Authors: G.J. Nel, O.C. Koekemoer, C.G. du Toit
Year: 2019
Industry: Nuclear & SMR
Keywords: Use FSE, Dynamic, HTR
ABSTRACT
The VHTR (Very High Temperature Reactor) Prismatic block reactor is one of the reactor designs considered in the range of 4th Generation Reactors which are under development today. The heat generated by the gas-cooled reactor can be used to produce electricity or as process heat to produce amongst others hydrogen. For the operation of the reactor under normal and upset conditions the conduction heat transfer through the prismatic block and the convection heat transfer to coolant is of critical importance. This paper discusses 3D and 1D computational fluid dynamic (CFD) models to simulate the heat transfer and fluid flow in a single-channel fuel module of a prismatic block. These models account for conduction heat transfer in the solids, convection heat transfer between the solids and fluid and fluid flow in the coolant channel in the single-channel fuel module. The current models represent one sixth of a single-channel fuel module. Detailed results are obtained for uniform and cosine power profiles by employing a 3D CFD code whilst representative results are obtained by a 1D system CFD code. The models are evaluated by comparing the temperature distribution results of the fuel compacts, coolant channel wall and the coolant, obtained by the different models with each other. The analyses of the study are performed employing the 3D CFD code STAR CCM+ and the 1D system CFD code Flownex. The 1D model requires much less computational resources than the detail 3D CFD and can form the basis of an integrated model for the entire core.