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Wind energy is an efficient and environmentally friendly method of generating electricity. The search and development of methods to improve the efficiency of conversion and use of wind energy is a science-intensive and important area. The main difficulty in the practical application of wind energy is the variability of speed, the wind changes its activity during the day and for very short periods of time (instantaneous chaotic speed pulsations, storm gusts of wind). The paper considers a control system made using a fuzzy logic apparatus, which will allow obtaining the maximum possible power of a wind power plant (WPP) in the operating winds mode and nominal power in the limited mode. The control system is adaptive to natural features and is a part of a digital intelligent energy production technology based on the use of wind. [ABSTRACT FROM AUTHOR]

The transition to low-carbon development, to reduce the negative impact on the environment, mainly affects the energy sector. Natural gas occupies a stable position of the demand of the Unified Energy System of Russia for 2021-2026 in fossil fuel. When natural gas is burned, thermal nitrogen oxides (hereinafter referred to as NOx) are predominantly formed in power-generating boiler of thermal power plants. This article presents the modeling and study of the natural gas combustion process with the organization of flue gas recirculation to the active burning zone on the example of a power-generating boiler of the TGMT-464 type, using the ANSYS Fluent software package. The paper presents a model and graphs of the temperature and NOx content distribution in the active burning zone with a change in the proportion of flue gas recirculation from 0 to 22%. The decrease in the emission of harmful substances is explained by the decrease in the peak flame temperature in the active burning zone, which is the main indicator of the formation of NOx. The decrease in temperature in the active burning zone is explained by an increase in the volume of gases in the combustion zone. The article is intended for postgraduate, candidate for a doctor's degree interested in the development of methods for suppressing the formation of NOx in the combustion products power-generating boiler at TPPs. [ABSTRACT FROM AUTHOR]

Mathematical modeling is the main tool for studying complex gas-dynamic processes occurring in non-stationary conditions. It allows performing multiply research and development of engineering solutions with reliable accuracy. The search and development of controlling methods for the boundary layer of gas flows is a promising area of research, allowing intensify or reduce exchange processes in the boundary layer of power plants used in various fields of industry in our country, such as: energy, aircraft construction, shipbuilding. Method based on the use of the damping surface is a modern and effective control method. The damping surface effect is expressed in a decrease in the intensity of the turbulent vortices generation, which leads to an increase in the velocity in the boundary layer, a decrease in drag friction and heat transfer. The development of technology will make it possible to work out the engineering solutions for efficient and resource-saving energy. The studies were carried out using the ANSYS Fluent software package, which allows modeling the thermal and turbulent processes in the boundary layer using the k – ɛ turbulence model (realizable) with high accuracy. [ABSTRACT FROM AUTHOR]

Boundary layer control on a surface streamlined by high-velocity gas flows is an important task in modern technology. There is a wide range of active and passive flow control methods used to reduce frictional drag, heat transfer, turbulization, mainly in incompressible turbulent boundary layers. The development of science and technology does not stand still, and in modern conditions, given the need to improve the efficiency of equipment, reduce energy consumption in production and fulfill a number of tasks to modernize the energy complex, set by the Ministry of Energy, in the draft energy strategy of Russia for the period up to 2030, it is necessary to develop new and efficient ways of managing the boundary layer to create efficient and resource-saving energy. The paper proposes a method for mathematical modeling of turbulent transfer on a damping surface. The method allows one to study the effect of the damping surface on the exchange processes occurring in the boundary layer in the range of Re numbers from 1 · 105 to 4 · 107. [ABSTRACT FROM AUTHOR]

The search and development of alternative energy sources for human life is a priority task for modern society. One of the promising directions is the use of biogas as a source of thermal energy for power plants. It is established that the main difference between biogas and natural gas is caused by the presence of more than 30% of carbon dioxide in its composition, which affects the density, calorific value and speed of flame propagation. To burn biogas in modern power plants that use natural gas, it is necessary to modify the burner devices. For qualitative modification of burner devices, it is necessary to have theoretical data on effective modes of biogas combustion. In combustion, we present a model of turbulence k-s (realizable), which allows us to model the combustion of natural gas and biogas with tangential air swirl. The paper presents qualitative characteristics of biogas that allow us to analyze and develop a theory about efficient combustion of biogas in power plants. [ABSTRACT FROM AUTHOR]

The fundamental tool for studying complex gas-dynamic processes occurring in the boundary layer under non- stationary conditions is mathematical modeling, which allows for reliable accuracy to conduct comprehensive research and development of technical solutions necessary to create an efficient and resource-saving energy. A promising area of research is the search and development of methods for managing the boundary layer of gas flows. To date, there are many methods for managing the boundary layer that allow to intensify or reduce exchange processes in the boundary layer [1], including in power plants. One of the most effective, but little-studied methods is the method of passive influence on the boundary layer of the gas flow, based on the use of a damping surface [2]. The impact of the damping surface leads to a decrease in the intensity of generation of turbulent vortices, which in turn reduces the friction resistance and heat exchange in the boundary layer [3]. The paper presents a method for modeling a turbulent boundary layer, which allows calculating the impact of the damping surface on the dynamic processes occurring in the boundary layer of the gas flow. In addition, the modeling technique includes the ability to study the boundary layer for the most common gases in the technology, such as air and The paper presents the results of a numerical study of the boundary layer on a damping and smooth surface in graphical form. Research conditions: a flat surface with a high-speed gas flow was simulated. [ABSTRACT FROM AUTHOR]

