电站锅炉SCR脱硝系统联合运行优化模型

Optimization model for combined operation of SCR denitration system in utility boiler

燃煤锅炉采用选择性催化还原(SCR)脱硝系统会带来厂用电增加及还原剂消耗,增加了运行成本。为使联合运行成本最优,本文在考虑SCR脱硝系统运行成本和锅炉燃煤成本的基础上,结合机组负荷、总给煤量、总风量、一次风压、二次风量、燃尽风量和喷氨量等参数之间的关系,建立了电站锅炉SCR脱硝系统联合运行成本模型,利用粒子群(PSO)算法对一次风压、二次风量、燃尽风量和喷氨量等可调运行参数进行优化,得到不同工况下各参数的最优值。并且采用某1 000 MW发电机组实际运行数据进行模型仿真,结果表明:所建模型具有较好的预测精度和较强的泛化能力,通过优化后机组的联合运行成本可降低3%~5%。

Applying selective catalytic reduction (SCR) flue gas denitration system in coal-fired boiler will increase the auxiliary power and reducing agent consumption, and increase the operation cost. To reduce the operation cost, this paper establishes an operation cost model for the boiler and SCR denitration system by using the parameters including the unit load, total coal feed rate, total air volume, primary air pressure, secondary air rate, over fire air rate and ammonia injection rate, on the basis of considering the operation cost of the SCR denitration system and fuel cost of the boiler. The particle swam optimization (PSO) algorithm is proposed to optimize the adjustable parameters such as the primary air pressure, secondary air rate, over fire air rate and the ammonia injection rate, thus the optimal values of each parameter under different conditions are obtained. Moreover, simulation experiments were carried out by using the operation data of a 1 000 MW thermal power plant, and the results show that, the established model has good prediction precision and strong generalization ability, the combined operation cost of the unit after optimization can be reduced by 3%~5%.