Design Type-selection And Optimization Operation Of Combustion System For (Ultra-) Supercritical Boiler

(Ultra-)supercritical power generation technology is a clean coal power generationtechnology which is of high efficiency and low pollution. And the technology and abilityin design, manufacture and operation of this boiler is continuously developing andconsummating in China. But combustion property of boiler is affected directly bycombustion mode selection and variation of coal with its capacity enlargement.Firstly, the mode selection analysis on coal pulverizer and combustion mode of(ultra-)supercritical boiler in service is done. Practice indicates cold primary air positivepressure direct firing type of pulverizing system equipped with medium speed mill andtangential combustion mode is disposed by (ultra-)supercritical boiler. Secondly,combined with the boiler overall layout and the properties of coal, the combustion modeselection scheme about (ultra-)supercritical boiler is drawm up. Then the combustionsimulation and performance test about ultra-supercritical boiler in Jingdezhen PowerPlant is done. Simulation shows the furnace temperature is rather high when walltangential firing is adopted, and combustion is completed. The calculation indicates theboiler efficiency is93.61%, the maximum output of coal-pulverizing system is70t/h, andthe unit consumption of coal pulverizer is7.70kW·h/t, all of the indexes are better thanthe performance guaranteed value. Finally, a new pattern tangential oval combustionmode applied to ultra-supercritical boiler is advanced. And layout optimization of direct-flow burner in tangential oval combustion is done based on the boiler parametersincluding thermal intensity and structure of furnace etc.in Jingdezhen Power Plant.Research shows the problem including aggravation of flue gas temperature atfurnace outlet and the limit of width to depth ratio can be effectively sovled by selectingcombustion system and combustion optimization. The results can provide scientificprogram for (ultra-)supercritical boiler combustion system design selection and supplydata support for boiler combustion optimization.