Performance analysis of a waste heat recovery solar chimney for nocturnal use

Abstract

Solar chimney is one of the best ways to produce artificial wind to drive wind turbines. But the main problem associated with is that it’s dependence on solar energy and hence can’t be used during night times. The objective of the present work is to modify the existing model; so that it can be used for the generation of power even in nocturnal and cloudy conditions. There are many ways to recover waste heat from different industries, but solar chimney can give one of the leading possible ways to recover it. Waste heat can be used to heat the base or absorber of the solar chimney’s collector; or it can be used to heat the air flowing inside the chimney. Ansys 2019 R1 has been used for the Computational Fluid Dynamics (CFD) validation and analysis of the solar chimney with heat recovery heat exchanger. A heat exchanger (HE) plate of aluminium alloy has been used with syltherm-800 as heat transfer fluid (HTF), and exchanging heat with the air inside the chimney near its base. Effect of different parameters like HTF inlet temperature, mass flow rate of HTF, ambient temperature of air, and diameter of heat exchanger plate on the performance of solar collector of chimney has been analysed. Also, the maximum conversion efficiency of about 5% is achieved, which is more in comparison to solar chimney operating at normal day conditions. Limitation of the present work is related to the storage of heat during day time or there should be continuous supply of waste heat during chimney operations. In this paper, authors have proposed a CFD method for the modification and improvement of solar chimney in Manzanares (Spain) with a waste heat recovery heat exchanger for nocturnal use.