Vertical Steel Tanks Research Articles

Building a model of heating an oil tank under the thermal influence of a spill fire

The object of this study is the process of liquid combustion in a spill, and the subject of research is the distribution of temperature along the wall and roof of a vertical steel tank that is heated under the thermal influence of a spill fire. The heat balance equation for the wall and roof of the tank with oil product was constructed. The assumption of a small thickness of the wall and roof of the tank relative to its linear dimensions makes it possible to move to two-dimensional differential equations of the parabolic type. The equations take into account the radiative heat exchange with the flame, the environment, the internal space of the tank, as well as the convective heat exchange with the surrounding air, the vapor-air mixture, and the liquid inside the tank. Using the methods of similarity theory, estimates of the coefficients of convection heat exchange of the outer surface of the tank with the surrounding air and the inner surface with the vapor-air mixture and liquid in the tank in the conditions of free convection were constructed. The application of the finite difference method for solving the heat balance equations has made it possible to derive the temperature distribution on the surface of the tank at an arbitrary moment in time. It is shown that the value of the coefficient of convection heat exchange of the liquid exceeds the corresponding value for the air-vapor mixture by (1÷2) orders of magnitude. As a result, the part of the wall located below the oil product level is heated to a temperature of (80÷230) °C depending on the viscosity of the liquid. This occurs despite the fact that the value of the mutual radiation coefficient reaches its maximum value at the lower part of the wall. From a practical point of view, this means that the part of the wall above the level of the oil product in the tank can reach dangerous temperature values, and it should be cooled first. The constructed model of tank heating also enables determining the limit time for the start of cooling of the tank.

Devising technology for extinguishing oil tanks using compressed foam by sub-layer technique

Tank facilities storing various combustible substances are a potential source of danger for the environment and human life. Fires in tanks can occur for various reasons: technical malfunctions, human factors, military operations, natural phenomena. One of the effective methods for extinguishing such fires is "sublayer" extinguishing with the help of foam of low multiplicity. The possibility of "sub-layer" extinguishing with the help of compression foam, which has unique properties, has been considered. The object of this study is the processes of stopping combustion during fire extinguishing in steel tanks for the storage of petroleum products with the use of foaming agents of increased stability, which ensure the generation of compression foam in a "sub-layer" way. A mathematical model of the movement of a submerged non-free jet of foam in the medium of motor fuel is given, which adequately describes the real physical processes that occur during "sublayer" quenching of vertical steel tanks. According to the research, it was established that the use of foam with a multiplicity of 10 (K10) is 1.56 times more effective in serving time than the use of foam with a multiplicity of 5 (K5). From an economic point of view, K10 foam also has greater advantages as the costs of the foaming agent during its generation are 3.1 times lower than when using K5 foam. The simulations demonstrated that the foaming agent consumption of the K10 foam is lower than the foaming agent consumption of the K5 foam and results in a different amount of foam coming to the surface. The simulations also showed that the volume of K5 foam increases proportionally with the feeding time, while the volume of K10 foam increases disproportionally and starts to decrease after half the time. The results from the implementation of the mathematical model were fully consistent with the results from experimental studies on extinguishing a model fire of class B

Скінченно-елементна модель вертикального резервуара на жорсткій основі

This study addresses the problem of finite element modeling of a 20,000 m3 vertical steel tank subjected to static loads. The structure includes a cylindrical wall of total height 17,880 mm and diameter 39,900 mm. The shell thicknesses of the cylindrical wall are determined according to strength and buckling design standards. The geometric model is axisymmetric. The analysis involves the calculation of the stress and strain fields of the cylindrical wall and the contact zone between the flat bottom and the rigid foundation under various combinations of external loads, namely, excessive and hydrostatic pressures. The ANSYS Mechanical software is used for finite element analysis. Three-dimensional SOLID186 and SHELL281 elements are used for axisymmetric modeling of the shell structure in a three-dimensional formulation. To simulate the contact zone, CONTA174 and TARGE170 finite elements are used to model the moving contact surface of the bottom and the fixed surface of the rigid foundation, respectively. The model is verified by comparing the radial displacements calculated numerically and analytically. The discrepancy does not exceed 4%, thus evidencing the adequacy of the finite element model. The contact zone is analyzed for non-standard service conditions, such an excessive internal pressure in the tank (2.5 and 3 kPa compared to 2 kPa under normal conditions). The unilaterally constrained "bottom–foundation" contact zone model allows the bottom to detach from the foundation, thus leading to contact opening. A full detachment occurs under a certain combination of the excessive and the hydrostatic pressure. For certain liquid levels in the tank, the gap decreases, which may be due to a reduced effect of the excessive pressure. This is accompanied by the development of internal detachment caused by the increasing moment from the hydrostatic pressure. The internal detachment increases the bending moment at the wall–bottom junction, which, under certain conditions, may cause plastic deformations followed by the development of an emergency state.

