Abstract: A certain type of air-conditioning drainage pump has a problem of beat vibration under certain working conditions. First, a two-phase flow transient simulation is used to confirm that the source of beat vibration is the pressure pulsation in the static and dynamic gap between the pump casing and the impeller. Monitoring the pressure pulsation at 14 monitoring points in the pump housing at a flow rate of 300 mL/min, 500 mL/min (pump design working point), and 700 mL/min, it is clear that there is a maximum pressure pulsation amplitude only at a flow rate of 500 mL/min. Based on this, the impeller optimization plan is proposed. The impeller wheel cover is opened near the outlet side, and the flow pattern in the pump is changed without changing the flow rate of the entire pump, and the pressure pulsation frequency of the dynamic and static gaps is changed to achieve vibration improvement. Provide a solution for the vibration problem of this kind of self-priming pump working under low flow rate.

Key words: Self-priming pump, Beat vibration, Gas-liquid two-phase flow, Pressure pulsation