Analyses on combustion characteristics and the region of corrosion failure risk of high-temperature heating-surface in peak-loading power plant boiler

Deep peaking will be the operating norm for thermal power units to address the intermittent supply of clean energy. However, the heat exchanger serves the temperature fluctuation conditions in the boiler during deep peaking. It will result in a risk of corrosion failure of high-temperature heating surfaces such as superheater and reheater. The paper investigated the combustion characteristics of coal-fired boilers at 100% and 50% loads. The temperature and velocity field distributions under different loads are clarified. The corrosion failure risk area of the furnace heating surface in the boiler was also analyzed based on the flue gas temperature distribution in the boiler furnace at 100% and 50% loads. The results show that the 10th platen of the rear platen superheater is at the highest service temperature and in the region with more significant temperature fluctuations, which is susceptible to corrosion failure. The paper provides a theoretical reference for the safe operation and periodic maintenance of deep-peaking units.