Experimental and CFD Study on Natural Circulation Phenomenon in Lead Bismuth Eutectic Loop

Abstract

A test loop, HANS (Heavy metal Alloy Natural circulation Study loop) is installed in BARC (Bhabha Atomic Research Centre) for thermal hydraulic, instrumentation development and material compatibility related studies in Lead Bismuth Eutectic (LBE) coolant. Steady state natural circulation characteristics in the LBE loop were investigated at different power levels. Significant natural convection flow was observed in the experiments. It was found that the natural circulation was easily established and stabilized. It took only a few minutes to have a stable natural circulation at a constant power level. The natural circulation flow rate depends on the loop resistance and the temperature difference between the hot leg and the cold leg, as determined by the power level and the heat sink capacity. The heater power is varied from 1200W to 2700W and the temperature difference found across the heater is 80°C to 165oC. The natural circulation in the loop is simulated in a CFD code PHOENICS. The predictions of PHOENICS code are found to be in good agreement with the experimental data.