Numerical Analysis on the Effect of Thermal Insulation of Closure on Fire Smoke Spread Rate in Building's Corridor

2014 ◽  
Vol 513-517 ◽  
pp. 2635-2638
Author(s):  
Xuan Wei Peng
Keyword(s):  
Numerical Analysis ◽  
Thermal Insulation ◽  
Air Temperature ◽  
Spread Rate ◽  
Smoke Flow ◽  
External Insulation ◽  
Flow Prediction ◽  
Smoke Spread ◽  
Fire Smoke ◽  
Fire Ignition

The corridor is an important way of evacuation and rescue in building fire. The fire smoke flow prediction software developed successfully was applied to simulate a building with a 28.8 meters long corridor to investigate the effect of the different thermal insulation on fire smoke spread rate. Two representative thermal insulation, external insulation and internal insulation were compared. In 3600s fire time, air temperature in the corridor of external insulation is much lower than that of internal insulation. The air temperature gap gets narrowed between the two insulation methods in the corridor with the prolongation of fire time. Temperature difference increases as the distance increase from the fire ignition place. The corridor gets unsafe of internal insulation in 7 minute since fire ignition, while about half the length of the corridor stay secure of external insulation in 10 minutes since fire ignition. That implies more available safe egress time can be gained with external insulation than internal insulation. Smoke spread rate was numerically compared based on the air temperature variation. Smoke spread rate of internal insulation is much higher than that of external insulation and the corresponding ratio is 1.732:1.

Numerical Analysis on the Influence of Thermal Insulation Way of Closure on Smoke Flow Properties in Building Fire

2013 ◽  
Vol 353-356 ◽  
pp. 3020-3024
Author(s):  
Xuan Wei Peng
Keyword(s):  
Indoor Air ◽  
Room Temperature ◽  
Cooling Effect ◽  
Flow Properties ◽  
Smoke Flow ◽  
External Insulation ◽  
Flow Prediction ◽  
Wall Structures ◽  
Fire Smoke ◽  
In Fire

The fire smoke flow prediction software developed successfully was applied to simulate a simple building. The effect of different wall structures on the fire smoke flow properties were compared under the condition of same thermal resistance of external wall. Heat absorption of wall has a cooling effect on indoor air in fire process. Wall with external insulation has the most significant cooling effect on indoor air, and that with internal insulation has the weakest. The effect of intermediate insulation is close to external insulation and that of bilateral insulation close to internal insulation. Room temperature and smoke concentration of internal insulation are both higher markedly than of external insulation. The effect of intermediate insulation is close to external insulation and bilateral insulation close to internal insulation. External insulation added to the closure helps to cool indoor air in the fire process. Intermediate insulation should be chosen to add to the inner wall when needed because of the uncertainty of fire location.

Study of Fire Smoke Flow of Tunnel at Different Longitudinal Ventilation

2012 ◽  
Vol 226-228 ◽  
pp. 1472-1475
Author(s):  
Pei Pei Yang ◽  
Xiao Lu Shi ◽  
Bi Ming Shi
Keyword(s):  
Flow Resistance ◽  
Reverse Flow ◽  
Ventilation System ◽  
Gas Temperature ◽  
Smoke Control ◽  
Smoke Flow ◽  
Longitudinal Ventilation ◽  
Smoke Spread ◽  
Fire Smoke ◽  
Safety Evacuation

Once the tunnel fires happened, it will cause a major accident. And the smoke control of the runnel is important to fire prevention. A numerical simulation of the fire smoke flow in the tunnel model is presented by using FDS. The influence of different longitudinal ventilation on fire smoke flow of tunnel is obtained. And providing theory basis for tunnel ventilation system design, smoke spread control and safety evacuation. The results shown that in order to avoid reverse-flow and extend the time of smoke at the top of tunnel, the longitudinal speed should be controlled in 3.4 m/s; because of the role of longitudinal ventilation, smoke flow resistance and longitudinal ventilation generated by the effect of smoke flow resistance make the gas temperature first rise and then down.

