为了解决大容量超超临界燃煤机组在低负荷工况热经济性明显下降的问题，本文提出了一种汽轮机补汽调节系统，即减少高压缸前段的通流面积并增加旁通补汽。基于MATLAB/Simulink仿真平台，搭建了某1000 MW超超临界燃煤机组的系统仿真模型和热力学分析模型，并分析了汽轮机的补汽率和补汽压比对机组热经济性的影响。结果表明，在汽轮机的补汽压比不变时，提高汽轮机的补汽率可以降低机组的发电煤耗率，且负荷越低节能效果越明显；在机组的负荷率为20%、补汽压比和补汽率分别为0.95和0.6时，采用汽轮机补汽调节系统可以使汽轮机进汽压力增加约6 MPa，机组发电煤耗率降低约20g·(kW·h)-1；以机组两个月的实际运行负荷为边界条件，机组的总煤耗量可以降低约1.8%。

In order to solve the problem that the thermal economy of large-capacity ultra-supercritical coal-fired units decreases significantly under low load conditions, this paper proposes a steam turbine supplementary steam regulate system, which reduces the flow area of the high-pressure cylinder front section and increases the bypass steam supplement. Based on the MATLAB/Simulink simulation platform, the system simulation model and thermodynamic analysis model of a 1000 MW ultra-supercritical coal-fired unit are built, and the influence of the supplementary steam rate and the supplementary steam pressure ratio of the steam turbine on the thermal economy of the unit is analyzed. The results show that, when the supplementary steam pressure ratio of the steam turbine is constant, increasing the supplementary steam rate of the stream turbine can reduce the coal consumption rate of the unit, and the lower the load, the more obvious the energy saving effect; when the load rate of the unit is 20 %, and the supplementary steam pressure ratio and the supplementary steam rate are 0.95 and 0.6, the steam turbine inlet pressure can be increased by about 6 MPa, and the coal consumption rate of the unit is reduced by about 20 g·(kW·h)-1; taking the actual operating load of the unit for two months as the boundary condition, the total coal consumption of the unit can be reduced by about 1.8 %.

国家重点研发计划 (2022YFB4100800)