Influence of Al2O3 nano powder on performance of solar collector considering turbulent flow

Abstract

Current article deals with investigation of exergy drop within a tube enhanced by tapes. Hydrothermal treatment and exergy behavior of carrier fluid were scrutinized to find the best design regarding to greater available energy. Second law efficiency (ηII) and exergy loss (Xd) are main goal functions and simulations were reported for various number of tapes (TTn) and Reynolds number (Re). As tapes installed in the pipe, cross section area decreases and significant increment occurs in swirl flow. Intensification of rotational flow with rise of TTn makes higher disruption of flow and resistance enhances. The greatest impacts of Re and TTn on exergy ratio are reduction about 24.45% and 45.45%, respectively. Second law efficiency (ηII) for TTn = 3 is 2.04 times greater than that of TTn = 1 when Re = 4000. If Re augments, ηIIaugments about 92.86% when TTn = 4. Utilize of turbulator led to the greatest second law efficiency factor up to 0.78 when TTn = 4 when Re = 20000. Exergy drop becomes 2.22 times smaller if Re augments when TTn = 1. Value of exergy drop for Re = 4000 is 2.75 times higher than that of Re = 20,000 when TTn = 4. When Re = 20,000, growth of number of tapes to 3 makes Xd to reduce about 34.54%. In view of energy saving, it is better to install the tapes at low Re while it possess higher exergy drop. Influence of Re on temperature of absorber is higher than that of nanomaterial flow. At TTn = 2, temperature of absorber declines about 4.26% with increase of Re while nanomaterial temperature reduces about 0.43%.