|Address:||G5703, 5/F, Yeung Kin Man Academic Building (YEUNG),
City University of Hong Kong,
Tat Chee Avenue, Kowloon, Hong Kong SAR
CREVER-Group of Applied Thermal Engineering, Universitat Rovira i Virgili, Av. Països Catalans 26, Tarragona, Spain
High-temperature heat pumps (HTHPs) are regarded as a viable and attractive solution to upgrade low-to-medium temperature industrial waste/excess heat to a useful temperature level for many industrial processes. It can be implemented in a wide range of industries as heat recovery solutions, including beverage, chemical, food, paper, leather, and textile industries. Furthermore, there are ongoing research and development activities to fully utilize the heat recovery potential of HTHPs at a heat supply temperature above 90°C.
This lecture reviews the current status and new developments on high-temperature heat pumps with heat supply temperatures above 90°C for industrial applications. Besides the vapor compression heat pumps, the focus of this work is on absorption heat pumps, absorption heat transformers and compression-resorption heat pumps. Moreover, recent advancements in compressor technologies and working fluids for high-temperature vapor compression heat pumps are also highlighted. A few manufacturers are available in the high-temperature heat pump market segment that can supply single-stage LiBr/water absorption heat transformer and ammonia/water compression-resorption heat pump technologies. The heating capacity range of the commercial LiBr/water heat transformers is from 150 to 10,000 kW, while the thermal COP is between 0.45 and 0.50 at temperature lifts of up to 50 K. The commercially available compression-resorption technology delivers heat up to 120°C, while the obtained electrical COPs are about 6.1 (at 22 K lift), 4.3 (at 65 K lift) and 2.4 (at 75 K lift). Many theoretical and experimental studies have been carried out in order to extend the limit of achievable temperature lift and COP of high-temperature heat pumps.
There is a strong potential for absorption heat transformers and compression/resorption heat pump technologies for high-temperature lift and heat supply temperature above 160°C, which is the current limit for vapor compression heat pump technology. Therefore, in order to capitalize these potentials, future research and development activities are mainly directed towards the following areas: (i)-on working fluid pairs to alleviate the drawbacks of the conventional working fluid mixtures, (ii) – system components size reduction so that the size and capital cost of the heat pump reduced, and (iii) – system (cycle) configurations to obtain higher temperature lift than the single-stage AHT, while maintaining the COP or with reasonable lower COP values.
Prof. Alberto Coronas obtained his B.Sc. and M.Sc. degrees from Barcelona University (Barcelona, Spain) in 1974 and 1979, respectively. He received his Ph.D. in 1983 from the Barcelona University (Barcelona, Spain). He started his research into absorption refrigeration and heat pumps during a postdoctoral stay under the supervision of Prof. Robert Bugarel in the Ecole Nationale Supérieure d’Ingénieurs en Génie Chimique (Toulouse, France) in 1985. He worked as lecturer at the Chemistry Faculty (Tarragona) of the Barcelona University until 1994. He worked as lecturer at the Mechanical Engineering Department of Rovira i Virgili University until 2001 and since then as full professor on Thermal Engineering. In the period 2008-15, he was the academic coordinator of the postgraduate program on Air Conditioning Technologies and Energy Efficiency in Buildings, and from 2009 coordinates at the Rovira i Virgili University the master and doctorate program in Thermodynamics Engineering of Fluids. He is the head and founder of the Research Group on Applied Thermal Engineering (CREVER) since 1994.
His research activity covers the field of absorption technology for industrial refrigeration, heat pumps and chillers, heat and mass transfer in sorption processes and thermophysical properties of new working mixtures, and polygeneration technologies. He has supervised more than 30 Ph.D. theses and published around 250-refereed technical publications. He has participated and coordinated many national and international projects related with the development of absorption chillers and the energy efficiency monitoring and analysis of cooling plants. He has a very good knowledge on cooling applications in industries (agrofood, petrochemicals, plastics manufacturing, etc) and the recent developments in the cooling market from new systems to advances in existing technologies. The research group is also internationally recognized by its knowledge on the development of new configurations of advanced absorption chillers using conventional and new working fluids.
Prof. Coronas has served on many scientific committees of such international conferences as International Sorption Heat Pump Conference, Solar Air Conditioning Conference, International Polygeneration Conference (2007, 2011, 2015, 2017, and 2019), IMPRES (2013, 2017), CYTEF, Gustav Lorentzen Conferences on Natural refrigerants etc.
He served as managing Guest Editor for Applied Thermal Engineering (Elsevier) in 2012, 2016 and 2018 and for the Science and Technology for the Built Environment (CRC Press Group) in 2015. Professor Coronas served as a vice-president of Commission E2 Heat Pumps, energy recovery of the International Institute of Refrigeration IIR between 2012 and 2015 before becoming President. 6.735) etc.