摘要
针对某型航空发动机燃烧室,探究将其改造为天然气湿燃烧低污染燃烧室的可行性。采用计算流体力学方法,研究了压力(1~2.33 MPa)、空气预热温度(510~790 K)及加湿比例(0~2.0)对温度分布、污染物排放的影响。通过Chemkin软件进行参数化计算,对全局当量比进行补偿,以确保燃烧室出口温度均达到设计值。计算结果表明:高压工况下,火焰向燃烧室出口方向延伸,导致出口径向温度分布恶化,其中,压力2.33 MPa时NO_(x)排放量是常压下的10倍;较高的空气预热温度将导致NO_(x)排放量增加,但同时可能有利于消除局部高温区;NO_(x)排放量随加湿比例的提高单调下降,但CO质量浓度表现出先降后增的趋势;无当量比补偿时NO_(x)质量浓度偏差最高达到90.7%;综合考虑NO_(x)和CO的排放特性,改造后燃烧室最佳燃料加湿比为1.5。
The feasibility for a certain aero-engine combustor to be remodeled into a natural gas combustor is explored.The effects of pressure, air preheating temperature and humidification ratio on temperature field and pollutants emission were studied by means of computational fluid dynamics.Working conditions are pressure 1~2.33 MPa, temperature 510~790 K and humidification ratio 0~2.0,respectively.Compensation for total equivalence ratio against outlet temperature deviation, which is caused by changing working conditions, is considered.This ensures desired outlet temperature.The results show that under high pressure condition, the flame extends towards the combustion chamber exit, resulting in worse radial temperature distribution at the exit, and NO_(x) emission at 2.33 MPa is 10 times as much as that at atmosphere condition.The increase of air preheating temperature will lead to the increase of NO_(x) emission, but the elimination of local high temperature zone is observed.Fuel humidification always has a beneficial effect in emissions reduction, while the mass concentration of CO emission decreases first and then increases with the increase of humidification ratio.The NO_(x) emission deviation reaches 90.7% without equivalence ratio compensation.Considering the emission characteristics of NO_(x) and CO,the optimum humidification ratio of the modified combustor is 1.5 in this case.
作者
李威
张哲巅
LI Wei;ZHANG Zhe-dian(University of Chinese Academy of Sciences,Beijing,China,Post Code:100049;Key Laboratory of Advanced Energy and Power,Chinese Academy of Sciences(Institute of Engineering Thermophysics),Beijing,China,Post Code:100190)
出处
《热能动力工程》
CAS
CSCD
北大核心
2021年第5期126-133,共8页
Journal of Engineering for Thermal Energy and Power
基金
国家科技重大专项(2017-I-0009-0010)。
关键词
燃烧室
当量比补偿
压力
空气预热温度
加湿比例
污染物排放
combustor
equivalence ratio compensation
pressure
air preheating temperature
humidification ratio
pollutant emissions
