Предотвращение каскадного развития пожара на тепловых электростанциях Вьетнама на основе применения резервуаров с защитной стенкой и волноотражающим козырьком

Abstract

PURPOSE. The article, based on the results of an statistics analysis of vertical steel tanks (VST) destruction with flammable liquids, as well as forecasting the situation on the territory of a thermal power plant (TPP) during destruction of a typical VST-20 000 m3 with fuel oil, substantiates the need to use tanks with protective wall (TPW) and a wave-reflecting visor in tank farms at thermal power plants in Vietnam, as one of the promising methods aimed at preventing the possible cascading fire development at the facility or the occurrence of an emergency situation (ES). The main provisions of the method developed on the basis of performed experimental studies have been presented, which establishes the procedure for calculating the geometric parameters of a protective wall with a horizontal or inclined wave-reflecting visor, designed to completely contain the breakthrough wave during the quasi-instantaneous destruction of the main (internal) VST. METHODS. In the process of research methods of similarity theory and hydraulic laboratory modeling, physical experiment, observation, comparison, finding an empirical relationship based on mathematical processing of experimental data, description and generalization have been used. FINDINGS. The features of the location of thermal power plants in Vietnam have been revealed, consisting in their direct location in populated areas or near water bodies. It has been established that destruction of even one large-sized VST with flammable liquid in the tank farm of a thermal power plant can lead to a cascade development of an accident or emergency occurrence. It has been proven that installing a wave-reflecting visor on the protective wall is an effective way to reduce it to or below the maximum liquid level in the main VST, depending on the distance between the walls and the length of the visor extension. RESEARCH APPLICATION FIELD. The developed method, containing calculation schemes and empirical dependencies, can be the basis for the development of a regulatory document to ensure fire safety of TPW, including when they are located on the territory of tank farms of thermal power plants. CONCLUSIONS. The proposed design of the PWT, improved by installing a wave-reflecting visor, will make it possible to design and operate these types of tanks, ensuring the required level of fire, industrial and environmental safety at the protection site, subject to, among other things, the requirements for the stability of the wall and the visor to the effects of liquid flow and the main VST structures that collapse during an accident.