CN105240184A - Ultra-low water head axial flow turbine - Google Patents

Abstract

An ultra-low head axial flow turbine, including a guide vane, a runner and a draft tube, the guide vane is composed of a fixed guide vane (1), an inner support wall (2) and an outer support wall (3). It is used to guide the water flow into the runner evenly and with rotation; the runner is composed of runner blades (4), hub (5), discharge cone (6) and runner chamber (7). The energy can be converted into rotational mechanical energy; the draft tube (8) is in the shape of a straight cone, and is used to guide the water flowing out from the runner to the downstream and recover a part of the water flow. The invention has the advantages of simple structure, low manufacturing cost, convenient installation and maintenance, and high reliability of the device; it has excellent hydraulic performance in a wide water head range, and can be used in small hydropower, tides, ocean currents, wave energy and other ultra-low water head applications. Renewable energy development.

Description

An Ultra-low Head Axial Flow Turbine

technical field

The invention relates to the technical field of water turbines, in particular to an ultra-low head axial flow water turbine.

Background technique

Energy is the basic driving force for social development and economic growth, and the basis for human survival. Along with economic development and population growth, energy consumption has increased significantly, and fossil energy resources are increasingly exhausted. The use of fossil energy has also caused great damage to the natural environment, had a significant impact on the global natural ecosystem, and brought many problems to the survival and development of human society. Therefore, the development and utilization of renewable energy are increasingly valued by the international community.

River energy, tidal energy, ocean current energy, and wave energy among renewable energy sources are ultra-low-head or even zero-head energies with abundant reserves, but they are still in the early stages of development and urgently need to be developed and utilized by us through advanced technical means to serve mankind. benefit.

Compared with conventional turbines, ultra-low head turbines have a lower head, smaller size, lower efficiency and output power, and harsher working environments and conditions. Therefore, higher requirements are put forward for the efficiency, reliability and cavitation performance of its energy conversion. This also increases the difficulty in the design of this type of water turbine and the development of ultra-low head energy.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the prior art and provide an ultra-low head axial flow water turbine with simple structure, convenient installation and maintenance, and wide high efficiency area.

An ultra-low head axial flow turbine, including a guide vane, a runner and a draft tube. The guide vane is composed of a fixed guide vane 1, an inner support wall 2 and an outer support wall 3, and is used to guide the water flow evenly and with Rotationally enters the runner; the runner is composed of runner blades 4, hub 5, drain cone 6 and runner chamber 7, and is used to convert water energy into rotational mechanical energy; the draft tube 8 is a straight cone Shaped to direct the water flow from the runner downstream and recover a portion of the water flow.

The fixed guide vane 1 is an equal-thickness curved surface, the inlet and outlet water edges of the fixed guide vane 1 are straight lines, the head is elliptical, and the tail is parabolic; the inner support wall 2 and the outer support wall 3 are both It is conical, and the two conical surfaces have the same vertex.

The runner blade 4 is fixed paddle type, the hub 5 is cylindrical, the water discharge cone 6 is parabolic, and the runner chamber 7 is cylindrical.

The runner blade adopts NACA66 (MOD) airfoil (National Advisory Committee for Aeronautics, NACA for short) with good cavitation performance.

The ultra-low head axial flow turbine is arranged vertically or horizontally.

The ultra-low head axial flow turbine is used for bidirectional power generation.

The ultra-low head axial-flow turbine is used for the development of renewable energy such as tidal energy and ocean current energy, where the direction of water flow changes back and forth.

Compared with the prior art, the invention has the advantages of simple structure, low manufacturing cost, convenient installation and maintenance, and high reliability of the device; it has excellent hydraulic performance in a wide water head range, and can be used in small hydropower, Development of ultra-low head renewable energy such as tides, ocean currents, and wave energy.

Description of drawings

Figure 1 is a schematic diagram of the overall structure of the device of the present invention.

Fig. 2 is a three-dimensional structural schematic diagram of a fixed guide vane.

Fig. 3 is a schematic diagram of different cross-sectional airfoils of the fixed guide vane.