Создание специализированного программного обеспечения для оперативного подсчета объемов потерь углеводородов в резервуарах

<p>Ensuring modern storage of hydrocarbons is not a trivial task. The existing requirements imposed by environmental and fire protection legislation, as well as the economics of production, oblige the owners of tank farms to take measures for calculation and reduction of petroleum products losses. For solvation of this problem, a group of calculation methods has been formed. They are allow to determine the volume of hydrocarbon losses during large and small breaths in tank farms. At the same time, carrying out calculations and selecting the appropriate equipment to reduce losses is quite difficult for the engineering and technical personnel of oil storages. In this regard, based on the calculation methods of V.I. Chernikin, F.F. Abuzova and N.N. Konstantinov the software for calculating hydrocarbon losses in reservoirs from large and small respirations was developed. Software has the ability to store data for a month daily and with a system of issuing recommendations regarding the use of means to reduce hydrocarbon losses. To write the program code, C# was used in Visual Studio 2022. The demo version of the program allows to calculate the volume of losses of petroleum products in vertical steel tanks of various sizes and under changing environmental conditions, and also, based on the embedded database, recommend the necessary means of losses reduction for installation on the tank</p>

Влияние скорости воздушного потока на тепловое излучение от углеводородного пожара в резервуаре для хранения нефти

Purpose. The article assesses the effect of air flow velocity on the intensity of thermal radiation from a fire in a vertical steel tank with a floating roof of 65 000 m3 capacity (VSTWFR-65000) with crude oil. The indicators of hazardous fire factors - open flame, smoke and temperature at different wind speeds – have been studied. Methods. The method of numerical modeling in the Fire Dynamics Simulator software package, as well as the method of processing the obtained research results have been used in the study. Findings. The dependence of the flame inclination angle at different air flow speeds has been obtained. The simulation results have been shown: smoke distribution at different wind speeds, as well as temperature change at a distance from the fire source depending on the air flow velocity. Research application field. The results of the study can be used in the development of design documentation for measures to ensure fire safety of a tank farm with floating roof tanks, as well as in adjusting fire extinguishing plans. Conclusions. Based on the simulation results it has been found that with an increase in the air flow velocity the intensity of thermal radiation initially increases and then decreases. It has been found that at an air flow velocity of 9 m/s the maximum thermal radiation reaches 23.43 kW/m2 at the nearest point of the adjacent tank in the projection from the central axis of the burning tank. At an air flow velocity of 6.5 m/s the temperature at the top of the adjacent tank reaches 176 °C, and at 9 m/s – 426 °C, which is higher than the autoignition temperature of oil, which is within 222–256 °C, there by creating a threat of fire spread. The study has defined the maximum distances from the burning VSTWFR-65000 for the safe presence of people, amounting to 47.3; 48.9; 50.2; 53.4; 55.7; 56.8; 59.4 m for wind speed of classes 0, 1, 2, 3, 4, 5 and 6 respectively.

Влияние ограждений вертикальных стальных резервуаров с бензином на снижение потенциального пожарного риска

Purpose. The article discusses the procedure and features of developing logical event trees, which are an integral part of the fire hazard analysis in the assessment of fire risks at industrial facilities and are widely applied at various facilities to be protected, using the example of emergency situations at typical vertical steel tanks (VST) with gasoline. The authors demonstrate the effect of the standard earthen embankment and the enclosing wall with a wave deflector for a VST on reducing the potential fire risk. Methods. The methodological and regulatory basis for developing logical event trees and assessing fire risk are the requirements of the Federal Law of the Russian Federation No. 123-FZ dated 22.07.2008 “Technical Regulations on Fire Safety Requirements”, as well as the “Methodology for Determining Estimated Values of Fire Risk at Industrial Facilities”, approved by Order of EMERCOM of Russia No. 404 dated 10.07.2009. Findings. The paper presents complete logical event trees that can be implemented on RVSs with gasoline, and provides information on the justification of the frequency rate of a fire hazard, even if its standard values are absent. The efficiency of using an enclosing wall with a wave deflector in tank farms is substantiated. For the considered RVS-20000 with gasoline, the use of such a barrier can reduce the potential fire risk in the range from 10–6 to 10–8 year–1 at the corresponding distances from the tank from 7.7 to 13 times, compared with the application of a standard earthen embankment. Research application field. The developed logical event trees and proposals for constructing enclosing walls with a wave deflector in tank farms can be used in activities of EMERCOM of Russia, expert organizations, research and design institutes, as well as higher education institutions and other educational organizations, when resolving issues of confirming the compliance of industrial facilities to be protected with the required level of fire safety based on fire risk assessment within the framework of performing final qualification papers and developing special technical conditions. Conclusions. The use of the obtained results in the educational process will improve the quality of training students who are competent in the following areas: methods of assessing the compliance of the facility to be protected with the requirements of regulations and normative documents; methods for determining the calculated values of fire risk; systems for ensuring fire safety of facilities to be protected aimed at reducing fire risk.

