MODELLING OF THE START AND DEVELOPMENT OF FIRES IN CLOSED VOLUMES OF GREAT LENGTH

Abstract

The mathematical model of fire development in view of oxygen amount is represented. Heat-source is not given in the form of an empirical dependence of time, but is concerned with moving in space. We accept that fire begins in some distance from the entrance. Increasing of the fire size leads to reduction of oxygen to 10 – 11%. By a 10-minute period concentration of oxygen falls almost to zero and only at 20th minute increases to 14%. At the same t ime the temperature in contrast the oxygen concentration, on the contrary, sharply increases, wi th a maximum at the end of the fire, then there is a slow decrease in temperature by heat exchange with the walls of the channel.