Flow and heat transfer of supercritical water in the vertical helically-coiled tube under half-side heating condition

Abstract

Flow and heat transfer of supercritical water in the vertical helically-coiled tube were investigated numerically using RNG k-ε model. The inner side of the coil was heated by constant heat flux and the outer side was adiabatic. Heat transfer performance under half-side heating is obtained and compared with that under uniform heating at the same heat transfer rate. Effect of specific heat, secondary flow velocity and buoyancy are discussed. The decrease of specific heat in the near-wall region, and the attenuated turbulence caused by the strong buoyancy force lead to a decrease in heat transfer for half-side heating. The deviations of heat transfer correlations on predicting half-side heating condition are evaluated, and a new heat transfer correlation for supercritical water in the vertical helically-coiled tube under inner half-side heating is proposed. The investigation into different statistical parameters shows that it is superior to the existing correlations.