Blar i NTNU Open på forfatter "Hafner, Armin"
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Integrated CO2 solutions for supermarkets
Hafner, Armin; Nekså, Petter (Journal article; Peer reviewed, 2018)Supermarkets represent a refrigeration application area which is spearheading towards the total phase in of natural working fluids. Exposed to demanding customers where reputation is an important part of the business, focus ... -
Integrated CO2 system with HVAC and hot water for hotels: Field measurements and performance evaluation
Smitt, Silje Marie; Hafner, Armin; Tolstorebrov, Ignat (Journal article; Peer reviewed, 2020)This study investigates the performance of an integrated CO2 (R744) heat pump and chiller unit in a Norwegian hotel. The system consists of a single unit for heating, cooling and hot water with an integrated thermal storage. ... -
Integrated energy concepts for high performance hotel buildings
Smitt, Silje Marie; Hafner, Armin (Journal article, 2018)Integrated energy concepts with heat recovery are not widely applied for hotels, i.e. there is a huge potential to further reduce the specific primary energy demand in this kind of buildings. The development and implementation ... -
Integrated Energy concepts for high performance hotel buildings
Smitt, Silje Marie (Master thesis, 2017)On a national level, buildings are responsible for roughly 40% of the primary energy consumption, where domestic hot water and space heating are major contributors. By introducing an energy system that employs natural ... -
Integrated energy concepts with CO2 systems for hotel buildings in warm climates
Keshari, Dipak (Master thesis, 2021)Buildings and construction sectors together account for around 36\% of final energy use and 39\% of energy-related carbon dioxide emissions annually according to global status report, with space heating, space cooling and ... -
Integrated energy system for Granåsen Snow Arena, Hotel and Supermarket
Birkeland, Jostein (Master thesis, 2018)Granåsen in Trondheim is the chosen location for Norway s application to host the 2023 FIS Nordic Ski World Championships. One of the investments to develop the area around Granåsen is a new building accommodating a REMA1000 ... -
Integrated heating and cooling CO2 heat pump system in a modern distribution centre
Kvalsvik, Karoline Husevåg; Hafner, Armin (Chapter, 2018)Industry is responsible for about 25-30 % of the global primary energy demand (Elmegaard, Zühlsdorf et al. 2017), and around two thirds of this is used for heating and cooling (Elmegaard, Zühlsdorf et al. 2017). Several ... -
Integrated R744 ejector supportet parallel compression racks for supermarkets : experimental results
Pardiñas, Ángel Á.; Hafner, Armin; Banasiak, Krzysztof (Chapter, 2018)R744 is currently the preferred solution in the commercial refrigeration sector for most regions, but the limited efficiency of such systems under high temperatures constrains its expansion. Technologies such as parallel ... -
Integrated R744 unit for hotels: Analysis of field data
Smitt, Silje Marie; Tolstorebrov, Ignat; Hafner, Armin (Chapter, 2020)This study investigates the performance of an integrated R744 HVAC and domestic hot water unit for a Norwegian hotel. The thermal system of the hotel is described and data from the first year of operation are analyzed. The ... -
Integrated thermal storage and heat recovery of the CO2 refrigeration system for fishing vessels
Saeed, Muhammad Zahid; Widell, Kristina Norne; Hafner, Armin; Nordtvedt, Tom Ståle; Svendsen, Eirik Starheim (Chapter, 2020)The natural refrigerant CO2 is gaining an attraction for fishing vessels due to its compact units, negligible global warming potential (GWP), and non-toxic behaviour. Chilling and freezing onboard are energy-consuming ... -
Integrated thermal system for hydrogen and ammonia driven cruise ship
Egerdahl, Magnus (Master thesis, 2022)Cruiseskipindustrien står overfor utslippsreguleringer på grunn av klimaendringer og global oppvarming. Tradisjonelt fossilt drivstoff som brukes til fremdrift og energibehov ombord på cruiseskip resulterer i et høyt ... -
Integration of a cold thermal energy storage for air conditioning demand in a CO2 refrigeration system of a supermarket
Tommasini, Davide (Master thesis, 2023)There is a significant transition in supermarket refrigeration, with a strong focus on reducing energy demand and installation costs. Generally, industry processes require cooling the most for short periods every day. The ... -
Integration of gravity-fed evaporators in CO2 based heat-pump chillers
Hazarika, Mihir Mouchum; Bengsch, Jan; Hafsås, Johan; Hafner, Armin; Svendsen, Eirik Starheim; Ye, Zuliang (Chapter, 2022)This study is carried out to model a gravity-fed evaporator for CO2 based heat-pump chillers. The gravity-fed evaporator loop consists of a separator, a downcomer, a heat exchanger, and a riser. The working principle is ... -
Integration of R744 and R290 Heat Pumps for Two-family Houses
Plassen, Henrik (Master thesis, 2022)Forbruk av varmt tappevann og romoppvarming er store energiposter, og st˚ar for det meste av energien som leveres til boliger i kalde klima. Varmepumpesystemer utnytter energi i omgivelsene for ˚a redusere bruk av elektrisk ... -
Investigation and analysis of a CO2 heat pump chiller with novel twostage evaporator
Bengsch, Jan (Master thesis, 2022) -
Investigation of advanced supermarket refrigeration units for Scandinavian climates
Martinsen, Tina Alise (Master thesis, 2021)Denne masteroppgaven omhandler analyse av to kjølesystemer gitt av Kelvin AS, som er en av de ledende firmaene innen kjølesystemer til norske matbutikker. Systemene er transkritiske kjølesystemer med CO2 som kuldemedie, ... -
Investigation of CO2 hybrid groundcoupled heat pumping system for warm climate
Jin, Zhequan (Doctoral theses at NTNU;2017:40, Doctoral thesis, 2017)Environmental sustainability, renewable and clean energy utilization and energy conservation have become key issues facing the development of modern society. In the field of refrigeration, air conditioning and heat pumping ... -
Investigation of CO2 refrigeration system and thermal energy storage for passenger ships
Andersen, Henrik; Saeed, Muhammad Zahid; Hafner, Armin; Gabrielii, Cecilia H (Chapter, 2023) -
Investigation of Hydrocarbon Two-phase Flow for Charge Reduced Heat Exchangers
Allymehr, Ehsan (Doctoral theses at NTNU;2021:397, Doctoral thesis, 2021)Hydrocarbons off er an alternative to the HVAC industry as a natural working fluid with minimal environmental impact. The main challenge with hydrocarbons utilization is flammability which can be mitigated by reduction of ... -
Investigation of integrated CO2 heat pumping systems for hotels in cold climates
Smitt, Silje Marie (Doctoral theses at NTNU;2021:391, Doctoral thesis, 2021)