FLOW GUIDING SEDIMENT BYPASS TUNNEL GATE STRUCTURE WITH SELF-ADAPTIVE INLET ADJUSTMENT

Abstract

A gate structure of flow guiding sediment bypass tunnel with self-adaptive inlet adjustment the gate structure comprises a sediment bypass tunnel main body, wherein: the sediment bypass tunnel main body comprises a second revolution wheel, a second braking rim, a top water stopper plate and a weir, a second regulator is provided at a front side of the sediment discharge tunnel, the second revolution wheel is provided at a top portion of the second regulator, a top portion of the second revolution wheel is welded with the second valve lever, the second valve lever is connected with the top portion of the second regulator, and by providing the flow guiding structure at the bottom portion bottom water flows with higher sediment concentrations can be guided into the tunnel; and the altitude of the flow guiding inlet at the bottom portion can be automatically controlled with the gate structure.

Claims

1. A flow guiding sediment bypass tunnel gate structure with self-adaptive inlet adjustment, comprises a sediment bypass tunnel main body (1), wherein: the sediment bypass tunnel main body (1) comprises a second revolution wheel (3), a second braking rim (5), a top water stopper plate (7) and a weir (8), wherein a second regulator (2) is provided at a front side of the sediment bypass tunnel main body (1), the second revolution wheel (3) is provided on a top portion of the second regulator (2), a top portion of the second revolution wheel (3) is welded with a second valve lever (4), the second valve lever (4) is connected with a top portion of the second regulator (2), a bottom portion of the second valve lever (4) is rotatably connected with a top portion of the second braking rim (5), the weir (8) is provided at a side of the second regulator (2), lateral water stopper plates (6) are provided at both sides of the weir (8), sides of top portions of the lateral water stopper plates (6) are welded with both ends of the top water stopper plate (7), the top water stopper plate (7) is provided on the weir, a first regulator (9) is provided at a bottom portion of the weir (8), a first braking lever (11) is connected with the first regulator (9), a controller (12) is provided at a top portion of the first braking lever (11), a bottom portion of the first braking lever (11) is connected rotatably with the first braking rim (10), and a drive device and a monitor system are provided in the controller (12).

2. The flow guiding sediment bypass tunnel gate structure with self-adaptive inlet adjustment according to claim 1, wherein the bottom portion of the weir is lower than a bottom portion of the sediment bypass tunnel main body (1), and a side of the weir (8) is step-shaped.

3. The flow guiding sediment bypass tunnel gate structure with self-adaptive inlet adjustment according to claim 1, wherein an experiment method of the sediment bypass tunnel comprises the following steps: step one: configuring an open sediment bypass tunnel to be the sediment bypass tunnel main body (1) with flow regulation at a bottom portion, guiding a water flow at the bottom portion with a high sediment content to flow into the sediment bypass tunnel main body (1), during sediment discharge at an intermediate portion of a reservoir, providing the sediment bypass tunnel main body (1) with flow regulation at the bottom portion, wherein an intake of the sediment bypass tunnel main body (1) comprises a guiding structure and a weir; step two: obtaining calculation equations for vertical distribution features and a layering and inflection height of sediment contents under different sediment inflow conditions in weak force water flows of reservoirs, targeting at features of the reservoirs of weak water flow and fine sediment particles, conducting at least one flume test for the vertical distribution features of the sediments in weak force and fine particle water flows, wherein a width of the flume is 20 cm, a height of the flume is 25 cm, and a length of the flume is 3.5 m, a step at a bottom portion of the flume is variable, a biggest affordable flow rate 8 m.sup.3/h, and a variable range of a slope at the bottom portion of the flume is 0-1%; step three: given a particle diameter of suspended sediments in common reservoirs (0.001 mm to 0.1 mm), a gradation of sand is used in tests, with a median particle size of 0.065 mm, during the tests, different combinations of inlet flow rate, sediment contents and water depths are considered, sediment concentration along a vertical direction is measured at a hydrographic section according to a ten-point method, wherein measurement of the sediment contents is done at ten points dividing water along a water depth direction, and the sediment contents showed obvious stratification at an upper layer and a lower layer; step four: configuring a flow guiding structure of the flow guiding sediment bypass tunnel to be an adjustable gate, openness of the adjustable gate is adjustable adaptively according to water flows and sediment inflows, thus a height of a bottom portion of the adjustable gate is located at the layering and inflection point of sediment concentrations in the water flows, so to reach precise and efficient sediment discharge effects.

