
Janusz SkorekSilesian University of Technology
Janusz Skorek
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44
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Introduction
Publications
Publications (44)
New temperature limits analytical model of the Ranque–Hilsch vortex tube has been proposed within the presented paper. The model originates from the local compression/expansion and inner friction hypothesis anticipated to be responsible for the Ranque–Hilsch effect. The model in a presented form provides a fair estimation of the temperature limits...
One of the possible solution for conventional coal-fired heat sources of district heating systems is repowering with a cogeneration of heat and power) unit. Thermal and economic optimization of the such modernization is the subject of the paper. The total capacity of the existing heat generating plant reaches 210 MW and the generated heat is delive...
District heating technologies should be efficient, effective and environmentally friendly. The majority of the communal heating systems in Poland produce district hot water in coal-fired boilers. A large number of them are considerably worn out, low-efficient in the summer time and will not comply with forthcoming regulations. One of the possible s...
The paper presents basic circumstances of installation gas supplied microcogeneration systems μCHP in buildings. Microcogeneration system based on IC engines and microturbines of nominal electric power from 20 kW up to 1 MW are considered. Specific features of heat and electricity demand in buildings are discussed. Exploitation aspects of uCHP sizi...
The paper discusses chosen issues concerning damaged gas pipelines. Attention is paid to modelling the steady-state flow of natural gas in distribution pipelines, and the most commonly applied models of isothermal and adiabatic flow are evaluated for both the ideal and the real gas properties. A method of accounting for a leakage by means of a refe...
The paper explores possibilities of applying the IR thermography for integrity evaluation and quick detection of failures in natural gas delivery stations. The natural gas stations typically comprise overground facilities for filtering, pressure reduction, flow metering and odorizing. The facilities and the interconnecting pipelines are subject to...
The paper presents the assumptions and the architecture of a multi-layer system for a perimetric protection of an industrial infrastructure object, i.e. the natural gas city gas station. Perimetry, which originally refers to the systematic measurement of human's eye visual system, here is used to describe system capabilities of monitoring a wide-an...
Identification of thermal resistance of the gas-gap between the ingot and mould, as well as the heat flux distribution on the phase change from the solid side during continuous casting of metals is the subject of this article. Analysed parameter estimation problems of the steady-state heat conduction belong to the group of inverse problems. The pre...
Aspects of using the small‐scale combined heat and power modules in buildings is presented in this paper. At first the problems of energy demand analysis, which is the key point of a co‐generation plant sizing procedure, are discused. Then the demonstration project of a small‐scale co‐generation plant is presented. The plant is fuelled with natural...
Aspects of using the small-scale combined heat and power modules in buildings is presented in this paper. At first the problems of energy demand analysis, which is the key point of a co-generation plant sizing procedure, are discused. Then the demonstration project of a small-scale co-generation plant is presented. The plant is fuelled with natural...
The method for combining the numerical gas network simulation with experimentally determined flow characteristics of pipeline ruptures is presented which enables calculation of gas losses from damaged gas networks. Main causes of damages are discussed and the thermodynamics of gas flow through pipelines, nozzles and irregular openings as well as pr...
The thermodynamic analysis of the compressed-air energy storage system (CAES system) is presented. Two types of CAES systems, with respect to the underground reservoir operation, are considered: variable- and constant-pressure ones. Several configurations of the CAES system are analysed. Influence of the main thermal parameters (pressure of the sto...
The problem of appropriate location of the sensors for identification of ingot – mould thermal resistance during continuous casting of metals is the subject of the paper. Analysed problem belongs to the group of inverse problems. The present work shows also the method of identification of unknown thermal resistance using the temperature measurement...
The possibility of improvement of the energy performance and economic feasibility of a CHP plant by the use of hot water storage tank is analysed in the paper. An energy balance of a system consisting of a CHP module, a peak boiler and a heat storage unit has been built and the storage efficiency has been defined. Heat transfer in storage tanks and...
Energetic and economic optimization of the modernization of municipal heating plants by installation of CHP (Combined Heat and Power) unit with gas turbine and heat recovery boiler is analyzed. The problem of technical and economical optimization of the modernization of heating plants by installing the CHP system with gas a turbine is discussed and...
Identification of thermal resistance of the gas-gap between the ingot and mould during continuous casting of metals is the subject of the present article. Analysed parameter estimation problem of the steady-state heat conduction belongs to the group of inverse problems. The present work shows the possibility of applying the least square adjustment...
The identification of thermal resistance of the gas-gap between the ingot and mould during continuous casting of metals is the subject of presented paper. Analysed parameter estimation problem of the steady-state heat conduction belongs to the group of inverse problems. Presented work shows the possibility of applying of the least square adjustment...
This chapter presents the identification of thermal resistance of the gas gap between the ingot and mould during continuous casting of metals. Analyzed parameter estimation problem of the steady-state heat conduction belongs to the group of inverse problems. It shows the possibility of applying of the least square adjustment method with a priori da...
