Method and system for evaluating fishway of hydropower dam

Abstract

A kind of method and system for evaluating fishway of hydropower dam, via the inclined lower part of suitable vertical slot fishway, a liquid level rising liquid level surface that meets constant flow is generated in vertical slot fishway, the running speed of liquid flow is reduced, and the probability of bubble damage is reduced;Then the control elements suitable for preventing bubble damage and the control specifications prepared during low smoothness are established, to ensure the reliable operation of vertical slot fishway, and also, the bubble damage probability evaluation elements of large-span vertical slot fishway are established to perform accurate measurement.

Description

TECHNICAL FIELD

[0001] The fishway evaluation technology field, in particular to a hydropower dam fishway evaluation method and system. BACKGROUND

[0002] Damming activities in rivers for flood control, power generation, water supply, and navigation have brought a series of negative impacts on aquatic ecosystems, including profound negative effects on fish natural populations. The water retaining structures such as weirs and dams directly change the hydrological conditions of the upstream and downstream, interrupt the continuity of river habitats, block the free migration of fish (not only related to large-scale migratory species, but also to all fish that rely on vertical movement at a certain stage of their life history), and change the long-term adaptive habitats and the environment of river continuity and unobstructedness required by aquatic biodiversity. Fishways are of great significance in mitigating the blocking effects of dams and helping to restore the free migration of fish and other aquatic species in rivers. The effective operation of fishway engineering measures is one of the important technical means to maintain the longitudinal connectivity of rivers.

[0003] The fishway that is currently widely used is the vertical slot fishway, which is usually a cement passage connected to the upstream and downstream of the dam body with a cement or wooden partition plate, suitable for variable upstream water levels of river channels; compared with traditional fishway design, it is not easy to block; this type of fishway is not only suitable for small river channels, but also for large river basins.

[0004] Bubble damage is a common hidden danger of vertical slot fishways under the conditions of river or stream turbulence. Bubble damage is the damage caused by the explosion of bubbles generated in the liquid flow of rivers or streams to vertical slot fishways. According to the research on the damage events of vertical slot fishway structures in different places, the key factors that induce bubble damage include: defects in the structure of vertical slot fishways, resulting in too high bubble quantity in some important areas; displacement and protrusions formed by inaccurate construction, making the liquid flow area not smooth; defects in the operation mode or performing operation without meeting the operation requirements; for vertical slot fishways under the conditions of general river or stream turbulence, using air injection to reduce damage is the most effective method to prevent bubble damage; for vertical slot fishways with small inclination (such as less than 0.075) and liquid flow velocity not less than 24 m / s to 28 m / s (high Froude number), air injection devices cannot easily inject gas, and often produce bubble source hazards due to the inability of the hollow passage of the vertical slot fishway to inject air, resulting in bubble damage; the probability of low smoothness during the construction of large-span vertical slot fishways is not low, and the probability of bubble damage is high; therefore, how to prevent bubble damage in large-span vertical slot fishways that cannot use air injection to reduce damage has become a difficult problem to be solved. SUMMARY

[0005] To solve the problems in the prior art, the present application provides a method and system for evaluating a fishway of a dam of a hydropower station, which generates a liquid level surface with a constant flow by constructing a slanted lower part of a suitable vertical slot fishway, reduces the running speed of the liquid flow, and reduces the probability of bubble damage; then, suitable control elements for preventing bubble damage and control specifications with low smoothness during preparation are established to ensure reliable operation of the vertical slot fishway, and a large-span vertical slot fishway bubble damage probability evaluation element is established to perform accurate measurement.

[0006] The present application uses the following technical solutions.

[0007] A method for evaluating a fishway of a dam of a hydropower station, comprising:

[0008] A group construction mode composed of a slanted lower part 3 of a large-span vertical slot fishway, control elements for preventing bubble damage, and control specifications with low smoothness 4 during preparation;

[0009] The slanted lower part 3 of the large-span vertical slot fishway comprises:

[0010] SA-1, identifying important elements acting on the slanted lower part 3 of the vertical slot fishway and the use interval;

[0011] SA-2, identifying the liquid flow edge requirement: F1 is not higher than the liquid surface height O of the midpoint of the vertical slot fishway, and O is lower than the liquid surface height threshold F m ;

[0012] SA-3, establishing the correlation between the inclination X of the slanted lower part 3 of the vertical slot fishway and the corresponding liquid surface height increment {F0 ÷ F1}, liquid flow bubble factor Y, {F0 ÷ F1} = W(X) and Y = W(X);

[0013] SA-4, establishing the control setting values Y1 and Y2 of the liquid flow bubble factor Y and the corresponding liquid surface height increment {F0 ÷ F1};

[0014] SA-5, performing liquid flow action operation;

[0015] SA-6, identifying the planned slanted lower part 3.

[0016] Preferably, the important elements include the volume E of the liquid flow through a one-meter-wide interval of the vertical slot fishway within a set time length, the vertical height F of the input end of the vertical slot fishway, the lateral span D of the vertical slot fishway, and the distance C between the top points of the input end and the output end of the vertical slot fishway;

[0017] The use interval includes: A = C ÷ D, the value of A is less than 2 / 25, and the running speed U1 of the liquid flow at the input end of the vertical slot fishway is higher than 46 m / s, which is shown in equation (1):

[0018] U1 = J x sqrt{2 x 9.8 x {F - F1}} (1)

[0019] Here, F is the vertical height of the vertical slot fishway input end, J is the flow velocity factor, U1 and F1 are the flow velocity and the liquid level height of the cross section of the input end respectively, F1 = E ÷ U1, E is the volume of the flow of one meter wide interval in the set time period of the vertical slot fishway.

