Method for reducing siltation of inflow box culvert of laterally arranged rain and sewage drainage pump station
By setting up a combination of partition walls and beam piers in the inlet culvert of the stormwater and sewage drainage pumping station, adjusting the hydraulic flow pattern, and laying out silt drainage ditches and silt drainage pumps in the hole, the problems of siltation and poor flow in the lateral arrangement of stormwater and sewage drainage pumping stations were solved, realizing hydraulic self-cleaning and improving system stability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HOHAI UNIV
- Filing Date
- 2022-11-08
- Publication Date
- 2026-06-02
AI Technical Summary
Laterally arranged stormwater and sewage drainage pumping stations with inlet culverts are prone to adverse hydraulic flow phenomena such as backflow, deflection, and vortex, and serious siltation, which affects the flow area and system safety. Manual dredging is costly and dangerous.
By setting up a combination of partition walls and beam piers in the inlet culvert to adjust the hydraulic flow pattern, and by laying out silt drainage ditches and silt drainage pumps in the hole, hydraulic self-cleaning is achieved, the water flow velocity is evenly distributed, and silt is collected and discharged.
Optimize hydraulic flow patterns, reduce siltation, improve flow capacity, lower manual dredging costs, and ensure system safety and stability.
Smart Images
Figure CN115596065B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of urban stormwater and sewage drainage pumping station engineering technology, and in particular, it is a method for reducing siltation in the inlet culvert of a stormwater and sewage drainage pumping station with a lateral arrangement. Background Technology
[0002] In recent years, with the rapid development of society, economy, and industrial technology, my country has entered a stage of rapid urbanization. However, the dense population, industrial agglomeration, and expansion of urban scale have brought many negative impacts to cities, among which floods and water environment deterioration have become increasingly prominent. Urban drainage systems are engineering facilities systems for treating and discharging urban rainwater and sewage, playing an indispensable role in improving the quality of life for urban residents and ensuring the stable development of cities. Rainwater and sewage pumping stations are an important component of urban drainage systems, solving problems such as rainwater and sewage in pipelines not being able to flow and discharge by gravity, and the need to pump rainwater and sewage before they can enter sewage treatment plants due to the large burial depth of pipelines or their location at the end of main pipelines.
[0003] During the design and construction of urban stormwater and sewage pumping stations, factors such as land area, geological conditions, and pipeline layout often result in compact inlet systems that cannot be arranged according to optimal flow conditions. Lateral arrangement is a common configuration, where the pumping station is vertically connected to the existing underground main drainage culvert via an inlet culvert. However, this lateral arrangement easily leads to backflow, deviation, and vortex phenomena in the inlet culvert, forebay, and intake pool. Furthermore, the high content of pollutants such as sludge in the transported stormwater and sewage can easily cause siltation in the pumping station's inlet system, especially in low-velocity areas. This not only blocks the flow path and affects the flow area but can also, in severe cases, jeopardize the operational safety and stability of the pumping station and the urban drainage system. In addition, dredging urban pipeline systems often relies on manual methods, which consumes significant manpower, resources, and funds, and also carries considerable risks. Summary of the Invention
[0004] The technical problem to be solved by the present invention is to address the shortcomings of the prior art by providing a method for reducing siltation in the inlet culvert of a laterally arranged stormwater and sewage drainage pumping station. This method can homogenize the flow rate of the inlet culvert and improve the uniformity of the flow velocity distribution, thereby improving the hydraulic flow state within the inlet culvert of the laterally arranged stormwater and sewage drainage pumping station. At the same time, it can collect the settled silt and achieve a hydraulic self-cleaning effect by relying on the flowing water, and discharge it in a timely manner. This effectively prevents siltation and blockage problems in the inlet culvert and drainage pumping station caused by silt in stormwater and sewage, while significantly reducing the cost of manual silt removal.
[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:
[0006] A method for reducing siltation in the inlet culvert of a laterally arranged stormwater and sewage drainage pumping station includes the following steps.
[0007] Step 1: Adjust the hydraulic flow state inside the inlet box culvert: The hydraulic flow state inside the inlet box culvert is adjusted by setting up a combination of partition walls and beam piers. The specific adjustment method includes the following steps.
[0008] Step 1-1, Lateral installation of inlet culvert: Connect the inlet end of the inlet culvert perpendicularly to the existing underground drainage main culvert, and install the pump station forebay and pump station intake pool coaxially at the outlet end of the inlet culvert.
