文档介绍：燃气燃烧的低NOx排放实验研究与数值模拟
摘要
本文在天津市重点自然科学基金项目(高效低NOx排放燃气燃烧器的研究开发)的资助下,对燃气燃烧的低NOx排放完成了实验研究和数值模拟,为低NOx燃气燃烧器的开发提供指导。
首先建立了完善灵活的低NOx燃烧实验系统,在实验系统上完成了燃烧温度、过量空气系数、预先加入一定量的水蒸汽、空气预热温度、对燃气预先进行微波处理、烟气再循环燃烧以及燃烧方式(扩散式与预混式)对NOx生成的影响分析;采用PHOENICS 。
本文通过实验得出了燃烧室出口NOx的浓度随燃烧室出口温度的增加而增加。,NOx的生成量急剧增大。对目前普遍认为的分级燃烧和浓淡燃烧可以降低NOx排放的提法给予补充,即对一次过量空气系数有一个最小值限定,不是小于l的任何值都可以,低于最小限定值将是不利的,而且一次过量空气系数有一个最佳值。最小值和最佳值要依据燃料而定。首次发现在燃气燃烧以前预加入少量水蒸汽能降低70%以上的NOx排放,同时也大大降低cO和CH的排放。得出燃烧室出口NOx的浓度随预热空气温度的增加而增加。发现经过微波处理后的燃烧能得到较可观NOx浓度的降低。利用特殊设计的烟气再循环式燃气燃烧器做实验,发现得到较低的NOx排放。利用PHOENICS 。
关键词:燃气,低NOx,实验研究,数值模拟
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EXPERIMENTAL INVESTIGATION AND NUMERICAL
SIMULATION OF LOW NOx EMISSION IN BUTION
ABSTRACT
Supported by the Important Natural Science Foundation of Tianjin(Research and Development of Low NOx Emission of Gas Burners with High Efficiency),experimental investigation and numerical simulation of low NOx emission in bustion are plished in this paper,which provides guidance for the development of low NOx emission ofgas burners.
In this paper a perfect and flexible experimental system of low bustion is
established influences of the tempemture bustion,the air excess coefficient(中),a certain amount of vapor added in advance,the temperature of preheated air,adding microwave into gas bustion,gas bustion and the mode
bustion(diffused and premixed)on NOx emission are analyzed ofLiquid Petroleum Gas iS simulated with PHOENICS .
The NOx concentration increases with the temperature of Outlet of bustion is firstly found that the NOx concentration increases rapidly when巾is less than the bustion and the rich-bustion that are well considered currently as low does not mean that bustion must be
the low bustion when巾< iS a limited least value of air excess
iS not the lOW bustion when巾iS less than the limited least