Session: 03-02 Advanced Modeling and Retrofit Techniques for Hydrogen and Mixed-Fuel Combustion Systems

Paper Number: 153827

Retrofit of a 100 kW Micro Gas Turbine for the Use of Hydrogen and Mixtures of Hydrogen and Natural Gas 

It is anticipated that gas turbines will continue to play a significant role in the future energy system, particularly in the context of grid stabilization, imposed by the intermittent and variable energy output of renewable sources. It will be essential for future gas turbines to be capable of running on hydrogen, preferably green hydrogen. At present, the capacity to produce sufficient quantities of green hydrogen to meet the demands of all sectors is inadequate. Accordingly, a transitional period will ensue during which admixtures of hydrogen to natural gas up to pure hydrogen will be employed in conjunction with natural gas. This necessitates the implementation of highly fuel-flexible systems. Furthermore, the financial outlay associated with the acquisition and construction of new power plants is considerable. One potential solution is the retrofit of existing gas turbine-based power plants for the utilization of hydrogen and mixtures of hydrogen and natural gas.

A collaborative project was undertaken by the DLR Institute of Combustion Technology and the Power Service Consulting GmbH (PSC) examining the retrofit potential of existing gas turbine power plants with a capacity of up to 100 MW_el. In order to demonstrate the feasibility, the commercially available micro gas turbine (MGT) AE-T100, manufactured by Ansaldo Green Tech, with an electric power output of 100 kW was selected for analysis. It is combining relatively compact dimensions with the potential for scaling up the results to larger gas turbine systems. The demonstration plant was equipped with a fuel mixing device that allows the user to specify the desired fuel composition, ranging from pure hydrogen to mixtures of hydrogen and natural gas, and finally to pure natural gas. The fuel system of the MGT was modified to accommodate hydrogen, and the safety system was updated. The combustion chamber is the core component that requires adaptation for hydrogen use. Consequently, a new combustor was developed using CFD methods and tested under atmospheric conditions. Based on these findings, two prototypes were derived for the testing in the actual MGT system.

This study presents a detailed account of the retrofitting process for the micro gas turbine AE-T100. The modifications to the MGT are explained. To upgrade the safety system, flow simulations were performed to determine the optimal location for supplementary sensors. An additional instrumentation package was installed in the MGT, comprising thermocouples and pressure transducers. The internal measurement data was recorded and the emissions were quantified using a Horiba gas analyzer system for CO, CO₂, NO_x and O₂. A measurement campaign was conducted to investigate the two prototypes, with an analysis of the operation with pure hydrogen in transient as well as in steady state conditions. Additionally, the admixture of natural gas was investigated with a focus on emissions and the stability of the combustion process.

Presenting Author: Martina Hohloch German Aerospace Center (DLR)

Presenting Author Biography: Dr., Hohloch, Martina, research engineer in department of micro gas turbines, is graduated in process engineering, holds a PHD and has been working at DLR for 18 years.

Authors:

Martina Hohloch German Aerospace Center (DLR)
Timo Lingstädt German Aerospace Center (DLR)
Peter Kutne German Aerospace Center (DLR)
Markus Wächter Power Service Consulting GmbH (PSC)
Philipp Körner Power Service Consulting GmbH (PSC)
Tze-Yeung Cheung Power Service Consulting GmbH (PSC)