Engineering and Architecture
Mahmoud Bourouis / Jose Miguel Corberan
firstname.lastname@example.org / email@example.com
Universitat Rovira i Virgili; Universitat Politecnica de Valencia
Theoretical and experimental investigation on sorption processes with water/LiBr mixtures in advanced heat and mass exchangers for absorption heat pumps
Absorption heat pumps (AHPs) are recognized for their energy-saving potential when they are driven by low-grade heat or renewable heat sources. AHPs are only present in the space cooling market and cannot produce heating due to the limitations of its main working fluid, water/LiBr. This fluid mixture has very good thermophysical properties, but it also suffers from certain problems such as crystallization of the LiBr, corrosivity, etc.
The absorber and desorber are the most important components in AHPs playing a critical role in the overall performance, physical size, and capital cost of the system. Both heat and mass transfers take place simultaneously in these components. The design and configurations of the absorber and desorber significantly influence their performance. Therefore, there is a need to improve heat and mass transfer processes in these components in order to contribute to their technological development, overcome the barriers that limit their competitiveness and diffusion, and assist in meeting the growing demand for energy and current climate change challenges. This has resulted in an increasing interest in heat and mass transfer enhancement and miniaturization of the main components of these systems using passive techniques such as advanced heat exchangers, membrane contactors, additives, and nanofluids.
Use of asymmetric plate heat exchangers and membrane contactors in AHPs are considered as alternative technologies for minimizing the size of this equipment and extending their operation range. The performance of heat and mass transfer in the components is significantly improved because of better wettability and mixing at low solution flow rates and higher area to volume ratio available. Few investigations are available in the open literature on the use these components in AHPs. These have demonstrated that; (i) there is still a lack of experimental information on the performance of these components, (ii) there is a lack of comprehensive evaluation and design criteria for the definition of the geometrical and flow characteristics of absorbers and desorbers based on these technologies to increase the absorption and desorption rates.
According to the analysis presented above, the main objective of the research project is the development of advanced heat and mass exchangers for the absorber and desorber of new water-LiBr Absorption Heat Pumps for space heating and cooling applications in order to be compact and competitive from energy, environmental and economic perspectives with respect to conventional systems.
To achieve the main goal, the absorption and desorption processes with water/LiBr based solutions will be studied for a selected technology to determine the wettability behavior, the heat and mass transfer coefficients and other efficiency criteria under the working conditions of Absoprtion Heat pumps used for both heating and cooling mode. An experimental set-up will be built and equipped with the necessary measurements sensors in order to collect redundant data that allow to examine the quality of the database and if necessary to apply a data reconciliation method. Results of the experimental studies will be used to develop semi-empirical models of the heat and mass transfer coefficients that will be implemented in a simulation tool.
Ethics: This project does not involve ethical aspects.
Workplace location: Campus Sescelades, Tarragona
37.5 hours a week
15 March 2021
|This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 945413|