摘要
[目的]“双碳”目标下新型电力系统建设要求存量火电转向调峰运行,因此火电机组灵活运行下的安全性成为提升电力系统整体稳定性不可或缺的一环。其中,空气预热器是影响火电机组宽负荷运行能力的关键辅机设备,针对其由烟温波动与过量喷氨诱发的堵塞与腐蚀问题,开发回转式空气预热器积灰堵塞实时评估及安全状态监测模型至关重要。[方法]依托中国中部地区某600 MW和350 MW机组宽负荷运行监测大数据,建立了一种基于阻力系数的不同时间尺度逼近的空预器堵塞评估模型;进一步,以空预器出口烟气温度及冷端工作温度为监测指标,统计其在机组多个负荷段的参数超限比例。[结果]结果表明,机组处于39%调峰负荷下监测温度约有20%的超限概率;独立计算两指标下的堵塞风险相较以联合分布计算会一定程度低估其折损率。此外,通过两台机组数据的验证,堵塞评估模型可实现量化机组在空预器吹灰周期内(短期)和中长期的堵塞状态演化趋势。[结论]所提评估策略可应用于SCR脱硝系统、磨煤机等其他火电机组设备及系统,可量化机组调峰运行安全风险,指导火电机组高效、稳定地配合新型电力系统调度。
[Introduction] The realization of "dual carbon" goals in the construction of a new power system necessitates the transformation of existing thermal power plants to accommodate peak load operations.The safety of thermal power units during flexible operation is a critical element for enhancing the overall stability of the power system.Air preheater is the key auxiliary equipment that affects the wide-load operation capacity of thermal power units.This paper addresses the challenges associated with flue gas temperature fluctuations and blockage and corrosion induced by excessive ammonia injection.It is very important to develop a real-time assessment and safety status monitoring model for dust and blockage of rotary air preheaters.[Method] Based on the big data of wide-load operation monitoring of 600 MW and 350 MW units in central China,the paper developed a model for air preheater blockage assessment based on approximation of the resistance coefficients in the case of various time scales.Furthermore,the flue gas temperature at the outlet of the air preheater and the cold end working temperature were used as monitoring indicators to count the proportion of parameters exceeding the limit in multiple load sections of the unit.[Result] The results show that,at a peak regulation load of 39%,there is approximately a20% probability of temperature exceedance.In addition,the independent calculation of the blockage risk based on the two indicators may result in a certain degree of underestimation of its degradation rate compared to the calculation based on a joint distribution.Besides,with the verification of data from the two units,the method can quantify the short-term(within the soot-blowing cycle) and mid-and-long term evolution of the air preheater blockage.[Conclusion] This assessment strategy applies to other equipment and systems in thermal power plants,such as SCR denitrification systems and coal mills,providing a quantitative assessment of safety risks during peak load operation.It guides thermal power units to ef
作者
王志敏
黄骞
柳冠青
周勇
张楠
李诚
李水清
WANG Zhimin;HUANG Qian;LIU Guanqing;ZHOU Yong;ZHANG Nan;LI Cheng;LI Shuiqing(Key Laboratory of Thermal Science and Power Engineering of Ministry of Education,Department of Energy and Power Engineering,Tsinghua University,Beijing 100084,China;SPIC Power Plant Operation Technology(Beijing)Co.,Ltd.,Beijing 102209,China)
出处
《南方能源建设》
2024年第6期33-40,共8页
Southern Energy Construction
基金
国家重点研发计划项目“亚临界煤电机组深度灵活调峰关键技术及工程示范”(2023YFB4102900)。
关键词
火电机组
灵活调峰
空气预热器
堵塞
状态评估
thermal power
flexibility
air preheater
blockage
condition assessment
