Building structures of thermal power plants: analysis of fire resistance limits

Introduction. The author analyzes real-life fire resistance limits of metal structures for one building of a thermal power plant. Experimental and computational methods were applied to identify the fire resistance limits of building structures. The temperature setting of the research, conducted to solve the problem, was the same as that of a real fire. Research goal and objectives. The purpose of the analysis is to identify the fire resistance limits of structures comprising the building of a thermal power plant using the method of heat-mass exchange analysis that takes account of conditions of a real fire. The following objectives are to be attained in compliance with the pre-set goal: to analyze the principal provisions of technical norms and regulations in terms of the fire safety of building structures of thermal power plants; to justify the principal provisions for the method of heat-mass exchange analysis, taking into account real-life fire conditions; to justify the need to improve the real-life fire resistance limits by fire-proofing agents with account taken of the most dangerous scenario of the real fire development. Methods of research. The heat-transfer equation is analyzed to identify the distribution of temperatures inside a building structure for a one-dimensional case. The field-based method of analysis is applied to solve this problem. This method is generally applied to premises having complex geometric configuration, if one geometric dimension exceeds the others. Results and their discussion. The authors have analyzed the most dangerous fire scenario characterized by the most dangerous impact on metal structures, such as the furnace oil fire spill in a boiler room. The authors also address the most dangerous fire propagation scenario in terms of the heating of bearing metal structures: the combustion of furnace oil spills in a boiler room. The computations have proven that in case of the selected fire development scenario maximal temperatures of bearing metal structures are much lower than the critical temperature of 500 °С fifteen minutes after the onset of fire. Conclusions. Having analyzed the fire resistance computations of thermal power plant structures, including their metal constructions, the have found that in case of emergency, resistance to the most dangerous manifestations of fire exceeds the required R15 value. No fireproofing of bearing metal structures in the boiler room is needed.