火力发电厂纯凝机组供热改造中控制系统设计分析

Controlsystem design analysis of coal-fired power plant in heating transformation of condensing power unit

火电厂中小型纯凝机组存在效率低、煤耗高、污染大等问题,经济效益不很理想,而中小热电联产机组关闭后形成的供热负荷缺口又亟需填补。为适应形势变化,近几年大量的纯凝机组陆续转型为抽凝式热电联产机组。以某电厂容量为2×225 MW+2×300 MW的机组为例,针对亚临界纯凝机组供热改造中存在的问题,选取控制系统和控制逻辑的设计进行分析,并给出针对性建议。

In coal-fired power plants,the economic benefits of medium and small sized condensing power units are not as ideal as expected due to existing problems,such as low efficiency,high coal consumption and large-scale pollution etc. In addition to the shutdown of medium and small sized cogeneration units,the formed heating gap is in urgent needsto be filled. Therefore,a large number of condensing power units has been transformed to extraction condensing cogeneration units gradually in recent years in order to meet the changing situation. Taking the 2 × 225 MW + 2 × 300 MW units of a certain power plant as an example and aiming at the problems that exist in the heating transformation of subcritical condensing power units,this paper analyzed the design of control system and control logic and provided corresponding recommendations.