Simulation of Smoke Movement in a Loop Corridor under Mechanical Exhaust with Compound Model

2013 ◽  
Vol 475-476 ◽  
pp. 1459-1462
Author(s):  
Wei Shi ◽  
Fu Sheng Gao
Keyword(s):  
Field Model ◽  
Unit Area ◽  
Zone Model ◽  
Smoke Control ◽  
Smoke Movement ◽  
High Rise ◽  
Compound Model ◽  
Ceiling Height ◽  
Dynamic Simulator ◽  
Fire Dynamic Simulator

The mechanical smoke exhaust is as acknowledged as an effective smoke control manner by making use of some necessary exhaust facilities, also with more stability than natural exhaust. In this paper, the field model FDS (Fire Dynamic Simulator) with a combination of zone model CFAST (Consolidate Fire and Smoke Transport) were used to simulate the mechanical smoke exhaust in a loop corridor of the fire floor in a high-rise hotel, for the propose of evaluate fire safety of mechanical smoke exhaust. The mainly discussion was about the height of layer interface with the ceiling height changed, also with different smoke exhaust volume. The conclusions were obtained that, when two exhaust vents were set symmetrically in the loop corridor, the volume of smoke exhaust per unit area with 60m3/h according to regulations, always could ensure safety of smoke exhaust. The smoke exhausted worse within the corridor when ceiling height reduced. It was recommended that the ceiling lowest height limit should be provides in correlative regulation.

Simulating and Analyzing of Smoke Movement in a Corridor of High-Rise Building under Natural Exhaust

2013 ◽  
Vol 726-731 ◽  
pp. 3638-3641
Author(s):  
Wei Shi ◽  
Fu Sheng Gao
Keyword(s):  
Wind Speed ◽  
Leeward Side ◽  
Zone Model ◽  
Smoke Control ◽  
Smoke Movement ◽  
Additional Energy ◽  
High Rise ◽  
Smoke Layer ◽  
Dynamic Simulator ◽  
Fire Dynamic Simulator

The natural smoke exhaust is as acknowledged as a common smoke control manner, with simple form and does not require additional energy support either with the complex exhaust facilities. In this paper, the field model FDS (Fire Dynamic Simulator) with a combination of zone model CFAST (Consolidate Fire and Smoke Transport) were used to simulate the natural smoke exhaust in a straight corridor of a high-rise hotel, for the propose of evaluate fire safety of smoke exhaust. The major discussing factors are the outdoor wind direction, wind speed, et al. Height of smoke layer interface was used to evaluate the effect of smoke exhaust. The conclusions were obtained as followed. As the outdoor wind speed increases, the outdoor windows in the windward effects worse in natural smoke exhaust, but the window in the leeward side effects better.

Simulation and Analyzing of Mechanical Smoke Exhaust in a High-Rise Building

2013 ◽  
Vol 726-731 ◽  
pp. 3596-3599
Author(s):  
Wei Shi ◽  
Fu Sheng Gao
Keyword(s):  
Fire Safety ◽  
Field Model ◽  
Unit Area ◽  
Zone Model ◽  
Smoke Control ◽  
Control Manner ◽  
High Rise ◽  
High Rise Building

The mechanical smoke exhaust is as acknowledged as an effective smoke control manner by making use of some necessary exhaust facilities. In this paper, a field model with a combination of a zone model were used to simulate the mechanical smoke exhaust in a loop corridor of the fire floor in a high-rise hotel, for the propose of evaluate fire safety of mechanical smoke exhaust. There were several factors are under discussion, as the arrangement of smoke vents, quantity of smoke vents, the volume of smoke exhaust, the position of the smoke vents and height of ceiling indoor, et al. The conclusions were obtained as followed. When two exhaust vents were set symmetrically in the loop corridor, one of which was located nearby the fire room, the smoke exhausted better. The volume of smoke exhaust per unit area with 60m3/h according to regulations, always could ensure safety of smoke exhaust.

Smoke Control Models in Building Fire: A Literature Review

2012 ◽  
Vol 193-194 ◽  
pp. 1134-1137
Author(s):  
Xu Tao Zhang ◽  
Song Ling Wang
Keyword(s):  
Numerical Simulation ◽  
Field Model ◽  
Simulation Models ◽  
Analytical Models ◽  
Zone Model ◽  
Smoke Control ◽  
Smoke Movement ◽  
Building Fire ◽  
Fire Scenarios ◽  
Weak Points

The smoke control is of great importance for the life safety of the occupants in the building fire. Many analytical models have been studied for the design of smoke control. The objective of the article is to bring several numerical simulation models about building fire and smoke movement. There are generally three kinds of different models, which are net model, zone model and field model. The characteristics and weak points of each category are discussed, indicating that each model might be applicable to different building fire scenarios.

