State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an Jiaotong University

设置省煤器烟气旁路系统是提高燃煤机组脱硝系统入口烟气温度、实现全工况脱硝的有效途径。 为分析燃煤机组频繁变负荷过程的脱硝经济性,本研究建立了某 660 MW 超超临界燃煤发电机组动态模型及 SCR 脱硝系统动态模型,研究了燃煤机组在 50% ~100%THA 升负荷过程的尿素成本、NOx排放环境成本和燃煤成本。 结果表明:在变负荷过程中开启省煤器烟气旁路挡板时,燃煤成本的变化最大,总成本有一定的增加;在 50% ~75%THA 升负荷过程中,烟气旁路挡板开度分别为 5%和 10%时,燃煤成本分别增加了 600 元和 1 200 元,尿素成本分别减少了442.48元和 554.89 元,而 NOx排放环境成本变化较小,仅为 62.22 元和 63.19 元;在 75% ~ 100%THA 升负荷过程中,燃煤成本分别增加了 1 800 元和 2 300 元,而尿素成本和 NOx排放环境成本的变化量较小,因此不建议开启烟气旁路挡板。

Setting up an economizer flue gas bypass system is an effective approach to increase the inletflue gas temperature of the denitration system in a coal-fired power plant and maintain high De-NOx ef⁃ficiency under all working conditions. In order to analyze the economy of the denitration system in acoal-fired power plant during frequent load cycling processes,the dynamic models of a 660 MW ultrasupercritical coal-fired power plant and the SCR system are developed. Then,the cost of urea,the envi⁃ronmental cost of NOx emission and the cost of coal are obtained and compared under different flue gasbypass baffle opening during the loading up processes from 50%THA to 100%THA. The results showthat the change value of coal cost is the largest,and the total cost has a certain increase when the econ⁃omizer flue gas bypass baffle is opened during the load cycling processes. When the flue gas bypass baf⁃fle opening is 5% and 10%,the cost of coal increases by ￥ 600 and ￥ 1 200 respectively during theloading up processes from 50% to 75%THA. Meanwhile,the cost of urea decreased by ￥ 442.48 and￥ 554.89 respectively,while the environmental cost of NOx emission changed less,only ￥ 62.22 and￥ 63.19. Moreover,the cost of coal increased by ￥ 1 800 and ￥ 2 300 respectively during the loadingup processes from 75% to 100%THA,and the amounts of change in urea cost and NOx emission envi⁃ronmental cost were little. Therefore,it is not recommended for coal-fired power plant to open the fluegas baffle during the loading up processes from 75% to 100%THA.

国家自然科学基金(52022079)

高伟, 刘明, 赵永亮, 等. 采用烟气旁路的燃煤机组脱硝系统变负荷过程的经济性分析[J]. 能源环境保护, 2023, 37(1): 13-20.

GAO Wei, LIU Ming, ZHAO Yongliang, et al. Economic analysis of denitration system in a coal-fired power plantwith flue gas bypass during load cycling processes[J]. Energy Environmental Protection, 2023, 37(1): 13-20.