Design introduction
Modern advanced sports building, international sports, Olympic and Asian Games, the games of the world famous race of positive encouragement, like mushrooms, sports and recreation, the city's rapid rise in Germany, the world of sports building sports buildings clustered, size, space, once there is a fire burning objects will produce a temperature high of toxic and flammable gas flow around, triggering instant deflagration, evacuation and rescue difficulties, poisoning, asphyxia, injuries, causes great losses. Therefore, the stadium fire protection and ventilation air conditioning smoke control system design, is the relationship to life and property safety of major issues that should never be taken lightly. In the sports building fire and smoke exhaust system design in order to prevent and reduce fire hazards, the protection of national property and security of the person, require the physical architecture to enhance the design of fire smoke exhaust is of great practical significance of the economy.
Now new fire prevention code GB0045-95 mandatory national standards since 1995 year, 11 1 January. So how to conscientiously implement the new doctrine of "good," as the combination "againstdisappears the design gems, the accidents occurring in the first place, who destroy stability it needs to research, science and looking for a way to have physical architectural features, you must take full account of fire safety, ventilation, air conditioning system of their own safety and guarantee the evacuation and fire suppression of smoke quickly.
Second, advanced sports the importance of building fire smoke
1. physical characteristics analysis of building fire: modern sports building, electrical equipment, lines, ventilation and air conditioning pipe extending in all directions, are caused by fire spread, whether it is a multifunctional Sports Centre, swimming pool, Indoor skating rink or or ice hockey rink, in the event of fire, in the competition Hall, flame center vertical upward flow, to 4 ~ 6m/s spread to the ceiling and roof truss, when the various shaft, such as the fresh air, exhaust, rushed, air and water wells, staircases and elevator shaft and so have become the big chimney fire flee. Because of the chimney effect heat pressure caused by the rapid expansion of the Fireworks, or even through the rapid dissemination of expansion joints, when the fire burning to 6 minutes, the flame temperature will rise to more than 900 ° c, due to the fire burning and baking, and so on, the steel roof strength reduction, the large space fire General in 15 minutes or so steel roof truss will fall down, at which point the Hall smoke MI vines, fire raging, inexorable panic-stricken audience, chaos, acute phase displacement will result in significant casualties and severe economic losses.
2. analysis of the causes of fires: basis for domestic and foreign advanced sports building fire reasons: (1) most of which were due to electrical equipment and wiring out of repair, electrical insulation ageing, long power overheating caused by fire; (2) fluorescent lamp circuit connection not dense, bad, high thermal burns fire causing fire; (3) electrical wiring connector copper wire oxidation, bad resistance is too large, high fever, the combustion of fire; (4) because of the throw cigarette ignited combustible or trash fire; (5) because of the open fire ignited electrical construction air duct insulation and fire; (6) there are other stable short causes fire accident. Due to the large space buildings fire suppression is difficult, resulting in financial losses, is very substantial.
3, sports buildings fire loss instances: (1) a County Coliseum on 1973 in case of fire, the fire burning for 5 hours to make this more than a large stadium seat burnt, losses, losses, and later had to rebuild; (2) a city Stadium in subsidiary rooms connected in 1974 in case of fire, according to the analysis because of the wire insulation ageing touch two lines together cause short circuit, fire, alarm occurs late in the night, fire brigade arrived at the scene, the flame has been in and out of the roof to cause hundreds of square meters of buildings burnt losses; (3) British for Bradford City outdoor Stadium grandstand in 1985, the fire, was a football game, 12000 audience, fire is lit as the cigarette, caused by garbage burning flame 1 minutes later, the fire will reach the roof of the behind the grandstand, the flame was extended to the following fuel heat radiation, causing the following stand flame rapidly to the horizontal direction, causing the roof structure is burning, the fire burn 7 hours, seating and bleachers burnt. Be smoke burnt to death and Hoon died audience up to 52 people and injured more than 200 people, a United Kingdom, the British Prime Minister to speak on television, you should learn the lessons of the grave. From the above example, the visible fire intensively modern sports building of smoke control how important design is.
Third, the sports building ventilation, air conditioning fire and smoke exhaust technology
Modern sports building ventilation and air conditioning pipelines Criss, distribution to each section, if handled well, the network becomes a bunch of big chimney fire, so you must have a reliable fire safety measures for the prevention of them.
