A review of solar powered absorption systems

For the last two centuries, fossil fuel has been considered and utilized as the main source of energy. However; the negative impacts of burning fossil fuel on the environment have forced the energy research continuity to seriously consider renewable sources of energy. Solar energy, in particular, has been the main focus in this regard because it is a source of clean energy and naturally available. Solar energy applications include solar photovoltaic and solar thermal. Solar thermal systems are used to power absorption refrigeration and air-conditioning systems. This study presents a review of recent published work in the field of solar powered absorption systems which utilize pairs of working fluid. The focus in this study is on solar powered absorption refrigeration systems, diffusion absorption systems, ejector based absorption systems, compression absorption systems and cogeneration/trigeneration absorption systems. The thermodynamic properties of most common working fluids as well as use of ternary mixtures in solar powered absorption systems have been reviewed in this study. The review indicates that along with aqua-ammonia and LiBr-water, there are certain other working fluids that have theoretically shown good performance such as lithium nitrate-ammonia, sodium thiocyanate-ammonia, TFE-TEGDME, methanol-TEDGME, monomethylamine-water and LiCl-water. It is also found that, for diffusion absorption systems, TFE-TEGDME working pair have theoretically shown good performance. The review also indicates that the ternary mixture of LiBr:CHO2K-water have shown good performance compared to other ternary mixtures.