Research on the Matching Characteristics of the Impellers and Guide Vanes of Seawater Desalination Pumps with High Capacity and Pressure

This paper presents the matching characteristics of impellers and guide vanes of high capacity and pressure seawater desalination pumps by using computational fluid dynamics (CFD). The single-stage pump is numerically calculated, and its external characteristics are consistent with the test results of model pump. Taking this scheme as a prototype, the research is carried out from three aspects: (i) the impeller blade outlet width; (ii) the number of impeller and guide vane blades; and (iii) the area ratio of impeller outlet to guide vane inlet. The results indicate that the blade outlet width significantly affects the pump head and efficiency. Appropriately increasing the number of guide vane blades or changing the number of impeller blades can improve efficiency and expand the high-efficiency area. Additionally, increasing the throat area of the guide vane has the opposite effect on the large flow and small flow area of the pump. An optimized hydraulic model design scheme is obtained.

Research on acoustic behaviors of water pipelines with guide vanes

In this paper, the pipeline with guide vanes was taken as the research object, the flow noise was studied based on the hybrid calculation method, then the acoustic-structure coupling method was introduced to study the vibration and radiation noise, and then explored the best position of the guide vanes. Based on the pipeline experimental platform and improved experimental methods, it was found that the guide vanes had a better noise reduction effect on the elbows; based on that, a simulation study was carried out on the elbow with guide vanes, and the mechanism of the guide vanes on the velocity field and pulsating pressure of the pipeline was explored. Finally, the noise reduction effect at different positions of the guide vanes under different flow speeds was studied. The results indicated that the guide vane at the middle of the elbow had the best effect on improving the flow field and reducing noise in the working conditions studied in this article, providing a calculation basis for the design of the guide vane.

Methodology for comparing the energy efficiency of methods for regulating the performance of a blower station

A methodology for comparing the energy efficiency of different methods of regulating the total productivity of a blower station is presented. The basic principles of electrical modeling of duct networks are shown for the mathematical description of their properties and characteristics. The results of a comparison of the energy efficiency of regulating methods for a single fan and a group of five fans operating on a common line are presented. The conclusion about the high energy efficiency of the combination of start-stop control with smooth control using axial guide vanes for a blowing station of five fans is obtained.

Analysis of the Influence of Inlet Guide Vanes on the Performance of Shaft Tubular Pumps

To study the influence of inlet guide vanes (IGVs) on the pressure pulsation of a shaft tubular pump, this paper first conducts an experiment to study IGVs. Then, numerical calculations of the shaft tubular pump with and without IGVs are performed to analyze the hydraulic performance and pressure fluctuation characteristics. Finally, the reliability and accuracy of the data are verified by a model test. Numerical simulation results show that with additional IGVs, the pressure pulsation amplitude at the impeller inlet first decreases and then increases under small-flow and design conditions but gradually increases under large-flow conditions. When the IGVs are added to the impeller inlet of the shaft tubular pump, the hydraulic loss in front of the impeller inlet increases, resulting in a significant drop in the head and efficiency of the pump device when the flow rate is less than 1.12 Qd; when the flow rate is greater than 1.12Qd, the head and efficiency of the pump device do not change significantly. IGVs can improve the condition of impeller water inflow and reduce pressure fluctuation on the blade surface.