Based On The Simulation Study Of Smoke Spread In Underground Garage Of Pyrosim

With the growth of the national economy,the number of motor vehicles in China is increasing rapidly.At present,the above-ground parking Spaces have been unable to meet the needs of urban residents,so the development and construction of underground garages have come into being.The underground garage not only solves the parking problem for the residents,but also brings the risk of fire.Underground garage contains a large number of cars,adjacent vehicles clearance is also small,and each car oil tank contains considerable fuel or gas,once a fire will quickly ignite nearby vehicles,expand the fire,to reach the third stage of the fire development stage(comprehensive development stage).In addition,there is a lack of doors and Windows in the underground garage,and it is difficult to interact with the outside environment.The heat and toxic gas cannot be discharged in time,which poses a great threat to the safety of the trapped people.Therefore,it is of great significance to study the law of smoke spreading in the underground garage.In this paper,through field investigation of maternal and child health care hospital in hefei high-tech zone and combined with the collected CAD drawings,Pyrosim software was used to build a 1:1 three-dimensional underground garage model.By analyzing the visibility,temperature and CO concentration distribution of the underground garage in different scenarios,the influence of different exhaust outlet layout,exhaust equipment power,air supply system and spray system on the smoke spread is obtained.The main conclusions are as follows:(1)Compared with the natural exhaust,mechanical exhaust significantly improves its ability to restrain the spread of smoke.The side exhaust arrangement of the exhaust outlet contacts the smoke earlier than the top exhaust arrangement,and the smoke exhaust effect is better.The side exhaust arrangement can form the scale exhaust at the early stage of the fire,while the top exhaust arrangement can form the scale exhaust at the later stage of the fire.(2)When the size of the building space is certain,there is a dividing value for the power of the smoke exhauster.The greater the power of the smoke exhauster before the dividing value,the smaller the temperature and CO concentration will be.After the dividing value is exceeded,it is no longer proportional.(3)Under the premise of mechanical exhaust,only adding air supplement system can greatly improve the visibility of fire partition and reduce the CO concentration,but theindoor temperature will increase;Only adding spray system can greatly reduce the temperature of fire partition,but the spray system will increase the concentration of indoor CO and reduce visibility while inhibiting combustion.The coupling of exhaust system,air supplement system and spray system can improve the disadvantages of the coupling of two separate systems,which can not only greatly reduce the temperature of the fire partition,but also control the CO concentration and visibility.Finally,according to the research results of this paper,and combined with the previous study on the spread of underground garage smoke,the underground garage in the design of ventilation and smoke,put forward reasonable Suggestions.Figure[55]table[4]reference[52]...