[0020] Preferably, the liquid level height threshold value F m According to equation (2):

[0021] F m = POWER{E 2 ÷ 9.8} (2)

[0022] Here, POWER{} is the cube root of the value in the braces.

[0023] Preferably, the operating equation of the slope of the slope lower part 3 according to the constant flow operation is shown in equation (3):

[0024]

[0025] The flow bubble factor operating equation is shown in equation (4):

[0026] Y = {O + F5 - F6} ÷ {U 2 ÷ 2 x 9.8} (4)

[0027] Here, X is the slope of the slope lower part 3 of the vertical slot fishway, L is the roughness of the slope lower part of the vertical slot fishway, F0 is the constant liquid level height of the constant flow part 33, K is the ratio of the area of the cross section of the vertical slot fishway to the circumference of the cross section; Y is the flow bubble factor, O is the liquid level height of the midpoint of the vertical slot fishway, F5 is the liquid column height with the pressure equivalent to 760 mm of mercury column pressure, F6 is the liquid column height with the pressure equivalent to the flow gasification pressure, U is the average value of the flow velocity of the cross section of the vertical slot fishway;

[0028] Transform equation (3) into equation (5):

[0029] X = {U 2 x L 2} ÷ POWER{K 4} (5)

[0030] Put equation (5) into equation (4) to establish the correlation between the slope X of the slope lower part 3 of the vertical slot fishway and the flow bubble factor Y is equation (6):

[0031] Y = W(X) = {2 x 9.8 x L 2} x {0 + F5 - F6} ÷ {X x POWER{K 4} (6)

[0032] The equation (3) is derived by analysis: the correlation between the inclination X of the inclined lower portion 3 and the corresponding liquid level increment {F0 ÷ F1} is shown in equation (7):

[0033] {F0 ÷ F1} = W(X) = {9.8 x L} ÷ {F1 x sqrt{X} x POWER{K 2} (7).

[0034] Preferably, the SA-4 specifically comprises: establishing the control setting values Y1 and Y2 of the liquid flow bubble factor Y and the corresponding liquid level increment {F0 ÷ F1}, which shall comply with equations (8) and (9) shown:

[0035] Y = W(X) > Y1 (8)

[0036] {F0 ÷ F1} = W(X) < Y2 (9)

[0037] Here, Y1 is the control setting value of the liquid flow bubble factor set in advance; Y2 is the control setting value of the corresponding liquid level increment.

[0038] Preferably, the SA-5 specifically comprises: forming a coordinate graph of the equation {F0 ÷ F1} = W(X) and Y = W(X) calculated in the SA-3, and obtaining the inclination X of the inclined lower portion corresponding to the control setting value Y1 of the liquid flow bubble factor and the control setting value Y2 of the corresponding liquid level increment required in the SA-4 Y and the inclination X O .

[0039] Preferably, the SA-6 specifically comprises: planning the inclination X of the inclined lower portion 3 to comply with X Y and X O , and selecting within the range to obtain the planned inclined lower portion 3 that meets the anti-bubble damage requirement.

[0040] Preferably, the establishment of the control elements for preventing bubble damage and the low-finish 4 control specification during preparation, comprises:

[0041] SB-1, performing a pitting experiment to determine the initial bubble factor of various low-finishes 4 during preparation;

[0042] SB-2, establishing the correlation between the initial bubble factor and the running speed of the liquid flow, and using the equation to simulate the initial bubble factor Y of various low-finishes obtained in SB-1 10and the coordinate diagram of the running velocity U of the liquid flow, as shown in equation (10):

[0043] Y 10 = 0.066U - 0.902 (1 ÷ f) (f-1) (10)

[0044] Here, f is the vertical span of the low finish of the simulation structure; the formula application range: U = 38 m / s to 46 m / s, f = 2 mm to 4 mm;

[0045] SB-3, establishing the control element of preventing bubble damage, selecting the initial bubble factor of the vertical span f = 2 mm of the low finish of the simulation structure in the simulation equation (10) in SB-2 as the control setting value Y1 of the bubble factor of the liquid flow to prevent bubble damage, and the control setting value Y1 of the bubble factor of the liquid flow is associated with the change of the running velocity of the liquid flow as shown in equation (11);

[0046] Y1 = 0.066U - 0.902 (11)

[0047] SB-4, identifying the conversion relationship between the actual vertical span f2 of the low finish 4 and the vertical span f of the low finish of the simulation structure, and calculating the conversion relationship between the actual vertical span f2 and the vertical span f of the low finish of the simulation structure according to the Reynolds number principle as shown in equation (12);

[0048] {f2 ÷ f} = r 0.8 (12);

[0049] SB-5, establishing the low finish 4 control specification during preparation.

[0050] Preferably, the SB-1 specifically comprises: classifying the low finish 4 generated during preparation into several categories, the categories comprising: rod-shaped protrusions, table-shaped protrusions, table-shaped openings, rectangular openings and grooves, the vertical span of each category being 2 mm to 4 mm, performing the pitting experiment under different running velocities of the liquid flow, obtaining the initial bubble factor Y 10 with the mapping relationship of the running velocity U of the liquid flow, and forming a coordinate diagram;

[0051] introducing the preparation stability factor I1, and establishing the low finish 4 control specification Z during preparation that is suitable for the control element of preventing bubble damage: Z is not higher than {f2 ÷ I1};

[0052] If the preparation stability factor I1 is 8.0, the low finish 4 control specification during preparation of the control element of preventing bubble damage σ0 in SB-3 is that Z is not higher than 5.71 mm; the low finish 4 during preparation that is higher than the specification is polished to an inclination of 0.03 to 0.05.

