超超临界二次再热机组再热汽温调节方案应用分析

Analysis on the Application of Reheat Steam Temperature Control Strategy in Ultra Supercritical Units with Secondary Reheat Cycle

二次再热机组相对一次再热机组的热力系统具有更加复杂的结构,且国内二次再热技术的应用刚刚起步,缺乏建设与运行经验,从而导致新建二次再热机组难以确定调节方案。对国内新投产华能安源660MW、国电泰州1 000 MW超超临界二次再热机组再热汽温的调温原理、控制方案以及投运效果进行了详细的总结分析。分别给出了这2种典型调节方案的优势与缺陷,并基于此给出了改进建议,为二次再热机组再热汽温调节方案的选取与改进提供参考。

Compared with the single reheat units, the thermodynamic system of secondary reheat units is much more complicated. The application of the secondary reheat technology is just started in China with little construction and operation experience. Therefore, it is difficult to choose the regulating scheme for the newly-built secondary reheat unit. In this paper, the reheat steam temperature regulation principle, control strategy and operation results of the newly-built Anyuan 660-MW and Taizhou 1 000-MW secondary reheat units are analyzed in detail, in which the pro and cons of these two typical regulating schemes are presented. Based on the analysis, suggestions are proposed for the selection and improvement of the secondary reheat steam temperature regulating scheme.