Analysis and elimination of common failures of circulating feed water pump for boiler
The circulating feed water pump for the boiler is the key to the safe and stable operation of the boiler system. It is an important part of the boiler automatic liquid level adjustment system designed and constructed using modern automatic control technology. The foundation of the boiler operation when the feed water pump is operating stably is an important part of the modern boiler liquid level adjustment system. Once the feedwater pump fails, it will seriously endanger the safety of the boiler's operation, and severely will also lead to major accidents. Therefore, strengthening the daily maintenance and repair of the boiler system feed pump has become an important task for modern boiler maintenance departments.
Analysis and elimination of common failures of circulating feed water pump for boiler
1. Cause analysis of the failure of the circulating feed water pump for the boiler
The feedwater pump system of modern large boilers is composed of multiple feedwater pumps, mainly composed of two to three start-up feedwater pumps, and one or two electric feedwater pumps are used as backup or auxiliary. This kind of feedwater pump configuration is beneficial to start the standby feedwater pump system to supplement the insufficient supply when the main feedwater pump system fails or cannot meet the boiler operation requirements, and avoids the shutdown of the boiler due to the feedwater pump failure.
Common boiler feedwater pump failures are mainly concentrated in the lubricating oil system, wind shelter system, speed control system, auxiliary motor overheating and insufficient flow. Through scientific analysis and finding the cause of the fault, it is the basis for troubleshooting and solving the boiler feed water pump fault. Only by eliminating the cause of the fault can the same type of fault appear again.
2. Failure analysis and elimination of circulating feed water pump for boiler
The common faults of the circulating feed water pump for the boiler are: (1) The electric feed pump motor is overheated. (2) The feed water pump body is overheated. (3) The boiler feed water pump has insufficient flow.
Analysis and elimination of motor overheating of circulating feed water pump for electric boiler: For feed water pump powered by electric motor, motor overheating is the most common. The main reason for the overheating of the motor is the overheating of the motor due to high or low voltage, poor transmission, failure of the ventilation system or unit failure. When the motor is overheated severely, it will cause insulation burnout and rotor breakage. Therefore, when it is found that the motor is overheated, other pneumatic power methods should be used to shut down for maintenance. Motor overheating caused by voltage should check the motor power supply system, and solve the boiler feedwater pump motor overheating fault by restoring stable power supply.
In addition, poor transmission can also cause the motor to overheat. Due to the poor transmission between the motor and the feed water pump, the motor load is too large, and the phenomenon of small horse-drawn carts appears. Motor overload is the temperature increase. This situation must be overhauled in time, causing the unit to malfunction. Thorough investigation of the traditional system of electric motors and feedwater pumps. Common traditional problems are mainly caused by lack of oil in the rotating bearings of the transmission system and bearing damage. Find out where the fault is and replace or lubricate.
One of the most common faults when the motor is overheated due to the failure of the same sub-system. It is mainly due to the damage of the fan, the blockage of the ventilation ducts, the wear of the bearing, etc., which make the ventilation system unable to complete the work it should undertake, causing the motor to overheat and burn out in serious cases Coil. This situation must be investigated item by item to find out the cause of the failure. The failure can be solved by clearing the ventilation channels, repairing the fan, and replacing the bearing.
Boiler circulating feed water pump pump body is overheated: The common cause of boiler feed water pump pump body overheating is caused by friction caused by damage to the bearing, or caused by lack of oil in the lubrication system and poor oil quality. Therefore, after finding that the feedwater pump body is overheated, first check whether the lubrication system is lack of oil or the lubricating oil contains impurities, and secondly, check whether the bearing is damaged. For the overheating of the pump body that has just been overhauled, check whether the gap between the rolling bearing or the bracket cover is too small.
After the above inspection, the pump body still shows heat. Check whether the pump shaft is bent or the two shafts are not concentric. At the same time, check the balance of the impeller, adjust the pump shaft or adjust the concentricity of the two shafts, and clear the balance hole of the impeller to ensure the rotation of the pump shaft and the impeller. Balance and troubleshoot.
Insufficient flow of circulating feed water pump for boiler: The main reason for the flow of boiler feed water pump is mainly caused by damaged pump blades, blockage of pipelines or leakage. For feedwater pumps with belt drive, consider whether the low speed caused by belt slippage causes insufficient flow. After checking the belt, check the pipeline. If the flow is still insufficient at the blockage and leak, consider whether the impeller is damaged. Check the impeller and lubricate the bearing and other parts to avoid insufficient flow due to insufficient speed due to poor lubrication or damage of the bearing.
Elimination of vibration faults of the circulating feed water pump system for boilers: The fault of the bearing system of the boiler feed water pump will cause insufficient flow, heating of the pump body, and poor operation. One of the reasons for the failure is due to lack of lubrication or impurities in the lubricating oil On the one hand, the vibration of the unit will also cause an increase in the failure of the bearing system. Excessive vibration of the feedwater pump system has an important impact on the safety of the entire unit, seriously jeopardizing the safe and stable operation of the unit, and excessive vibration has an important impact on the unit and its foundation. The cause of excessive vibration of the unit is mainly due to the deformation of the pump shaft or the rotor shaft of the motor, the damage of the bearing and the loosening of the fixing bolts of the base. After excessive vibration of the unit occurs, first check whether the fixing base bolts are firm, and secondly check whether the bearing parts are overheated and not rotating smoothly. If the line is over the above conditions, it can be determined that the excessive vibration is caused by the damage of the bearing. If the vibration of the unit remains unchanged after other reasons are eliminated, it can be considered that the vibration is excessive due to the deformation of the pump shaft or the motor rotor shaft. The deformation of the pump shaft or the rotor shaft of the motor is mostly temporary deformation, which is caused by partial overheating caused by damage to the bearing of the unit. The temperature equilibrium deformation can disappear after the shutdown.