4. The flow guiding sediment bypass tunnel gate structure with self-adaptive inlet adjustment according to claim 1, wherein in the step three, based on basic theories of river mechanics, features of the sediment concentrations along the vertical direction, a depth of the layering and inflection point of the sediment concentrations along the vertical direction of fine particle sediments H.sub.0 is correlated to factors, namely, a flow rate v, a water depth h, the sediment concentrations s and the median particle size D, and conventional parameters, namely, a volume weight of sediments s, a volume weight of water and gravitational acceleration g, and a relationship is shown here: $\begin{array}{cc}{H}_0=f\left(h,v,D,s,s,,g\right).& \left(1\right)\end{array}$

5. The flow guiding sediment bypass tunnel gate structure with self-adaptive inlet adjustment according to claim 4, wherein, to conduct data regression conveniently, the foregoing factors are to be non-dimensional-normalized, therefore a sediment incipient motion formula (2) and a sediment-carrying capacity formula (3) are given.

6. The flow guiding sediment bypass tunnel gate structure with self-adaptive inlet adjustment according to claim 5, wherein the sediment incipient motion formula is: $\begin{array}{cc}{v}_c={\left(\frac{h}{D}\right)}^{0.14}\sqrt{17.6D\frac{{}_s-}{}+6.05{10}^{-7}+\frac{10+h}{D^{0.72}}}& \left(2\right)\end{array}$ in the formula: ve is a competent velocity of the sediments.

7. The flow guiding sediment bypass tunnel gate structure with self-adaptive inlet adjustment according to claim 5, wherein the sediment-carrying capacity formula (3) is: $\begin{array}{cc}{S}_m=K{\left\{\frac{v^3}{\mathrm{gh}}\right\}}^m& \left(3\right)\end{array}$ in the formula: S.sub.m is a sediment-carrying capacity, k and m are constants, for the reservoirs usually 0.25 and 0.92 are used, and is a sediment settling velocity, and is correlated with D.

8. The flow guiding sediment bypass tunnel gate structure with self-adaptive inlet adjustment according to claim 7, wherein substituting the formula (3) into the formula (1) for non-dimensional normalization, and the following equation is obtained: $\begin{array}{cc}{H}_0/h=f\left(v/v_c,s/s_m\right).& \left(4\right)\end{array}$

9. The flow guiding sediment bypass tunnel gate structure with self-adaptive inlet adjustment according to claim 2, wherein by conducting non-dimensional regression and least squares regression for data of the flow rate, the water depth, the sediment concentration and the inflection point depth, a formula of the inflection point depth of the sediment concentration (5) is obtained: $\frac{h}{H_0}=44.39{\left(\frac{v}{v_0}\right)}^{-1.189}{\left(\frac{s}{s_m}\right)}^{-0.566}$ wherein a correlation coefficient is 0.89.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0023] FIG. 1 is a cross section diagram showing the present invention;

[0024] FIG. 2 is a diagram showing vertical distribution of suspended sediments in natural rivers;

[0025] FIG. 3 is a diagram showing vertical distribution of sediment concentrations;

[0026] FIG. 4 is a diagram showing a gradation of sediments;

[0027] FIG. 5 is a diagram showing sediment discharge at intermediate portions of a reservoir; and

[0028] FIGS. 6A-6C are plan views of the reservoir.

[0029] In the drawings: 1 sediment bypass tunnel; 2 second regulator; 3 second revolution wheel; 4 second valve lever; 5 second braking rim; 6 lateral water stopper plate; 7 top water stopper plate; 8 weir; 9 first regulator; 10 first braking rim; 11 first valve lever; and 12 controller.