Prevention of further atmospheric air pollution and reduction of toxic substances emission is one of the goals of state policy in the field of energy. In this regard, the search for new solutions that prevent negative impact on the environment is one of the priority tasks for modern society. An alternative, but less efficient fuel compared to natural gas is biogas extracted from organic waste. The high content of carbon dioxide in biogas reduces the calorific value, while flame detachment from the burner is also observed. One of the promising options for reducing the negative impact of energy on the environment is the combined burning of natural gas and biogas. For the combined burning of natural gas and biogas in operating power-generating boiler, it is necessary to reconstruct the burner devices installed on them. For a high-quality reconstruction of burner devices, it is important to have theoretical data on the effect of combustion combinations on the content of toxic combustion products in the flue gases of power-generating boilers. In this paper, a turbulence model k - ε (realizable) is presented, which allows simulating the combustion process of a fuel-air mixture. The quantitative content of NOx, CO2 in the products of combustion of fuel combinations - natural gas, biogas, natural gas / biogas is presented. [ABSTRACT FROM AUTHOR]

The paper presents a method of mathematical modeling of turbulent transfer in the boundary layer on a surface with hemispherical damping cavities, and presents the results of a numerical study of the effects of damping cavities. Hemispherical damping cavities contribute to the reduction of turbulent energy in the boundary layer, which leads to a decrease in turbulent friction and heat exchange in the boundary layer, thus, mathematical modeling of the effects of hemispherical damping cavities is relevant. [ABSTRACT FROM AUTHOR]

The numerical investigation of thermal protection efficiency on the surface containing regular hemispherical cavities is carried out under the condition of high-speed dispersed flows around the surface. It is revealed that the hemispherical damping cavities largely stabilize the thermal curtain on the surface, reducing the temperature of the latter to 25 degrees and increasing the efficiency of the curtain to 0.12. The cooling efficiency of the surface is significantly reduced at the presence of particles within the flow, and an increase in the particle concentration leads to a decrease in the thermal protection of the surface. New technical solutions with damping cavities are proposed to increase the efficiency of thermal protection of the surface of the flame tube of a gas turbine engine (RF patent No 173450). [ABSTRACT FROM AUTHOR]

The search and practical implementation of the methods for controlling turbulent transport is hindered by the lack of a theoretical basis that would justify the possibility of controlling the boundary layer. Theoretical bases of turbulent transport control have been developed, which make it possible to investigate the non-stationary boundary layer in a homogeneous gradient flow. A mathematical model and a method for calculating turbulent transport in the boundary layer under the action of hemispherical damping cavities are proposed. The results of a numerical study that allow one to determine the parameters of the boundary layer and to carry out an analysis of the effectiveness of boundary layer control during the action of hemispherical damping cavities on the non-stationary boundary layer are presented. [ABSTRACT FROM AUTHOR]

The numerical investigation of the turbulent flow with the impacts, based on a modified Prandtl mixing-length model with using of the analysis of pulsations of pressure, calculation of structure and a friction factor of a turbulent flow is made. These results under the study allowed us to propose a new design of a cooled turbine blade and gas turbine mobile. The turbine blade comprises a combined cooling and cylindrical cavity on the blade surface, and on the inner surfaces of the cooling channels too damping cavity located on the guide vanes of the compressor of a gas turbine engine, increase the supply of gas-dynamic stability of the compressor of a gas turbine engine, reduce the resistance of the guide blades, and increase the efficiency of the turbine engine. [ABSTRACT FROM AUTHOR]

The search for new solutions in the field of energy that prevent negative impact on the environment is one of the priority tasks for modern society. Natural gas takes a stable position of the unified energy system demand for fossil fuels in Russia. A possible alternative fuel extracted from organic waste is biogas. Biogas has a high content of carbon dioxide, which affects the rate of flame propagation and a lower methane content, which reduces the heat of combustion. However, the combined combustion of natural gas and biogas, provided that the fuel mixture with the oxidizing agent is well mixed, can allow, on the one hand, to reduce the maximum adiabatic temperature in the combustion chamber of power-generating boiler of thermal power plants, and on the other, to increase the stability of biogas combustion. For the combined combustion of natural gas and biogas in operating power-generating boiler, it is necessary to reconstruct the existing burner devices. For a high-quality reconstruction of burner devices capable of providing stable and low-toxic fuel combustion, it is important to have theoretical data on the effect of combustion of combinations of organic fuels on the temperature distribution in the combustion zone and its maximum value. In this paper, the turbulence model k - ε (realizable) is presented, which allows simulating the combustion process of a fuel-air mixture. The temperature distribution in the zone of active combustion during combustion of the fuel - natural gas, biogas, natural gas/biogas combinations is presented. [ABSTRACT FROM AUTHOR]