Blar i NTNU Open på forfatter "Hafner, Armin"
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Development of Transcritical CO2 Heat Pump Chillers
Abdin, Mohammad (Master thesis, 2023)(note: this was done via google translate) Karbondioksid ble først brukt som kjølemiddel på 1850-tallet, først og fremst på grunn av dets naturlige overflod, kostnadseffektivt og ikke-toksisitet. Det begynte da å fases ut ... -
Direct CO2-ground condensers
Hafner, Armin; Kvalsvik, Karoline Husevåg (Chapter, 2018)The utilization of a direct condensing CO2 ground heat exchanger as an auxiliary heat rejection device for commercial or industrial refrigeration applications offers several advantages. During the cold season, and especially ... -
Dynamic energy system with a local LTTG at Leangen
Skulstad, Vegard (Master thesis, 2020)Denne masteroppgaven er en fortsettelse av en tidligere prosjektoppgave og evaluerer bruken av spill-varmekilder for å lage varmtvann til et leilighetsområde. Hovedfokuset er på en oversvømmet fordamper og en CO2 varmepumpe ... -
Dynamic modelling and validation of an air‐to‐water reversible R744 heat pump for high energy demand buildings
Artuso, Paolo; Tosato, Giacomo; Rossetti, Antonio; Marinetti, Sergio; Hafner, Armin; Banasiak, Krzysztof; Minetto, Silvia (Peer reviewed; Journal article, 2021)This paper presents a reversible heat pump based on CO2 as the refrigerant, able to provide heating, cooling, and domestic hot water to high energy demand buildings. The unit was developed and tested under the EU H2020 ... -
Dynamic modelling of local low-temperature heating grids: A case study for Norway
Kauko, Hanne; Kvalsvik, Karoline Husevåg; Rohde, Daniel; Hafner, Armin; Nord, Natasa (Journal article; Peer reviewed, 2017)Today's district heating (DH) networks in Norway are 2nd and 3rd generation systems, with supply temperatures ranging from 80 to 120 °C. In new developments, it is desirable to shift to 4th generation, low-temperature ... -
Effect of subcooling using expander-compressor unit in transcritical CO2
Guruchethan, A.M.; Maiya, M.P.; Hafner, Armin (Chapter, 2022) -
Efficient R744 technology for supermarket heating, cooling and refrigeration - a theoretical assessment of energy advantages in various Spanish cities
Gullo, Paride; Hafner, Armin; Banasiak, Krzysztof (Chapter, 2018)Various appealing expedients aimed at enhancing the energy efficiency of transcritical CO2 (R744) supermarket refrigerating systems have been recently developed. The concurrent adoption of these could lead such hydrofluorocarbon ... -
Ejector for the world: simplified ejector-supported CO2 refrigeration systems for all climates
Pardiñas, Ángel Á.; Fabris, F; Contiero, Luca; Selvnes, Håkon; Banasiak, Krzysztof; Hafner, Armin (Chapter, 2022)The novel configuration presented in this work simplifies the layout of ejector-supported booster systems while maintaining all the benefits of an ejector implementation. The basic version of the solution is based on: i) ... -
Energetic and environmental performance evaluation of AR744 multi-ejector enhanced parallel compression system in high ambient temperature locations
Gullo, Paride; Purohit, Nilesh; Dasgupta, Mani Sankar; Hafner, Armin (Chapter, 2018)Hydrofluorocarbons (HFCs) are widely used today in supermarket refrigeration and air conditioning applications, despite their environmentally deleterious nature. However, the EU F-Gas Regulation 517/2014 ambitiously aims ... -
Energisystem for Fillan skole
Gråberg, Vida Mortensen (Master thesis, 2019)Hitra kommune har som mål å bli mer energieffektive og har på dagsorden å se på energifremmende tiltak. Hovedhensikten med denne masteroppgaven er derfor å kartlegge energibruken til Fillan skole, gi en grunnleggende ... -
Energy distribution concepts for Urban Supermarkets including energy hubs
Selvnes, Håkon; Hafner, Armin (Chapter, 2018)An increasing share of the population on earth is living in urban areas. Using urban building plots for combined purposes will be important in the future. Investors are interested in building new building concepts that ... -
Energy distribution concepts for Urban Supermarkets including energy hubs
Selvnes, Håkon (Master thesis, 2017)More and more of the earths population is living in urban areas. This indicates that using urban building plots for combined purposes will be important in the future. For this reason supermarket chains are developing new ... -
Energy efficient and climate friendly cooling, freezing and heating onboard fishing vessels
Saeed, Muhammad Zahid (Master thesis, 2020)Abstract: Liquefied natural gas (LNG) fueled vessels are increasing in the fishing industry due to its reduced environmental footprint as compared to vessels applying heavy hydrocarbon fuels. Cryogenic tanks are used to ... -
Energy efficient and climate friendly cooling, freezing and heating onboard fishing vessels
Saeed, Muhammad Zahid (Master thesis, 2020)Andelen sjøfartøy som drives av flytende naturgass (LNG) i fiskeindustrien øker på grunn av deres reduserte miljøavtrykk sammenlignet med fartøy som utnytter tunge hydrokarbonbrensler. På skip oppbevares LNG i kryogene ... -
Energy efficient CO2 refrigeration units for fishing vessels
Semaev, Pavel (Master thesis, 2021)Reduksjon i klimagassutslipp fra fiskesektoren er en innsats som krever forskning og utvikling av nyskapende teknologi. Denne masteroppgaven er en del av CoolFish prosjektet, ledet av SINTEF Ocean i samarbeid med flere ... -
Energy efficient multiejector CO2 cooling system for high ambient temperature
Singh, Simarpreet; Maiya, Prakash; Hafner, Armin; Banasiak, Krzysztof; Nekså, Petter (Peer reviewed; Journal article, 2020)Experimental evaluation of a multiejector CO2 cooling system of 33 kW cooling capacity is conducted for an Indian supermarket at high ambient temperature context. The test-rig is designed to depict the actual supermarket ... -
Energy flow analysis of a poultry process plant
Svendsen, Eirik Starheim (Master thesis, 2019)Industriell prosessering av mat innebærer ofte en del forskjellige termiske prosesser som er nødvendige for å gjøre maten trygg for oss mennesker. For bedrifter som produserer og foredler mat betyr dette at de må ha komplekse ... -
Energy flow analysis of a poultry processing plant
Svendsen, Eirik Starheim; Hafner, Armin; Selvnes, Håkon; Widell, Kristina Norne (Chapter, 2020)More efficient utilization of primary energy resources can be achieved with thermal energy storages and it is a measure to limit global warming. The thermal energy demands of industrial food-processing plants are non-uniform ... -
Energy flow analysis of a smart thermal grid at Leangen
Sundal, Eirin Vannes (Master thesis, 2019)På Leangen i Trondheim skal det bli bygget et nytt boligområde. Hensikten med denne masteroppgaven er å evaluere hvordan et lokalt lav-temperatur varmenett kan forsyne boligområdet med energi til romoppvarming, produksjon ... -
Energy flow analysis of an industrial ammonia refrigeration system and potential for a cold thermal energy storage
Widell, Kristina Norne; Svendsen, Eirik Starheim; Selvnes, Håkon; Sevault, Alexis; Hafner, Armin; Nordtvedt, Tom Ståle (Chapter, 2022)There is an increasing effort to reduce energy demand at food processing plants, mainly to reduce the total carbon footprint. The energy demand of a fish processing plant (using ammonia as refrigerant) has been evaluated ...