A kind of partition pier and design method for the outlet channel of a large-scale front-end tubular pump station

Abstract

The present invention discloses a partition pier and design method for the outlet flow channel of a large-scale front-mounted cross-flow pump station, and belongs to the technical field of water conservancy engineering pump station. It is characterized in that: the partition pier is divided into a front part, a middle part and a tail part in the direction of water flow; the front part is located in the middle diffusion transition section of the outlet flow channel, and the middle part and the tail part are located in the outlet gate section of the outlet flow channel; the front part includes a twisting section and a gradual section; the thickness of the middle part of the partition pier is determined according to the gate slot depth and gate slot neck thickness required for installing the gate, and the length of the middle part of the partition pier is determined by the distance between the center lines of the working gate slot and the accident gate slot, and the gate slot width; the three-dimensional shape of the partition pier twisting section is an "S"-shaped twisted surface body, which is designed based on the numerical simulation results of the three-dimensional flow field of the outlet flow channel; the tail of the partition pier is streamlined. The present invention can reduce the head loss of the outlet flow channel of a large-scale front-mounted cross-flow pump station and improve the flow channel efficiency, which is of great significance to ensure the stable and efficient operation of the pump station.

Description

Technical Field

[0001] The present invention belongs to the technical field of water conservancy engineering pump station, and specifically relates to a partition pier and a design method for a water outlet flow channel of a large-scale front-mounted cross-flow pump station, which is used for the design of a partition pier in the water outlet flow channel of a front-mounted cross-flow pump station to eliminate vortices in the water outlet flow channel, reduce the head loss of the flow channel and make the flow state of the water in the flow channel uniform. Background Art

[0002] Large-scale front-mounted tubular pump stations have the advantages of excellent hydraulic performance and low plant height, and are widely used in low-lift pump stations, especially ultra-low-lift pump stations. Large-scale front-mounted tubular pump stations need to be equipped with working gates and emergency gates at the outlet of the water flow channel, so that the gates can be quickly closed to cut off the water flow when the pump unit is shut down to prevent the pump unit from reversing and escaping. In order to prevent the motor from overpowering when the large-scale front-mounted tubular pump station is started, several small flap gates are usually opened on the working gates, so that when the water pump is started, the water flow will open the small flap gates to reduce the starting power of the motor. The outlet width of the water flow channel of large-scale front-mounted tubular pump stations is large. In order to reduce the gate width of the outlet of the water flow channel and meet the requirements of the stability of the water flow channel structure, a middle partition pier is usually set in the water flow channel to divide the original large-width gate into two small-width gates to facilitate the rapid closing and opening of the gate. The setting of the middle partition pier divides the flow channel at the outlet of the water flow channel into two holes. Looking along the water flow direction, one is the left hole and the other is the right hole. The middle partition pier of the water flow channel is arranged vertically along the water flow direction. The length of the middle partition pier is determined according to the requirements of the gate layout and structure. The thickness direction of the middle partition pier is the same as the width direction of the water flow channel. The head and tail of the middle partition pier are both semicircular and the middle is rectangular.

[0003] During the operation of the water pump, there is a velocity circulation in the water flow at the outlet of the water pump guide vane body. The water flows into the outlet flow channel in a spiral shape. When the rotating water flow encounters the vertical semicircular head of the middle pier, a vortex area exists at the upper part of the left hole and the lower part of the right hole of the outlet flow channel near the middle pier. The existence of this vortex will cause the flapper on the working gate to operate unsteadily when the water pump is started, and greatly increase the head loss of the outlet flow channel, reduce the flow channel efficiency, and affect the stable and efficient operation of the water pump device. Summary of the invention

[0004] The present invention aims at the defects of the prior art and provides a partition pier and design method for the outlet flow channel of a large-scale front-mounted cross-flow pump station, so as to ensure that the water in the outlet flow channel of the designed large-scale front-mounted cross-flow pump station flows smoothly without vortexes, thereby ensuring the safe, stable and efficient operation of the pump station.

[0005] To achieve the first object of the present invention, the following technical solution is adopted:

[0006] A partition pier for a water outlet channel of a large-scale front-mounted tubular pump station is characterized in that the water outlet channel of the large-scale front-mounted tubular pump station is divided into an inlet truncated cone section, an intermediate diffusion transition section and an outlet gate section in sequence from the inlet to the outlet along the water flow direction, and a partition pier is arranged in the water outlet channel;

[0007] The longitudinal centerline of the middle pier coincides with the longitudinal centerline of the outlet channel, the thickness direction of the middle pier is the same as the width direction of the outlet channel, and the length of the middle pier is determined by the length of the outlet gate section and the requirements for the stability of the outlet channel structure;

[0008] The middle partition pier is divided into a front part, a middle part and a tail part in the direction of water flow, the front part is located in the middle diffusion transition section of the outlet flow channel, the middle part and the tail part are located in the outlet gate section of the outlet flow channel; the front part includes a twisting section and a gradient section, the inlet of the gradient section is connected with the outlet of the twisting section, the outlet of the gradient section is connected with the inlet of the middle part, and the outlet of the middle part is connected with the inlet of the tail part.

[0009] Preferably, the top of the twisted section of the partition pier in the outlet flow channel is "S"-shaped, and the outlet of the twisted section is a rectangular surface; the shape of the twisted section is an "S"-shaped twisted surface body;

[0010] Preferably, the gradual transition section of the partition pier in the outlet flow channel is a diffusion section, the cross section of which gradually increases from the inlet direction to the outlet direction, and the diffusion angle of the gradual transition section is less than or equal to the plane diffusion angle of the outlet flow channel.

[0011] Preferably, the cross section of the middle part of the middle pier is a rectangle of equal width. The middle part of the middle pier is provided with door slots on both sides near the inlet to cooperate with the working gate, and door slots on both sides near the outlet to cooperate with the emergency gate.

[0012] Preferably, the thickness B of the middle portion of the middle partition pier is gz According to the gate groove depth B required for installing the gate mc and groove neck thickness B cj OK, B gz =2B mc +B cj ; The length L of the middle part of the middle pier gz The distance L between the center line of the working gate slot and the accident gate slot mm , Gate slot width H mc OK, L gz =L mm +H mc +0.5+0.5, unit is m;

[0013] Preferably, the tail of the middle pier is streamlined to eliminate the low-speed area caused by the semicircular pier tail.

[0014] Preferably, the twisted section of the middle pier has a complex shape and is made of steel in the factory, while the gradient section, the middle part and the tail part have simple shapes and are cast in concrete on site; the manufactured twisted section of the middle pier is transported to the site for positioning and installation, and the twisted section is welded to the steel bars tied at the inlet of the gradient section, and finally concrete is cast to form a complete middle pier.