EMBODIMENTS

[0030] Hereinafter a complete and clear description will be given to the technical solutions of embodiments of the present invention in conjunction with the drawings of the embodiments of the present invention; apparently, the embodiments given here are only some of the embodiments of the present invention rather than all. Based on the embodiments described in the present invention, all other embodiments obtained by those of ordinary skill without paying creative effort shall fall into the protection scope of the present invention.

Embodiment 1

[0031] A gate structure of a flow guiding sediment bypass tunnel with self-adaptive inlet adjustment, comprises a sediment bypass tunnel main body 1, wherein: the sediment bypass tunnel main body 1 comprises a second revolution wheel 3, a second braking rim 5, a top water stopper plate 7 and a weir 8, wherein a second regulator 2 is provided at a front side of the sediment bypass tunnel 1, the second revolution wheel 3 is provided at a top portion of the second regulator 2, a top portion of the second revolution wheel 3 is welded with a second valve lever 4, the second valve lever 4 is connected with a top portion of the second regulator 2, a bottom portion of the second valve lever 4 is connected rotatably with a top portion of the second braking rim 5, the weir 8 is provided at a side of the second regulator 2, lateral water stopper plates 6 are provided at both sides of the weir 8, sides of top portions of the lateral water stopper plates 6 are welded with both ends of the top water stopper plate 7, the top water stopper plate 7 is provided above the weir 8, a first regulator 9 is provided at a bottom portion of the weir 8, the first regulator 9 is connected with a first valve lever 11, a controller 12 is connected at a top portion of the first valve lever 11, a bottom portion of the first valve lever 11 is connected rotatably with the first braking rim 10 and a drive device and a monitor system are provided in the controller 12.

[0032] The bottom portion of the weir 8 is lower than a bottom portion of the sediment bypass tunnel 1, and a side of the weir 8 is step-shaped.

[0033] A water depth H.sub.0 corresponding to an inflection point of vertical distribution of sediment concentration is to be obtained by calibration with special flume test and simulation, and an experiment method of the sediment bypass tunnel comprises the following steps: [0034] Step one: configuring common open sediment bypass tunnel to be the sediment bypass tunnel main body 1 with a flow guiding structure at a bottom portion, guiding water flows with higher sediment concentrations to flow into the sediment bypass tunnel main body 1, during sediment discharging at intermediate portions of a reservoir, providing the sediment bypass tunnel with the flow guiding structure at the bottom portion, wherein an inlet of the sediment bypass tunnel comprises a guiding structure and a cofferdam; [0035] Step two: researching to obtain calculation formulas of vertical distribution features of sediment concentrations and heights of layering and inflection points under different sediment incoming conditions in weak force water flows in a reservoir, conducting flume tests for concluding the vertical distribution features of sediment concentrations of weak force fine particle sediments, wherein the width of the flume is 20 cm, the height thereof 25 cm, the length thereof 3.5 m, the step at a bottom portion of the flume is variable, with a biggest affordable flow rate 8 m.sup.3/h, and a change range of the slope at the bottom portion of the flume is 0-1%;

[0036] Step three: considering a range of particle sizes of suspended sediments in common reservoirs (0.001 mm to 0.1 mm), tests were done with a gradation of sands, with a median particle size of 0.065 mm, experiment conditions were set considering different combinations of inlet flow rates, sediment concentrations and water depths, vertical distribution measurement of sediment concentrations was done at hydrographic sections by a ten-point method, wherein measurement of the sediment contents is done at ten points dividing water along a water depth direction, apparent vertical layering phenomena of the sediment concentrations were observed, as shown in FIG. 3, wherein an arrow therein shows where the inflection point is located, and from FIG. 3 the water depth H.sub.0 of the layering inflection point of the sediment concentrations can be obtained; [0037] Step four: configuring the flow guiding structure of the flow guiding sediment bypass tunnel to be an adjustable gate, and openness of the gate can be adaptively changed according to sediment incoming conditions, so that the height of the bottom portion of the gate is located at exactly the layering and inflection point of sediment concentrations of the incoming flow, so that precise and efficient sediment discharge effects can be realized.

