Design method of vertical shaft type water inlet and outlet structure and vertical shaft type water inlet and outlet structure

Abstract

The invention discloses a vertical shaft type water inlet and outlet structure design method and a vertical shaft type water inlet and outlet structure, and relates to the technical field of water conservancy and hydropower engineering.The vertical shaft type water inlet and outlet structure design method comprises the steps that firstly, according to actual engineering operation conditions, initial body shape design of the vertical shaft type water inlet and outlet structure is carried out, and basic design parameters of the initial body shape of the vertical shaft type water inlet and outlet structure are obtained; 2, determining the starting end section diameter of the turning section and the tail end section diameter of the turning section; 3, the turning radius, the turning inner diameter and the turning outer diameter of the turning section are calculated, and the length of the connecting diffusion section is calculated; and 4, based on the turning radius of the turning section, the turning inner diameter of the turning section, the turning outer diameter of the turning section, the turning angle of the turning section, the length of the connection diffusion section and the diffusion angle of the connection diffusion section, verification is carried out in three-dimensional design software. According to the invention, the problem of non-uniform flow distribution of each flow channel caused by the bias flow influence of the turning section is solved, and the safe and stable operation of hydraulic and hydroelectric engineering is ensured.

Description

Technical Field

[0001] The invention relates to the technical field of water conservancy and hydropower engineering, and in particular to a design method for a vertical shaft type water inlet and outlet structure and the vertical shaft type water inlet and outlet structure. Background Art

[0002] As the basic building in the pumped storage power station, the shaft-type inlet and outlet structure is the key part to realize the water flow control and water energy utilization of the power station. The quality of its hydraulic characteristics will have a direct impact on the safe and efficient operation of the power station. Under the outflow condition, due to the existence of the turning section, the centrifugal force of the water flow in the turning section causes uneven flow distribution in each flow channel, resulting in a biased flow problem on the plane. Summary of the invention

[0003] The purpose of the present invention is to provide a design method and a shaft-type water inlet and outlet structure to solve the problem of uneven flow distribution in each flow channel caused by the influence of biased flow in the turning section, so as to ensure the safe and stable operation of hydraulic and hydropower projects.

[0004] To achieve the above object, the present invention provides the following solutions:

[0005] The present invention provides a design method for a vertical shaft type water inlet and outlet structure, comprising the following steps:

[0006] Step 1: According to the actual project operation conditions, the initial shape design of the shaft-type water inlet and outlet structure is carried out, and the basic design parameters of the initial shape of the shaft-type water inlet and outlet structure are as follows: the diameter of the pressurized pipe section is d1, and the diameter of the starting end section connecting the diffusion section is d k1 The diameter of the end section connecting the diffuser is d k2 , the diameter of the vertical pipe section is d2;

[0007] Step 2: Determine the cross-sectional diameter d of the starting end of the turning section z1 and the end section diameter d of the turning section z2 , d z1 =d k2 , d z2 =d2;

[0008] Step 3: Calculate the turning radius R of the turning section m , the inner radius R of the turning section in , the turning outer diameter R of the turning section ex , calculate the length L of the connecting diffusion section;

[0009] Step 4: Turning radius R based on the turning section m , the inner radius R of the turning section in , the turning outer diameter R of the turning section ex, the turning angle θ of the turning section, the length L of the connecting diffuser section and the diffusion angle of the connecting diffuser section Verify in 3D design software.

[0010] Preferably, the turning radius R of the turning section is m The formula is as follows:

[0011] R m =α·d1

[0012] Among them, α is the turning radius coefficient, and its value range is 2.1 to 2.2.

[0013] Preferably, the inner radius R of the turning section is in The formula is as follows:

[0014] R in =β·d1

[0015] Wherein, β is the inner diameter coefficient of the turn, β = 0.8871·α.

[0016] Preferably, the turning outer diameter R of the turning section is ex The formula is as follows:

[0017] R ex =γ·d1

[0018] Wherein, γ is the turning outer diameter coefficient, γ = 1.1987·α.

[0019] Preferably, the turning angle θ of the turning section is 90°.

[0020] Preferably, the length L of the connecting diffusion section is calculated as follows:

[0021]

[0022] Preferably, the diffusion angle of the connecting diffuser is The value range is

[0023] The present invention also provides a vertical shaft type water inlet and outlet structure obtained by adopting the design method of the vertical shaft type water inlet and outlet structure, comprising a pressurized pipe section, a connecting diffusion section, a turning section, a vertical pipe section, a bell mouth section and a trash rack section connected in sequence, and the trash rack section is provided with a flow channel evenly distributed along the circumference of the trash rack section.

