Magnetic Bearing System Design for Canned Molten Salt Pump Application

Abstract

The increasing demand for more efficient, clean and power dense energy has led to the interest in developing the next generation of molten salt reactor (MSR) to harness nuclear energy. In order to develop the next generation of MSR, an efficient, reliable and leak-free pump able to operate at high temperatures and in an extreme environment is needed. By using magnetic bearings to externally support the canned-pump, a low friction, virtually infinite life and high temperature capable pump can be developed. The designed magnetic bearing system is responsible for suspending the rotating shaft to speeds up to 3600 rpm at a temperature of 550°C both in the radial and axial direction. The key challenges for the design involve having a large magnetic gap, managing thermal stresses, maintaining desired clearances and preventing corrosion in the molten salt environment.

The thesis utilized a 3D magnetostatic finite element analysis (FEA) solver to predict the bearing’s force capability. Additionally, static structural FEA was conducted to prevent thermal stresses from developing. The various FEA studies were verified using simple representative models. Through critical design review (CDR), the design’s maturity was demonstrated to proceed with fabrication.