Improved Boiler-Turbine Coordinated Control of CHP Units with Heat Accumulators by Introducing Heat Source Regulation

Energies

Yang Sun¹  Sitong Jing¹  Can Cui²  Wei Wang³  Wenguang Zhang³ 

[1] School of Control and Computer Engineering, North China Electric Power University, Beijing 102206, China;School of Humanities and Social Sciences, North China Electric Power University, Beijing 102206, China;State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, Beijing 102206, China;

关键词: combined heat and power (CHP);    heat accumulator;    load change;    coordinated control;    ramp rate;   

DOI  :  10.3390/en11102815

来源: DOAJ

【 摘 要 】

It is significant for power system stability to improve the operation flexibility of grid-connected units. Such improvement has always been a hot topic, especially for coal-fired units. In recent decades, it has become increasingly urgent and challenging as large-scale fluctuant renewable energy is connected to the power grid. Boiler-turbine coordinated control strategy (CCS), which is employed to perform unit load control according to automatic generation control (AGC), has a slow ramp rate in general on account of large delay and inertia of boiler, so to improve the unit operating flexibility, it is necessary to explore usable heat storage and optimize the control strategy. In combined heat and power (CHP) units with heat accumulators, their heat and power are decoupled. Therefore the extraction steam that goes to the heating station can be regulated flexibly even operating in “heat-led mode”. The change of extraction steam flow has a significant influence on the turbine power output, so we propose to improve the load-following capability of CHP units by regulating the heat source flow. In this paper, the influencing model is set up, and it is about heat source flow variations on the electric power output. The load control strategy is further optimized and designed through combinations of CCS and heat source regulation. Finally simulations and analysis are performed on a 330MW CHP unit, and the results reveal that the power ramp rate with our strategy is two times faster than that with traditional strategy.

【 授权许可】

Unknown