【 Weak current college 】 building ventilation and smoke---III high-rise fire smoke

This section describes the skyscraper fire and smoke partition concept, aimed at the fires to effectively control and will harm the most timely discharge of flue gas. Here are more detailed descriptions of the flue gas diffusion mechanism, high-rise buildings in the form of fire smoke and commonly used fire protection, smoke control equipment and parts. 　　In the study should find out fire zones and smoke partition concepts and role in understanding the different forms of fire and smoke.　　I. Overview of high-rise building fire smoke 1. fire prevention and fire-proof partitions is to prevent fire spread and fight the fire, the smoke is the smoke from the fire, be excluded, to prevent the spread of smoke out to ensure the smooth Interior staff to evacuate the premises. In high-rise buildings fire smoke, usually in the design of the building is divided into a fire, smoke unit, use the firewall (or smoke wall) and fire doors, fire smoke measures taken, the fire and smoke control within a certain scope, reduce fire hazards.　　These fire protection, smoke unit known as fire and smoke partition.　　2. smoke diffusion mechanism of wind pressure refers to the air flow blockage, slower, kinetic energy into pressure energy resulting in pressure. Flue gas refers to substances in the incomplete combustion of solid and liquid particles suspended in the air.　　Flue gas flow diffusion, mainly affected by wind pressure and heat.　　Hot pressing or chimney effect refers to when a building's internal temperature is higher than the outside air temperature, in buildings of shaft (such as stairs and elevator shaft, equipment pipes wells, vertical channel) produces a rise in the phenomenon of hot air.　　When the lower portion of a building or room with a fire in the wind surface, because of the wind pressure and heat, fire caused damage to the top of the building or the Lee side room fire caused much harm.　　Smoke control of high-rise buildings, often using natural gas, mechanical smoke and smoke and other forms.　　Second, the skyscraper fire smoke form 1. natural gas Natural smoke is the use of pressure and heat for power of smoke.　　2. mechanical smoke mechanical smoke is take mechanical pressurization mode to fans of gas flow and pressure control for flue gas flow direction of the smoke. Smoke in front of the stairs and elevator room, fire and both combined with front room, mechanical smoke facilities should be set. If smoke stairs staircase or combined with former room have spread of balcony, porch or former indoor alcove has different opening towards the outside Windows, natural gas, the stairway can open flue facilities.　　Refuge layer for all closed asylum layer, should be set pressurization facilities. Staircase every 2 ~ 3 layer sets a diffuser; each layer in front of the room should be located a diffuser. Pressurized air should be used since the vertical type louver or normally open louver; when used normally open louver, should pressure blower pressure out of the tube on the check. When the design is normally closed, open burning fire only layers of air.　　Diffusers should be manual and automatic opening device and start with pressurized air feeder device chain.　　3. smoke take mechanical ventilation to fans of gas flow and pressure difference, the use of exhaust gas piping fume emission or concentration of the diluted gas. How to smoke does not have natural smoke conditions or difficult for natural smoke in the aisle, room, atrium and basement. The requirements for mechanical smoke extraction as described below. ① 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 1m. ② exhaust vents should be equipped with manual and automatic opening device, normally closed, when the fire is only opened fire floor of the exhaust port. ③ smoke partitions from the exhaust port within the furthest point of the horizontal distance shall not exceed 30m. Aisle of exhaust vents should be arranged in the opposite direction with the passenger evacuation. ④ in exhaust pipes and exhaust blower entrance should have a temperature of more than 280 ° c can themselves off smoke fire dampers. ⑤ exhaust fan should guarantee in 280 ° c can continue working 30min. When any of the exhaust vents or exhaust valve is opened, the exhaust fan should be able to start. ⑥ exhaust duct must be non-combustible material. Installed in the exhaust pipe in the ceiling, the insulation should be non-combustible material, and should remain with the fuel is less than the distance 150mm. ⑦ mechanical smoke extraction system and ventilation, air conditioning system should be set separately. If the combination, must take the reliable fire safety measures and should comply with the smoke exhaust system requirements. 　　⑧ sets the smoke of the basement, you should also set the air distribution system.　　Mechanical smoke extraction system control procedure, can be divided into no fire control room and fire control rooms of two kinds. 4. ventilation and air-conditioning system of the fire prevention the fire, you should try to control the fire spread to other fire prevention Division, in ventilation and air conditioning system, ventilation pipe needs to set the fire damper. Fire damper shall be set at: cross fire partitions partition; cross the room and the room or a room with the fire risk of partition wall and floor; and vertical duct connected horizontal wind road junction; through the sides of the expansion joint.　　Fire damper action temperature is 70 degrees centigrade. Ventilation and air-conditioning piping project in the pipeline, insulation, noise control materials and adhesive noncombustible materials should be used, or hard combustible material.　　Air contains flammable, explosive substances, the ventilation equipment should be used in explosion-proof equipment.　　Third, fire protection, smoke control equipment and parts for fire protection, smoke control equipment and parts mainly fire damper, exhaust valve and exhaust blower etc. 1. fire damper fire damper is fire damper, fire protection control valves, fire dampers and smoke and fire air outlet.　　Fire dampers and fire control valve difference is blade aperture can be adjusted. (1) fire damper control fire damper control mode has a sense of control, Thermistors and temperature control and smoke control, etc.　　Composite control as both control combinations, both in the device, with the thermal element also contains a sense of smoke temperature regulator.　　(2) fire safety valve valve closes drive mode the valve closing fire damper drive modes have gravity, spring force-driven, the motor-driven and pneumatic driven by four. (3) common fire damper ① gravity fire damper. Divided into two kinds of rectangular and circular. Fire damper normally is normally open state.
