2025

• Hamid, Khalid; Ren, Shuai; Tolstorebrov, Ignat; Hafner, Armin; Sajjad, Uzair; Arpagaus, Cordin. (2025) Experimental optimization of an absorption-compression heat pump with wet compression for large temperature glide industrial applications. Renewable Energy
  Academic article
• Hamid, Khalid; Ren, Shuai; Tolstorebrov, Ignat; Hafner, Armin; Wang, Chi-Chuan; Sajjad, Uzair. (2025) Development and experimental assessment of oil free combine absorption-compression heat pump with NH<inf>3</inf>/H<inf>2</inf>O mixture working fluid. Applied Energy
  Academic article

2024

• Ren, Shuai; Hafner, Armin; Rekstad, Inge Håvard; Widell, Kristina Marianne Norne; Svendsen, Eirik Starheim; Nordtvedt, Tom Ståle. (2024) Design and freezing performance study of a CO2 plate freezer at -50°C evaporation temperature. International Institute of Refrigeration
  Academic chapter/article/Conference paper

2023

• Torp Dahl, Cecilie; Hafner, Armin; Ren, Shuai. (2023) Utilization of surplus heat from the organic dairy at Røros. NTNU
  Masters thesis
• Ren, Shuai; Ahrens, Marcel Ulrich; Hamid, Khalid; Tolstorebrov, Ignat; Hafner, Armin; Eikevik, Trygve Magne. (2023) PERFORMANCE MODELLING OF AMMONIA-WATER ABSORPTION-COMPRESSION HEAT PUMP FOR STEAM GENERATION IN FOOD PROCESSING . International Institute of Refrigeration
  Academic chapter/article/Conference paper
• Hamid, Khalid; Sajjad, Uzair; Ahrens, Marcel Ulrich; Ren, Shuai; Palanichamy, Ganesan; Tolstorebrov, Ignat. (2023) Potential evaluation of integrated high temperature heat pumps: A review of recent advances. Applied Thermal Engineering
  Academic article
• Selvnes, Håkon; Jenssen, Sigmund; Sevault, Alexis Gerard Edouard; Bengsch, Jan; Widell, Kristina Marianne Norne; Ahrens, Marcel Ulrich. (2023) Integrated CO2 refrigeration and heat pump system for a dairy plant: Energy analysis and potential for cold thermal energy storage. International Institute of Refrigeration
  Academic chapter/article/Conference paper
• Ren, Shuai; Ahrens, Marcel Ulrich; Hamid, Khalid; Tolstorebrov, Ignat; Hafner, Armin; Eikevik, Trygve Magne. (2023) Numerical investigation of an ammonia-water absorption-compression high-temperature heat pump for hot water and steam production in food processing. International Institute of Refrigeration
  Academic chapter/article/Conference paper

2022

• Ren, Shuai; Ahrens, Marcel Ulrich; Hafner, Armin; Widell, Kristina Norne. (2022) Performance evaluation of high-temperature heat pump systems for hot water and steam generation in food processing. International Institute of Refrigeration
  Academic chapter/article/Conference paper
• Selvnes, Håkon; Jenssen, Sigmund; Sevault, Alexis; Widell, Kristina Norne; Ahrens, Marcel Ulrich; Ren, Shuai. (2022) Integrated CO2 refrigeration and heat pump systems for dairies. International Institute of Refrigeration
  Academic chapter/article/Conference paper