Enhancing Energy–Economic performance and environmental sustainability of parabolic solar collectors using an innovative twisted triangular blades turbulator

Given the inherent thermal limitations of solar collectors, heat transfer enhancement strategies are essential to boost efficiency. To address this limitation, this study proposes a novel turbulator comprising twisted triangular blades mounted on support rings near the absorber tube wall. This configuration induces strong swirling and radial flow components, effectively disrupting the thermal boundary layer and enhancing hydrothermal, economic, and environmental performance. A three-dimensional numerical investigation using the RNG k–ε turbulence model is conducted for Reynolds numbers ranging from 5095 to 10190 to evaluate the effects of twist angle (90°–360°), blade length (5–20 mm), and blade count (3–6). Results indicate that, although increasing the twist angle, blade length, and blade number simultaneously enhances both heat transfer and pressure drop, the optimal hydrothermal and economic performance is achieved with a 180° twist angle, six blades, and a blade length of 15 mm. This design improves heat transfer by up to 223% compared with a plain tube, while attaining a performance evaluation criterion (PEC) of 2.24, a levelized cost of energy (LCOE) of 0.042 $/kWh, and a CO 2 emission reduction of 74.7 tons over the collector’s lifecycle.