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Session 10a: Management of heat in buildings and processes
Time:
Tuesday, 12/Aug/2025:
4:00pm - 5:00pm
Session Topics:
Management of heat in buildings and processes, New technologies that avoid the use or global warming refrigerants
Presentations
4:00pm - 4:20pm ID: 1108 / Session 10a: 1 Full Paper Topics: Management of heat in buildings and processes, New technologies that avoid the use or global warming refrigerants Keywords: High Temperature Heat Pump, Compressor Assisted, Absorption Heat Transformer, Ammonia absorption, Waste Heat Recovery
Numerical Study of an Ammonia-Water Absorption Heat Transformer to Upgrade Low-temperature Industrial Waste Heat in Regard to Rising Ambient Temperature
Romain Collignon, Hélène Demasles, Hai Trieu Phan
Univ. Grenoble Alpes, CEA, Liten, Campus Ines, 73375 Le Bourget du Lac, France
Multiple industries require heat at a high temperature while dissipating heat at moderate to low temperature. In this context, sorption systems are a promising solution able to valorise waste energy at a low electricity cost, up to ten times less electrical power compared to an equivalent vapor compression heat pump. Specifically, Absorption Heat Transformer (AHT) are a type of absorption machine able to recover low-level waste heat () in order to provide higher-level heat (). In this study, a single stage AHT based on the NH3/H2O mixture is developed. Results enable to evaluate the performances of the AHT fed by industrial waste heat and cooled by ambient air and show that the standard architecture is limited by summer operating conditions. The influence of both the waste heat and ambient air temperatures are evaluated and the effect of the inclusion of a compressor in the cycle is discussed.
4:20pm - 4:40pm ID: 1168 / Session 10a: 2 Full Paper Topics: Management of heat in buildings and processes, Working fluids and rising temperatures, Successful cooling in extreme temperatures, New technologies that avoid the use or global warming refrigerants Keywords: R744, Heat pump, Chiller, Domestic hot water, Hotel energy systems
R744-Based Integrated Heat Pump and Chiller System for Hotels in Tropical Climates
1Norwegian University of Science and Technology, Norway; 2Medors Renewable Energy Pvt Ltd, New Delhi, India
Hotels in India typically rely on synthetic refrigerant-based chillers for space cooling and diesel-fired water heaters for hot water production—both energy-intensive solutions that contribute significantly to global warming. Transitioning to natural refrigerants like CO2 is a promising alternative, but this shift faces several challenges in India, including high ambient temperatures, limited technical expertise, resistance to adopting new technologies, and a shortage of skilled professionals. Demonstrating the real-world performance of such systems is essential to overcoming these barriers. This paper presents and discusses the first set of field data from a CO2 heat pump recently implemented in a hotel located in a tropical region of India. The system successfully met its design goals, producing hot water at 80 °C while simultaneously providing chilled glycol-water at 2 °C. The results indicate that CO2 based systems can effectively meet both heating and cooling demands in warmer climates, offering a sustainable alternative for the hospitality industry.