[0053] Preferably, the vertical slot fishway bubble damage probability stability evaluation method comprises:

[0054] The probability evaluation factor I is used as the vertical slot fishway bubble damage resistance probability stability evaluation element, I = I1 * I2, wherein:

[0055] I1 is a preparation stability probability factor, I1 = 2 * Z ÷ a, a is the actual preparation period low-smoothness 4, when a is not higher than Z, I1 is higher than two;

[0056] I2 is a construction probability stability factor, when the input end liquid flow running speed U1 is lower than 38 m / s, or the input end liquid flow running speed U1 is higher than 38 m / s, the liquid level surface 2 of the liquid level rising part 32 connected with the constant flow part 33 in the vertical slot fishway is generated through the planned inclined lower part 3, the liquid flow running speed U0 is reduced to be lower than 38 m / s, I2 = 3 / 2; the liquid flow running speed is reduced to U0 higher than 38 m / s and lower than 40 m / s, I2 is one; the liquid flow running speed is reduced to U0 higher than 40 m / s, I2 = 3 / 4.

[0057] A hydropower station dam fishway evaluation system comprises:

[0058] A processor and a storage medium; characterized in that:

[0059] The storage medium is used for storing instructions;

[0060] The processor is used for operating according to the instructions to execute the steps of the hydropower station dam fishway evaluation method.

[0061] The beneficial effects of the present application are that, compared with the prior art, the present application reduces the liquid flow running speed through the inclined lower part construction method of generating the liquid level surface of the liquid level rising part connected with the constant flow part, improves the stability of resisting bubble damage, and accurately gives the bubble damage prevention control element and the preparation period low-smoothness control specification according to the large-span liquid flow performance division and the bubble characteristics of the preparation period low-smoothness. The present application gives a precise measurement method for evaluating the bubble damage resistance probability of the large-span vertical slot fishway. The present application achieves the optimal bubble damage resistance performance, preparation convenience, strong stability, low cost, and precise measurement method for evaluating the bubble damage probability of the large-span vertical slot fishway by using the most convenient architecture and construction method. BRIEF DESCRIPTION OF DRAWINGS

[0062] Figure 1 is a structure diagram of the liquid flow generating a liquid level surface of a liquid level rising part connected with a constant flow part in the vertical slot fishway in the present application;

[0063] Figure 2It is a coordinate graph formed by the equations {F0÷F1}=W(X) and Y=W(X) described in this invention;

[0064] Figure 3 The initial bubble factor Y is obtained as described in this invention. 10 A coordinate graph formed by mapping and relating the fluid flow velocity U;

[0065] Figure 4 This is a flowchart of SA-1 to SA-6 in this invention;

[0066] Figure 5 This is a flowchart of SB-1 to SB-5 in this invention. Detailed Implementation

[0067] The meanings of some technical terms in this invention are as follows:

[0068] The present application will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention, and should not be construed as limiting the scope of protection of the present application.

[0069] The present invention provides a method for evaluating fishway systems in hydropower station dams, such as... Figure 1 As shown, it includes:

[0070] The inclined lower part of the large-span vertical slot fishway is constructed by 3 components, and the control elements that prevent bubble damage are established and the low surface finish is established during the preparation process. 4 Control specifications constitute the group construction mode; the vertical slot fishway is a cement channel with cement or wooden planks connecting the upstream and downstream of the dam body.

[0071] like Figure 4 As shown, the inclined lower section 3 of the large-span vertical slotted fishway comprises:

[0072] SA-1 identifies the key elements and application range of the inclined lower part 3 that act on the vertical slotted fishway.

[0073] In a preferred but non-limiting embodiment of the present invention, the key elements include the volume E of liquid flowing through a one-meter-wide section of the vertical slit fishway within a set time period, the vertical height F of the input end of the vertical slit fishway, the lateral span D of the vertical slit fishway, and the distance C between the vertices of the input and output ends of the vertical slit fishway; the volume E of liquid flowing through a one-meter-wide section of the vertical slit fishway within a set time period is the volume of liquid flowing through a one-meter-wide section of the cross-section of the vertical slit fishway within the set time period, and the set time period can be one second.

[0074] The application range includes: A = C ÷ D, the value of A is less than 2 / 25, the running speed U1 of the liquid flow at the input end of the vertical slit fishway should not exceed 46 m / s, and its equation is shown in equation (1):

[0075] U1 = J x sqrt{2 x 9.8 x {F - F1}} (1)

[0076] The application uses the running speed U1 of the liquid flow at the input end of the vertical slot fishway, which is not higher than 46 m / s, and sqrt{} is the square root of the value in the braces. If the running speed of the liquid flow is higher than 46 m / s, the height of the input end should be changed or a device for reducing the damage of air injection should be developed and researched.

[0077] Here, F is the vertical height of the input end of the vertical slot fishway, J is the running speed factor of the liquid flow (the running speed factor is usually 0.82), U1 and F1 are the running speed and the liquid level height of the cross section of the input end of the liquid flow, respectively, F1 = E ÷ U1, and E is the volume of the liquid flow per meter wide interval in a set time interval for constructing the vertical slot fishway.