　　When you need to open the valve, unscrew the bolts before locking the Reed, handheld operating lever, shaking up the valve plate or leaves, connected yirongpian, straighten, tighten the bolt locking Springs after the fire damper to resume normal operation. ② Spring fire damper. Spring fire dampers with two rectangular and circular.
When you need to reopen the valve, installed yirongpian and temperature fuse, shaking up the blades or the valve plate and fixed on core temperature fuse, fire damper will return to normal working condition. ③ Spring fire control valve. There are two kinds of rectangular and circular. Usually used as air volume regulation normally open fire control valve, fire and air temperature higher than 70 ° c, yirongpian fuse, which fuses pin clutch plate, clutch lay the disengaged, shaft ends of the torsion spring release, valve leaves off. ④ smoke fire control valve. There are two kinds of rectangular and circular. You can apply to have a smoke fire requirements of air conditioning, ventilation system, its structure and fire control valve, reset and air flow adjustment method is the same as with fire control valve. ⑤ fire air outlet. To have a fire safety requirements of ventilation, air conditioning system with air, back to the air inlet and outlet. ⑥ pneumatic valves for fire protection. For Halon 1211 and 1301 automatic fire extinguishing systems linked by ventilation, air conditioning duct. Air operated fire damper when you must manually reset the system first relief, and then reset, open. ⑦ electric fire damper. Installation in fire protection requirements for ventilation and air conditioning duct, fire resistance, power off, reset spring immediately close the valve. You can open the valve after power-on reset. ⑧ electronic automatic smoke fire damper. Use of electronic technology and logic circuit technology. Fire automatically turn on or off, and automatic alarm. 　　Use the controller on one or more smoke fire damper control. 2. exhaust valve installed in the exhaust system, usually is off, there is a fire, through control center signal to control the work of the executive bodies, realizing the valve spring force or torque of the motor.　　Equipped with temperature sensors devices for exhaust valve, the valve opening, fire temperature reaches an action when action temperature, the valve in the spring force shut down to prevent fire spread along the exhaust pipe.　　(1) of the exhaust valve and exhaust valve according to the classification of control can be divided into two kinds of electromagnetic and electric; press the structure can be classified as exhaust valve, Deco flap-type exhaust valve and smoke fire dampers; press appearance can be divided into two kinds of rectangular and circular. (2) common exhaust valve and exhaust valve ①. It is installed in the exhaust system of air pipe, usually leaves off, of fire smoke detectors, fire alarm signal issued so that the control centre will exhaust valve electromagnet power is switched on, the blade quickly open, or artificial manual quickly leaves open to smoke. Exhaust valve has two circular and rectangular, and the same exhaust fire damper, exhaust valve, the difference is that without temperature sensor. ② smoke fire dampers. It installed parts and leaves off and exhaust valves are the same, the difference is that it is fireproof, flue gas temperature reached 280 ° c, the temperature sensor or manual leaves off, cut off the gas. ③ remote control exhaust valve. It is installed in the exhaust system of the duct or exhaust outlet, closed. Fire smoke for issuing fire signal, control centres to remote controller of the electromagnet power so that the exhaust valve opening, or manually set the valve to open and reset. ④ remote control smoke fire dampers. Its action principle and the same exhaust valve remote control, except that it with temperature sensors, fire-capability, you can manually set the valve to open or reset. ⑤ plate heat exhaust port. It is installed in the aisle of the roof or wall and smoke Chamber before, can also be directly installed in the exhaust duct of the Terminal, its action and the same exhaust valves in General. ⑥ leafy exhaust port. It is the exhaust valve and the outlet of the General installation in the aisle or the smoke Chamber, windowless room exhaust systems, smoke vents installed in the side wall of the former Interior, its action and the same exhaust valves in General. ⑦ remote control leafy exhaust ports and remote control leafy fire smoke exhaust port. Remote control leafy exhaust ports and remote control leafy fire smoke exhaust mouth look identical difference to remote control leafy exhaust mouth no 280 degrees centigrade temperature sensor, its action mode and remote control exhaust valve and remote control smoke fire dampers are the same, the installation location and the same exhaust mouth more leaves. ⑧ Electric smoke fire dampers. It can output after the valve opening, when the exhaust pipe signal air temperature reached 280 ° c, the valve is closed automatically, at the made off signal. 　　The valve can be manually reset or power-on reset. 3. smoke smoke ventilation fans can follow the universal fan, or a dedicated fan of fire smoke. Commonly used fire smoke dedicated fans have HTF series, ZWF series, type type. W-X Flue gas temperature at low to long running, flue gas temperature is high and it may contiguously work a certain length of time, usually two retaining more speed.