Browsing Institutt for energi og prosessteknikk by Author "Banasiak, Krzysztof"
Now showing items 41-60 of 67
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Next generation of ejector-supported R744 booster systems for commercial refrigeration at all climates
Pardiñas, Ángel Á.; Selvnes, Håkon; Banasiak, Krzysztof; Hafner, Armin (Peer reviewed; Journal article, 2023)The pernicious effects of synthetic refrigerants on different environmental aspects leave natural refrigerants as the only alternative for vapour compressions systems. Among natural refrigerants, CO2 (R744) has become the ... -
Novel integrated CO2 vapour compression racks for supermarkets. Thermodynamic analysis of possible system configurations and influence of operational conditions
Pardiñas, Ángel Á.; Hafner, Armin; Banasiak, Krzysztof (Journal article; Peer reviewed, 2017)An increasing number of supermarket chains are opting for the utilisation of centralised carbon dioxide refrigeration systems. However, the need to improve their efficiency in order to make them economically and environmentally ... -
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 ... -
One-dimensional mathematical modeling of two-phase ejectors: Extension to mixtures and mapping of the local exergy destruction
Wilhelmsen, Øivind; Aasen, Ailo; Banasiak, Krzysztof; Herlyng, Halvor; Hafner, Armin (Peer reviewed; Journal article, 2022)The ejector is a process equipment frequently used in refrigeration processes. There is currently a knowledge gap on the efficiency of ejectors operating with mixtures. To address this knowledge gap, we present a one-dimensional ... -
Optimization of Pipe Geometries with Entropy Production Minimization in Viscous Flow
Herlyng, Halvor (Master thesis, 2022)Hvordan termodynamiske irreversibiliteter i strømningen i ejektorer kan reduseres og hvordan optimalt design av ejektorer skal utføres er enda ikke helt forstått. Ejektorer er utstyr som brukes i forskjellige energiprosesser ... -
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 evaluation of CO2 ejector system with parallel compressor for supermarket application
Singh, Simarpreet; Banasiak, Krzysztof; Hafner, Armin; Maiya, M.P.; Nekså, Petter (Chapter, 2018)Evolution in modifications for CO2 system configuration came across from the last two decades has proven to hold the potential in order to improve the overall performance of the CO2 cooling system for various applications. ... -
Performance Evaluation of Ejector Based CO₂ System for Simultaneous Heating and Cooling Application in an Indian Dairy Industry
Koti, Dasi; Singh, Simarpreet; Guruchethan, A.M.; Maiya, M.P.; Hafner, Armin; Banasiak, Krzysztof; Nekså, Petter (Peer reviewed; Journal article, 2020)India is ranked first in milk production, and its goal is to increase annual production to 300 million tons by 2024. The dairy industry requires multi-temperature cooling and simultaneous heating. In the present study, the ... -
Performance investigation of a multi-ejector R744 heat pump
Singh, Simarpreet; Reddy, Amshith; Prakash, Maiya P.; Banasiak, Krzysztof; Hafner, Armin; Nekså, Petter (Journal article; Peer reviewed, 2018)Carbon dioxide (CO2, R744) is a natural refrigerant which is emerging as a potential substitute for Hydrofluorocarbons (HFCs) and FCs nowadays because of its eco-friendliness, non-flammability, high volumetric capacity and ... -
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 (Journal article; Peer reviewed, 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 ... -
Performance test methodology for the LCCP determination of supermarket and other integrated systems
Pardiñas, Ángel Á.; Hafner, Armin; Banasiak, Krzysztof; Larsen, L. (Chapter, 2017)A new flexible supermarket R-744 refrigeration unit has been implemented in the laboratories at NTNU/SINTEF. The unit is fully equipped with real display cabinets for both medium and low temperature, as well as seven large ... -
Phase change materials for thermal energy storage in low- and high-temperature applications: a state-of-the-art
Sevault, Alexis; Kauko, Hanne; Bugge, Mette; Banasiak, Krzysztof; Haugen, Nils Erland L; Skreiberg, Øyvind (Research report, 2017) -
Possible configurations of multiejector driven CO2 systems for Indian supermarkets
Blust, Stefanie; Hafner, Armin; Banasiak, Krzysztof; Nekså, Petter (Chapter, 2018)An Integrated CO2 Refrigeration Facility is designed for hot climate conditions to improve the basic knowledge of the CO2 refrigeration in India, especially in the supermarket sector. The operational modes can be adapted ... -
R744 ejector technology future perspectives
Hafner, Armin; Banasiak, Krzysztof (Journal article; Peer reviewed, 2016)Carbon Dioxide, CO2 (R744) was one of the first commonly applied working fluids in the infancy of refrigeration more than 100 years ago. In contrast to ammonia it mainly disappeared after the first generation of synthetic ... -
R744 heat pump solutions for electric vehicles
Piesch, Nina; Niroomand, Reza; Hafner, Armin; Banasiak, Krzysztof; Ayad, Fadil (Chapter, 2023) -
R744 Refrigeration Solution for Small Supermarkets
Singh, Simarpreet; Pardiñas, Ángel Á.; Hafner, Armin; Schlemminger, Christian; Banasiak, Krzysztof (Chapter, 2021)Application based technology solution is nowadays preferred to achieve the performance of the cooling system configuration at its best. Therefore, benchmarking is an essential criterion which would add value to the optimum ... -
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 ... -
Strategy for the control of two groups of ejectors operating in parallel in Integrated R744 refrigeration systems
Pardiñas, Ángel Á.; Hafner, Armin; Banasiak, Krzysztof; Kvalsvik, Karoline Husevåg; Larsen, Lars (Chapter, 2018)Commercial refrigeration systems using CO2 as refrigerant are becoming common in the South of Europe, due to technological solutions such as the use of ejectors or parallel compression that allow their efficiency to be ... -
Swirl-Bypass Nozzle for CO2 Two-Phase Ejectors: Numerical Design Exploration
Ringstad, Knut Emil; Banasiak, Krzysztof; Ervik, Åsmund; Hafner, Armin (Journal article; Peer reviewed, 2022)In this work, a novel ejector design concept of a swirl-bypass nozzle is proposed to improve off-design performance of CO2 two-phase ejectors. The swirl-bypass nozzle allows part of the flow to bypass into the ejector ...