[0078] SA-2, the liquid flow edge requirement is that F1 is not higher than the liquid level height O at the midpoint of the vertical slot fishway and O is lower than the liquid level height threshold F m ;

[0079] The running speed of the liquid flow in the vertical slot fishway is reduced by selecting an appropriate inclination of the inclined lower portion 3 to generate a liquid level rising portion 32 and a constant flow portion 33 of the liquid level surface 2 of the liquid flow in the vertical slot fishway; the liquid flow edge requirement to be met is that F1 is not higher than O and O is lower than F m , that is, the liquid level height O at the midpoint of the vertical slot fishway is not lower than the liquid level height F1 of the cross section of the input end, and is lower than the liquid level height threshold F m , to prevent the occurrence of a condition in which the running speed of the liquid flow in the vertical slot fishway is reduced and acts on the liquid discharge or causes the liquid level to be significantly high; here, O = F1 is considered as a special case, which is the condition of the constant flow portion 33 in which the running speed of the liquid flow at the input end is maintained constant.

[0080] In the preferred but non-limiting embodiment of the application, the liquid level height threshold F m is obtained according to equation (2):

[0081] F m = POWER{E 2 ÷ 9.8} (2)

[0082] Here, POWER{} is the cubic root of the value in the braces.

[0083] SA-3, the inclination X of the inclined lower portion 3 of the vertical slot fishway is associated with the corresponding liquid level height increment {F0 ÷ F1} and the liquid flow bubble factor Y, {F0 ÷ F1} = W(X) and Y = W(X);

[0084] In a preferred but non-limiting embodiment of the present application, the equation for calculating the slope X of the sloped lower portion 3 according to the constant flow calculation is shown in equation (3):

[0085] X = {E 2 × L 2} ÷ {F0 2 × POWER{K 4}} (3)

[0086] The equation for calculating the liquid flow bubble factor Y is shown in equation (4):

[0087] Y = {O + F5 - F6} ÷ {U 2 ÷ 2 × 9.8} (4)

[0088] Here, X is the slope of the sloped lower portion 3 of the vertical slot fishway, L is the roughness of the sloped lower portion of the vertical slot fishway, F0 is the constant liquid level height of the constant flow portion 33, K is the ratio of the cross-sectional area of the vertical slot fishway to the perimeter of the cross-section; Y is the liquid flow bubble factor, O is the liquid level height at the midpoint of the vertical slot fishway, F5 is the liquid column height with a pressure equivalent to 760 mm of mercury pressure, F6 is the liquid column height with a pressure equivalent to the pressure of the liquid flow vaporization, U is the average of the running speed of the liquid flow in the cross-section of the vertical slot fishway; the liquid in the liquid column is the liquid of the liquid flow.

[0089] Equation (3) is transformed into equation (5):

[0090] X = {U 2 × L 2} ÷ POWER{K 4} (5)

[0091] Equation (5) is substituted into equation (4) to establish the correlation between the slope X of the sloped lower portion 3 of the vertical slot fishway and the liquid flow bubble factor Y as equation (6):

[0092] Y = W(X) = {2 × 9.8 × L 2} × {O + F5 - F6} ÷ {X × POWER{K 4}} (6)

[0093] Equation (3) is analyzed to obtain the correlation between the slope X of the sloped lower portion 3 and the corresponding liquid level height increment {F0 ÷ F1} as equation (7):

[0094] {F0 ÷ F1} = W(X) = {9.8 × L} ÷ {F1 × sqrt{X} × POWER{K 2}} (7)

[0095] SA-4, establish control settings Y1 and Y2 for the liquid flow bubble factor Y and the corresponding liquid surface height increase {F0÷F1};

[0096] In a preferred but non-limiting embodiment of the present invention, the SA-4 specifically includes: establishing control settings Y1 and Y2 for the liquid flow bubble factor Y and the corresponding liquid surface height increase {F0÷F1}, which must conform to equations (8) and (9):

[0097] Y = W(X) > Y1 (8)

[0098] {F0÷F1}=W(X) <Y2 (9)

[0099] Here, Y1 is the preset control setting value for the liquid flow bubble factor; Y2 is the control setting value for the corresponding increase in liquid level height.

[0100] SA-5 performs fluid flow operation calculations;

[0101] In a preferred but non-limiting embodiment of the present invention, the SA-5 specifically includes: as follows Figure 2 As shown, by plotting the equations {F0÷F1}=W(X) and Y=W(X) from SA-3 onto a coordinate graph, the control setting value Y1 for the liquid flow bubble factor required in SA-4 and the corresponding control setting value Y2 for the increase in liquid level height are obtained, defining the inclination X of the lower part of the inclined type. Y With tilt X O The horizontal axis of this coordinate graph is X, and the vertical axis is Y or {F0÷F1}.

[0102] SA-6, designated as the lower part of the inclined plan 3;

[0103] In a preferred but non-limiting embodiment of the present invention, the SA-6 specifically includes: the tilt angle X of the planned tilted lower part 3 must meet the requirement that X is lower than X. Y And X is higher than X O Within this range, a plan for a tilted lower section 3 is selected that meets the requirements for preventing bubble damage and is cost-effective.

[0104] In a preferred but non-limiting embodiment of the invention, such as Figure 5 As shown, the control elements for preventing bubble damage and the low surface finish control specifications during preparation include: the preparation here refers to the preparation of a vertical slit fishway.

