Validation of COCOSYS pyrolysis models on OECD PRISME fire experiments

Pelzer, Martin; Klein-Heßling, W.

doi:10.1016/j.firesaf.2013.01.016

Cited by 9 publications

(17 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…COCOSYS does not have implemented an empirical plume model. Gas entrainment into the fire plume and rising of hot gases are calculated as a volume flow through the respective junctions of frustum‐shaped control volumes in front of the cable trays. The opening angle affects the magnitude of this effect.…”

Section: Numerical Simulationsmentioning

confidence: 99%

Experimental and numerical analysis of the influence of cable tray arrangements on the resulting mass loss rate and fire spreading

et al. 2019

Self Cite

View full text Add to dashboard Cite

Summary In the context of industrial buildings and power plants, electrical installations and cable trays represent a main fuel load and a potential initial fire source due to possible short circuits or comparable malfunction. Furthermore, a fire can spread from one tray to additional trays mounted above and/or horizontally on one tray. Because of the high significance of cable fires, several research projects have been carried out, investigating the fire behaviour of cables from small‐scale tests, eg, the cone calorimeter, up to large‐scale tests, analysing complete cable tray constructions. The goal of the work presented in this paper is the extension of the knowledge regarding the influence of geometrical parameters like the packing density and tray distance on the burning behaviour and fire spread of cable tray installations. The results are considered, together with test results from the literature, to quantify the main physical parameters describing the burning behaviour. In a next step, the general applicability of these parameters as input data for the parametrization of the source term of numerical simulations is shown. The test results show that the burning behaviour and the fire spreading highly depend on the cable arrangement of the cables on the cable tray, in combination with other boundary conditions. By applying the results as input for a fire simulation, the mass loss rate is considered appropriately.

show abstract

Section: Numerical Simulationsmentioning

confidence: 99%

Experimental and numerical analysis of the influence of cable tray arrangements on the resulting mass loss rate and fire spreading

et al. 2019

Self Cite

View full text Add to dashboard Cite

show abstract

“…The LP containment code system (COCOSYS) developed by GRS primarily for comprehensive simulations of design basis and severe accidents in light water reactor (LWR) containments incorporates an oil fire model and a so‐called “simple cable fire” model as outlined in more detail in Pelzer and Klein‐Heßling . For fire simulations, the determination of the pyrolysis rate and the combustion rate is essential.…”

Section: Introductionmentioning

confidence: 99%

“…For fire simulations, the determination of the pyrolysis rate and the combustion rate is essential. Experiments show that the pyrolysis and combustion rate are affected by several factors such as the chemical composition of the oil/cable material, the geometrical arrangement of the cables, and the ventilation conditions …”

Section: Introductionmentioning

confidence: 99%

Validation of the lumped parameter code COCOSYS against large‐scale OECD PRISME 2 fire experiments

Klein-Heßling

2019

Fire and Materials

View full text Add to dashboard Cite

Summary Fire safety analysis is a major issue for nuclear power plants (NPPs) in the context of deterministic safety assessments as well as of probabilistic safety analyses. Oil reservoirs and cables represent major fire loads. Therefore, simulations of oil and cable fires are of interest for quantifying the risk of such internal hazards in NPPs. To investigate the applicability of lumped parameter (LP) modelling, validations against fire experiments are required. In this way, results obtained with the LP code COCOSYS for simulations of oil and cable fire experiments conducted in the OECD PRISME 2 Project are presented. The PRISME 2 VSP (vertical smoke propagation) tests involving oil fires in a confined and mechanically ventilated facility were used to assess the ability of the LP code to simulate smoke propagation through a horizontal opening from the fire compartment to a compartment on top of it. As it was already identified in the “International Collaborative Fire Modelling Project (ICFMP),” this type of opening might cause problems in fire simulations, particularly for zone or LP fire models. In these simulations, attention has been paid to the coupling between the fire and the surrounding environment due to the decrease of oxygen concentration. Furthermore, different cable materials have been tested in the PRISME 2 CORE (completing and repeating) test campaign. By simulating the CFS‐3 (cable fire spreading) test with confined underventilated conditions, the applicability of the COCOSYS cable fire model with input parameters deduced from open atmosphere fire tests (CORE‐2) was analysed. Results show that the applicability of a LP fire model to predict the pyrolysis rate is partly limited for both oil and cable fires, in confined environment. However, simulations with prescribed pyrolysis rates show encouraging results in good agreement with the experimental data and underline the capability of the LP code COCOSYS to simulate the interaction between the thermal hydraulics inside compartments and the fire source.

show abstract

“…Several aspects of the fire dynamics (e.g., mechanisms inducing pressure peaks at ignition and extinction) for different scenarios of interest have been extensively studied both experimentally and numerically (e.g., (Prétrel et al, 2005), , (Prétrel et al, 2012), (Lapuerta et al, 2012), (Bonte et al, 2013), (Wahlqvist and van Hees, 2013), (Pelzer and Klein-Hessling, 2013)). However, pressure and burning rate instabilities have been only experimentally reported and analysed.…”

Section: Introductionmentioning

confidence: 99%

Blind Simulation of Periodic Pressure and Burning Rate Instabilities in the Event of a Pool Fire in a Confined and Mechanically Ventilated Compartment

Beji

Merci

2016

Combustion Science and Technology

View full text Add to dashboard Cite

Fire dynamics in a well-confined and mechanically ventilated enclosure (a configuration of interest to the nuclear industry) strongly depends on the interaction between the fuel burning rates and the intake and exhaust volume flow rates (delivered by the fans). Several experiments show that, in the under-ventilated regime, an oscillatory behaviour may be established with frequencies in the order of few mHz. This paper reports one of the first comprehensive numerical analyses performed in order to study periodic pressure and burning 1 rate instabilities for the case of a full-scale heptane pool fire, for which experimental data has not been published yet. In the numerical analysis, carried out with the Fire Dynamics Simulator (FDS), periodic pressure and burning rate instabilities were predicted with a frequency of approximately 10 mHz. The analysis shows evidence of the correlation between the variation of ventilation flow rates (due to pressure instabilities) and the burning rate oscillations. The latter oscillations are directly linked to oscillations in the fuel burning area attributed to the ventilation-controlled conditions.

show abstract

Validation of COCOSYS pyrolysis models on OECD PRISME fire experiments

Cited by 9 publications

References 6 publications

Experimental and numerical analysis of the influence of cable tray arrangements on the resulting mass loss rate and fire spreading

Experimental and numerical analysis of the influence of cable tray arrangements on the resulting mass loss rate and fire spreading

Validation of the lumped parameter code COCOSYS against large‐scale OECD PRISME 2 fire experiments

Blind Simulation of Periodic Pressure and Burning Rate Instabilities in the Event of a Pool Fire in a Confined and Mechanically Ventilated Compartment

Contact Info

Product

Resources

About