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Search results for: NTU (NUM- BER OF HEAT TRANSFER UNITS)
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Improvement of the thrust bearing calculation considering the convectional heating within the space between the pads
PublicationA modern thrust bearing calculation tool should consider not only the oil film between pad and rotating collar but also the space between the pads. The oil flow in the space has a significant influence on the oil film inlet temperature, the convectional cooling of pad and collar and should be included in the bearing calculation methods. The authors use a tool developed at Clausthal University of Technology in cooperation with the...
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Operation evaluation method for marine turbine combustion engines in terms of energetics
PublicationAn evaluation proposal (quantitative determination) of an y combustion turbine engine operation has been presented , wherein the impact energy occurs at a given time due to Energy conversion. The fact has been taken into account that in this type of internal combustion engines the energy conversion occurs first in the combustion chambers and in the spaces between the blade of the turbine engine. It was assumed that in the combustion...
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Experimental investigation on heat pipes supported by soy wax and lauric acid for electronics cooling
PublicationThis paper presents an experimental study of heat pipes for electronics cooling that were supported by energy storage materials (i.e. phase change materials - PCMs) coated at the adiabatic section. The PCMs utilized included two materials, namely lauric acid and soy wax, the latter being considered as a more cost-effective alternative. The study focused on three different powers: 20 W, 25 W, and 30 W. Both heating, cooling, and...
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Looking for a minimum exergy destruction in hierarchical cycle
PublicationThe paper presents results of energy analysis, complemented with an exergy balance, of hierarchical thermodynamic cycle. Proposed cycle is a binary vapour cycle based on a model of real supercritical steam power plant. Energy analysis is used to preliminary optimization of the cycle and the exergy losses analysis is proposed to perform optimization of heat transfer processes, which are essential for hierarchical cycles. Proposed...
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Exergy Losses in the Szewalski Binary Vapor Cycle
PublicationIn this publication, we present an energy and exergy analysis of the Szewalski binary vapor cycle based on a model of a supercritical steam power plant. We used energy analysis to conduct a preliminary optimization of the cycle. Exergy loss analysis was employed to perform a comparison of heat-transfer processes, which are essential for hierarchical cycles. The Szewalski binary vapor cycle consists of a steam cycle bottomed with...
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Progress in module design for membrane distillation
PublicationThere have been tremendous advances in membrane distillation (MD) since the concept was introduced in 1961: new membrane designs and process configurations have emerged, and its commercial viability has been evaluated in several pilot-scale studies. However, its high energy consumption has hindered its commercialization. One of the most promising ways to overcome this obstacle is to develop more energy-efficient membrane modules....
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Modelling and simulation of GPU processing in the MERPSYS environment
PublicationIn this work, we evaluate an analytical GPU performance model based on Little's law, that expresses the kernel execution time in terms of latency bound, throughput bound, and achieved occupancy. We then combine it with the results of several research papers, introduce equations for data transfer time estimation, and finally incorporate it into the MERPSYS framework, which is a general-purpose simulator for parallel and distributed...
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Exergetic Analysis of the nCO2PP Cycle with Particular Reference to the Exergy Destruction of Sewage Sludge Due to Gasification
PublicationAn exergy analysis is carried out on the negative CO2 emission gas power plant (nCO2PP), which integrates the process sections of fuel preparation, power generation and carbon capture. Processes of exergy destruction are studied with particular focus on the process in the gasification unit of the fuel preparation section, where a large amount of exergy is destroyed in various chemical reactions from sewage sludge to producer gas...
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Thermomagnetic behavior of a semiconductor material heated by pulsed excitation based on the fourth-order MGT photothermal model
PublicationThis article proposes a photothermal model to reveal the thermo-magneto-mechanical properties of semiconductor materials, including coupled diffusion equations for thermal conductivity, elasticity, and excess carrier density. The proposed model is developed to account for the optical heating that occurs through the semiconductor medium. The Moore–Gibson–Thompson (MGT) equation of the fourth-order serves as the theoretical framework...
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Determination of Thermophysical Parameters Involved in The Numerical Model to Predict the Temperature Field of Cast-In-Place Concrete Bridge Deck
PublicationThe paper dealswith a concept of a practical computationmethod to simulate the temperature distribution in an extradosed bridge deck. The main goal of the study is to develop a feasible model of hardening of concrete consistent with in-situ measurement capabilities. The presented investigations include laboratory tests of high performance concrete, measurements of temperature evolution in the bridge deck and above all, numerical...
