Critical heat flux for subcooled flow in an annulus with bilateral heating

The critical heat flu was measured at the outer surface of an annulus with D-1=28mm, D-0=35.7mm, covering the range of pressure of 3.14-3.95bar, water velocity of 2.55-8.12 m/s, exit subcooling of 49.1-76.6K, q(cr)=5.91-12.02x10(6)w/m(2) and the ratio of heat fluxes of q(1)/q(2)=0-0.94. The data showed an increase of the CHF with increasing the heat flux on the inner surface. The results were analysed with a model based on the energy equation in the liquid core. Incorporating a modified subcooling an empirical correlation was proposed for both single surface heating and bilateral heating.