ENERGY EFFICIENCY ENHANCEMENT FOR SOLAR AIR HEATER BY USING CORRUGATED RIBS WITH VARIABLE HEAT FLUX FOR LAMINAR FLOW

An experimental analysis is conducted to determine how corrugated absorbent tubes affect the functionality of a collector with a parabolic trough (PTC). Nine distinct helically corrugated absorbent pipes were employed for this particular purpose. Using ASHRAE standard 93 (2010) as a guide, the effects of pitch size and irregularity height upon PTC effectiveness were investigated. The range of the Re was 5000–10,000. The findings show the thermal efficiency and heat transmission. With corrugated pipes, the typical heat transfer rates rose from 85.7 to 107.2%, correlated with the pitch's percentage and irregularity height. When it equals 3 mm & 1.5 mm, respectively, the thermal efficiency reaches a maximum level of around 2.29, for both the 3 or 1.5-mm pitch size and roughness elevation respectively. In wavy pipes, the average coefficient of friction rises by 1.25 – 1.85 at certain times. Additionally, applying the most effective fit for the sequence of measurements, the changes with the Nu, as well as friction factor with pitch-to-diameter ratio, roughness, Pr, and Re, are provided as relationships.