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Introduction. Using air-filled foam to contain and liquidate the flaming combustion of liquefied natural gas spills is one of the most optimal methods of preventing the escalation of emergencies. However, the amount of data available today is insufficient to standardize the basic parameters of air-filled foam injection.The purpose of this research project is to justify the application of air-filled foam to contain and liquidate the flaming combustion of liquefied natural gas and identify the basic parameters of injection. The following objectives are to be attained towards this end:  assessment of the fire and explosion safety of liquefied natural gas and analysis of extinguishing means applicable to spills;  experimental determination of the insulating ability of foams, having different expansion factors, if applied to the surface of cryogenic fluid;  experimental determination of the fire-fighting efficiency of the foam used to liquidate the flaming combustion of liquefied natural gas;  experimental verification of expediency of the joint application of high expansion air-filled foam and extinguishing powders.Results and discussion. Having discussed the findings of the in-house experiments and analyzed the international and domestic tests conducted for this purpose, the authors assume that the application of the foam, whose expansion factor equals 300 to 500 units, can effectively contain and liquidate the flaming combustion of liquefied natural gas. The flaming combustion cannot be liquidated, if lower expansion factor foams are applied. The application rate of the high-expansion air-filled foam, exceeding 0.08 kg/(m2·s), is required to reduce the intensity of flaming combustion. Flaming combustion can be efficiently liquidated if the application rate of high-expansion air-filled foam is set at 0.17 ± 0.01 kg/(m2·s). Fire-extinguishing powders can only be efficiently applied to liquidate the flaming combustion of liquefied natural gas, if its surface is covered in foam.Conclusions. The authors have used their in-house experimental data, analyzed the literary sources and wellknown properties of the fire-extinguishing foam to justify the basic parameters of foam application aimed at the containment and liquidation of the flaming combustion of liquefied natural gas.

Introduction. The article considers the possibility of solving the problem of using automatic fire extinguishing systems to extinguish electrical equipment under voltage in rooms with no people. Examples of fires at energy facilities in recent years are considered, as well as statistics of fires at transformers in the Russian Federation in the period from 2016 to 2021. The analysis of normative legal acts of the Russian Federation and foreign analogs is carried out. As a result of the analysis, the problem of using automatic fire extinguishing installations at energy facilities has been identified. Targets and goals. The purpose of the study is to analyze the possibility of using automatic fire extinguishing systems for live electrical equipment at energy facilities. During the study, the following tasks were set: - analysis of regulatory legal acts of the Russian Federation and international standards in the field of extinguishing Class E fires; - analysis of fire statistics at transformer substations in the Russian Federation in the period from 2016 to 2021; - development of the concept of a test bench to determine the leakage current through the jet of fire extinguishing agent from automatic fire extinguishing installations when extinguishing electrical equipment under voltage. Methods. When conducting a study on the use of automatic fire extinguishing installations for live electrical equipment at energy facilities, the analysis method was used. Results and its discussion. As a result of the study, the problem of rationing and the use of automatic fire extinguishing installations for electrical equipment under voltage in rooms with no people was identified. The concept of a test bench for determining the leakage current through a jet of fire extinguishing agent from automatic fire extinguishing installations when extinguishing live electrical equipment is proposed. Conclusions. During the study, it was revealed that international standards and norms in the Russian Federation diverge in the field of application of automatic fire extinguishing installations for live electrical equipment at power facilities, therefore, further research and development of the proposed test stand is necessary to determine the leakage current through the jet of fire extinguishing agent from automatic fire extinguishing installations, which will allow to explore the possibility of using various types of automatic fire extinguishing installations, with different types of fire extinguishing agents to eliminate fires in electrical equipment under voltage. Keywords: automatic fire extinguishing installations, fire electrical equipment, fire protection, transformer, test bench.

PURPOSE. The article studies the issue of extinguishing live electrical equipment by means of automatic fire suppression systems (AFSS). The purpose of the work is to assess the possibility of personnel’s safe use of various types of automatic fire suppression systems when extinguishing live electrical equipment at power facilities. The authors analyze the statistics of transformer substation and cable duct fires in the Russian Federation within the period from 2018 to 2021 and regulations in the field of application of automatic fire suppression systems for extinguishing fires of live electrical equipment. A series of experiments was carried out to determine the leakage current when a fire extinguishing agent is supplied from AFSS to energized equipment. METHODS. To study the possibility of using AFSS in case of fires of live electrical equipment at power facilities, methods of analysis and experiment are used. FINDINGS. The first series of experiments was carried out on an automatic gas fire suppression system using halon 125 as a fire extinguishing agent. Extinction of B1 simulated fire sources filled with n-heptane was carried out. Over the whole experiment on the hand-operated starting device of the automatic system leakage current did not exceed the threshold non-perceptible value of 0.5 mA. The second series of experiments was carried out on a water spray automatic fire suppression system. The large spray angle of the nozzles prevented the entire amount of fire extinguishing agent from reaching the standard target; therefore, in order to obtain more accurate data, a new target sized 3 000×3,000 mm was manufactured. Spray nozzles with different k-factor values were investigated. The experiment made it possible to determine the values of leakage current on a pump unit body and spray nozzle. RESEARCH APPLICATION FIELD. The obtained experimental data indicate the possibility of safe use of water spray and gas automatic fire suppression systems to extinguish live electrical equipment. CONCLUSIONS. The results of the study can provide a substantiation for measures that exclude electric shock to facility personnel in case of using automatic fire suppression systems when extinguishing live electrical equipment.

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