There are many reasons for the vibration of the unit and the pump room building. In summary, there are mainly the following four reasons.
1: Electrical
The motor is the main equipment of the unit. The internal magnetic imbalance of the motor and the imbalance of other electrical systems often cause vibration and noise. For example, in the operation of an asynchronous motor, the radial alternating magnetic pull between the stator and the rotor generated by the interaction of the stator and rotor tooth harmonic magnetic flux, or the large synchronous motor in operation, the stator and rotor magnetic center is inconsistent or the air gap difference in all directions Exceeding the allowable deviation value, etc., may cause the motor to periodically vibrate and make noise.
2: Mechanical
Motor and water pump rotating parts are unbalanced in quality, shoddy, poor installation quality, asymmetrical axis of the unit, swing exceeding the allowable value, mechanical strength and rigidity of parts are poor, bearing and sealing parts wear and damage, and the critical speed of the water pump appears to be related to the unit The resonance caused by the natural frequency all the time will cause strong vibration and noise.
3: Hydraulic
Uneven flow rate and pressure distribution at the inlet and outlet of the pump, pressure pulsation of the working fluid at the inlet and outlet of the pump, liquid bypass, deviation and de-flow, non-rated working conditions and pump cavitation caused by various reasons are common causes of pump unit vibration s reason. The dynamic transition processes such as pump startup and shutdown, valve opening and closing, changes in working conditions, and emergency shutdown in accidents caused rapid changes in pressure in the water pipeline and water hammer, which often caused vibrations in the pump room and unit.
4: Others
Improper design of the inlet flow path of the unit or unmatched design with the unit, improper submerged depth of the pump, and unreasonable sequence of starting and stopping the unit, etc., will deteriorate the water inlet conditions, produce vortexes, induce cavitation or aggravate the vibration of the unit and pump room. When the unit with the vacuum cut-off breaks the siphon is started, if the air entrainment in the hump section is difficult, the siphon time is too long; the design of the shutter door of the shut-off unit is unreasonable, and it is constantly opened and closed, constantly hitting the door seat; support Uneven settlement of the foundation of the pump and motor or poor rigidity of the foundation will also cause the unit to vibrate.
