Firerun: a computer program for the prediction of fire safety in the design of food services

This paper presents the research efforts underlying the development of a computer program for the computation of transient heat transfer between structural elements and a chimney for the prediction of fire. During the life time of a chimney in a fast food service, grease is accumulated on the walls while it is dragged by the smoke stream. If a fire is started inside the chimney, it may sustain for a while until all the grease has been burned out. Since the surface of the chimney reaches a much higher temperature during the fire than during its normal operation, there is a possibility that structural elements adjacent to the chimney may get damaged or ignite resulting in a massive fire of the building. The heat transfer from the chimney to the surrounding structure takes place primarily by radiation. Heat transfer inside the structure takes place by conduction and heat is dissipated from the structure to the ambient medium by natural convection. During the fire, the surface temperature of the chimney reaches around 1200°C. The code used for calculation was written in FORTRAN. The preprocessor and the post-processor were developed using Visual Basic. The program consists of four modules: Geometry Construction, Properties, Mathematical Calculations, and Results Plotting. The first module allows a user to generate the geometry in cartesian or cylindrical coordinates and lets the user observe the geometry being generated. The second one receives properties of the elements, and depending on these it does calculations to determine a suitable time step. The last module plots the results obtained from the FORTRAN program