Hydrogen Co-Firing Characteristics in a Single Swirl Burner: A Numerical Analysis

Abstract

Hydrogen is gaining traction as an energy carrier in the decarbonisation and net-zero-emissions agenda. Because hydrogen is a clean energy carrier, increasing the percentage of hydrogen in natural gas mixtures aids in the decarbonisation initiatives. Hence, the flame characteristics of the natural gas mixtures, together with hydrogen are explored in the current study through a numerical assessment of a single swirl burner (swirl number, SN 0.78) since the said burner is widely used in gas turbine (GT) combustors. The baseline CFD and experimental cases referred to natural gas compositions primarily composed of methane (CH4). The results reveal that the CFD model can effectively represent the swirling component of the flame as seen in the experiment. A 5% hydrogen addition had virtually no effect on the swirling flame structure, as shown by qualitative evaluation of hydroxyl (OH) behaviour and flame temperature in comparison to the baseline methane flame. Despite this, the addition of hydrogen has increased the OH radical pool during combustion, causing a small change in flame temperature. Overall, the novelty of the current research is the opportunity to fire 5% hydrogen in a CH4-dominated GT combustor without any major retrofitting operations, as the study discovered that 5% hydrogen in a pure CH4 stream has a minor affect. However, more research is needed to properly capture the flame structure and strain for assessing transient-related phenomena like flashback and blow off by increasing the hydrogen proportion and using a higher accuracy turbulence model.