[0015] To achieve the second purpose of the present invention, the following technical solution is adopted:

[0016] A design method for a partition pier in a water outlet channel of a large-scale front-mounted tubular pump station is characterized by comprising the following steps:

[0017] 1. The outlet flow channel of the large-scale front-end cross-flow pump station is divided into an inlet frustum section, an intermediate diffusion transition section and an outlet gate section from the inlet to the outlet along the water flow direction, and a middle partition pier is set in the outlet flow channel;

[0018] 2. The longitudinal centerline of the middle pier coincides with the longitudinal centerline of the outlet channel, the thickness direction of the middle pier is the same as the width direction of the outlet channel, and the length L of the middle pier is g The length of the exit gate section L cz and the length L required for the stability of the outlet channel structure w Jointly determined, L g =L cz +L w ;

[0019] 3. According to the role of the middle pier in the outlet flow channel, the middle pier is divided into the front part, the middle part and the tail part in the direction of the water flow, the front part is located in the middle diffusion transition section of the outlet flow channel, the middle part and the tail part are located in the outlet gate section of the outlet flow channel; the front part includes a twisting section and a gradual section;

[0020] 4. The middle part of the middle pier must be thick enough to install the working gate and the emergency gate. The thickness of the middle part of the middle pier is B gz According to the gate groove depth B required for installing the gate mc and groove neck thickness B cj OK, B gz =2B mc +B cj , the groove neck thickness B cj The minimum value is 0.3m to meet the needs of structural strength and concrete pouring; the length L of the middle part of the middle pier gz The distance L between the center line of the working gate slot and the accident gate slot mm , Gate slot width H mc OK, L gz =L mm +H mc +0.5+0.5, unit is m;

[0021] 5. The tail of the middle pier is streamlined to prevent the generation of Karman vortex at the tail of the middle pier and increase the head loss of the outlet flow channel. The profile of the tail of the middle pier is divided into a left line and a right line, which are represented by a cross-section position diagram and a cross-section data table;

[0022] 6. The intermediate pier gradient section is a diffusion section, the gradient section outlet is connected to the middle inlet, and the gradient section inlet is connected to the twisted section outlet, so that the water flow diffuses smoothly; the diffusion angle of the gradient section is θ gj In order to prevent the water flow in the left and right holes of the outlet channel from shrinking, the diffusion angle θ of the transition section of the middle partition pier is required to be gj Less than or equal to the diffusion angle θ of the outlet channel plane cp The length of the transition section of the intermediate pier is L gj , the thickness of the gradient section inlet is B gj The minimum value is 0.2m to meet the needs of concrete pouring; according to the diffusion angle θ of the gradient section gj Length L gj and inlet section thickness B gj Draw a single-line diagram of the gradient segment;

[0023] 7. According to the water flow velocity distribution at the top of the middle pier twisted section of the outlet flow channel, the three-dimensional shape of the middle pier twisted section is designed to adjust the flow direction of the rotating water flow; the top of the middle pier twisted section is "S" shaped, and the outlet of the twisted section is a rectangular surface connected to the inlet of the gradient section; the length of the twisted section is L gt =L w -L gj The three-dimensional shape of the twisted section is an "S"-shaped twisted surface. The middle partition pier twisted section is designed based on the numerical simulation results of the three-dimensional flow field of the outlet flow channel, and the following steps are adopted:

[0024] (1) Based on the numerical simulation method of three-dimensional turbulent flow in the outlet flow channel, the flow field of the outlet flow channel of a large-scale front-end tubular pump station without a pier was numerically calculated;

[0025] (2) According to the numerical calculation results, the flow field at the top of the twisted section of the middle pier is taken and recorded as the TT section;

[0026] (3) Divide the vertical bisector of the TT section into 2n equal parts, where n is a natural number greater than 4, and number the points of equal division from top to bottom as 1, 2, 3, ..., 2n+1;

[0027] (4) Obtain the flow velocity magnitudes in the x, y, and z directions of the positions of the 1st to 2n+1st points in the TT cross-section flow field obtained in step (2) in sequence; the positive direction of x is from the inlet of the outlet flow channel to the outlet in the horizontal plane, the positive direction of y is from the right side to the left side along the water flow direction in the horizontal plane, and the positive direction of z is perpendicular to the horizontal plane and from the bottom to the top;

[0028] (5) Based on the flow velocities in the x, y, and z directions of each equally divided point, calculate the angle between the absolute velocity direction of each point and the x direction, denoted as θ i , i=1,2,3,……,2n+1;

[0029] (6) The twisted section of the middle pier is equally divided in the z direction at the locations of the equally divided points to obtain 2n+1 cross sections, each of which is a curved triangle. The origin of the coordinates of each cross section is denoted as O. i , i=1,2,3,……,2n+1; determine the position of each cross-section vertex, the coordinate of each cross-section vertex in the x direction is 0; the distance between the first cross-section vertex and the 2n+1 cross-section vertex in the y direction is 2*B gj , divide the distance between the first section vertex and the 2n+1 section vertex in the y direction into 2n equal parts, each of which is B gj / n; Based on this, the coordinates of the vertices of the 1st section to the 2n+1th section are Where i=1,2,3,……,2n+1;

[0030] (7) Divide the curve triangle of each section into a left side line and a right side line, and determine the coordinates of the ends of the left side line and the right side line of each section; the coordinates of the ends of the left side line of each section are (L gt , B gj / 2), the coordinates of the end of the right side line of each section are (L gt , -B gj / 2);

[0031] (8) Calculate the left side line of each section; use the curve equation y to calculate the left side line of the i-th section. zi =y zi (x) represents that the curve equation is based on the angle θ of the absolute flow velocity direction at the vertex of the i-th section i , section vertex coordinates The left line end coordinate (L gt , B gj / 2) and the gradient diffusion angle θ gj We get: Each curve equation has 5 undetermined coefficients:

[0032] y zi =a zi +b zi x+czi x 2 +d zi x 3 +e zi x 4 (1)

[0033] In the formula, a zi , b zi 、c zi d zi and e zi (i=1,2,3,……,2n+1) is the coefficient to be determined;

[0034] The left line y of the i-th section zi =y zi The vertices and ends of (x) must satisfy boundary conditions: ① The vertices pass through Point;②The slope of the tangent line at the vertex is equal to tanθ i , to ensure that the water flow direction flows along the vertex tangent direction to avoid water flow separation and vortex generation; ③ The end passes through (L gt , B gj / 2) point; ④The slope of the tangent line at the end is equal to tan(θ gj / 2) to ensure smooth transition between the water flow and the transition section of the middle pier;

