火电机组快速变负荷的锅炉动态响应分析
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摘要
针对锅炉内典型烟气-金属-蒸汽换热器的动态换热过程,采用单一变量控制法,分析受热面对质量流量阶跃的动态响应时间,并建立锅炉动态模型,在不同边界条件发生阶跃变化时,计算各受热面的动态响应特性。结果表明:动态响应时间随并联管长度及壁厚尺寸的增加而增加;随入口工质温度、热负荷以及质量流速的增加而缩短。在质量流量发生-10%阶跃扰动时,省煤器对扰动的响应速度最慢,响应时间约220 s;水冷壁低温段及水平低温再热器次之,高温受热面(如末级过热器、末级再热器等)响应速度最快,响应时间约10 s,为提高机组变负荷灵活性,缩短锅炉对负荷响应时间,可通过旁路部分响应速率慢的受热面来实现。
Based on the dynamic heat transfer process of typical flue gas-metal-steam heat exchanger in boiler,the single-variable control method was adopted to analyze the heat surface′s dynamic response time to mass flow steps.The results show that the dynamic response time increases as the length of connecting surface and wall thickness increase,but decreases as the inlet working fluid temperature,heat load,and mass flow rate increase.Meanwhile,by establishing a practical boiler dynamic model,the dynamic response characteristics of each heating surface were calculated when step changes occur under different boundary conditions.The results indicate that when a-10% step disturbance occurs in the mass flow,the response speed of the economizer to disturbance is the slowest with a response time of 220 seconds at a maximum/(220 s),followed by low temperature section of water cold wall and horizontal low temperature reheater.However,the response speed of high temperature heating surfaces(such as last stage superheater,last stage reheater,etc.) to disturbance is the fastest with a response time of 10 seconds/(10 s).To improve the variable-loading flexibility of the units and shorten the response time of the boiler to the load,bypassing the heating surface with slow response speed is an effective approach.
Based on the dynamic heat transfer process of typical flue gas-metal-steam heat exchanger in boiler,the single-variable control method was adopted to analyze the heat surface′s dynamic response time to mass flow steps.The results show that the dynamic response time increases as the length of connecting surface and wall thickness increase,but decreases as the inlet working fluid temperature,heat load,and mass flow rate increase.Meanwhile,by establishing a practical boiler dynamic model,the dynamic response characteristics of each heating surface were calculated when step changes occur under different boundary conditions.The results indicate that when a-10% step disturbance occurs in the mass flow,the response speed of the economizer to disturbance is the slowest with a response time of 220 seconds at a maximum/(220 s),followed by low temperature section of water cold wall and horizontal low temperature reheater.However,the response speed of high temperature heating surfaces(such as last stage superheater,last stage reheater,etc.) to disturbance is the fastest with a response time of 10 seconds/(10 s).To improve the variable-loading flexibility of the units and shorten the response time of the boiler to the load,bypassing the heating surface with slow response speed is an effective approach.
引文
[1] 陈国平,李明节,许涛,等.关于新能源发展的技术瓶颈研究[J].中国电机工程学报,2017,37(1):20-26.CHEN Guo-ping,LI Ming-jie,Xu Tao,et al.Study on technical bottleneck of new energy development[J].Proceedings of the CSEE,2017,37(1):20-26.
[2] 舒印彪,张智刚,郭剑波,等.新能源消纳关键因素分析及解决措施研究[J].中国电机工程学报,2017,37(1):1-8.SHU Yin-biao,ZHANG Zhi-gang,GUO Jian-bo,et al.Study on key factors and solution of renewable energy accommodation[J].Proceedings of the CSEE,2017,37(1):1-8.
[3] 徐飞,陈磊,金和平,等.抽水蓄能电站与风电的联合优化运行建模及应用分析[J].电力系统自动化,2013,37(1):149-154.XU Fei,CHEN Lei,JIN He-ping,et al.Modeling and application analysis of optimal joint operation of pumped storage power station and wind power[J].Automation of Electric Power Systems,2013,37(1):149-154.
[4] 刘芳,潘毅,杨军峰,等.风电-火电-抽水蓄能联合优化机组组合模型[J].中国电机工程学报,2015,35(4):766-775.LIU Fang,Pan YI,YANG Jun-feng,et al.Unit commit-ment model for combined optimization of wind power-thermal power-pumped storage hydro[J].Proceedings of the CSEE,2015,35(4):766-775.
