1. Overview of the new library is located in Maoming brief cultural square, is a city () the public library is the library directory in Maoming, inter-library collaboration and business counselling centre. New library books to scale up to 120 million copies daily reception readers 2000 people, reading seats approximately 1000, Maoming square of important buildings. The new Museum's total area 21781.8m2, ground four-layer, ground floor, with a total construction height 18.40m, central air conditioning. Are taken into account in the library of the underground of diesel generator room, first floor of the fire control centre and computer, four layers of ancient books reading room and reading room for reference information on local documents using gas fire extinguishing system.
2. the choice of gas fire extinguishing system in September 1987, Canada's Montreal world unanimously signed to protect the Earth's ozone layer and the rescue of the entire Earth ecology environment on a global scale comprehensive ban on production and using HCFCs and halons "Montreal Protocol". At this point, as an extremely effective fire suppression system and is widely used by halon 1301 fire fighting system and other similar fire extinguishing system, began to be a ban on the use of the vast majority of countries. At present, replacement of clean gas extinguishant 1301 mainly inergen (IG-541), heptafluoropropane (HFC-227ea), chlorotrifluoromethane (HFC-23) and CO2 are now available on the above four products (see table 1). Name/project IG-541HFC-227eaHFC-23CO2 chemistry 52% N2, Ar 40%, 8% CO2CH3CHFCH3CHF3CO2 design concentration (%) 37.5%-43% 7.5% ~ 10% not less than 40% 15.6% gas release time is not greater than the 60s is not greater than 10s not greater than 10s not greater than the 60s dipping time of not less than 10min is not less than 10min 10min 20min storage pressure not less than 15/20MP2.5MPa15 MPa transmission distance 150m30m60m80mNOAEL concentration 43% 9.0% 50% 20% deaths LOAEL concentration > > 10.5% 52% > 50% LC50 concentration > > 80%-65% of the greenhouse effect has no impact on the equipment without producing HF Acid corrosion to equipment, produce HF Acid corrosion to equipment there is fog phenomenon pharmacy prices higher high and low notes: NOAEL concentration: not observed in physiological or adverse effect of the concentration. LOAEL concentration: observed in physiological or adverse effect of the minimum concentration. Concentration LC50: 50% of deaths in exposed mice test 4h concentration of extinguishing agent. Above all the pros and cons of gas fire extinguishing system, combine the protection area features (such as small, decentralized, transmission distance and often people work, etc.), suitable for the design of gas fire extinguishing system only inergen (IG-541) gas fire extinguishing system.
3, cauterization do gas extinguishing system design 3.1 design principle by spraying, placed an inert gas, reduce the percentage of oxygen in the air (oxygen concentration within 1min down to 12.5 per cent), to prevent combustion; at the same time CO2 concentration increases to 4 percent, to stimulate the lungs breathing. 3.2, system storage devices (storage containers, container valve, hose, one-way valve, safety relief valves, rainwater pipes and pressure indicator), vacuum valves, orifice, selection pressure switches, plumbing, sprinkler and smoke temperature sensor detection system, alarm system and Control Panel. 3.3, counts the parameter minimum design fire extinguishing concentration 37.5% (16 ° c), the largest design fire extinguishing concentration 42.8% (32 ° c). 3.4,
a. agent design usage inergen gas fire extinguishing agent design usage anxiashijisuan, M = XV-M-extinguishing agent design amount (m3) V-protection area net volume (m3) X-submerged coefficient, X = 2.303x (VS/S) xLog [100/(100-C)], S-inergen superheated steam specific volume (m3/kg), can be obtained from the following approximate-: S = 0.65799 + 0.00239T-T-Shield region expected minimum ambient temperature (℃) C-extinguishing agent design concentration Vs-20 ℃ extinguishing agent specific volume, take 0.707m3/kgb. pipeline and container bottle design for the remainder of the amount by 1 per cent of the amount of 2 per cent considered.» C. extinguishant systems, you should design for protection zone extinguishing agent and the system in use on non-net amount of surplus. D. fight combustible liquid fire, electrical fire of minimal design concentration should be 40%, the fight to melting solid fire, combustible solid surface fire, electrical fire of minimal design concentration should 37.5%.3.5
, overall network design a. extinguishing agent injection time, should be guaranteed within the 1min minimal design concentration of 95%. B. General pre-export pressure nozzle should be not less than 2.2Mpa. C. nozzles maximum installation height is over when 6.0m 6.0m should add in the height direction is also used. D. pipeline volume and storage container volume ratio should not exceed 66 per cent. E. collecting pipe orifice diameter in decompression connected to pipe diameter ratio should be at 13 per cent to 55 per cent range.3.6
, protective zone design a. when using pipe network system, a protection zone of the area should not be greater than the volume not greater than 500m2 2000m3. B. protection area of the fire resistance rating envelope should not be lower than the fire rating 0.5h; ceiling should not be lower than 0.25h; envelope can withstand an internal pressure of not less than 1.2Kpa allowed pressure. C. protection area fire keep closed conditions, in addition to other relief estuary mouth, should be able to automatically close before the clean gas. D. protection arearelief port settingsOCKQUOTE > in General, if the reserve is equipped with the outer door, flexible door closer or spring door, if its open area is not less than the pressure of the calculation of the area, the reserve may be no relief. Calculation formula for the pressure outlet as follows:
area Af = Kq/Pf0.5 Type Af-pressure in the area (m2) K-pressure relief area coefficient K = 0.0135 Q-extinguishing spray drop rate, Q = 2.7M/t, where m is the extinguishing agent design usage, t (min) for injection on time. Pf-envelope withstanding intrinsic pressure allows pressure.
4. the system of automatic control, automatic control, automatic 4.1 control should have the auto-detect fires and automatically start the system functionality. Fire extinguishing system for automatic control should receive protection in two independent fire alarm signal to start. Automatic control startup you can set a maximum of 30 seconds of delay, so that the protective area evacuated and off ventilation pipe fire damper. 4.2, manual control every protection zones should be set to a manual/automatic selection switch selection switch for manual and automatic location should be clearly identified. Protection area entrance should set the emergency stop device spews. In all cases, manually start the control should give priority to emergency stop function. Manual start may not start after a time delay and direct. 4.3, mechanical emergency operation when the automatic control and manual control are malfunctioning, the need for a mechanical emergency operations to start, staff are available through the cylinder on the release valve or select valve manual Launcher to start the entire gas fire extinguishing system.
5. closing inergen gas fire extinguishing system, its components are inert gases, gas taken from nature. Its advantages are fire and gas does not have the injury to the person, has no impact on the environment, gas prices are cheap. But the drawback is that the number of cylinders, and storage and work pressure, fire extinguishing concentration demands high, these use to further promote and inergen gas extinguishing system poses some problems. However, relative to other gas fire extinguishing system, Maoming library selection inergen as gas fire extinguishing agent, could be an ideal halon substitutes. (Author: Research Institute of Guangdong Province)
References 1, Shanghai construction for the inert gas IG-541 extinguishing system technical specification for "DG/TJ08-306-2001, 2001 J10112-2, Guangdong standard" heptafluoropropane (HFC-227ea) clean gas fire-extinguishing system design standard》dbj15-23-1999 national standard 3, People's Republic of China to the carbon dioxide fire extinguishing system design code GB50193-93 4, nationwide civil construction design techniques-water supply and drainage
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