Browsing NTNU Open by Author "Ahrens, Marcel Ulrich"
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Compressors for 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 compressors. The compressor used for the ammonia compression is a ... -
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 ... -
Exergy analysis of combined absorption-compression heat pump with ammonia-water mixture as working fluid
Ahrens, Marcel Ulrich; Ertesvåg, Ivar Ståle; Eikevik, Trygve Magne (Chapter, 2020)In this paper, investigations on the development of industrial high temperature heat pumps are carried out based on the exergy analysis of different compressor configurations. The combined absorption-compression heat pump ... -
Experimental evaluation of a water based high temperature heat pump with novel high pressure lift turbo compressors
Verpe, Espen Halvorsen; Schlemminger, Christian; Bantle, Michael; Ahrens, Marcel Ulrich (Chapter, 2020)This paper evaluates a water based (R718) high temperature heat pump with novel high-pressure lift turbo compressors. The first stage turbo compressor is designed for steam compression and the second stage is designed for ... -
Höchtemperatur-Wärmepumpen mit natürlichen Kältemitteln : Fallstudien zur HTWP-Integration für industrielle Kälte- und Prozessheisswasserherstellung
Schlemminger, Christian; Ahrens, Marcel Ulrich; Foslie, Sverre Stefanussen; Moen, Ole Marius; Bantle, Michael; Hafner, Armin; Jenssen, Sigmund (Chapter, 2021)Thermische Prozesse in der Nahrungsmittelindustrie, wie z. B. Molkereien sind oftmals eine Kombination aus Erwärmung und Abkühlung eines Produktes. Prozesskühlung wird dabei meistens mittels einer Wärmepumpe erzielt, wobei ... -
Identification of Existing Challenges and Future Trends for the Utilization of Ammonia-Water Absorption–Compression Heat Pumps at High Temperature Operation
Ahrens, Marcel Ulrich; Loth, Maximilian; Tolstorebrov, Ignat; Hafner, Armin; Kabelac, Stephan; Wang, Ruzhu; Eikevik, Trygve Magne (Peer reviewed; Journal article, 2021)Decarbonization of the industrial sector is one of the most important keys to reducing global warming. Energy demands and associated emissions in the industrial sector are continuously increasing. The utilization of high ... -
Integrated CO2 refrigeration and heat pump system for a dairy plant: Energy analysis and potential for cold thermal energy storage
Selvnes, Håkon; Jenssen, Sigmund; Sevault, Alexis Gerard Edouard; Bengsch, Jan; Widell, Kristina Marianne Norne; Ahrens, Marcel Ulrich; Ren, Shuai; Hafner, Armin (Chapter, 2023)Dairy processing is considered very energy-intensive due to significant thermal demands for both cooling and heating at different temperature levels. Conventional dairy plants have separate systems for supplying the various ... -
Integrated CO2 refrigeration and heat pump systems for dairies
Selvnes, Håkon; Jenssen, Sigmund; Sevault, Alexis; Widell, Kristina Norne; Ahrens, Marcel Ulrich; Ren, Shuai; Hafner, Armin (Chapter, 2022)Production facilities in the food industry are large consumers of electricity and thermal energy due to energyintensive processes such as steam production, cleaning, sanitising, refrigeration and drying. Furthermore, there ... -
Integrated high temperature heat pumps and thermal storage tanks for combined heating and cooling in the industry
Ahrens, Marcel Ulrich; Foslie, Sverre Stefanussen; Moen, Ole Marius; Bantle, Michael; Eikevik, Trygve Magne (Peer reviewed; Journal article, 2021)This study investigates the integrated heat pump system of a green-field dairy located in Bergen, Norway. The purpose of the study is to determine the energy consumption and system performance. The dairy features a novel ... -
Investigation on heat recovery strategies from low temperature food processing plants: Energy analysis and system comparison
Ahrens, Marcel Ulrich; Selvnes, Håkon; Henke, Leon Hendrik; Bantle, Michael; Hafner, Armin (Chapter, 2021)Industrial food processing plants often have significant thermal requirements at both low and high temperatures. These plants can produce a variety of products including frozen, chilled and grilled/steamed foodstuff, ... -
