Mätning av infallande strålning med plattermoelement från en propanflamma - uppställd fritt och mot väggar

For activities with increased safety, like nuclear power plants, it is important to investigate a proper safety distance from a fire with known characteristics. Depending on the ignition temperature and thermal properties such as the thermal conductivity k, density ρ and specific heat capacity C for the surrounding material, different safety distances will be derived. This can be made by investigating the temperature and incoming radiation to a surface. There are several different ways to determine the temperature and radiation like computer programs, hand calculations or performing a full-scale experiment. The aim of this thesis is to determine the adiabatic surface temperature (AST) and radiation at different distances from a fire with a given effect, resulting in a safety distance. This will be made by examine differences in results between full-scale experiments, an excel-application based on hand-calculations and the computer programme Fire Dynamics Simulator (FDS). The excel-application calculates the incident radiation and the AST. The hand-calculations that are used in the excel-application are based on different parameters and formulas, such as the combustion efficiency of the flame, how sooty the flame is and the view factor.Three different full-scale experiments are made at SP Fire Research in Borås which are based on an earlier written report which used FDS to determine a safety distance. These three experiments were: a flame freely placed in a room, flame against a wall and flame in a corner. Several 30 mm insulated plate thermometers were used during these experiments on different heights to get the AST. The propane burner had an effect of 500 kW and a safety distance was measured based on chosen criteria. These criteria’s were met when the temperature of the instrument reached 205 °C or was exposed to an incident radiation of 6 kW/m2. This temperature and incident radiation is based on research done by Electric Power Research institute (EPRI) [1]. The values are damage criteria’s identified for when ignition is identified on thermoplastic cables. For the full-scale experiments a significantly higher temperature was achieved when the burner was placed next to a wall or a corner compared to when the burner was placed freely. There was no bigger temperature difference if the burner was placed against a wall or a corner.The results from the excel-application corresponded well to the full-scale experiments and therefore similar safety distances were given. For the full-scale experiments the safety distance was reached at a distance of 0.85-1.35 m from the edge of the burner for the free flame and 1.85 m when the flame was placed against a wall or when the flame was placed in the corner. For the excel-application the safety distances were 1.2 m respectively 2.0 m for the free flame and the flame against the wall. No calculations were made for flame in corner due to the fact that there was no remarkable temperature difference compared to the flame against the wall. These results can be compared to FDS where the safety distances were the same for all cases, 1.5 m.Validerat; 20151006 (global_studentproject_submitter