Thermal Performance of a Heated Plate With Open-Channel Infrared Radiation Shields

Abstract

The heat transfer associated with various radiation shield designs has been investigated. Mathematical models were used to characterize the thermal performance of a vertical heated plate, with and without a continuous radiation shield, under various environmental conditions. Predictions were compared with laboratory results taken under simulated solar radiation and wind conditions. Measurements of channel temperature and velocity distributions were made to help characterize the thermal performance. Plate temperature predictions from the model, using measured power input, ambient temperature, and channel air velocities, gave results which were within 5° C of the experimental values. The infrared energy emitted in the 8—14μ band was calculated as a function of the measured plate and/or screen temperatures for each set of experimental conditions. Double layers of incised radiation shields were found to have the lowest effective infrared energy emission. For the two screen incision sizes tested, the size of the incision did not significantly influence the temperature and velocity profiles or the amount of radiant energy emitted from the plate/screen combination.