Volumes III.    Number  1    March 2020    Year 2020
Authors Title Pages
René Atyafi, Augustín Varga, Gustáv Jablonský, Róbert Dzurňák Comparison of Convection Models for Hot Blast Stove Regenerative Chamber 01-05
Miroslav Káňa, Peter Oravec Phase change materials for energy storage: A review 06-13
Kristína Petrušková, Erika Liptáková Development of electricity prices in the V4 countries and econometric model of forecasting spot electricity prices in Slovakia 14-24
Przemysław Rajca, Monika Zajemska, Magdalena Skrzyniarz, Piotr Pietruszka, Tomasz Kłosiński, Joanna Olawińska-Wypych Thermal Treatment of Municipal Waste in Poland on Example of RDF Pyrolysis 25-33

Pages 01-05

Title:

Comparison of Convection Models for Hot Blast Stove Regenerative Chamber

Authors:

René Atyafi, Augustín Varga, Gustáv Jablonský, Róbert Dzurňák

Abstract:

Low error numerical solutions of convective heat transfer in high-temperature air regenerative heat exchangers in the convective regime rely on the correct determination of the wall heat transfer coefficient. Presented are results of simulations computed using a similarity theory-based numerical model. They imply that the current empirical formulas based on the theory of similarity, derived for analogous model cases of convective heat transfer do not allow to achieve satisfactory accuracy. Actual dependencies of parameters and criteria yielding more representative heat transfer coefficient values might be obtained through the means of experimental research in thermodynamics of an experimental device.

Citation:

Atyafi René, Varga Augustín, Jablonský Gustáv, Dzurňák Róbert: Comparison of Convection Models for Hot Blast Stove Regenerative Chamber, Advance in Thermal Processes and Energy Transformation, Volume 3, No.1 (2020), p. 01-05, ISSN 2585-9102

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Pages 06-13

Title:

Phase change materials for energy storage: A review

Authors:

Miroslav Káňa, Peter Oravec

Abstract:

Phase change materials are one of the most suitable materials to effectively utilize the thermal energy from renewable energy. This review is based on the thermophysical properties of various phase change materials. In particular, the melting point, thermal energy storage density and thermal conductivity of organic, inorganic and eutectic phase change materials are the main selection criteria for various thermal energy storage applications over a wide operating temperature range.

Citation:

Káňa Miroslav, Oravec Peter: Phase change materials for energy storage: A review, Advance in Thermal Processes and Energy Transformation Volume 3, No.1, (2020), p. 06-13, ISSN 2585-9102

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Pages 14-24

Title:

Development of electricity prices in the V4 countries and econometric model of forecasting spot electricity prices in Slovakia

Authors:

Kristína Petrušková, Erika Liptáková

Abstract:

In this article, the authors focused on the development of electricity prices on wholesale and retail markets in the Visegrad Four countries (V4). The main goal of the paper is to design an econometric model of predicting spot electricity prices in Slovakia. Therefore, the model of multiple linear regression is used, based on knowledge from the literature and existing studies. The model can be used to predict the possible development of electricity prices depending on several relevant variables - coal prices, gas prices and the share of renewable energy sources. The data were obtained from Eurostat and OECD databases, investment sites, which showed the development of commodity prices on wholesale market, or from power exchanges or a short-term electricity market operator. RStudio software was then used to evaluate created models. The result was price forecasts for further periods, which were also compared with the actual spot prices.

Citation:

Petrušková Kristína, Liptáková Erika: Development of electricity prices in the V4 countries and econometric model of forecasting spot electricity prices in Slovakia, Advance in Thermal Processes and Energy Transformation, Volume 3, No.1 (2020), p. 14-24, ISSN 2585-9102

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Pages 25-33

Title:

Thermal Treatment of Municipal Waste in Poland on Example of RDF Pyrolysis

Authors:

Przemysław Rajca, Monika Zajemska, Magdalena Skrzyniarz, Piotr Pietruszka, Tomasz Kłosiński, Joanna Olawińska-Wypych

Abstract:

In the face of the constant tightening of environmental regulations, alternative sources of fuels and energy are being increasingly sought. The European Union strives to introduce waste-free or low-waste closed-loop technologies using material and energy recovery to manage natural resources in a rational manner. Therefore, European regulations require member states to progressively restrict the amount of landfill waste. In Poland, these requirements have been included in the Act on waste and the Act on order and cleanliness in the commune. In addition, since 1 January 2016, it has been forbidden to store waste with a calorific value exceeding 6 MJ/kg, which is why in recent years there has been an increase in interest in the thermal transformation of municipal waste. Therefore, the article presents the current shape of waste management in Poland, and also introduces the dominant form of RDF management in the cement industry. Nevertheless, the capacity of cement plants is limited, and the energy use of fuels from waste encounters difficulties related to a significant reduction in pollutant emissions, which is why the use of modern installations for the thermal conversion of waste such as pyrolysis and gasification is increasingly considered. Taking into account the promising energy properties of secondary fuels obtained during the pyrolysis process, the chemical composition of gas from RDF pyrolysis was modeled for a pilot installation operating in Poland using CHEMKIN-PRO software. Determination of the combustible components allowed the calorific value of pyrolytic gas to be estimated, ranging from 28.2 - 28.7 MJ/m3. The obtained calorific value is much higher than the average calorific value of RDF (11-18MJ/kg) [1], which encourages wider use of the waste pyrolysis process in order to obtain secondary fuels with promising energy parameters. It will contribute to a further reduction in the amount of deposited waste, and thus to creating environmentally-friendly closed-loop waste management.

Citation:

Rajca Przemysław, Zajemska Monika, Skrzyniarz Magdalena, Pietruszka Piotr, Kłosiński Tomasz, Olawińska-Wypych Joanna: Thermal Treatment of Municipal Waste in Poland on Example of RDF Pyrolysis, Advance in Thermal Processes and Energy Transformation, Volume 3, No 1 (2020), p. 25-33, ISSN 2585-9102.

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