Solar Regeneration Loop of a Liquid Desiccant Simulation

The following paper develops a simplified study of the conditioning of a 15m2 office located in Beirut during the month of July composed of a system using solar energy. This study was carried out thanks to the simulation of the different elements of the system. A desiccant liquid (CaCl2 in our case) crosses the office ceiling and allows both cooling and removal of moisture. This liquid allows absorption of water vapor at low temperatures and desorption at high temperatures. This solution is less corrosive and less expensive than the BrLi solution, another desiccant used in these systems that has better absorbency properties. In a cooling tower the solution evacuates the water vapor towards the ambient air. To obtain high temperatures solar panels are used and to cool it is used exchangers with the ground. The exchanger system allows heat transfer from the solar water circulating in the loop of the solar collector to the circuit of the desiccant liquid and the solution of this desiccant liquid to the water of the subsoil. A storage tank is also used to compensate for the drop in temperature at the outlet of the collector at the end of the afternoon. Two models of cooling tower have been tested: the one from an existing library that uses water only as crossing fluid, and Merkel theory; the second that we have computed and using the same theory but running offset the heat and moisture balance at each time step. The paper will first present the desiccant liquid and its properties; second the system sizing methodology; third the cooling tower modelling; and finally, the case study and the corresponding results. The parametric study is very useful for the validation of the adopted sizing. The study demonstrates a good ability of the solar regeneration loop to reduce the temperature and humidity of the office with the hot and humid climate of Beirut.