Adjustable water pump water turbine tailrace based on working condition optimization

Abstract

This invention discloses an adjustable draft tube for a pump-turbine based on optimal operating conditions, comprising a tapered section, an elbow section, a first rotating mechanism, and a second rotating mechanism. One end of the tapered section is connected to the turbine runner via the first rotating mechanism, and the other end is connected to the elbow section via the second rotating mechanism. Adjusting the first and second rotating mechanisms adjusts the angle between the centerline of the tapered section and the centerline of the turbine runner. By rotating the first and second rotating mechanisms, this invention adjusts the angle θ of the tapered section, which can significantly reduce the pressure pulsation amplitude of the pump-turbine, thereby making the pump-turbine operation more stable.

Description

Technical Field

[0001] This invention relates to an adjustable water pump turbine tailrace pipe based on operating condition optimization, belonging to the technical field of water turbine tailrace pipes. Background Technology

[0002] A pumped-storage hydroelectric generator is a type of hydroelectric generator that can both generate electricity and pump water. Its hydraulic turbine component mainly consists of a pump-turbine. The water-passing components within the pump-turbine that directly affect energy conversion are called the pump-turbine flow passage components. The flow passage system mainly comprises the volute, guide vanes, runner, and draft tube.

[0003] Hydropower is a relatively stable part of the power system, and mixed-flow turbines are the most widely installed type of turbine in hydropower stations.

[0004] With the increasing proportion of intermittent renewable energy sources such as wind and solar power in the power grid, the stability of the grid is significantly impacted. To achieve grid frequency regulation and load equalization, pump-turbines undergo rapid and frequent load changes and start-ups / shutdowns, causing pumped storage units to frequently deviate from their rated operating conditions to adjust grid parameters. When pump-turbines operate under these conditions, the internal flow field cannot guarantee optimal flow conditions, easily leading to unstable flow phenomena such as impacts, backflow, and secondary flows. This generates various vortex flows, such as partial load vortex bands, high load vortex bands, erosion cavitation, flow separation, and fatigue problems, accelerating pump-turbine fatigue wear, reducing the unit's hydraulic performance, and in severe cases, threatening the safe operation of the unit and even the entire power plant.

[0005] The tailrace pipe is an important flow passage component of a pump-turbine, playing an irreplaceable role in the pump-turbine. It guides the water flow while also bearing alternating stress loads. It is of paramount importance for studying the internal flow field of the pump-turbine and optimizing the design of the pump-turbine, and has a significant impact on the hydraulic performance of the pump-turbine. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the defects of the prior art and provide an adjustable water pump turbine tailrace pipe based on working condition optimization. By rotating the first rotating mechanism and the second rotating mechanism, the included angle θ of the cone pipe section can be adjusted, which can significantly reduce the pressure pulsation amplitude of the water pump turbine, thereby making the water pump turbine more stable during operation.

[0007] Preferably, the present invention provides an adjustable water pump turbine tailrace pipe based on operating condition optimization, including a tapered pipe section, an elbow section, a first rotating mechanism and a second rotating mechanism. One end of the tapered pipe section is connected to the runner through the first rotating mechanism, and the other end of the tapered pipe section is connected to the elbow section through the second rotating mechanism. Adjusting the first rotating mechanism and the second rotating mechanism adjusts the angle between the centerline of the tapered pipe section and the centerline of the runner.

[0008] Preferably, the first rotating mechanism includes a first bending rod, a first connecting rod, a second connecting rod, a second bending rod, a rotating wheel, a rotating shaft, a U-shaped rod, and a fixed rod. One end of the first bending rod is fixedly connected to one end of the first connecting rod, the other end of the first connecting rod is fixedly connected to the second connecting rod, and the other end of the second connecting rod is fixedly connected to the second bending rod. The rotating wheel rotatably connects the first bending rod, the second bending rod, the U-shaped rod, and the fixed rod through the rotating shaft. The U-shaped rod is located on the side of the second bending rod away from the first bending rod.

