Study on graphite particle motion and impact in the helium circulator of HTGR

Abstract The helium circulator is a key component in a high-temperature gas-cooled reactor. Here, the interactions between graphite dust and the circulator impellor are a matter requiring further investigations. In this paper, computational fluid dynamics is used to study the movement of particles in the vane channel, including the impact frequency, deposition fraction, and impact velocity of particles under the rated conditions. Then, based on the particle impact velocity, the finite element method is used to analyze the stress and strain during the impact of graphite particles on the FV520B vane wall. The results show that the deposition fraction for most of the graphite dust particle sizes is less than 1%. Large particles impact the wall with a higher velocity, which can reach 100 m/s. And the impact velocity in the vane is generally lower than that in the hub and shroud region. Finite element analysis results show that the maximum contact force increases, while the maximum stress decreases as particle diameter increases. Under the rated operating condition of the helium circulator, the wear of circulator wall due to the impact of graphite particles can be ignored.