Thermomechanical interaction of particle bed-structural wall in a layered configuration Part II: Combined effects of bed thermal expansions and coolant pressure

Abstract

Abstract In Part I of this study, a model representing the thermomechanical response of a particle bed-structural wall system in a layered configuration, subjected to both a bed temperature rise and an external coolant pressure, was presented. The results of a parametric study, based on the developed model, on the effect of the bed thermal expansions alone on a beryllium particle bed-stainless steel system were also presented. In this paper we present Part II of the study. The thermomechanical behaviour of a beryllium particle bed-stainless steel structural wall system subjected to (1) pure external coolant pressure and (2) a combination of bed temperture rise and coolant pressure is considered. Longitudinal variations in the thermomechanical properties of the particle bed-structural wall are studied. Results show that the bed temperture rises in the range 100–400°C and coolant pressures in the range 1–2 MPa, depending on the stiffness of the structural walls, could cause non-uniform effective thermal properties through the particle bed and increase the bed effective thermal conductivity by a factor of 2–5 and the bed-wall interface thermal conductance coefficient by even larger factors. The effect of increased wall stiffness is to reduce the influence of the external coolant pressure and to increase the influence of thermal expansions on the particle bed thermomechanical response.