[0024] Preferably, the center line of the connecting diffuser section is arranged perpendicular to the center line of the vertical pipe section.

[0025] Compared with the prior art, the present invention has achieved the following technical effects:

[0026] The present invention clarifies the design method of the turning section in the shaft type water inlet and outlet structure through the turning radius coefficient, the turning inner diameter coefficient and the turning outer diameter coefficient; in addition, the diffusion angle of the connecting diffusion section is introduced to adapt to the diversion requirements under different operating flow rates.

[0027] Compared with the conventional body-shaped flow section shrinking along the way, the vertical shaft type water inlet and outlet structure obtained by the design method of the vertical shaft type water inlet and outlet structure of the present invention has a flow section that first expands and then shrinks along the way in the turning section, and the water flow path is shorter (such as Figure 2 As shown in the figure, it accelerates the mixing and homogenization of water flow inside the turning section, so that the water flow velocity entering the vertical pipe section is evenly distributed in the lateral direction, effectively solving the adverse effects caused by the bend flow deviation effect, saving the workload of designers, improving the optimization efficiency, and ensuring the safe and stable operation of the project. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 A vertical shaft type water inlet and outlet structure (having a pressure pipe section, a connecting diffusion section, a turning section and a vertical pipe section) obtained by adopting the design method of the vertical shaft type water inlet and outlet structure of the present invention;

[0030] Figure 2 A comparison diagram of the changes in the pipe diameter of the flow section of the turning section of the present invention and the conventional turning section;

[0031] Figure 3 A fluid velocity distribution cloud diagram of a longitudinal section of a vertical shaft type water inlet and outlet structure obtained by using the design method of the vertical shaft type water inlet and outlet structure of the present invention;

[0032] Figure 4 A distribution cloud diagram of the fluid velocity in each flow channel of the vertical shaft type water inlet and outlet structure obtained by adopting the design method of the vertical shaft type water inlet and outlet structure of the present invention;

[0033] Figure 5 It is a fluid velocity distribution cloud diagram of the longitudinal section of the existing vertical shaft type water inlet and outlet structure;

[0034] Figure 6 A cloud diagram of the fluid velocity distribution in each flow channel of the existing vertical shaft type water inlet and outlet structure;

[0035] In the figure: 1-pressurized pipe section, 2-connecting diffusion section, 3-turning section, 4-vertical pipe section, 5-first flow channel, 6-second flow channel, 7-third flow channel, 8-fourth flow channel, 9-fifth flow channel, 10-sixth flow channel, 11-seventh flow channel, 12-eighth flow channel. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] The purpose of the present invention is to provide a design method and a shaft-type water inlet and outlet structure to solve the problem of uneven flow distribution in each flow channel caused by the influence of biased flow in the turning section, so as to ensure the safe and stable operation of hydraulic and hydropower projects.

[0038] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0039] Embodiment 1

[0040] like Figure 1 As shown, this embodiment provides a design method for a vertical shaft type water inlet and outlet structure, comprising the following steps:

[0041] Step 1: According to the actual project operation conditions, the initial shape design of the shaft-type water inlet and outlet structure is carried out, and the basic design parameters of the initial shape of the shaft-type water inlet and outlet structure are as follows: the diameter of the pressurized pipe section 1 is d1=7.20m, and the diameter of the starting end section connecting the diffuser section 2 is d k1 =7.21m, the diameter of the end section connected to the diffuser section 2 is d k2 =10.00m, the diameter of the vertical pipe section 4 is d2 = 7.50m;

[0042] Step 2: Determine the cross-sectional diameter d of the starting end of the turning section 3 z1 and the end section diameter d of the turning section 3 z2 , d z1 =d k2 =10.00m,d z2 =d2=7.50m;

[0043] Step 3: Calculate the turning radius R of turning section 3 m , the inner radius R of turning section 3 in , the turning outer diameter R of turning section 3 ex, calculate the length L of the connecting diffusion section 2;

[0044] In this embodiment, the turning radius R of the turning section 3 is m The formula is as follows:

[0045] R m =α·d1

[0046] Wherein, α is the turning radius coefficient, which ranges from 2.1 to 2.2. In this embodiment, it is 2.15. The turning radius R of the turning section 3 is calculated. m =15.50m;

[0047] In this embodiment, the inner radius R of the turning section 3 is in The formula is as follows:

[0048] R in =β·d1

[0049] Among them, β is the inner diameter coefficient of the turn, β = 0.8871·α, and the inner diameter R of the turn section 3 is calculated as in =13.75m;

[0050] In this embodiment, the turning outer diameter R of the turning section 3 is ex The formula is as follows:

