Articles techniques et présentations

Preheating condition of salt storage vessel was analysed in COMSOL Multiphysics® to obtain the temperature distribution and time of heating and cooling cycle. Salt storage vessel is a stainless steel cylindrical vessel with surface heaters. The vessel is mounted vertically and insulated with insulating blanket all around. Preheating of vessel to 500 °C with argon gas inside was analysed in 2D-axisymmetric model. The study was carried out in two steps. A conjugate heat transfer - turbulent flow model with stationary study was solved to get the details of convective heat transfer in Argon gas inside the vessel. The results of this study was used as input to a time dependent study with equivalent thermal conductivity assumption for Argon domain, the interface used in this study is Heat Transfer in Solids. Time dependent study was used to evaluate the average argon temperature with time for a heating rate of 50 °C/hour at vessel wall. Heating of vessel wall is defined by a piece-wise linear function. Cooling of vessel from preheated condition is also modeled. Temperature boundary condition was disabled after heating cycle, the vessel gets cooled by natural convection from insulation surface.

Time dependent study was carried out for 24 h duration for both heating and cooling cycle. The result of the study provided the temperature distribution, convective flow pattern, preheating time and cooling time of salt storage vessel. Result shows that Argon gets heated to 500 °C in 12 hours and gets cooled to 180 °C in 24 hours duration. Results of equivalent conductivity model was compared with conjugate heat transfer model at selected wall temperature conditions to compare the results.