Analysis of Superheater Tubes with Mutual Irradiation as Applied to a Solar Receiver Steam Generator
N. Lemcoff1 S. Wyatt2
1Rensselaer Polytechnic Institute, Hartford, CT, USA
2Alstom Power, Windsor, CT, USA
The objective of this paper is to analyze the temperature variations within a superheater tube of a solar receiver steam generator. The tube is heated by concentrated, collimated solar irradiation with major cooling by an internal steam flow. The influence of heat loss by radiation, internal convection, and conduction are considered. Analytical models are obtained for an isolated tube, and the significance of mutual irradiation of adjacent tubes is studied using COMSOL Multiphysics. The tubes outer surface maximum temperature decreases significantly as the internal heat transfer coefficient increases. Also, the radiosity decreases as the emissivity of the radiating surfaces increases. The results obtained help understand the effect of system parameters and can lead to an optimized steam generator design.