Natural circulation flow and heat transfer studies in a supercritical pressure natural circulation loop

A closed Supercritical Pressure Natural Circulation Loop (SPNCL) has been set up to generate data on flow mid heat transfer behavior for supercritical fluids (i.e. water and carbon dioxide) under natural circulation conditions. Experiments were conducted in SPNCL with water as working fluid for different orientations of heater and cooler. The experimental steady state natural circulation mass flow rates have been compared with predictions of an in-house developed NOLSTA code. Besides, the steady state experimental heat transfer coefficients have been compared with predictions of various heat transfer correlations available in literature for supercritical fluids. The present paper describes the experimental results and comparisons in detail. (author)