In the figure, 1 is a fixed guide vane, 2 is an inner support wall, 3 is an outer support wall, 4 is a runner blade, 5 is a wheel hub, 6 is a discharge cone, 7 is a runner chamber, and 8 is a draft tube.

detailed description

The present invention will be further described below with reference to the description of the drawings and specific embodiments, but it is not intended to limit the scope of protection thereof.

As shown in Figure 1-3, an ultra-low head axial flow turbine includes a guide vane, a runner and a draft tube 8; the guide vane is composed of a fixed guide vane 1, an inner support wall 2 and an outer support wall 3, Its function is to guide the water flow into the runner evenly and with rotation; the runner is composed of runner blades 4, hub 5, drain cone 6 and runner chamber 7, and is used to convert water energy into rotational mechanical energy; draft tube 8 is a straight cone, which is used to lead the water flowing out from the runner to the downstream and reclaim a part of the water flow.

The runner can be connected with an induction asynchronous generator or a permanent magnet synchronous generator to form a hydroelectric generator set, realizing the complete conversion of water energy/tidal energy/ocean energy-mechanical energy-electric energy.

The fixed guide vane 1, the inner support wall 2, the outer support wall 3, the wheel hub 5, the discharge cone 6, the runner chamber 7, and the draft tube 8 can all be made of suitable materials such as equal-thickness formed steel plates or plastic steel. The runner blade 4 can be polished after casting or directly cut from a steel plate.

The water turbine of the present invention can be arranged vertically or horizontally.

The water turbine of the invention can generate electricity in both directions. During reverse power generation, the water flow enters from the draft tube 8, and when the water flow flows around the runner blade 4, energy is transferred to the runner, and the water flow after doing work flows out from the guide vane.

According to different working environments and flow conditions, the size of the matching turbine can be selected, and the parameters of the turbine can be optimized, such as the number of guide vanes, runner blades, hub ratio, draft tube cone angle, etc., to obtain the best conversion efficiency.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which the present invention belongs can make various modifications or supplements to the described specific embodiments or adopt similar methods to replace them, but they will not deviate from the spirit of the present invention or go beyond the definition of the appended claims range.

Although this article uses many terms such as fixed guide vane 1, inner support wall 2, outer support wall 3, runner blade 4, hub 5, discharge cone 6, runner chamber 7, draft tube 8, etc., they are not The possibility of using other terms is not excluded. These terms are used only for the purpose of describing and explaining the essence of the present invention more conveniently; interpreting them as any kind of additional limitation is against the spirit of the present invention.

Claims (7)

1. an extra low head axial flow hydraulic turbine, comprise stator, runner and draft tube, it is characterized in that: described stator is made up of fixed guide vane (1), inner support wall (2) and outer support wall (3), for guiding uniform fluid flow and with rotationally entering runner; Described runner is made up of, for water can be converted to rotating mechanical energy runner bucket (4), wheel hub (5), draft cone (6) and runner envelope (7); Described draft tube (8) is straight-tapered, for guiding the current flowed out from runner into downstream and reclaiming a part of water flow.

2. extra low head axial flow hydraulic turbine as claimed in claim 1, it is characterized in that: described fixed guide vane (1) is uniform thickness curved surface, the turnover waterside of fixed guide vane (1) is straight line, and head is oval, and afterbody is parabola shaped; Described inner support wall (2) and outer support wall (3) are taper, and two conical surfaces summit altogether.

3. extra low head axial flow hydraulic turbine as claimed in claim 1, it is characterized in that: described runner bucket (4) is for determine paddle, wheel hub (5) is for cylindrical, and draft cone (6) is for parabola shaped, and runner envelope (7) is for cylindrical.

4. extra low head axial flow hydraulic turbine as claimed in claim 1, is characterized in that: described runner bucket adopts NACA66 (MOD) aerofoil profile.

5. extra low head axial flow hydraulic turbine as claimed in claim 1, it is characterized in that: described extra low head axial flow hydraulic turbine, is vertical or horizontal layout.

6. extra low head axial flow hydraulic turbine as claimed in claim 1, is characterized in that: for two-way generating.

7. the extra low head axial flow hydraulic turbine as described in claim 1-6, is characterized in that: the renewable energy sources exploitation that the water (flow) direction for tidal energy, energy by ocean current back and forth changes.