Wyniki wyszukiwania - BazTech

1

Energy-efficient renovation of an industrial hall into a biomass and biogas laboratory in the context of the EU Renovation Wave

Stepien Anna, Ciosek Anita, Piotrowski Jerzy Z., Pavlenko Anatoliy, Dachowski Ryszard

Budownictwo o Zoptymalizowanym Potencjale Energetycznym

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2025

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Vol. 14

198--207

EN

The construction sector currently accounts for one-third of EU CO2 emissions, and approx-imately 75 % of existing buildings are energy inefficient. According to research, 85 % - 95 % of existing buildings will still be standing in 2050. In October 2020, the European Commission presented a strategy called the Renovation Wave, which aims to increase the energy efficiency of buildings. The article includes an analysis of damage to an industrial facility in the context of thermal and humidity conditions, an example of modernization work for an industrial facility and its partial adaptation to a biomass, biogas, and biofuel laboratory. The facility is a single-story steel hall with ceramic brick infill, with plan dimensions of 12.5 × 31.0 m and a height of 7.2 m. It was necessary to perform a technical condition assessment, particularly of the construction materials, and an analysis of thermal and humidity conditions for the indicated scope of renovation work.

2

Influence of Ventilation Air Supply into the Space Between Two Glass Units on the Energy Characteristics of this Transparent System

Basok Borys, Pavlenko Anatoliy, Novikov Volodymyr, Koshlak Hanna, Goncharuk Svitlana, Davydenko Dmytro

Rocznik Ochrona Środowiska

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2024

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Tom 26

65--73

EN

By the method of numerical simulation, the heat transfer from the room to the environment through a system of two double-chamber windows, into the gap between which ventilation air from the room supplies, is being researched. Distributions of air velocity and temperature in the chambers of double-chamber windows and in the gap between double-chamber windows are determined. The influence of the flow of ventilation air entering the space between the double-chamber windows on the amount of heat transferred from the room to the space between windows through the inner window and the amount of heat removed from the gap to the environment through the external double-chamber window is investigated. The energy advantages of the method of removing ventilation air through the gap between double-chamber windows over the method of direct removal of ventilation air from the room to the environment are determined.

3

Heat Transfer Through a Three-chamber Glass Unit

Basok Borys, Davydenko Borys, Pavlenko Anatoliy, Goncharuk Svitlana, Koshlak Hanna, Lysenko Oksana

Rocznik Ochrona Środowiska

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2024

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Tom 26

49--55

EN

A well-known way to increase the thermal insulation properties of windows in buildings is to increase the number of glasses in a window or, what is the same, to increase the number of glass chambers in a glass unit. This method, in combination with low-emissivity coatings on the inner surfaces of glass, can provide a significant increase in the heat transfer resistance of window structures. The use of such windows in construction can significantly reduce heat loss from the premises in the winter, which leads to a reduction in energy costs for heating and increases the energy efficiency of the building. In this work, the characteristics of heat transfer through a three-chamber glass unit are studied using numerical modeling and experimental study. Options for the absence and presence of low-emissivity coatings on glass are considered. Changes in air velocity and temperature in the chambers are studied. Heat transfer resistance for three-chamber windows are calculated depending on the number of low-emissivity coatings on the glass.

4

CFD Simulation of Heat Transfer Through a Window Frame

Basok Borys, Novikov Volodymyr, Pavlenko Anatoliy, Davydenko Borys, Koshlak Hanna, Goncharuk Svitlana, Lysenko Oksana

Rocznik Ochrona Środowiska

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2024

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Tom 26

56--64

EN

The use of various coatings with a low level of radiation on the glass elements of window structures, filling the interglacial space in double-glazed windows with inert gases instead of air, increasing the number of cameras in double-glazed windows, other constructive measures aimed at improving the thermal insulation properties of double-glazed windows, led to a significant increase in the thermal resistance of the fenestration system. However, little has changed in the design and construction of window frames and edge areas adjacent to building facades, leaving these elements responsible for heat transfer through modern windows. In this article, with the help of three-dimensional CFD modeling, the thermal insulation properties of window frames are investigated in the most complete setting, taking into account the effect on heat transfer through the profile of the window frame of the adjacent walls of the building facade on one side and the double-glazed unit on the other. Finding out the thermal insulation parameters of the window frame will help to make appropriate changes in its design.