[0009] Preferably, the first and second bending rods are V-shaped rods.

[0010] Preferably, it includes a diffuser section, which is connected to the tapered tube section via a second rotating mechanism.

[0011] Preferably, the cross-sectional profile of the tapered tube section is circular.

[0012] Preferred, the angle θ between the centerline of the adjusting tapered tube section and the centerline of the impeller is determined using the following formula:

[0013]

[0014] In the formula, y is the height of the tapered tube section, and f t These are the training parameters.

[0015] Preferably, the range of θ adjustment is from -0.25π to 0.25π.

[0016] The beneficial effects achieved by this invention are as follows:

[0017] 1. By rotating the first and second rotating mechanisms, the included angle θ of the cone tube section can be adjusted, which can significantly reduce the pressure pulsation amplitude of the water pump turbine, thereby making the water pump turbine more stable during operation.

[0018] 2. By adjusting the included angle θ of the cone tube section, the vortex morphology of the draft tube of the pump turbine can be improved, thereby making the pump turbine more stable during operation.

[0019] 3. By controlling the adjustable cone section through the rotating mechanism, the included angle θ of the cone section can be adjusted according to the operating conditions of the water pump and turbine, thereby achieving optimal flow state of the tailrace pipe based on the operating conditions. Attached Figure Description

[0020] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 These are cross-sectional views of some embodiments of this application;

[0022] Figure 2 These are structural diagrams of the tapered tube section and the rotating mechanism in some embodiments of this application;

[0023] Figure 3 This is a structural diagram of the first rotating mechanism in some embodiments of this application;

[0024] Figure 4 This is a structural diagram of the first rotating mechanism in some embodiments of this application;

[0025] Figure 5 This is a schematic diagram of pressure pulsation when the tapered tube section is not rotating in some embodiments of this application;

[0026] Figure 6 This is a schematic diagram illustrating the pressure pulsation after the tapered tube section rotates, as shown in some embodiments of this application.

[0027] The following are the meanings of the reference numerals in the attached diagram: 1-Rotating wheel; 2-Conical tube section; 3-Bent elbow section; 4-Diffuser section; 5-First rotating mechanism; 6-Second rotating mechanism; 61-First bending rod; 62-First connecting rod; 63-Second connecting rod; 64-Second bending rod; 65-Rotating wheel; 66-Rotating shaft; 67-U-shaped rod; 68-Fixing rod. Detailed Implementation

[0028] To facilitate the explanation of the technical solution of this application, some concepts involved in this application will be explained first below.

[0029] It should be noted that if there are directional indicators (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention, they are only used to explain the relative positional relationship and movement of the components in a certain specific posture. If the specific posture changes, the directional indicator will also change accordingly.

[0030] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" and "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. If the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.

[0031] See Figure 1 This application provides an adjustable draft tube for a pump-turbine based on operating condition optimization, comprising a tapered section 2, an elbow section 3, a first rotating mechanism 5, and a second rotating mechanism 6. One end of the tapered section 2 is connected to the runner 1 via the first rotating mechanism 5, and the other end of the tapered section 2 is connected to the elbow section 3 via the second rotating mechanism 6. Adjusting the first rotating mechanism 5 and the second rotating mechanism 6 adjusts the angle θ between the centerline of the tapered section 2 and the centerline of the runner 1. The angle θ is dynamically adjusted by the control system based on the operating conditions of the pump-turbine. The angle θ of the adjustable tapered section is jointly adjusted and controlled by the first rotating mechanism and the second rotating mechanism. The rotating mechanism contacts the adjustable tapered section and adjusts the tapered section by rotational feeding.