scholarly journals Effects of Fire Compartmentation and Smoke Exhaust Measures on Smoke Spread Caused by Cable Fire in Utility Tunnel

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Li Xin ◽  
Zhang Yuanyuan ◽  
Jia Boyan ◽  
Zhang Guowei ◽  
Zheng Li
Keyword(s):  
Prevention And Control ◽  
Simulation Software ◽  
Normal Operation ◽  
Spread Rate ◽  
Smoke Spread ◽  
Fire Smoke ◽  
Utility Tunnel ◽  
Smoke Prevention ◽  
And Control ◽  
Fire Door

Investigating the behavior of fire smoke in utility tunnel as well as smoke prevention and control measures are of vital significance for exhausting smoke from utility tunnel, realizing efficient firefighting and rescue, and guaranteeing the normal operation of cities. Taking utility tunnel as the research background, this paper builds a simulation calculation model for fire smoke prevention and control in the utility tunnel using PyroSim numerical simulation software and explores the rules of smoke spread under conditions such as building ceiling screen, changing fire compartmentation tightness, and adding smoke exhaust facilities. According to study results, before the tunnel was filled with smoke, ceiling screens lowered smoke spread rate, and smoke spread rate was inversely proportional to the ceiling screen height. When the fire door was opened, fire smoke spread to the adjacent fire compartment, and smoke spread rate was directly proportional to the fire door opening angle. Before the tunnel was filled up, mechanical smoke exhaust facilities significantly lowered the smoke spread rate by as much as 50%. When the entire tunnel was full of smoke, mechanical smoke exhaust facilities significantly reduced the smoke concentration in the utility tunnel; smoke layer temperature dropped by as much as 32°C, while visibility improved by as much as 66%. By studying smoke spread in utility tunnel, this paper aims to determine the optimal measures of preventing and controlling smoke spread in utility tunnel. This paper could also offer some reference for practical engineering applications in smoke prevention and control in utility tunnel.

scholarly journals Numerical Analysis for Smoke Spread in an Aircraft Hangar

2019 ◽  
Vol 111 ◽  
pp. 01090
Author(s):  
Essam E. Khalil ◽  
Hatem Kayed Haridy ◽  
Eslam Said Abdelghany Ahmed ◽  
Ahmed Ashraf Mohamed
Keyword(s):  
Numerical Analysis ◽  
Ventilation System ◽  
Spread Rate ◽  
Air Velocity ◽  
Supply Rate ◽  
Traditional System ◽  
Smoke Spread ◽  
Dynamic Simulator ◽  
Fire Dynamic Simulator ◽  
Evacuation Plan

Smoke is one of the most dangerous factors in aircraft hangar in case of fire. As it causes reduce in visibility and deaths due to high temperature or toxicity also prevents applying evacuation plan for workers. This study present numerical analysis for improving traditional system of ventilation system to manage smoke produced due to push-back vehicle on fire at hangar. By studying effect of changing extraction and supply rates, the number of extraction and supply fans, and the arrangement of extraction and supply fans on the visibility, temperature and air velocity at human level to insure not to exceed limits stated by NFPA 130[1] to apply evacuation plan for workers. The study is performed using Fire dynamic simulator to simulate 16 case studies in the hangar of airports in Brandenburg. The hangar has the outer dimensions of 83.40 m width and 77.60 m depth and thus an inner area of approx. 6,472 m2. The hangar has a medium interior height of approximately 18.20 m. The results show that using extraction fans with rate (ACH) double the supply rate for the traditional ventilation system gives very good results in controlling the smoke. As well as, decreasing the number of supply fans will make the smoke spread rate inside the hangar lower, which helps to control the smoke spread of fire in less time.