Different parameters of fuel atomization can influence the intensity of thermal radiation of the liquid fuel flame. Investigations which were carried out by the authors proved that the fuel consumption required for heating up the charge in the furnace can be reduced when using appropriate atomization of the fuel. That effect depends mainly on the t...
p>The influence of an open system blade cooling on the efficiency of the humid air turbine has been analyzed. It has been assumed that three stages of the turbine are cooled by means of compressed air taken from the outlet of the compressor. The thermodynamic analysis showed, that the deleterious impact of blade cooling results mainly from the irre...
The combined theoretical and experimental method for simultaneous determination of thermal properties (thermal conductivity λ and dyfussivity a) of different solid bodies has been presented in this paper. The mathematical model of the considered problem has been formulated. Using the control volume method the equations of the model have been transf...
The operation of the non-throttling Granryd refrigerator has been analysed. The experimental installation is presented. The measurement method and obtained results are presented and discussed. The mathematical model of the process was also built to analyse the influence of several design and operation parameters on the efficiency of the refrigerato...
This work discusses the solution of two-dimensional inverse heat conduction problems by a derivative method. The solution is presented in terms of temperature data and their time derivatives. A Gram orthogonal polynomial method is proposed for smoothing noisy data spatially and along the time and to approximate the time derivatives of temperature d...
This paper examines the accuracy of a space marching formulation for solving two-dimensional inverse heat conduction problems. The parameters that have a major influence on the solution such as time step size, measurement errors and Biot number are investigated. The temperature and heat flux on the surface of a body are estimated on the base of the...
The study of the parameter estimation problems using a two-dimensional numerical model is presented in this paper. The solution procedure uses temperature data from measurement points (sensors). The solution starts assuming arbitrary values of thermal diffusivity. Then, a finite element method is employed for numerical calculations. The next step i...
In general the elements of electronic equipment, i.e. module plates together with semiconductor devices and external chassis create regular rectangular ducts, so called module ducts. During the operation of the electronics equipment the heat is generated in the semiconductor devices. That heat is transferred to the cooling agent which flows along t...
A Kalman filter method in conjunction with the nonuniform control volume methodology is adopted as a numerical tool for solving two-dimensional inverse heat conduction problems for a moving body. This work focuses on estimation of the transient temperature in the solid region of the workpiece during welding process that involves a moving heat sourc...
Identification of thermal resistance between cast and mould during permanent casting of metals is the subject of present paper. Mathematically, analyzed boundary problem of heat conduction belongs to the group of inverse problems. Inverse problems belong to the class of ill posed problems. It means, that solution of the problem is usually extremely...
Efficiency of the combustion process is determined by the intensity of the heat transfer between the flame and heated up objects. The results of investigations of the combustion of the liquid fuel (oil) which is atomized in the twin-fluid atomizer are analyzed in the paper. Essential object of the research was the estimation of the influence of the...
A mathematical model of the ingot temperature field in the continuous casting of copper and other pure metals is presented. The finite-difference method is applied and the difference equations are derived by the elementary energy balances method. An axially symmetrical two-dimensional temperature field in the cast metal and the die is considered. T...
Streszczenie. W pracy przeprowadzono analizę techniczną i wstępną analizę ekonomiczną modernizacji węglowego bloku energetycznego o mocy 50 MW poprzez nadbudowę turbozespołem gazowym lub spalinowym silnikiem gazowym. Założono, że w wyniku nadbudowy nie zostaną w sposób istotny zmienione parametry i konstrukcja urządzeń części parowej bloku energety...
Streszczenie. W pracy przedstawiono przesłanki zastosowania akumulacji ciepła w układach kogeneracyjnych w oparciu o różne tryby pracy tych układów. W małych układach kogeneracyjnych funkcję zasobników najczęściej pełnią wyporowe zasobniki gorącej wody. Przedstawiono sposób współpracy zasobnika z układem skojarzonym oraz bilans energii procesu akum...
Ostatnie lata rozwoju energetyki krajowej to okres intensyw- nego wzrostu zainteresowania odnawialnymi źródłami energii. Liczne analizy pokazują, że najważniejszym źródłem energii odnawialnej w Polsce jest biomasa. W najbliższych latach spo- dziewany jest znaczny wzrost jej udziału w krajowej strukturze zużycia paliw pierwotnych. Biomasa to wszelki...
Streszczenie. W pracy przedstawiono wyniki analizy potencja³u rynku polskiego w zakresie mo¿liwoœci zastosowania paliw gazowych do rozproszonego wytwarzania energii elektrycznej i ciep³a w technolo- gii skojarzonej. Omówiono g³ówne obszary zastosowañ gazowych uk³adów kogeneracyjnych i dla wiêkszoœci z nich przedstawiono czynni- ki warunkuj¹ce powod...
Streszczenie: W pracy zaproponowano metode optymalizacji doboru urzadzen i konfiguracji ukladów skojarzonych energetyki rozproszonej. Przedstawiona metoda bazuje na kryterium ekonomicznym. Zbudowano model matematyczny oraz omówiono glówne problemy zwiazane z rozwiazaniem zadnia. Przedstawiono takze wyniki przykladowych obliczen.
Methodology and computer code for simulations and optimisation of the small-scale CHP plants are presented in the paper. Detailed heat and electricity demand profiles of the site are applied for analysing technical and economical effects of the plant operation and optimisation of the system. The maximum of the Net Present Value (NPV) is selected as...