Thermodynamic optimization of a solar adsorption cooling system

A dynamic model for the simulation of a solar based adsorption chiller system for domestic air conditioning is presented. Solar irradiation is captured via an array of Parabolic Trough solar Collectors (PTCs), and stored via a properly sized hot water tank. A commercial silica gel adsorption machine drives the HVAC system. Care is given to the estimate of the available solar energy, and to the evaluation of the collector efficiency and its dependences on geometrical and surface properties, as well as on the direct solar radiation and ambient temperature. System performance at different locations is discussed, showing that in temperate climates (latitude ranging from 38° to 46°) it can offer a 4-6 kW cooling flow under most conditions, with 3-4 PTC panels. A tank size of around 1000 litres is enough for all of the investigated locations, and little advantage can be achieved by larger ones. The option of the combined use as summer chiller and winter heat pump, and direct heating via PTC hot water is discussed.