Experimental Research on the External Characteristics of the Full-flow Pump in Longkungou North Rainwater Drainage Pumping Station

The full-flow pump is a new mechatronics product combining tubular pump technology and submersible motor technology and the purpose of this paper is to test the hydraulic performance of the full-flow pump device and understand the real operation status of the pump‐ing station.To study the external characteristics of the full-flow pump device with model test,this paper takes Longkungou North rainwater drainage pumping station as an example and then analyzes and evaluates relevant data.When the blade angle is fixed at+2 degrees,the max‐imum efficiency of the prototype device is 65.25%,when the flow rate is 15.35 m~3/s and the head is 2.16 m.Within the range of test head,the NPSH of Longkungou North rainwater drainage pumping station is sufficient,which will not cause cavitation hazards.The runaway speed corresponding to the maximum head is 216 r/min,which is 1.49 times of the rated speed.Under the condition of original design head,the op‐eration efficiency of the pump device is low,which does not meet the designed efficiency requirements of the pump station and it’s verified that the energy characteristics,cavitation characteristics and runaway speed characteristics corresponding to the design head of the pump de‐vice can meet the requirements after the clearance is adjusted between the impeller shell and the impeller outer ring and reducing the preci‐sion error of model test.The size of full-flow pump is relatively small and it has a compact structure and excellent hydraulic performance,which has a good prospect and can be adopted in low head and large flow pump stations.