Guide: Phenomenon: Invisible or no water level, high water level alarm; steam temperature decreases, white steam can be seen in the main steam isolation valve and steam turbine inlet valve of the boiler; water shock occurs in the steam turbine or steam pipeline; abnormal feedwater flow is greater than steam flow.
phenomenon：
(1) If the water level is not visible or absent, the high water level alarms;
(2) As the steam temperature drops, white steam can be seen in the boiler main steam isolation valve and steam turbine inlet valve;
(3) Water shock in the steam turbine or steam pipe;
(4) The feedwater flow is abnormally larger than the steam flow.
The reason：
(1) The water supply automatically jumps to manual, causing abnormal increase in water supply;
(2) The safety valve on the steam drum or steam header operates, causing the water level to rise or carry water;
(3) The boiler's evaporative capacity is overloaded, and a co-leakage of steam and water has occurred.
Deal with：
1. When the boiler steam pressure and feed water pressure are normal, but the drum water level rises above +50mm, the following measures should be taken:
(1) Compare and flush the two water level gauges of the steam drum to check whether the instructions are correct.
(2) The water supply adjustment is changed from automatic to manual, close the manual water supply door and close the main adjustment door to reduce the water supply.
2. If the water level in the steam drum still rises after the above treatment, and exceeds +75mm, the following measures should be taken:
(1) Open the steam drum emergency drain door and close it immediately when the water level reaches the normal level.
(2) According to the steam temperature, close or close the desuperheating water door, open the main steam pipe trap and superheater trap.
After treatment, when the water level of the steam drum continues to rise, and exceeds the visible water level on the upper part of the steam drum water level gauge, stop the boiler urgently, disconnect from the main pipe as soon as possible, immediately stop the water intake, open the recirculation door, strengthen the boiler water discharge, and pay attention to the steam drum When the water level appears on the upper part of the water level gauge, it will be closed after the water level reaches the normal level. After the standby furnace is in normal condition, obtain the approval of the supervisor, and operate as the hot furnace.
3. If the water level is not visible in the steam drum water level gauge, the following measures should be taken:
(1) Compare and flush the two water level gauges of the steam drum to check whether the instructions are correct. Fully open the steam drum water level gauge discharge door, and then slowly close its discharge door. If there is a water level in the water level gauge and continue to rise to fill the water level gauge, it proves that the boiler's full water has not exceeded the steam side pipe of the water level gauge.
(2) After opening the water level meter discharge door and slowly closing the water level meter, the water level cannot be seen in the water level meter. In order to verify that it is seriously full of water, close the soda valve again and open the drain door. After the water in the water level gauge is exhausted, the drain door should be closed immediately. Open the steam valve quickly and the water level in the water level gauge appears and is full of water. At this time, it can be determined that the water level has exceeded the steam side pipe of the steam drum water level gauge. It should be handled as emergency shutdown and disconnected from the main pipe as soon as possible.
(3) When a boiler water level accident occurs, if it is difficult to determine the water level, the boiler should be shut down immediately. After stopping the boiler, use the water bidding method to bid water and check the water level of the steam drum.
