Introduction. Vent stacks are used for the safe release of liquefied natural gas (LNG) vapors from safety valves. Unlike flare stacks, they are not designed for gas combustion; however, there is a risk of their ignition from external sources, such as lightning strikes or static electricity. Prompt extinguishing of such a fire helps prevent prolonged thermal impact on the structures.

Research Methodology. At the test site, a gas-powder fire extinguishing module was connected to the base of a vent stack mock-up. After igniting the LNG vapors at the head of vent stack and stabilizing the flame, the fire extinguishing module was manually activated. The extinguishing result was recorded visually.

Results. It was established that supplying a gas-powder fire extinguishing composition (GPFEC) into the pipe interior of the vent stack leads to the extinguishing of the fire at the head. Complete extinguishing was achieved with a GPFEC flow rate of at least 1.8 kg/s. Based on the obtained data, parameters for designing gas-powder fire extinguishing systems were determined. The consumption of the fire extinguishing agent must be at least 311 kg/m2, and the supply intensity at least 102 kg/(m2∙s), calculated based on the cross-sectional area of the vent stack.

Conclusions. The proposed method of supplying the GPFEC into the pipe interior is an effective way to extinguish a fire on a vent stack. The obtained experimental values of the extinguishing composition flow rate and supply intensity can be used to calculate the parameters of gas-powder fire extinguishing systems when protecting vent stack.

Introduction. The relevance of reconstructing the scenario of an emergency explosion is due to the direct relationship between the type of explosive phenomenon and the subsequent development of the emergency situation, as well as the final configuration of the destruction. Since the dynamic characteristics of explosive loads demonstrate significant variability, the overall morphology of the destruction will differ according to these parameters. The relevance of the problem is also dictated by the urgent need to improve the methods of predicting the loads resulting from emergency explosions. The observed imperfections in existing methods lead to obtaining only approximate values of the explosive loads that affect capital construction facilities.

Goals and objectives. The purpose of the paper is to identify the key characteristics of emergency explosions that allow for the reconstruction of emergency scenarios and contribute to the improvement of methods for predicting explosive loads, as well as the optimization of measures for preventing accidents.

To achieve this goal, the following objectives were set:

• analysis of emergency situations that occur in industrial and civil construction;
• conducting experimental studies in a small-scale test chamber and a large room.

Methods. Analysis of emergency situations that occur at construction sites. Measurement of overpressure in small-scale experimental chambers and a large room. Processing of experimental data using the MATLAB programme and subsequent analysis of the results.

Results and their discussion. It is shown that in deflagration explosions, which is typical for the vast majority of emergency explosions, the principle of quasi-static overpressure is observed under certain conditions, which imposes certain specific features on the destruction caused by dynamic explosive loads. For large rooms, the principle of quasi-static explosive pressure is violated, which leads to the occurrence of wave phenomena. It was shown that air shock waves accompanying emergency detonation and physical explosions have a lower destructive capacity, which is mainly focused on fragile window glass.

Conclusions. The identified characteristics of accidental explosions make it possible to reconstruct the scenarios of such explosions with the greatest accuracy. The materials presented in the paper can be used in the prediction of explosive loads resulting from various accidents, as well as in the development of measures for the prevention, localization, and elimination of their consequences.

Introduction. Fires in halls with a large number of people are characterized by the rapid spread of dangerous factors, which critically limits the time to save people. A particular threat is the use of combustible acoustic trim, which significantly accelerates the development of a fire.

Aims and objectives. The aim of the study is to quantify the effect of combustible acoustic panels on the dynamics of changes in the average volume temperature, range of visibility and concentration of carbon monoxide compared with non-combustible analogues (NA group) in a room with a volume of 6,000 m3. The objectives of the study are: the construction of calculated fire scenarios for a hall with a volume of 6,000 m3 with combustible and non-combustible acoustic finishes, numerical modelling of changes in the average volume temperature, visibility and concentration of carbon monoxide using a single-zone integral model, as well as determining the time to reach critical values of fire hazards.

Methods. The mathematical model of pyrolysis is formulated in a single-zone formulation based on the equations of energy and material balance, which relate the total heat output of a fire and the mass rate of burnout of finishing materials with the evolution of the average volume temperature, smoke and carbon monoxide concentration.

Results and discussion. Based on a system of differential equations of energy and material balance, a numerical experiment was conducted for a 600 kW hearth. It was found that in the presence of combustible elements, the critical values of temperature (70 °C), visibility (5 m), and carbon monoxide (0.116 %) are reached at 528, 665, and 681 seconds, respectively. In the scenario using NA group materials, the smoke and toxicity thresholds are not exceeded during the estimated interval of 1,200 seconds, and the critical temperature rise occurs with a significant delay (at the 862nd second).

Conclusion. The use of combustible materials leads to the blocking of escape routes in the range of 9 to 12 minutes, which is unacceptable for facilities with a mass presence of people. The necessity of strict limitation of the use of combustible acoustic panels is substantiated and the effectiveness of the use of single-zone forecasting for the early design stage is confirmed.

