Building a mathematical model for the heat build-up in the oil tank shell under the thermal effect of a combustible liquid pool fire within the tank dike. methodology. A thermal balance equation for an oil tank exposed to heat from the pool fire has been worked out. Both radiant and convective heat transfer processes between the pool fire and the environment have been taken into account. Estimates for the distribution of temperatures and airflow velocities in the plume above the fire have been used to account for the convection component of the heat flux from the pool fire. findings. Dynamics of the tank shell temperature change in time under the thermal effect of the pool fire within the dike has been obtained. The obtained expression is the solution of the differential equation worked out on the basis of the thermal balance analysis for the oil tank shell exposed to heat. originality. The convective component of the heat flux from the pool fire to the oil tank is taken into account and estimates of the distribution of temperatures and velocities in the plume are built. Practical value. The proposed model of the tank shell heat exposure to the pool fire within the dike could provide the basis for building a decision-making system for the fire response manager, outlining safe zones for positioning the equipment and personnel involved in fire-fighting, while developing fire pre-plans at the oil refining facilities and designing security systems for oil tanks.

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Purpose. To construct a model of extinguishing a spill fire spreading on a nonsmooth horizontal surface using water mist. Methodology. A force balance equation for the forces influencing the spilled liquid spread has been worked out. The equation takes into account the change in the mass of the spilled liquid due to its burnout and possible inflow in the case of a continuous spill. Filling of the surface irregularities in the spill area has also been taken into account. There has been worked out a thermal balance equation for the fuel surface under sprayed water mist, based on the assumption that the water droplets completely evapo rate before they reach the surface of the burning fuel. Findings. The dynamics has been obtained for the radius change of the fuel spill for the spread and burnout on a nonsmooth horizontal surface under the assumption of a circular shape of the spill. Relation has been determined between the time required to suppress a spill fire with water mist and the intensity of water feed. Originality. The scientific originality consists in taking into account the surface irregularities and fuel burnout during the spill spread, as well as determining the time required to suppress a spill fire with water mist, depending on the intensity of the water feed. Practical value. The proposed model for the fuel spill spread and fire extinguishing can serve as the basis for the design of a fire protection system for the processing equipment and, in particular, of an automatic water mist fire extinguishing system, at oil ex tracting and oil refining facilities.

A method for determining the dynamic parameters of the operator of a mobile fire engine based on a segway, which fully characterize its dynamic properties – delay time and inertia was developed. The development of the method includes four stages. At the first stage, the problem of obtaining analytical relationships for determining the dynamic parameters of the operator is solved. These relationships include the frequency characteristics of the operator at a fixed frequency and its static parameter. At the second stage, the choice of a fixed frequency is substantiated using a criterion that minimizes errors in determining the dynamic parameters. It is shown that the fixed frequency for the characteristic parameters of the operator does not exceed 0.5 Hz. The third stage includes substantiation of the procedure for determining the frequency characteristics of the operator and its static parameter. The frequency characteristics of the operator at a fixed frequency and its static parameter are determined numerically. This procedure is based on using the data obtained by measuring the values of the operator’s transfer function at fixed time intervals. To obtain data, an interactive analog engine is used, which can also perform the functions of a simulator. The time intervals are chosen according to the Kotelnikov-Nyquist-Shannon theorem. At the last stage, the procedure for determining the dynamic parameters of the operator of a segway-based mobile fire engine is described. It is shown that the error in determining the dynamic parameters of the operator of a mobile fire engine does not exceed 9.0 %, if the error in determining its frequency characteristics at a frequency of 2.5 s–1 does not exceed 2.0 %