# A case study assessing energy-exergy-economic (3E) performance in solar air heaters with different winglet geometries and air flow rates

## TL;DR

This study compares solar air heaters with different winglet designs and airflow rates to determine which performs best in terms of energy, environmental, and economic factors.

## Contribution

The study introduces a comparative 3E analysis of solar air heaters with inclined and sinusoidal winglet geometries under varying airflow rates.

## Key findings

- IWSAH achieves higher thermal efficiency (73.1%) compared to ISWSAH (68.8%).
- IWSAH reduces CO2 emissions by 54.1 kg annually compared to ISWSAH.
- IWSAH has a shorter energy payback time (1.33 years) than ISWSAH (1.62 years).

## Abstract

Solar air heater (SAH) research focuses on modifying absorber plates to enhance heat transfer through artificial roughness, fixing, and other cost-effective techniques. The objective of this investigation is to compare the energy, environmental, and economic (3E) performance of SAH with inclined triangular winglet (IWSAH) and sinusoidal winglet (ISWSAH) under diverse air flow rates (0.01 kg/s, 0.02 kg/s, and 0.03 kg/s). The results indicate that both winglet configurations exhibit improved performance, with IWSAH being considered the best. The output air temperature reaches a maximum of 82.7 °C at 0.01 kg/s flow rate in IWSAH and decreases as the airflow rate increases. With 1.12 times higher heat transfer coefficient, the average thermal efficiency of IWSAH reached 73.1% compared to 68.8% for ISWSAH. IWSAH achieves a net energy increase of approximately 4–6% more than ISWSAH. ISWSAH shows the maximum average heat loss when the airflow rate is at its minimum of 0.01 kg/s. A significant 52.3% gain in thermo-hydraulic efficiency occurs when the airflow rate is raised from 0.01 kg/s to 0.03 kg/s. This improvement is primarily due to the blower’s reduced power consumption in the IWSAH system, which was previously at 25.7%. IWSAH outperforms ISWSAH in both economic and environmental assessments. The economic and environmental analysis shows that the IWSAH system outperforms the ISWSAH system with a shorter energy payback time (1.33 vs. 1.62 years), higher energy production factor (2.96 vs. 2.71), better life cycle conversion efficiency (43.6% vs. 39.1%), and reduced emissions of CO2 (2147.2 vs. 2201.3 kg), NO (16.3 vs. 16.6 kg), and SO2 (6.7 vs. 6.9 kg), alongside lower annualized costs (₹3195.7 vs. ₹3268.5), demonstrating its superior economic and environmental viability.