小型部分预混燃烧器在PNG和LNG下的离焰和黄焰燃烧特性研究

Lifting and yellow tip characteristics of small-scale partially premixed combustor burning PNG and LNG

中文关键词: 小型部分预混燃烧器  燃烧器头部材质；管道天然气；液化天然气；离焰；黄焰；温度

英文关键词: small-scale partially premixed combustor  burner material  PNG  LNG  lifting  yellow tip  temperature

中文摘要:

      设计了一台功率为1.5 kW的小型部分预混燃烧器，其中燃烧器头部材质分别为铸铁和铜铝。通过改变燃气和空气预混比例，实验测试了不同PNG和LNG下燃烧器的离焰和黄焰特性，结合燃烧器头部温度变化规律，分析了在天然气置换后部分预混燃烧器的燃烧特性。实验发现：在发生黄焰时，铜铝材质拟合线性斜率分布在-6.2~-18.6，铸铁材质分布在-4.6~-9.0；在发生离焰时，铜铝材质拟合曲线曲率分布在1.3~2.7，铸铁材质分布在1.1~3.3,铜铝材质头部温度波动大，而铸铁材质保持相对平缓的温度变化趋势; 发生离焰时，在高火孔热强度下，LNG引射的空气量波动小，燃烧器头部温度基本不变, PNG引射的空气量下降，火焰根部温度出现上升; 黄焰发生时，LNG的引射空气量是PNG的1.2倍左右，引入过多的室内空气，导致燃烧器头部、火焰根部的温度降低。

英文摘要:

      A small-scale partially premixed combustor (SPPC) is designed with 1.5 kilowatt heat input rate. The burner header is designed by cast-iron and copper-aluminum, respectively. Through altering premixed ratio of gas and air, the lifting and yellow tip characteristics are experimental tested. Combined with burner head temperature influence, the combustion characteristics of SPPC are discussed when natural gas is substituted. It finds that in the occurrence of yellow flame, copper and aluminum material fitting linear slope distribution in -6.2~-18.6, cast iron material distribution in -4.6~-9.0; in the occurrence of lift flame, copper and aluminum material fitting curve distribution in 1.3 ~ 2.7, cast iron material distribution in 1.1 ~ 3.3; so the head temperature of copper and aluminum material is fluctuating a lot, but cast iron material is maintaining a relatively gentle temperature change trend. In the occurrence of lift flame, in the high port heat intensity, the injection volume of air is basically same during burning LNG, but drops during burning PNG which makes the temperature of flame root rise. When the yellow flame occurs, the amount of air during burning LNG is about 1.2 times more than the PNG situation. As more air injected into burner head, it is resulting in the flame root temperature decreases.