【 Weak current College 】 large space building fire design discussion on three major facilities

Introduction
In recent years, with economic development and building technology continues to progress, a number of large space buildings throughout the country have been invested, and further growth trends for these large buildings such as town hall, gymnasium, exhibition hall, Terminal, etc., single-storey building area is very large, floor space of ultra high, cannot be separated internally, their special use request to architectural design and contradict current fire codes, use the existing fire design specification cannot explain and identify the perfect fire protection design program, and such big space construction and there is a dangerous level higher, fire spread speed level, must be based on the existing norms, and drawing on the domestic and foreign advanced technology and new products, identify a set of reliable fire-fighting facilities and design ensure the safety of their use.
In accordance with the automatic sprinkler system design specifications "section closed shower 6.1.1 system setting places restrictions on the height of 8 metres, it is clear that such large space buildings cannot adopt closed sprinkler system.
In accordance with the automatic sprinkler system design specifications "section 4.2.5, has one of the following conditions, should be set in the shower system:
1. the level of the fire spread rapidly, the closed-head open can not be timely to fire sprinkler effective coverage.
2. Interior headroom than 6.1.1 this specification, and must be promptly at the beginning of fire fighting. Deluge system is an open-type automatic fire extinguishing system, in the event of a fire, after the deluge valve opening, all within the protected area with water spray nozzles. Using deluge system to efficiently fight fiercely, spread rapidly burning fire. However, for such a large space of the building, water consumption and water losses are large, in system design and construction, there are certain difficulties and deluge system affectedby fire detection system shall confirm that the fire control, and specific regional fire before starting the sprinkler, resulting in fire and sprinkler fire between added a confirmation link; if using infrared correlation detector, affect the flexibility of using functional construction, for example, in the exhibition building using infrared correlation detector, hanging over the years, mark, advertising and decorating, for their shelter and false alarms, and its price compared with the General probe and more expensive.
With the rapid development of China's national economy, as the building technology and the continuous development of the architectural art, large-scale construction and special building more and more, the requirements in the building structure, modeling, and so on traditional programming breakthroughs and innovations, new and large buildings for fire danger and fire hazards are increased, the traditional design method and design specification is more difficult to meet the needs of the building fire safety design, strictly follow the existing norms, the often limited the application of the building, also limits the designers ideas freely.
Fire technical development, to modern architecture and design offers a new means of fire. New fireproof building materials, components and firefighting equipment and systems, for building fire safety design provides new ideas; to increase fire safety design flexibility and diversity of choice.
In recent years some very large building, fire protection design by provincial public security organization experts to address the fire problem. From the authority of the experts on fire safety design portion of the Super specification technical chats and demonstration, in the fire safety consensus, determine the project's specific fire design.
This way, the international processing of these types of issues more popular design method of performance-based design. As early as 1985, the United States held the first international fire safety science Colloquium, formally proposed a fire science (FireSafetyScience) and fire safety engineering (FireSafetyEngineering) concept.
Fire safety engineering is fire, fire protection engineering and system security works closely with formed on the basis of the application of a highly interdisciplinary, application engineering principle methods, process and its impact on fire for scientific decision-making analysis, it stressed the high degree of system security, considered a variety of factors, of how to implement construction (construction) construction of overall security.
Fire safety engineering development for the improvement of buildings against fire. Performance-based design is to fire safety engineering for the guidance, establishing fire performance-based fire protection facilities (PerformancebasedFireProtectionDesign), usually referred to as the "performance" fire safety design.
Performance-based requirements depending on the particularities of fire development of buildings to determine its fire prevention needs, specifically to make fire safety goals, fire loss goals and objectives to achieve good design.
From the 1980s onwards, Australia, New Zealand, Canada, Japan, the United Kingdom, United States, Sweden, Finland and other developed countries have conducted a performance-based fire protection design aspects of the research work at the national level, and achieved varying degrees of progress and results.