Improvement of the design of a vertical steel tank for oil and petroleum products

The age of vertical steel tanks (oil tank) in oil companies 20 – 30 years. Periodic inspections shall be carried out to prevent tank failure. Periodic levelling is carried out to prevent a reservoir from falling due to precipitation. The technical solution consists in eliminating the uneven precipitation. The bottom of the reservoir is levelled by lifting said reservoir with jacks which can be mounted directly in special niches. The main advantages of the new design are low equipment costs, reliability of the used tank design and long-term operation without foundation sludge. This construction represents a really rational approach to solving the problem of foundation sediment.

EXPERIMENTAL STUDIES OF PRESSURE CHANGES IN THE GAS SPACE OF OIL STORAGE TANKS

Vertical steel tanks are a significant part of the main oil pipelines in terms of cost, purpose, and environmental impact. More than 30 % of vertical steel tanks will never be equipped with pontoons and floating roofs, but will be equipped with breathing valves, which are an ineffective means of reducing losses. The creation of excess pressure in the gas space of the tank requires control over it, while for tanks that have been in operation for a long time, a decrease in excess pressure and vacuum is allowed due to leakage of individual tank components. During the study, experiments were carried out to determine the change in pressure on 6 model tanks with a changing and stable filling level. As a result, it was revealed that it is necessary to analyze the change in pressure in the gas space of the reservoir by the operating organization online. This will allow timely detection of deviations in the operation of the tank and take the necessary action.

EFFICIENCY OF TREAD ALLOYS FOR VERTICAL STEEL TANKS

The article discusses the use of various protector alloys made of magnesium and aluminum to protect vertical steel tanks when storing oil and oil products. Characteristics of protector alloys made of magnesium or aluminium and their alloys are shown. Data on the rate of selfdissolution of protector alloys depending on the degree of mineralization of bottom water are given. Gravimetric tests were used to calculate the mass index of the corrosion rate and electrochemical tests were used to calculate the efficiency of the anode current density. An empirical equation is shown by which the self-dissolution rate of protector alloys made of aluminum and magnesium alloys can be calculated, and empirical coefficients are given for the case of using protector alloys considered in the work. The obtained empirical dependence will make it possible to predict the rate of self-dissolution of aluminum and magnesium protector alloys. The efficiency of magnesium and aluminum protector alloys was analyzed and the dependence of the efficiency factor on the anode current density for magnesium and aluminum protector alloys was shown. Shows the effectiveness of using aluminum protector alloys to protect vertical steel tanks. It was concluded that the use of aluminum protector alloys is more efficient, since their efficiency is higher than that of magnesium alloys, this is clearly seen in the graph presented in the work on the dependence of the efficiency on the total mineralization of bottom water. The results of the work can be used in the design of protector protection for vertical steel tanks pre-designated for storage of oil and oil products containing produced water of various salinity.

Oscillation frequencies of the reinforced wall of a steel vertical cylindrical tank for petroleum products depending on winding pre-tension

