Direct cooling/heating approach for solar-driven vapour absorption cooling system

The conventional approach to discharge the heat from an absorber to the ground is through a second circulation loop. The same method is also used to covey the heat from the solar collector to the generator when using solar collector to supply the heat to the vapour absorption system. This indirect approach adds extra temperature difference in the heat transfer processes, which could affect the system’s overall performance, particularly; when the system is driven by a low temperature heat source. This paper reports a theoretical investigation of a direct cooling approach in which the absorbent solution is directly cooled and heated in the ground and the solar collector, respectively. The theoretical analysis showed that the directly cooled ground-loop absorber would incur a higher-pressure loss compared to a configuration using a conventional absorber plus a second circulation loop. However, the overall performance is improved as a result of the elimination of the second circulation loops.