[0105] SB-1, performed cavitation experiments to identify the initial bubble factor of low surface finish 4 during various preparation processes;

[0106] In the preferred but non-limiting embodiment of the present application, the SB-1 specifically comprises: the low-finish 4 generated during preparation is classified into several categories, including: rod-shaped protrusions, table-shaped protrusions, table-shaped openings, rectangular openings, and grooves, each category has a vertical span of 2 to 4 mm, and a cavitation experiment is performed at different flow velocities to obtain the initial bubble factor Y 10 with the mapping relationship of the flow velocity U, and a coordinate graph is formed; as shown in Figure 3 , the initial bubble factor Y is obtained here using the rod-shaped protrusions that are most likely to form bubbles 10 The coordinate graph of the initial bubble factor Y (ordinate) with the flow velocity v (abscissa) is shown in

[0107] Currently, manuals provide the initial bubble factors of two categories of low-finish, which can be found according to the ratio of the vertical span of the unevenness and the thickness at the edge, but the thickness at the edge is difficult to determine, and the values in the manual are not simple; most importantly, the initial bubble factor does not exhibit a mapping relationship with the flow velocity.

[0108] SB-2, establishes the relationship between the initial bubble factor and the flow velocity, and uses the equation to simulate the initial bubble factors Y of various low-finishes obtained in SB-1 10 and the flow velocity U, as shown in equation (10):

[0109] Y 10 = 0.066U - 0.902 (1 ÷ f) (f-1) (10)

[0110] Here, f is the vertical span of the low-finish category of the simulated structure; the formula is used in the range of U = 38 to 46 m / s and f = 2 to 4 mm; the simulated structure is a simulation of the actual vertical slot fishway structure.

[0111] SB-3, establishes a control element to prevent bubble damage, and selects the initial bubble factor of the low-finish of the simulated structure with a vertical span f = 2 mm in the simulation equation (10) in SB-2 as the control setting value Y1 of the flow bubble factor to prevent bubble damage, and the control setting value Y1 of the flow bubble factor is related to the change of the flow velocity as shown in equation (11);

[0112] Y1 = 0.066U - 0.902 (11)

[0113] SB-4, determines the conversion relationship between the actual vertical span f2 of the low-finish 4 and the vertical span f of the low-finish of the simulated structure, and calculates the conversion relationship between the actual vertical span f2 and the vertical span f of the low-finish of the simulated structure according to the Reynolds number principle as shown in equation (12);

[0114] {f2÷f}=r 0.8 (12);

[0115] For example, the simulation structure of the hole erosion experiment and the size ratio r of the actual vertical slot fishway are 50, the low smoothness vertical span f of the simulation structure is 2 mm, and the low smoothness vertical span f2 of the actual low smoothness 4 is 45.73 mm.

[0116] SB-5, establishing the low smoothness 4 control specification during preparation;

[0117] Regarding the aggregation performance of the low smoothness 4 probability during preparation, the preparation stability probability factor I1 is introduced, and the low smoothness 4 control specification Z suitable for the preparation during preparation and the control element for preventing bubble damage is established, that is, Z is not higher than {f2÷I1};

[0118] If the preparation stability probability factor I1 is 8.0, the low smoothness 4 control specification of the control element for preventing bubble damage σ0 in SB-3 during preparation is that Z is not higher than 5.71 mm; the low smoothness 4 during preparation higher than the specification is polished to an inclination of 0.03 to 0.05.

[0119] In the preferred but non-limiting embodiment of the present application, facing the above construction method, the present application also provides a large-span vertical slot fishway bubble damage probability stability evaluation method related to the aggregation performance of the low smoothness 4 probability during preparation, which comprises:

[0120] The probability evaluation factor I is used as the vertical slot fishway bubble damage probability stability evaluation element, I=I1×I2, where:

[0121] I1 is the preparation stability probability factor, I1=2×Z÷a, a is the actual low smoothness 4 during preparation, and when a is not higher than Z, then I1 is higher than two;

[0122] I2 is the construction probability stability factor, when the operating speed U1 of the liquid flow at the input end is lower than 38 m / s, or the operating speed U1 of the liquid flow at the input end is higher than 38 m / s, but the liquid level surface 2 of the liquid level rising part 32 connected to the constant flow part 33 in the vertical slot fishway is generated through the planned inclined lower part 3, the operating speed U0 of the liquid flow is reduced to be lower than 38 m / s, I2=3 / 2; the operating speed of the liquid flow is reduced to U0 higher than 38 m / s and lower than 40 m / s, I2 value is one; the operating speed of the liquid flow is reduced to U0 higher than 40 m / s, I2=3 / 4.

[0123] The probability evaluation factor I=I1×I2; when I is higher than two, the bubble damage probability is small, when I is two, the bubble damage probability is not large, but the stability margin of the bubble damage probability is not large, and when I is lower than two, the bubble damage probability is large.

[0124] Via the method, the large-span vertical slot fishway is protected from bubble damage. Via the method of constructing the inclined lower part 3 of the liquid level surface 2 connecting the liquid level rising part 32 to the constant flow part 33, the running speed of the liquid flow is reduced, the stability against bubble damage is improved, the control elements for preventing bubble damage and the control specifications for the low-smoothness 4 during preparation are accurately given according to the large-span liquid flow performance, and the accurate determination method for evaluating the bubble damage probability of the large-span vertical slot fishway is given.