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Efficiency of thermomechanical reclaiming of ground tire rubber conducted in counter-rotating and co-rotating twin screw extruder
PublicationIn this article the results of research on a continuous thermomechanical reclaiming process of ground tire rubber (GTR) conducted in a twin screw extruder are presented. The effects of the rotation direction (co-rotating/counter-rotating), design of co-rotating plasticizing units and the rotational speed of the screws on the extruder working parameters, sol fraction and the degree of reclaiming in the obtained products were described....
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Nodal models of Pressurized Water Reactor core for control purposes – A comparison study
PublicationThe paper focuses on the presentation and comparison of basic nodal and expanded multi-nodal models of the Pressurized Water Reactor (PWR) core, which includes neutron kinetics, heat transfer between fuel and coolant, and internal and external reactivity feedback processes. In the expanded multi-nodal model, the authors introduce a novel approach to the implementation of thermal power distribution phenomena into the multi-node...
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Mikropompa elektrohydrodynamiczna na ciecz dielektryczną zasilana napięciem stałym
PublicationW niniejszym artykule zaprezentowano projekt i działanie miniaturowej pompy elektrohydrodynamicznej (EHD) zasilanej napięciem stałym przeznaczonej do chłodzenia elementów elektronicznych. Zmierzono natężenie przepływu cieczy oraz ciśnienie wytwarzane przez pracującą mikropompę. Maksymalne natężenie przepływu, 0,5 ml/min, uzyskano dla napięcia 12 kV. Zmierzone ciśnienie wyniosło 500 Pa przy przyłożonym napięciu 6 kV. Maksymalny...
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Clays as Inhibitors of Polyurethane Foams’ Flammability
PublicationPolyurethanes are a very important group of polymers with an extensive range of applications in different branches of industry. In the form of foams, they are mainly used in bedding, furniture, building, construction, and automotive sectors. Due to human safety reasons, these applications require an appropriate level of flame retardance, often required by various law regulations. Nevertheless, without the proper modifications,...
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A Comparison of Empirical Correlations of Viscosity and Thermal Conductivity of Water-Ethylene Glycol-Al2O3 Nanofluids
PublicationBecause of their superb thermal conductivity, nanofluids are seen as new generation of cooling mediums in many engineering applications. It is well established that even a small amount of nanoparticles mixed with a base fluid may result in distinct thermal conductivity enhancement. On the other hand, addition of nanoparticles to the base fluid results in its substantial viscosity increase. Therefore, it is very dicult to evaluate...
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Olfactory receptor-based biosensors as potential future tools in medical diagnosis
PublicationThe detection of biomarkers is the future of non-invasive medical diagnosis and screening. Discovery and identification of reliable disease specific volatile organic compounds is dependent on repeatable, accurate analysis of trace level gaseous analytes mainly in breath samples. Natural variety of the olfactory systems and the compounds capable of gas molecules binding creates wide possibilities of acquisition and implementation...
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Multi-pathway mechanism of polydopamine film formation at vertically aligned diamondised boron-doped carbon nanowalls
PublicationBoron-doped carbon nanowall (B:CNW) electrodes were used as a platform for studying the electropolymerisation of dopamine. Due to the unique properties of B:CNW, including the fast charge-transfer kinetics and high surface conductivity, a high degree of reversibility of redox reactions was achieved. Three separated redox peaks were observed on voltammograms and attributed to three fundamental reactions in the dopamine polymerisation...
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Organic Supercritical Thermodynamic Cycles with Isothermal Turbine
PublicationOrganic Rankine cycles (ORC) are quite popular, but the overall efficiencies of these plants are rather very low. Numerous studies have been conducted in many scientific centers and research centers to improve the efficiency of such cycles. The research concerns both the modification of the cycle and the increase in the parameters of the medium at the inlet to the turbine. However, the efficiency of even these modified cycles rarely...
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Prognozowanie właściwości złączy spawanych pod wodą metodą lokalnej komory suchej
PublicationNiniejsza praca jest poświęcona spawaniu pod wodą metodą lokalnej komory suchej (MLKS) i przedstawia metodologię oraz narzędzia umożliwiające prognozowanie właściwości złączy spawanych wykonanych przy zastosowaniu tej odmiany spawania. Monografia zawiera opis rozwoju spawania pod wodą oraz charakterystykę metod wykorzystywanych do realizacji prac spawalniczych. Zaproponowano nowy podział metod spawania pod wodą, uwzględniający...
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Anna Wałek dr
PeopleDr Anna Wałek, President of IATUL – International Association of University Libraries, director of the Gdańsk University of Technology Library. An experienced library manager, an expert in the field of Open Science, and organization and management of a scientific library. She conducts scientific research in data management in various scientific disciplines, metadata for research data, and data management support services - incl....