[0051] R ex =γ·d1

[0052] Among them, γ is the turning outer diameter coefficient, γ = 1.1987·α, and the turning outer diameter R of turning section 3 is calculated ex =18.58m;

[0053] In this embodiment, the turning angle θ of the turning section 3 (the turning angle is the angle between the starting end section of the turning section 3 and the end section of the turning section 3) is 90°;

[0054] In this embodiment, the formula for the length L of the connecting diffuser section 2 is as follows:

[0055]

[0056] In this embodiment, the diffusion angle of the connecting diffusion section 2 is (The diffusion angle of the connecting diffuser section 2 is the angle between the inner wall of the connecting diffuser section 2 and the center line of the connecting diffuser section 2) has a value range of The value is set according to the flow rate;

[0057] In this embodiment, Take 5.3° and calculate the length of the connecting diffuser section 2, L = 15m;

[0058] Step 4: Based on the turning radius R of turning segment 3 m , the inner radius R of turning section 3 in , the turning outer diameter R of turning section 3 ex , the turning angle θ of the turning section 3, the length L of the connecting diffuser section 2 and the diffusion angle of the connecting diffuser section 2 Verify in 3D design software.

[0059] This embodiment clarifies the design method of the turning section 3 in the shaft-type water inlet and outlet structure through the turning radius coefficient, the turning inner diameter coefficient and the turning outer diameter coefficient; in addition, the diffusion angle connecting the diffusion section 2 is also introduced. The vertical shaft type water inlet and outlet structure obtained by the design method of the vertical shaft type water inlet and outlet structure of this embodiment can effectively solve the problem of uneven flow distribution of each flow channel caused by the deviation effect of the turning section 3, thereby saving the workload of the designers, improving the optimization efficiency, and ensuring the safe and stable operation of the project.

[0060] Embodiment 2

[0061] like Figure 1 As shown, this embodiment provides a vertical shaft type water inlet and outlet structure obtained by adopting the design method of the vertical shaft type water inlet and outlet structure of the first embodiment, which includes a pressurized pipe section 1, a connecting diffuser section 2, a turning section 3, a vertical pipe section 4, a bell mouth section and a trash rack section connected in sequence according to the outlet flow direction, and the trash rack section is provided with flow channels evenly distributed along the circumference of the trash rack section. The cross-sectional diameter of the starting end of the turning section 3 is equal to the cross-sectional diameter of the end of the connecting diffuser section 2, and the cross-sectional diameter of the end of the turning section 3 is equal to the diameter of the vertical pipe section 4. The center line of the connecting diffuser section 2 is perpendicular to the center line of the vertical pipe section 4.

[0062] Comparative Example

[0063] When the unit is in dual operation, according to the current design manual and specifications, the turning radius of the turning section 3 is designed to be 2.77 times the diameter of the pressurized tunnel. The longitudinal section velocity distribution of the shaft-type inlet and outlet structure using the existing turning section 3 and the velocity distribution of the fluid in each flow channel are analyzed. Figure 5 and Figure 6 As shown in Table 1, due to the bend flow deviation effect, the flow velocity entering the vertical pipe section 4 is unevenly distributed, which leads to the fluid flow velocity of the four flow channels (third flow channel 7, fourth flow channel 8, fifth flow channel 9, and sixth flow channel 10) near the outside of the turning section 3 being significantly greater than the fluid flow velocity of the four flow channels (first flow channel 5, second flow channel 6, third flow channel 7, and fourth flow channel 8) inside the turning section 3, ultimately leading to uneven distribution of fluid flow in each flow channel, as shown in Table 1. The turning section 3 of the prior art causes the flow diversion of each orifice of the inlet and outlet to be significantly uneven, which is not conducive to the safe and stable operation of the project.

[0064] After the design method of the vertical shaft type water inlet and outlet structure of this embodiment is adjusted, Figure 3 As shown, the flow velocity of the fluid entering the vertical pipe section 4 is uniformly distributed in the transverse direction; Figure 4 As shown, the flow velocity distribution of the fluid entering each flow channel becomes uniform, thereby improving the uniformity of the fluid flow distribution in each flow channel.

[0065] Table 1 Comparison of fluid flow distribution in each flow channel under outflow conditions between this embodiment and the original solution

[0066]

[0067] The flow distribution of the fluid in each flow channel under the outflow condition of this embodiment and the original solution is shown in Table 1. It can be seen that after redesigning the turning section 3 and the vertical pipe section 4 according to the method of this embodiment, the problem of uneven flow distribution caused by the bend flow deviation effect of the vertical shaft type inlet and outlet structure is solved.