1, ventilation, air conditioning, cooling machine room and computer room of the central computer management in control rooms, energy control centres should be equipped with automatic alarm control and measuring apparatus, central control room also has automatic fire-extinguishing appliances;
2, air duct, cold (heat) pipes of heating and insulation devices are non-burning material applied;
3, duct and accessories (such as wind and valves, etc.) apply non-burning material, air conditioning system generally do not double as fire smoke exhaust system, if you really must use either, you should have safety canBy automatically switching valve, general ventilation system doubles as a fire at the time of the exhaust system, the air ducts, piping and equipment shall meet the requirements of the exhaust system;
4, ventilation, air conditioner should be independent room with firewall fire panels and other room, engine room and the adjoining corridors or room doors should be a class a fire door;
5, ventilation and air conditioning system with fan or air conditioner made of non-combustible material products, plastic and glass fiber reinforced plastic fan should not be used for air conditioning;
6, to contain the flue gas has flowed into, the spread of fire, ventilation and air-conditioning system air supply pipes, ventilation or air supply pipe in passing through the firewall, fire floor should be installed for fire dampers. At the same time air duct should not pass through the firewall and deformational slots, if you must travel through the crossing set fire dampers, vertical total wind pipes and each floor level horizontal pipe junction should also be set on fire dampers, and fire safety valve connection of wind pipes in andrographis firewall or fireproof floor Office application ≥ 2mm thick steel plate production;
7. in connection with air conditioner and ventilation duct fire on the valve closes the valve should be set, i.e. fire signal chain control valve is closed to linkage blowers and back to fan stops; fire damper installation should set up separate hanging bracket to prevent wind pipe deformation affecting fire safety valve closed tightness and set on fire by 450 × 450mm inspection hole;
8, muffler, muffler elbow of insulation should be non-burning material, application of anechoic timber also design of anechoic materials;
9, all ventilation, air conditioning and refrigeration equipment, the power shall be and the sports building auto-alarm fire extinguishing system associated locks, once a fire, ventilation, air conditioning and refrigeration appliances devices should immediately cut off and stop running.
IV. positive pressure air and exhaust gas volume calculation of simple quick optimization
1. positive pressure ventilation system air supply fast optimization calculation method:
Positive pressure ventilation system is designed to fire after guarantee sports buildings are safe and reliable evacuation channels, to accomplish the rapid evacuation of people's security and to ensure that firefighters can secure the rapid adoption, to fight the fire as soon as possible; ensure the stairwells, Elevator, front room and combined with former room and corridor between certain positive pressure value, so external intrusion, smoke does not guarantee that each have sufficient fresh air and keep the stairway has high visibility and clear light, ensure that the fire occurred when there is a reliable security evacuation channels. In the actual calculation method used by according to incomplete statistics, there are dozens of large, can be summarized as the pressure difference, difference of wind speed, floors are air law and comprehensive calculation of four, but this one should take the pressure difference and the door fast optimization of wind speed is the most practical. Therefore, the Fire Department of China Academy of determination: positive pressure points, negative pressure values system xun experimental study, is the author of two methods, the experimental results confirmed the pressure difference is more than difficult door wind speed method, but pressure difference than door wind speed of more accurate and realistic, the pressure difference calculation method and door wind speed method describes as follows:
(1) pressure difference calculation method: basic formula is:
L=aF[（2ΔP/P）1/2]×3600（m3/h）-（1）
Type: Δ P-pressure difference on both sides of the door;
A-the general flow coefficient, a = 0.6 ~ 0.7, usually take 0.65;
P-the density of the gas through the door (take air density), take to the air 20 ℃ 1.2 (Kg/m3);
F-open circulation area (m2);
Formula (1), for the entire building each floor door side pressure difference, air leakage through the door of the total amount that can be simplified to:
L=0.827A·ΔP1/2×3600（m3/h）… (2)
Type: A-front rooms on each floor or staircase door gaps in circulation area (m2);
Δ P-front room side pressure (Pa);
0.327-integrated coefficient for a [(2/P) 1/2] specific numerical, equivalent to p = 1.2 (Kg/m3). In the calculation of the air, but also the air reserve coefficient β, β of 1.2 ~ General 1.1.