[0035] For zi =y zi (x) introduces an adjustment point, and selects the appropriate adjustment point coordinates (x zti ,y zti ) to ensure that the obtained curve can smoothly and orderly adjust the water flow direction and prevent the flow from being separated and forming a vortex in the left hole of the water outlet channel; by introducing the adjustment point, a closed set of equations can be established for the left side line of the i-th section, thereby obtaining the undetermined coefficients of the curve equation of the left side line of the i-th section, and obtaining the curve equation y of the left side line of the i-th section zi =y zi (x);

[0036] (9) Calculate the right side line of each section; use the curve equation y to calculate the right side line of the i-th section. yi =y yi (x) represents that the curve equation is based on the angle θ of the absolute flow velocity direction at the vertex of the i-th section. i , section vertex coordinates The right line end coordinate (L gt , -B gj / 2) and the gradient diffusion angle θ gj We get: Each curve equation has 5 undetermined coefficients:

[0037] yyi =a yi +b yi x+c yi x 2 +d yi x 3 +e yi x 4 (2)

[0038] In the formula, a yi , b yi 、c yi ,d yi and e yi (i=1,2,3,……,2n+1) is the coefficient to be determined;

[0039] The right side line y of the i-th section zi =y zi The vertices and ends of (x) must satisfy boundary conditions: ① The vertices pass through Point;②The slope of the tangent line at the vertex is equal to tanθ i , to ensure that the water flow direction flows along the vertex tangent direction to avoid water flow separation and vortex generation; ③ The end passes through (L gt , -B gj / 2) point; ④The slope of the tangent line at the end is equal to tan(-θ gj / 2) to ensure smooth transition between the water flow and the transition section of the middle pier;

[0040] For yi =y yi (x) introduces an adjustment point, and selects the appropriate adjustment point coordinates (x yti ,y yti ) to ensure that the obtained curve can smoothly and orderly adjust the water flow direction and prevent the flow from being separated and forming a vortex in the right hole of the water outlet channel; through the introduced adjustment points, a closed set of equations can be established for the right side line of the i-th section, thereby obtaining the undetermined coefficients of the curve equation of the right side line of the i-th section;

[0041] (10) According to the left side curve equation of each section, the left side curve of each section is represented by coordinate data and a cross-sectional position diagram to facilitate layout and processing during production;

[0042] (11) According to the right side curve equation of each section, the right side curve of each section is represented by coordinate data and a cross-sectional position diagram to facilitate layout and processing during production;

[0043] (12) The cross sections of the twisted section of the middle pier are smoothly connected in the z direction to form an "S"-shaped twisted surface;

[0044] 8. The shape of the twisted section of the middle pier is complex and is made of steel in the factory, while the shapes of the gradient section, the middle part and the tail part are simple and are cast in concrete on site. The manufactured twisted section of the middle pier is transported to the site for positioning and installation, and the steel bars tied to the entrance of the twisted section and the gradient section are welded, and finally concrete is cast to form a complete middle pier.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] First, in response to the defects of the existing partition pier design method, the present invention proposes a partition pier and design method for the outlet flow channel of a front-mounted cross-flow pump station. The designed partition pier can effectively adjust the flow state of the outlet flow channel, eliminate vortices, and ensure the stable operation of the pump station.

[0047] Secondly, the middle partition pier designed by the present invention can reduce the head loss of the water outlet channel, improve the efficiency of the pump device, reduce the energy consumption of the pump station operation, and save operating costs.

[0048] Thirdly, the partition pier design method provided by the present invention has strong applicability. According to the method of the present invention, a partition pier that improves the flow state of the water outlet channel can be easily designed, which is convenient for a large number of engineering and technical personnel to adopt. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] FIG. 1( a ) is a schematic diagram of the three-dimensional shape of the outlet flow channel of the front-mounted tubular pump station of the present invention;

[0050] FIG1( b ) is a schematic diagram of the three-dimensional shape of the intermediate pier of the present invention;

[0051] Figure 2 It is a schematic diagram of the three-dimensional shape of the front part of the partition pier in the present invention;

[0052] Figure 3 It is a schematic plan view of the middle part of the partition pier of the present invention;

[0053] Figure 4 It is a cross-sectional position diagram of the tail of the partition pier in the present invention;

[0054] Figure 5 It is a schematic diagram of the dimensions of the gradual change section of the partition pier in the present invention;

[0055] FIG6( a ) is a schematic diagram showing the position of the TT section in the flow channel elevation diagram in the present invention;

[0056] FIG6( b ) is a schematic diagram showing the position of the TT section in the flow channel plane view in the present invention;

[0057] FIG6( c ) is a schematic diagram of the TT section in the present invention;

[0058] Figure 7 A cross-sectional position diagram of the twisted section of the partition pier in an embodiment of the present invention;

[0059] FIG8(a) is a cross-sectional position diagram of the left and right lines of the cross section of the partition pier twisting section 1-1 according to an embodiment of the present invention;

[0060] FIG8( b ) is a cross-sectional position diagram of the left and right lines of the cross section of the partition pier twisting section 2 - 2 according to an embodiment of the present invention;

[0061] FIG8(c) is a cross-sectional position diagram of the left and right lines of the cross section of the partition pier twisting section 3-3 according to an embodiment of the present invention;

[0062] FIG8(d) is a cross-sectional position diagram of the left and right lines of the cross section of the partition pier twisting section 4-4 according to an embodiment of the present invention;

[0063] FIG8(e) is a cross-sectional position diagram of the left and right lines of the cross section of the partition pier twisting section 5-5 according to an embodiment of the present invention;

[0064] FIG8( f ) is a cross-sectional position diagram of the left and right lines of the cross section of the partition pier twisting section 6 - 6 according to an embodiment of the present invention;

[0065] FIG8(g) is a cross-sectional position diagram of the left and right lines of the cross section of the partition pier twisting section 7-7 according to an embodiment of the present invention;

[0066] FIG8(h) is a cross-sectional position diagram of the left and right lines of the cross section of the partition pier twisting section 8-8 according to an embodiment of the present invention;

[0067] FIG8(i) is a cross-sectional position diagram of the left and right lines of the cross section of the partition pier twisting section 9-9 according to an embodiment of the present invention;

[0068] FIG8(j) is a cross-sectional position diagram of the left and right lines of the cross section of the partition pier twisting section 10-10 according to an embodiment of the present invention;

[0069] FIG8(k) is a cross-sectional position diagram of the left and right lines of the cross section of the partition pier twisting section 11-11 according to an embodiment of the present invention;