5

Characteristics of thermal modernization works and their impact on residential buildings in the 21st century

Piotrowski Jerzy Z., Pavlenko Anatoliy, Orman Łukasz J., Stępień Anna, Ciosek Anita

Materiały Budowlane

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2024

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nr 9

80--87

EN

The subject of the article was focused on aspects of energy-saving construction, and the main determinant was the heat transfer coefficient U, which determines the ability of heat energy to pass through building partitions. The scope of the article included conducting research for an existing two-story building before thermal modernization and after thermal modernization works in order to determine the economic and ecological benefits resulting from the works carried out. Thermal modernization works included: insulating external partitions with graphite polystyrene with a thermal conductivity coefficient of λ = 0.30 W/(m·K) and a layer thickness of 20 cm, replacing the coal boiler with a dual-function gas boiler with a hot water heater utility water, replacement of cast iron radiators with three-plate steel radiators and a ladder radiator in the bathroom, replacement of wooden double-glazed windows with a heat transfer coefficient Uw = 2.60 W/(m²·K) with wooden-aluminum windows with a heat transfer coefficient Uw = 0.95 W/(m²·K) with a two-chamber glass unit.

PL

Tematyka artykułu dotyczy budownictwa energooszczędnego, a głównym wyznacznikiem jest współczynnik przenikania ciepła U, który określa zdolność przenikania energii cieplnej przez przegrody budowlane. Przeprowadzono badania istniejącego budynku dwukondygnacyjnego przed termomodernizacją oraz po wykonaniu robót termomodernizacyjnych w celu określenia korzyści ekonomicznych i ekologicznych, wynikających z przeprowadzonych robót. Prace termomodernizacyjne obejmowały: docieplenie przegród zewnętrznych styropianem grafitowym o współczynniku przewodzenia ciepła λ = 0,30 W/(m·K) i grubości warstwy 20 cm, wymianę kotła węglowego na kocioł gazowy dwufunkcyjny z podgrzewaczem ciepłej wody użytkowej, wymianę grzejników żeliwnych na grzejniki trójpłytowe stalowe oraz grzejnik drabinkowy w łazience, wymianę okien drewnianych dwuszybowych o współczynniku przenikania ciepła Uw = 2,60 W/(m²·K) na okna drewniano-aluminiowe o współczynniku przenikania ciepła Uw = 0,95 W/(m²·K) z dwukomorowym pakietem szyb.

6

Experimental study of dispersed flow in the thermopressor of the intercooling system for marine and stationary power plants compressors

Konovalov Dmytro, Kobalava Halina, Radchenko Mykola, Løvås Terese, Pavlenko Anatoliy, Radchenko Roman, Radchenko Andrii

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2024

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Vol. 72, nr 1

art. no. e148439

EN

This study investigates the use of a thermopressor to achieve highly dispersed liquid atomization, with a primary focus on its application in enhancing contact cooling systems of the cyclic air for gas turbines. The use of a thermopressor results in a substantial reduction in the average droplet diameter, specifically to less than 25 μm, within the dispersed flow. Due to practically instantaneous evaporation of highly atomized liquid droplets in accelerated superheated air the pressure drop is reduced to minimum. A further increase of the air pressure takes place in diffuser. In its turn, this allows for the compensation of hydraulic pressure losses in the air path, thereby reducing compressive work. Experimental data uncover a significant decrease in the average droplet diameter, with reductions ranging from 20 to 30 µm within the thermopressor due to increased flow turbulence and intense evaporation. The minimum achievable droplet diameter is as low as 15 µm and accompanied by a notable increase in the fraction of small droplets (less than 25 µm) to 40–60%. Furthermore, the droplet distribution becomes more uniform, with the absence of large droplets exceeding 70 µm in diameter. Increasing the water flow during injection has a positive impact on the number of smaller droplets, particularly those around 25 μm, which is advantageous for contact cooling. The use of the thermopressor method for cooling cyclic air provides maximum protection to blade surfaces against drop-impact erosion, primarily due to the larger number of droplets with diameters below 25 μm. These findings underline the potential of a properly configured thermopressor to improve the efficiency of contact cooling systems in gas turbines, resulting in improved performance and reliability in power generation applications. The hydrodynamic principles explored in this study may have wide applications in marine and stationary power plants based on gas and steam turbines, gas and internal combustion engines.

