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Experience of using ŁPrP, ŁPKO, ŁPSp, ŁPSpA i ŁPSp3R flattened supports in the conditions of Knurów-Szczygłowice coal mine

Piotr Głuch Grzegorz Michalik Tomasz Śledź Piotr Kleibert Adam Ratajczak Jarosław Sobik
Zeszyty Naukowe Instytutu Gospodarki Surowcami Mineralnymi Polskiej Akademii Nauk | 2017 | Nr 99 | 89-108
Keywords exploitation supports selection of supports for longwall’s set-up rooms
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Abstract

The paper presents the experience of using the ŁPrP, ŁPKO, ŁPSp, ŁPSpA i ŁPSp3R types of flattened supports for longwall entries in the conditions of the JSW S.A. Knurów-Szczygłowice coal mine. The article concentrates on the support solutions applied in the conditions of the mine and the results in terms of stability and usefulness of the structures of the supports. An analysis of the load bearing capacity and technological conditions has been conducted for various flattened supports solutions, with special consideration given to the ŁPSp and ŁPrPJ support sets. Comparing these two, the ŁPSp exhibits a load bearing capacity that is 21% higher while using 31% less steel mass. The experiment results allowed to determine that the ŁPSpA and ŁPSp3R support types are an advantageous solutions in case of longwall set-up rooms.

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Authors and Affiliations

Piotr Głuch
Grzegorz Michalik
Tomasz Śledź
Piotr Kleibert
Adam Ratajczak
Jarosław Sobik

Experimental and theoretical study of dryout in annular flow in small diameter channels

Jan Wajs Dariusz Mikielewicz Michał Gliński
Archives of Thermodynamics | 2011 | No 1 April | 89-108 | DOI: 10.2478/v10173-011-0005-5
Keywords Dryout flow boiling CHF Annular flow
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Abstract

In the paper the experimental analysis of dryout in small diameter channels is presented. The investigations were carried out in vertical pipes of internal diameter equal to 1.15 mm and 2.3 mm. Low-boiling point fluids such as SES36 and R123 were examined. The modern experimental techniques were applied to record liquid film dryout on the wall, among the others the infrared camera. On the basis of experimental data an empirical correlation for predictions of critical heat flux was proposed. It shows a good agreement with experimental data within the error band of 30%. Additionally, a unique approach to liquid film dryout modeling in annular flow was presented. It led to the development of the three-equation model based on consideration of liquid mass balance in the film, a two-phase mixture in the core and gas. The results of experimental validation of the model exhibit improvement in comparison to other models from literature.

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Authors and Affiliations

Jan Wajs
Dariusz Mikielewicz
Michał Gliński
ORCID: ORCID

The Baltic Pipe and its impact on energy security in Central and Eastern Europe

Oksana Voytyuk
Polityka Energetyczna - Energy Policy Journal | 2022 | vol. 25 | No 1 | 89-108
Keywords Baltic Pipe energy security gas supplies Poland Central and Eastern Europe
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Abstract

In 2021, the Polish gas transmission system operator GAZ-SYSTEM, in cooperation with the Danish gas and electricity transmission system operator Energinet, began construction of a new gas pipeline from Norway to Poland via Denmark. It will be the first connection of Scandinavian countries with Central-Eastern European countries. The Baltic Pipe gas pipeline is very important for Poland, which is gradually reducing its dependence on Russian gas supplies and strives to expand the energy infrastructure with neighboring countries in order to integrate the Central and Eastern European gas system within the North-South corridor and become a gas hub in this part of Europe. The aim of this article is to answer the following questions: How important is the Baltic Pipe for Poland? Will the gas pipeline have a significant impact on the diversification of gas supplies in short-term and will it contribute to the improvement of the energy security of Central and Eastern Europe in long-term? Will it contribute to the integration of energy systems within the North-South Corridor and the Three Seas Initiative?
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Authors and Affiliations

Oksana Voytyuk
1
ORCID: ORCID
  1. Department of History&International Relations, University in Bialystok, Poland

Neural network approach to compressor modelling with surge margin consideration

Sergiusz Michał Loryś Marek Orkisz
Archives of Thermodynamics | 2022 | vol. 43 | No 1 | 89-108 | DOI: 10.24425/ather.2022.140926
Keywords Modelling Compressor map Neural-network
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Abstract

Artificial neural networks are gaining popularity thank to their fast and accurate response paired with low computing power requirements. They have been proven as a method for compressor performance prediction with satisfactory results. In this paper a new approach of artificial neural networks modelling is evaluated. The auxiliary parameter of ‘relative stability margin Z’ was introduced and used in learning process. This approach connects two methods of compressor modelling such as neuralnetworks and auxiliary parameter utilization. Two models were created, one with utilization of the ‘relative stability margin Z’ as a direct indication of surge margin of any estimated condition, and other with standard compressor parameters. The results were compared by determination of fitting, interpolation and extrapolation capabilities of both approaches. The artificial neural networks used during the process was a two-layer feed-forward neural-network with Levenberg–Marquardt algorithm with Bayesian regularization. The experimental data was interpolated to increase the amount of learning data for the neural network. With the two models created, capabilities of this relatively simple type of neural-network to approximate compressor map was also assessed.
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Authors and Affiliations

Sergiusz Michał Loryś
1
Marek Orkisz
2
  1. Hamilton Sundstrand Poland / Pratt & Whitney AeroPower Rzeszów, Hetmanska 120, 35-078 Rzeszów, Poland
  2. Rzeszow University of Technology, Department of Aerospace Engineering, Powstanców Warszawy 8, 35-959 Rzeszów, Poland

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