[0070] Fig. 9 The flow field diagram of the conventional water outlet channel of the middle partition pier is adopted;

[0071] Fig.10 Flow field diagram of the water outlet channel using the partition pier of the present invention;

[0072] In the figure: 1 inlet cone section, 2 middle diffusion transition section, 3 outlet gate section, 4 middle partition pier, 5 front part, 51 twisted section, 511 left line, 512 right line, 52 gradient section, 6 middle part, 7 tail part, 71 left line of tail part, 72 right line of tail part, 8 gate slot, 81 center line of gate slot of working gate, 82 center line of gate slot of emergency gate, 9 slot neck. DETAILED DESCRIPTION

[0073] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0074] A large-scale front-type tubular pump station outlet flow channel partition pier, which is characterized by:

[0075] 1. The outlet flow channel of a large-scale front-end tubular pump station is divided into an inlet cone section 1, an intermediate diffusion transition section 2 and an outlet gate section 3 in sequence from the inlet to the outlet along the water flow direction, and a middle partition pier 4 is set in the outlet flow channel, as shown in FIG1(a);

[0076] 2. The longitudinal centerline of the middle pier 4 coincides with the longitudinal centerline of the outlet channel, the thickness direction of the middle pier 4 is the same as the width direction of the outlet channel, and the length of the middle pier 4 is determined by the length of the outlet gate section 3 and the requirement for the stability of the outlet channel structure;

[0077] 3. The middle pier 4 is divided into a front part 5, a middle part 6 and a tail part 7 in the direction of water flow, as shown in FIG1(b); the front part 5 is located in the diffusion transition section 2 of the outlet flow channel, and the middle part 6 and the tail part 7 are located in the outlet gate section 3 of the outlet flow channel; the front part 5 includes a twisting section 51 and a gradual section 52, as shown in FIG1(b); Figure 2 As shown;

[0078] 4. The top of the twisted section 51 of the partition 4 in the outlet flow channel is "S" shaped, and the outlet of the twisted section 51 is a rectangular surface; the shape of the twisted section 51 is an "S" shaped twisted surface body, and a cross-sectional position diagram and a data table are provided;

[0079] 5. The cross section of the gradient section 52 of the partition 4 in the water outlet flow channel gradually increases, the inlet of the gradient section 52 is connected with the outlet of the twisted section 51, and the outlet of the gradient section 52 is connected with the inlet of the middle part 6, so that the water flow diffuses smoothly;

[0080] 6. Such as Figure 3 As shown, the thickness B of the middle portion 6 of the intermediate pier 4 is gz According to the depth B of the gate groove 8 required for installing the gate mc and the thickness B of the groove neck 9 cj OK, B gz =2B mc +B cj ; The length L of the middle part 6 of the middle pier gz The distance L between the center line 81 of the working gate slot and the center line 82 of the emergency gate slot is mm , the width H of the gate slot 8 mc OK, L gz =L mm +H mc +0.5+0.5, unit: m;

[0081] 7. The tail 7 of the middle partition pier 4 is streamlined to eliminate the low-speed area produced by the semicircular partition pier tail;

[0082] 8. The twisted section 51 of the middle pier 4 has a complex shape and is made of steel in the factory, while the gradient section 52, the middle section 6 and the tail 7 have simple shapes and are cast in concrete on site. The manufactured twisted section 51 of the middle pier 4 is transported to the site for positioning and installation, and the twisted section 51 is welded to the steel bars tied at the inlet of the gradient section 52, and finally concrete is cast to form a complete middle pier.

[0083] Example

[0084] A large low-lift pump station has a design head of 3m and a single pump design flow of 33.4m 3 / s, it is planned to use a front shaft type through-flow pump station. The length of the outlet flow channel of the pump station is 26.5m, of which the length of the inlet truncated cone section 1 is 2m, the length of the middle diffusion transition section 2 is 15.8m, and the length of the outlet gate section 3 is 8.7m; the plane diffusion angle θ of the middle diffusion transition section 2 cp The distance between the center line 81 of the working gate slot and the center line 82 of the accident gate slot is 4.5m, the width of the slot 8 is 1m, the depth of the slot 8 is B mc is 0.5m, the thickness B of the door slot neck 9 cj The width of the outlet section of the water outlet is 8.75m and the height is 4.24m. According to the design requirements of the water outlet, the method of the present invention is used to design the middle partition pier of the water outlet.

[0085] The steps of designing the partition pier in the outlet channel of the pump station using the method provided by the present invention are as follows:

[0086] 1. The three-dimensional shape of the outlet flow channel of the front shaft type tubular pump station is shown in FIG1(a). From the inlet to the outlet along the water flow direction, it is divided into an inlet frustum section 1, an intermediate diffusion transition section 2 and an outlet gate section 3, and a middle partition pier 4 is arranged in the outlet flow channel;

[0087] 2. The length L of the intermediate pier 4 g The length L of the outlet gate section 3 cz =8.7m and the length L required for the stability of the outlet channel structure w =7.6m, the length of the middle pier 4 is determined by g =L cz +L w =8.7+7.6=14.3m;

[0088] 3. The middle partition pier 4 is divided into a front part 5, a middle part 6 and a tail part 7 in the direction of water flow, as shown in FIG1(b); the front part 5 is located in the middle diffusion transition section 2 of the outlet flow channel, and the middle part 6 and the tail part 7 are located in the outlet gate section 3 of the outlet flow channel, as shown in FIG1(a); the front part 5 includes a twisting section 51 and a gradual section 52, as shown in FIG1(b); Figure 2 As shown;

[0089] 4. The thickness B of the middle part 6 of the middle partition 4 gz According to the depth B of the gate groove 8 required for installing the gate mc =0.5 and the thickness B of the groove neck 9 cj =0.4m confirmed, B gz =2B mc +B cj =1.4m; the length L of the middle part 6 of the intermediate pier 4 gz The distance L between the center line 81 of the working gate slot and the center line 82 of the emergency gate slot is mm =4.5m, width H of door slot 8 mc =1m, the length L of the middle part 6 gz =L mm +H mc +0.5+0.5=6.5m, e.g. Figure 3 As shown;

[0090] 5. The tail 7 of the middle pier 4 is streamlined to prevent the generation of Karman vortex behind the tail 7 of the middle pier and increase the head loss of the outlet flow channel. The profile of the tail 7 of the middle pier 4 is represented by a cross-sectional position diagram and cross-sectional data. The profile of the tail 7 is divided into a left line 71 and a right line 72. The profile cross-sectional position is as follows: Figure 4 As shown, the cross-sectional data are listed in Table 1;

