Thermal and hydrodynamic characteristics of Therminol VP-1 oil flow across perforated conical hollow turbulence promoter in Scheffler dish receiver tube.

Abstract

This study examines the thermal and hydrodynamic characteristics of Therminol VP-1 oil flow through perforated conical hollow-type turbulence promoters installed in a solar Scheffler dish collector receiver tube, utilizing computational fluid dynamics (CFD) analysis. The research examines these configurations using the RNG k-ε turbulence model with conventional wall functions. Simulations are conducted at Reynolds numbers ranging from 3000 to 15,000, with relative perforated conical hollow-type turbulence promoters ratios (Per_ID/Per_OD) varying from 2.11 to 2.33, relative turbulence promoter pitch (P_TP/D_tube) spanning from 2.25 to 3.08, and a relative turbulence promoter diameter (DB_inlet/DB_outlet) is constant at 2.0 to evaluate heat transfer and friction factor characteristics. An experimental analysis has been conducted on a solar Scheffler dish collector receiver using a plain tube with Therminol VP-1 as the heat transfer fluid to validate the CFD results for the current study. Moreover, the CFD results have been verified through a comparison with a conventional surface solar Scheffler dish collector receiver tube utilizing Therminol VP-1 as the heat transfer fluid. This comparison encompassed theoretical relationships and empirical data pertaining to the Nusselt number and friction factor. The CFD results for the plain surface solar receiver tube demonstrated important alignment with experimental data and theoretical predictions based on the standard Dittus and Blasius equations, exhibiting reasonable deviation throughout the analyzed range. Overall, the CFD results demonstrate that Therminol VP-1, combined with perforated conical hollow-type turbulence promoters, improves thermal efficiency, providing an effective approach for enhancing Scheffler dish receiver tubes while reducing excess pressure losses. According to thermal and hydraulic performance data, hollow-type conical turbulence promoters enhanced heat transfer, with the best performance achieved at Per_ID/Per_OD of 2.25 and a (P_TP/D_tube) of 2.83.