Numerical Analysis on Parameters Adjustment of Smoke Control System in a Complicated Underground Commercial Zone

2013 ◽  
Vol 341-342 ◽  
pp. 743-747
Author(s):  
De Wen Li ◽  
Jing Zhao Zhang
Keyword(s):  
Control System ◽  
Fire Spread ◽  
Smoke Control ◽  
Smoke Movement ◽  
Technical Parameters ◽  
Fire Scenarios ◽  
Dynamic Simulator ◽  
Underground Fire ◽  
Fire Dynamic Simulator ◽  
Smoke Control System

The technical parameters adjustment of smoke control system in a complicated underground commercial zone is studied by numerical simulations. An underground fire model (it encloses a hotel, a supermarket, and a net bar) and five typical fire scenarios are designed. The Fire Dynamic Simulator code is used to investigate the characteristics of fire spread and smoke movement, and obtain the available safety egress times in different fire scenarios. The required safety egress time is calculated based on the data of actual simulation exercises and numerical simulation by Building EXODUS. The simulation results show that, when the smoke exhaust rate is 5.56 cubic meter per second and air low rate reaches 3.89 cubic meter per second simultaneously, the available safety egress time is more than the required safety egress time.

Numerical Simulation of Smoke Movement in Vertical Shafts during a High-Rise Building Fire

2013 ◽  
Vol 438-439 ◽  
pp. 1824-1829
Author(s):  
Xu Tao Zhang ◽  
Song Ling Wang
Keyword(s):  
Numerical Study ◽  
Smoke Movement ◽  
Building Fire ◽  
High Rise ◽  
Smoke Flow ◽  
High Rise Building ◽  
Dynamic Simulator ◽  
Fire Dynamic Simulator ◽  
Tall Structure ◽  
Lower Opening

A numerical study on the smoke flow in a shaft, representing the stairwells, the elevator shafts and warehouses, is conducted during a high-rise building fire. It is of vital importance to predict the movement of smoke throughout the tall structure, because smoke is the major and leading cause of fatalities. The stack effect takes place due to the temperature differences between the smoke in shafts and the environment. The cold air enters in at a lower opening and exhausts at a higher ones, and this leads to the concept of the horizontal elevation called the neutral pressure plane, where the air flow equals zero. The location of neutral plane plays a key role on the management of smoke. The numeral results obtained with the FDS (Fire Dynamic Simulator) illustrate how the smoke movement can be managed in order to mitigate dangerous conditions within the structure.

Optimization of Positive Pressure Ventiliation Tactic for Wind Driven High Rise Fires

2011 ◽  
Author(s):  
Prabodh Panindre ◽  
Sunil Kumar ◽  
Atulya Narendranath ◽  
Vinay Kanive Manjunath ◽  
Venkata Pushkar Chintaluri ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Close Agreement ◽  
Positive Pressure Ventilation ◽  
Combustion Products ◽  
Positive Pressure ◽  
High Rise ◽  
Fire Scenarios ◽  
Dynamic Simulator ◽  
Fire Dynamic Simulator ◽  
Fire Location

Positive Pressure Ventilation (PPV) is a firefighting tactic that can mitigate the spread of fire and the combustion products to improve the safety of firefighters and civilians in wind-driven high-rise fires than without PPV. The performance of a PPV tactic in wind-driven high-rise fires depends on various parameters that include wind speed, control of stairwell doors, number of fans, fan positions and placements, fire location etc. This paper describes the influence of these parameters on the efficacy of PPV operation that was studied by simulating wind-driven high-rise fire scenarios using computational fluid dynamics softwares Fluent 12.0 and NIST’s Fire dynamic simulator (FDS 5.0). The results obtained from Fluent and FDS found to be in close agreement with each other and have been used to optimize the PPV operation for better performance.

