An improved correlation on the onset of heat transfer deterioration in supercritical water

On the basis of the supercritical water experimental data, the distribution of onset heat flux is analyzed for the heat transfer deterioration. This study evaluates the performance of empirical correlations for the prediction of heat flux, causing the onset of heat transfer deterioration in vertical tubes of supercritical water. In light of the calculation results, it is shown that the onset of heat transfer deterioration effect is better predicted using the Mokry, Li and Schatte criterion. On the basis of experimental data, a new correlation is developed for predicting the heat flux, which causes the onset of heat transfer deterioration in supercritical water. The new calculation model has considered the influence of mass flux, pipe diameter, pressure and inlet temperature. The newly developed correlation has an average relative error of 0.020837 and an average absolute deviation of 0.1627. The improved criterion is more conducive for the design of supercritical water reactors in the future.