Abstract
Air heat exchanger for reaching cold air has been suggested in current article including sinusoidal containers filled with PCM. The type of paraffin (RT25) was selected according to summer temperature and TiO2 nano-sized materials have been dispersed in to paraffin. Hot air with T-in & nbsp;= 35 ?& nbsp;and Re=6000 enters the duct and goes through the air passages among the containers. At start of process, temperature of domain is 20 ?& nbsp;and PCM become warmer and its temperature reaches to 25 ?& nbsp;then it starts to convert to liquid. The regimes of flow inside the paraffin and air zones are laminar and turbulent. Finite volume method with K-epsilon approach and implicit technique for transient terms has been incorporated considering structure form of grid. With dispersing the TiO2 nanoparticles, the required time for melting reduces about 4.59% and 4.67% when b = 7.5 and 12.5 mm. This promising effect of nanomaterial on charging rate is mainly relevant to augmentation of conductivity. If the distance between the PCM tanks (b) augments, hot air can move easier along the passages and charging rate enhances about 45.26%. When b = 12.5 and & nbsp;phi & nbsp;= 0.04, the minimum needed time for melting occurs and charging completed after 5.47 hr.