350 MW超临界CFB锅炉热态启动耗油量大的问题分析和解决措施

Problem analysis and solution to heavy fuel consumption for 350 MW supercritical CFB during hot start-up

某350 MW超临界CFB锅炉热态启动耗油量大,经分析,主要是锅炉跳闸后冷却速率快且停止补水不及时,不能维持相对高的床温;炉内物料粒径和粗颗粒比重增加,严重偏离设计值等造成的流化、传热不良;流化风量增加造成启动点火时热损失增加等原因。对此针对性的采取控制合理的给水冷却流量,确定因物料改变后的流化风量,降低床压,有效的投煤燃烧方式保证床温上涨,及其启动点火阶段给水控制、设备缺陷消除等有效措施,耗油量大的问题得以有效控制。对于同类型超临界CFB锅炉的运行、燃烧调整等有借鉴意义。

In view of the heavy fuel consumption for 350 MW supercritical CFB during hot start-up, the factors of fast cooling rate and not timely stopping the water supply after the boiler trip are analyzed. Due to the reasons above, a relatively high bed temperature cannot be maintained. The fluidization and poor heat transfer caused by the increase of the particle size and the proportion of coarse particles in the furnace seriously deviated from the design value. Besides, increased fluidized air volume also results in increased heat loss during ignition. By taking a reasonable control of the water supply and cooling flow and confirming fluidized air and reducing bed pressure after the change of material flow, the bed temperature rise and fuel consumption are controlled effectively, and then the ignition initial phase of feed-water flow and eliminate equipment defects can be handled, and the problem of large fuel consumption can be effectively controlled. For the same type of supercritical CFB boiler operation, the combustion adjustments have a good reference.