ARHP - プラズマ制御を用いた水素の先進再熱燃焼

Unofficial AI-generated summary based on the public title and abstract. Not an official translation.

🔬研究者:水素逐次燃焼における燃焼形態遷移と熱音響不安定性の連成、およびプラズマによる能動制御の実験的基礎を提供する。

🏢実務担当者:水素発電設備の燃焼振動対策・低NOx運転設計において、省エネルギーなプラズマ制御の実現可能性を示す。

🏛政策担当者:水素発電の実装可能性と技術課題を踏まえ、水素供給・発電導入支援策の設計に資する。

The decarbonization of the power sector requires reliable, flexible power generation technologies capable of operating with carbon-free fuels. Hydrogen is a particularly promising carbon-free and renewable fuel for this purpose, enabling seasonal storage of surplus renewable electricity and its reconversion to power on demand via gas turbines. However, burning pure hydrogen in gas turbines introduces significant engineering challenges, including elevated NO𝑥 emissions, high reactivity and diffusivity, and subsequent thermoacoustic instabilities. The CPSC architecture is well suited to address these challenges. It burns two lean flames one after the other in the same combustor: the first is stabilized by the flow, while the second auto-ignites due to the high gas temperatures provided by the first flame. Air added between the two stages keeps flame temperatures and emissions low. This two-stage design enables ultra-low-NO𝑥 pure hydrogen operation across a wide load range. Nevertheless, thermoacoustic instabilities can arise and must be mitigated to prevent hardware damage and maintain operational flexibility. The ARHP project investigated two interconnected aspects of hydrogen sequential combustion at elevated pressure: the characterization of combustion regimes and their coupling with thermoacoustic stability, and the development of a plasma-based active control strategy. Experiments were conducted in a laboratory-scale CPSC operated with pure hydrogen in both stages, at pressures of 1, 2, 3, and 4 bar. Three distinct combustion regimes were identified at atmospheric pressure: a propagating regime, a periodic autoignition regime, and a steady autoignition regime. At elevated pressure, the periodic regime disappears and the transition between propagating and autoignition becomes abrupt, a behavior explained by zero-dimensional kinetic simulations showing a strong sensitivity of the hydrogen autoignition delay to inter-stage temperature above approximately 2 bar. pac was investigated using nrpd applied upstream of the second-stage combustion chamber. The original conical electrode geometry, previously used for methane–hydrogen blends, caused irreversible flame anchoring in pure hydrogen at elevated pressure, motivating the design of new cusp-shaped electrodes with a 15 mm inter-electrode gap. With this configuration, on-demand thermoacoustic stabilization was demonstrated at 2, 3, and 4 bar. Stabilization was achieved through a plasma-induced shift of the flame anchoring position from the combustion chamber into the SB, suppressing the thermoacoustic limit cycle at 334 Hz. The two main discharge parameters, applied voltage (20–30 kV) and PRF (0.2–50 kHz), were varied systematically at each pressure. Applied voltage was identified as the dominant control parameter, while PRF played a secondary role, allowing plasma to be applied at reduced frequency, limiting energy consumption and minimizing electrode wear. Satisfactory stabilization was achieved with a plasma-deposited power as low as 0.01% of the total combustor thermal power, confirming the energy efficiency of the approach. These results establish an experimental and physical foundation for plasma-assisted control of hydrogen sequential combustion. Future work will focus on extending the demonstrated approach to higher pressures closer to gas turbine operating conditions, optimizing electrode geometry for long-term durability, and validating closed-loop plasma control under variable-load operation.

• Zenodo https://zenodo.org/records/23469111first seen 2026-10-20 04:11:28 · last seen 2026-10-22 04:12:57