Session: Student Poster Competition

Submission Number: 187181

Study of Exhaust Gas Recirculation and Humidification Mitigating Effects on Adverse Effects of Hydrogen Combustion in a Micro Gas Turbine 

Shifting to carbon-free fuels such as hydrogen within existing infrastructure presents several challenges including higher flame temperature and increased NO_x emissions. To mitigate these effects without combustor redesign, exhaust gas recirculation (EGR) and humidification represent viable strategies for gas turbines and micro gas turbines.

 For this purpose, experimental tests conducted on a 3 kW_e micro gas turbine operating with hydrogen enriched methane fuels containing up to 50% vol. hydrogen under several EGR ratios. To develop a computationally inexpensive model of the micro gas turbine combustor, a chemical reactor network (CRN) was developed using both experimental measurements and computational fluid dynamics (CFD) data. The CRN model was validated against measured combustion emissions as well as key CFD extracted parameters such as TIT and heat release rate (HRR). Developed CRN was subsequently used to analyze the tested operating conditions and extrapolated to higher hydrogen contents to assess the feasibility of approaching 100% hydrogen operation with EGR and humidification enabled. This investigation included laminar flame speed evaluation, kinetic pathway analysis, and HRR distribution. 

The results indicate acceptable agreement between the CRN predictions and both experimental and CFD simulations, capturing the main combustion zones in the combustor and predicting emissions within an acceptable margin of error. Application of the CRN to fuel blends exceeding 50% hydrogen indicates that safe operation requires either moderate EGR dilution or humidification. Moreover, the model enables the use of detailed kinetic mechanisms, providing improved emission predictions and deeper insight into NO_x and CO formation hotspots within the combustor.

Presenting Author: Farshid Yousefzad Farrokhi UMONS-ULB

Presenting Author Biography: PhD student in energy and mechanical engineering working on micro gas turbines combustion, EGR, humidification, and cycle efficiency.

Authors:

Farshid Yousefzad Farrokhi UMONS-ULB
Alessandro Piscopo UMONS-ULB
Alessandro Parente ULB
Ward De Paepe UMONS