Impact of pilot flame and hydrogen enrichment on turbulent methane/ hydrogen/air swirling premixed flames in a model gas turbine combustor

被引：5

作者：

Pignatelli, F. ^{[1
]}

Sanned, D. ^{[2
]}

Derafshzan, S. ^{[2
]}

Szasz, R. Z. ^{[1
]}

Bai, X. S. ^{[1
]}

Richter, M. ^{[2
]}

Ehn, A. ^{[2
]}

Lorstad, D. ^{[3
]}

Petersson, P. ^{[4
]}

Subash, A. A. ^{[2
]}

机构：

[1] Lund Univ, Dept Energy Sci, Div Fluid Mech, S-22100 Lund, Sweden

[2] Lund Univ, Dept Phys, Div Combust Phys, S-22100 Lund, Sweden

[3] Siemens Energy AB, Finspang, Sweden

[4] Dantec Dynam A S, Skovlund, Denmark

来源：

EXPERIMENTAL THERMAL AND FLUID SCIENCE | 2024年 / 152卷

基金：

瑞典研究理事会;

关键词：

Swirl-stabilized flames; Pilot flame; IRZ; PIV; OH-PLIF; Flame dynamics; Hydrogen; FRONT STRUCTURE; BLUFF-BODY; BURNING VELOCITY; HIGH-PRESSURE; NATURAL-GAS; OH; FUEL; PLIF; PERFORMANCE; STABILITY;

D O I：

10.1016/j.expthermflusci.2023.111124

中图分类号：

O414.1 [热力学];

学科分类号：

摘要：

This work investigates the impact of pilot flame and fuel composition on the structures and stabilization of swirling turbulent premixed methane/hydrogen/air flames in a lab-scale gas turbine model combustor. Simultaneous measurements of the velocity field and OH radicals distribution in the combustor were conducted using particle imaging velocimetry (PIV) and planar laser-induced fluorescence (PLIF) methods, respectively. Flames under stable and close to lean blow-off (LBO) conditions were studied for two fuel mixtures, with a hydrogen mole ratio of 0 and 50 % in the hydrogen/methane mixture, respectively. The studied flames were at a constant Reynolds number of 20,000 with different equivalence ratios. Two pilot-to-global fuel ratios were investigated (2 % and 6 %) while keeping the pilot-to-global air ratio constant at 2 %. Data for non-piloted flames were also acquired for comparison. The pilot flames were shown to extend the operability range. The LBO equivalence ratio of the main flame decreased with increasing fuel mass flow rate in the pilot flames due to the increased amount of hot gases with high concentrations of OH radicals in the outer recirculation zone (ORZ), which significantly enhanced the stabilization of the main flame. The stable flame reaction zone was in the high-speed shear layer between the ORZ and the inner recirculation zone (IRZ). When approaching LBO, the reaction zone was pushed downstream to the IRZ and subsequently decreased the size of IRZ, indicating a strong flow/flame interaction. Hydrogen enrichment was shown to reduce the LBO equivalence ratio. When close to LBO, the OH radicals in the hydrogen-enriched flames were observed in isolated pockets due to differential diffusion, which enhanced resilience to LBO. The flame front curvature, mean progress variable, and flame surface density were calculated from the acquired OH-PLIF data to quantify the impact of fuel composition and pilot flames on the flame structures.

引用

页数：14