摘要
二次再热机组流程复杂,惯性较大,其一次调频特性对电厂的运行稳定性、灵活性影响较大。以GSE仿真平台为基础,采用JTopmeret模块和自定义程序相结合的形式,建立了超超临界二次再热汽轮机的仿真模型与一次调频模型,并对此模型进行了精度校验。在此基础上,研究了二次再热机组参与一次调频过程中的热力参数响应特性,分析了负荷阶跃幅度、调速不等率对二次再热机组一次调频特性的影响。结果表明:当机组的负载功率增加时,二次再热机组一次调频控制系统开始动作,在动态调节过程中,实时频率小于50Hz,在达到稳态后,一、二次再热蒸汽的流量、压力变化相对值大于主蒸汽流量、压力变化相对值。在二次再热机组一次调频过程中,频率的动态超调量随负荷阶跃幅度的增大而增大,随调速不等率减小而增大。频率的调节时间随着负荷阶跃幅度的增大或调速不等率的下降而延长。与一次再热机组相比,二次再热机组一次调频控制系统动作较快,但调节过程中最大超调量较大。
Primary frequency regulation characteristics of double reheat unit have significant impacts on the operation stability and flexibility of power system due to its complicated flow process and large inertia. Based on the GSE simulation platform, the dynamic simulation models of the ultra-supercritical double reheat generation unit and primary frequency regulation were developed and validated by virtue of the combination of JTopmeret module and self-defined program. Then, the response characteristics of the thermal parameters in the double reheat unit during the primary frequency regulation process were studied. The effects of the load step amplitude and the speed droop on the primary frequency regulation characteristics were analyzed. It is discovered from the results that in the primary frequency regulation process of the double reheat unit, with step increase of the load power the real-time frequency will drop rapidly and DEH turbine control system will immediately take measures during dynamic processes, the real time frequency is less 50 Hz. Once the system reaches steady state, the relative change of flow volume and pressure of the primary and secondary reheat steam will be greater than those of the main steam. During the primary frequency regulation of the double reheat units, the increase of load step amplitude or the reduction of the speed droop, will both boost the dynamic overshoot of the frequency, and prolong the time duration for frequency regulation. Compared with single reheat generation units, the primary frequency control systems of double reheat units demonstrate faster response, whereas their maximum overshoot is larger during the regulation process.
作者
王珠
韩翔
许立环
赵永亮
种道彤
WANG Zhu;HAN Xiang;XU Lihuan;ZHAO Yongliang;CHONG Daotong(State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an Jiaotong University, Xi'an 710049, China;National Energy Group Suqian Power Generation Co., Ltd., Suqian 223800, China)
出处
《中国电力》
CSCD
北大核心
2019年第5期54-62,共9页
Electric Power
基金
国家重点研发计划资助项目(2017YFB0602101)~~
关键词
燃煤电厂
二次再热
一次调频
灵活性
调速不等率
动态特性
coal-fired power plant
double reheat
primary frequency regulation
operational flexibility
speed droop
dynamic characteristics
