Experimental and theoretical studies on the natural circulation behavior of molten salt loop

Highlights: • A Molten Salt Natural Circulation Loop (MSNCL) has been setup. • Various steady state and transient experiments have been carried out in the loop. • Natural circulation steady state correlation is compared with the experimental data. • In-house developed code, LeBENC, has been validated with the steady state and transient experimental data. - Abstract: Molten salts are increasingly getting attention as a coolant and storage medium in solar thermal power plants and as a liquid fuel, blanket and coolant in High Temperature Reactors (HTR). A Molten Salt Natural Circulation Loop (MSNCL) has been setup for thermal hydraulics, instrument development and material related studies relevant to HTR and solar power plants. The loop mainly consists of heated section, air heat exchanger, valves, various tanks and argon gas control system. All the components and piping of the loop are made of Inconel 625. Steady state natural circulation experiments at different power level have been performed in the loop. Transient studies for startup of natural circulation, loss of heat sink, heater trip and step change in heater power have also been carried out. A one dimensional code LeBENC, developed in-house to simulate the natural circulation characteristics in closed loops, has been validated with the experimental data obtained from MSNCL. This paper deals with the description of the loop and experimental studies carried out in the loop. Detailed validation of the LeBENC code with the experimental data has also been discussed in the paper.