Modeling investigation for energy storage system including mixture of paraffin and ZnO nano-powders considering porous media

Abstract

In this work, air conditioning unit with involve of porous media has been presented. The duct has several five-lobed cylinders containing the paraffin (RT27) and for augmenting the conductivity of such material, it was mixed with nano-sized particles of ZnO. To include the related terms of porous media, wiremesh approach was applied and turbulent regime for air zone was considered. Owing to solar irradiation, air becomes warmer up to T = 311.15K outside the duct and with entering within the duct makes paraffin to convert to liquid. So, not only the solar energy can be stored, but also the needed cool air inside the building can be provided. Mixing nanoparticles with paraffin leads to higher level of conduction which decline the required time for full melting about 5.22% when Re = 7000, γ = 0.95. With utilizing porous media, the needed time will be decreased about 37.15% when Re = 7000, φ = 0.035. As power of blower augments, the period of melting decreases around 41.77% when γ = 0.95, φ = 0.035. Among the scrutinized cases, the minimum required time for achieving full melting is 7985s which can be attained if γ = 0.95, φ = 0.035, Re = 7000.