Turbine depressurizes the high-pressure heater

After the boiler is disconnected from the grid, the feedwater temperature drops. With unchanged combustion conditions, more heat is required for evaporation; as a result, the steam production decreases, the flow rate of superheated steam falls, the heat absorbed per unit volume increases, and the temperature rises

So what should be done? Turn on the desuperheating water?

After the boiler is disconnected from the grid, the feedwater temperature drops. To maintain a constant load, the heat absorbed during evaporation increases, which leads to an increase in coal supply. As a result, the flow rate of flue gas passing through the heating surfaces of the superheater increases; in other words, the temperature of the superheated steam exhibits convective behavior (i.e., it rises as the coal supply increases). Consequently, the temperature of the superheater tube walls also increases. The solutions include increasing the flow rate of the cooling water; for coal-fired boilers, this involves switching the coal mills, activating the lower burners and shutting down the upper burners. For swing burners, the flame direction should be adjusted downward to reduce the height of the flame center. Additionally, enhanced soot blowing of the water wall inside the furnace is necessary. If these measures prove ineffective, the load on the unit should be reduced.