Thermal Analysis of a Solar External Receiver Tube with a Novel Component of Guide Vanes

The heat transfer performance of a solar external receiver tube with guide vanes was numerically studied under non-uniform heat flux conditions. Models of the smooth tube and the tube with guide vanes were built. The distributions of the temperature, velocity, turbulence intensity, and Nu predicted by these two models were compared to investigate the heat transfer enhancement and the mixing effect of the guide vanes. The effect of the Re and the alpha on the heat transfer enhancement was also studied. The results show that the guide vanes form spiraling flows, reduce the maximum tube and molten salt temperatures, and improve the heat transfer. In addition, a more uniform temperature distribution is achieved compared to the smooth tube, allowing the molten salt to work safely under higher heat flux conditions in the receiver tube with guide vanes. It was observed that a larger Re enhances the heat transfer on the tube wall and achieves a longer effective distance of enhanced heat transfer in the downstream region, while the spiraling flow, the heat transfer enhancement, and the mixing are stronger for a larger alpha.

Automated summary

The heat transfer performance of a solar external receiver tube with guide vanes was studied numerically under non-uniform heat flux conditions. The guide vanes form spiraling flows, reducing maximum temperatures and improving heat transfer. A more uniform temperature distribution is achieved compared to a smooth tube, allowing safe operation under higher heat flux conditions. Larger Reynolds numbers enhance heat transfer on the tube wall and achieve longer effective distances of enhanced heat transfer, while stronger spiraling flow, heat transfer enhancement, and mixing effects are observed for larger alphas.