Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
A Methodology to assess Species Yields of Compartment Fires by means of an extended Global Equivalence Ratio Concept
About 70 % of fire deaths occur by inhalation of smoke, whose toxicity is for the most part due to CO. The approach of correlating CO generation in compartment fires with ventilation conditions has become known as the global equivalence ratio concept (GER-concept). The review and partial re-examination of the principal research work on CO yields from compartment fires demonstrate the feasibility of this concept. The correlations of CO yields with the GER given by Gottuk and Lattimer are basically confirmed by additional results from large-scale experiments in the ISO 9705 room. In addition to ventilation effects, which are of prime importance, vitiation effects were also studied. These become relevant when fuel is directly released into a vitiated upper layer. The particular case of pyrolysis of, for example, cellulosic fuels in vitiated upper layers leads to increased CO yields under well-ventilated conditions. The GER-concept was extended to cover external combustion, both by flame extensions and in under-ventilated conditions. To assess the second phenomenon, an ignition criterion proposed by Beyler has been extended by taking into account the combustion efficiencies both inside the compartment and overall. Numerical fire simulation with the Fire Dynamics Simulator (FDS4) is of limited suitability for providing functional simulation results to be used for the GER-concept. FDS4 output data was post-processed to assess the ignitability of the exhaust gases by Beyler’s ignition criterion. Beside of CO, species yields of other main asphyxiant and irritant species were scrutinised to be assessed by the GER-concept. An extended methodology to derive the carbon monoxide source term of compartment fires is presented, which considers the GER, the occurrence of external combustion, upper layer temperature effects, and fuel pyrolysis in the upper layer.
A Methodology to assess Species Yields of Compartment Fires by means of an extended Global Equivalence Ratio Concept
About 70 % of fire deaths occur by inhalation of smoke, whose toxicity is for the most part due to CO. The approach of correlating CO generation in compartment fires with ventilation conditions has become known as the global equivalence ratio concept (GER-concept). The review and partial re-examination of the principal research work on CO yields from compartment fires demonstrate the feasibility of this concept. The correlations of CO yields with the GER given by Gottuk and Lattimer are basically confirmed by additional results from large-scale experiments in the ISO 9705 room. In addition to ventilation effects, which are of prime importance, vitiation effects were also studied. These become relevant when fuel is directly released into a vitiated upper layer. The particular case of pyrolysis of, for example, cellulosic fuels in vitiated upper layers leads to increased CO yields under well-ventilated conditions. The GER-concept was extended to cover external combustion, both by flame extensions and in under-ventilated conditions. To assess the second phenomenon, an ignition criterion proposed by Beyler has been extended by taking into account the combustion efficiencies both inside the compartment and overall. Numerical fire simulation with the Fire Dynamics Simulator (FDS4) is of limited suitability for providing functional simulation results to be used for the GER-concept. FDS4 output data was post-processed to assess the ignitability of the exhaust gases by Beyler’s ignition criterion. Beside of CO, species yields of other main asphyxiant and irritant species were scrutinised to be assessed by the GER-concept. An extended methodology to derive the carbon monoxide source term of compartment fires is presented, which considers the GER, the occurrence of external combustion, upper layer temperature effects, and fuel pyrolysis in the upper layer.
A Methodology to assess Species Yields of Compartment Fires by means of an extended Global Equivalence Ratio Concept
Eine Methode zur Abschätzung der Schadstoffausbeuten von Raumbränden unter Erweiterung des Konzepts des globalen Äquivalenzverhältnisses
Forell, Burkhard (Autor:in) / Universitätsbibliothek Braunschweig (Gastgebende Institution) / Hosser, Dietmar (Akademische:r Betreuer:in)
2006
Institut für Baustoffe, Massivbau und Brandschutz, IBMB, der Technischen Universität Braunschweig - Materialprüfanstalt für das Bauwesen - MPA Braunschweig, vol. 198
Sonstige
Elektronische Ressource
Englisch
DDC:
624
| UB Braunschweig | 2007
| TIBKAT | 2007
Describing species yields of compartment fires by means of an extended global equivalence ratio
| British Library Conference Proceedings | 2005