Study On The Influence Of Engine Room Ventilation On Smoke Characteristics Of Adjacent Cabin Fire

Marine platform environment is harsh,complex design,expensive,highly concentrated machinery and equipment,there are a large number of flammable and explosive substances and oil and gas storage equipment,once a fire will lead to very serious consequences.The engine room is the key protected area on the marine platform.The cabin is large in volume,with a lot of internal heating equipment and uneven distribution.Therefore,the ventilation system design in the engine room is quite complicated.In order to ensure the uniform air distribution in the engine room,a large amount of ventilation is needed to maintain the normal operation of the machine,and the appropriate air distribution is needed to maintain the appropriate environmental conditions.When a fire occurs in an adjacent cabin,each door of the engine room may be closed separately or simultaneously due to personnel escape,personnel fire detection,operational errors and other circumstances.Therefore,it is necessary to understand the influence of cabin ventilation on the fire smoke characteristics of adj acent cabins.This paper firstly establish the geometric model and determine the fuel parameters,then takes the cabin of the offshore platform,designs a ventilation system based on CCS specification and IMO MSC(Maritime Safety Council)circular No.601,FDS software was used to supplement the cabin ventilation system in the established model,and numerical simulation of the air distribution in the engine room,and a numerical simulation of the air distribution in the engine room of the cabin velocity field and temperature field were analyzed,It is found that 300s is the stable time of air distribution.Then the numerical simulation of the influence of different ventilation on fire smoke characteristics of adjacent cabins was carried out.Under the single engine room condition,by comparing the different source of power,fire source location,cabin opening case engine room ventilation influence on adjacent cabin fire smoke characteristics,the changes of temperature,smoke layer height,visibility,CO concentration and other parameters in the main switchboard room,engine room and corridor are discussed.By comparing the influence of different fire power sources,the change rule of critical time at each position is obtained with the change of fire power in the case of the same engine room ventilation.In the case of the same fire source power,with the change of ventilation in the engine room,the change law of critical time of danger at each position and the change law of spread distance in the corridor is obtained;By comparing the influence of different fire source locations,it is concluded that the fire source location off-center is the most dangerous for the environmental parameters of the main switchboard room,and the fire source location closer to the engine room is the most dangerous for the environmental parameters of the corridor.At the same location of fire source,the critical time of danger in the corridor decreases gradually with the increase of the ventilation volume in the engine room.Finally,by comparing the influence of different openings in the engine room,in the case of the same ventilation in the engine room,the changing rules of each parameter in the case of two kinds of fire source power and different opening ways are obtained,and the changing rules of critical time at each position with the change of ventilation in the engine room are obtained.Under the double engine room condition,by comparing the two fire power,double cabin under three kinds of different working conditions,engine room ventilation influence on adjacent cabin fire smoke characteristics,the variation rules of the environmental parameters in the main switchboard room 1,engine room 1,engine room 2 and corridor 2 are compared,and the variation rules of the parameters in the double-engine room under three working conditions are obtained with the change of the ventilation in the engine room under the two fire source powers.Through the comparison with the single engine room working condition,the change rule of critical time of danger in each position of single engine room and double engine room under four working conditions is obtained with the change of ventilation volume in the engine room under two fire source powers.