7

Advanced fuel system with gaseous hydrogen additives

Shalapko Denys, Radchenko Mykola, Pavlenko Anatoliy, Radchenko Roman, Radchenko Andrii, Pyrysunko Maxim

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2024

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Vol. 72, nr 2

art. no. e148837

EN

The advancement of contemporary internal combustion engine technologies necessitates not only design enhancements but also the exploration of alternative fuels or fuel catalysts. These endeavors are integral to curbing the emission of hazardous substances in exhaust gases. Most contemporary catalyst additives are of complex chemical origins, introduced into the fuel during the fuel preparation stage. Nonetheless, none of these additives yield a significant reduction in fuel consumption. The research endeavors to develop the fuel system of a primary marine diesel engine to facilitate the incorporation of pure hydrogen additives into diesel fuel. Notably, this study introduces a pioneering approach, employing compressed gaseous hydrogen up to 5 MPa as an additive to the principal diesel fuel. This method obviates the need for extensive modifications to the ship engine fuel equipment and is adaptable to modern marine power plants. With the introduction of modest quantities of hydrogen into the primary fuel, observable shifts in the behavior of the fuel equipment become apparent, aligning with the calculations outlined in the methodology. The innovative outcomes of the experimental study affirm that the mass consumption of hydrogen is contingent upon the hydrogen supply pressure, the settings of the fuel equipment, and the structural attributes of the fuel delivery system. The modulation of engine load exerts a particularly pronounced influence on the mass admixture of hydrogen. The proportion of mass addition of hydrogen in relation to the pressure of supply (ranging from 4–12 MPa) adheres to a geometric progression (within the range of 0.04–0.1%). The application of this technology allows for a reduction in the specific fuel consumption of the engine by 2–5%, contingent upon the type of fuel system in use, and concurrently permits an augmentation in engine power by up to 5%. The resultant economic benefits are estimated at 1.5–4.2% of the total fuel expenses. This technology is applicable across marine, automotive, tractor, and stationary diesel engines. Its implementation necessitates no intricate modifications to the engine design, and its utilization demands no specialized skills. It is worth noting that, in addition to hydrogen, other combustible gases can be employed.

8

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.

9

Heat Transfer Characteristics of a Combination of Two Double-chamber Windows

Basok Borys, Davydenko Borys, Pavlenko Anatoliy, Novikov Volodymyr, Goncharuk Svitlana

Rocznik Ochrona Środowiska

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2023

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Tom 25

289--300

EN

Low-emissivity coatings on glass surfaces, inert gas instead of air between glasses, and double-glazed windows are usually used to reduce heat loss from a room through windows. This effect can also be achieved by installing two double-chamber windows in one window opening at a certain distance from each other. This work uses numerical modelling to study the characteristics of heat transfer through a system of two two-chamber windows. The distributions of temperature and airflow velocity due to natural convection in the chambers of double-chamber windows and the space between the windows are analyzed. The distributions of temperatures and heat fluxes over the surfaces of windows are determined depending on the distance between the windows. The dependences on the distance between the windows of radiation, convective, and total heat flow through a system of two double-chamber windows are studied. It is shown that two double-chamber windows located at a certain distance from each other make it possible to increase the heat transfer resistance compared to one two-chamber window without a low-emission coating by 2.6...2.8 times. As the distance between windows increases, a given system's overall heat transfer resistance increases. However, this increase becomes insignificant if this distance is greater than 80 mm.

