On the Optimization of Vent Arrangement in a Subway Station

2012 ◽  
Vol 232 ◽  
pp. 620-624
Author(s):  
Atta Sojoudi ◽  
Farbod Vakilimoghaddam ◽  
Reihaneh Neishapouri
Keyword(s):  
High Temperature ◽  
Exhaust System ◽  
Subway Station ◽  
Volume Flux ◽  
Toxic Gases ◽  
Fire Smoke ◽  
Temperature Radiation

Toxic gases resulted from fire events in subways stations are more dangerous than high temperature radiation from it. So, a well designed smoke exhaust system must be installed in subway station to control the smoke’s propagation and discharging. Smoke extraction in subway station depends on the duct laid above the ceiling, so vents are situated in the same level of platform layer’s ceiling. If subway station catches fire, smoke will cumulate in smoke reservoirs at the beginning and mechanical fan cannot exhaust any smoke in this process. In This paper, FDS 5.0 is used to simulate smoke’s movement in a side platform of an actual subway station in case of a fire. Simulations are carried out at the same volume flux of mechanical fan to investigate the effects of height of vents and depth of smoke reservoirs.

scholarly journals A STUDY OF THE FIRE SMOKE PROPAGATION IN SUBWAY STATION UNDER THE EFFECT OF PISTON WIND

2015 ◽  
Vol 21 (4) ◽  
pp. 514-523 ◽  
Author(s):  
Wei Zhong ◽  
Rui Tu ◽  
Jian Peng Yang ◽  
Tian Shui Liang
Keyword(s):  
Wind Tunnel ◽  
Large Scale ◽  
Inertial Force ◽  
Field Structure ◽  
Subway Station ◽  
Volume Flux ◽  
Ventilation Shaft ◽  
Fire Smoke ◽  
In Fire ◽  
The Impact

A running traffic train induces piston wind in the subway. The influence of piston wind on fire smoke propagation in subway is investigated numerically. The flow field structure in fire platform, temperature contours and velocity profiles at certain positions are obtained at various scenarios respectively. Three methods are adopted to reduce the impact of piston wind on smoke layers. Results show that large-scale vortexes and tremendous horizontal inertial force would be produced under the influence of piston wind; and that smoke stratification would be broken totally under its influence, therefore toxic gas would spread to subway hall through stairs. So the former smoke management system in a subway station becomes less effective. Results also show that combination of enhanced the volume flux of pressurization at the subway hall and lowering the height of smoke screens around stairs are necessary to restrict hazard smoke on the floor on fire. The bypass wind tunnel and ventilation shaft are useful to attenuate the magnitude of piston wind.

ATI 441 ALLOY

Alloy Digest ◽  
2013 ◽  
Vol 62 (7) ◽  
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
Exhaust System ◽  
Low Carbon ◽  
Temperature Performance ◽  
System Components ◽  
Low Nitrogen

Abstract ATI 441 is a low-carbon and low-nitrogen ferritic stainless steel with 18 Cr and columbium. The alloy is typically used for exhaust system components. This datasheet provides information on composition, physical properties, hardness, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as forming. Filing Code: SS-1150. Producer or source: Allegheny Technologies Inc..

REMANIT 4509

Alloy Digest ◽  
1995 ◽  
Vol 44 (9) ◽  
Keyword(s):  
Corrosion Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
Exhaust System ◽  
Heat Treating ◽  
Exhaust Gas ◽  
Gas Purification ◽  
Temperature Performance ◽  
Scale Resistance ◽  
High Degree

Abstract REMANIT 4509 was developed specially for silencers and exhaust gas purification plants. Due to its composition, this steel exhibits scale resistance up to 950 C and a high degree of corrosion resistance to the gases occurring in the exhaust system. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, and joining. Filing Code: SS-613. Producer or source: Thyssen Stahl AG.

INCOLOY ALLOY 864

Alloy Digest ◽  
1998 ◽  
Vol 47 (2) ◽  
Keyword(s):  
Corrosion Resistance ◽  
High Temperature ◽  
Mechanical Strength ◽  
High Performance ◽  
Exhaust System ◽  
Good Combination ◽  
Fatigue Properties ◽  
Temperature Performance ◽  
Incoloy Alloy ◽  
Oxidation And Corrosion

Abstract Incoloy Alloy 864 is a high performance alloy developed specifically for automotive exhaust system flexible couplings and other exhaust applications. The alloy has a good combination of oxidation and corrosion resistance, with good mechanical strength, stability, and fatigue properties. This datasheet provides information on composition, physical properties, and elasticity. It also includes information on high temperature performance and corrosion resistance as well as joining. Filing Code: SS-708. Producer or source: Inco Alloys International Inc.