[0038] In the step three, according to basic theories of river mechanics, vertical distribution features of sediment concentrations, that is, a layering and inflection depth H.sub.0 of vertical distribution of sediment concentration of fine particle sediments is correlated with factors such as inflowing rate v, water depth h, sediment concentrations s and median particle size D and conventional parameters, volume weight of sediments s, volume weight of water and gravitational acceleration g, that is:

[00006]$\begin{array}{cc}{H}_0=f\left(h,v,D,s,s,,g\right)& \left(1\right)\end{array}$

[0039] To make it easy to conduct data regression, non-dimensional normalization is to be done for the foregoing factors, therefore, a sediment incipient motion formula (2) and a sediment-carrying capacity formula (3) were introduced.

[0040] Wherein the sediment incipient motion formula (2) is:

[00007]$\begin{array}{cc}{v}_c={\left(\frac{h}{D}\right)}^{0.14}\sqrt{17.6D\frac{{}_s-}{}+6.05{10}^{-7}+\frac{10+h}{D^{0.72}}}& \left(2\right)\end{array}$

[0041] In the formula: vc is a sediment incipient motion flow rate.

[0042] Wherein the sediment-carrying capacity formula (3) is:

[00008]$\begin{array}{cc}{S}_m=K{\left\{\frac{v^3}{\mathrm{gh}}\right\}}^m& \left(3\right)\end{array}$

[0043] In the formula: s.sub.m is the sediment-carrying capacity, k and m are constants, usually 0.25 and 0.92 are used for reservoirs, and is a sediment settling velocity and is correlated with D.

[0044] Substituting the formula (3) into the formula (1) to conduct non-dimensional normalization, the following equation can be obtained:

[00009]$\begin{array}{cc}{H}_0/h=f\left(v/v_c,s/s_m\right)& \left(4\right)\end{array}$

[0045] By non-dimensional normalization and conducting least squares regression of the flow rate, water depth, sediment concentrations and inflection point depth data obtained in the tests, the formula of the inflection depth of the sediment concentration (5) is obtained:

[00010]$\begin{array}{cc}\frac{h}{H_0}=44.39{\left(\frac{v}{v_0}\right)}^{-1.189}{\left(\frac{s}{s_m}\right)}^{-0.566}& \left(5\right)\end{array}$

[0046] Wherein the correlation coefficient is 0.89.

Embodiment 2

[0047] Upper Arun hydroelectric plant lies on the upper reach of the Arun river, which is a trans-boundary river and is part of the Kosi or Sapt Koshi river system in Eastern Nepal, with a linear distance to Kathmandu approximately 220 km.

[0048] Over the years average flow rate of the Arun river is 217 m.sup.3/s, an average annual runoff is 6,860,000,000 m.sup.3, and average annual incoming sediments for the river system before the location of the dam in many years is 16,240,000 t, wherein annual suspended sediment transportation 13,810,000 t, sediment load 2,430,000 t, average annual suspended sediment concentration over the years is 2.01 kg/m.sup.3, and a median particle diameter of the suspended sediments is 0.057 mm. The hydraulic head of power generation by diverting water is bigger than 500 m, the volume of the water dam is around 5,070,000 m.sup.3, the reservoir-sediment ratio is around 0.4, therefore, the Arun river is characterized in being of high hydraulic head, small dam volume, big sediment contents and high sediment hardness.

[0049] To control sediment deposition, sediment bypass tunnels were provided, and inlets of the sediment bypass tunnels were provided at the left bank at 1 km upper stream from the dam, pressure tunnels were used, and the altitude of the bottom plates of the water inlets was 1610 m. When the reservoir level was 1625 m, the maximum discharge capacity of the sediment bypass tunnels were 822 m.sup.3/s.

