中文摘要：

为了解决低负荷运行时燃煤发电机组脱硝效果差及热经济性低的问题,以某660 MW超临界机组为研究对象,基于GSE仿真平台搭建锅炉汽轮机耦合模型。在此模型基础上,提出以屏式过热器出口蒸汽引射汽轮机1级抽汽,通过蒸汽喷射器的混合蒸汽作为新增0号高压加热器的汽源以加热给水,并嵌入蒸汽喷射器性能模型,计算得到了不同的喷射器引射比对脱硝效率、机组热经济性以及变工况性能的影响。研究表明：设计负荷为50%负荷时,最佳设计引射比为0.56（对应的设计给水温升为30℃）,此时系统节煤0.52g·（kW·h）^-1,脱硝效率提高13.29%;综合考虑喷射器的运行稳定性和机组的热经济性,建议优化后的系统在45%～90%负荷范围内运行,此时可获得较佳的节能减排效果。

英文摘要：

To improve the denitration effect and the thermodynamic performance of generator unit under low loads,a new feed water heating system coupled with steam ejector is required.A 660 MW coal-burning supercritical unit is taken as the research object.A boiler/steam turbine coupled model is established based on the simulation platform of GSE.On the basis of this model,the steam ejector and the new No.0high-pressure heater are embedded in by a selfprogramming model.The platen super-heater outlet steam is the primary steam and the steam from No.1steam extraction is the induced steam,then the mixture steam flows into the No.0high-pressure heater to heat the water.The effects of entrainment ratio on the denitration efficiency,the thermal efficiency and the performance under variable working conditions are investigated.Results show that when the design load of the steam ejector is 50%load condition,the optimal design entrainment ratio is 0.56 and the temperature of feed water rises by 30℃;the standard coal consumption rate is decreased by 0.52g·（kW·h）-1 and the denitration efficiencyis increased by 13.29%.Considering the running stability of the ejector and the thermal efficiency of the unit,the optimized system is suggested to operate in the range of 45%-90%load to obtain the best energy-saving and emission reduction effect and thermodynamic performance.