Blar i NTNU Open på forfatter "Hafner, Armin"
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Data-driven modelling of a R744 refrigeration system with parallel compression configuration
Andreasen, Glenn; Stoustrup, Jakob; Pardiñas, Ángel Á.; Hafner, Armin; Izadi-Zamanabadi, R. (Chapter, 2019)The type and characteristics of the employed components, subsystems and refrigerant in a commercial refrigeration system varies significantly depending on required functionalities (e.g. MT (medium temperature), LT (low ... -
Depressurization of CO2 in pipes: Analysis of experiments and non-equilibrium flashing flow models
Log, Alexandra Metallinou (Doctoral theses at NTNU;2023:427, Doctoral thesis, 2023)CO2 capture and storage is expected to play a vital role in reaching net zero emissions by 2050. In this context, large-scale CO2 pipeline transportation networks must be deployed. In order to perform safety analyses and ... -
Depressurization of in a pipe: Effect of initial state on non-equilibrium two-phase flow
Log, Alexandra Metallinou; Hammer, Morten; Deng, Han; Austegard, Anders; Hafner, Armin; Munkejord, Svend Tollak (Peer reviewed; Journal article, 2023)It is key in several industrial applications to accurately describe rapid depressurization of liquid and dense phase states. Examples include refrigeration systems, nuclear reactor cooling and capture and storage (CCS). ... -
Design and Evaluation of CO2 based integrated heating and cooling systems for zero emission cruise ships
Schaan, Larissa (Master thesis, 2021)Fremtidige kjølesystemer for cruiseskip er underlagt stadig strengere begrensninger på kjølemidler og bør også bidra til å øke skipets samlede energieffektivitet. På denne bakgrunn handler den nåværende vitnemålet om ... -
Design and simulations of Refrigerated Sea Water Chillers with CO2 ejector pumps for marine applications in hot climates
Bodys, Jakub (Master thesis, 2017)According to provided literature review, many investigations concerned improvement possibilities of carbon-dioxide refrigeration units. Basis for further development of this technology are located in environmentally friendly ... -
Design and simulations of refrigerated sea water chillers with CO2 ejector pumps for marine applications in hot climates
Bodys, Jakub; Hafner, Armin; Banasiak, Krzysztof; Smolka, Jacek; Ladam, Yves (Journal article; Peer reviewed, 2018)Various system configurations have been developed to improve the R744 systems under hot ambient conditions. However, stationary land applications are characterised by negligible limits on space for system equipment, unlike ... -
Design of a cold thermal energy storage unit for industrial applications using CO2 as refrigerant
Selvnes, Håkon; Hafner, Armin; Kauko, Hanne (Chapter, 2019)Natural refrigerants such as ammonia, hydrocarbons and CO2 are becoming increasingly popular due to favorable thermo-physical properties, low environmental impact and low cost. Industrial refrigeration systems are often ... -
Design of refrigeration system for freeze-concentration of fish protein hydrolysates using CO2 as working fluid
Leth-Olsen, Jomar Mandal (Master thesis, 2022)Foredling av fisk etterlater store mengder restmateriale kun benyttet til lavkvalitets biprodukter. I noen tilfeller kan restmaterialet utgjøre over 50% av den totale vekten av hvit fisk. Utnyttelse av den høye næringsmengden ... -
Designing and Implementation of a Plate Freezer Test facility applying R744 at around -50°C
Mposola, Emmanuel (Master thesis, 2023)Klimaendringer er en trussel mot eksistensen av økosystemer og planeten for øvrig, noe som kreves reevaluering av menneskeskapte aktiviteter som over år har bidratt til utarming av ozonlaget og utslipp av klimagasser. Mat ... -
A detailed review on CO2 two-phase ejector flow modeling
Ringstad, Knut Emil; Allouche, Yosr; Gullo, Paride; Ervik, Åsmund; Banasiak, Krzysztof; Hafner, Armin (Peer reviewed; Journal article, 2020)Ejector-equipped vapor-compression systems for refrigeration and cooling, relying solely on (R744) as a natural working fluid, are perceived to be an eco-friendly and highly efficient solution for many applications. However, ... -
