钝体稳定煤粉火焰的一维数学模型研究

本文在大量实验研究的基础上提出了钝体稳定煤粉火焰的一维数学模型.数值计算表明,由该模型计算出的温度分布与相应实验中测得的温度分布符合较好.1 实验分别进行了正三角形钝体燃烧器、流线体燃烧器和直流式燃烧器的燃烧实验.其喷口截面积均为16×32cm,结构如图1所示.燃烧器安装在燃烧实验炉头部,与之一起构成突扩通道燃烧室.实验主要设备是小型卧式热态试验台,燃烧室横截面积为0.35×0.5m~2.沿燃烧室轴线方向布置有11个测量孔.实验台配有专门的点火油系统.

An Experimental Study on a One-Dimensional Model for Pulverized Coal Flame Stabilization by a Bluff-Body

The bluff-body buener is widely used in power plant boilers in part of China's southern provinces. It is effective for burning low-grade coals with very good economic benefit. But the mecnanism of flame stabilization has not yet been explored. In order to investigate the flame stability when pulverized coal is burnt using a bluff-body, a one-dimensional model has been developed on the basis of experiments. It is assumed that the combustion channel behind the bluff-body is composed of a well stirred flow followed by a plug-flow combustor in series. The radiant heat transfer between coal-air flow and furnace wall has been taken into account. A parameter Nm is introduced to describe the turbulent mixing in the coal-air flow and the temperature rise process because of the preheating by recirculating hot flue gas. Numerical calculation shows that the temperature distributions predicted by the model are in conformity with those measured by experiment.