scholarly journals Determination of smoke layer thickness using vertical temperature distribution in tunnel fires under natural ventilation

2022 ◽  
Vol 119 ◽  
pp. 104257
Author(s):  
Aoi Tanno ◽  
Hideyuki Oka ◽  
Kyoko Kamiya ◽  
Yasushi Oka
Keyword(s):  
Temperature Distribution ◽  
Layer Thickness ◽  
Natural Ventilation ◽  
Vertical Temperature ◽  
Tunnel Fires ◽  
Smoke Layer ◽  
Vertical Temperature Distribution

Prediction of the Vertical Temperature Distribution in a Large Enclosure Under Combined Air Conditioning and Natural Ventilation

Solar Energy ◽  
2004 ◽  
Author(s):  
Jun Gao ◽  
Xiao-Dong Li ◽  
Jia-Ning Zhao ◽  
Fu-Sheng Gao
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Air Temperature ◽  
Air Conditioning ◽  
Natural Ventilation ◽  
Vertical Temperature ◽  
Combined System ◽  
Efficient System ◽  
Macro Scale ◽  
Vertical Temperature Distribution

This paper describes a combined system of air conditioning and natural ventilation for large enclosures. A multi-zonal model to simulate the vertical temperature distribution is established. This model describes airflow and heat transfer on a ‘macro’ scale compared to CFD model, but it appears very efficient for engineering application. In this model, air density is considered to change with air temperature. Multiple air jets, buoyancy driven natural ventilation and coupled heat transfer are taken into consideration. It is governed by non-linear equations and is resolved by an iterative solution. A program is compiled to calculate the mass flow and temperature distributions. It shows that the combined system of air conditioning and natural ventilation cut considerably down heat gain in occupied zone. By comparison, the combined system can be expected to give lower temperature both in the enclosure and on interior surfaces. Some cases are calculated, and the results suggest that it depends on many factors such as the height of ventilating opening, the effective opening area, and outdoor air temperature to effectively make use of natural ventilation in the combined system. To sum up, this paper presents an energy efficient system for large spaces and also a theoretical model to design the system and predict the vertical temperature distribution.

scholarly journals Experimental study on the smoke temperature distribution alongside the lining in tunnel fires

2019 ◽  
Vol 23 (6 Part A) ◽  
pp. 3701-3710 ◽  
Author(s):  
Feng Wang ◽  
Yu Wang ◽  
Yubing Huang ◽  
Qixiang Yan
Keyword(s):  
Temperature Distribution ◽  
Structural Safety ◽  
Small Scale ◽  
Pool Fires ◽  
Test Results ◽  
Vertical Temperature ◽  
Tunnel Fires ◽  
Tunnel Fire ◽  
Key Factor ◽  
Vertical Temperature Distribution

Tunnel fire temperature is a key factor for tunnel structural safety and evacuation. This study aimed to investigate the smoke temperature distribution alongside the lining across the section and effects of pool sizes and fuels on it through a series of small-scale experiments. The results showed the heat release rates of diesel were significantly lower than gasoline?s when they had the same pool size and volume. Nevertheless, the duration of diesel combustion increased obviously. As a result, the maximum smoke temperature under the ceiling for gasoline was significantly higher than diesel?s. The results were subsequently adopted to compare with other test results and illustrated a similar result. The initial temperature rising rates for gasoline pool fires were shown to agree well with the standardized temperature curves, but they were significantly lower for diesel pool fires. Two exponential correlations on vertical temperature distribution were provided, respectively, for gasoline and diesel fires. These findings are expected to be useful for the design of the thermal boundary on the lining in tunnel fires.

An experimental and non-dimensional study on the vertical temperature distribution of a sealed ship engine room fire

2018 ◽  
Vol 165 ◽  
pp. 22-33 ◽  
Author(s):  
Jinhui Wang ◽  
Yu Jiao ◽  
Long Shi ◽  
Qimiao Xie ◽  
Guoqiang Li ◽  
...  
Keyword(s):  
Temperature Distribution ◽  
Vertical Temperature ◽  
Engine Room ◽  
Vertical Temperature Distribution

scholarly journals VI. The vertical temperature distribution the atmosphere over England, and some remarks on the general and local circulation

1912 ◽  
Vol 211 (471-483) ◽  
pp. 253-278 ◽  
Keyword(s):  
Temperature Distribution ◽  
British Isles ◽  
Vertical Temperature ◽  
Local Circulation ◽  
The Past ◽  
Rubber Balloon ◽  
Vertical Temperature Distribution

During the past four years a considerable number of small free balloons carrying selfrecording instruments have been sent up in the British Isles, and sufficient observations have now accumulated to give some idea of the conditions which prevail over England, to a height of about 10 miles, in summer and winter, in cyclonic and anticyclonic weather. The method of obtaining observations is fully described in a publication of the Meteorological Office, M.O. 202. It will suffice here to state that a small selfrecording instrument, weighing 1 oz. (35 gr.), is attached by about 30 ft. (9 metres) of strong thread to a small rubber balloon. The balloon is 1 ft. diameter when unstretched. It is filled with hydrogen until it is expanded to about 1 m. diameter, securely tied up, and then let go. The balloons generally rise until they burst, and carry the instrument on the average to a height of 10 miles (16 km). A label offering a reward of 5 s . is attached to the instrument, and the reward is claimed and the instrument returned in two cases out of three.

Multi-Cell Concept for Simulating Fires in Big Enclosures Using a Zone Model

1996 ◽  
Vol 14 (3) ◽  
pp. 186-198 ◽  
Author(s):  
W.K. Chow
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Temperature Distribution ◽  
Physical Properties ◽  
Flow Pattern ◽  
Layer Thickness ◽  
Zone Model ◽  
Smoke Layer

The multi-cell concept is applied to simulate fire in a big com partment with the zone model CFAST. The predicted physical properties of the smoke layer are used to justify the results, including the smoke layer tempera ture, smoke layer thickness and flows between each cell. Microscopic pictures of the flow pattern and smoke temperature distribution similar to the results pre dicted by the Computational Fluid Dynamics technique can be obtained. This idea is recommended to study fires in big enclosures.

Sign in / Sign up

Export Citation Format

Share Document