Optimal Design of Slit Impeller for Low Specific Speed Centrifugal Pump Based on Orthogonal Test

Abstract

Marine centrifugal pumps are mostly used on board ship, for transferring liquid from one point to another. Based on the combination of orthogonal testing and numerical simulation, this paper optimizes the structure of a drainage trough for a typical low-specific speed centrifugal pump, determines the priority of the various geometric factors of the drainage trough on the pump performance, and obtains the optimal impeller drainage trough scheme. The influence of drainage tank structure on the internal flow of a low-specific speed centrifugal pump is also analyzed. First, based on the experimental validation of the initial model, it is determined that the numerical simulation method used in this paper is highly accurate in predicting the performance of low-specific speed centrifugal pumps. Secondly, based on the three factors and four levels of the impeller drainage trough in the orthogonal test, the orthogonal test plan is determined and the orthogonal test results are analyzed. This work found that slit diameter and slit width have a large impact on the performance of low-specific speed centrifugal pumps, while long and short vane lap lengths have less impact. Finally, we compared the internal flow distribution between the initial model and the optimized model, and found that the slit structure could effectively reduce the pressure difference between the suction side and the pressure side of the blade. By weakening the large-scale vortex in the flow path and reducing the hydraulic losses, the drainage trough impellers obtained based on orthogonal tests can significantly improve the hydraulic efficiency of low-specific speed centrifugal pumps.

Effect of Splitter Blades on Performances of a Very Low Specific Speed Pump

“…The general performance and physical limitations of LSS pumps have been investigated by Kurokawa [6] and Olimstad [7]. Special design has also been proposed by Klas [8,9] where thick trailing edge replaced classic blading, or more recently by Wei [10] and Yang [11] who tested slit impeller blades on a pump with a specific speed n q = 5.7. Nonetheless, the most common solutions for LSS pumps is the addition of splitter blades to the impeller, to raise the pressure developed by the impeller as extensively studied in references [12][13][14][15][16][17], where generally variations of a splitter blade position in the impeller passage is studied for pump optimization.…”

Performance Optimization of Slotted Blades for Low-Specific Speed Centrifugal Pumps

“…Te blade method was originally used in the aviation feld, but it has not been well studied in centrifugal pumps. Currently, some scholars have studied the relationship between the shape of the slit vane and the performance of centrifugal pumps by using orthogonal tests, but they are not very comprehensive [19,20]. Zhang et al and Wei et al investigated the efect of slot width on drainage performance [21,22].…”

Optimization Design of Y-Shaped Settling Diversion Wall Based on Orthogonal Test

“…Shi et al [19] calculated the performance data of a gas-liquid mixed vane pump under each impeller size parameter scheme by using the orthogonal experimental design method of five factors and four levels. Yang et al [20] adopted the orthogonal test scheme of three factors and four levels to optimize the structural size design of the drainage channel of the low specific speed centrifugal pump. Zhou et al [17] used the orthogonal test scheme of four factors and four levels and the computational fluid dynamics method to analyze the flow characteristics of a diversion pier under different parameter combinations, obtaining the optimal value range of diversion pier size parameters of the lateral inlet pump station.…”