Small-hydropower axial flow turbine device

Abstract

The invention discloses a small-hydropower axial flow turbine device. The small-hydropower axial flow turbine device comprises an upper seat ring (1), a lower seat ring (3), sixteen movable guide vanes (2), a support cover (6), a bottom ring (7), a runner chamber (4), a hub (8), a runner cone (9), three blades (10) fixedly mounted on the hub and a straight-cone-shaped draft tube (5), wherein the upper seat ring (1) and the lower seat ring (3) are provided with the guide vanes. The center circle diameter of a water guide mechanism is large, the movable guide vanes and the upper and lower seat rings extend outwards by certain size from a guide vane inlet, the sixteen movable guide vanes which are large in opening are adopted, the runner is high in running speed, inlet and outlet water flow angles of the outer edges of the blades are large, the hub ratio of the runner chamber is low, excess flow is large, the shape contracts at an outlet of the runner and starts to spread again from the straight-cone-shaped draft tube, and numerical simulation shows that efficiency of a turbine can reach 85%. The small-hydropower axial flow turbine device is simple in structure, small in size, convenient to process, low in economic cost and high in efficiency, can be used for low-water-head and high-flow power stations for power generation and can also be used for small-hydropower synergistic expansion modification in the early stage.

Description

technical field [0001] The invention belongs to the technical field of fluid machinery, and in particular relates to an axial-flow water turbine suitable for a small power station with low water head and high flow. [0002] Background technique [0003] In order to develop small hydropower and prosper the rural economy, my country built a large number of small power stations in the early days. Among them, the development of low-head hydropower resources of 2-6m mainly uses axial-flow turbines, but the average efficiency of its operation is low, and its flow rate is low. Components are prone to cavitation damage and vibration. Since it has been in operation, although it has been repaired during the period, the deformation of the blades is relatively large, the vibration and cavitation are very serious, and the output and efficiency are not ideal. It needs to be improved and expanded. [0004] Considering the transformation cost, most power stations choose not to change the o...

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Problems solved by technology

[0005] However, the existing axial flow turbines are not efficient when operating at a water head below 5m, and it is difficult to achieve the goal of improving efficiency and expanding capacity of low water head power stations. At this time, it is necessary to Develop high-efficiency low-head axial flow turbines to meet demand

[0006]High-efficiency low-head axial-flow turbine has simple structure, small size, and low economic cost. When the runner diameter of tubular turbine is less than 2.5 m, the Difficult to manufacture, complex civil structure

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