Kennfeld und Leistungsanalyse einer zweistufigen Turbokompressor-Brüdenverdichtung
Bantle, Michael; Schlemminger, Christian; Ahrens, Marcel Ulrich; Evenmo, Kjetil (Chapter, 2018)Die mechanische Brüdenverdichtung ist eine Spezialform der Wärmepumpentechnologie. Überschüssiger Dampf aus industriellen Prozessen (R718) wird verdichtet und die Kondensationswärme genutzt um den Prozess zu hei-zen. ... -
Modeling and simulation of oil-free liquid-injected screw compressors using ammonia-water mixture as working fluid
Ahrens, Marcel Ulrich; Tønsberg, Even Kristian; Tolstorebrov, Ignat; Hafner, Armin; Eikevik, Trygve Magne (Chapter, 2022)This study investigates the compression process of an oil-free screw compressor with liquid injection for an absorption-compression heat pump (ACHP) with an ammonia-water mixture as working fluid. In recent years, several ... -
Modelling Approach for a Liquid-Injected Ammonia-Water Screw Compressor
Ahrens, Marcel Ulrich; Tønsberg, Even Kristian; Tolstorebrov, Ignat; Hafner, Armin; Eikevik, Trygve Magne (Chapter, 2021)The present work focuses on a modelling approach for a liquid-injected ammonia-water screw compressor for combined absorption-compression heat pumps (CACHP) at high-temperature operation. The CACHP system combines the ... -
Numerical investigation of an ammonia-water absorption-compression high-temperature heat pump for hot water and steam production in food processing
Ren, Shuai; Ahrens, Marcel Ulrich; Hamid, Khalid; Tolstorebrov, Ignat; Hafner, Armin; Eikevik, Trygve Magne; Widell, Kristina Marianne Norne (Chapter, 2023)To achieve climate neutrality in the food sector, there is an urgent need for eco-friendly steam boilers. The absorption-compression heat pumps (ACHP) using an ammonia-water mixture as working fluid can provide a high heat ... -
Numerical investigation of an oil-free liquid-injected screw compressor with ammonia-water as refrigerant for high temperature heat pump applications
Ahrens, Marcel Ulrich; Tolstorebrov, Ignat; Tønsberg, Even Kristian; Hafner, Armin; Wang, Ruzhu; Eikevik, Trygve Magne (Peer reviewed; Journal article, 2022)This study investigates a numerical model of an oil-free twin screw compressor with an ammonia-water mixture as refrigerant and liquid injection. The compressor was identified as the main constraint to increase the heat ... -
Performance analysis of high temperature heat pumps and thermal energy storages for a dairy
Ahrens, Marcel Ulrich; Brækken, August; Foslie, Sverre Stefanussen; Moen, Ole Marius; Lovas, Kim Andre; Bantle, Michael; Hafner, Armin; Eikevik, Trygve Magne (Chapter, 2022)This paper analyses the performance of the integrated energy system of an existing dairy in Bergen, Norway. The investigated dairy has an innovative solution for the thermal process supply by using only heat pumps and ... -
Performance evaluation of high-temperature heat pump systems for hot water and steam generation in food processing
Ren, Shuai; Ahrens, Marcel Ulrich; Hafner, Armin; Widell, Kristina Norne (Chapter, 2022)A large amount of fossil fuels is consumed for hot water and steam generation in food processes such as smoking, scalding, drying, pasteurization, sterilization, cleaning, and cooking, which currently rises both economic- ... -
Potential evaluation of integrated high temperature heat pumps: A review of recent advances
Hamid, Khalid; Sajjad, Uzair; Ahrens, Marcel Ulrich; Ren, Shuai; Palanichamy, Ganesan; Tolstorebrov, Ignat; Arshad, Adeel; Said, Zafar; Hafner, Armin; Wang, Chi-Chuan; Wang, Ruzhu; Eikevik, Trygve Magne (Peer reviewed; Journal article, 2023) -
Turbo-compressors for R-718: Experimental evaluation of a two-stage steam compression cycle
Bantle, Michael; Schlemminger, Christian; Gabrielii, Cecilia H; Ahrens, Marcel Ulrich (Chapter, 2019)Water (R-718) is a safe and energy-efficient refrigerant. Mechanical vapour recompression (MVR), an open-loop heat pump using R718, can significantly reduce the energy consumption for steam-heated processes like drying, ...