TROSHKIN S. Research on the Fire Resistance of Enclosure Structures in Vertical Cable Tunnels of Nuclear Power Plants under Real Fire Conditions

Relevance. While studying the movement of the technological process on the issues of improving electrical systems, etc., the issue of fire safety remains open, which contains a serious threat. Extensive cable networks not only create a significant fire load, but also contribute to the spread of fire between buildings and structures, threatening the emergence of an emergency state of the technological process of energy enterprises. Solving the current problem of the influence of the geometric parameters of vertical cable tunnels of nuclear power plants, fire load, fire barriers and the influence of the existing fire extinguishing system on the fire resistance of building enclosing structures. Insufficient assessment creates fire safety risks in terms of evacuating people and conducting emergency rescue and operational work to eliminate the consequences of an emergency situation (emergency event), while overestimated safety factors can lead to unjustified costs. Taking into account the realities of today allows you to optimize construction costs, reducing them by 1.5-2%. All of the above shows the relevance of the task of revealing the patterns of dependence of the parameters of the temperature regimes of fires in vertical cable tunnels on their design characteristics, since this allows us to approximate the calculated temperature regimes of fires 3 for assessing the fire resistance of structures of vertical cable tunnels to real fire regimes. The object of the study is thermal processes that occur in vertical cable tunnels of nuclear power plants under fire conditions close to real ones. The subject of the study is the influence of the design parameters and fire load of cable tunnels on the fire resistance of their enclosing building structures. The purpose of the study is to reveal the patterns of dependence of the parameters of the temperature regimes of fires in vertical cable tunnels on their design features and fire load, as a scientific basis for improving the methods of calculating the fire resistance assessment of enclosing structures of cable tunnels under real fires that occur in them. To achieve the goal, the following tasks were formulated: 1. To analyze modern methods for assessing the fire resistance of enclosing structures of vertical cable tunnels of nuclear power plants, taking into account their design features and fire load when building mathematical models of the corresponding temperature regimes of fire; 2. To substantiate mathematical models of heat and mass transfer during a fire in vertical cable tunnels of nuclear power plants that take into account their design features and the existing fire load based on the application of numerical methods of computer gas hydrodynamics; 3. To develop a methodology and conduct experimental studies of the temperature regime in a vertical cable tunnel of a nuclear power plant, taking into account the real fire load. To study the adequacy of experimental and calculated data using statistical criteria for the reliability of statistical hypotheses in a comparative analysis of calculated and experimental data; 4. Conduct numerical experiments to study temperature regimes in vertical cable tunnels with different design characteristics, fire load, and existing fire extinguishing systems, based on which to identify patterns of dependence of the parameters of the temperature regime of fire on these characteristics. 5. Develop a calculation method for assessing the fire resistance of reinforced concrete enclosing structures of vertical cable tunnels of nuclear power plants using the identified patterns of dependence of the parameters of the temperature regime of fires on the design characteristics of cable tunnels and fire load.