Boiling process assessment for absorption heat pumps: A review

Abstract Absorption technology becomes an attractive option for cooling or heating when driven by solar thermal energy, residual heat from different processes, or geothermal energy. Further development of this technology could help to cover current cooling or heating requirements and have a much lower impact on the environment than mechanical compression cooling and heat pumps systems. Moreover, the rising cost of electrical energy added to the issue of climate change are reasons to move towards the development of environmental and sustainable energy technologies. The desorbers are key components of absorption heat pump technologies. Studies in the open literature on desorbers show advances in new design concepts to enhance heat and mass transfer with different working fluids. Therefore, the objective of this review is to identify, summarise, and discuss the experimental studies that deal with the boiling process in desorbers and boiling correlations specifically for use in absorption heat pump technologies. It includes a comprehensive scrutiny on the boiling phenomenon in pool desorbers, falling-film desorbers, and forced flow desorbers for conventional and promising working fluids, and details the experimental techniques and the latest advances in desorber design concepts. Finally, the review contains proposals for future studies to be carried out so as to contribute to the further development of absorption heat pump technologies.