Introduction. Fire and rescue services operate amid uncertainty and technological challenges, increasing the need for engineering innovations. Their effect depends on implementation governance, regulatory approval, and integration into operational practice. Adaptive management models are required, relying on effectiveness metrics and feedback. The approach is illustrated with automatic fire containment systems (AFCS) for facilities where water suppression is unacceptable or ineffective.

Aim and objectives. The aim of this study is to justify an adaptive approach to managing the implementation of engineering and technical innovations in the fire and rescue sector based on mathematical modelling. The study addresses the tasks of formalizing the functioning of the fire and rescue service, constructing a Markov model of the facility’s states during a fire, assessing the probabilities of damage levels, comparing discrete and continuous models, and developing an adaptive model for the transfer of innovations.

Methods and research. Discrete- and continuous-time Markov chains, graph and matrix modelling, and numerical computation of steady-state probabilities were used. Life-cycle analysis and synthesis of regulatory, technical, and operational experience in AFCS deployment were applied.

Results and discussion. A Markov model of AFCS functioning, including operating modes and damage levels, was developed. Transition probabilities (discrete time) and Kolmogorov equations (continuous time) were obtained, and equality of limiting state probabilities was shown. Modelling quantified the influence of AFCS reliability and organizational factors. A closed-loop adaptive innovation transfer model was proposed. The research supported development of a GOST standard for AFCS.

Conclusions. Markov chains are suitable for assessing AFCS performance and damage probabilities; limiting probabilities are invariant to the time representation. Technology transfer depends on embedding innovations into regulations and operation. The proposed adaptive transfer model supports sectoral self-renewal within the sector overall.

Introduction. The problem of differentiating between primary and secondary fire sources is quite pressing when diagnosing secondary fire sources during forensic fire investigations. The complexity of the task lies in the need to simultaneously determine two independent variables — temperature and duration of high-temperature exposure. Solving this complex problem is a pressing research objective.

Goals and Objectives. The purpose of this paper is to develop a method for assessing the temperature and duration of high-temperature exposure to polymeric finishing materials. To achieve this, specimens of finishing building materials exposed to varying degrees of thermal stress were tested. Thermoanalytical characteristics that significantly characterize the thermal-oxidative degradation of the studied material were determined; empirical equations were derived for calculating the temperature and duration of preliminary high-temperature exposure of the material.

Methods. Simultaneous thermal analysis was used to test polymer material specimens, while correlation-­regression analysis and multiple linear regression were used to develop a method for estimating the temperature and duration of high-temperature exposure of the material.

Results. The regularities of thermo-oxidative degradation of the polymer material under study were investigated. It was established that the significant thermoanalytical characteristics (criteria) for assessing the temperature-
time exposure to the polymer material under study are the ash residue and the temperature of thermo-oxidative degradation. Empirical equations were obtained that make it possible to calculate the temperature and duration of high-temperature exposure to the laminate during a fire.

Conclusions. A method for assessing the temperature and duration of high-temperature exposure of building finishing materials was developed, enabling the diagnosis of secondary fire sources. Validation of the developed methodological approach and the method for assessing two independent variables demonstrated the reliability of the proposed approach and the validity of the obtained results.

Introduction. Modern warehouses are complex facilities characterized by a high concentration of material assets, while the risk of large-scale fires necessitates rapid fire localization. Conventional methods fail to provide the required response speed; therefore, automated “detection – targeting – suppression” systems employing unmanned aerial vehicles (UAV) are proposed.

Aim. To assess the feasibility of rapid-fire suppression in warehouse complexes using autonomous UAV and to propose its conceptual framework.

Purposes. To analyze existing fire suppression methods and substantiate the need for a rapid-response system; to develop a closed-loop concept incorporating detection, targeting, and suppression subsystems; to build a mathematical model for determining the required number of UAV; and to perform a comparative simulation of fire detection time using smoke detectors and video monitoring.

Materials and methods. We used systems analysis; detection times were estimated by simulating fire and smoke propagation in a typical warehouse with Fire Dynamics Simulator. The UAV-quantity model applied a geometric approach with corrections for three-dimensional space and shelving. Comparative assessment relied on modelling data.

Theoretical bases. The work is based on the laws of thermal radiation and light scattering, as well as the fundamental principles of dynamics and kinematics.

Results and discussions. A mathematical model was developed to determine the number of UAV, taking into account the warehouse area and response time; Simulation showed that a video surveillance system with smoke detection identifies the source of a fire in less than 10 s and outperforms traditional smoke detectors in terms of speed; the possibility of using multi-rotor UAV with a payload of around 20 kg for the targeted delivery of fire-­extinguishing agents was considered.

Conclusions. The results obtained confirm the effectiveness of using UAV to reduce the time between detection and the start of firefighting; the model developed enables the system’s configuration to be optimized; the proposed closed-loop system is capable of enhancing fire safety in warehouse complexes.