Effect of blade number matching of impeller and diffuser in high-speed rescue pump

Abstract

In order to meet the requirement of coal mine flooding emergency rescue, a high-power, high-head, and small-volume high-speed wet submersible pump has been designed. This article provides comparison and analysis for nine combination cases of different matching laws between the impeller blade number Z 1 (Z 1 = 5, 6, 7) and the diffuser vane blade number Z 2 (Z 2 = 8, 9, 10). The comparison of the pump performance and inner flow characters, such as the head, efficiency, radial force, and pressure pulsation coefficient, at different blade number matching of impeller and diffuser has been studied by the computational fluid dynamics software CFX. These are solved through the three-dimensional unsteady Reynolds-averaged Navier-Stokes equations with the shear-stress transport k-v turbulence model. Furthermore, the computational fluid dynamics method is validated by experimental data collected in the laboratory. The results show that the combination of blade number of impeller and diffuser vane has a significant effect on the behavior. The steady analysis of combinations indicates that an increased efficiency occurs along with the reduced blade number. From the unsteady perspective, the 7 + 8 (Z 1 = 7, Z 2 = 8) case has the lowest fluctuation and relatively small radial force. In conclusion, the above results can provide reference for choosing blade numbers matching law between impeller and diffuser vane of the high-speed rescue pump.

Determination of the rational number of blades of the centrifugal wheel of a submersible pump

“…However, there are still unresolved issues related to the strength of the centrifugal wheel and the increase in its metal content. In [4], the mutual influence of the number of wheel blades 5, 6, 7 and the number of diffuser blades 8, 9, 10 was considered. As a result of research based on numerical modeling, it was found that the case 7+8 has a minimum wheel oscillation, but the influence of pulsation of the forces on the rotor -wheel system was not identified, and this is important, since the dynamic characteristics of the rotor affect both the efficiency value and the strength of the shaft as a whole.…”

Experimental investigation of cavitation characteristics for a high-speed inducer with a great flow rate

“…To ensure the stability and reliability of the entire unit, a mine rescue pump with a high flow rate, head, and rotating speed must be designed. [1][2][3] Cavitation performance generally affects the high-speed pump, 4,5,12,23 and induces flow vibration and noise due to the phase transition and change in vortex structure. [6][7][8] Numerous studies and applications related to high-speed pumps have indicated that installing an inducer on an upstream impeller is the best for improving the anticavitation ability.…”

Study of the influence of the design of a centrifugal wheel on the pressure characteristics of a multistage pump

“…The approach of choosing a wheel by strength parameters was used in [3], but it was based only on changes in the speed of rotation of the rotor shaft, but not on the effect of flow pulsation and the strength of the centrifugal wheel, which depends on the choice of the number of blades. The authors of [4] presented the results of studying the effect of natural vibration frequencies of a centrifugal wheel on the shaft strength caused by the difference in the number of wheel blades and diffuser. The work [5] was devoted to calculating the strength of disks and blades based on the use of a modified method of successive approximations in shifted Chebyshev polynomials.…”