This paper reports a study of the frequencies and vibration modes of a vertical steel tank with a variable wall thickness in the ANSYS software suite using a finite-element model of vibrations of a tank with a volume of 3000 m3 for oil and petroleum products, hardened by a prestressed winding. The simulation was carried out for two variants of fixing the upper edge of the tank wall, which correspond to cases of absence or presence of tank coating. The estimation cases for the coefficients of the tension force of the wire relative to its tensile strength were investigated: at k1=0.2; k2=0.4; k3=0.6 and k4=0.8. Variation studies were carried out both taking into account the additional loads caused by the action of hydrostatic pressure from the maximum and half poured oil into the tank, and without oil. The magnitude of changes in the vibration frequencies of the tank wall without the influence of the coating varies within 12–27 % and when taking into account the influence of tank coating, 21–62 %, depending on the degree of filling of the tank. The revealed pattern relates to the fact that a decrease in the tension force of the filament in the winding leads to an increase in the frequency of oscillations. Thus, pre-stress can be applied to regulate the oscillation frequency of the tank wall. By decreasing which in the winding, it is possible to increase the natural frequencies of the wall and to lower the frequencies through an increase in the prestress. The research results can be used in the future as anti-seismic measures in the design and construction of steel vertical cylindrical tanks, as well as to improve the strength characteristics of existing cylindrical structures

Finite element modelling of the contact between shell structure and foundation

This paper presents the problem of modelling of a shell structure as a vertical steel tank with a volume of 20000 cubic meters under a combination of static loads. The total height of the cylindrical wall of the tank is 17880 mm, and its diameter is 39900 mm. The wall thicknesses have been determined according to the design requirements of strength and buckling. The geometric model of the object has an axisymmetric form. The task is to perform the analysis of the stress-deformed state of the cylindrical wall and the contact zone of the wall with the foundation under different loads. The type of the contact is "Frictional" with a coefficient of friction equal to 0.45. The lower part of the foundation has been fixed. We have also restricted the radial movement of the upper part of the tank. Modelling has been carried out using the ANSYS simulation software. In three-dimensional modelling, finite elements of the SHELL281 type have been used. When solving an axisymmetric problem in a two-dimensional formulation, we have used PLANE183 finite elements. We have verified the model by comparing the radial displacements of the shell obtained using numerical simulation with the values calculated analytically. The discrepancy between the data does not exceed 5%, which indicates the adequacy of the finite element model. We have performed the analysis for non-standard operating conditions, which suppose the excessive internal pressure in the tank (2.5 and 3 kPa against 2 kPa under normal conditions). The contact "bottom - foundation" with a one-way connection allows separation of the bottom from the foundation. The complete detachment occurs under a specific combination of excessive and hydrostatic pressures. For certain levels of liquid in the tank, the gap decreases almost to zero, followed by a noticeable increase. This rapid change can be explained by the fact that with an increase in the hydrostatic pressure the effect of separation due to the excessive pressure decreases, and then the process of internal separation occurs, caused by the increasing moment from hydrostatic pressure.

Experimental Tests in Production of Ready-to-Drink Primitive Wine with Different Modes of Circulation of the Fermenting Must

Energy efficiency is an increasingly important issue in the wine industry worldwide. The focus on quality in wine production has led to increased attention being paid to the product at all stages of processing. The interaction with mechanical components is considered one of the possible critical points in the vinification process, and it becomes fundamental to optimize specific points in the wine production line using the best extraction technique. Therefore, in this work, experimental monitoring of two types of product circulation systems in fermentation was carried out in a winery in Puglia (Italy). In particular, the functional performance and energy consumption of two identical vinification lines were monitored, in which the only variables were two types of circulating systems for the fermenting must: pump-over and pneumatic cap breaking. During the trials, a homogeneous batch of Primitivo grapes was processed, hand-picked and taken to the winery within 1 h of harvesting, where a “ready-to-drink” wine production line was set up. A net quantity of 1000 hL of destemmed grapes was placed in two identical vertical steel tanks. Both wine tanks were monitored and equipped with an automated assembly system and a pneumatic marc breaker. Once both tanks were filled, a first break of the cap was carried out using a pneumatic system in one tank and an automatic pump-over in the other. For the grapes and type of wine studied, the pneumatic system showed better functional performance in terms of vinification speed and energy consumption; on the other hand, the pump-over system performed better in analytical terms. Finally, the results obtained highlight the need for further studies on equipment design to obtain significant benefits in terms of wine production costs while maintaining the quality standards required for “ready-to-drink” wines.

Selection of equipment for oil tank repair in northern conditions

Introduction. The oil industry is a key component of the economy of the Russian Federation. A large number of tanks are used to store oil, each of which needs timely repair. According to the results of some research, almost half of the accidents are caused by excess uneven settlement of the tank, which causes premature failure. To restore the serviceable and operable condition of the tanks, it is necessary to carry out repair work, the quality and efficiency of which depends on the repair equipment used. An urgent task is to justify the choice of equipment for the repair of tanks, in particular, steel tanks of a vertical type.Methods and materials. A review of the different types of tanks was carried out and showed that vertical steel tanks are the most widely used. One of the ways to eliminate the uneven settlement of the tank is to raise it with the help of jacks and form a new base with the elimination of the slope.Results. The repair process for a 10,000 m3 steel vertical tank was considered. The values of the mass of the tank were obtained when filling with liquid petroleum products at 1% of the maximum occupancy. The value of the load on one lifting device is obtained. The design of the device structure and the strength calculation in the Compass 3D program were completed.Сonclusions. The most efficient type of the lift from the existing ones was determined, and its design was modernized. The strength calculation showed that the hydraulic lift is efficient under the given conditions.

