Ulf Göransson

A Model For Prediction Of Temperature In Steel Structure Protected By Intumescent Coating, Based On Tests In The Cone Calorimeter

Intumescent coating is an important fire protection method for steel structures. Traditionally its fire properties have been evaluated by performing furnace tests using a standardized test procedure and following a standardized time-temperature curve. This procedure is restrictive in performance based fire safety engineering design since it limits the fire condition to the standard one only. In this paper, a model is outlined that can take into account the different fire protection abilities of intumescent coating that will occur depending on what type of fire the coating is subjected to. The model is based on a experimental study, containing about 50 tests, performed in the Cone Calorimeter. Some test results are presented as well as an analysis model of the test results. (Less)

Validation of CFD Model for Simulation of Spontaneous Ignition in Bio-mass Fuel Storage

Both numerical simulations and experimental measurements of small scale spontaneous ignition with different biomass fuels have been performed. In the experiments, temperature history was monitored at five different locations inside the fuel bed. The measured temperature history was used for validation of comprehensive threedimensional computer simulations which were carried out using a parallel finite volume CFD code SMAFS (Smoke Movement and Flame Spread) developed by the first author. The computation was based on numerical solution of a set of governing equations including the continuity equation, extended Darcy momentum equations, energy conservation equations for both gas and solid phases, and mass conservation equations for different chemical species. With reliable material properties input data provided by separate measurements, it simulated the temporal state evolution inside the biomass fuel storage. In the simulation, consideration was given to a series of essential physical and chemical processes, including convection and diffusion in porous media, evaporation, condensation and heat generation which is mainly due to chemical oxidation. Numerical results were compared with experimental measurements, showing excellent agreement. (Less)

Using oxygen-quenched pressure-sensitive paint for oxygen concentration measurements in low-temperature combustion environments

The feasibility of using pressure-sensitive paint for oxygen concentration measurements in low-temperature combustion environments has been investigated and applied to slow combustion processes. In addition, the temperature limitation for this application was studied. A Nd:YAG laser system, a PMT and fiber-optics were used for developing a compact probe for oxygen measurements. The lifetime sensitivity to oxygen concentration and temperature of a commercially available pressure-sensitive paint has been investigated with regard to possible abilities and limitations. After calibrations with regard to temperature, measurements in slow combustion environments showed that the technique is capable of accurately measuring oxygen concentration in environments up to 180 °C. The measurements indicate usability also in the combustion area despite issues of thermal quenching and quenching from NO. The compact design of the system makes it a useful tool for oxygen measurements in situations where suction probes and other oxygen measurement techniques are too intrusive.