【 Weak current College 】 large room smoke exhaust system of the

Introduction: discusses the design of large room exhaust system for smoke partition in the partition and the basis of the importance of the greater amount of exhaust smoke, the entire fire partition full exhaust point of view, on the exhaust and smoke exhaust system settings and conversion analysis.
Keyword: room exhaust ventilation
With the development of our modern buildings, underground storey high-rise building features more and more complex, many developers in addition to the use of underground floors for equipment room, garage, underground layers for convenience stores, warehouse, etc. Surface with the city wide sound development, large areas of underground Mall people more and more. Under the high civil building design fire protection standard (hereinafter referred to as the "regulations"), the defense works design fire protection standard (hereinafter "the regulation of air defence), the underground part of the building should be a maximum flue gas facilities. The author of several projects designed to summarize, the large room smoke control system design experience and views.
1 smoke partitions of the partition and system determination of smoke
The doctrine of "section 8.4.2 bar gives the amount of exhaust smoke exhaust fan to" take a smoke partition exhaust or clearance height is greater than 6.0 m of designated smoke partition room should be per square meter area of not less than 60m3/h calculation (single Typhoon machine minimum exhaust volume should not be less than 7200m3/h), "take on two or more exhaust smoke partition should be maximum preventing smoke partition area per square meter than 120m3/h calculation". The regulation of air defence in section 6.3.1 gives the amount of exhaust smoke exhaust fan to "take one or two exhaust smoke partition should be the part of the total area of each square is not less than 60m3/h, but the exhaust fan of minimum exhaust volume should not be less than 7200m3/h; take three or more exhaust smoke partition should be one of the biggest smoke partition area per square meter than 120m3/h.
Visible, the amount of exhaust smoke exhaust system and smoke partition area there is a direct relationship. Smoke partition by smoke or vertical walls, partition from ceiling to highlight not less than 500 mm of beams. Large room (such as supermarkets, shopping centers, warehouses, etc.) in many cases the main beam height of about room 700mm no ceiling or grid ceiling, beam naturally add rooms divided into many small smoke partition. Some designers an exploit these natural smoke partition, press one of the biggest smoke partition area is not less per m2 120m3/h to calculate the amount of exhaust smoke, which concluded that the amount of smoke to small, generally not more than 10000m3/h, and the exhaust system-mouth a lot, making the system more complex. And the exhaust system itself is unrealistic, because of the large room fire partitions more separated by fire shutter, face a fire zones fire spread faster, even the initial smoke or fire is very difficult to control pump two smoke zones, thus requiring more smoke exhaust valves at the partition, and the system of smoke exhaust system can only be met two smoke partition at the same time, smoke, it is clear that this practice is not advisable.
Literature [1], on the exhaust port settings and smoke partition Division are as follows: "in principle, each smoke zone should set the exhaust vents, larger room, from the roof down prominent not less than 500 mm of beam will divide the room out of the many small smoke partition, if each smoke partitions are located exhaust vents, ducts and exhaust port number. Can be integrated into account various factors, the room as if the mouth, with each group beams surrounding into a small area only brings together and stay smoke. "This large room exhaust system design time must be in accordance with the" factors "Division of smoke partition, and then determine the amount of exhaust smoke. This approach is consistent with the doctrine of law and the civil defense of the requirements of the regulation, but may save two questions; second, the people designated smoke partition to use some of the highlights from the roof down not less than 500 mm of beam as smoke partition boundaries, but divided out smoke partition has the same beam, the smoke function is the same, but not as smoke partition boundaries, the author believes that this Division of smoke partition slightly ambiguous.
In accordance with the above idea for exhaust system design time, smoke partition of partition is the key, it directly affects the amount of exhaust smoke extraction system, the number of valves and control. However, the designers for large room smoke partition of classification criteria (size, geographical) it is difficult to find a clear basis, can only rely on their own experience. Recommendations for amendments to the large room smoke partition of minimum size limits, given to control large room smoke exhaust system the amount of minimum exhaust. This stage design, partitioning large room smoke partition, the minimum size may not be less than the automatic sprinkler fire system design specifications for malicious code in the area of "function" to value; geographical should reference the corresponding room features to divide, such as warehouses, smoke partition best and architecture Division of heap cargo space. Smoke partition after the partitioning, designers should also be noted that associated smoke partitions around sets clear smoke hanging wall to guarantee no adjacent smoke partition with smoke or less with smoke.