[0032] In this embodiment, the first rotating mechanism 5 includes a first bending rod 61, a first connecting rod 62, a second connecting rod 63, a second bending rod 64, a rotating wheel 65, a rotating shaft 66, a U-shaped rod 67, and a fixed rod 68. One end of the first bending rod 61 is fixedly connected to one end of the first connecting rod 62, the other end of the first connecting rod 62 is fixedly connected to the second connecting rod 63, and the other end of the second connecting rod 63 is fixedly connected to the second bending rod 64. The rotating wheel 65 rotatably connects the first bending rod 61, the second bending rod 64, the U-shaped rod 67, and the fixed rod 68 through the rotating shaft 66. The U-shaped rod 67 is located on the side of the second bending rod 64 away from the first bending rod 61.

[0033] In this embodiment, the first bending rod 61 and the second bending rod 64 are V-shaped rods.

[0034] like Figure 2 As shown, the cross-sectional profile of the tapered tube section is circular, and the two rotating mechanisms are located at both ends of the tapered tube section.

[0035] like Figure 3 As shown, the rotating mechanism can adjust the tapered tube section by rotating the feed mechanism.

[0036] like Figure 4 As shown, the maximum pressure pulsation when the tapered tube section is not rotating is 1.2%.

[0037] like Figure 5 As shown, the maximum pressure pulsation after the tapered tube section rotates is 0.4%.

[0038] like Figure 4 and Figure 5 As shown in the figure, the comparison shows that after adjusting with a rotating mechanism, the pressure pulsation of the water pump turbine is significantly reduced, which can effectively optimize the hydraulic performance of the water pump turbine.

[0039] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0040] Other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention described herein. This application is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not invented herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of the invention are indicated by the following claims.

[0041] The above specific embodiments further illustrate the purpose, technical solution and beneficial effects of this application. It should be understood that the above are only specific embodiments of this application and are not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made on the basis of the technical solution of this application should be included within the scope of protection of this application.

Claims

1. An adjustable water pump turbine tailrace pipe based on operating condition optimization, characterized in that, The system includes a tapered tube section (2), a bent section (3), a first rotating mechanism (5), and a second rotating mechanism (6). One end of the tapered tube section (2) is connected to the rotating wheel (1) via the first rotating mechanism (5), and the other end of the tapered tube section (2) is connected to the bent section (3) via the second rotating mechanism (6). The angle between the centerline of the tapered tube section (2) and the centerline of the rotating wheel (1) is adjusted by adjusting the first rotating mechanism (5) and the second rotating mechanism (6). The angle θ between the centerline of the tapered tube section (2) and the centerline of the rotating wheel (1) is determined by the following formula: ； In the formula, y is the height of the tapered tube section, and f t These are the training parameters.

2. The adjustable pump-turbine tailrace pipe based on operating condition optimization according to claim 1, characterized in that, The first rotating mechanism (5) includes a first bending rod (61), a first connecting rod (62), a second connecting rod (63), a second bending rod (64), a rotating wheel (65), a rotating shaft (66), a U-shaped rod (67), and a fixed rod (68). One end of the first bending rod (61) is fixedly connected to one end of the first connecting rod (62), the other end of the first connecting rod (62) is fixedly connected to the second connecting rod (63), and the other end of the second connecting rod (63) is fixedly connected to the second bending rod (64). The rotating wheel (65) is rotatably connected to the first bending rod (61), the second bending rod (64), the U-shaped rod (67), and the fixed rod (68) through the rotating shaft (66). The U-shaped rod (67) is located on the side of the second bending rod (64) away from the first bending rod (61).

3. The adjustable pump-turbine tailrace pipe based on operating condition optimization according to claim 2, characterized in that, The first bending rod (61) and the second bending rod (64) are V-shaped rods.

4. The adjustable pump-turbine tailrace pipe based on operating condition optimization according to claim 1, characterized in that, The cross-sectional profile of the tapered tube section is circular.

5. The adjustable pump-turbine tailrace pipe based on operating condition optimization according to claim 1, characterized in that, The range of θ adjustment is from -0.25π to 0.25π.

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