Adsorption cooling systems for heavy trucks A/C applications driven by exhaust and coolant waste heats

Water coolant and exhaust gases are the main waste heat sources of heavy trucks engine that can be used in driving adsorption cooling systems (ACS) for air conditioning and refrigeration demands. Due to the differences in heat source thermodynamic conditions, adsorbent materials and heating/cooling fluid flow loops of the exhaust and coolant driven ACS, identifying the higher performance system in terms of efficiency and cooling capacity under different operating conditions is not a trivial matter. In this study, considering an identical absorbent bed heat exchanger and ambient conditions, the performances of the coolant and exhaust driven systems with the working pairs of silica gel-water and zeolite13x-water, respectively, are investigated by means of a detailed numerical model. Parametric studies show that the exhaust driven system at different operating conditions is more capable of meeting the cooling demands in comparison with the coolant driven system at its practical operating conditions. In addition, the evaluation of both systems performance at higher ambient temperatures indicates that the increase in ambient temperature leads to an almost linear performance drop in both systems, however, that is more considerable in the coolant driven ACS. Finally, the design of both systems and their challenges are briefly discussed.