ISBN 9783843941280

978-3-8439-4128-0, Reihe Energietechnik

Noah Klarmann
Modeling Turbulent Combustion and CO Emissions in Partially-Premixed Conditions Considering Flame Stretch and Heat Loss

154 Seiten, Dissertation Technische Universität München (2019), Softcover, A5

Zusammenfassung / Abstract

This study investigates combustion and CO emissions in cold conditions that occur in gas turbines operating at part load conditions. Moreover, the key research findings are used to develop a modeling strategy that is able to predict heat release and CO distributions. The models seek to support the development of new flexible designs and concepts for modern gas turbines that meet the requirements of the imminent new energy age. Combustion is described on the basis of flamelet generated manifolds. Important effects like flame stretch and heat loss are efficiently considered by a novel approach. Validation is performed by comparing the numerically predicted heat release with experimental OH*. Furthermore, a new CO methodology is proposed. CO is derived from flamelets within the turbulent flame brush. As the flamelet theory is not able to describe the burnout chemistry downstream of the turbulent flame brush, a model is introduced that predicts the transition from the theory of infinitely thin reaction zones to kinetically limited burnouts. Experiments have been conducted in which spatially resolved CO is obtained in order to validate the proposed methodology. Moreover, the validation in two different multi-burner cases is presented to demonstrate the model's capability of predicting CO in various fuel-staging scenarios. In addition, the CO modeling strategy is applied to a novel combustor concept to show basic mechanisms that are relevant in the context of this work.