Experimental Study on the Combustion Performance of a Concentric-Staged Lean Direct Injection Combustor

Résumé fourni par la source

This study presents a comprehensive experimental investigation of a novel concentric-staged lean direct injection (LDI) combustor designed for civil aviation gas turbines. The combustor features a unique non-premixed combustion design, incorporating multiple coaxial airblast atomizers in the main stage and a pressure-swirl atomizer in the pilot stage. Through systematic testing, we analyzed the flow field of the concentric circular LDI combustor and evaluated key performance parameters, including ignition characteristics, lean blowout (LBO) limits, total pressure loss, combustion efficiency, pollutant emissions, wall temperature distribution, and combustion instability. Particle image velocimetry (PIV) revealed a stable central recirculation zone (CTRZ) within the concentric-staged LDI combustor that enhances flame stability. The minimum ignition fuel-air ratio (FAR) and LBO FAR are 0.0225 and 0.0066, respectively. The total pressure loss coefficient remained approximately 5% across all typical operating conditions. When operating with combined pilot and main stages, the combustion efficiency exceeds 99.9% across various FAR conditions, markedly higher than the 96.3 ~ 99.83% efficiency achieved with pilot-stage operation alone. During a landing and take-off (LTO) cycle, the combustor demonstrated exceptional emission reductions of 80.13% for NOX, 60% for CO, and 69% for UHC compared to CAEP/8 standards. Tangential effusion cooling (TEC) technology effectively maintained wall temperatures, with peak values below 900 K and maximum temperature differentials under 200 K relative to the combustor inlet temperature. Notably, pressure oscillation analysis confirmed combustion stability, with amplitudes remaining below 0.2 kPa under all operating conditions. These results validate the concentric-staged LDI design as a promising solution for high-efficiency, low-emission aviation gas turbine applications.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.