Study on transient heat transfer through multilayer thermal insulation: Numerical analysis and experimental investigation

2010 ◽  
Vol 3 (4) ◽  
pp. 279-294 ◽  
Author(s):  
Lazaros Elias Mavromatidis ◽  
Pierre Michel ◽  
Mohamed El Mankibi ◽  
Mat Santamouris
Keyword(s):  
Heat Transfer ◽  
Experimental Investigation ◽  
Numerical Analysis ◽  
Thermal Insulation ◽  
Transient Heat Transfer

Empirical Formula Considering the Smoke Ventilation for Air Temperature in Large Space Structure under Fire

2011 ◽  
Vol 94-96 ◽  
pp. 587-593 ◽  
Author(s):  
Jin Liang ◽  
Su Duo Xue ◽  
Xiong Yan Li
Keyword(s):  
Air Temperature ◽  
Empirical Formula ◽  
Steel Structures ◽  
Space Structure ◽  
Space Structures ◽  
Large Space ◽  
Fire Temperature ◽  
Large Space Structure ◽  
Fire Smoke ◽  
Resistance Performance

Abstract.The fire smoke is one of the most important factors for the fire temperature field. Once the fire smoke has been exhausted effectively, the fire temperature will be reduced and the fire-resistance performance of steel structures may be improved as well. However, the research on the fire temperature in the space structures is almost bold, which could lead to the theoretical analysis result on fire temperature is quite different from the real condition. Accordingly, the air temperature condition on fire for large-space structures has been analyzed. Taken into account smoke ventilation, the empirical formula for air temperature in large space structure under fire has been modified.

scholarly journals Numerical analysis of thermal insulation performance of horizontal LNG cylinder

2018 ◽  
Vol 452 ◽  
pp. 022084
Author(s):  
Ping Tang ◽  
Min Wang ◽  
Zhangwei Ling ◽  
Zhengpei Jiang ◽  
Xiaolian Guo ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Thermal Insulation ◽  
Insulation Performance

scholarly journals Investigation of the Insulation Effect of Thermal Insulation Layer in the Seasonally Frozen Region Tunnel: A Case Study in the Zuomutai Tunnel, China

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Pengyu Zhao ◽  
Jianxun Chen ◽  
Yanbin Luo ◽  
Lijun Chen ◽  
Yao Li ◽  
...  
Keyword(s):  
Thermal Insulation ◽  
Air Temperature ◽  
Ground Surface ◽  
Maximum Temperature ◽  
Insulation Layer ◽  
Tunnel Length ◽  
Maximum Temperature Difference ◽  
Insulation Effect ◽  
Two Sides

In this study, a field temperature test was performed to reveal the insulation effect of the thermal insulation layer installed at lining surface. The thermal insulation layer is made of polyphenolic, and the thickness is 7 cm. According to the test results, the temperature of the thermal insulation layer and lining continuously changes with the air temperature in the tunnel in an approximately trigonometric function. The temperature of tunnel lining without thermal insulation layer is close to the air temperature, which results in the lining frost in winter. The maximum temperature difference between the two sides of the thermal insulation layer can be 27°C. In the section whose buried depth is more than 11.4 m, the temperature of lining with thermal insulation layer in winter is mainly influenced by the cold air in the tunnel. When the monthly mean and lowest daily mean air temperature are lower than −10°C and −14.3°C in the coldest month, the temperature at the inner side of the thermal insulation layer is below 0°C. When the buried depth is less than 11.4 m, the temperature of lining is also influenced by the low temperature at ground surface. The temperature of lining is lower. The thicker thermal insulation layer and even active heat measure are needed. Therefore, the design of thermal insulation layer thickness should consider the air temperature distribution and tunnel buried depth along the tunnel length.

Numerical analysis of thermal insulation in a cold box of cold neutron source system

2010 ◽  
Author(s):  
F. Yu ◽  
Y. Z. Li ◽  
Y. H. Zhu ◽  
Liejin Guo ◽  
D. D. Joseph ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Neutron Source ◽  
Thermal Insulation ◽  
Cold Neutron ◽  
Cold Neutron Source ◽  
Cold Box
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