Incident Handling 45: How should a circulating fluidized bed boiler be handled when it shuts down?

After the circulating fluidized bed boiler shuts down, the following measures should be taken immediately: (1) Stop all coal feeders immediately and switch all automatic controls to manual mode. (2) Start the oil guns above and below the bed to rapidly increase the bed temperature, thereby facilitating combustion. (3) Appropriately reduce the air volume according to the situation, adjust the amount of circulating ash, and discharge some ash if necessary. (4) Reduce the water supply volume, control the drum water level at -30 mm, and closely monitor the water level. (5) Based on the downward trend in steam temperature, reduce or shut off the desuperheating water, and activate the drain valve and vent steam to cool the superheater. (6) If there is a fault in the coal feeding system, it should be repaired as soon as possible; if the system is blocked, it should be cleared promptly. (7) If the bed temperature meets the conditions for hot start, a hot start should be carried out immediately; once the steam temperature and pressure reach the rated values, the turbine can be restarted. (8) If the bed temperature does not meet the conditions for hot start, purging must be performed followed by operation according to the cold start procedure. It is strictly prohibited to feed coal blindly, as this may lead to secondary combustion or furnace explosions, resulting in serious damage to the equipment. After the boiler shuts down, operators should promptly determine the cause; it is strictly prohibited to rely on luck or attempt to maintain the unit’s load by increasing the coal supply in order to raise the bed temperature. The above processing steps must be followed strictly to ensure the safe operation of the equipment.

After the circulating fluidized bed boiler shuts down, the following measures should be taken immediately: (1) Stop all coal feeders immediately and switch all automatic controls to manual mode. (2) Start the oil guns above and below the bed to rapidly increase the bed temperature, thereby facilitating combustion. (3) Appropriately reduce the air volume according to the situation, adjust the amount of circulating ash, and discharge some ash if necessary. (4) Reduce the water supply volume, control the drum water level at -30 mm, and closely monitor the water level. (5) Based on the downward trend in steam temperature, reduce or shut off the desuperheating water, and activate the drain valve and vent steam to cool the superheater. (6) If there is a fault in the coal feeding system, it should be repaired as soon as possible; if the system is blocked, it should be cleared promptly. (7) If the bed temperature meets the conditions for hot start, a hot start should be carried out immediately; once the steam temperature and pressure reach the rated values, the turbine can be restarted. (8) If the bed temperature does not meet the conditions for hot start, purging must be performed followed by operation according to the cold start procedure. It is strictly prohibited to feed coal blindly, as this may lead to secondary combustion or furnace explosions, resulting in serious damage to the equipment. After the boiler shuts down, operators should promptly determine the cause; it is strictly prohibited to rely on luck or attempt to maintain the unit’s load by increasing the coal supply in order to raise the bed temperature. The above processing steps must be followed strictly to ensure the safe operation of the equipment.