10

A Two-dimensional Numerical Model of Heat Exchange in the Soil Massif During the Operation of a Shallow Horizontal Soil Heat Exchanger

Basok Boris, Pavlenko Anatoliy, Nedbailo Oleksandr, Bozhko Ihor, Moroz Maryna

Rocznik Ochrona Środowiska

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2023

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Tom 25

274--281

EN

The current article uses a two-dimensional numerical model to represent the results of theoretical studies of the heat exchange in the soil massif during the operation of a shallow horizontal soil heat exchanger. The analysis of literature sources showed that one of the important conditions for the effective operation of a shallow-soil heat exchange is its rational design parameters, such as the total length of the pipeline, the diameter of the pipe, the distance between the axis of the adjacent pipes, the depth of the heat exchanger placement, etc. A two-dimensional heat exchange model in the soil mass was developed, which made it possible to investigate the operation of a shallow horizontal soil heat exchanger. It was found that the step between the axis of the adjacent pipes of the multi-loop heat exchanger, which is 0.95 m, is optimal when creating a shallow horizontal soil heat exchanger in the soil conditions of Kyiv.

11

Wpływ bariery termicznej na efektywność energetyczną zestawu szybowego

Pavlenko Anatoliy, Piotrowski Jerzy Zbigniew, Stępień Anna, Ciosek Anita, Sadko Karolina

Materiały Budowlane

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2023

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nr 9

54--57

PL

Mimo postępu technologicznego okno i najważniejszy jego składnik - zestaw szybowy to najsłabsze ogniwo izolacyjne przegrody budynku. W Politechnice Świętokrzyskiej rozpoczęto badania nad poprawą izolacyjności zestawów szybowych przez zastosowanie elementów grzewczych w komorze wewnętrznej międzyszybowej, tworząc tzw. barierę termiczną. Przedmiotem artykułu jest pokazanie możliwości podwyższenia temperatury zestawu, przeprowadzenie analizy numerycznej i eksperymentalnej, ocena bilansu energetycznego, przy założeniu, że bariera termiczna zasilana zostanie energią odnawialną.

EN

Despite technological progress, the window and its most important component - double glazing - is the weakest insulating link of the entire building envelope. At the Technology University of Kielce, research has begun on improving the insulation of double glazing through the use of heating elements in the inner chamber between the panes, creating the so-called thermal barrier. The focus of the article is to show the possibility of increasing the temperature of the glazing unit, to carry out numerical and experimental analysis, to assess the energy balance, assuming that the thermal barrier will be powered by renewable energy.

12

Analysis of the Energy Efficiency of the Earth-To-Air Heat Exchanger

Basok Boris, Pavlenko Anatoliy, Nedbailo Aleksandr, Bozhko Ihor, Novitska Maryna, Koshlak Hanna, Tkachenko Myroslav

Rocznik Ochrona Środowiska

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2022

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Tom 24

202--213

EN

This article represents the results of experimental studies of the temperature regime during the long-term operation of the earth-to-air heat exchanger. The average annual, total monthly and daily average specific amounts of heat extracted from the soil or released into the soil mass, respectively, depending on the cold or warm periods of the year, were determined. Analyzing the given data allowed a monthly assessment of the energy efficiency of using the earth-to-air heat exchanger. It is noted that the most significant thermal contribution occurs in the middle of the warm and cold periods of the year when the most significant difference in temperature of the outside air and the soil massif is observed. The use of earth-to-air heat exchangers is one of the necessary tools to lower the energy consumption for modern air-conditioning systems of buildings due to their energy efficiency.

13

Self-preservation Effect of Gas Hydrates

Pavlenko Anatoliy

Rocznik Ochrona Środowiska

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2021

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Tom 23

346--355

EN

This work was performed to improve the storage and transportation technology of gas hydrates in nonequilibrium conditions. At atmospheric pressure and positive ambient temperature, they gradually dissociate into gas and water. Simulation of the gas hydrate dissociation will determine optimal conditions for their transportation and storage, as well as minimize gas loss. Thermodynamic parameters of adiabatic processes of forced preservation of pre-cooled gas hydrate blocks with ice layer were determined theoretically and experimentally. Physical and mathematical models of these processes were proposed. The scientific novelty is in establishing quantitative characteristics that describe the gas hydrates thermophysical parameters thermophysical characteristics influence on the heat transfer processes intensity on the interphase surface under conditions of gas hydrates dissociation. Based on the results of experimental studies, approximation dependences for determining the temperature in the depths of a dissociating gas hydrate array have been obtained. Gas hydrates dissociation mathematical model is presented.

