Session: Student Poster Competition

Submission Number: 187007

A Model-Derived Control Strategy for Hydrogen Co-Firing Gas Turbines Under Transient Co-Firing Ratio Variations 

As the transition toward carbon neutrality accelerates, hydrogen co‑firing is considered a key pathway for decarbonizing large‑scale gas turbine systems. Many research and industrial programs are now focusing on converting conventional natural-gas-fired gas turbines into hydrogen co-firing systems. However, the distinct thermophysical properties of hydrogen compared to methane significantly influence the flow‑control characteristics within the fuel supply system. These differences make it difficult for conventional proportional‑integral (PI) controllers—originally designed for methane operation—to respond effectively to rapid variations in hydrogen concentration, thereby affecting the overall performance of the gas turbine and operational stability.

In this study, an integrated dynamic model that couples the gas turbine and fuel supply system was developed using Flownex SE for system‑level configuration to investigate the control characteristics under hydrogen co‑firing conditions. Using this configuration, the transient response of power output and temperature was analyzed under various hydrogen co-firing scenarios. The results indicate that increasing the rate of change of the co-firing ratio amplifies response delay and tracking error, revealing fundamental limitations of conventional PI-based control when fuel composition acts as a strong external disturbance.

To mitigate these effects, a model-derived control strategy was proposed in which the required operating state of the fuel supply system is predicted based on the target co-firing level and operating condition. From this model, a valve opening schedule was derived and applied during rapid co-firing transients, such as hydrogen supply trips. When the proposed schedule-based control was implemented, valve actuation and fuel composition regulation were performed more consistently, leading to a significant reduction in power and temperature deviations compared to the conventional PI control scheme.

This study extends beyond conventional performance evaluation to highlight the critical role of control stability in hydrogen co‑firing gas turbines. The findings emphasize the necessity of developing model‑based control strategies capable of maintaining reliable operation under varying hydrogen blending conditions.

Presenting Author: Jin Seo Kim Inha University

Presenting Author Biography: Jinseo Kim is a Ph.D. candidate in Mechanical Engineering at Inha University, Republic of Korea.
His research focuses on hydrogen co-firing gas turbines, performance modeling, and control strategies for zero-carbon energy systems.

Authors:

Jin Seo Kim Inha University
Yong Hyeon Kwon Inha University
Tong Seop Kim Inha University