PCM in the heat rejection loops of absorption chillers. A feasibility study for the residential sector in Spain

This study investigates the integration of phase change materials (PCMs) in the heat rejection loops of absorption solar cooling systems for residential applications in Spain. The feasibility of replacing the open wet tower by an alternative air-cooled system based on a combination of dry-coolers and a thermal energy storage (TES) with PCM inside (TESpcm) has been evaluated in terms of the total cooling energy produced and the system efficiency. TRNSYS® parametric simulations of two configurations have been conducted between the months of June and September. Their performance has been characterized and their advantages and disadvantages have been summarized. The results indicate that the alternative heat rejection loop with a TESpcm of 1 m3 can improve the mean overall system performance coefficient in locations with temperate and humid summers by almost one unit, although different degrees of the deterioration of the mean chiller's performance coefficient (values between 7 and 13%) and a reduction in the total cooling energy produced in the evaporator (21–38%) are inevitable. The study concludes with some suggestions for future work.