[0091] Table 1: Cross-sectional data of the plane profile of the tail of the middle partition pier Unit: m

[0092]

[0093] 6. The gradient section 52 of the middle partition 4 is a diffusion section, the outlet of the gradient section 52 is connected to the inlet of the middle section 6, and the inlet of the gradient section 52 is connected to the outlet of the twisting section 51; the diffusion angle θ of the gradient section 52 is gj =6°, which is smaller than the plane diffusion angle θ cp =18°, the total length of the front part 5 of the middle partition 4 is 7.6m, and the length of the gradient section 52 is L gj =5.1m, then the thickness of the inlet section of the gradient section 52 is Meet the needs of concrete pouring; according to the plane diffusion angle θ of the gradient section 52 gj Length L gj and inlet section thickness B gj Draw a single line diagram of the gradient segment 52, such as Figure 5 As shown;

[0094] 7. According to the water flow velocity distribution at the position of the twisted section 51 of the middle pier 4 in the water outlet channel, the three-dimensional shape of the twisted section 51 of the middle pier 4 is designed to adjust the flow direction of the rotating water flow; the top of the twisted section 51 of the middle pier 4 is "S" shaped, and the outlet of the twisted section 51 is a rectangular surface connected to the inlet of the gradient section 52; the length L of the twisted section 51 gt =L w -L gj = 2.5m; the three-dimensional shape of the twisted section 51 is an "S"-shaped twisted surface, such as Figure 2 As shown, the twisted section 51 of the middle partition pier 4 is designed based on the numerical simulation results of the three-dimensional flow field of the outlet flow channel, and the following steps are adopted:

[0095] (1) Based on the numerical simulation method of three-dimensional turbulent flow in the outlet flow channel, numerical calculation of the outlet flow channel of the pump station without a middle pier was carried out;

[0096] (2) According to the numerical calculation results, the flow field at the top of the twisted section 51 where the partition pier 4 is to be set is taken as the TT section. The position of the TT section in the outlet flow channel is shown in Figures 6(a) and 6(b); the cross-sectional view of the TT section is shown in Figure 6(c);

[0097] (3) As shown in Figure 6(c), the vertical bisector of the TT section is divided into 2n equal parts, where n = 5, and the equal division points are numbered from top to bottom as ①, ②, ③, ..., There are 11 points in total;

[0098] (4) Obtain the flow velocity magnitudes in the x, y, and z directions at the locations of the 1st to 11th points in the TT cross-section flow field obtained in step (2) in turn; the positive x direction is from the inlet of the outlet flow channel to the outlet in the horizontal plane, the positive y direction is from the right side to the left side along the water flow direction in the horizontal plane, and the positive z direction is perpendicular to the horizontal plane and from the bottom to the top;

[0099] (5) Based on the flow velocities in the x, y, and z directions of each equally divided point, calculate the angle θ between the absolute velocity direction of each point and the x direction i The calculation results of the 11 points are θ1 = 58°, θ2 = 46°, θ3 = 34°, θ4 = 22°, θ5 = 10°, θ6 = 0°, θ7 = -10°, θ8 = -22°, θ9 = -34°, θ 10 =-46°,θ 11 =-58°;

[0100] (6) The twisted section 51 of the middle partition pier 4 is equally divided in the z direction according to the positions of the equally divided points, and 11 cross sections are obtained, which are numbered as 1-1 cross section, 2-2 cross section, 3-3 cross section, 4-4 cross section, 5-5 cross section, 6-6 cross section, 7-7 cross section, 8-8 cross section, 9-9 cross section, 10-10 cross section, and 11-11 cross section. The shape of each cross section is a curved triangle, such as Figure 7 As shown; the origin of the coordinates of each section is denoted as O i , i = 1, 2, 3, ..., 11; the distance between the vertices of the 11 cross sections in the x direction is 0; the distance between the vertex of the first cross section and the vertex of the 11th cross section in the y direction is 2B gj = 1.692m, divide the distance from the first section vertex to the 11th section vertex in the y direction into 10 equal parts, each of which is 2B gj / 10=0.169m; accordingly, the coordinates of the vertices of the first to eleventh sections are (0, -0.846), (0, -0.667), (0, -0.508), (0, -0.338), (0, -0.169), (0, 0), (0, 0.169) (0, 0.338), (0, 0.508), (0, 0.667), (0, 0.846);

[0101] (7) Divide the curve triangle of each cross section into a left side line 511 and a right side line 512, and determine the coordinates of the ends of the left side line 511 and the right side line 512 of each cross section; the coordinates of the ends of the left side line 511 of each cross section are (2.5, 0.423), and the coordinates of the ends of the right side line 512 of each cross section are (2.5, -0.423);

[0102] (8) Calculate the left side line 511 of each section; use the curve equation y to calculate the left side line of the i-th section. zi =y zi (x) represents that the curve equation is based on the angle θ of the absolute flow velocity direction at the vertex of the i-th section i , section vertex coordinates Left line end coordinate (L gt , B gj / 2) and the gradient diffusion angle θ gj We get: Each curve equation has 5 undetermined coefficients:

[0103] y zi =a zi +b zi x+c zi x 2 +d zi x 3 +e zi x 4 (1)

[0104] In the formula, a zi , b zi 、c zi ,d zi and e zi (i=1,2,3,……,2n+1) is the coefficient to be determined;

[0105] The left line y of the i-th section zi =y zi The vertices and ends of (x) must satisfy boundary conditions: ① The vertices pass through Point;②The slope of the tangent line at the vertex is equal to tanθ i , to ensure that the water flow direction flows along the vertex tangent direction to avoid water flow separation and vortex generation; ③ The end passes through (L gt , B gj / 2) point; ④The slope of the tangent line at the end is equal to tan(θ gj / 2) to ensure smooth transition between the water flow and the transition section of the middle pier;

[0106] For zi =y zi (x) introduces an adjustment point, and selects the appropriate adjustment point coordinates (x zti ,y zti ) to ensure that the obtained curve can smoothly and orderly adjust the water flow direction and prevent the flow from being separated and forming a vortex in the left hole of the outlet flow channel; by introducing the adjustment point, a closed set of equations can be established for the left side line of the i-th section, thereby obtaining the undetermined coefficients of the curve equation of the left side line of the i-th section, and obtaining the curve equation y of the left side line of the i-th section zi =y zi (x);

[0107] The curve equation y of the left line 511 of the first section z1 =y z1 The boundary conditions satisfied by the vertex and end of (x) are: the vertex passes through the point (0, -0.846), and the slope of the tangent line at the vertex is equal to tanθ i =1.600, the end passes through the point (2.5, 0.423), and the slope of the end tangent is equal to tan(6 / 2)=0.05; the curve equation of the left line 511 of the first section is calculated as:

