SAVCHENKO O. Improvement of the method for assessing individual fire risk, taking into account the impact of fire protection systems

The dissertation is devoted to solving an urgent scientific and technical problem in the field of fire safety – identifying patterns of influence of fire protection systems on the calculated parameters of individual fire risk as a scientific basis for improving the method of assessing individual fire risk. An analysis of the current state of effectiveness of fire protection systems and an assessment of the nature of their impact on the magnitude of individual fire risk were carried out. It was established that the mechanisms of influence of these systems on the level of fire risk remain insufficiently studied. The existing structure of the fire protection system was analyzed with the definition of its main functions and tasks. It was established that the average efficiency of operation for all fire protection systems is approximately 50%. At the same time, the smoke protection system installed in the evacuation corridor increases the time of blocking evacuation routes by dangerous fire factors by approximately 34%. The selection and analysis of the most informative criteria suitable for assessing the impact of fire protection systems on the level of individual fire risk were carried out. It was substantiated that the determining indicators of reliability are the failure-free operation and the effectiveness of fire protection systems. A list of systems that have a significant impact on the level of individual fire risk was determined: fire alarm systems, fire notification and evacuation management systems, automatic fire extinguishing systems, as well as smoke protection systems. Assessment of the impact was carried out by comparing two alternative scenarios: fire development in the absence of the functioning of the corresponding fire protection system and under the condition of timely operation of the corresponding system. A structural scheme for studying the probability of effective operation of fire protection systems was proposed. The results of studying the impact of fire protection systems on the value of individual fire risk using field models are presented. Calculation models were built and calculations were performed for an office center, shopping center, and medical facility. One of the calculations was performed for an object where a fire occurred – Epicenter in Pervomaisk. The absolute deviations of calculation results from the actual consequences of the fire are 20 s for the time to reach visibility loss and 20 s for the time to reach the operating temperature of smoke protection dampers, which in relative terms does not exceed 10% and 20% respectively. Results of research using probability theory based on collected statistical data are also presented. The relative number of fires when the object is equipped with appropriate fire protection systems for different stages of fire liquidation was established. Dependencies of the effectiveness of functioning of the corresponding fire protection systems were built. The probability of effectiveness of fire protection systems functions, the probability of objects being equipped with fire protection systems, and the probability of serviceability of fire protection systems were determined. It was established that the values of the probability of effective operation of fire protection systems are: for fire alarm and notification systems – 0.61, for automatic fire extinguishing systems – 0.87, for smoke protection systems, internal and external fire water supply – 0.5. Experimental studies were conducted to verify the results obtained from theoretical research. The feasibility of applying probability theory methods and approaches based on field computer models was substantiated. Comparison of calculation results with experimental research data confirmed their adequacy and acceptable accuracy, as relative deviations did not exceed approximately 14% for fire alarm systems, about 20% for smoke protection systems, and about 7% for automatic fire extinguishing systems. An improved method for assessing individual fire risk taking into account the impact of fire protection systems was developed, which was implemented through the introduction of Amendment No. 1 to DSTU 8828:2019 "Fire Safety. Basic Provisions". An algorithm for substantiating the equipment of an object with appropriate fire protection systems based on fire risk management was developed, which allows, based on a risk-oriented approach, to assess the need to equip construction objects with appropriate fire protection systems. The research results found practical application in the activities of the Ministry of Development of Communities and Territories of Ukraine, the "Ukrainian Union of Fire and Technogenic Safety", in the work of LLC "Flagship of Safety Systems", and were also integrated into the educational process of the National University of Civil Protection of Ukraine.