Blar i SINTEF Open på forfatter "Palacz, Michal"
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A Concept of performance improvement for R744 two-phase ejector with bypass duct
Bodys, Jakub; Smolka, Jacek; Banasiak, Krzysztof; Palacz, Michal; Haida, Michal; Nowak, Andrzej J. (Science et technique du froid;2018-3, Chapter; Peer reviewed, 2018) -
A gas ejector for CO2 supercritical cycles
Palacz, Michal; Haida, Michal; Smolka, Jacek; Plis, Marcin; Nowak, Andrzej J.; Banasiak, Krzysztof (Journal article; Peer reviewed, 2018)he CO2 ejectors are recently often used as the main expansion device in the modern refrigeration cycles. On the other hand, according to the newest literature the implementation the ejectors into supercritical CO2 power ... -
A modified homogeneous relaxation model for CO2 two-phase flow in vapour ejector
Haida, Michal; Palacz, Michal; Smolka, Jacek; Nowak, Andrzej J.; Hafner, Armin; Banasiak, Krzysztof (Journal article; Peer reviewed, 2016)In this study, the homogenous relaxation model (HRM) for CO2 flow in a two-phase ejector was modified in order to increase the accuracy of the numerical simulations The two- phase flow model was implemented on the effective ... -
Application range of the HEM approach for CO2 expansion inside two-phase ejectors for supermarket refrigeration systems
Palacz, Michal; Smolka, Jacek; Fic, Adam; Bulinski, Zbigniew; Nowak, Andrzej J.; Banasiak, Krzysztof; Hafner, Armin (Peer reviewed; Journal article, 2015)In this study, the accuracy of the homogeneous equilibrium (HEM) applied to 3-D CFD-based simulations of CO2 expansion inside two-phase ejectors is presented. The HEM approach previously reported in the literature were ... -
Experimental study of the heat transfer problem in expansion devices in CO2 refrigeration systems
Mastrowski, Mikolaj; Smolka, Jacek; Hafner, Armin; Haida, Michal; Palacz, Michal; Banasiak, Krzysztof (Journal article; Peer reviewed, 2019)Two expansion devices designed for CO2 refrigeration systems namely, capillary tube and fixed-geometry ejector were experimentally tested in the SINTEF/NTNU laboratory in Trondheim, Norway to determine the influence of ... -
Modified homogeneous relaxation model for the r744 trans-critical flow in a two-phase ejector
Haida, Michal; Smolka, Jacek; Hafner, Armin; Palacz, Michal; Banasiak, Krzysztof; Nowak, Andrzej J. (Journal article; Peer reviewed, 2017) -
Non-equilibrium approach for the simulation of CO2 expansion in two-phase ejector driven by subcritical motive pressure
Bodys, Jakub; Smolka, Jacek; Palacz, Michal; Haida, Michal; Banasiak, Krzysztof (Peer reviewed; Journal article, 2020)A non-equilibrium approach was proposed for highly accurate modelling of the expansion process during two-phase flow in the convergent-divergent motive nozzle of an R744 ejector. Comprehensive mapping of the coefficients ... -
Numerical investigation of heat transfer in a CO2 two-phase ejector
Haida, Michal; Smolka, Jacek; Hafner, Armin; Mastrowski, Mikolaj; Palacz, Michal; Madsen, Kenneth B.; Nowak, Andrzej J.; Banasiak, Krzysztof (Journal article; Peer reviewed, 2018)In this paper, the influence of heat transfer in the walls of an R744 two-phase ejector on ejector performance was investigated. A numerical investigation was performed using a computational fluid dynamic (CFD) model of ... -
Parallel Work of CO2 Ejectors Installed in a Multi-Ejector Module of Refrigeration System
Bodys, Jakub; Palacz, Michal; Haida, Michal; Smolka, Jacek; Nowak, Andrzej J.; Banasiak, Krzysztof; Hafner, Armin (Journal article; Peer reviewed, 2016)A performance analysis on of fixed ejectors installed in a multi-ejector module in a CO2 refrigeration system is presented in this study. The serial and the parallel work of four fixed-geometry units that compose the ... -
Performance improvement of the R744 two-phase ejector With a implemented suction nozzle bypass
Bodys, Jakub; Smolka, Jacek; Banasiak, Krzysztof; Palacz, Michal; Nowak, Andrzej J. (Journal article; Peer reviewed, 2018)In this study, the concept of an R744 ejector with a bypass duct of a suction nozzle was presented. The design of the geometry and bypass positioning in a mixing section, and the idea of regulation, as well as integration, ... -
Performance mapping of the R744 ejectors for refrigeration and air conditioning supermarket application: A hybrid reduced-order model
Haida, Michal; Smolka, Jacek; Hafner, Armin; Ostrowski, Zeimowit; Palacz, Michal; Madsen, Kenneth B.; Försterling, Sven; Nowak, Andrzej J.; Banasiak, Krzysztof (Journal article; Peer reviewed, 2018)The continuous derivation of the ambient temperature and cooling demand in CO2 refrigeration and air-conditioning systems equipped with multi-ejector modules for supermarkets requires the analysis of the fixed ejector ... -
Performance operation of liquid ejectors for a R744 integrated multi-ejector supermarket system using a hybrid ROM
Haida, Michal; Smolka, Jacek; Hafner, Armin; Palacz, Michal; Ostrowski, Zeimowit; Bodys, Jakub; Kriezi, Ekaterini E.; Försterling, Sven; Nowak, Andrzej J.; Banasiak, Krzysztof (Peer reviewed; Journal article, 2019)Performance maps were generated for designed liquid ejectors installed in a multi-ejector module in an R744 integrated supermarket system using a hybrid of the reduced-order model (ROM). Hybrid ROMs of the investigated ... -
Shape optimisation of a two-phase ejector for CO2 refrigeration systems
Palacz, Michal; Smolka, Jacek; Nowak, Andrzej J.; Banasiak, Krzysztof; Hafner, Armin (Journal article; Peer reviewed, 2016)The shape optimisation of four CO2 ejectors is presented in this study. The considered ejectors were originally designed for a multi-ejector supermarket CO2 refrigeration system. The objective function was formulated to ... -
System model derivation of the CO2 two-phase ejector based on the CFD-based reduced-order model
Haida, Michal; Smolka, Jacek; Hafner, Armin; Ostrowski, Zeimowit; Palacz, Michal; Nowak, Andrzej J.; Banasiak, Krzysztof (Journal article; Peer reviewed, 2018)The developed reduced-order model (ROM) of the R744 two-phase ejector was presented in this paper. The proper orthogonal decomposition (POD) model was employed together with the radial basis function (RBF) to evaluate the ... -
The R744 multi-ejector hybrid CFD and experimentally-based reduced-order model
Haida, Michal; Smolka, Jacek; Hafner, Armin; Palacz, Michal; Ostrowski, Zeimowit; Madsen, Kenneth B.; Försterling, Sven; Nowak, Andrzej J.; Banasiak, Krzysztof (Science et technique du froid;2018-3, Chapter; Peer reviewed, 2018)