Blar i NTNU Open på forfatter "Hafner, Armin"
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Energy Saving Solutions on Cooling and Ventilation Systems at CERN under the aspect of heat recovery
Gioti, Evangelia (Master thesis, 2023)M ̊alet med denne rapporten er ̊a kartlegge de eksisterende systemene ved CERN campus og ̊a foresl ̊a alternative, mer energieffektive løsninger. Det vil spesifikt fokuseres p ̊a ̊a undersøke eksisterende kjøle- og ... -
Energy Systems For Salmon Process Plants
Putlur Yeshwanth Kumar, Hiran (Master thesis, 2023)Lakseoppdrett, en viktig hjørnestein i Norges økonomi og dens nest største eksport, krever kompliserte, energikrevende operasjoner. Moderne lakseprosesseringsanlegg bruker en rekke spesialiserte energisystemer, inkludert ... -
Energy use and retrofitting potential of heat pumps in cold climate hotels
Smitt, Silje Marie; Tolstorebrov, Ignat; Gullo, Paride; Pardiñas, Ángel Á.; Hafner, Armin (Peer reviewed; Journal article, 2021)Tourism, and thereby hotels, play a crucial role in the European economy. The hotel sector features high energy consumption, which greatly contributes to the global warming effect. Thus, there is a need to investigate ... -
Energy-efficient Supermarket CO2 Compressor Pack with Ejectors
Han, Yi (Master thesis, 2017)In this thesis, the background of re-implementation of CO2 and the description of refrigeration cycles with R744 compressor and ejector are introduced at first. The following is a case study performed to set up the R744 ... -
Evaluation of a pillow-plate heat exchanger for a pump-circulated CO2 refrigeration system
Selvnes, Håkon; Büttner, Vera; Hafner, Armin (Chapter, 2020)Cold thermal energy storage (CTES) technology integrated into refrigeration systems has been proposed as a solution for peak shaving of refrigeration demands. This paper presents the results obtained from an experimental ... -
Evaluation of a reversible NH3 heat pump unit
Amundsen, Lars-Adrian (Master thesis, 2019)Denne rapporten er laget for å evaluere en reversibel NH3 varmepumpe som GK har installert i sitt kontorbygg i Folke Bernadottes Vei 40 i Bergen. Rapporten tar for seg teoretisk bakgrunnsmateriale relevant for NH3-systemer, ... -
Evaluation of different concepts for the utilization of the cooling potential from the regasification of natural gas
Øverby, Tone (Master thesis, 2018)The increasing interest in energy efficient solutions, and working towards a more sustainable future, give rise to the importance of utilization and thus reduction of the current wastage of excess energy today. As the total ... -
Evaluation of Integrated Concepts with CO2 for Heating, Cooling and Hot Water Production
Smitt, Silje Marie; Pardiñas, Ángel Á.; Hafner, Armin (Journal article; Peer reviewed, 2021)The hotel sector is characterized by high thermal demands and a large carbon footprint, which greatly contributes to the global warming effect. Consequently, there is a need to investigate solutions that can reduce energy ... -
Evaluation of possible heat pump configurations for waste heat recovery at +CityXChange Sluppen
Balstad, Erlend Nytrø (Master thesis, 2020)Klimautfordringene har skapt et behov for økt ressursutnyttelse og innovative løsninger. Formålet med +CityxChange, en del av Horizon 2020, er å etablere pilotprosjekter med innovative energiløsninger. Formålet med denne ... -
Evaporative cooling system with natural refrigerant at -50 ℃ and 100 m underground
Barroca, Pierre; Hafner, Armin; Álvarez Pardiñas, Ángel; Verlaat, B; Zwalinski, L; Hulek, Wojciech; Petagna, P.; Hanf, Pierre; Battistin, M (Chapter, 2020)The cooling systems of the future tracking detectors of both ATLAS and CMS experiments at the Large Hadron Collider (LHC) at CERN will be entirely based on CO2 refrigeration technology. The system is a booster refrigeration ... -
Experimental analysis of advanced R744 refrigeration system