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

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.

Взаимосвязь конденсации влаги и образования пирофорных соединений в парогазовом пространстве резервуаров с сернистой нефтью

Purpose. When storing sulfurous oil in vertical steel tanks, pyrophoric corrosive deposits are formed on their inner surface after a while, and they are capable to self-ignite under certain conditions. It is assumed that the rate of corrosion and that of forming pyrophoric deposits will depend on the humidity of the steam-gas medium inside the vertical steel tank and the conditions of its water fraction condensation on the oil tank inner surface. The main purpose of the research is to determine humidity impact on the inner surface of the roof and upper belts of tanks with sulfurous oil on the rate of corrosion and growth of pyrophoric compounds. Methods. To study the relationship between the humidity of the inner surface of the tanks with sulfurous oil, the temperature regime inside and outside the vertical steel tank and the growth rate of pyrophoric deposits, the method of experimental data analysis was used. Experimental results were obtained using an experimental method consisting of full-scale testing of low-carbon steel samples in tanks with sulfurous oil. Findings. The dependence of the amount of moisture and that of pyrophoric corrosive deposits formed on the inner surface of the tank with sulfurous oil on the type of the stored product and the season of year is revealed. A direct correlation is obtained between the amount of pyrophores formed and the amount of condensed moisture. Research application field. The results can be used in planning activities to ensure fire safety at the facilities of the oil and gas industry, as well as to ensure fire protection of vertical steel oil tanks. Conclusions. The results of the study allowed the authors to draw a number of the following conclusions: 1) when the inner surface of oil tanks comes into contact with the steam-gas medium, moisture condensation and the formation of pyrophoric deposits occur on the metal surface; 2) there is a correlation between the rate of pyrophoric deposits formation and the humidity of the tanks’ inner surface that are in contact with the steam-gas medium – the higher the humidity the greater the rate of pyrophoric deposits formation; 3) the growth rate of pyrophoric deposits is determined by the conditions of heat transfer on the tanks surface and is minimal at similar temperatures inside and outside the tanks, which are typical for the summer months and sunny spring-winter days; 4) high humidity of the tanks’ roof inner surface suggests the possibility of using tread protection to reduce the rate of pyrophoric deposits formation.

Анализ методов оценки площади пролива жидкости при квазимгновенном разрушении резервуара

Introduction. The normative method provides for the estimation of the spill area of flammable liquid in the case of quasi-instantaneous destruction of a vertical steel tank taking into account its spread both within the boundaries of the fence and outside it with a possible partial overflow with spreading over the surface depending on the spill factor. At the same time, the shape of the area of the liquid spill outside the fence is conservatively taken to be equally distributed along its entire perimeter, acquiring the outlines of a super ellipse. However, an analysis of the statistics of destruction of vertical steel tank showed that the actual areas of the straits had geometric shapes that differed significantly from the normative ones, and their quantitative value was mainly influenced by the slope of the terrain, which is not taken into account in the method. Thus, it is relevant to analyze the results of the assessment of the desired shape and area of the liquid spill, obtained on the basis of the normative method and the proposed alternative, which is based on the processing of statistical data on tank failures. Goals and objectives. To propose an alternative method for estimating the area of the spillage of flammable liquid and its shape in the quasi-instantaneous destruction of vertical steel tank. To develop a computer program "RVS - Wave". do a verification of the method based on a comparative analysis of the results with the actual area of the strait during the destruction of vertical steel tank RVS-2000 with bitumen. Methods. To develop an alternative method, data on the consequences of the destruction of the vertical steel tank at production facilities for the period from 1951 to 2010 were collected, analyzed, summarized and statistically processed. Methods of empirical research were also used: observation, experiment, comparison, description, measurement. Results and discussion. The use of the provisions of the alternative method makes it possible to obtain more reliable results, both in assessing the area of the liquid spill during the destruction of vertical steel tank, and in its geometric shape, and the developed program "RVS - Wave", significantly reduce the time for performing multivariate calculations of the desired parameters, depending on the direction of destruction of vertical steel tank and slope of the terrain. Conclusion. The proposed alternative method can be successfully applied to oil and petroleum product storage facilities in vertical steel tank in the classification of a possible emergency situation, the development of plans for the prevention and elimination of oil or oil spills, fire extinguishing plans, the assessment of fire and industrial risks, including for the purpose of developing additional fire prevention measures in advance and determining the number of forces and means necessary to localize the predicted accident and elimination of its consequences. Keywords: tank; quasi-instantaneous destruction; breakthrough wave; earthen collapse; enclosing wall; overflow; area of the strait; evaluation methods; analysis.

