Atmospheric hot water boilers have openings on the top. Therefore, during operation or when the pump is stopped, water in the system higher than the boiler can easily overflow from the openings in the boiler, which is called "run water".
There are three situations in which it runs:
First, the boiler runs after the pump is stopped.
The second is the boiler running water during operation.
Third, the boiler ran out of water after a sudden power outage.
停泵后锅炉跑水 1: The boiler runs after the pump is stopped
When the boiler is running, the system is full of water. When the amount of water sent by the pump is equal to the amount of water returned by the system, it will not run.
When the pump is stopped suddenly, the pump stops sending water. At this time, the water that is higher than the boiler system will overcome the resistance of the return water system, all flow into the boiler, and run out of the boiler expansion tank. This running water is called stopping the pump running water.
Since the outlet of the circulating pump is equipped with a check valve, it is impossible for the system water to flow back to the boiler from the water supply pipe under its "check" function. Therefore, the solution to stopping the pump and running water is to check the check valve and close it immediately when the pump is stopped. The return water valve makes it too late to run out.
2: running boiler water during operation
During the operation of the boiler, the water level of the high-level water tank gradually rises, and then flows out of the overflow pipe. At the same time, the water level of the boiler gradually decreases until the water level is not visible on the water level meter. This kind of running water is likely to cause water shortage in the boiler.
The cause of this phenomenon is that the opening height of the water outlet valve is too small or the circulation pump fails, which causes the circulation flow to decrease, the pressure of the entire system increases, and the high-level water tank will leak out, while the boiler water level drops, and the water tank runs. serious.
The solution for the boiler running water during operation is to immediately stop the boiler and check the opening degree of each water outlet valve, and check whether the circulation pump has air resistance, and check whether the return water valve is open and the valve core is not open.three: Boiler runs after sudden power outage
Due to the failure of various systems after a sudden power failure, the heat of the unburned coal in the furnace continues to be exerted, and the hot water in the boiler furnace cannot be replenished with cold water due to the stop of the circulating pump, causing the boiler temperature to rise sharply, resulting in vaporization. The phenomenon that the water is ejected from the opening of the expansion tank by the steam to cause the boiler to overflow is commonly referred to as "opening the boiler."
The solution to the boiler running water caused by the sudden power failure is to reduce the temperature of the boiler. Therefore, open all the furnace doors, cool them down by natural ventilation, and pull out the unburned coal in the furnace from the furnace door.
At the same time, the tap water pipe is used to fill the boiler with cold water, and the sewage valve is opened for drainage. For this emergency operation, the staff of the boiler should be responsible, not leave the job, pay attention to temperature changes at any time, and keep the normal water level of the boiler not lower than Low water mark.
Direct-supply heating systems also have the possibility of tube burst accidents. The reason is that the newly built boiler and heating network did not flush the system according to regulations before commissioning, and the debris accumulated in the boiler after commissioning caused blockage; the operating boiler and heating network were not properly maintained during shutdown and caused a lot of corrosion products. Or the dirt of the user's heating system, improper use or cleaning of the hot net decontamination device will cause the dirt to accumulate in the pipe and cause blockage.
Therefore, at the time of completion, the boiler and heating network must be carefully cleaned, boiler maintenance should be strengthened to reduce the deposition of corrosion products, and the boiler and heating network should be cleaned before heating each year to improve the quality of the circulating water; the decontamination device should be cleaned frequently during operation to block the heat in the heating network. Impurities enter the boiler.