Contiero, Luca (Master thesis, 2020)Carbon dioxide is one of the oldest refrigerants, as it was used widely at the end of the nineteenth century. However, around 1931 it started its decline when synthetic refrigerants came into the market showing a higher ... -
Experimental analysis of an advanced R744 multi-ejector
Selnes, Merethe Leksen (Master thesis, 2020)Den økende interessen for energieffektive løsninger, samt å arbeide mot en mer bærekraftig framtid, viser til viktigheten av å spare energi. Dagens butikkjøleanlegg med karbondioksid har et stort potensial for å redusere ... -
Experimental and computational analysis of a R744 flashing ejector
Giacomelli, Francesco; Mazzelli, Federico; Banasiak, Krzysztof; Hafner, Armin; Milazzo, Adriano (Journal article; Peer reviewed, 2019)In this paper we present a set of experimental data acquired on a CO2 flashing ejector designed for expansion loss recovery applications. Experimental results are compared with CFD simulations obtained using a Homogeneous ... -
Experimental and numerical investigation on a ejector for CO2 vapor compression systems
Giacomelli, Francesco; Banasiak, Krzysztof; Hafner, Armin; Mazzelli, Frederico; Milazzo, Adriano (Chapter, 2018)The use of two-phase flashing ejectors to improve the COP and capacity of CO2 vapor compression systems has become a key research topic in recent years. Although many experimental investigations focused on both the ejector ... -
Experimental characterisation of a cold thermal energy storage unit with a pillow-plate heat exchanger design
Selvnes, Håkon; Allouche, Yosr; Hafner, Armin (Peer reviewed; Journal article, 2021)Cold Thermal Energy Storage (CTES) technology can be introduced to refrigeration systems for air conditioning and process cooling to reduce the peak power consumption by decoupling the supply and demand of refrigeration. ... -
Experimental Evaluation of a Multi-Ejector Trans-critical CO2 System for Supermarkets
Singh, Simarpreet; Hafner, Armin; Banasiak, Krzysztof; Maiya, Prakash; Nekså, Petter (Chapter, 2019)In the present experimental study, the performance of a multi-ejector based trans-critical CO2 cooling system is tested at high ambient temperature up to 46°C for a supermarket application with and without internal heat ... -
Experimental evaluation of multi-ejector based CO2 cooling system for supermarkets in tropical zones
Singh, Simarpreet; Hafner, Armin; Banasiak, Krzysztof; Maiya, Prakash M.; Nekså, Petter (Chapter, 2018)Cooling system for supermarkets, now-a-days in developing countries like India, mainly uses man-made synthetic refrigerants/mixtures such as R134a, R404A and R410A (HFCs). These fluorinated refrigerants possess an outrageous ... -
Experimental evaluation of the performance of an ejector for a single compression multi-temperature CO2 refrigeration unit
Fabris, F; Pardiñas, Ángel Á.; Marinetti, Sergio; Rossetti, Antonio; Hafner, Armin; Minetto, Silvia (Chapter, 2022)A novel vapor-compression system concept employing carbon dioxide as the refrigerant is proposed to serve the needs of a typical medium-size refrigerated truck used for multi-temperature (MT and LT) goods delivery. The ... -
Experimental Investigation of a ColdThermal Energy Storage System for Industrial Application
Sakka Amini, Saleh (Master thesis, 2021)Denne rapporten presenterer resultatene av eksperimentelle undersøkelser om ytelsen til et CTESsystem som er designet for ˚a integreres med et industrielt NH3/CO2 kaskadekjølesystem for et kjøttforedlingsanlegg for ... -
Experimental investigation of a hightemperature heat pump for food processing applications
Dano, Timothée (Master thesis, 2023)I dag involverer mesteparten av dampproduksjonen til matforedlingsformål fossil drivstoff. For å ta tak i klimaspørsmålet er det presserende å fremme utvikling av miljøvennlige løsninger for dampproduksjon. Absorpsjonsko ...