双通道浓淡与乏气OFA组合煤粉燃烧器的试验研究

Experimental Study of a Dual Channel Bias and Exhaust Gas OFA Combined Pulverized Coal Burner

为解决某电厂100 t/h四角切圆煤粉炉燃烧效率低、燃烧不稳定的问题,采用双通道浓淡与乏气OFA(燃尽风)组合煤粉燃烧器进行技术改造,其特点为上一次风双通道上下浓淡、下一次风水平浓淡并且集中布置,乏气通过OFA送入炉内。冷态结果表明;该改造方案炉内气流充满度好,气流量不偏斜刷墙;一次风喷口有明显的回流区,并随着腰部风开度的增大向炉膛中心移动,回流区半径减小;热态测试结果表明:热效率提高了3个百分点,50%低负荷稳燃,NOx排放量为260 mg/m3(折算到氧量6%)。

To solve the problems such as a low combustion efficiency and unsable combustion in a 100 t/h tangential pulverized coal-fired boiler in a power plant,dual-channel bias and exhaust gas OFA combined pulverized coal burners were used to perform a reconstruction,featuring a bias in the air aupply in the air supply through a dual channel between the upper and lower at the previous time followed by a bias in the horizontal direction,a centralized arrangement and the exhaust gas being fed into the furnance by OFA.The cold-state test results show that the air flow inside the furnance reconstructed has a good filling degree and never be oblique to sweep the walls.The primary air spout outlet has a marked return flow zone and shifts to the center of the furnance with an increase of the opening degree of the waist-elevated air.In this connection,the radius of the return flow zone also decreases.The hot-state test results show that the thermal efficiency increases by 3 percentage points,assuming a stable combustion at a low load of 50% and the NOx emissions totaling 260 mg/m3(converted to an oxygen content of 6%).