Experimental Study of the Interaction Between Water Sprays and Smoke Layer

Experimental Study of the Interaction Between Water Sprays and Smoke Layer This paper concerns the interaction between water sprays and a smoke layer in a corridor, without any interaction with fire activity. Three water sprays are tested, a high-pressure water mist system and two sprinkler systems under different operating pressures. Our study aims to compare the impact of these three sprays on the smoke layer, based on the analysis of temperature and transmittance profiles. Characterization of the smoke layer before spray activation, based on either temperature or transmittance was found to be similar, providing a smoke free layer at around middle height in the corridor. During spray operation, discrepancies were observed in some cases depending on whether the smoke layer was studied based on the temperature or the transmittance profiles. Spray operation may provide gas cooling, resulting in homogeneous temperature profiles, while vertical variations of droplet size and soot or droplet concentration can still induce a variation in transmittance. The impact of water spray on the smoke layer varies with the spray system. For the water mist system and the highest-pressure sprinkler system, the spray operation induces a complete de-stratification with well-mixed steady-state conditions along the corridor as well as strong smoke cooling and visibility alteration. With the lowest-pressure sprinkler system, only a localized alteration of this stratification is observed under the spray, while the environment remains thermally and optically stratified downstream in the corridor despite spray operation. Relationships described in the literature were used to confirm and explain these observations. Ratios were evaluated to compare the drag effect due to the spray and the buoyancy effect related to the fire. All tests provided ratios of drag number over buoyancy number much greater than one. This confirms the ability of these relationships to predict the occurrence of de-stratification. Qualitatively, the highest ratios were found for the high pressure system and for the water mist system, which actually led to the most important de-stratification effects. In contrast, the weaker ratio found for the lower pressure system was still above one, i.e., coherent with a de-stratification which did not affect the whole corridor however. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Fire Technology Springer Journals

Experimental Study of the Interaction Between Water Sprays and Smoke Layer

Loading next page...
 
/lp/springer_journal/experimental-study-of-the-interaction-between-water-sprays-and-smoke-9bMOzXurDu
Publisher
Springer Journals
Copyright
Copyright © 2018 by Springer Science+Business Media, LLC, part of Springer Nature
Subject
Engineering; Civil Engineering; Classical Mechanics; Characterization and Evaluation of Materials; Physics, general
ISSN
0015-2684
eISSN
1572-8099
D.O.I.
10.1007/s10694-017-0693-8
Publisher site
See Article on Publisher Site

Abstract

This paper concerns the interaction between water sprays and a smoke layer in a corridor, without any interaction with fire activity. Three water sprays are tested, a high-pressure water mist system and two sprinkler systems under different operating pressures. Our study aims to compare the impact of these three sprays on the smoke layer, based on the analysis of temperature and transmittance profiles. Characterization of the smoke layer before spray activation, based on either temperature or transmittance was found to be similar, providing a smoke free layer at around middle height in the corridor. During spray operation, discrepancies were observed in some cases depending on whether the smoke layer was studied based on the temperature or the transmittance profiles. Spray operation may provide gas cooling, resulting in homogeneous temperature profiles, while vertical variations of droplet size and soot or droplet concentration can still induce a variation in transmittance. The impact of water spray on the smoke layer varies with the spray system. For the water mist system and the highest-pressure sprinkler system, the spray operation induces a complete de-stratification with well-mixed steady-state conditions along the corridor as well as strong smoke cooling and visibility alteration. With the lowest-pressure sprinkler system, only a localized alteration of this stratification is observed under the spray, while the environment remains thermally and optically stratified downstream in the corridor despite spray operation. Relationships described in the literature were used to confirm and explain these observations. Ratios were evaluated to compare the drag effect due to the spray and the buoyancy effect related to the fire. All tests provided ratios of drag number over buoyancy number much greater than one. This confirms the ability of these relationships to predict the occurrence of de-stratification. Qualitatively, the highest ratios were found for the high pressure system and for the water mist system, which actually led to the most important de-stratification effects. In contrast, the weaker ratio found for the lower pressure system was still above one, i.e., coherent with a de-stratification which did not affect the whole corridor however.

Journal

Fire TechnologySpringer Journals

Published: Jan 5, 2018

References

You’re reading a free preview. Subscribe to read the entire article.


DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Search

Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly

Organize

Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.

Access

Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

DeepDyve

Freelancer

DeepDyve

Pro

Price

FREE

$49/month
$360/year

Save searches from
Google Scholar,
PubMed

Create lists to
organize your research

Export lists, citations

Read DeepDyve articles

Abstract access only

Unlimited access to over
18 million full-text articles

Print

20 pages / month

PDF Discount

20% off