Анализ нормативного метода оценки доли перелившейся через ограждение жидкости при квазимгновенном разрушении резервуара

Purpose. When assessing fire risks at oil and petroleum product storage facilities, it is necessary, alongside, to consider the scenario of a liquid spill in case of quasi-explosive tank destruction. The breakthrough wave formed in this case is able to overflow through safety enclosure. The normative method allows assessing the proportion of overflowing liquid only through the enclosure in the form of vertical protective walls, while earth dikes of trapezoidal shape with different slope angles have become most widespread at the specified objects of protection. The article justifies the relevance of continuing the research on assessing the proportion of liquid overflowing through enclosures of various geometric shapes in case of quasi-explosive destruction of the tank. Methods. Statistical data analysis methods on actual quasi-explosive tank failures at production facilities in Russia and abroad have been used, including a full-scale experiment on the destruction of VST-700 with water, as well as observations, comparisons, descriptions, and generalizations. Findings. It is shown that the definition of the term quasi-explosive tank failure requires additions and clarifications based on statistical data analysis on the destruction of vertical steel tanks. The mechanism for opening the wall of a vertical steel tank has been clarified, which leads to the occurrence of a breakthrough wave, and its characteristics has been given. The application limitations of the existing method for estimating the proportion of overflowing liquid only through the enclosures in the form of vertical protective walls have been justified. Research application field. The results of the study can be used for developing the tenets of the method for determining fire risk design values at production facilities when considering a scenario related to a liquid spill in case of quasi-explosive destruction of a vertical steel tank. Conclusions. Based on the analysis results of the tenets of the method under consideration, the necessity to continue studies aimed at assessing the proportion of liquid overflowing through enclosures of various geometrical shapes during tank destruction, the value of which is needed for quantitative assessment of fire risks at production facilities, has been justified.

Определение объемов изысканий при строительстве вертикальных стальных резервуаров на слабонесущих грунтах

Определение объемов изысканий при строительстве вертикальных стальных резервуаров на слабонесущих грунтах

ОЦЕНКА ИНТЕНСИВНОСТИ СЕЙСМИЧЕСКИХ НАГРУЗОК ОТ ВЗРЫВНЫХ РАБОТ НА ОХРАНЯЕМЫЕ ОБЪЕКТЫ НАКЫНСКОЙ НЕФТЕБАЗЫ

In order to assess the intensity of seismic loads from blasting operations on a deep foundation of vertical steel tanks RVS-2000 installed in 2021 for storing petroleum products, the authors performed instrumental measurement of ground vibrations at the foundations of the protected facilities. The actual load on protected facilities was determined using seismometric methods, according to the MSK-64 seismic intensity scale in full-scale conditions of drilling and blasting operations at the Mirny-Nyurba MPD open pits. Based on the results of the study, recommendations were developed to determine the parameters of the drilling and blasting operations that ensure the seismic safety of the RVS-2000 tanks of the Nakyn oil depot.

Features of extinguishing fires in the oil and gas industry by feeding foam into a layer of flammable liquid (in Kazakh language)

This article describes a method for extinguishing fires of oil and petroleum products in vertical steel tanks by feeding foam to form a low-layer film directly into the fuel layer at the bottom of the tank. The problems of extinguishing fires in tanks with a floating roof or on a pontoon when extinguishing fires in a storey way are briefly described. The main problems: contamination of the foam with oil and petroleum products, the time of lifting the foam to the surface of the tank, the appearance of “pockets” inaccessible for extinguishing, etc. The results of studies of the main modern systems for ensuring fire safety of oil and gas industry facilities, such as: transportation, processing and storage, are shown. The results of the study of the fire extinguishing process with film-forming foam in tanks, as well as the study of the properties of fluorosynthetic foams, are described. Examples of combined fire safety systems on pontoon tanks are also given.