[0009] Steps 1-2: Install partition walls: Install partition walls on the central axis of the inlet box culvert to divide the inlet box culvert into two equal openings, namely the left opening and the right opening; the water from the main box culvert enters the inlet box culvert evenly from the two openings.
[0010] Steps 1-3: Install beam-pier combination structures: Install a beam-pier combination structure at the inlet end of each of the two holes in Steps 1-2; wherein, the beam-pier combination structure installed in the left hole is a three-beam-pier combination, and the beam-pier combination structure installed in the right hole is a two-beam-pier combination.
[0011] The three-beam pier assembly consists of three crossbeams and three short piers; the two-beam pier assembly consists of two crossbeams and two short piers.
[0012] The crossbeams are arranged in parallel along the height direction of the corresponding hole, and each crossbeam is arranged along the width direction of the corresponding hole; the short piers are arranged in parallel along the width direction of the corresponding hole, and each short pier is arranged along the length direction of the corresponding hole, and the tail end of each short pier is flush with the backwater surface of all the crossbeams in the corresponding hole.
[0013] Step 2, silt reduction: At least one silt drainage ditch along the length direction is laid at the bottom center of each hole, and each silt drainage ditch is connected to a silt drainage pump through a pipeline; the silt drainage pump is used to reduce and transport the silt in the corresponding hole.
[0014] Inside the left hole, two short piers of the three-beam pier assembly are located on the left side of the drainage ditch inside the left hole, and the other short pier is located on the right side of the drainage ditch inside the left hole.
[0015] Let the width of the main box culvert be W and the height be H; the inlet width of the two openings of the inlet box culvert is W1, and the length of the inlet box culvert is L1 and L1≥2W1; the bottom surface of the two openings of the inlet box culvert is a slope with higher sides and lower middle in the width direction, the height of the side walls of the two openings of the box culvert is H1 and H1=H, and the slope of the two sides of the slope is i1 and i1=1:10~1:5; the length of the partition wall is L2 and L2=L1, the width is W2 and W2=(0.05~0.15)W1, and the height is H2 and H2=H1.
[0016] Each short pier in the three-beam pier assembly and the two-beam pier assembly has a length of L3 and L3 = (0.05~0.1)L1, and a width of W3 and W3 = (0.04~0.08)W1. Each short pier is connected to the top and bottom surfaces of the inflow box culvert in the height direction.
[0017] The three short piers in the three-beam pier assembly are, from left to right, left short pier one, middle short pier, and right short pier one; the distance between the left short pier and the left wall of the inlet box culvert is B1 and B1 = (0.1~0.15)W1; the distance between the middle short pier and left short pier one is B2 and B2 = (0.1~0.15)W1; the distance between right short pier one and the partition wall is B3 and B3 = (0.35~0.25)W1.
[0018] The two short piers in the two-beam pier assembly are the left short pier 2 and the right short pier 2; the distance between the left short pier 2 and the partition wall is B4 and B4 = (0.1~0.2)W1, and the distance between the right short pier 2 and the right wall of the inlet box culvert is B5 and B5 = (0.35~0.25)W1.
[0019] In both the three-beam pier assembly and the two-beam pier assembly, the length of each crossbeam is L4 and L4 = W1, the width of each crossbeam is W4 and W4 = (0.1~0.3)L3, and the thickness of each crossbeam is C1 and C1 = (0.08~0.2)H1.
[0020] The three crossbeams in the three-beam pier assembly, from bottom to top, are bottom crossbeam one, middle crossbeam, and top crossbeam one; the height of bottom crossbeam one from the bottom of the side wall is C2 and C2 = (0.2~0.3)H1, the distance between the middle crossbeam and bottom crossbeam one is C3 and C3 = (0.15~0.25)H1, and the distance between top crossbeam one and middle crossbeam one is C4 and C4 = (0.15~0.25)H1.
[0021] The two crossbeams in the two-beam pier assembly are, from bottom to top, bottom crossbeam two and top crossbeam two; the height of bottom crossbeam two from the bottom of the side wall is C5 and C5 = (0.2~0.3)H1, and the distance between top crossbeam two and bottom crossbeam two is C6 and C6 = (0.25~0.35)H1.
