Experimental research on convective heat transfer characteristics of molten salt in a pebble bed channel with internal heat source

•Convective heat transfer experiment of molten salt in a pebble bed channel was conducted in SINAP, with the pebble diameter of 60 mm.•Induction heating method was used to realize internal heat source in the pebbles, simulating fission heat in the fuel pebbles of TMSR.•A new convective heat transfer correlation for molten salt was obtained, which is applicable within the Prandtl number range of 11.3–14.5 and Reynolds number range of 2800–6600. Convective heat transfer between the molten salt coolant and the fuel pebbles in the reactor core is one of the key thermal hydraulic phenomena for Thorium Molten Salt Reactors. In this study, a pebble bed experiment facility using induction heating to provide internal heat source is designed. The heat transfer characteristics of molten salt in the pebble bed channels are studied on the Heat Transfer Salt (HTS) loop. The effects of inlet temperature, molten salt flow rate and induction heating power are investigated on convective heat transfer characteristics. A new correlation is proposed for predicting the convective heat transfer coefficients of molten salt with Prandtl number at 11.27–14.51 and Reynolds number at 2800–6600. The results will provide an important reference for the core design of thorium based molten salt reactor.