[5] 吴玉庭,任楠,马重芳.熔融盐显热蓄热技术的研究与应用进展[J].储能科学与技术,2013,2(6):586-592.WU Yu-ting,REN Nan,MA Chong-fang.Research and application of molten salts for sensible heat storage [J].Energy Storage Science and Technology,2013,2(6):586-592.
[6] 路阳,彭国伟,王智平,等.熔融盐相变储热材料的研究现状及发展趋势[J].材料导报,2011,25(11):38-42.LU Yang,PENG Guo-wei,WANG Zhi-ping,et al.A review on research for molten salt as a phase change material[J].Materials Review,2011,25(11):38-42.
[7] 于翔.300 MW直流锅炉管内工质动态特性的建模与仿真研究[D].南京:东南大学,2006.YU Xiang.Modeling and simulation of the working fluid dynamics in a 300 MW once-through boiler[D].Nanjing:Southeast University,2006.
[8] 张威,闫凯,王欢,等.超超临界二次再热直流锅炉水冷壁水动力特性研究[J].热能动力工程,2016,31(8):75-80.ZHANG Wei,YAN Kai,WANG Huan,et al.Research on thermal hydrodynamic performance of water wall pipes for ultra-supercritical double reheat once-through boiler[J].Journal of Engineering for Thermal Energy and Power,2016,31(8):75-80.
[9] 刘远鹏.超临界压力锅炉汽水系统分布参数动态数学模型[D].重庆:重庆大学,2005.LIU Yuan-peng.Dynamic mathematical model of distributed parameter for steam-water system of supercritical pressure boiler[D].Chongqing:Chongqing University,2005.
[10] 王伟,任挺进,高琪瑞,等.直流锅炉蒸发区域的数学模型及其仿真[J].清华大学学报(自然科学版),2001:41(10):105-108.WANG Wei,REN Ting-jin,Gao Qi-rui,et al.Mathematical model and simulation of the evaporating surface in a once-through boiler[J] J Tsinghua University,2001:41(10):105-108.
[11] 杨世铭,陶文铨.传热学[M].4版.北京:高等教育出版社,2006.YANG Shi-ming,TAO Wen-quan.Heat transfer[M].4th ed.Beijing:Higher Education Press,2006.
[12] 章臣樾.锅炉动态特性及其数学模型[M].北京:水利电力出版社,1987.ZHANG Chen-yue.Dynamic characteristics and mathe-matic model of boilers[M].Beijing:1987:Resources and Electric Power Press,1987.
[13] 王泽宁,周强泰,孔红军.单相受热管集中参数简化模型的讨论[J].中国电机工程学报,1993,13(04):44-51.WANG Ze-ning,ZHOU Qiang-tai,KONG Hong-jun.Investigation on the simplified lumped-parameter model of single-phase heated tubes[J].Proceedings of the CSEE,1993,13(04):44-51.
[14] 吕子安,李天铎.单相介质受热管集中参数模型建模方法的改进[J].系统仿真学报,1993,5(1):1-8.LYU Zi-an,LI Tian-duo.The improued lumped-parameter model of monophase fluid heated tubes[J].Journal of System Simulation,1993,5(1):1-8.
[15] 王广军,章臣樾.锅炉动态模型中总压能平衡方程及受热面金属的当量质量[J].动力工程,1989,9(4):29-32.WANG Guang-jun,ZHANG Chen-yue.Heat balance equations and the equivalent mass of the heated metal in boiler dynamic models[J].Power Engineering,1989,9(4):29-32.
[16] 陶文铨.数值传热学(第二版)[M].西安:西安交通大学出版社,2001.TAO Wen-quan.Numerical heat transfer[M].2th ed.Xi′an:Xi′an Jiaotong University Press,2001.
[2] 舒印彪,张智刚,郭剑波,等.新能源消纳关键因素分析及解决措施研究[J].中国电机工程学报,2017,37(1):1-8.SHU Yin-biao,ZHANG Zhi-gang,GUO Jian-bo,et al.Study on key factors and solution of renewable energy accommodation[J].Proceedings of the CSEE,2017,37(1):1-8.
