Abstract:In order to reveal the external characteristics and pressure pulsation characteristics of various critical operating points in the forward full-feature partition of the tubular pump device, taking a bulb tubular pump device with specific speed of 1179 as the research object, the forward full-feature test of the pump device involving the critical operating point was conducted. The external characteristic parameters and pressure fluctuations of a total of 64 flow operating points were collected in the experiment, and the external characteristics and pressure pulsation characteristics of various critical operating points in the forward full characteristic partition of bulb tubular pump device were emphatically analyzed. The test results showed that the turning-off point was the dividing point between the countercurrent braking condition and the pump condition. The head of the pump device near the turning-off point was 6.41m, which was 3.27 times of the head of the design point. The axial power was 15.39kW, which was 2.67 times of the design point power. The dimensionless peak value of pressure fluctuation at the inlet of the impeller was 1.26, the middle of the impeller was 0.99, the outlet of the impeller was 0.84, and the outlet of the guide vane was 0.23, which were 2.3, 2.8, 4.9 and 23 times of the design point, respectively. The zero head point was the boundary point between the pump condition and the positive current braking condition. The flow rate near the zero head point of the pump device was 1.42Qd, which was 1.42 times of the design point flow. The axial power was 2.41kW, which was 0.42 times of the design point power. The dimensionless pressure fluctuation peak value of the impeller inlet was 0.21, the middle part of the impeller was 0.21, the impeller outlet was 0.15, and the guide vane outlet was 0.01, which were 0.38, 0.6, 0.88 and 1 times of the design point, respectively. The zero torque point was the boundary point between the positive flow braking condition and the turbine condition. The flow at the near zero torque point of the pump device was 1.63Qd, which was 1.63 times of the flow at the design point, and the head was -1.36m, which was -0.69 times of the head at the design point. The peak value of pressure fluctuation at the inlet of the impeller was 0.37, the middle of the impeller was 031, the outlet of the impeller was 0.20, and the outlet of the guide vane was 0.04, which were 0.67, 0.89, 1.18 and 4 times of the design point.