Active cooling of photovoltaic (PV) cell by acoustic excitation in single-dimpled internal channel

Abstract

Solar energy is widely advocated by many countries which is the most popular renewable energy. To get the higher efficiency of the photovoltaic (PV) cell, enhancing cooling performance of the coolant channel is important. In this study, the effect of acoustic excitation was analyzed to enhance the cooling performance of internal channel imprinted with single-dimple for solar PV cell system. Various acoustic-excitation frequencies were compared for the optimized cooling performance of dimple-imprint channel. All experiments were conducted under laminar-flow conditions. The experiments indicated that a Strouhal number of 1.1 corresponding to a similar frequency of the vortex shedding within the dimple cavity was most-effective to enhance cooling performance. By analyzing the local heat/mass transfer distributions, the effect of acoustic excitation can be clearly noticed within the dimple cavity where vorticities formed. In the aft-plateau region, heat/mass transfer gradually decreased and the effect of acoustic excitation was minimal. Overall, the area-averaged heat/mass transfer was enhanced by 68% at St = 1.1. Furthermore, when the acoustic excitation was adopted, the area-averaged heat/mass transfer was enhanced by 26–35% in other frequency cases. It was concluded that an appropriate acoustic-excitation frequency could effectively improve the cooling performance of a single-dimple imprinted channel. In the end, the efficiency of PV cell will be enhanced by adopting the acoustic-excitation with dimple imprint cooling channel.