单系列辅机低负荷运行协调控制及优化  

Coordinated control and optimization for unit equipped with single-line auxiliaries during low load operation

作　　者：陈志刚[1] 刘百成 王田[1] 谈博[1] 曲志祥 李俊峰 赫胜杰 

机构地区：[1]西安热工研究院有限公司,陕西西安710032 [2]华能洛阳发电有限责任公司,河南洛阳471000

出　　处：《热力发电》2016年第11期120-124,共5页Thermal Power Generation

摘　　要：某配置单系列辅机的超临界燃煤发电机组投运后长期处于50%及以下负荷运行,而其存在的低负荷工况下控制精度低的特性难以满足机组协调控制要求,导致机组存在过热度、给水和主蒸汽压力波动大、引风机出力扰动大、一次调频负荷响应慢、机组经济性和安全性无法保证的问题.对此,本文提出改变磨煤机入口风量测量装置,完善炉膛负压控制和低负荷时降低一次风流量占比,变参数动态适配给水和过热度控制策略,增加一次调频阀位响应指令快动慢回,并对锅炉主控制器和低负荷前馈回路进行改造.优化改造后的低负荷170-200 MW（48%-57%）扰动试验结果表明,优化后的协调控制策略能满足机组升降负荷和稳态运行的需求.该控制策略对单系列辅机低负荷安全运行、电网深度调峰控制具有一定借鉴作用.A supercritical coal-fired power generating unit equipped with single-line auxiliaries ran at 50% load for a long time after being put into service, the poor control accuracy at low load makes the unit be un- able to satisfy the requirements of coordination control, and brings out several problems, such as the superheat temperature,large fluctuation of feedwater and main steam pressures,great disturbance of the induced draft fan, slow load response to the primary frequency regulation, unable to effectively guarantee the unit thermal efficiency and safety risk. To solve these problems, this paper puts forward a series of countermeasures, like modifying the mill inlet air flow measurement device, improving the furnace pressure control,reducing the primary air ratio during low load operation, dynamically adapting the feedwater and superheating temperature control strategy using variable parameter, adding the primary frequency regulation valve position response demand, and optimizing the boiler main control circuit and low load feed-forward loop. The low load 170-200 MW （48%-57%） varying load test results indicate that,the optimized coordination control can meet the unit＇s operation requirement during load increasing/descending process. This optimized control strategy has a certain reference for low load safe operation of units equipped with single line auxiliaries.

关 键 词：超临界机组 单系列配置辅机 低负荷运行 协调控制 优化改造 

分 类 号：TK323[动力工程及工程热物理—热能工程]