[0125] The following is a further description of the method of the present application by way of example:

[0126] The construction specifications of the vertical slot fishway: the volume of the liquid flow passing through the vertical slot fishway within a set time is 8166 cubic meters per second, the vertical height F of the input end of the vertical slot fishway is 38 meters, the horizontal span D of the vertical slot fishway is 480 meters, the maximum inclination of the vertical slot fishway is less than 5%, and no effective air injection device can be installed. For such a large-span vertical slot fishway section, the inclined lower part 3 of the bubble damage prevention plan, the control specification for the low-smoothness during preparation, and the determination of the bubble damage probability of the large-span vertical slot fishway are determined.

[0127] The width of the cross section of the input end of the vertical slot fishway is 28 meters, and the liquid surface height is 19 meters. The volume of the liquid flow passing through a one-meter-wide interval E is 291.6 cubic meters per second.

[0128] The running speed U1 of the liquid flow at the input end of the vertical slot fishway is calculated according to equation (1), the liquid flow running speed factor J is 0.82, the liquid surface height F1 of the liquid flow at the cross section of the input end is 19 meters, and the running speed U1 of the liquid flow at the input end is J x sqrt{2 x 9.8 x {F - F1}} = 15.82 m / s. Thus, the input end is classified as a large-span rising part, and the running speed of the liquid flow is less than 46 m / s. Via the inclined lower part 3 construction method of the present application, the liquid level surface 2 connecting the liquid level rising part 32 to the constant flow part 33 in the vertical slot fishway is constructed, the running speed of the liquid flow at the input end is reduced via the liquid level rising part 32, and then the constant flow part 33 is maintained, thereby reducing the bubble damage probability.

[0129] Determination of the liquid flow edge requirement: the liquid surface height O at the midpoint of the vertical slot fishway should satisfy F1 not higher than O and O lower than F m , the liquid surface height threshold F m = POWER{E 2 ÷ 9.8} = 20.48 meters, so O is higher than 19 meters and lower than 20.48 meters.

[0130] The liquid flow bubble factor is calculated according to equation (4), F5 is the height of liquid column with pressure equivalent to 760 mm of mercury pressure and is 10.66 meters; F6 is the height of liquid column with pressure equivalent to the pressure of liquid flow aeration and is 0.32 meters, and the calculation of the liquid flow bubble factor is:

[0131] Y = {O + F5 - F6} ÷ {U 2 ÷ 2 x 9.8} = {19 + 10.66 - 0.32} ÷ {15.82 2 ÷ 2 x 9.8} = 0.24

[0132] The liquid flow bubble factor Y and the corresponding liquid surface height increment {F0 ÷ F1} of the constant flow part 33 of the inclined lower portion 3 under the inclination X condition are calculated according to equations (6) and (7), and the two equations Y = W(X) and {F0 ÷ F1} = W(X) are formed on a coordinate graph.

[0133] The operating set values Y1 and Y2 of the liquid flow bubble factor Y and the corresponding liquid surface height increment {F0 ÷ F1} are required to meet equations (8) and (9):

[0134] Y = W(X) > Y1 (8)

[0135] {F0 ÷ F1} = W(X) < Y2 (9)

[0136] According to the operating element Y1 = 0.066U - 0.902 for preventing bubble damage, and the operating speed of the liquid flow at the input end is 15.82 meters / second, Y1 = 0.70 is selected, and the corresponding planned operating speed of the liquid flow of the constant flow part 33 of the inclined lower portion 3 is 24.24 meters / second; simultaneously, the overall effect of the increase of the liquid surface height on the fishway preparation is considered, and the corresponding liquid surface height increment operating element Y2 = 1.30 is selected.

[0137] According to the defined specifications of the planned inclined lower portion 3, Y is higher than 0.70 and {F0 ÷ F1} is lower than 1.30, the calculation obtains the inclination X of the inclined lower portion corresponding to Y = 0.70 Y = 0.0169, and the inclination X of the inclined lower portion corresponding to {F0 ÷ F1} = 1.25 O = 0.0098;

[0138] The inclination X of the planned inclined lower portion 3 can be selected within the range of 0.0098 to 0.0169;

[0139] Two examples of the inclined lower portion 3 are compared:

[0140] I. According to the synchronous vertical slit fishway which meets the requirements of preventing bubble damage, the most effortless change is to add the vertical height of the synchronous vertical slit fishway, and the inclination X of the planned inclined lower part 3 is selected as 0.0148, so that the corresponding liquid level increment {F0÷F1} is calculated or obtained from the coordinate graph as 1.052, that is, the liquid level F0 of the corresponding constant flow part 33 of the inclined lower part 3 is only 1.052 times the liquid level h1 of the input end, so that the vertical height of the synchronous vertical slit fishway can be increased, the running speed U0 of the corresponding constant flow part 33 is E÷F0=24.3 m / s, the bubble factor of the cross-section of the constant flow part 33 is 0.786, which is higher than 0.70, and meets the requirements of preventing bubble damage, but the stability margin is low; under the condition that the preparation period low smoothness is lower than the control specification, the bubble damage probability factor I=I1×I2 is 2, the bubble damage probability is small, but the stability margin of the bubble damage probability is not large.

