Flow and heat transfer characteristics of FLiNaK salt in an annular channel heater

Abstract

BackgroundThe simulation device is one-third scale of the 10 MW solid-fuel thorium molten-salt reactor (TMSR) and has the rated heat power of 370 kW. Nineteen annular channel heaters with wire coil were designed to heat the simulation device to the desired temperature.PurposeThis study aims to further investigate the effect of outer diameter of heating tube and annular width on the flow and heat transfer characteristics of FLiNaK salt in the annular channel heater.MethodsThe flow and heat transfer characteristics of annular channel heater with wire coil were simulated by using Fluent software. The effects of outer diameter of heating tube on the flow and temperature fields were investigated numerically, so did the effects of annular width on the flow and heat transfer characteristics. The overall performance of annular channel heater was evaluated by the principle of entropy production.ResultsThe simulation results show that the axial velocity, radial velocity and tangential velocity are generated and meanwhile counter-flow is formed on longitudinal section.ConclusionsThe outer diameter of heating tube has no effect on the flow and heat transfer characteristics. The larger the outer diameter of heating tube, the higher the energy efficiency. As the increase of the annular width, the pressure loss, the heat transfer coefficient decreases, and the energy efficiency gradually decreases.

Keywords

• wire coil
• annular channel heater
• flinak salt
• flow and heat transfer characteristics
• energy efficiency