[0022] In step 2, the length of the drainage ditch in both holes is L5 and L5 = (0.9~0.98)L1, the width is W5 and W5 = (0.05~0.2)W1, the bottom surface of the drainage ditch is sloping with the inlet higher and the end lower. The distance between the bottom surface of the inlet of the drainage ditch and the bottom of the slope on both sides of the inflow box culvert is H3 and H3 = (0.1~0.2)H1, and the slope of the bottom surface of the drainage ditch is i2 and i2 = 1:50~1:20.
[0023] Each drainage ditch is equipped with a collection trough at its end. The length of the collection trough is L6, which satisfies L6 = L1 - L5; the width is W6, which satisfies W6 = W5; and the depth is H4, which satisfies H4 = (0.2 ~ 0.3)H1. The bottom of the collection trough is equipped with a drainage hole with a radius R that satisfies R = (0.2 ~ 0.3)D, where D = min(W6, L6). The collection trough is connected to the drainage pump through the drainage hole and further through a pipe.
[0024] In step 1-1, the total length of the pump station forebay and the pump station intake pool is L7, and L7 = (1.0~2.0)L1. The width of both the tail end of the pump station forebay and the pump station intake pool is W7, and W7 = (2.5~4)W1. The height of both the pump station forebay and the pump station intake pool is H5, and H5 = (2.0~3.0)H1. The height of the water surface from the bottom of the pump station forebay during pump station operation is H6, and H6 = (0.5~1.0)H5. The inlet section of the pump station forebay is a diffuser section with a slope, where the diffuser angle is β, and β = 30°~45°, and the slope is i3 = 1:4~1:3. The height between the bottom of the inlet culvert sidewall and the bottom of the pump station forebay is H7, and H7 = (0.4~0.6)L1. H1, the number of water pump units installed in the pump station intake pool is n and n = 3 to 5. The distance between the water pump units and the rear wall of the pump station intake pool is L8 and L8 = (0.08 to 0.15)L7. The distance between the water pump units on both sides and the side wall of the pump station intake pool connected to them is W8 and W8 = (0.1 to 0.2)W7. There is a partition between the connected water pump units. The length of the partition is L9 and L9 = (0.08 to 0.15)L7, and the width is W9 and W9 = (0.02 to 0.08)W7. The top and bottom of the partition are connected to the top and bottom surfaces of the intake pool in the height direction, respectively. The distance between adjacent water pump units is W10 and W10 = (W7 - 2 × W8) ÷ (n - 1).
[0025] The main culvert has a width W of 7m and a height H of 3.5m. The inlet width W1 of the two openings of the inlet culvert is 5m, and the length L1 of the inlet culvert is 13.5m. The sidewall height H1 of the two openings of the inlet culvert is 3.5m, and the slope i1 of both sides is 1:7. The partition wall has a length L2 of 13.5m, a width W2 of 0.5m, and a height H2 of 3.5m. The short pier at the front end of the inlet culvert has a length L3 of 0.7m and a width W3 of 0.2m. The distance B1 between the left short pier and the left side wall in the left opening of the inlet culvert is 0.6m, and the distance B2 between the middle short pier and the left short pier is 0. The distance between the right short pier 1 and the partition wall is B3, which is 1.65m. The distance between the left short pier 2 and the partition wall in the right opening of the inlet culvert is B4, which is 0.7m. The distance between the right short pier 2 and the right side wall is B5, which is 16.5m. The length of the crossbeam L4 is 5m, the width W4 is 0.2m, and the thickness C1 is 0.3m. The height of the bottom crossbeam 1 at the bottom of the left opening of the inlet culvert from the bottom of the side wall is C2, which is 1m. The distance between the middle crossbeam and the bottom crossbeam 1 is C3, which is 0.7m. The distance between the top crossbeam 1 and the middle crossbeam is C4, which is 0.7m. The height of the bottom crossbeam 2 at the bottom of the right opening of the inlet culvert from the bottom of the side wall is C5, which is 1m. The distance C6 between the top and bottom crossbeams is 1m; the length L5 of the drainage ditch is 12.7m and the width W5 is 0.8m; the distance H3 between the bottom surface of the drainage ditch inlet and the bottom of the slopes on both sides of the inlet culvert is 0.4m; the slope i2 of the bottom surface of the drainage ditch is 1:42; the length L6 of the collection trough is 0.8m, the width W6 is 0.8m, and the depth H4 is 0.7m; the radius R of the drainage hole at the bottom of the collection trough is 0.2m; the total length L7 of the stormwater and sewage drainage pumping station forebay and pumping station inlet pool is 19m; the width W7 of the pumping station forebay and pumping station inlet pool is 15m; the pumping station forebay and pumping station... The height H5 of the inlet pool is 8m. When the pump station is running, the height H6 of the water surface from the bottom of the forebay is 6.5m. The diffusion angle β of the inlet section of the forebay is 41° and the slope i3 is 1:4. The height H7 between the bottom of the side wall of the inlet culvert and the bottom of the forebay is 1.7m. The number of pump units n in the inlet pool is 3. The distance L8 between the pump unit and the rear side wall of the inlet pool is 2m. The distance W8 between the side pump unit and the side wall of the connected inlet pool is 2.2m. The length L9 of the spacer between connected pump units is 4m and the width W9 is 0.6m. The distance W10 between adjacent pump units is 5.3m.
