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of another system, especially a computer program designed for that purpose
CFD Projects
CAE Projects
Customized Software Tools
World Trade Center - Doha
Car park Ventilation Design
Figure showing the 3D model of the Car Park basement With Two cars
Figure showing the Spreading of Smoke in the Basement.
Figure showing the Temperature Level in the Basement
Results and Conclusion
a) The First Analysis was carried out with 2 cars burning at the HRR provided by the client without any ventilation system and it was found that the temperature rose up to 80 degrees at human height inside the basement and the smoke spread all over the basement causing poor visibility.
b) The second analysis was carried out by considering the fans operating at high speed and no jet fans and it was simulated for 33.6 minutes. It was found that the temperature was 60 degrees at human height and the visibility level was up to 4 meters at peak heat release rate.
c) The third analysis was carried out with all the ventilation system operating at high speed and was simulated for 25.6 minutes of duration with cars burning based on fire heat release rate as provided. It was found that the temperature was not exceeding 60 degrees outside the fire region at human height ( 1.8 meters) and the visibility at the back side of the fire was more than 5 meters which is comparatively better than the other cases. Thus, it was concluded that the ventilation system will work effectively and efficiently in emergency conditions.
Objective
The objective of the present work is to examine the designed ventilation system for the car parking basement of “World Trade Center - Doha” Project using CFD analysis. The specific aim of the project is to compare the fire simulation analysis of jet fan ventilation system, without jet fan ventilation system and without mechanical ventilation systems, for the given positions of supply air openings, exhaust openings, jet fans and car fire location, and given configuration of all the ventilation fans & intensity of the fire. Fire safety in underground basements is very important, as accidental fires can be dangerous. When a fire breaks out in an underground basement, a large amount of smoke is generated at high temperature leading to poor visibility and difficulty in evacuation. In most cases, the victims are poisoned or starved of oxygen by the smoke. In addition, the smoke also causes damage to other vehicles parked inside the underground basement car parking area.
Modeling and Analysis
From the CAD detail provided by the client a 3D model of the basement levels was modeled. In this work the fire is modeled with a heat release rate of 3 MW in the beginning. And after 5 minutes it was considered with two cars burning with a maximum heat release rate of 6 MW. In this work, as per the client requirement three fire simulations were carried out. The first one is without mechanical ventilation systems, second one is without jet fans and the third one is with jet fans. In the last two fire simulations all the exhaust fans & supply fans are running in high speed as per the fan specifications. Simulation of smoke propagation inside a basement involves modeling of heat generation by fire, effects of buoyancy due to temperature and smoke species concentrations and the velocity and pressure variations caused by jet fans in operation. CFD analysis provides a detailed picture of the smoke path inside the basement and different parameters like smoke concentrations, smoke temperatures, velocity profiles and visibilities at different times and different positions inside the basement.
