Performance Increase of Steam Turbine Condensers by CFD Analysis

Abstract

An effective measure to increase the performance of turbine power plants is to minimize flow losses in the condenser resulting in a smaller terminal temperature difference (TTD) — the more the TTD of the condenser can be reduced in an optimization process of a given power plant configuration, the more the exhaust pressure will decrease. With an optimized condenser tube bundle design the TTD can be improved. This study presents the modification of a commercial CFD code to simulate the three-dimensional flow field around and within tube bundles. Additionally the temperature distribution of the cooling water is part of the numerical solution without modeling each individual condenser tube. To show the accuracy of the CFD code the flow in a large scale power plant condenser is simulated and compared to measurements of local heat transfer coefficients in the bundles. The comparison shows that the presented CFD tool is valid to predict the performance of such condensers. Based on the results of the study, areas with low cooling performance are identified and suggestions are made for the increase of the overall condenser efficiency.