[0026] It also includes step 3, evaluating the rectification and silt reduction effect, which specifically includes the following steps.
[0027] Step 3-1, Evaluation of Rectification Effect: j measuring points are set up at the outlet section of the inlet culvert, with at least one flow velocity monitoring device at each point; where j ≥ 3; the flow velocity monitored by the flow velocity monitoring device at the i-th measuring point at a set time is V. i If 1≤i≤j; then the uniformity of velocity distribution V at the outlet section of the inlet culvert. u The calculation formula is:
[0028]
[0029] In the formula, V is the average flow velocity at j measuring points.
[0030] The uniformity of velocity distribution before and after rectification, V u Comparative analysis was conducted to determine the uniformity of the flow velocity distribution, V. u The closer the value is to 100%, the more uniform the velocity distribution in the mainstream direction of the water flow at the outlet of the inlet culvert.
[0031] Step 3-2, Evaluation of silt reduction effect: Using M in M out Let represent the volume concentrations of sediment at the inlet of the culvert and the outlet of the pump unit, respectively. Then, the expression for calculating the sediment deposition rate ε is:
[0032] ε=(M in -M out ) / M in
[0033] A comparative analysis of the sediment deposition rate ε before and after rectification showed that the larger the sediment deposition rate ε, the more severe the siltation in the stormwater and sewage drainage pumping station.
[0034] The present invention has the following beneficial effects:
[0035] 1. The above-mentioned beam-pier combination measures can achieve the effect of homogenizing the flow rate of the inflow box culvert and improving the uniformity of the flow velocity distribution. It optimizes and adjusts the hydraulic flow state in the laterally arranged inflow box culvert, reduces the backflow zone and low velocity zone in the inflow box culvert, and thus effectively prevents the local siltation problem in the lateral inflow box culvert and improves the flow capacity of the inflow box culvert.
[0036] 2. The aforementioned inlet culvert features a sloping structure with higher sides and a lower middle in the width direction. A drainage ditch is also constructed in the middle of the inlet culvert to collect sludge and other sediments deposited in rainwater and wastewater. The drainage ditch's sloping design and reliance on the water flow from the inlet culvert enable hydraulic self-flushing, promptly transporting sediments to the collection tank. The drainage pump then discharges the sediments from the collection tank as needed, ultimately reducing sediment buildup in the inlet culvert and drainage pumping station caused by sludge and other sediments in rainwater and wastewater, thus improving the safety and stability of the rainwater and wastewater pumping station operation.
[0037] 3. The structural design adopted in this invention is simple and easy to construct and manufacture, and achieves the effect of hydraulic self-cleaning, effectively saving the cost of manual dredging. It is suitable for widespread use in the design and renovation of the inlet culvert of the side-arranged rainwater and sewage drainage pumping station. Attached Figure Description
[0038] Figure 1The diagram shows a plan view of the lateral arrangement of the stormwater and sewage drainage pumping station in this invention.
[0039] Figure 2 This diagram shows the planar structural dimensions of the laterally arranged stormwater and sewage drainage pumping station in this invention.
[0040] Figure 3 A schematic diagram of the inlet cross-sectional structure dimensions of the inlet box culvert in this invention is shown.
[0041] Figure 4 This diagram shows the elevation dimensions of a laterally arranged stormwater and sewage drainage pumping station according to the present invention.
[0042] Figure 5 The diagram shows a comparison of the uniformity of the flow velocity distribution at the outlet of the inlet culvert before and after rectification.
