关键词: 火力发电机组, 供热改造, 设计, 控制, 保护, 热电联产

Abstract: In order to eliminate the potential safety problems which may endanger system operation of conventional thermal power units after heating system retrofit, by taking the heating system retrofit of a 600-MW unit of a power plant for example, the design characteristics such as the medium-pressure section exhaust steam and low-temperature reheat pipe extraction and the condenser water inlet system are presented. Through the analysis on the design principle of the thermal system and its heating operation mode, it is concluded that problems, such as over-current, over-voltage and overheating of blades, turbine overspeed and condenser water replenishment tend to arise after heating system retrofit. Therefore, the factors affecting the equipment safety are clarified. In addition, the effective control and protective measures are also put forward to avoid heating system accidents, ensure the safe operation of the unit, and achieve heat and power cogeneration.

Key words: thermal power generating unit, heating system retrofit, design, control, protection, heat and power cogeneration