Application of Aluminium Oxide–Water Nanofluids to Augment the Performance of Shallow Pond: a Numerical Study

A solar pond is a thermal energy storage device. It has three different layers of saltwater gradients. The bottom layer of the solar pond has higher salt intensity, and it is used to store solar energy. By utilizing this layer, the solar pond can be used for heat storage applications. The usage of nanomaterial in the bottom layer of the solar pond improves the energy storage, fluid’s thermal conductivity, and heat capacity. The numerical study of a single glazing solar pond with nanofluids is discussed in the present work. The investigation is made from 0 to 0.1 fraction of volume concentration of aluminium oxide–water nanofluids in the conventional shallow type solar pond. The conventional setup of the solar pond is implemented to validate the numerical results. The zigzag copper coil acts as a heat exchanger, and it is used to extract the heat from the solar pond. In conventional one, water is used as a working fluid in the heat exchanger. At that moment, the maximum outlet temperature of the heat exchanger is 331.54 K, and it can be utilized for various applications. If the Al 2 O 3 nanofluids are filled in the bottom layer of the solar pond instead of saltwater gradients, the maximum outlet temperature of the heat exchanger is enhanced to 335.64 K. If the same setup is implemented with the evacuated tubes, the outlet temperature of the heat exchanger is further enhanced to 345.52 K. The overall efficiency of the salt gradient solar pond is also improved from 21.82 to 27.55% on using nanofluids at 0.1 volume fraction. The entire setup is simulated using ANSYS Fluent, and the numerical analysis is carried out. The effect of evacuated tubes and fins on the solar pond performance is investigated, and the results show the present work’s superiority compared with the conventional one.