Performance-based design in China is still in preparation for exploration stage, yet it has begun to apply in some extra space, regulating the construction of the fire protection design.
According to the performance of guiding ideology, summing up in recent years some oversized building fire safety design and foreign design information, we believe that for large space building fire design, in addition to using the traditional norms of fire hydrant system, closed sprinkler system (local small space), in the large space should be used (a) the application of rapid response early suppression nozzle closed sprinkler system. (Ii) setting up automatic fire-fighting water gun system. (Iii) automatic water gun.
Early rapid response inhibition nozzle closed spray system
Fast response to early suppression nozzles ESFR (earlysuppressionfastresponsesprinkler) is a United States development production in the late 1970s. It's response time index of RTI < 28 + 8 (ms) 05 (RTI to reflect the nozzle up blasting parameters temperature time), The characteristics of the nozzle as responsive, water drops, the flow is large, high pressure, fast suppression fire, domestic and foreign practice and research has proven that the nozzle can be used to 13 meters of height, which is initially used to protect a high stacking warehouses large flow dedicated sprinkler, exhibition halls, museums etc. larger space building and warehouse in fire characteristics have certain similarities with fire spread speed levels, therefore we believe from 9 to 13 meters large spaces with applications quickly respond early suppression nozzle closed sprinkler system is more feasible fire safety design. References to the sprinkler system design code 5.0.5, 5.0.6, the role of area effect by 300m2 calculation, area open nozzle is 12, the minimum working pressure nozzle, spray intensity 0.5Mpa 16L/min.m2, this system design flow 1.3 × 16/60 x 300 = 104L/s, fire water tank and a storage capacity of 104L/sx3.6 = 375T.
Automatic fire-fighting water gun system
For height greater than 13 meters of space, especially with high aesthetic requirements grid structure and architectural glass-roof, although closed sprinkler systems can play a role in the protection of the steel roof truss, but in the actual design and construction, especially for irregular roof, there is considerable difficulty.
Currently, Japan, Europe and the United States and other countries in the airport, the stadium and other large space building, the widespread use of fire-fighting water gun system, the system of early commonly used in the Terminal and the large open-air Depot, in recent years been increasingly applied to indoor space places such as Japan Kansai Airport, indoor stadium, Dongguan International Conference Center, Shenzhen, Tianjin Binhai international automobile city, etc. Automatic fire monitor system, remote sensing, automatic control, automatic alignment of self-locking, automatic sprinkler fire points, and can be combined with the fire detection system, with dual-band image automatic fire detection and remediation technologies space positioning and optical section image smoke detection technology to solve large space fire alarm, control distance, protected area, reaction speed, high reliability, remote fixed fight early fire.
Overseas development of fire-fighting water cannon and application technology is more mature, such as Japan hochi machine gun, advanced design, preparing fine, superior performance, but its expensive, each about 100 million RMB. Domestic in recent years started to fire water cannon, fire, Shanghai Research Institute of development, China Hefei University of technology company Lian security have been successfully applied to the fire-fighting water cannon fire indoors.
Automatic fire-fighting water cannon linkage system with fire detectors and alarm display of the image, through the linkage controller linkage, scan to determine the ignition point coordinates, driven fire-fighting water cannon alignment, and started the fire pump, pressure relay set pressure value is automatically opened fire sprinkler electromagnetic valve. When the fire detector end alert or within a set time, linkage controller turns off the pump and close fire solenoid valve.
At present, the common fire-fighting water cannon, such as a water cannon, EL570 maximum current capacity of 1200 l/min (20L/s, water cannon population pressure 8-10bar, maximum range up to 50 m) EL367 fire monitor, maximum flow-2400 l/min (40L/S), water gun inlet pressure 8-10bar, maximum range up to 80 meters.
