Influence of impeller geometry on pump suction specific speed
Research on lowering the limitations of pump design in order for expansion of its applications as a major item of industrial equipment is of great importance. Due to the fact that design of pumps currently found in industry is limited by various factors such as suction specific speed, any modifications in the pump structure, leading to reduction of these limitations, results in wider range of application with higher efficiency, and hence, reduction of energy and other costs. Pumps are mostly widely used in oil industry; therefore, changes to fluid viscosity could affect specific suction speed and cavitation based on corresponding operating condition of the pump. There has been no prior research in literature investigating the effects of fluid viscosity alterations (due to fluid temperature rise, pumping conditions, climate changes, etc.) on pump suction specific speed, which establishes strong grounds for research and investigation of this matter.
In this work, a model of a centrifugal pump (32-160/2900 rpm manufactured by not important from Germany) was chosen with limited amount of information on the equipment, and its impeller and casing were modeled using CFTurbo software, with all sizes and dimensions determined as well as inlet and outlet angles. The purpose of this study was to reduce NPSHr via re-design of a currently available sample item, for which ANSYS CFX was used for computational simulation of the equipment. The output of simulation was cross-validated with manufacturer’s equipment catalogue until accomplishment of NPSHr optimization.
The results suggest that modifications to pump’s impeller inlet angle, NPSHr is decreased and pump suction specific speed and pump Efficiency being increased. Therefore, this approach would expand the boundaries of pump usage.
Thanks and let me have your opinion about that,
Salman Hamidi
+989365229981
Mechanical designer | Rotating equipment | FEA | CFD
6 年The procedure described for NPSH3 optimization doesnt make sense since the correlation between NPSHr and inlet angle is already known. The more the inlet angle, the less is the NPSHr. However, increasing the inlet angle beyond shockless entry will increase NPSHi and decrease impeller life cycle. In addition, simple cfd simulation as far as i can see in the fig is not able to NPSHr accurately, complex multiphase analysis is needed in this case. Best regards.