(2) door wind speed method: air through the door of the average velocity value, the calculation of the amount of air through a door is:
L=mF·V×3600（m3/h）… (3)
Type: m-storey building at the door;
F-door openings in the calculation of the circulation area (m2);
V-to door air flow average speed (m/s).
Using the formula (3) to calculate the amount of wind, the method is simple and convenient, because in the event of a fire, the doors are always open, the door wind speed of meaningful, therefore, has been widely used.
Advanced sports building smoke staircase and vestibule, combined with front room and fire the elevator (including handicapped lift) front room of mechanical compression air should be determined by calculation or by table 1 ~ determined in table 3:
Table 1 smoke staircase of pressurized air supply system burden before room floors without air pressure air front room air distribution of pressurized air memo
≪ 20 layer 25000 ~ 30000m3/h smoke staircase combined front room
16000~2000m3/h12000~16000m3/h
Table 2 fire service lift the burden of pressure air system pressurized air layer number memo
≪ 20 layer 15000 ~ 20000m3/h
Table 3 smoke staircase with natural gas, plus the former room or room does not have the natural smoke exhaust air system burden layers before before room or shared room of pressurized air notes I.
≪ 20 layer 22000 ~ 27000m3/h
2. sports building game lobby exhaust of a simple calculation method:
Smoke is relying on the consumption of electricity by the exhaust fan, will contest Hall of smoke from a steel grid structure roof flows into the extracted from the Auditorium and upper outdoors or spare row to smoke outdoors, is in the event of fire, make sure that the evacuation time and evacuation channel secure a rowSmoke, its calculation method of smoke may be new to the regulations on the requirements for Atrium, Atrium volume <17000m3时,其排烟量按其体积的6次/h换气计算,中庭的体积> 17000m3/h, the exhaust gas volume, depending on the volume of 4 times, but/h breathing a minimum exhaust gas volume should not be less than 102000m3/h.
3. sports building other room exhaust volume calculations:
(1) where the conditions set out the window, and can be opened in the window area > room area with 1/5 →, consider natural smoke;
(2) more than 100m3, and often someone stay or fuel more windowless room and basement room, smoke extraction facilities should be considered, the amount of smoke to assume a smoke partition: smoke or clear height > 6.00 m not designated smoke partition rooms should be not less than 60m3/h · m2 for calculation (single Typhoon machine minimum exhaust volume ≮ 7200m3/h). With two or more smoke partitions when you smoke should be maximum preventing smoke partition ≮ 120m3/h · m2.
(3) no direct daylight and natural ventilation, and more than 20 metres in the corridor or has direct daylight and natural ventilation, but longer than 60 metres of corridors should be designed exhaust facilities. Because no one room on fire, and smoke are channeling into the corridor, and staff must pass corridor to evacuation, according to the measured scene of a fire, the smoke bow cover the movement of nasal maximum distance can only 20 ~ 30 meters, so the sports building fire safety design should consider the problem of exhausting. corridor
V. sports building game lobby best exhaust method
Modern sports facilities for the construction of fire smoke, in addition to setting up automatic alarm sprinkler system and fire safety induction lamps and exit signs, take effective measures of smoke is very necessary. Therefore, it is recommended that the National Ministry of organization departments sports building experimental study on smoke control way, and for the future development of the sports building design fire protection standard. According to the domestic and foreign information and engineering survey, the game actually Hall of exhaust methods can be classified natural smoke and smoke exhaust two categories;
1, natural smoke: Natural smoke is located in the game lobby located at the top of the window (or exhaust port) or side wall of the high window exhaust. Its exhaust mechanism is to use fire heat, hot pressing the flue gas directly from the opening to the outside, this natural advantages are many flue way, no power no fan, one investment costs less, in the absence of power also double as ventilation.
