Efficiency Enhancement in Double-Pass Perforated Glazed Solar Air Heaters with Porous Beds: Taguchi-Artificial Neural Network Optimization and Cost–Benefit Analysis

Roozbeh Vaziri,Mohsen Sharifpur,Mohammad Hossein Ahmadi,Rani Taher,Akeem Adeyemi Oladipo,Alibek Issakhov

doi:10.3390/su132111654

Abstract

Analyzing the combination of involving parameters impacting the efficiency of solar air heaters is an attractive research areas. In this study, cost-effective double-pass perforated glazed solar air heaters (SAHs) packed with wire mesh layers (DPGSAHM), and iron wools (DPGSAHI) were fabricated, tested and experimentally enhanced under different operating conditions. Forty-eight iron pieces of wool and fifteen steel wire mesh layers were located between the external plexiglass and internal glass, which is utilized as an absorber plate. The experimental outcomes show that the thermal efficiency enhances as the air mass flow rate increases for the range of 0.014–0.033 kg/s. The highest thermal efficiency gained by utilizing the hybrid optimized DPGSAHM and DPGSAHI was 94 and 97%, respectively. The exergy efficiency and temperature difference (∆T) indicated an inverse relationship with mass flow rate. When the DPGSAHM and DPGSAHI were optimized by the hybrid procedure and employing the Taguchi-artificial neural network, enhancements in the thermal efficiency by 1.25% and in exergy efficiency by 2.4% were delivered. The results show the average cost per kW (USD 0.028) of useful heat gained by the DPGSAHM and DPGSAHI to be relatively higher than some double-pass SAHs reported in the literature.

Highlights

The conventional solar air heaters (SAHs) consist of a solar radiation absorber plate and a parallel plate below through which the inlet air is heated and obtained hot air utilized for various applications, such as greenhouse heating, curing of concrete building components and seasoning of timber [1,2,3]
The L8 orthogonal design described by the Taguchi method was used for the optimization of the configuration of the SAH packed with iron wools (DPGSAHI) and mesh layers (DPGSAHM)
The as-fabricated SAHs exhibited a decrease in the thermal efficiency as the mass flow rate was decreased from 0.033 kg/s to 0.014 kg/s

Summary

Introduction

Concerted interests have been directed toward renewable energy conversion systems due to their potential in providing a sustainable future. Solar collectors (water/air) are widely applied in various thermal equipment for the optimal and efficient utilization of solar energy. The conventional solar air heaters (SAHs) consist of a solar radiation absorber plate and a parallel plate below through which the inlet air is heated and obtained hot air utilized for various applications, such as greenhouse heating, curing of concrete building components and seasoning of timber [1,2,3]. The conventional SAHs are cheap, simple in design and require little maintenance [4]

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Conclusion