Table 5 Comparative summary of this work for the two literature applications
From: Application-based design of the Fresnel lens solar concentrator
Application | Solar welding | Solar stirling engine | ||
|---|---|---|---|---|
Romero et al. (2013) | This work | Aksoy and Karabulut (2013) | This work | |
Concentrator type | Reflective Parabolic trough | Refractive Spot Fresnel lens | Refractive Spot Fresnel lens | Refractive Spot Fresnel lens |
Receiver area | 176.7 mm2 | 176.7 mm2 | 78.5 cm2 | 78.5 cm2 |
Irradiance | 700 W/m2 | 700 W/m2 | 810 W/m2 | 810 W/m2 |
Concentrator Area | 1.767 m2 | 1.127 m2 | 1.400 m2 | 1.718 m2 |
Specific application parameters | Welding speed | Solar heat input to the Stirling engine | ||
0.3 mm/s | 0.167 mm/s | 1142 W | 1317.12 W | |
Total welding time | Receiver design | |||
200 s | 359 s | Cavity | Flat surface | |
Performance of this work for the referenced application | The lens has 36.2% smaller area with comparable welding quality (full penetration of molten state shown in Fig. 8) The acrylic lens is cheaper compared to the expensive parabolic trough furnace used in the literature The lens is lighter in weight and easier to install compared to the parabolic trough furnace used in the literature The slower welding speed of the lens system can be traded off by its cheaper and simpler design. System cost is a more pressing factor in many fabrication-level welding jobs than the welding time | Literature used a spot Fresnel lens, which is a good validation tool for this work’s optimization This work simplified the receiver design from a cavity to a flat surface This work considered the 1142 W of energy received (reported by the literature) to be energy utilized in the simplified design. This increased the solar energy required, thus the bigger lens size This work’s bigger lens supplied 15.34% more focal flux, and the engine reached steady operation without damaging the aluminum heater (Fig. 12b). Comparable to the operation achieved in the literature experiment The outer surface of the heat blanket remained at ambient temperature, same as in the literature experiment | ||