[0068] Embodiment 3

[0069] When the unit is running alone, the operating flow rate is reduced to 59.2m 3 / s, Take 3.2°, calculate the length of the connecting diffusion section 2 L = 25m, and get the flow split ratios of each flow channel as 10.91%, 11.19%, 14.70%, 11.59%, 15.71%, 13.56%, 13.67%, 8.67% respectively. By observing the comparison results in Table 2, it can be seen that when a single unit is running, the inlet and outlet flow rates decrease, and the flow split ratios of each flow channel in the prior art range from 7.32% to 19.01%, and the flow distribution is uneven. In contrast, the present invention adjusts the length of the connecting diffusion section so that the flow split ratios of each flow channel range from 8.67% to 15.71%, which significantly improves the problem of uneven flow distribution when a single unit is running.

[0070] Table 2 Comparison of fluid flow distribution in each flow channel under outflow conditions between this embodiment and the original solution

[0071]

[0072] To further prove the reliability of this embodiment, the vertical shaft type water inlet and outlet structure of this embodiment was manufactured by 3D printing technology, and the test was carried out to monitor the fluid flow distribution of each flow channel of the vertical shaft type water inlet and outlet structure under the dual-machine and single-machine operation flow rates. Table 3 is a comparison of the test value and the numerical simulation value results of the diversion ratio of each flow channel of the vertical shaft type water inlet and outlet structure. By observing the comparison results in Table 3, it can be seen that the distribution law of the numerical simulation value is consistent with the test value, which proves the reliability of the design method of the vertical shaft type water inlet and outlet structure of this embodiment.

[0073] Table 3 Comparison of experimental and simulated values ​​of fluid flow distribution in each flow channel under different operating flow rates of the vertical shaft inlet and outlet structure

[0074]

[0075] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. The design method of the vertical shaft type water inlet and outlet structure is characterized by: The following steps are involved: Step 1: According to the actual project operation conditions, the initial shape design of the shaft-type water inlet and outlet structure is carried out, and the basic design parameters of the initial shape of the shaft-type water inlet and outlet structure are as follows: the diameter of the pressurized pipe section is d1, and the diameter of the starting end section connecting the diffusion section is d k1 The diameter of the end section connecting the diffuser is d k2 , the diameter of the vertical pipe section is d2; Step 2: Determine the cross-sectional diameter d of the starting end of the turning section z1 and the end section diameter d of the turning section z2 , d z1 =d k2 , d z2 =d2; Step 3: Calculate the turning radius R of the turning section m , the inner radius R of the turning section in , the turning outer diameter R of the turning section ex , calculate the length L of the connecting diffusion section; Step 4: Turning radius R based on the turning section m , the inner radius R of the turning section in , the turning outer diameter R of the turning section ex , the turning angle θ of the turning section, the length L of the connecting diffuser section and the diffusion angle of the connecting diffuser section Verify in 3D design software.

2. The design method of the vertical shaft type water inlet and outlet structure according to claim 1 is characterized in that: Turning radius R of the turning section m The formula is as follows: R m =α·d1 Among them, α is the turning radius coefficient, and its value range is 2.1 to 2.

2.

3. The design method of the vertical shaft water inlet and outlet structure according to claim 2 is characterized in that: The inner radius R of the turning section in The formula is as follows: R in =β·d1 Wherein, β is the inner diameter coefficient of the turn, β = 0.8871·α.

4. The design method of the vertical shaft type water inlet and outlet structure according to claim 2 is characterized in that: The outer radius R of the turning section ex The formula is as follows: R ex =γ·d1 Wherein, γ is the turning outer diameter coefficient, γ = 1.1987·α.

5. The design method of the vertical shaft type water inlet and outlet structure according to claim 1, characterized in that: The turning angle θ of the turning section is 90°.

6. The design method of the vertical shaft type water inlet and outlet structure according to claim 1, characterized in that: The formula for the length L of the connecting diffuser is as follows:

7. The design method of the vertical shaft water inlet and outlet structure according to claim 1, characterized in that: Diffusion angle of the connecting diffuser The value range is 8. A vertical shaft type water inlet and outlet structure obtained by adopting the design method of the vertical shaft type water inlet and outlet structure according to any one of claims 1 to 7, characterized in that: The utility model comprises a pressurized pipe section, a connecting diffusion section, a turning section, a vertical pipe section, a bell mouth section and a trash rack section which are connected in sequence. The trash rack section is provided with flow channels which are evenly distributed along the circumference of the trash rack section.

9. The vertical shaft type water inlet and outlet structure according to claim 8, characterized in that: The center line of the connecting diffuser section is arranged perpendicular to the center line of the vertical pipe section.

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