Heat Resistance of Ferritic Stainless Steels with 15% Chromium for Automobile Exhaust System

2011 ◽  
Vol 239-242 ◽  
pp. 1799-1803
Author(s):  
Hua Bing Li ◽  
Zhou Hua Jiang ◽  
Qi Feng Ma ◽  
Dong Ping Zhan
Keyword(s):  
High Temperature ◽  
Grain Boundaries ◽  
Thermal Fatigue ◽  
Fatigue Cracks ◽  
Exhaust System ◽  
High Temperature Strength ◽  
Temperature Oxidation ◽  
Ferritic Stainless Steels ◽  
Automobile Exhaust ◽  
Thermal Fatigue Cracks

The high-temperature strength and thermal fatigue properties of Fe-Cr-Nb-Mo ferritic stainless steel (FSSNEW) developed for automobile exhaust system were investigated. The results show that the high-temperature tensile strength and yield strength of FSSNEW are better than or equal to those of the presently applied ferritic stainless steels. The thermal fatigue cracks nucleate at the V-notch. The inclusions along grain boundaries become prior regions for initiation of the cracks. The inclusions distributed at the defects make the formation of cracks in the materials easily through the effects of cycle thermal stress and thermal strain. The length and propagated rate of thermal fatigue cracks increase with the maximum tested temperature increasing. When the maximum temperature arrives at 900°C, the high-temperature oxidation is serious along the grain boundaries, which aggravates the cracks propagating along the grain boundaries. The principle mechanism of stress assisted grain boundary oxygen (SAGBO) embrittlement can be applied to illustrate the effects of external stress on aggravating the damage caused by environmental factors. Therefore, the high-temperature oxidation is the main reason for the propagation of thermal fatigue cracks. The FSSNEW is satisfied for the applied requirement of high-temperature strength in the hot side of the automobile exhaust system.

High temperature / radiation hardened capable ARM® Cortex®-M0 microcontrollers

2016 ◽  
Vol 2016 (HiTEC) ◽  
pp. 000046-000050
Author(s):  
R. Bannatyne ◽  
D. Gifford ◽  
K. Klein ◽  
C. Merritt
Keyword(s):  
High Temperature ◽  
Lower Cost ◽  
Cmos Technology ◽  
The Other ◽  
Device Performance ◽  
High Radiation ◽  
Plastic Package ◽  
Radiation Hardened ◽  
Temperature Radiation ◽  
On Chip

Abstract VORAGO Technologies has developed a pair of ARM Cortex M0 MCUs designed from the ground up to be high temperature capable. One of these devices is specifically developed for high temperature applications, the other adds capabilities that make it suitable for use in high radiation environments as well. These devices are fabricated using a modified version of commercial bulk 130nm CMOS technology utilizing our HARDSIL® technology, which provides immunity to the increased effects of latchup and EOS encountered at higher application temperatures. In addition to the processor these devices include features more typical of low temperature SoCs including on-chip memory, timers, and communications peripherals. In addition to the ceramic package and die format typically utilized at high temperature, a new lower-cost plastic package is available that has been characterized at higher temperatures. These devices have been characterized at temperatures up to 200C and results showing the latchup behavior and device performance are provided. Some of the tradeoffs involved in creating such devices are discussed, as well as some of the similarities and tradeoffs in creating a radiation hardened devices vs. a high temperature device.

Establishment of narrow spectral band model parameters database for gas high temperature radiation characteristics

2017 ◽  
Vol 46 (7) ◽  
pp. 704001
Author(s):  
蔡红华 Cai Honghua ◽  
聂万胜 Nie Wansheng ◽  
吴 睿 Wu Rui ◽  
苏凌宇 Su Lingyu ◽  
侯志勇 Hou Zhiyong
Keyword(s):  
High Temperature ◽  
Spectral Band ◽  
Model Parameters ◽  
Band Model ◽  
Radiation Characteristics ◽  
Narrow Spectral Band ◽  
Temperature Radiation
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