Numerical Analysis of Passive Heavy Concrete Wall Cool Discharge Performance

Abstract

Focusing on the concrete structure with rib-steel fin to enhance heat transfer, the impacts of structural feature (height of rib), thermal parameter (heat transfer coefficient), and indoor temperature set point (initial temperature of the wall) are studied by means of CFD simulation. The results indicate that the initial temperature of the wall shows the greatest effect, followed by the rib height dimensions and heat transfer coefficient with minimal impact on the cool discharged value from the heavy wall within 72 h. From the aspect of time response of the wall cool discharge, heat transfer coefficient of the wall shows the greatest impact on the time constant of the cool discharge process, followed by the rib height, and the initial temperature of the wall influences minimally. In order to ensure the acceptance of the thermal environment of the specific passive occasions, such stiffened heavy wall design process should take into account the amount of overall thermal storage to determine the structural parameters of the wall. Besides, numerical simulation methods need to be used for the wall cool discharge simulation, through which we get its fitting time constant and check whether it meets the requirements of removal of indoor thermal disturbance in the whole control period.