[0050] The normal model 1:50 was used to simulate the sediment discharge effects of the reservoir. In the model, 1050 m.sup.3/s, 750 m.sup.3/s, 500 m.sup.3/s and 350 m.sup.3/s were used as the inflowing rate, the movable-bed test was conducted, during test, sediment concentration sampling was done at respectively an inlet A of the model (distance to the dam 1.67 km), an SBT outlet B (distance to the dam 1.2 km), an outlet C of the hydroelectric plant (distance from the dam 0 km), SBT upper stream D (distance to the dam 1.38 km), SBT lower stream E (distance to the dam 0.96 km), in front of the dam F (distance to the dam 0.1 km) and a bottom hole G (distance to the dam 0 km), drying the sediments and the sediment concentrations were tested to compare the sediment discharge effects with and without the guiding structure.

[0051] Comparing the SBT with the guiding structure with the SBT without the guiding structure, with the increase of the incoming flow, different extents of increase were observed in the SBT sediment concentrations (increases of the SBT sediment concentrations are respectively 9%, 4% and 2%), different extents of reduction were observed in sediment concentrations passing the turbines; and with the increase of the incoming flow, the changing magnitudes of the sediment concentrations of both the SBT and the hydroelectric plant were reduced.

[0052] With respect to the sediment discharge efficiency, comparing the SBT with the guiding structure with the SBT without the guiding structure, the sediment discharge efficiency was somehow improved, especially in big water flow big sediments conditions (1050 m.sup.3/s), and the sediment discharge efficiency for fine particle sediments was apparently improved, and for sediments smaller than 0.0062 mm the efficiency was improved from around 62% to around 78%; for small and medium water flow conditions, the improvement fell in between 3% to 8%, as big water flow and big sediments conditions had more layered flows. It can be seen that, with the guiding structure the sediment concentrations in the sediment bypass tunnels can be improved, sediment separation effects can be enhanced and they are especially suitable for use in big water flow and big sediments conditions with compelling sediment discharge demand.

[0053] Sediment discharge efficiency at different working conditions comparison table

TABLE-US-00001 Sediment discharge rate of groups Incoming of different particle sizes (%) flow rate Working Particle Power (m.sup.3/s) condition size (mm) SBT plant Total 350 With the 0.5~1.sup. 0 guiding 0.25~0.5 1.47 0.02 1.50 structure 0.125~0.25 7.37 5.65 13.02 0.062~0.125 12.30 18.93 31.23 0.03~0.062 16.61 31.34 47.95 0.01~0.03 18.92 39.01 57.93 0.01~0.001 20.70 45.52 66.22 With no 0.5~1.sup. 0.00 guiding 0.25~0.5 7.27 2.60 9.87 structure 0.125~0.25 7.54 11.49 19.03 0.062~0.125 11.51 30.36 41.87 0.03~0.062 13.88 44.96 58.84 0.01~0.03 14.87 50.73 65.60 0.01~0.001 15.90 55.37 71.26 500 With the 0.5~1.sup. 0.00 guiding 0.25~0.5 30.79 2.20 32.99 structure 0.125~0.25 40.42 5.98 46.40 0.062~0.125 48.22 13.88 62.11 0.03~0.062 51.43 21.08 72.51 0.01~0.03 51.92 23.41 75.34 0.01~0.001 51.79 26.53 78.32 With no 0.5~1.sup. 0.00 guiding 0.25~0.5 23.68 3.18 26.85 structure 0.125~0.25 35.05 7.92 42.97 0.062~0.125 44.81 15.89 60.69 0.03~0.062 48.15 21.91 70.06 0.01~0.03 49.11 24.02 73.13 0.01~0.001 49.35 25.87 75.22 750 With the 0.5~1.sup. 15.21 0.00 15.21 guiding 0.25~0.5 40.41 3.92 44.33 structure 0.125~0.25 52.23 10.79 63.02 0.062~0.125 60.60 19.51 80.11 0.03~0.062 64.12 23.04 87.16 0.01~0.03 63.25 24.06 87.31 0.01~0.001 60.34 24.84 85.19 350 With the 0.5~1.sup. 0 guiding 0.25~0.5 1.47 0.02 1.50 structure 0.125~0.25 7.37 5.65 13.02 0.062~0.125 12.30 18.93 31.23 0.03~0.062 16.61 31.34 47.95 0.01~0.03 18.92 39.01 57.93 0.01~0.001 20.70 45.52 66.22 With no 0.5~1.sup. 0.00 guiding 0.25~0.5 7.27 2.60 9.87 structure 0.125~0.25 7.54 11.49 19.03 0.062~0.125 11.51 30.36 41.87 0.03~0.062 13.88 44.96 58.84 0.01~0.03 14.87 50.73 65.60 0.01~0.001 15.90 55.37 71.26 With no 0.5~1.sup. 0.00 2.61 2.61 guiding 0.25~0.5 39.93 10.10 50.03 structure 0.125~0.25 63.47 17.09 80.56 0.062~0.125 57.20 21.15 78.35 0.03~0.062 56.34 22.15 78.49 0.01~0.03 56.76 22.55 79.31 0.01~0.001 58.48 23.19 81.67 1050 With the 0.5~1.sup. 0.00 guiding 0.25~0.5 13.44 2.30 15.74 structure 0.125~0.25 37.40 9.08 46.49 0.062~0.125 57.19 14.79 71.99 0.03~0.062 74.20 18.85 93.05 0.01~0.03 85.82 20.56 106.37 0.01~0.001 74.82 18.11 92.93 With no 0.5~1.sup. 0.00 guiding 0.25~0.5 66.29 4.47 70.76 structure 0.125~0.25 63.92 11.12 75.04 0.062~0.125 63.10 17.00 80.10 0.03~0.062 62.65 18.89 81.54 0.01~0.03 62.23 18.33 80.56 0.01~0.001 61.72 19.77 81.49

