Performance optimization of a solar adsorption chiller by dynamically adjusting the half-cycle time

Abstract

The half-cycle time effect on the performance of a solar single-stage dual-bed adsorption chiller, in Athens, Greece, in July, is investigated. The adsorption chiller coupled with the solar system is simulated, in real time, during the day for a) constant and b) adjusted half-cycle times and the system performance is monitored. In the former case, the half-cycle time is fixed, while in the latter one is dynamically adjusted according to the varying solar radiation intensity. Using a wide range of constant half-cycle times it is found that the maximum daily cooling capacity is obtained at some constant half-cycle time, which is larger than the optimum one of a single adsorption cycle. Similarly, using a wide range of adjusted half-cycle times, the one, providing the maximum cooling capacity is defined. The analysis is performed in a systematic manner through a proposed algebraic expression. It is found that the dynamically optimized adjusted half-cycle time operation mode provides about 12% higher daily and monthly cooling capacities than the corresponding maximum constant ones. This significant increase has been also confirmed for various incident solar radiation intensities. © 2020 Elsevier Ltd