Energy-based performance analysis of a double pass solar air collector integrated to triangular shaped fins

Maytham H Machi,Maytham A Al-Neama,I Farkas,J Buzás

doi:10.1007/s40095-021-00422-z

Abstract

In this paper, the performance of a double pass solar air collector with triangular integrated fins was investigated experimentally at Hungarian University of Agriculture and Life Sciences in Gödöllő, Hungary. The focus of this research is on energy-based performance evaluation. The thermal efficiency of the collector has been compared by testing two collectors that had the same design, with and without fins. The effect of the collector's air mass flow rate on thermal performance was investigated under various environmental situations. The results revealed that the temperature difference is always higher through the finned collector and the higher variation temperature between the inlet and outlet temperature leads to higher useful heat. The daily thermal efficiency of the finned collector was 56.57%, 59.41%, and 61.42%, while for the un-finned collector was 51.04%, 53.28%, and 57.08% for the mass flow rate 0.0081, 0.0101, and 0.0121 kg/s. The finned double pass solar air collector improved the thermal efficiency by 4.3–6.1% over the un-finned one. The efficiency of the finned collector is always higher than the un-finned one regardless of the mass flow rate. The presence of the fins to the top air channels significantly increases collector efficiency, owing to the increased absorbing surface area, which is responsible for increasing the internal thermal convective exchanges. Moreover, it creates a turbulence airflow, meaning that the air will be in good contact with the absorber plate and penetrate all regions, reducing the dead zones contributing to increased heat transfer.

Highlights

The incredibly increasing world population gives rise to increases in energy demands, which leads to an increase in the usage of conventional fuels
Solar energy can be utilized by using several technologies that work as a converter through converting the solar radiation to usable electricity or heat using photovoltaic (PV) and thermal systems
The findings revealed that the outlet temperature is strongly influenced by solar radiation intensity and has an inverse relationship with air mass flow rate, which increases as the mass flow rate decrease and vice versa

Summary

Introduction

The incredibly increasing world population gives rise to increases in energy demands, which leads to an increase in the usage of conventional fuels. The limited sources of traditional fuels and environmental protection issues, and global warming, are becoming a pressing problem that needs to be outlined These concerns drew the attention of the researchers to find renewable resources considered a promising solution to global warming and a way for keeping sustainable growth for human beings [1]. Solar energy can be utilized by using several technologies that work as a converter through converting the solar radiation to usable electricity or heat using photovoltaic (PV) and thermal systems. The primary device for collecting solar energy, known as a solar energy collector, should be present in any solar thermal system It works as a unique heat exchanger that converts solar radiation energy to heat energy stored inside a transport fluid (air, water, or oil) [3]. One of the most potential solar energy applications is the supply of hot air through the solar air collector to dry agricultural or marine products

Methods

Results

Conclusion