Study On Fire Prevention And Control Strategy Of Wood Structure Buildings

There are a large number of historic wood buildings in our country,these buildings have a high cultural and artistic value.However,due to the rapid fire growth rate,the low fire resistant rate,fire fighting equipment disrepair,fire spacing and fire fighting venues serious shortage and other reasons,resulting in wood structure fire have a low success probability of fire extinguishing and easy to spread from building to building.In order to improve the fire safety level of wood structure,and reduce the risk of fire spread,the fire prevention and control strategy of wood structure building was studied in this paper through numerical simulation and theoretical analysis.The main work and achievements are as follows:1.The response time of the detector in the typical wooden structure of Yunnan province was obtained.Using the fire simulation software FDS simulated the response of the detectors in the typical stilt houses and courtyard houses in Yunnan province,and the response process of the detector was plotted in figure.The response time of the smoke detectors and the temperature detectors in the wooden houses was obtained,and the response time distribution that be used as input parameters in the FBIM model was given.2.The effectiveness and timeliness of the method remove roof to extinguish fire was studied.The effectiveness of the method was demonstrated by analyzing the difference of fire heat release rate curves obtained by simulating those fire process at different time remove the roof,the effective time of the method is before the occurrence of the fire flashover was proved,the theoretical calculation formula of the critical time of remove roof was deduced.3.The method of using fireproof cloth to prevent fire spread in wooden structure buildings was studied.The differential method was used to solve the one-dimensional heat conduction process,and the beneficial effects of fireproof cloth and air inter-layer on fire prevention are determined.The calculation formula of wooden facade temperature curve and the calculation formula of critical thickness of fireproof cloth are obtained.Taking lijiang wooden buildings as an example,the critical thickness of the fire cloth was calculated,and the critical time of hang the fire resistant cloth and the temperature curve of the wooden facade were set up.4.Study on the fire brigade rescue model.FBIM model was introduced,combined with the fire development process and the calculation formula of the spreading process,the method of calculating the fire heat release rate of the wood structure building was obtained.The calculation formula of extinguishing water flow and the formula of calculating the success probability of fire extinguishing were introduced.Taking the typical courtyard houses in Kunming as an example,the heat release rate curve,the response time of fire brigades,the intervention time of firefighters,the success rate of fire fighting and the fire extinguishing flow of the courtyard houses was obtained by using the Monte Carlo simulation method.5.Research on fire control strategy.According to the different stages of the fire process,two fire control goals were setup,and four different fire control strategies were put forward.Based on the three different types of buildings:Wending village,Kunming courtyard house and Kunming modern residential,the differences of the three buildings on achieve the goals under different fire fighting strategies was studied,and obtained the following conclusions:Wengding village only rely on the fire brigade for fire fighting will lead to fire spread from building to building,the effective strategy is setting a full-time fire brigade or install automatic sprinkler system,and should also consider the use of removing roof and the hanging fireproof cloth to prevent fire spread method for fire fighting;for Kunming courtyard house,because of the success probability of fire brigade extinguish fire is low,the strategy should consider setting a full-time fire brigade or installing the automatic sprinkler system,only rely on active fire brigade fire,the need for additional fire resistant cloth used to prevent the spread of fire;for Kunming modern residential,relying solely on the passers-by alarm and the fire brigade located in city are still able to control the fire in the initial fire room or fire partition,only to increase the automatic alarm system without the need to set up additional fire fighting measures,it's no need to set up additional extinguishing measures except automatic alarm system.