Influence of Channel-Diffuser Blades on Energy Performance of a Three-Stage Centrifugal Pump

Abstract

In order to improve hydraulic efficiency, influence of inlet angle, outlet angle, wrap angle, inlet shape and outer edge camber lines of channel-diffuser blades on the energy performance of a three-stage centrifugal pump were studied and the pressure distributions on the blade of the first-stage channel-diffuser were particularly analyzed. The result shows that the efficiency of the pump is maximal when the blade inlet angle is 12°. The pressure variation in the model with the inlet angle of 12° was small and the amplitude of fluctuation was also not large. When the outlet angle was 90°, the pressure distribution in the outlet of the blades that are symmetrically distributed along the center of the diffuser shell was significantly better than that with other outlet angles. The effect of the blade wrap angle of the channel-diffuser on the energy performance of the pump was relatively small. The internal flow in the diffuser with the diffusion inlet shapes was steady for both the convex surface and concave surface. The diffusion inlet of the channel-diffuser blade corresponded to the outlet region of the impeller blade, which reflected a good matching. The fluctuation amplitude and the distribution range of the models with a uniform transition were smaller than those with non-uniform transition. In order to verify the effectiveness of the research results, an experimental test was carried out on the pump. The results show that when the flow rate is 850 m3/h, the head of the pump is 138.67 m and the efficiency of pump is 69.48%.

Computer Flow Simulation and Verification for Turbine Blade Channel Formed by the C-90-22 A Profile

“…The working medium expands in the narrowing channels formed by blades (Figure 1); that is, potential energy is converted into kinetic energy, which, in turn, is converted into mechanical energy of shaft rotation in the working arrays. The working medium flow in the channels of bladed machines is invariably accompanied by aerodynamic energy losses, which directly depend on the bladed channel shape [12,13]. They can be conventionally divided into two groups:…”

Effects of oscillation frequency on the flow characteristics of a centrifugal pump impeller with sinusoidal flow rate

“…Braun et al 10,11 investigated a double-suction centrifugal pump through simulation and experiment, and stall units are observed in the diffuser, where their amplitude is two times larger than that in the nonstall state. Other researchers analyzed the stability of centrifugal pump from the perspective of energy change [12][13][14][15][16][17][18] and vortex development. [19][20][21][22][23][24][25][26] These studies give researchers a clear understanding of the internal flow characteristics of centrifugal pumps under quasi-steady conditions.…”