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1

Reliability model of the RTC System with trackside equipment equipped with a Peltier cell

Kowalik Rafał, Sadowski Emil

Journal of civil engineering and transport

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2020

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Vol. 2, No. 2

99--108

EN

The article presents a mathematical model assessing the reliability of rail traffic control systems with a mounted Peltier cell. The semiconductor element will be used for operating electronic components that are in the trackside equipment. In the prepared model, Markow processes were used to describe the states occurring between individual components of the RTC System. Simulation tests were mainly based on determining the average time of component failure. The presented results were carried out for 1,000, 2,000 and 3,000 rail vehicle crossings over the railway tracks equipped with RTC Systems. At the very end of the article the conclusions resulting from computer simulations were presented.

PL

W artykule przedstawiono model matematyczny oceniający niezawodność systemów sterowania ruchem kolejowym z zamontowanym ogniwem Peltiera. Element półprzewodnikowy zostanie wykorzystany do obsługi elementów elektronicznych znajdujących się w urządzeniach torowych. W przygotowanym modelu wykorzystano procesy Markowa do opisu stanów występujących pomiędzy poszczególnymi elementami systemu SRK. Testy symulacyjne polegały głównie na określeniu średniego czasu uszkodzenia elementu. Przedstawione wyniki przeprowadzono dla 1000, 2000 i 3000 przejazdów pojazdów szynowych nad torami kolejowymi wyposażonymi w systemy SRK. Na samym końcu artykułu przedstawiono wnioski wynikające z symulacji komputerowych.

2

The possibilities of the use of waste heat from low temperature PEM fuel cells

Ogulewicz W., Węcel D.

Journal of Energy Science

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2012

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Vol. 1, nr 2

59--69

EN

Low temperature PEM fuel cells generate electricity with an efficiency of the order of 50%. The remaining chemical energy of the fuel is converted into heat with a relatively low temperature. The working temperatures of PEM fuel cells usually do not exceed 80-90°C to prevent damage to the membrane material. This requires the cooling of the fuel cells, and the heat with a temperature of about 70°C obtained in the process may generally be used only for heating purposes. In order to improve the electricity generation efficiency of the PEM fuel cells (PEMFC), it is proposed that Peltier semiconductor thermoelectric modules should be used as thermogenerators. This solution allows a conversion of heat into electricity from a low temperature source. This process is completed in a direct energy conversion device. Water-cooled PEMFC stacks are used in the conducted studies. This solution makes it possible to use the waste heat in a specially designed heat exchanger beyond the fuel cell. For the research purposes, a device is constructed which is composed of two thermally insulated water chambers with Peltier modules in between. One of the chambers is fed with hot liquid from the PEMFC cooling cycle. The other chamber, fed with a cold liquid, makes it possible for the heat to flow through Peltier thermoelectric modules, converting heat into electricity. In such systems it is very difficult to obtain an effective heat flow in the exchanger and to ensure a relatively large temperature difference between the upper and the lower heat source. This problem may be solved by using the concept proposed in this paper, i.e. by placing Peltier modules inside individual fuel cells. As a result, a compact structure is obtained, which allows a minimization of possible energy losses and a reduction in the device weight. This, however, requires appropriate cooling (maintaining a low temperature) on what is referred to as the Peltier cell cold side. Additionally, owing to the fact that Peltier cells may operate as a "heat pump" or as a thermogenerator, extra assistance is obtained in the fuel cell for the generation of either electricity or heat, depending on the needs.

3

Koncepcja stanowiska badawczego: ogniwo fotowoltaiczne - generator wodoru - ogniwo paliwowe

Ogulewicz W., Węcel D., Wiciak G., Łukowicz H.

Rynek Energii

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2010

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nr 2

108-112

PL

W pracy zaprezentowano wybrane zagadnienia zastosowania ogniw paliwowych w układach wykorzystujących słoneczną energię odnawialną. Energia elektryczna ogniw fotowoltaicznych zasila elektrolizery generatorów wodoru. Uzyskane paliwo wodorowe utleniane w ogniwach paliwowych wytwarza energię elektryczną zgodnie z profilem zapotrzebowania odbiorców. W procesie utleniania wodoru w ogniwach paliwowych powstaje również ciepło. Zaproponowano sposób konwersji ciepła odpadowego z chłodzenia ogniw paliwowych w energię elektryczną z użyciem półprzewodnikowych modułów termoelektrycznych Peltiera. W artykule wyszczególniono założenia projektu badawczo-rozwojowego ogniwa paliwowego typu PEM oraz omówiono koncepcje instalacji badawczych realizowanych w Instytucie Maszyn i Urządzeń Energetycznych. Przedstawiono sugestie i wnioski dotyczące potencjalnych zastosowań tej technologii w energetyce uwzględniające obecny poziomu za-awansowania badań.

EN

Selected problems connected to the use of fuel cells in energy-system with solar renewable energy are introduced in the paper. Electric energy from photovoltaic cells supply electrolysers in hydrogen generators. Solar generated hydrogen fuel is oxidized in fuel cells and produce electric energy according to the electrical power requirement of the receivers. During oxidation process in fuel cells also heat is generated. The method of waste heat conversion from fuel cells cooling system to electric power was proposed using semiconductor thermoelectric Peltier cells. In this article were specified guiding principles of research and development project of PEM fuel cell and conception of research system made in Institute of Power Engineering and Turbomachinery was discussed. There were presented suggestions and conclusions related to potential application of that technology in power industry, take into account the advanced research level.