14

Municipal Heat Energy of Ukraine - Adaptation to Global Warming

Basok Borys, Bazeev Evgeny, Pavlenko Anatoliy, Kurayeva Iryna

Rocznik Ochrona Środowiska

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2021

|

Tom 23

552--568

EN

Rising global temperatures have exacerbated the problems of adaptation to climate change in various sectors of the economy, including municipal energy. Therefore, the task is to develop measures and mechanisms, the implementation of which will guarantee cost-effective comfortable and reliable heat and cold supply of buildings and structures in climate change. Experimental studies of heat transfer and monitoring of thermal regimes in enclosing structures and building elements were conducted with the development of innovative engineering systems for energy supply of a passive house of the "zero-energy" type. Experimental developments of innovative energy-efficient greenhouse gas-reducing technologies and equipment for energy supply systems of buildings have been performed and their architectural and construction solutions for adaptation to climate change have been optimized. In order to expand and deepen the theory and practice of improving the energy efficiency of buildings in the near future, the scientific priority and subject of basic and applied research have been identified. Developed adaptive to climate change innovative, energy efficient technologies and equipment of engineering systems of energy supply of buildings with the use of renewable energy sources can be used in the practice of energy supply of housing and communal services.

15

The influence of geometric characteristics of the buildings facades on the heat transfer to the wind flow

Basok Boris, Davydenko Boris, Pavlenko Anatoliy, Novikov Vladimir, Novitska Marina

Journal of New Technologies in Environmental Science

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2021

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Vol. 5, nr 1

11--22

EN

This paper presents the results of a numerical study of heat transfer from the external surfaces of freestanding structures in the surface layer of the atmosphere. Numerical models of structures have the same heat transfer area, but different heights and lengths. Numerical modeling of heat transfer from structures in a wind flow in a three-dimensional formulation made it possible to establish some features of convective heat transfer from enclosing structures, depending on the height of the building and the speed of the wind flow. In particular, it is shown that the dependence of the surface-averaged values of the heat flux density on the height of the building has a local minimum, after which the average heat flux density increases insignificantly with an increase in the height of the building.

16

Generation of pressure oscillations in air flows in vertical channels with internal heat release

Basok Boris, Davydenko Boris, Pavlenko Anatoliy

Journal of New Technologies in Environmental Science

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2021

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Vol. 5, nr 3

106--116

EN

The characteristics of the air flow in a vertical channel, arising due to local internal heat release, are investigated by the method of numerical simulation. Heat is supplied to the flow from internal sources located in a limited volume closer to the inlet section of the channel. The problem of flow and heat transfer is described by a system of unsteady Navier-Stokes and energy equations for a compressible medium. The coefficients of viscosity and thermal conductivity are considered to be temperature dependent. From the numerical solution of this system, the velocity, pressure, and temperature fields in the channel are determined. Based on the results of the calculations, the regularities of the change in time of velocity and pressure in the channel are determined. From the analysis of the results it follows that from the moment the heat supply begins, a vertical air flow develops in the channel, which is accompanied by oscillations in velocity and pressure. Self-oscillations arising in a gas flow are a manifestation of instability of flow. It is shown that stable oscillations take place in the presence of additional local hydraulic resistance in the channel. The dependence of the amplitude and frequency of pressure oscillations and the air flow velocity on the power of the sources of internal heat release and the height of the channel has been investigated. It was determined that with an increase in the power of the source of internal heat supply and the height of the channel, the amplitudes of the velocity and pressure fluctuations increase.