[0141] II. According to the maximum reduction of the bubble damage probability, the inclination X of the planned inclined lower part 3 is selected as 0.0099, so that the corresponding liquid level increment {F0÷F1} is calculated or obtained from the coordinate graph as 1.198, that is, the liquid level F0 of the corresponding constant flow part 33 of the inclined lower part 3 is 1.198 times the liquid level F1 of the input end, the vertical height of the corresponding synchronous vertical slit fishway is increased by 19.8%, the preparation cost of the synchronous vertical slit fishway is increased, but the running speed of the liquid flow can be reduced to U0=E÷F0=21.9 m / s, the corresponding bubble factor is 0.90, which is higher than 0.75, and meets the requirements of preventing bubble damage, and the stability margin is large, the bubble damage probability factor I=I1×I2 is 3, and the bubble damage probability is small.

[0142] The two examples of the inclined lower part 3 can meet the requirements of preventing bubble damage, and finally selected by comparing the preparation difficulty and cost, the probability of the preparation period low smoothness 4 is related to the large-span preparation period low smoothness 4, and the control specification Z of the preparation period low smoothness 4 is not higher than {f2÷I1}, {f2÷I1} 5.71 mm; the preparation period low smoothness 4 which is higher than the specification is polished to an inclination of 0.03 to 0.05.

[0143] A hydropower dam fishway evaluation system, comprising:

[0144] A processor and a storage medium; characterized in that:

[0145] The storage medium is used to store instructions;

[0146] The processor is used to operate according to the instructions to perform the steps of the hydropower dam fishway evaluation method.

[0147] The beneficial effects of the present application are that, compared with the prior art, the present application generates a tilting lower part of the liquid level surface through the manipulation of the liquid flow in the hole, reduces the running speed of the liquid flow, improves the stability against bubble damage, and gives the manipulation elements for preventing bubble damage and the manipulation specifications for the low-smoothness bubbles during preparation according to the performance of the large-span liquid flow, and gives a precise measurement method for evaluating the probability of bubble damage of the large-span vertical slit fishway. The present application achieves the optimal bubble damage resistance performance, preparation convenience, strong stability, low cost, and precise measurement method for evaluating the probability of bubble damage of the large-span vertical slit fishway with the most convenient architecture and construction method.

[0148] The applicant of the present application has made a detailed description and explanation of the embodiments of the present application in combination with the drawings of the specification, but those skilled in the art should understand that the above embodiments are only preferred embodiments of the present application, and the detailed description is only to help the reader better understand the spirit of the present application, and is not a limitation on the protection scope of the present application. On the contrary, any improvement or modification based on the spirit of the present application should fall within the protection scope of the present application.

Claims

1. A method for evaluating a fishway of a hydropower dam, characterized in that, Comprise: The inclined lower part 3 of the large-span vertical slot fishway is constructed, and a set of construction modes is established, which comprises the control elements for preventing bubble damage and the low-finish control specifications during preparation; The inclined lower part 3 of the large-span vertical slot fishway is constructed, and a set of construction modes is established, which comprises the control elements for preventing bubble damage and the low-finish control specifications during preparation; SA-1, identifying the important elements acting on the inclined lower part 3 of the vertical slot fishway and the application range; SA-2, the liquid flow edge requirement is identified: F1 is not higher than the midpoint of the vertical slit fishway liquid level O and O is lower than the liquid level threshold F m ; SA-3, establishing the correlation between the inclination X of the inclined lower part of the vertical slot fishway and the corresponding liquid surface height increment {F0 ÷ F1}, the flow bubble factor Y, {F0 ÷ F1} = W(X) and Y = W(X); SA-4, establishing the control set values Y1 and Y2 of the flow bubble factor Y and the corresponding liquid surface height increment {F0 ÷ F1}; SA-5, performing flow action operation; SA-6, identifying the planned inclined lower part; The control elements for preventing bubble damage and the low-finish control specifications during preparation, comprise: SB-1, performing pitting corrosion experiment, identifying the initial bubble factor of various low-finishes during preparation; SB-2, which establishes the correlation between the starting bubble factor and the flow rate of the liquid stream, uses an equation to simulate the various low-finish starting bubble factors Y achieved in SB-1 10 and the flow rate of the liquid stream U, as shown in equation (10): Y 10 = 0.066U - 0.902(1 ÷ f) (f-1) (10) Here, f is the vertical span of the low-finish of the simulation structure; the formula application range: U = 38-46 m / s, f = 2-4 mm; SB-3, establishing the control elements for preventing bubble damage, selecting the initial bubble factor of the vertical span f = 2 mm of the low-finish of the simulation structure in the simulation equation (10) in SB-2 as the control set value Y1 of the flow bubble factor for preventing bubble damage, and the control set value Y1 of the flow bubble factor is associated with the change of the running speed of the flow as shown in equation (11); Y1 = 0.066U - 0.902 (11) SB-4, identifying the conversion relationship between the actual vertical span f2 of the low-finish and the vertical span f of the low-finish of the simulation structure, and calculating the conversion relationship between the actual vertical span f2 and the vertical span f of the low-finish of the simulation structure according to the Reynolds number principle as shown in equation (12); {f2÷f} = r 0.8 (12); SB-5, establishing the low-finish 4 control specifications during preparation.

2. The method of claim 1, wherein, The important elements comprise the volume E of the flow passing through a one-meter-wide interval of the vertical slot fishway within a set time, the vertical height F of the input end of the vertical slot fishway, the lateral span D of the vertical slot fishway, and the distance C between the two vertices of the input end and the output end of the vertical slot fishway; The application range comprises: A = C ÷ D, the value of A is less than 2 / 25, and the running speed U1 of the flow at the input end of the vertical slot fishway is higher than 46 m / s, and the equation is as shown in equation (1): U1 = J × sqrt{2 × 9.8 × {F - F1}} (1) Here, F is the vertical height of the input end of the vertical slot fishway, J is the running speed factor of the flow, U1 and F1 are respectively the running speed and the liquid surface height of the flow at the cross section of the input end, F1 = E ÷ U1, and E is the volume of the flow passing through a one-meter-wide interval of the vertical slot fishway within a set time.