[0054] Working principles: the lateral water stopper plates 6 and the top water stopper plate 7 are configured to prevent water from entering the sediment bypass tunnel main body 1 from a top portion and sides of the first regulator 9; by measuring the water height and the sediment concentrations with the monitor system in the controller 12, and sending signals to the drive system by the controller, the drive device can control the first valve lever 11 to rotate, so as to adjust openness of the first regulator 9 autonomously according to water flows and sediment concentrations, by guiding the bottom water flows with higher sediment concentrations from the reservoir to the first regulator 9 then to the weir 8, the weir 8 guides the water flow from the bottom portion of the second regulator 2 to enter the sediment bypass tunnel main body 1 against the stream, and by driving the second braking rim 5 to make vertical movements, the weir 8 can be opened or closed.

[0055] The 1 sediment bypass tunnel; 2 second regulator; 3 second revolution wheel; 4 second valve lever; 5 second braking rim; 6 lateral water stopper plate; 7 top water stopper plate; 8 weir; 9 first regulator; 10 first braking rim; 11 first valve lever and 12 controller are standard parts or parts that those skilled in the art know, and the structures and principles thereof can be obtained from technical books or conventional experiment methods.

[0056] In the foregoing paragraphs the basic principles, primary characteristics and advantages of the present invention are set forth and described, for those skilled in the art, apparently, the present invention is not limited to the details disclosed in the exemplary embodiment, and without departing from the spirit and basic features of the present invention, the present invention can be carried out in other specific forms. Therefore, no matter viewing from any point, the embodiments shall be construed as exemplary and non-restrictive, the scope of the present invention is defined by the appended claims rather than the foregoing description; therefore, all changes that are covered by meanings and ranges of equivalent parts of the claims are covered in the present invention. The drawing marks appeared in the claims shall not be understood to limit the corresponding claims.

[0057] Furthermore, it shall be understood that, although the present invention are described as per embodiments, no every embodiment comprises only a single technical solution, the narration of the description is only for the sake of clarity, those skill in the art shall take the description as an entirety, the technical solutions in the embodiments can be appropriately combined to form other embodiments that those skilled in the art can understand.