高水分低热值褐煤等离子体点火试验研究

Experimental study on plasma ignition technology of lignite with high moisture and low calorific value

针对φ813 mm×12 mm的煤粉管道,搭建了1:1尺寸的热态试验台,采用神华胜利发电厂超超临界660 MW机组燃用的高水分低热值褐煤,对新型偏置浓缩等离子体燃烧器的点火性能进行了试验研究。结果表明,该燃烧器在与工程现场实际工况基本一致的条件下实现了全水分36.1%的褐煤等离子体点火。同时,利用单因素变量试验方法,研究了一次风速、煤粉质量分数、一次风氧量、等离子体发生器功率等关键参数对点火性能的影响规律,得到各关键参数对燃烧器点火性能敏感性的影响次序为一次风温度、一次风氧量、一次风速、煤粉质量分数以及发生器功率。在机组冷炉启动时,保证其他因素满足条件的前提下,应尽量提高一次风温度,以提高等离子体燃烧器的点火性能。

For pulverized coal pipeline with scale of φ813 mm×12 mm, a 1:1 hot state test rig was built up. Experimentally study on ignition performance of a new bias concentrated plasma burner was carried out by using high moisture and low calorific value lignite fired on ultra supercritical 660 MW unit in Shenhua Shengli Power Plant. The test results show that, when the burner is under the condition that is basically consistent with the actual working conditions of the project site, plasma ignition for lignite with total moisture content of 36.1% is realized. At the same time, the influence law of key parameters such as primary air speed, pulverized coal mass fraction, primary air oxygen content and plasma generator power on ignition performance are studied by using single factor variable test method. It is obtained that the order of influence of key parameters on the sensitivity of burner ignition performance is primary air temperature, primary air oxygen content, primary air speed, pulverized coal mass fraction and generator power. On the premise of ensuring that other factors meet the conditions during the start-up of the cold furnace of the unit, the primary air temperature should be increased as much as possible to improve the ignition performance of the plasma burner.