Numerical investigation on the thermal-hydraulic performance of separated structure steam generator with different tube arrangements

Abstract

The horizontal steam generator is generally used in nuclear power plant and industry to produce steam. To increase the heat load and reduce the size, a steam drum can be added above the shell. However, it makes the overall flow of water cycle complicated. In this article, the two-phase boiling flow and heat transfer inside tube bundle under the separated structure has been investigated numerically based on the previous experiment. The Drift-Flux model was utilized to solve the equations of heat and mass transfer in the mixture flow. The local pressure drop, void fraction and heat transfer characteristics have been presented and discussed for different arrangements in detail. The analysis results showed that the overall boiling HTC of the tube arrangements of 30°and 60° appear better for this steam generator under the same condition. The boiling heat transfer in both bottom and upper tube bundle was mainly controlled by the nucleate boiling mechanism. However, both heat flux and vapor void fraction were found to affect the heat transfer performance. Beyond this analysis, a new type of heat transfer correlation has been proposed herein to evaluate the local HTC with a good accuracy. These correlations allow better predictions of the boiling heat transfer inside the SS-SG, which provide designers with better reference and guidance.