[0043] Figure 6 The diagram shows a comparison of the siltation rate before and after rectification of the lateral arrangement of the stormwater and sewage drainage pump station of the present invention.
[0044] These include: 1. Main box culvert; 2. Inlet box culvert; 2A. Left opening; 2B. Right opening; 3. Pump station forebay; 4. Pump station intake pool; 5. Pump unit; 6. Partition wall;
[0045] 7. Left arch short pier; 7A. Left side short pier one; 7B. Middle short pier; 7C. Right side short pier one;
[0046] 8. Left crossbeam; 8A. Bottom crossbeam one; 8B. Middle crossbeam; 8C. Top crossbeam one;
[0047] 9. Right-hand short pier; 9A. Left-hand short pier two; 9B. Right-hand short pier two;
[0048] 10. Right-hand crossbeam; 10A. Bottom crossbeam two; 10B. Top crossbeam two;
[0049] 11. Dredging ditch; 11A. Left drain ditch; 11B. Right drain ditch;
[0050] 12. Collection tank; 13. Sludge discharge pipe; 14. Divider; 15. Sludge discharge pump. Detailed Implementation
[0051] The present invention will now be described in further detail with reference to the accompanying drawings and specific preferred embodiments.
[0052] In the description of this invention, it should be understood that the terms "left side," "right side," "upper part," "lower part," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. "First," "second," etc., do not indicate the importance of the components, and therefore should not be construed as a limitation of this invention. The specific dimensions used in this embodiment are only for illustrating the technical solution and do not limit the scope of protection of this invention.
[0053] A method for reducing siltation in the inlet culvert of a laterally arranged stormwater and sewage drainage pumping station includes the following steps.
[0054] Step 1: Adjust the hydraulic flow pattern inside the inlet culvert: such as Figures 1 to 4 As shown, the hydraulic flow state within the inflow box culvert is adjusted by setting up a combination of partition walls and beam piers inside the culvert. The specific adjustment method includes the following steps.
[0055] Step 1-1, Lateral installation of inlet culvert: Connect the inlet end of the inlet culvert perpendicularly to the existing underground drainage main culvert, and install the pump station forebay and pump station intake pool coaxially at the outlet end of the inlet culvert.
[0056] The width of the main box culvert 1 is W and the height is H.
[0057] The inlet box culvert 2 is a double-hole structure separated by a partition wall 6. The inlet width of both holes of the inlet box culvert 2 is W1, the length of the inlet box culvert 2 is L1 and L1≥2W1, the bottom surface of the two holes of the inlet box culvert 2 is a slope with higher sides and lower middle in the width direction, the height of the side walls on both sides of the two-hole box culvert is H1 and H1=H, and the slope of both sides is i1 and i1=1:10~1:5.
[0058] The outlet of the inlet culvert 2 connects to the inlet of the forebay 3 of the stormwater and sewage drainage pumping station. The total length of the forebay 3 and the inlet pool 4 is L7, and L7 = (1.0~2.0)L1. The width of both the forebay 3 and the inlet pool 4 is W7, and W7 = (2.5~4)W1. The height of the forebay 3 and the inlet pool 4 is H5, and H5 = (2.0~3.0)H1. When the pumping station is running, the water surface is at a height of H6 from the bottom of the forebay 3, and H6 = (0.5~1.0)H5. The inlet section of the forebay 3 is a diffuser section with a slope, where the diffuser angle is β, and β = 30°~45°, and the slope is i3 = 1:4~1:3. The height between the bottom of the sidewall of the inlet culvert 2 and the bottom of the forebay 3 is H7, and H7 = (0.5~1.0)H5. 0.4~0.6)H1, the number of water pump units 5 installed in the water inlet pool 4 of the pump station is n and n=3~5, the distance between the water pump unit 5 and the rear wall of the water inlet pool 4 is L8 and L8=(0.08~0.15)L7, the distance between the water pump unit 5 on both sides and the side wall of the water inlet pool 4 connected to it is W8 and W8=(0.1~0.2)W7, there is a partition 14 between the connected water pumps, the length of the partition 14 is L9 and L9=(0.08~0.15)L7, the width is W9 and W9=(0.02~0.08)W7, the top and bottom of the partition 14 are connected to the top and bottom surfaces of the water inlet pool 4 respectively in the height direction, and the distance between adjacent water pumps is W10 and W10=(W7-2×W8)÷(n-1).
