应用计算流体力学研究低热值火炬燃烧过程

Study on the Combustion of Low Calorific Value Gas Flare Using CFD Technology

为获得低热值火炬安全设计及运行中所需基础数据,采用计算流体动力学的方法建立了低热值火炬燃烧模型,对典型的低热值火炬燃烧过程进行了模拟研究,得到了低热值火炬气燃烧产物分布、温度场等基础数据。结果表明,低热值气体在燃烧过程中会产生NOx,其中主要为NO;NO主要是由N2在高温下氧化而生成的,即热力型NOx,低热值火炬燃烧器设计时,应注意采取措施降低热力型NOx的产生。低热值气体燃烧时的CE和DRE均小于98%,因此低热值火炬设计和运行时,应考虑燃烧效率的问题,通过掺烧或伴烧的方法提高其燃烧效率。

In order to obtain the key parameters for the safety design and operation of low calorific value gas flare the combustion model of low calorific value gas flare was built. The typical combustion of low calorific value gas flare was simulated,and the temperature field,concentration field of combustion products and combustion efficiency were obtained. The result showed that NOx was produced in the combustion of low calorific value gas flare,and NO is the primary ingredient of NOx. The NO was produced by N2 oxidation at high temperature,which was thermal NOx.So measures should be taken in the design and operation of low calorific value gas flare to control the generation of thermal NOx. The CE and DRE were both lower than 98%,so the combustion efficiency should be considered in the design and operation of low calorific value gas flare. And the combustion efficiency could be improved by blended combustion or co-combustion.