Experimental Study on the Thermal Hydraulic Characteristics of Liquid Sodium Flowing in an Annulus

Thermal hydraulic characteristics of liquid sodium flowing in an annulus are experimentally studied. The annulus is 1100 mm in length, 6 mm as inside diameter and 10 mm as outside diameter. The heat flux in the experiment is from 50 to 210 kW/m², with Re number from 0 to 18000 and average fluid temperature from 200 °C to 500 °C. Experimental data show that the flow regime of liquid sodium flowing in the annulus can be divided into three regions including laminar flow (Re<2000), transition flow (2000<Re<4000) and turbulent flow (Re>4000). The effects of heat flux, Re number and average fluid temperature of the test section on the heat transfer coefficient are investigated separately. For different regions, correlations for the friction coefficient and for the Nu number are obtained from the experimental data.