Improvement of Feed-Water Heater and Three-Dimensional Two-Phase Flow Analysis. Numerical Simulation of Gas-Liquid Two-Phase Flow Behavior with Condensation Heat Transfer

In order to evaluate the heat transfer performance in a feed water heater, a three-dimensional analysis for the heater of a power plant was conducted with a computational code for two-phase flow using a two-fluid model. In a conventional feed-water heater which was divided into six sections in the axial direction. the steam flowed mainly into both end sections. Therefore the overall heat-transfer coefficient was large there. Based on the calculated results, an improved feed-water heater was proposed in which the support plate had a hole leading the steam into the neighboring sections. In the improved feed-water heater, the steam flowed from the steam inlet section to the neighboring sections through the hole in the support plate, and the steam velocity was generally larger than that in the former heater. Therefore the overall heat-transfer coefficient was also larger.