某600MW机组锅炉结焦原因分析及预警软件开发应用

Cause analysis for coking in a 600MW unit boiler and the development and application of the pre-warning software

以某600 MW机组前后墙对冲燃烧锅炉为对象,针对其掺烧劣质煤出现的屏式受热面底部结焦问题,对焦块进行了SEM、XRD分析,对煤灰成分、灰熔点进行了测试,认为低灰熔点煤掺配比例不当是导致结焦的主要原因,并从精准配煤掺烧的角度提出解决方案。根据不同混煤的测试数据建立了灰熔点蚁群前馈神经网络预测模型,通过与现场测量的屏底烟温进行比较,获得了不同混煤的最大掺配比例曲线。同时,开发了电站锅炉结焦预警软件平台,在该平台的指导下,运行人员根据不同的负荷,最高已经将掺烧比例由原来的15%~20%提高至40%以上,应用效果良好。

In this paper,a 600 MW swirl-opposed coal-fired boiler is taken as an object to carry out research on the coking problem occurs at the bottom of the screen when the low-quality coal is burned.SEM and XRD analysis of the coke blocks were carried out and the composition of coal ash and ash melting point were tested.It pointed out that,the improper blending ratio of low ash melting point coal was the main reason for coking,and a solution was proposed from the perspective of precise coal blending and burning.Based on the data of different coal blends,the ash melting point prediction model of ACO-BP neural network was established.By comparing with the on-site measured flue gas temperature at the screen bottom,the maximum blending ratio curves of different coal blends were obtained to guide the operation adjustment work to gain the maximum economic benefits on the premise of ensuring safety.Moreover,a pre-warning software platform for utility boiler coking has been developed for timely and accurate adjustments operation,which has been used for more than a year and obtained good application results.