However, due to natural smoke effect by smoke and hot pressing and buoyancy to guarantee, if for some reason the flue gas is cooling loss of buoyancy, the flue gas is completely lost the ability to exhaust-outdoor, natural smoke can only be used as a fire at the secondary role. Due to the impact on the natural smoke effects in a number of factors, it is the doctrine of law in China on sports building contest Hall of natural smoke extraction area is not for specific requirements. But Japan building regulations section 35 specifically building area > 500 square metres of stadiums, skating rink, swimming pool, training, and so you must set the smoke extraction facilities;
(1) Japan Technical Center to match the highest fortification at the top of the Hall surrounded by opening the window of the exhaust outlet, each exhaust port area of 0.7 square meters, a total of 42 total exhaust port area of 29.4 square meters;
(2) if the Beijing workers ' Stadium, in the competition Hall of the highest parts of the body, with a week of exhaust window, usually as the heat in the upper part of the Hall and the Hall dirty air, fire has played the role of natural gas;
(3) Shanghai Stadium in the competition Hall Center top margin to 33.5 metres can be opened with transom and side window can be opened fire, smoke, usually to make natural gas or exclude Auditorium and upper smoke to improve the freshness of the air in the Hall;
(4) Pakistan Stadium, in the middle of the Hall is equipped with eight top barrel air cap, diameter 1000mm. Usually use heat pressure, the ceiling of the heat and waste gas flows into the rooms, the total exhaust volume to 4000m3/h, fires can be as flue gas.
2. mechanical smoke extraction methods: our Government has always attached great importance to the physical construction of fire and smoke control technology in the doctrine of "GB50045-95 in the sports building fire resistance class 1, grade 2. Also provides for the physical architecture and other buildings of the fire separation. Auditorium security number of exports should not be less than 2, and each security export number not more than average evacuation 400 ~ 700 people. And request design indoor fire water and hydrant. In addition, more than 4000 seats in the upper part of the ceiling tiyuguanguanzhongting, VIP rooms, equipment rooms, players lounge and so should be set close automatic sprinkler and fire alarm facilities. Also provides for no conditions or natural smoke exhaust over 12 m in height should be set in the atrium of smoke. Special power supply must be equipped with fire protection and high-temperature exhaust fan, can adopt centrifugal fan or exhaust axial fans, and should be in the engine room entrance equipped with when the gas temperature of more than 280 ° c will automatically close when the smoke fire dampers. Exhaust fan should guarantee in 280 ° c can work continuously for 30 minutes. Exhaust fan of full pressure should be the most negative loop exhaust system, the exhaust gas volume should be increased air leakage coefficient (generally take 1.1 ~ 1.3).
When using mechanical centralized exhaust, the exhaust vents, exhaust air and flue gas discharge shall consider the issue, and resistant to high temperature flue gas discharge to stay away from nearby buildings, in order to avoid the spread of a fire outdoors.
3. exhaust outlet should be located in the ceiling or wall near the ceiling. Located in the ceiling of the exhaust outlet from the combustible components or fuel distance should not be less than 1.00 m. Exhaust vents should be turned off in peacetime, and should be equipped with manual and automatic opening device. Smoke exhaust port within the partition from the farthest point of horizontal distance shall not exceed 30 m. In the exhaust pipes should be provided when the gas temperature of more than 280 ° c, could itself off smoke fire dampers.
Mechanical smoke extraction system, when any of the exhaust vents or exhaust valve is opened, its rowFlue fan should be able to start.
For example: Beijing's gymnasium, 5000 more viewers, the game lobby with mechanical smoke extraction, in the lobby of the steel grid structure, setting four sets of fire smoke extraction system, the network has multiple exhaust outlets uniform layout, use the horizontal wind pipe and exhaust fan, from the roof of the side wall of efflux-outdoor, usually as a Hall ventilation, indoor air out of the foul line to outdoor, indoor air can maintain fresh, each system in the exhaust volume to total 1059m3/h, the exhaust is: 43800m3/h, a fire can exclude the grid, in the flue gas exhaust fan in each set are installed at the entrance of the flue gas temperatures up to 280 ° c can be self-closing fire control valve.
6. positive pressure air supply exhaust pipe and the system principle of material selection
(1) steel plate thickness can be general requirements for the selection of air duct, but to guarantee its strength and stiffness without deformation, fall off, no leakage, installation to tight; (2) also consider the fire resistance rating, you can select by pipeline section, pipe diameter or distance-big edge in 450 ~ 1000mm, δ = 1.5mm, its large side than 1000mm, δ = 2mm; (3) positive pressure ventilation piping if placed non-burning tubes may not do thermal insulation, fire smoke exhaust pipe to pass through the crossing part partition using δ = 25 non-burning material for insulation of pipelines, travel across the firewall should have special reinforcement measures; on the vertical pipe shaft should be at intervals of 2 layers in the floor for non-burning material separated by fire; (4) and the fire damper connected duct in travel across the firewall or fire floor outside should be ≥ 2mm thick steel plate production; (5) in exceptional cases, if we must use non-metallic non-fuels, should ensure that strong, not easily damaged, smooth inner wall, no leakage, pipe cross-section according to wind speed v = 15 ~ 20m/s select calculation; (6) fire protection duct may also use non-combustible glass fibre reinforced plastic (plate thickness δ = 3 ~ 6mm) production.