[0108] y z1 =-0.846+1.6x-0.676x 2 +0.09x 3 +0.002x 4 (1-1)

[0109] The same method is used to obtain the curve equations of the left line 511 from the second section to the eleventh section as follows:

[0110] y z2 =-0.677+1.036x-0.351x 2 +0.057x 3 -0.005x 4 (1-2)

[0111] y z3 =-0.508+0.675x-0.096x 2 -0.017x 3 +0.003x 4 (1-3)

[0112] y z4 =-0.338+0.404x+0.040x 2 -0.039x 3 +0.003x 4 (1-4)

[0113] y z5 =-0.169+0.176x+0.159x 2 -0.068x 3 +0.006x 4 (1-5)

[0114] y z6 =0.000+0.010x+0.178x 2 -0.047x 3 +0.001x 4 (1-6)

[0115] y z7 =0.169-0.087x+0.036x 2 +0.07x 3 -0.022x 4 (1-7)

[0116] y z8 =0.338-0.213x+0.196x 2 -0.041x 3 +0.001x 4 (1-8)

[0117] y z9 =0.508-0.305x+0.172x 2 -0.021x 3 -0.002x 4 (1-9)

[0118] y z10 =0.677-0.404x+0.187x 2 -0.029x 3 +0.001x 4 (1-10)

[0119] y z11 =0.846-0.488x+0.126x 2 +0.017x 3 -0.007x 4 (1-11)

[0120] (9) Calculate the right side line of each section 512; use the curve equation y to calculate the right side line of the i-th section yi =y yi (x) represents that the curve equation is based on the angle θ of the absolute flow velocity direction at the vertex of the i-th section. i , section vertex coordinates The left line end coordinate (L gt , B gj / 2) and the gradient diffusion angle θ gj We get: Each curve equation has 5 undetermined coefficients:

[0121] y yi =a yi +b yi x+c yi x 2 +d yi x 3 +e yi x 4 (2)

[0122] In the formula, a yi , b yi 、c yi ,d yi and e yi (i=1,2,3,……,2n+1) is the coefficient to be determined;

[0123] The right side curve equation of the i-th section is y zi =y zi The vertices and ends of (x) must satisfy boundary conditions: the vertices pass through The slope of the tangent line at the vertex is equal to tanθ i , the end passes through (L gt , -B gj / 2), the slope of the tangent line at the end is equal to tan(-θ gj / 2);

[0124] Foryi =y yi (x) introduces an adjustment point, and selects the appropriate adjustment point coordinates (x yti ,y yti ) to ensure that the obtained curve can smoothly and orderly adjust the water flow direction and prevent the flow from being separated and forming a vortex in the right hole of the water outlet channel; through the introduced adjustment points, a closed set of equations can be established for the right side line of the i-th section, thereby obtaining the undetermined coefficients of the curve equation of the right side line of the i-th section;

[0125] The first section right line 512 curve equation y y1 =y y1 The boundary conditions satisfied by the vertex and end of (x) are: the vertex passes through the point (0, -0.846), and the slope of the tangent line at the vertex is equal to tanθ i , the end passes through the point (2.5, -0.423), and the slope of the end tangent is equal to tan (-6 / 2) = -0.05; the curve equation of the right side line 512 of the first section is calculated as:

[0126] y y1 =-0.846+0.488x-0.126x 2 -0.017x 3 +0.007x 4 (2-1)

[0127] The same method is used to obtain the curve equations of the right side line 512 from the second section to the eleventh section as follows:

[0128] y y2 =-0.677+0.404x-0.187x 2 +0.029x 3 -0.001x 4 (2-2)

[0129] y y3 =-0.508+0.305x-0.172x 2 +0.021x 3 +0.002x 4 (2-3)

[0130] y y4 =-0.338+0.213x-0.196x 2 +0.041x 3 -0.001x 4 (2-4)

[0131] y y5 =-0.169+0.087x-0.036x 2-0.07x 3 +0.022x 4 (2-5)

[0132] y y6 =0.000-0.010x-0.178x 2 +0.047x 3 -0.001x 4 (2-6)

[0133] y y7 =0.169-0.176x-0.159x 2 +0.068x 3 -0.006x 4 (2-7)

[0134] y y8 =0.338-0.404x-0.040x 2 +0.039x 3 -0.003x 4 (2-8)

[0135] y y9 =0.508-0.675x+0.096x 2 +0.017x 3 -0.003x 4 (2-9)

[0136] y y10 =0.677-1.036x+0.351x 2 -0.057x 3 +0.005x 4 (2-10)

[0137] y y11 =0.846-1.6x+0.676x 2 -0.09x 3 -0.002x 4 (2-11)

[0138] (10) Based on the curve equation of the left side line 511 of the first section to the eleventh section, the curve of the left side line 511 of each section is represented by a section position diagram and coordinate data. The section position diagram is shown in Figure 8(a) to Figure 8(k) , coordinate data are listed in Tables 2 to 12;

[0139] (11) According to the curve equation of the right side line 512 of each cross section, the right side line 512 of each cross section is represented by coordinate data and a cross section position diagram. The cross section position diagram is shown in Figure 8(a) to Figure 8(k) , coordinate data are listed in Tables 2 to 12;

[0140] Table 2 Section data of the twisted section of the middle pier 1-1 Left and right side sections Unit: m

[0141]

[0142] Table 3 Section data of the twisted section of the middle pier 2-2 Left and right line sections Unit: m

[0143]

[0144]

[0145] Table 4 Section data of the twisted section of the middle pier 3-3 Left and right line sections Unit: m

[0146]

[0147] Table 5 Section data of the twisted section of the middle pier 4-4 Left and right line sections Unit: m

[0148]

[0149] Table 6 Section data of the twisted section of the middle pier 5-5 Left and right line sections Unit: m

[0150]

[0151]

[0152] Table 7 Section 6-6 of the twisted section of the middle pier, left and right line section data table Unit: m

[0153]

[0154] Table 8 Section data of the twisted section of the middle pier 7-7 Left and right line sections Unit: m

[0155]

[0156] Table 9 Section data of the twisted section of the middle pier 8-8 left and right line sections Unit: m

[0157]

[0158]

[0159] Table 10 Section data of the twisted section of the middle pier 9-9 left and right line sections Unit: m

[0160]

[0161] Table 11 Section data of the twisted section of the middle pier 10-10 left and right lines Unit: m

[0162]

[0163] Table 12 Section data of the twisted section of the middle pier 11-11 left and right line sections Unit: m

