Sensitivity analysis of internal flow distribution in the Tsinghua high flux reactor

Abstract

This paper presents a simple approach for rapidly analyzing the flow distribution characteristics and sensitivity within the THFR (Tsinghua High Flux Reactor). Given the high flow rates and large mixing space provided by the upper and lower chambers in the high flux reactor, the flow network theory aligns well with these assumptions, resulting in good agreement between the theoretical calculations and CFD simulations. Based on the flow network theory, the sensitivity analysis of the internal structural flow areas within the reactor indicates that changes in the flow channel area typically dominate the impact; variations in the flow area of the larger control drums and external irradiation boxes have a more significant overall effect. In subsequent design iterations, adjusting the flow resistance distribution ratio among the branches can mitigate the impact of potential dimensional changes on the overall flow distribution. Meanwhile, variations in channel dimensions significantly alter the pressure drop, imposing higher demands on the pumps.