Mixed-flow pump

Abstract

The invention discloses a mixed-flow pump. The mixed-flow pump comprises a volute and an impeller; the outlet of the volute is communicated with the inlet of the impeller; the volute is inclined relative to a center line at a rotation shaft of the impeller so that a center line of the outlet of the volute has a flowing taper angle theta relative to a center line at the rotation shaft of the impeller. The inclination of the outlet of the volute is capable of playing a role in improving the incoming flow at the inlet of the mixed-flow pump as a turbine impeller, thereby decreasing the hydraulicloss and enhancing the performance of the mixed-flow pump as a turbine set. The mixed-flow pump can be widely applied in the large-flow and low-water head micro hydropower stations.

Description

technical field [0001] The invention relates to the fields of liquid pressure residual energy recovery and small-scale hydropower generation, in particular to a mixed-flow pump used as a turbine in a large-flow, low-head hydropower station. Background technique [0002] Liquid pressure energy is a renewable clean energy. With the increasing demand for energy in social development and the increasing awareness of energy conservation, the development and utilization of decentralized low-power liquid pressure energy will play an important role in building a resource-saving and environment-friendly society. The method of using the reverse pump to recover the residual pressure of the turbine has the advantages of small size, simple structure, convenient operation and maintenance, etc., and is widely used in energy-saving fields such as industrial processes and small hydropower. [0003] Different from the conventional Francis turbine, the mixed flow pump used as a turbine is usua...

AI Technical Summary

Problems solved by technology

[0004] Since the mixed-flow pump is used as the inlet of the turbine impeller, there is a certain inclination angle, so after the fluid flows out radially from the outlet of the volute, the velocity changes in the direction and enters the impeller flow channel, causing a certain loss in the gap area, which affects the overall efficiency of the unit

At the same time, the gap between the outlet of the volute and the rim of the rear cover plate of the mixed-flow impeller is relatively large, resulting in a relatively large flow area between the gap flow field of the rear pump chamber and the mainstream flow field. Further increase the impact loss of the gap flow field in the rear pump chamber to the mainstream flow field

Therefore, the current mixed-flow pump is used as a turbine volute structure, which affects the efficiency of the unit to a certain extent.

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