Effect of a thermal sleeve on the temperature non-uniformity of an annuli under solar irradiation

Abstract

Abstract Heat transfer of an annuli under solar irradiation or forced convection is numerically studied. A conjugate heat transfer model, which includes conduction, natural convection and surface radiation, is developed and solved by finite volume method. The effects of the thickness of the inner cylinder on the temperature contours are analyzed. Results show that the temperature in the domain is non-uniform when it is exposed directly to the sun radiation, and is almost uniform when a thermal sleeve is used. Neglecting the surface radiation between the barrel wall and sleeve wall will underestimate the temperature of the annuli. During continuous firing conditions, natural convection in the air gap shows chaotic behavior.