Artificial intelligent modeling and optimization of pin-fin configuration on the thermal performance of two tubes inside phase change material for cooling of a solar panel using Ag-water nanofluid

Abstract

This paper performs a two phase numerical analysis on a solar thermal panel of dimensions 80 x 100 cm in the presence of Ag-water nanofluid flow. The nanofluid flows in two individual tubes beneath the panel, and there are some circular pin fins on the tubes. Tubes and pin fins under the panel are surrounded with a phase change material (PCM), paraffin wax. By increasing the length of pin fins from 1 to 7 cm, the volume fraction (VOF) of molten PCM, outlet nanofluid temperature (T-NF), and heat transfer coefficient (HTC) are examined from the transient state up to reaching the steady state. Utilizing a FEM based on a weak form, namely Galerkin, to find a numerical solution for mathematical modeling. Results of this study indicated that increasing the length of pin fins from 3 to 7 cm maximally increases the outlet nanofluid flow up to 2.11 degrees C. In the transient conditions, increasing the length of pin fins decreases the VOF of molten PCM. When the problem is evaluated in the transient conditions, increasing the length of pin fins decreases the mean temperature of the panel (T-PL), but in the steady-state conditions, the T-PL is the same for different lengths of pin fins. The lowest value of the HTC occurs for pin fins of length 3 cm, and in most cases, the average HTC is maximum for pin fins of length 1 cm.