7. engineering design example
1. Fujian gymnasium positive pressure ventilation and exhaust design example: this is a seat diameter φ 92 meters, construction area of 25104 square meters Park flying saucer-shaped multifunctional Sports Centre, the competition Hall 34.8 meters high, can accommodate visitors 7500 people seat, the staircase, the handicapped elevator and room, set mechanical pressure positive pressure ventilation system 5, each system selects with the ultra low noise CDT35-11 type No5.6C, air t = 15400m3/h, H = 213Pa axial fans one to maintain the stairwell pressure value 50Pa > room positive pressure value 25Pa > Gallery positive pressure value 8Pa.
Competition Hall mechanical smoke extraction system, in the Hall over 30.8 metres truss in mechanical smoke extraction system 8, selection of high temperature fire exhaust fan GYF-X-6ZS muffler-No6, eight evenly spaced across the truss, the amount of the total exhaust 116000m3/h > 102000m3./h ("the regulations"). Even under the ceiling decorated with more than one normally closed exhaust outlet from the fire control centre, in the event of fire, the fire by smoke for notifications, instructions, exhaust outlet Center and exhaust fan, fan in 280 ° c at 30 minutes continuous operation, the system has more than 280 ° c can be self-closing smoke fire dampers in the exit of high-temperature exhaust fan is fitted with check valve to prevent air flow.
2. United States Detroit sports hall, the exhibition centre can accommodate a fixed seat, temporary seating block 10000 3200, mechanical smoke extraction, in the competition Hall roof top, set the exhaust vents and centrifugal exhaust fan, the exhaust pipe from the roof of the side wall of the smoke exhaust to outdoor, usually as exhaust.
3. the training Hall of Fujian province sports training Hall with smoke, training hall construction area for 5792m3/h, the four corners of the roof trusses are located within the exhaust system 4, the amount of the total exhaust 58000m3/h. Training Hall in smoke stairs located a pressurization system, air flow for 15400m3/h. The underground garage freezing room, pump room; a diesel generator room, transformation and distribution technologies, such as the House, with a mechanical smoke extraction system, choose GYF-Z high-temperature exhaust fan each one, the amount of the total exhaust 85000m3/h, basement by the underground shaft leads to the outdoor, basement peacetime air supply system as fire wind system.
4. Moscow Olympic gymnasium, Auditorium, with seating-35000 mechanical smoke extraction, in the game lobby ceiling has many flue gas exhaust outlet, with a total capacity of 60000m3/h. In addition, in the Auditorium and upper ceiling is also equipped with mechanical ventilation system also doubles as a smoke, exhaust volume for 45000m3/h.
5. Canada-curtain's kamc Hall is a include ice, function room, can accommodate visitors who match 18000 Hall corners each have a set of exhaust system, the exhaust vents, exhaust duct and exhaust fan is located within the roof steel grid structure, in order to avoid the emission of smoke affect adjacent buildings, in the game lobby outside corner office has a smoke exhaust shaft. Every set amount of exhaust smoke exhaust system as 80000m3/h, total exhaust volume 320000m3/h. F>N3GPR l
6. in the senior civil sports building fire engineering should also pay particular attention to the following:
(1) the game lobby and ancillary buildings should be located between the fire doors and firewall, the security entrance door should outwards;
(2) design wind pipe and frozen water pipes must be made of non-combustible materials and thermal insulation;
(3) should be in the game lobby roof set up automatic sprinkler fire-fighting equipment and mechanical smoke extraction facilities;
(4) the steel frame, steel trusses or steel space frame roof structure should be used in fire prevention spray materials for protection, to improve its fire-resistant performance;
(5) the electrical equipment and electric circuits, frequent repair, competition in the Hall when inactive, to eliminate fire hazards, should cut off the power supply (with the exception of fire power);
(6) to the regular inspection and maintenance of fire and smoke control equipment, fire power, protection devices good sensitivity.