300MW机组厂级供热优化调度方式及性能分析

Heating Supply Optimization and Performance Analysis with Plant-level for 300MW Cogeneration Unit

从厂级角度优化机组的供热调度方式能够提升其深度调峰能力和盈利能力。以厂级两台300MW供热机组为例,利用Ebsilon软件建立了抽凝工况和低压缸零出力工况机组的数学模型,分析了机组的热力性能、调峰性能和经济性能。提出了5种厂级供热调度方式,研究了各调度方式下厂级的深度调峰能力和净收益;提出了串联梯级、并联平级供热系统,对比了二者对厂级净收益的影响。结果表明,供热量一定时,两台机组“双切缸模式”运行时,厂级发电功率最小,深度调峰能力最强;当供热负荷低于600MW时,两台机组“双切缸”模式运行时净收益最高;当供热负荷高于600MW时,“双抽凝”或“切缸+抽凝”模式运行时净收益最高;在厂级700MW供热负荷下,串联梯级供热系统的厂级净收益高于并联平级供热系统。

Optimizing the heating supplied regulation modes from the view of plant-level can improve the depth peak regulation ability and profitability of cogeneration unit.Taking a cogeneration plant with two 300MW units as an example,the Ebslion models of the unit with extraction steam heating mode(ESHM)and low pressure cylinder near zero output mode(LPCNZM)were established,the performances were analyzed from three dimensions of thermodynamic,peak load regulation and economy.The manuscript proposed five kinds of heating supplied regulation modes from plant-level,and investigated their depth peak regulation abilities and net profits.The series cascade and parallel horizontal heating systems were also evaluated based on the net profit of the whole plant.The results show that the power generation is the smallest and the depth peak regulation ability is the strongest when the two units both run in'double-LPCNZM mode'.As the heating load is lower than 600MW,the two units operating in'double-LPCNZM mode'possess the highest profit.However,as the heating load is higher than 600MW,'double-ESHM mode'or'LPCNZM-ESHM mode'has the highest profit.The series cascade heating system is better than the parallel horizontal heating system corresponding to 700MW of heating load.