大直径小环腔燃烧室点火性能实验研究

Experimental Investigation on Ignition Performance of Grand Scale Diameter-Small Annular Cavity Combustor

关键词:  燃烧室  贫油点火性能  插入深度  喷嘴间距比  油气比

Key words:  Combustor  Lean ignition performance  Insert distance  Ratio of nozzle spacing to cavity  Fuel-air-ratio

摘要:

为研究大直径小环腔燃烧室常温常压下的贫油点火性能，开展了燃烧室在不同进口马赫数（0.035~0.075），点火电嘴插入深度（-0.3~2.2mm），喷嘴间距比n=1.65和3.3下的点火实验研究，获得了进口马赫数、点火电嘴插入深度和喷嘴间距比等对贫油点火性能的影响规律。试验结果表明：在n=1.65时，随着进口马赫数的增大，燃烧室的贫油点火油气比快速下降，贫油点火边界拓宽，而点火电嘴的插入深度对燃烧室的贫油点火性能影响很小；在进口马赫数小于0.07时，n=3.3方案的贫油点火性能显著优于1.65方案；在相同进口马赫数下，着火时间及联焰时间随着油气比的增大而缩短；燃烧室的贫油点火边界受两个因数限制，燃油雾化颗粒度SMD不大于76μm和油气比不小于0.015。大直径小环腔燃烧室的喷嘴间距比设计能够远远突破常规燃烧室的设计值范围，达到3.3。

Abstract:

In order to study the lean ignition performance of the grand scale diameter-small annular cavity combustor， experimental investigations were conducted at ambient temperature and pressure. The ignition test of the combustor under different inlet Mach （0.035~0.075）， the insert distance of igniter （-0.3~2.2mm）， and the ratio of nozzle spacing to cavity n=1.65 or 3.3 were carried out， the effects of these parameters on the ignition performance were obtained. The experimental results indicate that， when n=1.65， with the increase of Mach，the fuel-air-ratio （FAR） of lean ignition decreased rapidly， the lean ignition boundary was broaden. The insert distance has little effect on the combustor ignition performance. When the Mach was less than 0.07， ignition performance of n=3.3 case was much better than that of n=1.65 case. Under the same inlet Mach， the formation time and propagation time of the flame decreased with the increase of FAR. The lean ignition boundary was limited by two factors， the SMD was not more than 76μm and the FAR was not less than 0.015. The n of the grand scale diameter-small annular cavity combustor could reach to 3.3， much higher than usual design.