Analysis of jet fan ventilation system and optimization of fan installation in underground car park with using computational fluid dynamics

With the development of cities and increasing population, the need for underground car parks has increased. When the fire protection policies of these buildings are taken into consideration, smoke and heat transport becomes important. The Fire Dynamics Simulator (FDS) is a large eddy simulation (LES) code for low-speed flows, with emphasis on the transport of smoke and heat from fires. Analyze Navier-Stokes equations by considering velocity and temperature equations. Flow area was analyzed using Large Eddy Simulation (LES) turbulence modeling. The fire dynamics simulator is used to investigate fire propagation and smoke movement in a large underground parking lot under different fire scenarios. In this study, it was initially designed by comparing the car's fire development by allowing the surface densities of the fuel on the vehicle, comparing the experimental results of the heat release rate of a single automobile fire. Fire propagation and movement of smoke are then investigated under different ventilation conditions. In addition, detailed field distributions of velocity vectors, temperature, carbon monoxide gas content and visibility are given. In this study, simulation results are presented by using Pyrosim software for forced mechanical horizontal ventilation and smoke and heat control (DIK) in case of fire in the parking lot. The effects of the number of hourly air changes of the indoor parking volume on the results were also examined. In the analysis with radial jet fan and 10 air exchange, velocity at the escape point was 0,9154 m/s, temperature was 40,13°C, visibility was 3 m and CO gas level was 71,5 ppm.In the analysis with radial jet fans and 15 air-exchanges, the velocity at the escape point was 1,324 m / s, temperature was 29,98°C, visibility was 30 m and CO gas level was 1 ppm. In the analysis with axial jet fan and 10 air changes, the velocity at the escape point was 0,9176 m/s, the temperature was 38,02°C, the visibility was 3 m and the CO gas level was 61,5 ppm. In the analysis with axial jet fan and 15 air exchange, velocity at the escape point was 1,318 m/s, temperature was 28,15°C, visibility was 30 m and CO gas level was 1 ppm.In order to guarantee fire safety in large underground car park systems, it is necessary to study in detail the spread of fire and the movement of smoke. In our country, there is no smoke control standard for propulsion ventilation systems in closed parking lots. Using a jet fan ventilation system, the impulse ventilation system in underground parking lots can be designed experimentally or using computational fluid dynamics technique. The computational fluid dynamics technique is the best and most cost-effective when considering the available computer technology in the design of this system.