Experimental study of energy-saving realized with the improvement of inner roughness in double-entry centrifugal pump

In this study, we test the effects of the surface roughness on the hydro efficiency of double-suction centrifugal pumps (Q = 70.7m3/min, H = 87 m). The original surface of the impeller and inner casing were coated, resulting in surface-roughness reductions ranging from 100-110 μm to 0-0.08 μm. We conducted experimental studies to measure the efficiency of the pumps and operating-pump electro energy variations with different surface roughness values. The experimental results showed that the efficiency of the pumps increased by about 0.81.79% and the electric energy of the operating pump was reduced by around 4.38 ; 6.08%. These results indicate that the performance of the pumps depend largely on the surface roughness of the impeller and inner casing, and by reducing the surface roughness, we can improve the efficiency of the pump and reduce costs by reducing the electric energy consumption.