[3] 徐飞,陈磊,金和平,等.抽水蓄能电站与风电的联合优化运行建模及应用分析[J].电力系统自动化,2013,37(1):149-154.XU Fei,CHEN Lei,JIN He-ping,et al.Modeling and application analysis of optimal joint operation of pumped storage power station and wind power[J].Automation of Electric Power Systems,2013,37(1):149-154.
[4] 刘芳,潘毅,杨军峰,等.风电-火电-抽水蓄能联合优化机组组合模型[J].中国电机工程学报,2015,35(4):766-775.LIU Fang,Pan YI,YANG Jun-feng,et al.Unit commit-ment model for combined optimization of wind power-thermal power-pumped storage hydro[J].Proceedings of the CSEE,2015,35(4):766-775.
[5] 吴玉庭,任楠,马重芳.熔融盐显热蓄热技术的研究与应用进展[J].储能科学与技术,2013,2(6):586-592.WU Yu-ting,REN Nan,MA Chong-fang.Research and application of molten salts for sensible heat storage [J].Energy Storage Science and Technology,2013,2(6):586-592.
[6] 路阳,彭国伟,王智平,等.熔融盐相变储热材料的研究现状及发展趋势[J].材料导报,2011,25(11):38-42.LU Yang,PENG Guo-wei,WANG Zhi-ping,et al.A review on research for molten salt as a phase change material[J].Materials Review,2011,25(11):38-42.
[7] 于翔.300 MW直流锅炉管内工质动态特性的建模与仿真研究[D].南京:东南大学,2006.YU Xiang.Modeling and simulation of the working fluid dynamics in a 300 MW once-through boiler[D].Nanjing:Southeast University,2006.
[8] 张威,闫凯,王欢,等.超超临界二次再热直流锅炉水冷壁水动力特性研究[J].热能动力工程,2016,31(8):75-80.ZHANG Wei,YAN Kai,WANG Huan,et al.Research on thermal hydrodynamic performance of water wall pipes for ultra-supercritical double reheat once-through boiler[J].Journal of Engineering for Thermal Energy and Power,2016,31(8):75-80.
[9] 刘远鹏.超临界压力锅炉汽水系统分布参数动态数学模型[D].重庆:重庆大学,2005.LIU Yuan-peng.Dynamic mathematical model of distributed parameter for steam-water system of supercritical pressure boiler[D].Chongqing:Chongqing University,2005.
[10] 王伟,任挺进,高琪瑞,等.直流锅炉蒸发区域的数学模型及其仿真[J].清华大学学报(自然科学版),2001:41(10):105-108.WANG Wei,REN Ting-jin,Gao Qi-rui,et al.Mathematical model and simulation of the evaporating surface in a once-through boiler[J] J Tsinghua University,2001:41(10):105-108.
[11] 杨世铭,陶文铨.传热学[M].4版.北京:高等教育出版社,2006.YANG Shi-ming,TAO Wen-quan.Heat transfer[M].4th ed.Beijing:Higher Education Press,2006.
[12] 章臣樾.锅炉动态特性及其数学模型[M].北京:水利电力出版社,1987.ZHANG Chen-yue.Dynamic characteristics and mathe-matic model of boilers[M].Beijing:1987:Resources and Electric Power Press,1987.
[13] 王泽宁,周强泰,孔红军.单相受热管集中参数简化模型的讨论[J].中国电机工程学报,1993,13(04):44-51.WANG Ze-ning,ZHOU Qiang-tai,KONG Hong-jun.Investigation on the simplified lumped-parameter model of single-phase heated tubes[J].Proceedings of the CSEE,1993,13(04):44-51.
[14] 吕子安,李天铎.单相介质受热管集中参数模型建模方法的改进[J].系统仿真学报,1993,5(1):1-8.LYU Zi-an,LI Tian-duo.The improued lumped-parameter model of monophase fluid heated tubes[J].Journal of System Simulation,1993,5(1):1-8.
[15] 王广军,章臣樾.锅炉动态模型中总压能平衡方程及受热面金属的当量质量[J].动力工程,1989,9(4):29-32.WANG Guang-jun,ZHANG Chen-yue.Heat balance equations and the equivalent mass of the heated metal in boiler dynamic models[J].Power Engineering,1989,9(4):29-32.
[16] 陶文铨.数值传热学(第二版)[M].西安:西安交通大学出版社,2001.TAO Wen-quan.Numerical heat transfer[M].2th ed.Xi′an:Xi′an Jiaotong University Press,2001.