The design concept while in compliance with the regulations of law and the regulation of civil defense, but the actual operation breakdown of features in the rooms are often inconsistent with design, designers painstaking of smoke partition does not necessarily consistent with the actual operating conditions. And the exhaust system, the exhaust gas volume size on the effects of smoke. So, I consider that the use of the increasing amount of exhaust smoke, full of design ideas.
The provisions of the regulations is equipped with automatic fire extinguishing system using a noncombustible or nonflammable materials decoration, underground layer of commercial business Hall, exhibition hall, the largest fire compartment area allows to 2000m2, warehouse not exceeding 600m2. of the newly revised "architectural design fire protection standard, provides the largest underground shop business Hall fire compartment area as the existing design 2000m2., many architects going underground commercial business district area of fire control of 1000m2. Exhaust systems for accident system, there is no need to consider the energy-saving, but rather to security interests. For warehouse, its fuel,The building of the amount of exhaust smoke exhaust system should use a higher value to ensure that a fire evacuation and rescue. According to the civil defense regulation article 6.3.1, each fire partitions as two smoke partition, the volume of the exhaust gas fire partitions is not less per m2 approx. 60m3/h. Or maximum preventing smoke partition size to the amount of its exhaust 500m2, by maximum preventing smoke partition area is not less per m2 120m3/h. This fires the entire fire partitions can be exhausting, or minimum exhaust area 500m2, adapted to the fire spread quickly in large rooms. While this amount of exhaust smoke, many 40000 — 60000m3/h, but by using high pressure head fan, high speed wind pipes system cases, projects or feasible.
2 exhaust system and exhaust system use)
High-rise building, ground floor and basement rooms are difficult to use in large window well natural ventilation, generally equipped with mechanical ventilation system. Fire protection district area of not more than 1000m2, ventilation system the best in fire partition settings so that the exhaust system and exhaust system use. Follow the large amount of exhaust smoke, full of ideas, the exhaust volume and smoke can be a lot worse, then you can use two fans with a duct system, exhaust blower inlet set penumatic 70 ' c closed fire damper linkage with fan; exhaust fan inlet set normally closed, open fire, 280 ' control c to close the valve and exhaust blower linkage. Due to the volume of the entire exhaust system satisfy the fire while exhaust requirements section, so you don't have to fire off vents, just off the exhaust fans, start the exhaust fan that is done the system conversion. If the outlet opening area does not meet the requirements for exhaust gas can be set normally closed exhaust valve, exhaust valve opened fire increased exhaust port area. In this way, the exhaust system switches to the exhaust system, action part at least, the system is simplified, accident when reliability to smoke.
3 large rooms on the ground of smoke control system
Current designers design single-layer construction area growing large shopping malls are usually no mechanical smoke extraction system. Under the doctrine of "8.2 on natural gas, section 8.4 provisions relating to the mechanical smoke extraction, the depth or building Center is equipped with a natural smoke conditions of Atrium, at the same time you can open the window size is smaller than the room area of 2 per cent, this treatment is appropriate. However, in depth, and there is no more than 60m natural smoke exhaust of Atrium, regardless of its size to open the window is not less than the room area of 2% should be considered for mechanical smoke extraction system.
4 on large room exhaust system design considerations
In 1997, October 5, publishing, 1 May 1998, the garage, garage, parking design fire protection standard (hereinafter referred to as the "steam gauge"), section 8.2.2 bar gives "each smoke partitions of the building area is over 2000m2";
Section 8.2.4 shall give the "amount of exhaust smoke exhaust fan should be not less than 6 ACH/h calculation to determine" time.
Currently on the underground garage, smoke control system design had a more mature experience, garage are large rooms, although functional, but with other large room smoke design should have in common. Following on the above requirements making some analysis.
First of all, the steam gauge "will smoke partition area by the doctrine of" no more than 500m2 expanded to not over 2000m2, this should be considered a large Royal room fire spread rapidly, the need for a large area at the same time, the results of the exhaust system features.