Research On The Reliability Of Fire Water Supply In Ancient Cities And Towns Based On Fire Risk

Municipal fire water supply is the main source of fire fighting on-site,and adequate fire water supply is the prerequisite to ensure the successful extinguishing of fire.At present,the design of municipal fire water supply in china is usually based on the number of urban population to determine the lower limit of firefighting flow Such methods in urban areas used for fire safety design is better,not easy to spread inter-building fire can basically meet the fire extinguishing requirements,but for some small population,fire danger of ancient towns,may lead to the problem of inadequate fire water supply.China’s ancient towns are composed of low-fire-resistant wood structures such as,civil,brick and wood structures,and which lead to the following problems small building spacing,large fire load,many fire hazards and inadequate fire-fighting facilities.In the event of a fire,if there is not enough fire water supply,the fire will spread rapidly,resulting in the phenomenon of fire camp.In view of the above problems,this article comprehensively uses fire dynamics,municipal pipe network hydraulic model analysis and reliability theory to study the reliability of firefighting water supply in ancient cities and towns based on fire risk.The main research contents are as follows:1.the study combines fire spread simulation technology to analyze the fire spread of ancient town buildings,use regional simulation technology to study the fire characteristics of individual buildings,and network simulation technology to study the fire spread characteristics of building groups,as well as obtain buildings under different fire scenarios and at different times.The heat release rate of group fires further gives the fire water demand at different times.According to the statistical data of the fire brigade’s arrival time during the fire in the ancient town over the years,the fire water demand during the fire intervention time is determined.2.select the Water GEMS software to construct the hydraulic model of the water supply network in the ancient town,and use the iterative assignment of water demand and the calculation of the system pressure to simulate and calculate the municipal fire water supply flow in different areas,and calculate the fire water supply capacity of the water supply pipe network in different areas of the ancient town.3.according to the fire-fighting water demand under the spread of fire and the fire-fighting water supply provided by the water supply pipe network.In line with the basic theory of structural reliability,study the reliability of water supply in ancient towns based on fire spread,and verifies whether the water supply flow of water supply network in ancient towns meets the requirements of fire fighting water flow.4.combined with the analysis of the reliability of firefighting water supply in an ancient town in Yunnan Province,the results show that the ancient town is located in Area C with dense building layout,and its firefighting water supply capacity is the lowest,and its failure probability is 0.488,far away from the commercial center.The fire water supply capacity of Area A in the area is better,and its failure probability is0.211.From the reliability of the fire water supply capacity of the four typical areas,it can be known that the ancient town has a large area with the risk of fire spread risk.In case of a fire,if the fire intervention time is not timely,the water supply pipe network of this ancient town may have the problem of insufficient fire water supply.