[0059] Step 1-2: Install partition walls: Install partition walls 6 on the central axis of the inlet box culvert to divide the inlet box culvert into two equal openings, namely the left opening 2A and the right opening 2B; the water from the main box culvert enters the inlet box culvert evenly from the two openings.
[0060] The preferred length of the partition wall 6 is L2 and L2 = L1, the width is W2 and W2 = (0.05~0.15)W1, and the height is H2 and H2 = H1.
[0061] Steps 1-3: Laying out the beam-pier combination structure
[0062] A beam-pier combination system is installed at the front end of the inflow box culvert 2. The left culvert 2A uses a "three short piers + three crossbeams" scheme, while the right culvert 2B uses a "two short piers + two crossbeams" scheme. That is, the beam-pier combination structure in the left culvert is a three-beam-pier assembly, and the beam-pier combination structure in the right culvert is a two-beam-pier assembly. The three-beam-pier assembly includes three crossbeams and three short piers; the two-beam-pier assembly includes two crossbeams and two short piers.
[0063] Because the inflow box culvert is arranged laterally, the water flow in the main box culvert needs to turn 90 degrees to enter the inflow box culvert. Of the two openings, the left opening (i.e., the outer opening) will have more inflow. In this invention, a three-beam pier assembly is set in the left opening and a two-beam pier assembly is set in the right opening. That is, an additional pair of crossbeams and short piers are added to the left opening to increase water resistance and allow the water flow to enter the right box culvert opening from more points, thereby balancing the water flow in the two openings.
[0064] The front ends of each short pier are located on the inlet section of the inlet box culvert 2. The horizontal cross-sectional structural dimensions of each short pier are the same. The length of short piers 7 and 9 is L3, where L3 = (0.05~0.1)L1, and the width is W3, where W3 = (0.04~0.08)W1. Each short pier connects to the top and bottom surfaces of the inlet box culvert in the height direction. The distance between the left short pier 7A in the left opening 2A of the inlet box culvert and the left side wall is B1, where B1 = (0.1~0.15)W1. The distance between the middle short pier 7B and the left side wall is... The spacing between short pier 1 7A and partition wall 6 is B2, where B2 = (0.1~0.15)W1; the spacing between right short pier 1 7C and partition wall 6 is B3, where B3 = (0.35~0.25)W1; the spacing between left short pier 2 9A and partition wall 6 in right hole 2B is B4, where B4 = (0.1~0.2)W1; the spacing between right short pier 2 9B and right wall is B5, where B5 = (0.35~0.25)W1. All crossbeams have the same structural dimensions, and the lengths of crossbeams 8 and 10 are L4, where L4 = W1. That is, the two ends of crossbeams 8 and 10 are horizontally connected to the side walls of the inlet culvert openings, respectively. The backwater surfaces of crossbeams 8 and 10 are flush with the tails of short piers 7 and 9, respectively. The width of crossbeams 8 and 10 is W4, where W4 = (0.1~0.3)L3, and the thickness of crossbeams 8 and 10 is C1, where C1 = (0.08~0.2)H1. The bottom crossbeam 8A of the three crossbeams in the left opening 2A of the inlet culvert is C2, where C2 = (0.2~0.3)H1, and the middle crossbeam... The distance between beam 8B and bottom crossbeam 8A is C3 and C3 = (0.15~0.25)H1; the distance between top crossbeam 8C and middle crossbeam 8B is C4 and C4 = (0.15~0.25)H1; the height of bottom crossbeam 10A of the two crossbeams in the right opening 2B of the inlet culvert from the bottom of the sidewall is C5 and C5 = (0.2~0.3)H1; the distance between top crossbeam 10B and bottom crossbeam 10A is C6 and C6 = (0.25~0.35)H1.
[0065] Step 2, silt reduction: At least one silt drainage ditch along the length direction is laid at the bottom center of each hole, and each silt drainage ditch is connected to a silt drainage pump through a pipeline; the silt drainage pump is used to reduce and transport the silt in the corresponding hole.
[0066] Inside the left hole, two short piers of the three-beam pier assembly are located on the left side of the drainage ditch inside the left hole, and the other short pier is located on the right side of the drainage ditch inside the left hole.
