【 Weak current College 】 on smoke control in underground entertainment technology---Power By 【 China power house network 】

With the continuous development of the economy, the space of human existence, many high-rise buildings and underground civil architecture. Because of the particularity of the two types of building, once a fire will bring great losses, in particular, because of its underground buildings and the land the building is very different, so the relative ratio above the number of fires, deaths, particularly in large fire, underground construction deaths more than above. Therefore the underground building fire requirements should be more rigorous.
Underground public entertainment's notable features is the personnel-intensive, fire prone to congestion; electrical load, combustible materials use, easier to fire; also because of the underground building sealing, natural ventilation and natural lighting conditions worse than those above, fire burns a lot of smoke, smoke makes people-of-sight, visibility greatly reduce and even identify ambiguous evacuation direction, causing serious damage. So underground building ventilation problems should be more concern.
This article is based on the underground public entertainment features and characteristics of fire, to explore the underground public entertainment for smoke control design.
Above the fire smoke rising personnel to Downlevel fled, smoke in the vertical direction of diffusion flow routes and the route of the evacuation activities, on the contrary, when people fled to the burning layer the following place is more secure, underground construction is not. Smoke rise to top flight personnel, personnel in the vertical direction of evacuation speed well below the smoke rose faster. If personnel at the level of evacuation in the response of the fire, or anxiety, or can't clear direction and delayed the evacuation, is very dangerous. Smoke control design is very important.

A division of, smoke partition
Underground public entertainment floor down the pipeline, consider decorative appearance, generally adopted the suspended ceiling, ceiling still required smoke hanging wall dividing smoke partition, smoke vertical walls and occupies the room height to 0.5m Gu to spatial effects, you can choose the usual away combined hanging fire activities for vertical wall of smoke. Smoke partition area should not be greater than 500 square meters, but when the roof from indoor floor-or roof height of 6 meters above the sea level, is not affected by this limitation; smoke partition must not cross fire partitions.

Second, the choice of smoke
Underground public entertainment must adopt smoke, this is also characteristic of the underground building. In order for the underground public entertainment better smoke effects, underground public entertainment smoke use comprehensive air exhaust and smoke exhaust and intake forms a good convection circulation system.

3. air supply and exhaust of
Mechanical smoke extraction system with one or two smoke partition volume smoke, smoke less 60m3/© o, h-exhaust fan of minimum exhaust volume should not be less than 7200m3/h; in order to save investment, often using a blower with three or more smoke partition exhaust tasks, you should press the largest smoke partition area per square meter than 120m3/h, the air volume of not less than 50% of the exhaust system and must be less than the amount of exhaust smoke, fire room is in the negative pressure, air speed specification requirements to less than 7m/s, wind speed through the General destruction of fire room smoke and air layering, make space at the bottom of the air and flue gas mixture, the threat to the safety of the personnel of detention.

4. send the exhaust port layout
1. the dimensions of the exhaust vents and layout
Exhaust outlet size and layout to a large extent the impact of smoke effect. Because of the smoke layer floating in the upper room, smoke exhaust outlet should be located in the ceiling plane or from closer to the height of the ceiling. Too low will breathe in the air, the lower Chamber so that the exhaust volume reduction. Exhaust outlet flow should not be too large, otherwise they will be a large number of air entrainment, reduce the smoke, fume outlet velocity is not greater than 10m/s, for a large room, can be dispersed more exhaust port. Exhaust outlet from the farthest point of the room level distance not greater than 30m, too much distance of exhaust smoke, smoke less distant smoke, fume outlet location should not be too close to the exit. In exhaust pathway, slit-exhaust ports on throughout the exhaust vents are valid, and the rectangle is not easy to smoke outlet drain channel two smoke, as in Figure 1 and 2. Usually the minimum exhaust port area is generally not less than 0.04 m2. When setting the exhaust vents, attention should make evacuation exhaust direction and in the opposite direction.
2, mechanical ventilation and smoke mix
Many public entertainment venues are the exhaust port ATD in ceiling, air supply and exhaust use linkage control, as in Figure 3, an underground public entertainment of smoke control system design. Its supply outlet located at the top center, the top of the exhaust port is set in the wall.
Smoke ventilation system startup, the fresh air from the air to flow down the Middle, the air exhaust port around the mouth to the exhaust gas flow, as in Figure 4. This design method there is a big defect that prevents effective removal of smoke. If you do not exhaust ventilation system, fire smoke in buoyancy effect rising up to the floor, horizontal diffusion. When gas is cooled to a certain temperature, flow. comparative figures 3 and 4, the flue gas flow path and air supply system produced by air routes to the contrary, fire smoke will spread throughout the space. Exhaust vents should be arranged in smoke partition centered, left exit two meters above the sea level. To have more than one smoke partitions how organizations of smoke flow control can be taken through the? air branch pipe on valve only to the same fire partitions does not detect fire and smoke partition air, exhaust port is still smoke fire valve control the action, as in Figure 5.
From b, and C D entered the area of wind speed ratio at low diffuser. Air flow path and fire smoke flow line of the conflict, when the fire spreading to the B, D, as in Figure 6. B, D district of air, exhaust vents to start off, the smoke exhaust port area c, A, E closed area into the wind from opening A, B E entered into, C, D, B, D district of flue gas exhaust discharge for control selects the flue gas, air in the form of more conducive to smoke.

5. machineArmed exhaust system combined with ventilation and air conditioning
Underground public entertainment in sometimes in order to give full play to the investment performance, mechanical smoke extraction system combined with the air conditioning system, and designed ventilation and air conditioning systems should be according to the requirement to exhaust system design. Note the smoke could not adopt the air conditioner, filters, exhaust vents should be equipped with fire damper (effect of temperature equal to or less than 280 degrees) and remote control of the exhaust valve automatically switch. Steel tube wall thickness to the exhaust pipe and generally not less than 1.5mm. And duct insulation including adhesive must be nonflammable materials.

VI. conclusions
Underground public entertainment fire safety design in the most important design issues that smoke control in underground public entertainment smoke control system design, you should first consider is the determination of system design and development process of fire, these issues directly affecting fire safety, smoke district, smoke hanging wall settings, piping layout and other important issues that need to be combined with the specific situation of the building.