燃煤电站锅炉总风量跟随负荷控制理念分析  

Analysis of control of total air flowrate following load demand for coal-fired utility boilers

作　　者：周怀春 范海鸿 赵钧 刘尧平 程超[1] 曾雄伟[1] 唐文 刘兴[6] 谭厚章[6] ZHOU Huaichun;FAN Haihong;ZHAO Jun;LIU Yaoping;CHENG Chao;ZENG Xiongwei;TANG Wen;LIU Xing;TAN Houzhang(Key Laboratory of Condition Monitoring and Control for Power Plant Equipment,Ministry of Education (North China Electric Power University), Beijing100026,China;School of Energy and Power Engineering,Northeast Electric Power University,Jilin132012,China;Suzhou Jijie Power Technology Co.,Ltd.,Suzhou215011,China;Hubei Huadian Xiangyang Power Generation Co.,Ltd.,Xiangyang441141,China;Jiangsu Xinao Clean Energy Developments Ltd.,Nanjing210019,China;School of Energy and Power Engineering,Xi'an Jiaotong University,Xi'an710049,China)

机构地区：[1]电站设备状态监测与控制教育部重点实验室(华北电力大学),北京100026 [2]东北电力大学能源与动力工程学院,吉林吉林132012 [3]苏州吉杰电力科技有限公司,江苏苏州215011 [4]湖北华电襄阳发电有限责任公司,湖北襄阳441141 [5]江苏新奥能源发展有限公司,江苏南京210019 [6]西安交通大学能源与动力工程学院,陕西西安710049

出　　处：《洁净煤技术》2019年第2期18-24,共7页Clean Coal Technology

基　　金：国家重点研发计划资助项目(2017YFB0601900)

摘　　要：传统锅炉燃烧风量基于风、煤配比的概念,根据燃料量进行前馈粗调,再基于排烟氧含量的偏差进行反馈细调,燃料的调节会作用到风量的控制。智能发电技术的发展需要对现有燃烧控制的基本方法加以创新。燃煤发电机组控制的本质是负荷控制,即根据负荷指令控制从燃料化学能释放到汽轮发电机做功发电的各个能量转化环节。笔者分析了不同煤种燃烧产生相同的热量(对应大致相同的能量水平以及机组的发电功率)所需的理论空气量基本不变,该结论与目前国内外相关权威技术著作中的结论相符。因此提出用"风碳比"的概念代替"风煤比",即一定空气量与完全燃烧的碳量的比值,"风碳比"(质量比)约为11. 5,该值对不同煤种大致均为常数。并进一步提出了空热当量的概念,即在受限空间(炉膛)内任何煤种连续稳定燃烧每千克空气释放的热量,约为定数3. 01 MJ/kg air。在此基础上,提出应主要根据负荷的变化对锅炉总送风量进行控制,相同负荷下的总送风量控制可基本忽略燃料变化的影响。锅炉燃用煤种改变后,若锅炉效率下降,需燃料在炉内产生更多的热量,因而需增加锅炉送风量。本文的风量控制理念已在一台300 MW燃煤四角切圆燃烧发电机组上得到了成功应用,从2017年8月投运到现在,投入率超过80%,为实施风、煤独立解耦锅炉燃烧控制新策略奠定了基础。The traditional boiler combustion air flowrate control is based on the concept of air to coal ratio,and the feedforward roughly adjustment is made according to the fuel flowrate,and the fine adjustment is made according to the deviation of the oxygen content in the flue gas.The adjustment of fuel flowrate will affect the control of air flowrate.The development of smart power generation technology needs to innovate the existing basic methods of existing combustion control.The essence of coal-fired generation unit control is load control,that is,the energy conversion stages should be adjusted according to the load demand from the release of chemical energy in fuel combustion to the power generation of turbo-generator.The theoretical air volume required for different kinds of coal in combustion to produce the same amount of heat (corresponding to roughly the same energy level and power output of the unit) was basically unchanged,which was consistent with the conclusions in the relevant authoritative technical works.Therefore,the concept of "air-carbon ratio" was proposed to replace "air-coal ratio",that is,the ratio of a certain mass of air to a certain mass of carbon in complete combustion,which is about 11.5 (mass ratio),being roughly constant for different types of coal.The concept of air-heat equivalent is further put forward,which means that the heat released by any kind of coal burning steadily and continuously per kilogram of air in a confined space (furnace) is approximately equal to a constant value of 3.01 MJ/kg air.On this basis,it is proposed that the total air flowrate rate into a boiler should be controlled mainly according to the change of load demand,and the influence of fuel kind changes can be neglected in the total air flowrate control under the same load level.If the efficiency of boiler decreased as the change of coal kind burned in the boiler,more heat would be generated by the fuel in the furnace,and the air flowrate of the boiler should be increased,and vice versa.The new concept of air flowr

关 键 词：燃煤电站 锅炉 风量 火电机组 煤燃烧 燃烧控制 

分 类 号：TK323[动力工程及工程热物理—热能工程] TM621[电气工程—电力系统及自动化]