Numerical Investigation of Fire Dynamic Behavior for a Commercial Building Basement

2012 ◽  
Vol 594-597 ◽  
pp. 2213-2218 ◽  
Author(s):  
Cherng Shing Lin ◽  
Chia Chun Yu ◽  
Shih Cheng Wang
Keyword(s):  
Fire Protection ◽  
Computer Simulation Model ◽  
Commercial Building ◽  
Smoke Movement ◽  
Building Fire ◽  
Fire Disaster ◽  
Fire Smoke ◽  
Dynamic Simulator ◽  
Fire Dynamic Simulator ◽  
Property Losses

In the past twenty years, many severe basement fires occurred and caused huge losses of human lives and damages to property in Taiwan. During a building fire, smoke at high temperatures and poisonous gases (such as CO) may easily spread through corridors and ventilation systems in the entire building. Therefore, protecting against the basement fires in commercial buildings is of important concern for Taiwan’s fire protection authority. This paper utilizes FDS (Fire Dynamic Simulator) to construct a computer simulation model for investigating the Cardon basement fire that occurred in Taipei (1993). The fire accident unfortunately caused tremendous property losses and heavy casualties (22 died and 7 were injured). The major important parameters of the flow field - such as speed to the spread of fire, smoke movement, upper layer temperature, and CO concentration are obtained to analyze and understand the fire dynamic characteristics. The computed results reasonably agree with post-accident reports. The simulation results obtained may be utilized to improve the better and safer designs for basement building fire protection capability. The information can also be valuable for the similar fire disaster prevention and mitigation in the future.

PPV Effect on Smoke Movement Through a Shaft in High-Rise Fires: Experiments and CFD Simulation

2019 ◽  
Author(s):  
Xiaoman Ye ◽  
Ofodike A. Ezekoye ◽  
Qize He
Keyword(s):  
Positive Pressure Ventilation ◽  
Cfd Simulation ◽  
Positive Pressure ◽  
Gas Temperature ◽  
Air Flow Rate ◽  
Smoke Control ◽  
Smoke Movement ◽  
Cfd Simulations ◽  
High Rise ◽  
Reduced Scale

Abstract While Positive Pressure Ventilation (PPV) has proven to be effective in high-rise fire-fighting, its effect on smoke movement through a stairwell shafts in high-rise fires is still inconclusive. Towards better understanding of the effects of PPV for smoke transport in high-rise type structures, a 1/4 reduced-scale 7-floor building with dimensions of 1.0 m × 0.5 m × 4.2 m consisting of a vertical shaft and several rooms over a number of floors has been designed and tested. Both experiments and CFD simulations for this model were conducted. It was found that there are several potential PPV tactics that could be useful in high-rise smoke control in fires. In the cases examined, PPV was considered to be applied from outside the building through vents in external rooms of the building. When a PPV fan is applied above the floor containing the fire layer, the pressure induced by the PPV flow should be larger than the pressure difference caused by the stack effect induced by the hot fire product gases. Insufficient PPV flow rates is shown to lead to accumulation of smoke and further increase in the gas temperature within the shaft due to the blocking effect. A better option is applying PPV below the fire floor. With the same pressurization air flow rate, applying PPV from below the fire floor is more effective than applying it from the top of building. In this situation, PPV not only prevents accumulation of the smoke in the shaft, but also prevents smoke from entering the shaft. The results of this study can guide the development of firefighter ventilation tactics for smoke control in high-rise fires.

Effects of Exit Vent Location on Fire Room Conditions During PPV

2008 ◽  
Author(s):  
Colin M. Beal ◽  
Ofodike A. Ezekoye
Keyword(s):  
Positive Pressure ◽  
Computational Simulations ◽  
Cold Flow ◽  
Flow Simulations ◽  
Advantages And Disadvantages ◽  
Experimental Compartment ◽  
Dynamic Simulator ◽  
Fire Dynamic Simulator ◽  
Hot Products ◽  
Vent Location

Positive Pressure Ventilation (PPV) is a widely used fire fighting tactic in which a fan is used to push hot products of fire out of a burning structure. There is a recent body of research that has been conducted regarding the advantages and disadvantages of PPV. Studies of PPV most commonly use full scale experimental fires and/or computational simulations to evaluate its effectiveness. This paper presents computational simulations that have been conducted using Fire Dynamic Simulator (FDS) version 5 to evaluate the effects of exit vent location on resulting fire room conditions during the application of PPV to a ventilation constrained fire. The simulations use a simple one room structure with an adjacent hallway. We are simulating this geometry because we are in the process of designing and constructing a similar experimental compartment. Cold flow simulations are first conducted to understand how much the presence of the fire heat release affects the flow patterns. Then, two simulations which employ PPV with different exit vent locations are compared. The differences between the two simulations are detailed and a physical explanation for the differences is presented.

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