[0164]

[0165]

[0166] (12) The cross sections of the twisted sections 51 of the middle partition pier 4 are smoothly connected in the z direction to form an "S"-shaped twisted surface body, such as Figure 2 As shown;

[0167] 8. The designed middle pier 4 is applied to the water outlet channel of the station. The twisted section 51 of the middle pier 4 is made of steel in the factory, and the gradient section 52, the middle section 6 and the tail section 7 are cast with concrete on site; the manufactured twisted section 51 of the middle pier 4 is transported to the site for positioning and installation, and the twisted section 51 is welded with the steel bars tied at the inlet of the gradient section 52, and finally concrete is cast to form a complete middle pier 4;

[0168] 9. The three-dimensional flow field of the outlet channel using conventional intermediate piers is shown in Fig. 9 , there is an obvious vortex area in the flow channel; the flow field of the outlet flow channel using the intermediate pier of the present invention is shown in Fig.10 , the vortex in the flow channel is eliminated, the water flows smoothly and evenly, and the flow state is good.

Claims

1. A large-scale front-type tubular pump station outlet flow channel partition pier, characterized in that: The outlet flow channel is divided into an inlet truncated cone section, an intermediate diffusion transition section and an outlet gate section in sequence from the inlet to the outlet along the water flow direction, and a middle partition pier is arranged in the outlet flow channel; the longitudinal center line of the middle partition pier coincides with the longitudinal center line of the outlet flow channel, and the thickness direction of the middle partition pier is the same as the width direction of the outlet flow channel; The middle pier is divided into a front part, a middle part and a tail part in the direction of water flow, the front part is located in the middle diffusion transition section of the outlet flow channel, and the middle part and the tail part are located in the outlet gate section of the outlet flow channel; the front part includes a twisting section and a gradient section, the inlet of the gradient section is connected with the outlet of the twisting section, the outlet of the gradient section is connected with the inlet of the middle part, and the outlet of the middle part is connected with the inlet of the tail part; The shape of the twisted section is an "S"-shaped twisted surface body, the top of the twisted section inlet is "S"-shaped, and the outlet of the twisted section is a rectangular surface; the intermediate pier gradient section of the outlet flow channel is a diffusion section, and its cross-section gradually increases from the inlet direction to the outlet direction, and the diffusion angle of the gradient section is less than or equal to the diffusion angle of the outlet flow channel plane.

2. According to claim 1, a large-scale front-end crossflow pump station outlet flow channel partition pier is characterized in that: The cross section of the middle portion of the intermediate pier is a rectangle of equal width.

3. The partition pier in the outlet channel of a large-scale front-end crossflow pump station according to claim 2 is characterized in that: The middle part of the intermediate pier is provided with door slots on both sides close to the inlet to cooperate with the working gate, and the middle part of the intermediate pier is provided with door slots on both sides close to the outlet to cooperate with the emergency gate.

4. The partition pier in the outlet channel of a large-scale front-mounted tubular pump station according to claim 3 is characterized in that: The thickness B of the middle part of the middle partition gz According to the gate groove depth B required for installing the gate mc and groove neck thickness B cj OK, B gz =2B mc +B cj ; The length L of the middle part of the middle pier gz The distance L between the center line of the working gate slot and the accident gate slot mm , Gate slot width H mc OK, L gz =L mm +H mc +0.5+0.5, unit is m.

5. The partition pier in the outlet channel of a large-scale front-end tubular pump station according to claim 1 is characterized in that: The tail of the middle pier is streamlined to eliminate the low-speed area produced by the semicircular pier tail.

6. The large-scale front-end type throughflow pump station outlet flow channel partition pier according to claim 1, characterized in that: The twisted section of the middle pier is made of steel, and the gradient section, the middle part and the tail part are cast with concrete; the twisted section and the gradient section are welded with steel bars at the inlet, and finally concrete is cast to form a complete middle pier.

7. A design method for the intermediate pier in the outlet channel of a large-scale front-end tubular pump station, characterized in that: The following steps are involved: (1) The outlet flow channel of a large-scale front-end tubular pump station is divided into an inlet cone section, an intermediate diffusion transition section and an outlet gate section from the inlet to the outlet along the water flow direction, and a middle partition pier is set in the outlet flow channel; (2) The longitudinal centerline of the middle pier coincides with the longitudinal centerline of the outlet channel, the thickness direction of the middle pier is the same as the width direction of the outlet channel, and the length L of the middle pier is g The length of the exit gate section L cz and the length L required for the stability of the outlet channel structure w Jointly determined, L g =L cz +L w ; (3) According to the role of the middle pier in the outlet flow channel, the middle pier is divided into a front part, a middle part and a tail part in the direction of water flow, the front part is located in the middle diffusion transition section of the outlet flow channel, and the middle part and the tail part are located in the outlet gate section of the outlet flow channel; the front part includes a twisting section and a gradual section; (4) The middle part of the intermediate pier must be thick enough to install the working gate and the emergency gate. The thickness of the middle part of the intermediate pier is B gz According to the gate groove depth B required for installing the gate mc and groove neck thickness B cj OK, B gz =2B mc +B cj , the groove neck thickness B cj The minimum value is 0.3m to meet the needs of structural strength and concrete pouring; the length L of the middle part of the middle pier gz The distance L between the center line of the working gate slot and the accident gate slot mm , Gate slot width H mc OK, L gz =L mm +H mc +0.5+0.5, unit is m; (5) The tail of the middle pier is streamlined to prevent the generation of Karman vortices at the tail of the middle pier and increase the head loss of the outlet flow channel. The profile of the tail of the middle pier is divided into a left line and a right line, which are represented by a cross-sectional position diagram and a cross-sectional data table; (6) The intermediate pier gradient section is a diffusion section, the outlet of the gradient section is connected to the middle inlet, and the inlet of the gradient section is connected to the outlet of the twisting section, so that the water flow diffuses smoothly; the diffusion angle of the gradient section is θ gj In order to prevent the water flow in the left and right holes of the outlet channel from shrinking, the diffusion angle θ of the transition section of the middle partition pier is required to be gj Less than or equal to the diffusion angle θ of the outlet channel plane cp The length of the transition section of the intermediate pier is L gj , the thickness of the gradient section inlet is B gj The minimum value is 0.2m to meet the needs of concrete pouring; according to the diffusion angle θ of the gradient section gj Length L gj and inlet section thickness B gj Draw a single-line diagram of the gradient segment; (7) According to the water flow velocity distribution at the top of the middle pier twisted section of the outlet flow channel, the three-dimensional shape of the middle pier twisted section is designed to adjust the flow direction of the rotating water flow; the top of the middle pier twisted section is "S" shaped, and the outlet of the twisted section is a rectangular surface connected to the inlet of the gradient section; the length of the twisted section L gt =L w -L gj ; The three-dimensional shape of the twisted segment is an "S"-shaped twisted surface; (8) The shape of the twisted section of the middle pier is complex and is made of steel in the factory, while the shapes of the gradient section, the middle section and the tail section are simple and are cast in concrete on site. The manufactured twisted section of the middle pier is transported to the site for positioning and installation, and the steel bars tied at the entrance of the twisted section and the gradient section are welded, and finally concrete is cast to form a complete middle pier.

