The pressure gauge of the boiler is an indicator reflecting the internal pressure of the boiler.Once the boiler pressure gauge is found abnormal, how to deal with this abnormal situation?To deal with abnormal, we should first analyze the reason of abnormal pressure gauge in combination with other situations, and then take corresponding measures.Generally speaking, the pressure gauge is abnormal for the following reasons:
1, boiler overpressure
(1) the sharp rise in air pressure exceeds the permitted working pressure, the pointer of the pressure gauge exceeds the permitted working "red line", after the safety valve operation, the pressure is still rising.
(2) send out overpressure alarm signal, overpressure interlock protection device action.
(3) the steam temperature increases and the steam flow decreases.
(1) quickly weaken the combustion, manually open the safety valve or vent valve.
(2) increase the water supply, at the same time in the next drum to strengthen sewage (at this time should pay attention to maintain the normal water level of the boiler) to reduce the temperature of the pot water, so as to reduce the pressure of the boiler drum.
(3) If the safety valve is out of order or all the pressure gauges are damaged, the furnace should be stopped in an emergency, and the pressure can be increased until the safety valve and pressure gauges are repaired.
(4) When the overpressure of the boiler endangers the safe operation, step-down measures should be taken, but it is strictly prohibited to step-down too fast.
2, boiler tube burst
(1) the sound of soda spray can be heard when the tube bursts, and there is an obvious popping sound when it is serious.
(2) the furnace from negative pressure combustion into positive pressure combustion, and furnace smoke and steam from the furnace wall door hole and a large number of air leakage ejected.
(3) the feed water flow is not normal, greater than the steam flow.
(4) Although the water supply is increased, the water level is often difficult to maintain, and the steam pressure is reduced.
(5) the exhaust temperature decreases and the color of the smoke becomes white.
(6) furnace temperature reduction, and even fire extinguishing.
(7) The load of induced draft fan increases and the current increases.
(8) water flows out of the bottom of the boiler and ash increases.
(1) The furnace tube burst leakage is not serious and can maintain the water level. When the accident does not expand, the load can be reduced for a short time to maintain the operation, and the furnace can be stopped after the standby furnace is started.
(2) when the furnace tube is broken and the water level cannot be maintained, the furnace should be stopped urgently, but the induced draft fan should not be stopped. It should also continue to supply water to the boiler and reduce the temperature of the pipe wall, so that the accident will not be expanded again.
(3) if the boiler is short of water and the tube wall is overheated and the tube is exploded, the boiler should be stopped urgently, and it is strictly prohibited to feed water to the boiler. At this time, the fire in the furnace should be removed as soon as possible, the temperature in the furnace should be reduced, and the degree of overheating of the boiler should be reduced.
(4) if there are several boilers parallel steam supply, the main steam pipe of the accident boiler should be cut off from the steam master pipe.
3. Superheater tube blasting
(1) there is a sound or explosion of steam near the superheater.
(2) the steam flow rate is abnormally decreased and the flow rate is abnormally smaller than the feed water flow rate.
(3) the negative pressure in the furnace is reduced or changed to positive pressure. When it is serious, steam and smoke are sprayed out of the furnace door and fire hole.
(4) the flue gas temperature after the superheater decreases abnormally or the temperature difference between the flue gas before and after the superheater increases.
(5) when the damage is serious, the boiler steam pressure drops.
(6) The exhaust temperature drops significantly, and the color of the exhaust smoke from the chimney becomes gray or white.
(7) The load of induced draft fan increases and the current increases.
(1) The superheater tube is slightly broken, and the load can be appropriately reduced to maintain operation in a short period of time. At the same time, the leakage situation should be closely monitored and the standby boiler should be started quickly.If the fault condition worsens during monitoring, the furnace should be stopped as soon as possible.
(2) when the superheater tube bursts seriously, emergency stop must be made.
4. Boiler water hammer
(1) in the boiler and pipeline has a certain rhythm of the crash sound, sometimes loud, accompanied by strong vibration of water supply pipeline or steam pipeline.
(2) the pointer of the pressure gauge swings back and forth, consistent with the sound frequency of vibration.
(3) When the water hammer is serious, it may lead to the connecting parts, such as welding crack and valve damage.
Treatment of water hammer in drum:
(1) such as check valve failure, should weaken the combustion, reduce the load and pressure, close the feed water stop valve, stop the feed water, quickly repair the feed water check valve.At the same time, the water level should be observed to prevent water shortage accidents.
(2) for the boiler drum fire when the steam heating device, should quickly close the steam valve.
(3) keep the water level running in the boiler, and feed water into the drum evenly and evenly.Such as water hammer is still continuous, should stop furnace maintenance.
(4) boiler maintenance, should strengthen the repair of water supply pipe, water distribution pipe and water tank.
Treatment of steam pipe water hammer:
(1) reduce the steam supply, if necessary, close the main steam valve.
(2) Open the trap on the superheater collector and steam pipe to drain water.
(3) the water level of the drum is too high, it should be properly drained to maintain the normal water level.
(4) strengthen the water treatment work, ensure the quality of water supply and pot water, to avoid the occurrence of soda total teng.
(5) after the elimination of the water hammer, check the pipe and pipe rack, flange and other places, if there is no situation to warm the pipe once for steam supply.
Treatment of economizer water hammer:
(1) open the discharge valve on the economizer outlet collection box to exhaust the clean air.
(2) check the check valve on the economizer inlet, and repair or replace it in time if any damage is found.
(3) continuously feed water to the boiler, and strictly control the outlet water temperature of the economizer, which should generally be lower than the saturation temperature of 40℃.If the temperature is found to be too high, vaporization may occur, the recirculation pipe should be opened, or the bypass flue should be opened, or the return pipe valve should be opened to return the economizer water to the tank.