For boiler 5 in Matou General Power Plant, a leancoalfired boiler with exhausted air coalpowder feeding, the thermal efficiency at rated load and the ability of stable combustion at low load are significantly improved by using thick thin separation technology to transform double volute burners into radial thick thin vortex burners.
The optimization of adopting combustionstabilizing body and central air (<4%) can make the tunable rich/lean berner to really realize the high efficient combustion, stable combustion at low load, and low emission of NO_x.
To improve the ability of in depth peak load cycling of a 200 MW boiler,according to the synthetic analysis on the results of investigation ,the technology of direct firing of adjustable coal powder gradation and the technology of adjustable scope of back flow region developed by Zhejiang University are used to modify the burners for stable combustion at low load.
The reasonable shape of bluff-body has been found and applied to the burners of a 410t/h boiler in Huozhou Power Plant, Shanxi Province, and its good performance of stable combustion under low load has been confirmed.
In addition,the application of this technology was proposed in this paper and the operation and test result shows that the technology can meet the requirement of oil saving during the periods of boiler starting,stopping,stable combustion under low load for the lignite-fired units.
After analysis of the problems,such as poor capability of low load stable combustion,main & reheat steam temperature low with too much deviation,exhaustion temperature high,hot air temperature high,serious slagging in furnace,flame-out etc,which universally exist with M419 Boiler,Comprehensive improvement measures are studied out and implemented and great effects are achieved.