Reducing Dissolved Oxygen Under Conditions of High Air Ingress

Recent considerations of steam and air mixture dynamics in operating condensers has led to a more thorough understanding of how condenser performance is affected by air in-leakage. Results of this model-based theoretical description, which are in agreement with measurement data from operating condensers, are reviewed and used to propose beneficial design features for new and re-tubed condenser assemblies. It is anticipated from this work, that condensers can be designed which significantly reduce the amount of dissolved oxygen in condensate from locations of free air ingress above the hotwell level. This reduction also applies to other undesirable noncondensables that enter condensate driven by the same mechanism contributing to dissolved oxygen. When air in-leakage becomes sufficiently high, it contributes to excess back pressure on the turbine. In this region of high air in-leakage, the amount of dissolved oxygen can become very high. The design therefore, minimizes or eliminates the corrosive effects of air inleakage, both high and low, which is particularly important during periods of high demand when load must be maintained.