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1
Content available Minimization of Energy Consumption of Vortex Devices for Granulation of Materials
Pavlenko Anatoliy, Cheilytko Andrii, Ilin Sergii, Karpenko Hanna
Rocznik Ochrona Środowiska
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2023
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Tom 25
198--207
EN
The article considers the possibility of efficient energy and environmental use of vortex devices for the granulation of solids. The factors influencing the energy consumption for generating a vortex flow with dispersed solid inclusions are analysed. A mathematical model for calculating the aerodynamic drag of a vortex apparatus in a clean gas flow, which was used in computer modelling, is presented. The main dependencies for determining the influence of the geometric dimensions of the vortex on its aerodynamic drag are also given. An analytical solution to the problem of minimising the aerodynamic drag of a vortex apparatus during the movement of a dispersed medium is considered. The forces acting on the particles in the cyclone chamber during interaction with the gas are analysed. In this paper, a general method for calculating the parameters of cyclone-vortex devices for dispersed media using the basic equations of hydrodynamics and gas dynamics is developed. The solution approach used in this paper can be extended to other vortex devices not considered in this work.
2
Content available remote CFD simulation of airflow in a new receiver concept for solar tower
Cheilytko Andrii, Nohutcu Oguzhan, Schwarzbözl Peter, Broeske Robin Tim
Journal of New Technologies in Environmental Science
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2023
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Vol. 7, nr 3
83--98
EN
Open cavity solar receivers play an important role in concentrated solar power (CSP) systems and hold great promise, particularly in scenarios where their ability to absorb high fluxes at very high temperatures yields beneficial results. This intense concentration of sunlight can be used to produce electricity through various means, such as generating steam to drive a turbine. The efficiency of the open volumetric receiver concept relies heavily on the air return ratio (ARR) which refers to the proportion of air recirculated and returned to the receiver. A high ARR contributes to high receiver efficiencies, as with rising ARR, the reused part of the enthalpy of warm air increases. This paper deals with the design and simulation of a new receiver concept with a conical cavity and square cross-section. The objective is to identify the most effective design arrangement for the square-cone structure, considering different depths, that maximizes both the air return ratio (ARR) and thermal efficiency. The findings demonstrate that increasing the depth of the mentioned receiver leads to a rise in the ARR, up to a certain threshold which can reach values up to 94.53%, beyond which there is a subsequent decline in efficiency. Furthermore, this study examined how varying the amount of air passing through a specific section of the receiver across a defined area, along with the temperature changes in these sections, affected its operational efficiency.
3
Content available remote A new idea to increase the convective efficiency of a solar tower air receiver by creating a controlled vortex
Cheilytko Andrii
Journal of New Technologies in Environmental Science
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2023
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Vol. 7, nr 2
46--55
EN
Concentrated solar energy as a source of renewable energy has a high potential for solving the current energy crisis. The solar tower receiver is a crucial element of solar energy conversion efficiency. To increase the convective efficiency of the solar tower receiver, the idea of creating a vortex is proposed. The vortex is created either in the plane in front of the receiver, for flat receivers, or in the internal volume of the receiver, for cavity-type receivers. The calculation formulas for calculating the parameters of the controlled vortex are proposed and computer modeling is performed to determine the effectiveness of the proposed idea. The results of computer modeling confirmed the physical possibility of the controlled vortex formation in the receiver space and visually show the flow structure. Also, the general dependence of the air return coefficient in the VoCoRec receiver on the flow twist was found. Conclusions are drawn on the satisfactory results obtained and on the improvement of the existing model of the controlled vortex.
4
Content available remote Influence of structural characteristics of porous materials on the coefficient of thermal conductivity
Cheilytko Andrii
Journal of New Technologies in Environmental Science
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2022
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Vol. 6, nr 3
104--112
EN
The existing dependences of the effective coefficient of thermal conductivity of the material depending on the size and location of pores in it are analyzed and compared with each other and with previously obtained experimental data. It is shown that the resulting thermophysical properties of the material are affected not only by the porosity, but also by the location of the pores in the volume of the material. The disadvantages of the existing dependences of determining the effective thermal conductivity of the material on the type of porosity (both for porous material and for dispersed systems) are shown. Also, the most reliable dependences of the thermal conductivity coefficients on the porosity of dispersed systems for backfill materials and the need for their correction by empirical coefficients are determined. Complex indicators that fully describe the porous structure and on which the mathematical model of heat exchange processes in a porous medium should be based are proposed.
5
Content available remote Research of the question of increase of efficiency of cooling of the power equipment of hydroelectric power plants
Cheilytko Andrii, Ilin Sergii
Journal of New Technologies in Environmental Science
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2020
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Vol. 4, nr 1
22--29
EN
Improving the cooling efficiency of power transformer windings with a cross-sectional width of the radial channel less than 3 mm, by improving the geometric parameters of the cooling system while reducing the material consumption of the electric machine is an important area of research. Excess oil pressure in the winding channels increases with increasing serial number of the coil. It was found that with increasing oil velocity at the inlet to the horizontal channel, the values of excess pressure in it increase in quadratic degree. It is established that a lifting force occurs in the oil of the horizontal channel, as evidenced by the increase in excess pressure near the upper boundary of the channel. For the first time, an analytical dependence of the excess oil pressure in the radial channel of the disk winding of the power transformer on the oil flow rate at the inlet to this channel was obtained. The dependences of the excess pressure in horizontal channels with a cross-sectional width of 1 mm on the velocity of oil at the inlet to this channel were obtained, which allows to calculate the speed by which it is possible to organize through circulation of oil in the channel provided that excessive pressure in the channel is prevented. situations. A new mathematical model of interconnected heat exchange and hydrodynamic processes in the disk windings of a power transformer is proposed, which, unlike the existing ones, takes into account the width of the horizontal channel less than 3 mm, which allows to predict the heat distribution in the winding and determine possible locations overheating of coils and premature destruction of insulating materials.
6
Content available remote Research of environmental and technological problems of cavitation
Cheilytko Andrii, Osaul Alexandr, Ilin Sergii, Volkov Timofii
Journal of New Technologies in Environmental Science
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2020
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Vol. 4, nr 1
36--48
EN
The comparative analysis of systems of conversion of electric energy into mechanical and mechanical into thermal with realization of effect of cavitation in a stream of the liquid transported in a closed circuit is carried out. The optimal dimensions and relief of working surfaces of swirlers in tubular and rotary cavitators are determined. The regularities of the change of the coolant temperature depending on its nature, the intensity of cavitation, which is determined by the rotational-translational and rotational motion in cavitators of two types - tubular and rotary.
7
Content available remote Research of cyclone characteristics for dry cleaning of gases from dust
Cheilytko Andrii, Ilin Sergii
Journal of New Technologies in Environmental Science
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2020
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Vol. 4, nr 3
134--142
EN
The development and application of new, more efficient dust collection units that will help reduce emissions and conserve some very valuable resources for production is an important area of research. With the growth of innovation in technological enterprises, the number of harmful emissions into the atmosphere is growing. Thus, the ecological condition of the environment deteriorates. The basic analytical dependences which are necessary for construction of a technique of carrying out experiments and calculations of dust catching for concrete working conditions are developed. Methods of calculating cyclones as vortex devices and research of cyclone operation for air purification from dust were investigated. On the basis of the used basic theoretical positions of heat and mass transfer and thermodynamics at carrying out analytical researches the mathematical model was offered. Calculations of new designs of modern cyclones to obtain their geometric dimensions, resistance and dust capture efficiency were presented. Modern cyclones are designed to more effectively remove dust from the air during various types of work.
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