17

Thermophysical-based Effect of Gas Hydrates Self-Preservation

Kutnyi Bohdan, Pavlenko Anatoliy, Koshlak Hanna

Rocznik Ochrona Środowiska

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2020

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Tom 22, cz. 1

11--23

EN

To improve gas hydrates dissociation technology, studies of heat transfer processes on the interfacial surface are significant. In the work, experimental and theoretical studies of the gas hydrates dissociation are presented. The scientific novelty is in establishing quantitative characteristics that describe the gas hydrates thermophysical parameters thermophysical characteristics influence on the heat transfer processes intensity on the interphase surface under conditions of gas hydrates dissociation. Based on the results of experimental studies, approximation dependences for determining the temperature in the depths of a dissociating gas hydrate array have been obtained. Gas hydrates dissociation mathematical model is presented. The practical significance of the research results is in determining quantitative indicators of the heat transfer processes intensity under the conditions of propane hydrate dissociation. The results of the work can be applied to designing equipment for gas hydrates storage and dissociation.

PL

Badania procesów wymiany ciepła na powierzchni międzyfazowej mają ogromne znaczenie dla poprawy technologii dysocjacji hydratów gazowych. W pracy przedstawiono eksperymentalne i teoretyczne badania dysocjacji hydratów gazu. Nowość polega na ustaleniu cech ilościowych, które opisują wpływ właściwości termofizycznych hydratów gazu na intensywność procesów wymiany ciepła na powierzchni międzyfazowej w warunkach dysocjacji hydratów gazu. Na podstawie wyników badań eksperymentalnych uzyskuje się zależności aproksymacyjne do określania temperatury na głębokościach dysocjującego układu hydratów gazu. Przedstawiono matematyczny model dysocjacji hydratów gazu. Praktyczne znaczenie wyników badań polega na określeniu ilościowych wskaźników intensywności procesów wymiany ciepła w warunkach dysocjacji hydratu propanu. Wyniki można zastosować w projektowaniu urządzeń do magazynowania i dysocjacji hydratów gazu.

18

Presentation of Experimental Biomass Gasification with Minimizing Gibbs Free Energy Mathematical Model

Pavlenko Anatoliy, Slowak Anna Maria

Rocznik Ochrona Środowiska

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2020

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Tom 22, cz. 2

880--891

EN

The paper consists the results from the conducted experiment and the mathematical model of it. The presented process is biomass gasification and the modelling is based on complex parameter that is maximum thermodynamic efficiency and use the Gibbs free energy function and Lagrange multiplier. Referring to European Union strategy in terms of energy use it is highly recommended to increase the share of renewable energy in total energy production. The biomass is one of the most important sources of energy. Listed above methods of mathematical calculations let as define the composition of the gas produced and the efficiency that was reached. Also the precision of the model was evaluated. The effect of the work done is the possibility to use it to state the best condition for the process of biomass gasification technology.

PL

Artykuł przedstawia wyniki przeprowadzonego eksperymentu i jego model matematyczny. Przedstawiony proces dotyczy zgazowania biomasy, a modelowanie opiera się na złożonym parametrze, jakim jest maksymalna wydajność termodynamiczna, z wykorzystaniem funkcji energii swobodnej Gibbsa i mnożnika Lagrange'a. Nawiązując do strategii Unii Europejskiej w zakresie zużycia energii, zdecydowanie zaleca się zwiększenie udziału energii odnawialnej w całkowitej produkcji energii. Biomasa jest jednym z najważniejszych źródeł energii. Wymienione powyżej metody obliczeń matematycznych pozwalają określić skład wytwarzanego gazu i osiągniętą wydajność. Oceniono także precyzję modelu. Efektem wykonanych prac jest możliwość określenia najlepszych warunków prowadzenia procesu technologii zgazowania biomasy.