[0067] A drainage ditch 11A and a drainage ditch 11B are installed in the middle of each of the two openings of the inlet culvert 2. The length of the drainage ditch 11 is L5, where L5 = (0.9~0.98)L1, and the width is W5, where W5 = (0.05~0.2)W1. The bottom surface of the drainage ditch 11 is sloping, with its inlet higher than its end. The distance between the bottom surface of the inlet of the drainage ditch 11 and the bottom of the slopes on both sides of the inlet culvert 2 is H3, where H3 = (0.1~0.2)H1. The slope of the bottom surface of the drainage ditch 11 is i2, where i2 = 1:50~1:1. :20, a collection trough 12 is provided at the end of the silt drainage ditch 11. The length of the collection trough 12 is L6 and it satisfies L6=L1-L5, the width is W6 and W6=W5, and the depth is H4 and H4=(0.2~0.3)H1. The bottom of the collection trough 12 is provided with a silt drainage hole and its radius R satisfies R=(0.2~0.3)D, where D=min(W6,L6). The collection trough 12 is connected to the silt drainage pump 15 through the silt drainage hole and further through the pipe 13. The silt drainage pump is used to transport the silt.
[0068] The effects of implementing the present invention will be described in detail below with reference to specific embodiments.
[0069] Example
[0070] The main box culvert 1 has a width W of 7m and a height H of 3.5m. The inlet width W1 of the two openings of the inlet box culvert 2 is 5m, and the length L1 of the inlet box culvert 2 is 13.5m. The height H1 of the sidewalls of the two openings of the inlet box culvert 2 is 3.5m, and the slope i1 of both sides is 1:7. The partition wall 6 has a length L2 of 13.5m, a width W2 of 0.5m, and a height H2 of 3.5m. The short piers 7 and 9 at the front end of the inlet box culvert 2 have a length L3 of 0.7m and a width W3 of 0.2m. The distance B1 between the left short pier 7A and the left side wall in the left opening 2A of the inlet box culvert is 0.6m, and the distance B2 between the middle short pier 7B and the left short pier 7A is... The distance between the right short pier 7C and the partition wall is 1.65m. In the right opening 2B of the inflow culvert, the distance between the left short pier 9A and the partition wall is 0.7m, and the distance between the right short pier 9B and the right side wall is 16.5m. The length L4 of crossbeams 8 and 10 is 5m, the thickness W4 is 0.2m, and the width C1 is 0.3m. The distance C2 between the bottom crossbeam 8A of the left opening 2A of the inflow culvert and the bottom of the side wall is 1m. The distance C3 between the middle crossbeam 8B and the bottom crossbeam 8A is 0.7m, and the distance C4 between the top crossbeam 8C and the middle crossbeam 8B is 0.7m. The distance between the bottom crossbeam 10A of the right opening 2B of the inflow culvert is... The height C5 from the bottom of the side wall is 1m; the distance C6 between the top crossbeam 10B and the bottom crossbeam 10B is 1m; the length L5 of the drainage ditch 11 is 12.7m and the width W5 is 0.8m; the distance H3 between the bottom surface of the inlet of the drainage ditch 11 and the bottom of the slopes on both sides of the inlet culvert 2 is 0.4m; the slope i2 of the bottom surface of the drainage ditch 11 is 1:42; the length L6 of the collection tank 12 is 0.8m, the width W6 is 0.8m, and the depth H4 is 0.7m; the radius R of the drainage hole at the bottom of the collection tank 12 is 0.2m; the total length L7 of the forebay 3 and the inlet pool 4 of the stormwater and sewage drainage pumping station is 19m; and the width W7 of the forebay 3 and the inlet pool 4 is 1m. The height H5 of the forebay 3 and the inlet pool 4 is 8m. When the pump station is running, the height H6 of the water surface from the bottom of the forebay 3 is 6.5m. The diffusion angle β of the inlet section of the forebay 3 is 41° and the slope i3 is 1:4. The height H7 between the bottom of the side wall of the inlet culvert 2 and the bottom of the forebay 3 is 1.7m. The number n of the pump units 5 in the inlet pool 4 is 3. The distance L8 between the pump unit 5 and the rear side wall of the inlet pool 4 is 2m. The distance W8 between the pump unit 5 and the side wall of the connected inlet pool 4 is 2.2m. The length L9 of the spacer 14 between the connected pumps is 4m and the width W9 is 0.6m. The distance W10 between adjacent pumps is 5.3m.
[0071] Step 3, Evaluation of the rectification and silt reduction effect, specifically includes the following steps.
