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Nanjing, China

Zhou R.,Nanjing University of Technology | Zhang W.,73677 PLA troops
Journal of Theoretical and Applied Information Technology | Year: 2012

In high-rise building fire, a large amount of fresh air will be pressurized into the fire floor when smoke ventilation and prevention system is used. The fresh air dilutes the smoke, but it also reduces the efficiency of mechanical exhaust. The assumption that vertical composition smoke control model (air curtain combined with pressurization and exhaust fan) is put forward. The mathematic model of smoke flow in high-rise building and κ-ε three-dimension turbulence model with two equations are used, and the influences of smoke exhaust effect with different smoke control modes are analyzed. The simulation and experiments results show that: in strip corridor, air curtain can effectively prevents the smoke moving into the atria, but the smoke control time is short relatively. While using air curtain combined with positive pressure, the smoke control time at least has an increase of 60s, and the vertical composition smoke control model has the same effect as atria pressurization model, but the volume of fresh air has decreased by 1/3. © 2005 - 2012 JATIT & LLS.All rights reserved.


Zhou R.,Nanjing University of Technology | Zhang W.,73677 PLA troops
Journal of Theoretical and Applied Information Technology | Year: 2012

In the subway station fires, the most immediate threat to passengers' life is not the direct exposure to fire, but the smoke inhalation because it contains hot air and toxic gases. Theoretical analysis and CFD simulations are applied to analyze the various possible ventilation model and obtain the optimization of ventilation mode in the subway station fires. According to the structure characters of the subway station and the mechanics analysis of smoke flowing, the air curtain is put forward to control the smoke diffusion according to the streamline and flux principle. The computational mathematical model of the air curtain is derived theoretically. The results indicate that more than 6 minutes for safe evacuation can be guaranteed by air curtain. The quantity of fresh air that the air curtain needs has been only 2/5 of which the traditional method, which effectively prevent the fire expand and control the smoke diffusion. © 2005 - 2012 JATIT & LLS. All rights reserved.


Zhou R.,Nanjing University of Technology | Zhang W.,73677 PLA troops
International Review on Computers and Software | Year: 2012

Through presenting the characters of high-rise building fire and evacuation and analyzing the faults of some evaluating methods of safe evacuation, an appropriate evaluation model, based on the overlaying of information, combining grey relational evaluation and Delphi, is established. And the relative Euclid nearness and the membership degree are used to improve the two main defects of the common grey relative model: the integrity and the relevance. Then an improved safety evaluation model was developed to obtain the safety evacuation degree and the most demanding improving factors. For getting more accurate evaluation result, Delphi is applied to obtain the weighting, which could reflect the most important factor in high-rise building fires at the present stage. Then an example is introduced to verify the feasibility of improved evaluation model. © 2012 Praise Worthy Prize S.r.l. - All rights reserved.


Zhou R.,Nanjing University of Technology | Zhou R.,State Key Laboratory of Building Safety and Built Environment | Zhang W.,73677 PLA troops | Zhao D.,Nanjing University of Technology
Research Journal of Applied Sciences, Engineering and Technology | Year: 2013

In order to control the smoke diffusing and prevent the damage to the people, the smoke temperature was researched. In high-rise building fires, the most immediate threat to passengers' life is not the direct exposure to fire but the smoke inhalation because it contains hot air and toxic gases, so it has positive meaning to find the rules of the smoke temperature distribution. The variable rule of smoke temperature field distribution in passages of highrise building was the foundation of fire fighting project. Heat-transfer process between smoke and building walls was analyzed by establishing difference equation of heat balance and diffusion process between smoke and transverse passage of high-rise building was analyzed by mathematical model of air mixed with smoke. The variable rule of smoke temperature, diffusion time and length of exit passageway was analyzed by case. Smoke temperature variation in smoke diffusion process was affected mainly by generation quantity of smoke and less affected by heattransfer process between smoke and building walls. © 2013 Maxwell Scientific Organization.

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