Research on Analysis Method for Performance of Fuel Element Based on Thermal-Fluid-Solid Coupling

The existed fuel performance analysis tools are not applicable to the hollow prism fuel with special structure and operation conditions, so a new method is needed to assist the fuel design and evaluation. In this paper, a 3D fluid-thermal-solid coupling analysis method was established based on the COMSOL software by conjugate heat transfer technology and the equivalent material property models for particle reinforced composites, and had been verified with the General Electric data. Temperature and thermal stress of fuel elements in different sizes and axial power distributions were calculated with this method. The results show that maximum temperature exists at the side edge of prism, and maximum thermal stress exists at the thinnest inner wall. The thinner and longer fuel has the smaller maximum thermal stress and temperature. Flatting the axial power distribution in the entrance region can decrease the maximum thermal stress and temperature slightly. This analysis method can be used to optimize the design of the hollow prism fuel element.