3. The method of claim 1, wherein the method further comprises: The liquid level threshold F m According to equation (2): F m = POWER{E 2 ÷9.8} (2) Here, POWER{} is the cube root of the value in the braces.

4. The method of claim 1, wherein, The calculation equation of the inclination X of the inclined lower part according to the constant flow calculation is as shown in equation (3): The flow bubble factor calculation equation is as shown in equation (4): Y = {0 + F5 - F6} ÷ {U 2 ÷ 2 x 9.8} (4) Here, X is the inclination of the inclined lower portion of the vertical slot fishway, L is the smoothness of the inclined lower portion of the vertical slot fishway, F0 is the constant liquid level of the constant flow portion, K is the ratio of the area of the cross section of the vertical slot fishway to the perimeter of the cross section; Y is the liquid flow bubble factor, O is the liquid level at the midpoint of the vertical slot fishway, F5 is the height of the liquid column with a pressure equivalent to 760 mm of mercury pressure, F6 is the height of the liquid column with a pressure equivalent to the pressure of the liquid flow gasification, and U is the average value of the flow velocity of the liquid flow in the cross section of the vertical slot fishway. Equation (3) is transformed into equation (5): X = {U 2 X L 2} ÷ POWER {K 4} (5) Equation (5) is input into equation (4) to establish the correlation between the inclination X of the inclined lower portion of the vertical slot fishway and the liquid flow bubble factor Y, which is equation (6): Y = W(X) = {2 x 9.8 x L 2} x {0 + F5 - F6} ÷ {X x POWER{K 4}} (6) Through analysis of equation (3), the correlation between the inclination X of the inclined lower portion and the corresponding liquid level increase {F0 ÷ F1} is shown in equation (7): {F0 ÷ F1} = W(X) = {9.8 x L} ÷ {F1 x sqrt{X} x POWER{K 2}} (7).

5. The method of claim 1, wherein the method further comprises: The SA-4 specifically includes establishing the control set values Y1 and Y2 of the liquid flow bubble factor Y and the corresponding liquid level increase {F0 ÷ F1}, which should meet equations (8) and (9): Y = W(X) > Y1 (8) {F0 ÷ F1} = W(X) < Y2 (9) Here, Y1 is the control set value of the liquid flow bubble factor set in advance, and Y2 is the control set value of the corresponding liquid level increase.

6. The method of claim 1, wherein, The SA-5 specifically includes: forming a coordinate graph of the equation {F0 ÷ F1} = W(X) operated in the SA-3 and Y = W(X), obtaining the inclination X of the defined inclined lower part corresponding to the operation setting value Y1 of the liquid flow bubble factor and the operation setting value Y2 of the corresponding liquid surface height increment in the SA-4 Y corresponding to the inclination X O .

7. The method of claim 1, wherein the method further comprises: The SA-6 specifically includes that the inclination X of the planned inclined lower portion should be in the range of X Y and X O , and is selected within the range to obtain a planned inclined lower portion that meets the anti-bubble damage requirement.

8. The method of claim 7, wherein the fishway evaluation method is a fishway evaluation method for a hydroelectric dam fishway. The SB-1 specifically includes: the low finish generated during preparation is summarized into several categories, the categories include: rod-shaped protrusions, table-shaped protrusions, table-shaped openings, rectangular openings and grooves, the vertical span of each category is 2-4 mm, the cavitation experiments are performed under different flow running speeds of different liquid flows, and the initial bubble factor Y is obtained 10 With the mapping correlation of the flow running speed U, and a coordinate diagram is formed; The preparation stability factor I1 is introduced to establish the preparation period low smoothness control specification Z that is adapted to the control elements that prevent bubble damage, which is that Z is not higher than {f2 ÷ I1}; If the preparation stability factor I1 is 8.0, the preparation period low smoothness control specification of the control element σ0 that prevents bubble damage in SB-3 is that Z is not higher than 5.71 mm; the preparation period low smoothness that is higher than the specification is polished to a smoothness of 0.03 to 0.05; The vertical slot fishway bubble damage probability stability evaluation method includes: The probability evaluation factor I is used as the vertical slot fishway bubble damage resistance probability stability evaluation element, I = I1 × I2, where: I1 is the preparation stability factor, I1 = 2 × Z ÷ a, a is the actual preparation period low smoothness, and when a is not higher than Z, then I1 is higher than two; I2 is the probability stability factor, when the input flow velocity U1 is lower than 38 m / s, or the input flow velocity U1 is higher than 38 m / s, the liquid level surface 2 of the liquid level rise portion connected to the constant flow portion is generated in the vertical slot fishway through the planned inclined lower portion, the flow velocity U0 is reduced to be lower than 38 m / s, I2 = 3 / 2; the flow velocity is reduced to U0 higher than 38 m / s and lower than 40 m / s, I2 is one; the flow velocity is reduced to U0 higher than 40 m / s, I2 = 3 / 4.

9. A hydropower station dam fishway evaluation system, comprising: a processor and a storage medium; characterized in that: the storage medium is used to store instructions; the processor is used to operate according to the instructions to perform the steps of the hydropower station dam fishway evaluation method according to any one of claims 1-8.

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