The self-checking method is a method for the daily inspection of the fire pump in the fire water supply system. In the self-checking of the fire pump, it can not only prevent the rust and jam of the fire pump, but also alarm when the motor overload, short circuit, overvoltage, phase loss, undervoltage, overheating, etc. The self-inspection of the fire pump is a kind of technological progress to improve the management level of the system.
In the two fire pump self-inspection methods, both can reflect the self-inspection on the maintenance of the fire pump, but the low-speed self-inspection method only runs a preliminary stage in the start of the fire pump, and cannot fully reflect the actual operation working conditions of the fire pump in the future. In addition, after the results of the self-check of the fire pump are fed back to the fire control center, further judgments need to be made manually. Therefore, the fire pump self-checking method cannot completely replace the manual maintenance and management of the fire pump.
2. Analysis of self-checking method
The constant-speed self-check mode simulates the actual working conditions of the fire water supply within a certain period of time. What it detects is the whole process of starting and normal operation of the fire pump. The pipeline design needs to be improved. It is important to prevent the solenoid valve on the bypass pipeline from malfunctioning. It must be opened during the self-check, and closed in time after the self-check is completed.
The low-speed self-check method does not need to modify the pipeline of the fire pump, but it only detects a stage in the normal working condition of the fire pump. Fire pumps can be divided into direct start and indirect start. The more powerful ones need indirect start. The indirect start has Y/△ step-down start, auto-coupling step-down start, soft starter start, etc. In the operation of the fire pump, the start of the soft starter is only an early stage of the operation of the fire pump, and then it is normal operation. The frequency conversion method also failed to run to the power frequency stage. However, the low-speed self-check method still has a certain effect on preventing the corrosion of the fire pump. Relatively speaking, it has the characteristics of low-frequency drive, low-speed rotation, and low-power operation of the equipment.
3. Comparison of self-checking methods
In the fire pump self-inspection methods, both the normal-speed self-inspection method and the low-speed self-inspection method play a certain role in the maintenance of the fire pump. From the perspective of maintenance and management, they can all be used in the fire water supply system. Relatively speaking, the normal speed self-check method can reflect the actual operating conditions of the fire pump. From the perspective of the cause of the fire pump failures, the failures caused by the long-term use of the fire pump is mainly the seizure of the pump set shaft. There are fewer problems with incomplete motor starting conditions, so it is not very meaningful to overemphasize the operation of the fire pump under complete conditions. The normal-speed self-check method is suitable for the situation where the fire pump suctions water from the fire tank, and the layout of the pipeline should be considered reasonably in the design. There are certain problems in operation, which can quickly cause overpressure, which is not very suitable for application in engineering. The normal-speed self-check mode and the low-speed self-check mode have their own characteristics. Although the low-speed self-inspection method is not comprehensive for the operating conditions of the fire pump, it has no special requirements for the design of the fire pump pipeline, and it can basically be applied to the technical requirements of the fire pump self-inspection. It is more suitable for the situation where the fire pump sutions water directly from the municipal pipe network.