19

Mathematical Model of the Drying Process of Wet Materials

Pavlenko Anatoliy, Piotrowski Jerzy Zbigniew

Rocznik Ochrona Środowiska

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2020

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Tom 22, cz. 1

347--358

EN

The problem of heat treatment of wet materials contains the question of the heat and mass inside the body transfer (an internal problem) and in the boundary layer at the interface between phases (an external problem). The amount of removable moisture depends on the degree of each of these processes development. When heated, the moisture content on the surface decreases, creating a concentration difference across the body. Therefore, a flow of moisture occurs in the body from deep layers to the surface, towards which the flow of heat is directed. Thus, when wet materials are heated, complex processes of moisture and heat exchange occur, mutually affecting the enthalpy and moisture content of both the heated material and the environment. The features of mathematical model construction of heating and drying of wet materials process are considered in the article. The drying process is defined as a thermal process with effective heat transfer coefficients with consideration of mass transfer. It makes it possible to obtain analytical dependencies that are convenient for engineering calculations, with which you can determine the temperature field and evaluate the kinetics of wet materials drying.

PL

Problem obróbki cieplnej wilgotnych materiałów obejmuje zagadnienia transferu ciepła i masy wewnątrz komponentu (problem wewnętrzny) i w warstwie granicznej z przemianą fazową (problem zewnętrzny). Ilość usuwanej wilgoci zależy od stopnia rozwoju każdego z tych procesów. Po podgrzaniu zawartość wilgoci na powierzchni zmniejsza się, tworząc różnicę koncentracji w całym materiale. Dlatego w materiale występuje przepływ wilgoci z głębokich warstw na powierzchnię, na którą skierowany jest przepływ ciepła. Oznacza to, że gdy ogrzewane są wilgotne materiały, zachodzą złożone procesy wymiany wilgoci i ciepła, wpływając wzajemnie na entalpię i zawartość wilgoci zarówno ogrzewanego materiału, jak i środowiska.W artykule omówiono cechy budowy modelu matematycznego procesu ogrzewania i suszenia materiałów zawilgoconych. Proces suszenia definiuje się jako proces termiczny o efektywnych współczynnikach przenikania ciepła z uwzględnieniem transferu masy. Umożliwia uzyskanie zależności analitycznych dogodnych do obliczeń inżynierskich, za pomocą których można określić pole temperatury i ocenić kinetykę suszenia wilgotnych materiałów.

20

Mathematical Model of Particle Free Settling in a Vortex Apparatus

Koshlak Hanna, Pavlenko Anatoliy

Rocznik Ochrona Środowiska

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2020

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Tom 22, cz. 2

727--734

EN

A mathematical model of gas dynamics in a vortex apparatus during heat treatment is presented in the paper. The parameters of gas flows in the vortex apparatus, optimal ratios of the vortex apparatus geometric dimensions, as well as hydrodynamic parameters are determined, making it possible to develop effective design solutions of this equipment. The mathematical model allows one to carry out computational experiments and determine particle trajectories, their temperature, particle size and humidity at various points in time and evaluate the dynamics of these parameters. Using the calculation experiment method makes it possible to quickly and without financial costs determine the technological modes of heat treatment of dispersed material in vortex devices. The obtained data can be used in calculation methods of heat and mass transfer vortex apparatuses.

PL

W artykule przedstawiono matematyczny model dynamiki gazu w aparacie wirowym podczas obróbki cieplnej zdyspergowanych materiałów. Określane są parametry przepływów gazu w aparacie wirowym, identyfikowane są optymalne proporcje wymiarów geometrycznych aparatu wirowego, a także parametry hydrodynamiczne, które pozwalają opracowywać skuteczne rozwiązania konstrukcyjne tego sprzętu. Model matematyczny umożliwia przeprowadzanie eksperymentów obliczeniowych i określanie trajektorii cząstek, ich temperatury, wielkości cząstek i wilgotności w różnych punktach czasowych oraz ocenić dynamikę zmian tych parametrów. Zastosowanie metody eksperymentu obliczeniowego pozwala szybko i bez kosztów finansowych określić warunki technologiczne do obróbki termicznej rozproszonego materiału w urządzeniach wirowych o różnych konstrukcjach. Uzyskane dane można wykorzystać w metodach obliczania urządzeń wirowych z wymianą ciepła i masy.