A Micro Gas Turbine Fuelled by Methane-Hydrogen Blends

Abstract

The combustion efficiency and the gaseous emission of a 100 kWe MGT, designed for working with natural gas but fuelled with blends containing up to 10% of hydrogen is investigated. A critical comparison between experimental data and results of the CFD analysis of the combustor is discussed. The k-epsilon RANS turbulence model and the Finite Rate – Eddy Dissipation combustion model were used in the numerical computations. The chemical kinetic mechanisms embedded were the 2-step Westbrook and Dryer for methane oxidation, 1-step Westbrook and Dryer for hydrogen oxidation and the Zeldovich mechanism for NO formation. The experimental data and numerical computations are in agreement within the experimental accuracy for NO emissions. Regarding CO, there is a significant deviation between experimental and computational data due to the scarce predictive capability of the simple two steps kinetic mechanism was adopted. From a practical point of view, the possibility of using fuels with a similar Wobbe index was confirmed. In particular the addiction of 10 % of hydrogen to pure methane doesn’t affect the behavior of the micro gas turbine either in terms of NO or CO emissions.

Challenges and Solutions for Utilization of Bioliquids in Microturbines

“…Several studies were performed also purely on virtual level what was in some cases a prerequisite for performed experimental work. Thus 0-D and CFD analyses of combustion chambers were performed in several studies either with the aim to analyze the atomization, mixing and combustion process [47], [48], [49], [50], [51], [52], [53], however most of the research was oriented towards gaseous biofuels which are out of the scope of this paper.…”

Transient Analysis of a Micro Gas Turbine With Fuel Composition Change

“…The analysis showed that it is possible to operate with 10% of H2 in volume even at part load, while higher amounts can lead to flashback issues. The safe operation at 10% of H2 in volume was also demonstrated experimentally by Reale et al [12]. The use of hydrogen for higher concentrations presents several challenges due to the different combustion characteristics compared to conventional fossil fuels, such as higher low heating value (LHV), higher reactivity, flame speed and burning velocity.…”

Numerical Modeling of Energy Systems Based on Micro Gas Turbine: A Review

“…Results showed that the typical fuel addition of lean premixed combustors, from both main and pilot lines, presents the risk of flashback phenomena for hydrogen concentration higher than 10%, while the pseudo-RQL combustor can operate also with 20% hydrogen blends. Reale et al [101] compared experimental data and results of CFD simulations of a Turbec T100 MGT fueled by three different hydrogen/methane blends (H 2 up to 10% in volume). The authors highlighted, as regard carbon monoxide, the significant deviation due to the limited prediction capability of the adopted simple two-step kinetic mechanism.…”