抽汽供热机组RB控制逻辑优化研究  

Research on Optimization of RB Control Logic for Extraction Heating Turbine Unit

作　　者：吴水龙 曹鹏飞 杨子江 WU Shuilong;CAO Pengfei;YANG Zijiang(Dezhou Power Plant,Huaneng International Power Co.,Ltd.,Dezhou 253024,China;College of Electrical Engineering and Automation,Shandong University of Science and Technology,Qingdao 266590,China)

机构地区：[1]华能国际电力股份有限公司德州电厂,山东德州253024 [2]山东科技大学电气与自动化工程学院,山东青岛266590

出　　处：《自动化仪表》2020年第3期58-61,共4页Process Automation Instrumentation

基　　金：山东省自然科学基金资助项目(ZR2017PF002)。

摘　　要：辅机故障减负荷(RB)控制在机组发生部分主要辅机故障跳闸时,可将机组负荷快速降到当前辅机实际所能达到的相应出力,并调节机组参数至允许范围内,以保障机组持续运行、避免非停事故发生。然而,大量纯凝机组在完成供热或工业供汽改造后,并没有对其RB控制逻辑进行相应修改,导致主要辅机故障时,机组实际负荷仍然低于当前辅机所能达到的相应出力。这进而会导致RB控制拒动,增加了机组非停风险。为了解决上述问题,在分析供汽改造后RB控制逻辑无法触发的原因基础上,首次提出了有效的机组发电负荷实时预测方法。通过采用预测负荷取代机组当前实际负荷,修正了RB控制逻辑触发的判定条件,确保RB控制能够及时正确触发。该方法具有适用广泛、抗干扰性强等优点。When a part of the main auxiliary machineries trips,the maximal generated active power of power generation unit would be lower than its desired load,and the runback control(i.e.RB)is to reduce the unit output to its capable level in coordinate with all running auxiliary machineries supporting.RB control can keep the power generation unit running normally,and is the most important prevention for the abrupt stop accidents.However,RB logic has not been modified timely in practice when there was industrial steam extraction from the power generation units.Hence,if there exists main auxiliary machineries tripped,RB control cannot be triggered most likely,due to the measured generated active power still small than the main auxiliary machineries supporting.By analyzing the root causes of this problem,an approach of predicting the unit load in real-time is first proposed.The predicted load is used to substitute the actual output to judging whether the RB control is to trigger or no.With this trick,the problem of serious deviation between generated active power and main auxiliary machineries supporting has been modified,which ensures the RB control triggering correctly.The proposed approach is robust to disturbances and has applied in heating extraction units.

关 键 词：冷凝机组 供汽改造 RB控制 发电负荷预测 能量守恒 蒸汽能量 过热蒸汽流量 过热蒸汽焓值 

分 类 号：TH-89[机械工程]