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Modelling of hydrogen cyanide formation in room fires

Tuovinen, H; Blomqvist, P and Saric, Fikret LU (2004) In Fire Safety Journal 39(8). p.737-755
Abstract
A chemical kinetics model for calculation of the formation of hydrogen cyanide (HCN) has been made. The combustion of a mixture of methylamine and ethylene has been modelled using the stationary laminar flamelet concept. The flamelet calculations are based on several thousand elementary reaction steps including the chemical kinetics of HCN in combustion. The flamelets for both cold (293 K) and hot (1000 K) combustion product recycling have been calculated. The effect of strain is also included in the flamelet calculations. Scalar dissipation rates from 0.01 s(-1) to extinction values have been varied. Also the effect of radiation is included in the flamelet state relationships. Separate flamelet sets for various levels of radiation, from... (More)
A chemical kinetics model for calculation of the formation of hydrogen cyanide (HCN) has been made. The combustion of a mixture of methylamine and ethylene has been modelled using the stationary laminar flamelet concept. The flamelet calculations are based on several thousand elementary reaction steps including the chemical kinetics of HCN in combustion. The flamelets for both cold (293 K) and hot (1000 K) combustion product recycling have been calculated. The effect of strain is also included in the flamelet calculations. Scalar dissipation rates from 0.01 s(-1) to extinction values have been varied. Also the effect of radiation is included in the flamelet state relationships. Separate flamelet sets for various levels of radiation, from adiabatic up to 30% radiation losses, incremented by 1%, have been made. In the flow field calculation, the flamelet options may be used either as adiabatic, constant radiation or an interpolation between flamelet sets of different radiation. The chemical kinetics model, incorporated into a Reynolds-Averaging Navier-Stoke (RANS) type CFD code, has been used to simulate two laboratory fire tests of the combustion of nylon. Changing the size of the opening in the test room varied the ventilation between the two tests. Flamelet sets for a mixture of methylamine and ethylene with nitrogen content close to that of nylon were used in these simulations. The simulations were made with and without recycling the combustion products back to the fire. The calculations show that recycling of the combustion products to the fire increases the formation of HCN and CO. Similarly, a lowered ventilation rate increases the formation of these species. The calculated temperatures and main species concentrations, including HCN, agree reasonably well with the trends in the laboratory measurements. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
hydrogen cyanide, flamelet models, CFD models, vitiation, under-ventilated fires
in
Fire Safety Journal
volume
39
issue
8
pages
737 - 755
publisher
Elsevier
external identifiers
  • wos:000225369800006
  • scopus:6344258513
ISSN
0379-7112
DOI
10.1016/j.firesaf.2004.07.003
language
English
LU publication?
yes
id
99ee7211-48b1-4e11-82d8-61017ab00063 (old id 259664)
date added to LUP
2007-10-26 09:21:48
date last changed
2017-12-10 04:30:28
@article{99ee7211-48b1-4e11-82d8-61017ab00063,
  abstract     = {A chemical kinetics model for calculation of the formation of hydrogen cyanide (HCN) has been made. The combustion of a mixture of methylamine and ethylene has been modelled using the stationary laminar flamelet concept. The flamelet calculations are based on several thousand elementary reaction steps including the chemical kinetics of HCN in combustion. The flamelets for both cold (293 K) and hot (1000 K) combustion product recycling have been calculated. The effect of strain is also included in the flamelet calculations. Scalar dissipation rates from 0.01 s(-1) to extinction values have been varied. Also the effect of radiation is included in the flamelet state relationships. Separate flamelet sets for various levels of radiation, from adiabatic up to 30% radiation losses, incremented by 1%, have been made. In the flow field calculation, the flamelet options may be used either as adiabatic, constant radiation or an interpolation between flamelet sets of different radiation. The chemical kinetics model, incorporated into a Reynolds-Averaging Navier-Stoke (RANS) type CFD code, has been used to simulate two laboratory fire tests of the combustion of nylon. Changing the size of the opening in the test room varied the ventilation between the two tests. Flamelet sets for a mixture of methylamine and ethylene with nitrogen content close to that of nylon were used in these simulations. The simulations were made with and without recycling the combustion products back to the fire. The calculations show that recycling of the combustion products to the fire increases the formation of HCN and CO. Similarly, a lowered ventilation rate increases the formation of these species. The calculated temperatures and main species concentrations, including HCN, agree reasonably well with the trends in the laboratory measurements.},
  author       = {Tuovinen, H and Blomqvist, P and Saric, Fikret},
  issn         = {0379-7112},
  keyword      = {hydrogen cyanide,flamelet models,CFD models,vitiation,under-ventilated fires},
  language     = {eng},
  number       = {8},
  pages        = {737--755},
  publisher    = {Elsevier},
  series       = {Fire Safety Journal},
  title        = {Modelling of hydrogen cyanide formation in room fires},
  url          = {http://dx.doi.org/10.1016/j.firesaf.2004.07.003},
  volume       = {39},
  year         = {2004},
}