• Energy Research
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In 2011-2012 The parity of the cost of energy of thermal power plants on fossil fuels and the cost of energy from wind farms and solar power stations had come. Since 2017, the capacities of introduced renewable energy sources in the world have exceeded the volumes of commissioned capacities of traditional energy. The transition from traditional energy technologies to renewable energy sources (RES), which are becoming more profitable from an economic point of view and can minimize the negative impact of energy on the environment, is being phased. This article gives a review of the prospects of application of the combined schemes using renewable energy sources to generate energy. The paper discusses the most important areas of energy development in our country.

The work is d to improving methods for calculating the cooling system of a microturbine with a rotor on air bearings. When designing gas turbines, it is important to integrate gas-dynamic calculations with thermal finite-element calculations. In practice, the conjugation of temperature fields in solids and liquids, as well as the transfer of thermal loads between the media are carried out using several approaches: direct, non-conjugate and sequential coupled. Numerical simulation of the coupled heat transfer in a cavity formed by the gap between the rotor and stator is carried out. To calculate the flow characteristics of a viscous compressible fluid and heat transfer. The degree of influence on the results of the type of turbulence model used, the influence of taking into account the conjugate heat transfer, is studied. The effect of the mass flow rate of the cooler on the flow structure and the cooling efficiency of the walls of the rotor and stator is investigated. A comparison is made with experimental data. Numerical experiments have shown that in typical cases the flow in the cavity is turbulent. The cooling efficiency has a limit on the flow rate of the cooler. The temperature distribution along the length of the rotor has a noticeable minimum in the region of the middle of the length of the rotor. The significance of the obtained results lies in the fact that the choice of the turbulence model weakly affects the calculation results and taking into account the conjugate nature of heat transfer is necessary.

The results of computer simulation of the processes of incineration of low-grade solid fuelpulverized peat with a moisture content of 40%, an ash content of 6% are given. It has been determined the fields of distribution of temperature, velocity of gases and particles in the volume and at the outlet from the furnace. The three-dimensional temperature distribution in the combustion chamber indicates high-temperature combustion of peat particles at temperatures above 1700°C with liquid ash removal in the lower part of the furnace. It has been determined that when the furnace is cooled, it is not ensured combustion of the fuel completely. The value of the swirling flow rate at the outlet from the furnace (up to 370 m/s) ensures the efficiency of separation of fuel particles, reducing heat losses from mechanical underburning. It is determined that the concentration of oxygen is close to zero over the entire height of the furnace, at an outlet from the furnace the oxygen concentration is 5...6%, since oxygen is supplied with excess (αв=1,2). The results of a numerical study showed that the diameter of peat particles affects the process of their combustion: coke particles with an initial diameter of 25 mkm to 250 mkm burn out by 96%. With an increase in particle diameter up to 1000 mkm, the degree of burn-out of coke decreases, but at the same time their removal decreases. It is shown that the furnace ensures the completeness of combustion of peat particles of peat 99.8%, volatiles is 100%.

The basic elements of design SIIT are electrode materials that have the function of storing electric energy and high surface current collecting elements by transmitting this energy to the load. Therefore, the first task is to choose a design SIIT design and technology of electrode materials. Another fundamental element is the electrolyte, ensuring the formation of the electrical double layer on the surface of the highly electrode materials and the transfer of electric charge carriers within the electrolytic cell. It is proposed to use a polymer electrolyte, which in comparison with aqueous electrolyte has a significantly higher operating voltage. In addition to the electrolyte composition and its manufacturing technology to develop the technology necessary to impregnate the electrolyte electrode materials that will ensure maximum use of high surface area electrode materials. The third element is the SIIT housing and electrical contacts to ensure his switching to other functional units of electronic equipment (REA), including the management of SIIT, which performs the function of monitoring and optimization of its functioning.

The aim of this work is to study the influence of technological defects in stator windings electrical insulation system on the inception of partial discharges in the stator slot of air-cooled electric rotating machines. By means of Comsol Multiphysics finite-element modeling software the electrophysical processes in high-voltage stator insulation with corona-protection coatings are numerically studied for both Resin-Rich (RR) and vacuum pressure impregnation (VPI) technologies. The most important results are the conclusions made about the possibility of slot partial discharges in the insulation system of stator windings, taking into account the possible types and sizes of technological defects of the anticorona coating in the slot area. The verification of the results of mathematical modeling by experimental study of slot partial discharges on test samples with artificial defects of anti-corona coatings made possible to establish the most dangerous types and geometric sizes of defects, which lead to the inception of slot partial discharges, which determined the practical significance of the results. Quantitative dependencies between the geometric dimensions of coating defects and the characteristics of slot partial discharges (inception voltage, maximum apparent charge, and average current) are experimentally established. The obtained data have practical importance for the development of the optimal technology for manufacturing the system of electrical insulation of the stator winding of high-voltage air-cooled electric machines.

The evaluation of the possibility of using electromagnetic stirrers for dissimilar mixtures in various technological processes requires the study of their work under load conditions. The load mode of the agitator is ensured by the needle ferromagnetic elements moving inside a cylindrical working chamber under the influence of a rotating magnetic field, whose effectiveness can be predicted by analyzing the magnitude and nature of changes at the electromagnetic moment. The magnetic field ensures ordering of the ferromagnetic elements, therefore the magnetic permeability in it along the longitudinal and transverse axes becomes different. Due to the anisotropy of the magnetic properties of the composite medium in the working chamber, strong influences arise on this medium, based on the magnetic tension forces acting on the ferromagnetic elements. The purpose of this work was to present the method of calculation of the electromagnetic moment and determination of its dependence on the angular displacement of the rotating magnetic field of the inductor. The distribution of the magnetic induction inside the working chamber in the idle and load modes was compared, it gave an idea of the distribution of the magnetic field lines in those modes, set out the basic principles for calculation of the angular characteristics of the torque of the electromagnetic stirrer. The proposed method was based on the multi-position numerical calculations of the magnetic fields in the FEMM software package. Comparative calculations of the angular characteristics of the torque were performed at different magnetic permeabilities of the composite medium in the working chamber.