Above water cannon horizontal rotation position can range from zero to 90 degrees to the right of the left, vertical rotation range from + 60 ° c ~ 85 ° c up to-
Under the fixed fire-extinguishing system design specifications "(national standards for approval of the draft), water cannon system from start to muzzle blast water time should not be greater than 5min. Fighting compartment fire-fighting water continuously supply should not be less than 1hr. Indoor fire monitor layout should guarantee that any of the protected area of a site at the same time in at least two water cannons of within the scope of protection.
Case study: using EL367 water monitor, the system design flow: Q = 1.2 × 2 × 40L/S = 96L/s fire water tank storage capacity 40L/S× 2 × 3.6 = 288T. Fire-fighting water cannon system in indoor applications, although the one-time investment is large, but it solves the traditional fire-fighting facilities could not solve the problem of large space fire prevention and fire suppression fast, reliable, simple, and can be combined with the pipeline interior decoration reasonable layout, does not affect its appearance and functionality, is the most ideal indoor fire fighting facilities for large space.
Automatic water gun unit
In addition, relevant information from some to a superficial understanding of such as are currently in Japan Chiba City sports complex automatic water gun used by the device. Chiba City Gymnasium of the racetrack is one of about about 18m 90m×56m, big space. It's fire detection fire extinguishing system selected was scanning fire detection fire extinguishing system selected was scanning fire detector and automatic water gun.
The stadium of fire detector and past use of fire detectors, fire occurs, even if not yet a hot gas or smoke, the detector can be perceived. In other words, by scanning incoming fire of radioactivity, to perceive a fire, measured position, very close to the people of Visual effects. Scan-fire detectors in principle and in recent years, extensive use of the "principle of radiation thermometer".
The stadium of automatic water gun device into remote air pressure type vents and to prevent direct injection of short-range spray nozzle, and you can select, toggle, so as to achieve effective protection of the purpose of the competition venues. The effective range of spraying water, since the maximum level of the spray distance 80m, approved its effective spray rate 4.82L/min.m, especially remote use pneumatic nozzle and the nozzle in General, you can achieve with low water pressure to achieve large sprinkling even remote water effect. In addition, spray out of the water in fire over the formation water curtain type object falls, therefore, should not be formed on the spray obstacles, and has a higher security.
In the competition venue set two scan fire detector and a spray gun. In the spray gun unit including pump room pressureSupply unit (pump) and air compression device (compressor), ensure that enough water and air pressure.
In addition, fire control, set the system monitor control plate and spray the central console. Design competition will scan fire detector, through two conventional monitor, in the event of fire, the fire location immediately signal sent to the system monitor tray monitor, the monitor is determined by the calculation are the coordinates where the fire, in the action part determine the power of control of the sprinkler knob to dial to fire location and determine the range of Jet. Next, the operator starts pressurization water and air compression device for sprinkler. In addition, the operator may also, on a case-by-case basis, the fire Chamber spray gun control desk or in the installation manual airbrush onsite operational control.
This sprinkler is another characteristic of handsome in appearance, it can be fixed sprinkler installation can be buried, that is, fully-embedded into the surrounding wall colours and materials of the same tile decoration, interior design and harmonious appearance. But this system is not currently used in the country.
Fire safety design in buildings is a comprehensive scientific, is made up of specialized (buildings, structures, air conditioning, electrical, water supply and drainage) common safety measures, and of integrated directly in fighting fires when an automatic fire extinguishing system, in the light of national conditions and the relationship between the economic system, our current large space architecture both in the design, development, fire products there is still a certain gap, this requires that we fire agencies as soon as possible to learn the experience of foreign advanced technology, the development of new products designed, in fire-fighting system designed to give priority to ensure personnel safety in the fire, while at the same time to consider how to reduce the incidence of fire and fire losses, to prevent fire spread over large areas, minimize fire on property and environmental damage, the use of performance-based design ideas to make up for the inadequacies of current fire codes, adapt to the rapid development of the community demand, maximize the protection of people's lives and property.