8. The design method of the partition pier in the outlet flow channel of a large-scale front-end cross-flow pump station according to claim 7 is characterized in that: In the step (7), the three-dimensional shape design of the twisted section of the middle partition pier is performed based on the numerical simulation results of the three-dimensional flow field of the outlet flow channel, and the following steps are adopted: (1) Based on the numerical simulation method of three-dimensional turbulent flow in the outlet flow channel, the flow field of the outlet flow channel of a large-scale front-end tubular pump station without a pier was numerically calculated; (2) According to the numerical calculation results, the flow field at the top of the twisted section of the middle pier is taken and recorded as the TT section; (3) Divide the vertical bisector of the TT section into 2n equal parts, where n is a natural number greater than 4, and number the points of equal division from top to bottom as 1, 2, 3, ..., 2n+1; (4) Obtain the flow velocity magnitudes in the x, y, and z directions of the positions of the 1st to 2n+1st points in the TT cross-section flow field obtained in step (2) in sequence; the positive direction of x is from the inlet of the outlet flow channel to the outlet in the horizontal plane, the positive direction of y is from the right side to the left side along the water flow direction in the horizontal plane, and the positive direction of z is perpendicular to the horizontal plane and from the bottom to the top; (5) Based on the flow velocities in the x, y, and z directions of each equally divided point, calculate the angle between the absolute velocity direction of each point and the x direction, denoted as θ i , i=1,2,3,……,2n+1; (6) The twisted section of the middle pier is equally divided in the z direction at the locations of the equally divided points to obtain 2n+1 cross sections, each of which is a curved triangle. The origin of the coordinates of each cross section is denoted as O. i , i = 1, 2, 3, ..., 2n + 1; determine the position of each cross-section vertex, the coordinate of each cross-section vertex in the x direction is 0; the distance between the first cross-section vertex and the 2n + 1 cross-section vertex in the y direction is 2 * B gj , divide the distance between the first section vertex and the 2n+1 section vertex in the y direction into 2n equal parts, each of which is B gj / n; Based on this, the coordinates of the vertices of the 1st section to the 2n+1th section are Where i=1,2,3,……,2n+1; (7) Divide the curve triangle of each section into a left side line and a right side line, and determine the coordinates of the ends of the left side line and the right side line of each section; the coordinates of the ends of the left side line of each section are (L gt , B gj / 2), the coordinates of the end of the right side line of each section are (L gt , -B gj / 2); (8) Calculate the left side line of each section; use the curve equation y to calculate the left side line of the i-th section. zi =y zi (x) represents that the curve equation is based on the angle θ of the absolute flow velocity direction at the vertex of the i-th section i , section vertex coordinates Left line end coordinate (L gt , B gj / 2) and the gradient diffusion angle θ gj We get: Each curve equation has 5 undetermined coefficients: y zi =a zi +b zi x+c zi x 2 +d zi x 3 +e zi x 4 (1) In the formula, a zi , b zi 、c zi ,d zi and e zi (i=1,2,3,……,2n+1) is the coefficient to be determined; The left line y of the i-th section zi =y zi The vertices and ends of (x) must satisfy boundary conditions: ① The vertex passes through (0, Point;②The slope of the tangent line at the vertex is equal to tanθ i , to ensure that the water flow direction flows along the vertex tangent direction to avoid water flow separation and vortex generation; ③ The end passes through (L gt , B gj / 2) point; ④The slope of the tangent line at the end is equal to tan(θ gj / 2) to ensure smooth transition between the water flow and the transition section of the middle pier; For zi =y zi (x) introduces an adjustment point, and selects the appropriate adjustment point coordinates (x zti ,y zti ) to ensure that the obtained curve can smoothly and orderly adjust the water flow direction and prevent the flow from being separated and forming a vortex in the left hole of the water outlet channel; by introducing the adjustment point, a closed set of equations can be established for the left side line of the i-th section, thereby obtaining the undetermined coefficients of the curve equation of the left side line of the i-th section, and obtaining the curve equation y of the left side line of the i-th section zi =y zi (x); (9) Calculate the right side line of each section; use the curve equation y to calculate the right side line of the i-th section. yi =y yi (x) represents that the curve equation is based on the angle θ of the absolute flow velocity direction at the vertex of the i-th section. i , section vertex coordinates The right line end coordinate (L gt , -B gj / 2) and the gradient diffusion angle θ gj We get: Each curve equation has 5 undetermined coefficients: y yi =a yi +b yi x+c yi x 2 +d yi x 3 +e yi x 4 (2) In the formula, a yi , b yi 、c yi ,d yi and e yi (i=1,2,3,……,2n+1) is the coefficient to be determined; The right side line y of the i-th section zi =y zi The vertices and ends of (x) must satisfy boundary conditions: ① The vertices pass through Point;②The slope of the tangent line at the vertex is equal to tanθ i , to ensure that the water flow direction flows along the vertex tangent direction to avoid water flow separation and vortex generation; ③ The end passes through (L gt , -B gj / 2) point; ④The slope of the tangent line at the end is equal to tan(-θ gj / 2) to ensure smooth transition between the water flow and the transition section of the middle pier; For yi =y yi (x) introduces an adjustment point, and selects the appropriate adjustment point coordinates (x yti ,y yti ) to ensure that the obtained curve can smoothly and orderly adjust the water flow direction and prevent the flow from being separated and forming a vortex in the right hole of the water outlet channel; through the introduced adjustment points, a closed set of equations can be established for the right side line of the i-th section, thereby obtaining the undetermined coefficients of the curve equation of the right side line of the i-th section; (10) According to the left side curve equation of each section, the left side curve of each section is represented by coordinate data and a cross-sectional position diagram to facilitate layout and processing during production; (11) According to the right side curve equation of each section, the right side curve of each section is represented by coordinate data and a cross-sectional position diagram to facilitate layout and processing during production; (12) The cross sections of the twisted section of the middle partition pier are smoothly connected in the z direction to form an "S"-shaped twisted surface.

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