A detailed review on CO2 two-phase ejector flow modeling
Ringstad, Knut Emil; Allouche, Yosr; Gullo, Paride; Ervik, Åsmund; Banasiak, Krzysztof; Hafner, Armin (Peer reviewed; Journal article, 2020)Ejector-equipped vapor-compression systems for refrigeration and cooling, relying solely on (R744) as a natural working fluid, are perceived to be an eco-friendly and highly efficient solution for many applications. However, ... -
Development and validation of CO2 cooling systems with expansion work recovery
Saeed, Muhammad Zahid (Doctoral theses at NTNU;2024:286, Doctoral thesis, 2024)The 2023 revised strategy of the International Maritime Organization (IMO) emphasises achieving net-zero greenhouse gas emissions within the shipping sector. Notably, nearly 40% of the energy demand in passenger ships is ... -
Development of a fossil-free heating system for chicken barns based on heat pumps and thermal storage
Thapa, Saroj (Master thesis, 2023)Mens det globale forbruket av fjørfekjøtt fortsetter sin oppadgående trend, rettes det uunngåelige søkelyset mot den betydelige miljøpåvirkningen, spesielt de betydelige CO2-utslippene knyttet til konsum av kyllingkjøtt. ... -
Development of a methodology for the determination of the life cycle climate performance (LCCP) of supermarket refrigeration systems and other integrated system with a reduced number of experiments
Durand, Aymeric (Master thesis, 2018)The SuperSmart Rack is an innovative prototype of a refrigeration system running with CO2 as only refrigerant with the aim to reduce the environmental impacts. It is discussed in the present report how to assess these ... -
Development of Ammonia-Water Hybrid Absorption- Compression Heat Pumps
Ahrens, Marcel Ulrich; Hafner, Armin; Eikevik, Trygve Magne (Chapter, 2019)In this paper, investigations on the development of industrial high temperature heat pumps are carried out based on the analysis of the current available components. Ammonia-water hybrid heat pumps combine technologies of ... -
Development of an ammoniawater absorption-compression heat pump at high temperature operation
Ahrens, Marcel Ulrich (Doctoral theses at NTNU;2023:39, Doctoral thesis, 2022)Decarbonization of the industrial sector is one of the most important measures to tackling global warming. Energy demand and associated greenhouse gas (GHG) emissions are continuously increasing in various industrial ... -
Development of CO2 refrigeration systems and thermal energy storage for cruise ships
Andersen, Henrik (Master thesis, 2022)Kjølemedier som er brukt om bord på cruiseskip i dag er assosiert med en betydelig innvirkning på global oppvarming. Disse kjølemediene blir stadig mer regulert, noe som understreker viktigheten av å bruke bærekraftige ... -
Development of cold thermal energy storage for industrial refrigeration applications
Selvnes, Håkon (Doctoral theses at NTNU;2022:387, Doctoral thesis, 2022)Refrigeration technology is a vital part of modern society, covering multiple applications from comfort cooling and process cooling of servers in data centres, to domestic, commercial, and industrial refrigeration systems. ... -
Development of Concentration Processes to Conserve Rest Raw Materials and Process Water in onshore and off-shore Sectors for Circular Economy
Neakakhtar, Faraz (Master thesis, 2023)Fiskekonsum og ressursutnyttelse har ført til behovet for bærekraftige praksiser på grunn av begrensede fiskeressurser og ønske om bedre utnyttelse av fiskeavfall. Ifølge Caruso (2016) produserer fiskerier over hele verden ... -
Development of local energy recovery and distribution
Vestgren, Susanne (Master thesis, 2020)+CityxChange er et prosjekt med et mål om å forbedre ressursutnyttelsen i byene på best mulig måte ved å installere ny teknologi [+CityxChange, 2019]. En del av prosjektet foregår på Sluppen i Trondheim, og målet er at ...