Research On Fire Control Technology Of Wooden Structure Ancient Building Based On High Pressure Fine Water Mist

Wooden structure of ancient buildings have a large fire load,low fire resistance level,fire spacing and other problems,once the fire is easy to cause the spread of fire between buildings,and ancient buildings are not renewable,the fire will cause irreparable economic losses,historical and cultural losses and social impact.Therefore,in the early development of fire in the wooden structure of ancient buildings to extinguish the fire or fire control in a single building to cut off the spread of fire between buildings,can effectively control the spread of fire.Among them,high pressure fine water mist system is a new fire extinguishing and fire control technology began to be used in ancient buildings,when the fire occurs not only to quickly extinguish the fire can also produce an effective fire separation.Considering the high-pressure fine water mist system of fire extinguishing and thermal insulation and cooling effect with the water mist nozzle parameters,water curtain arrangement position and other factors,for the above-mentioned issues,this paper mainly carries out the following research:(1)Combined with the fire experiments that have been carried out in wooden buildings,the FDS model was established to verify the effectiveness of numerical simulation techniques.On the basis of this paper,a wooden structure in Lijiang City,Yunnan Province,as the object of study,respectively,the establishment of the ancient building indoor fine water mist fire extinguishing model and outdoor high-pressure fine water mist curtain fire separation model.(2)The ancient building indoor fine water fog fire extinguishing experiments and numerical simulation studies,taking into account the fine water fog nozzle in the atomization cone angle,spray pressure,spray speed and particle size and other factors when the effect of fire,and according to the fine water fog indoor fire extinguishing time,combustible heat release rate changes,temperature values at different heights,carbon monoxide and oxygen concentration changes in the analysis,comprehensive comparison to determine the fine Water fog nozzle parameters of the best set program.(3)Outdoor high pressure water mist curtain heat insulation and cooling performance of ancient buildings,according to the heat insulation and cooling effect of high-pressure water mist curtain and its location,through numerical simulation to obtain the fire outside the building high pressure water mist curtain in different locations of the thermal radiation value,temperature value and heat insulation and cooling efficiency,so as to determine the best arrangement of the water curtain program.To verify the effectiveness of the water curtain fire separation,a full size high pressure water mist curtain fire experiments,the results show that the water curtain has good thermal insulation performance.(4)Through data fitting to derive the relationship between the value of thermal radiation and fire spread distance under the action of high-pressure fine water mist curtain,the critical thermal radiation flux value of wood as a wooden structure of ancient buildings can be ignited based on the judgment,the calculation of the minimum fire safety distance of the building under the action of high-pressure fine water mist curtain,the findings of the study can provide a reference basis for the protection of wooden structure of ancient buildings fire.