Phenomenon, causes and treatment methods when the boiler is full of water
1、 Phenomenon:
1. The water level is not visible or not, and the high water level alarm;
2. When the steam temperature decreases, white steam can be seen in the main steam isolation valve of the boiler and the inlet valve of the steam engine;
3. Water impact of steam turbine or steam pipeline;
4. The feedwater flow is abnormally larger than the steam flow.
2、 Reason:
1. The water supply automatically jumps to manual, causing the abnormal increase of water supply;
2. The safety valve on the steam drum or steam header acts, causing the water level to rise or carry water;
3. The boiler evaporation capacity is overloaded, and the steam and water co-evaporation occurs.
2、 Reason:
1. The feed water automatically jumps to manual, resulting in abnormal increase of feed water;
2. The safety valve on the steam drum or steam header acts, causing the water level to rise or carry water;
3. The boiler's evaporation capacity is overloaded, and the steam and water co-boil.
3、 Treatment method:
When the boiler steam pressure and water supply pressure are normal, and the water level of the steam drum rises to more than+50mm, the following measures shall be taken:
1. Compare and flush the two water level gauges to check whether their indications are correct.
2. The water supply regulation is changed from automatic to manual. Close the manual water supply valve and turn down the main regulating valve to reduce the water supply.
If the water level in the steam drum is still rising after the above treatment and exceeds+75mm, the following measures shall be taken:
1. Open the emergency drain valve of the steam drum and close it immediately when the water level reaches the normal level.
2. According to the steam temperature, turn down or close the desuperheating water valve, open the main steam pipe drain valve and superheater drain valve.
After treatment, the water level of the steam package continues to rise. When the water level exceeds the visible water level at the upper part of the steam package water level gauge, the boiler shall be shut down in an emergency manner, the main pipe shall be disconnected as soon as possible, the water inlet shall be stopped immediately, the recirculation valve shall be opened, the boiler drainage shall be strengthened, the water level at the upper part of the steam package water level gauge shall be noticed, and the water level shall be closed after reaching the normal water level. After the standby furnace is normal, it can be operated according to the hot furnace heating.
If the water level cannot be seen in the steam drum water level gauge and is not found in time, the following measures shall be taken:
1. Compare and flush the two water level gauges to check whether the indication is correct. Open all the drain valves of the steam drum water level gauge, and then slowly close the drain valve. If there is water level in the water level gauge and the water level gauge continues to be filled, it is proved that the boiler water level does not exceed the steam side pipe of the water level gauge, it shall be treated as emergency boiler shutdown.
2. Open the drain valve of the water level gauge, and slowly close the drain valve. The water level is not visible in the water level gauge. To confirm that the water is seriously full, close the steam water valve, open the drain valve, discharge the water in the water level gauge, and immediately close the drain valve. Quickly and slightly open the steam valve water level gauge and fill it with water. At this time, it can be determined that the water level is higher than the steam side pipe of the steam water level gauge. It should be handled according to the emergency shutdown and be disconnected from the main pipe as soon as possible.
3. In case of boiler water level accident, if it is difficult to judge the water level, the boiler shall be shut down immediately. After the boiler is shut down, use the method of water filling to check the water level of the steam drum.