The volumetric flow rate of smoke generated from the fire in large space often reaches to hundreds of thousands CMH because of extended floor height and as it’s more difficult to isolate the smoke to the limited area...The volumetric flow rate of smoke generated from the fire in large space often reaches to hundreds of thousands CMH because of extended floor height and as it’s more difficult to isolate the smoke to the limited area, comparing to normal-scale building, design and operation of effective smoke control system for large space is more than important. In this study, with the analysis model for such a large space as exhibition hall or conference room in conventional center, design of mechanical smoke exhaust system was conducted based on currently-available design standard which was then followed by numerical analysis of the design using 3D numerical analysis method. For conference room at 2.0 MW heat release rate, 99,173 CMH flow rate is required, if smoke layer is maintained at 60% of the floor height and for exhibition hall at 8.8 MW with 80% of floor height, flow rate required is 219,802 CMH, which are incorporated into the design. In view of 3D numerical analysis, accuracy of the design according to algebraic expression is sufficient.展开更多
Death toll by smoke in fire is estimated at 70% which emphasizes the importance of smoke control system to deal with the fire smoke. In advanced countries, the studies on method to prevent smoke spread by forming the ...Death toll by smoke in fire is estimated at 70% which emphasizes the importance of smoke control system to deal with the fire smoke. In advanced countries, the studies on method to prevent smoke spread by forming the air curtain using high velocity jet flow are underway now. In this study, a linear-jet type air curtain system is proposed to prevent the smoke spread and analysis of flow characteristics of pressure chamber, which is the core component, is conducted through numerical analysis and experimental approach. Consequently, the pressure was increased in 2D functional way to input air flowrate and about 595 Pa pressure was formed at pressure chamber inlet in response to 30 m/s nozzle jet velocity.展开更多
In houses and general buildings of environment where smoke control equipment is not installed, or its operation is difficult, there is a need to develop and utilize a portable smoke exhaust fan that can perform emerge...In houses and general buildings of environment where smoke control equipment is not installed, or its operation is difficult, there is a need to develop and utilize a portable smoke exhaust fan that can perform emergency ventilation in case of fire suppression and rescue operations. As a part of the development process for portable smoke exhaust fans, a numerical analysis model of the portable smoke exhaust fan was derived from the building in which a fire occurred, and an analysis on the smoke and toxic gas exhaust effects was performed in this study. The numerical analysis results showed that under a condition where the height of an opening is less than 1.0 m after fire source disappears in a situation where the smoke exhaust fan does not operate, smoke does not come out well, and thus the density of smoke within the target area does not drop significantly. On the other hand, if the smoke exhaust fan operates after the fire source disappears, smoke is directly exhausted to the outside due to the operation of the smoke exhaust fan, and the smoke density within the space drops sharply in all opening height conditions, thereby getting close to zero.展开更多
文摘The volumetric flow rate of smoke generated from the fire in large space often reaches to hundreds of thousands CMH because of extended floor height and as it’s more difficult to isolate the smoke to the limited area, comparing to normal-scale building, design and operation of effective smoke control system for large space is more than important. In this study, with the analysis model for such a large space as exhibition hall or conference room in conventional center, design of mechanical smoke exhaust system was conducted based on currently-available design standard which was then followed by numerical analysis of the design using 3D numerical analysis method. For conference room at 2.0 MW heat release rate, 99,173 CMH flow rate is required, if smoke layer is maintained at 60% of the floor height and for exhibition hall at 8.8 MW with 80% of floor height, flow rate required is 219,802 CMH, which are incorporated into the design. In view of 3D numerical analysis, accuracy of the design according to algebraic expression is sufficient.
文摘Death toll by smoke in fire is estimated at 70% which emphasizes the importance of smoke control system to deal with the fire smoke. In advanced countries, the studies on method to prevent smoke spread by forming the air curtain using high velocity jet flow are underway now. In this study, a linear-jet type air curtain system is proposed to prevent the smoke spread and analysis of flow characteristics of pressure chamber, which is the core component, is conducted through numerical analysis and experimental approach. Consequently, the pressure was increased in 2D functional way to input air flowrate and about 595 Pa pressure was formed at pressure chamber inlet in response to 30 m/s nozzle jet velocity.
文摘In houses and general buildings of environment where smoke control equipment is not installed, or its operation is difficult, there is a need to develop and utilize a portable smoke exhaust fan that can perform emergency ventilation in case of fire suppression and rescue operations. As a part of the development process for portable smoke exhaust fans, a numerical analysis model of the portable smoke exhaust fan was derived from the building in which a fire occurred, and an analysis on the smoke and toxic gas exhaust effects was performed in this study. The numerical analysis results showed that under a condition where the height of an opening is less than 1.0 m after fire source disappears in a situation where the smoke exhaust fan does not operate, smoke does not come out well, and thus the density of smoke within the target area does not drop significantly. On the other hand, if the smoke exhaust fan operates after the fire source disappears, smoke is directly exhausted to the outside due to the operation of the smoke exhaust fan, and the smoke density within the space drops sharply in all opening height conditions, thereby getting close to zero.
