A new type of ultra-low specific speed pump-turbine

Abstract

The invention discloses a novel ultralow specific speed pump turbine. The novel ultralow specific speed pump turbine comprises a volute (4), a rotating wheel (1), a second-grade guide vane zone (3) and an exhaust water pipe (2), and water flow in a flow channel of the volute is axially input and output. The volute (4) is internally provided with multiple first-grade guide vanes (5) at the negativecurvature, and the first-grade guide vanes (5) are uniformly distributed in a single-row annular manner. The rotating wheel (1) comprises multiple rotating paddle type vanes (6). The second-grade guide vane zone (3) comprises multiple symmetrical whale-shaped movable guide vanes (7). The pump turbine can operate efficiently under two working conditions, namely power generation and water pumping;and a unit achieves good and stable performance when operating in a typical working condition transition process.

Description

technical field [0001] The invention belongs to the technical field of hydraulic machinery, in particular to a novel ultra-low specific speed water pump turbine. Background technique [0002] According to statistics, the existing pumped storage power station is equipped with reversible units to bear more than 7.4 million kilowatts of power, and because the reversible unit has the characteristics of two-way operation (power generation under the turbine working condition, pumping water under the pump working condition), the pump turbine is the first choice for the hydropower station under construction. model. [0003] Due to the frequent start and stop of the pump turbine system, such as large increase and decrease of load, accidental load shedding, and power generation transfer, the conversion process of working conditions is changeable and complicated. During the operation, there will be pressure pulsation, abnormal vibration, excessive swing, lifting, and sweeping. and oth...

AI Technical Summary

Problems solved by technology

[0005] Chinese patent application CN201611149428.8 discloses an axial-flow pump-turbine with a dual-clutch mechanism. Both the runner and the blades have a clutch structure, so that the pump-turbine can reversibly operate in two working conditions of power generation and pumping, but the design of the structure is complicated. It is not convenient for maintenance in the future, and the interchangeable function of the guide vane and the runner is in two working conditions, and there will be problems such as whether there is a wide common high-efficiency zone in the two working conditions, etc.

Chinese patent application CN201610015261.X discloses a pump-turbine and its usage method. Two times the number of small movable guide vanes are arranged before the fixed guide vanes to control the flow of the unit. From the perspective of structural design, it can effectively improve the instability of the flow field in the unit operating under non-design conditions

Images