[0072] Step 3-1, Evaluation of Rectification Effect: j measuring points are set up at the outlet section of the inlet culvert, with at least one flow velocity monitoring device at each point; where j ≥ 3; the flow velocity monitored by the flow velocity monitoring device at the i-th measuring point at a set time is V. iIf 1≤i≤j; then the uniformity of velocity distribution V at the outlet section of the inlet culvert. u The calculation formula is:
[0073]
[0074] In the formula, V is the average flow velocity at j measuring points.
[0075] The uniformity of velocity distribution before and after rectification, V u Comparative analysis was conducted to determine the uniformity of the flow velocity distribution, V. u The closer the value is to 100%, the more uniform the velocity distribution in the mainstream direction of the water flow at the outlet of the inlet culvert.
[0076] Step 3-2, Evaluation of silt reduction effect: Using M in M out Let represent the volume concentrations of sediment at the inlet of the culvert and the outlet of the pump unit, respectively. Then, the expression for calculating the sediment deposition rate ε is:
[0077] ε=(M in -M out ) / M in
[0078] A comparative analysis of the sediment deposition rate ε before and after rectification showed that the larger the sediment deposition rate ε, the more severe the siltation in the stormwater and sewage drainage pumping station.
[0079] like Figure 5 , 6 As shown, a three-dimensional flow numerical simulation method is used to compare and analyze the uniformity of flow velocity distribution and sediment deposition efficiency of the lateral arrangement stormwater and sewage drainage pumping station in the above embodiment of the present invention before and after rectification.
[0080] according to Figure 5 , Figure 6 It can be seen that the uniformity of the flow velocity distribution at the inlet culvert outlet of the lateral arrangement stormwater and sewage drainage pumping station after rectification by the present invention is V. u The results are significantly improved, and the sediment deposition rate ε in the pumping station is greatly reduced, proving that the present invention can significantly improve the hydraulic flow state in the inlet culvert of the laterally arranged stormwater and sewage pumping station and achieve the silt reduction effect, which helps to ensure the safety and stability of the operation of the stormwater and sewage pumping station.
[0081] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various equivalent transformations can be made to the technical solutions of the present invention, and these equivalent transformations all fall within the protection scope of the present invention.
Claims
1. A method for reducing siltation in the inlet culvert of a laterally arranged stormwater and sewage drainage pumping station, characterized in that: The steps include the following: Step 1: Adjusting the hydraulic flow pattern within the inlet box culvert: The hydraulic flow pattern within the inlet box culvert is adjusted by installing a combination of partition walls and beam piers. The specific adjustment method includes the following steps: Step 1-1, Lateral installation of inlet box culvert: Connect the inlet end of the inlet box culvert perpendicularly to the existing underground drainage main box culvert, and install the pump station forebay and pump station intake pool coaxially at the outlet end of the inlet box culvert. Steps 1-2: Install partition walls: Install partition walls on the central axis of the inlet box culvert to divide the inlet box culvert into two equal openings, namely the left opening and the right opening; the water from the main box culvert enters the inlet box culvert evenly from the two openings. Let the width of the main box culvert be W and the height be H; the inlet width of both openings of the inlet box culvert is W1, and the length of the inlet box culvert is L1 and L1≥2W1; the bottom surface of the two openings of the inlet box culvert is a slope with higher sides and lower middle in the width direction. Steps 1-3: Install beam-pier combination structures: Install a beam-pier combination structure at the inlet end of each of the two holes in Steps 1-2; wherein, the beam-pier combination structure installed in the left hole is a three-beam-pier combination, and the beam-pier combination structure installed in the right hole is a two-beam-pier combination. The three-beam pier assembly includes three crossbeams and three short piers; the three short piers, from left to right, are left short pier one, middle short pier, and right short pier one; the distance between the left short pier and the left wall of the inlet box culvert is B1 and B1 = (0.1~0.15)W1; the distance between the middle short pier and left short pier one is B2 and B2 = (0.1~0.15)W1; the distance between right short pier one and the partition wall is B3 and B3 = (0.35~0.25)W1; The two-beam pier assembly includes two crossbeams and two short piers; the two short piers are left short pier two and right short pier two; the distance between left short pier two and the partition wall is B4 and B4 = (0.1~0.2)W1, and the distance between right short pier two and the right wall of the inlet box culvert is B5 and B5 = (0.35~0.25)W1; The crossbeams are arranged in parallel along the height direction of the corresponding hole, and each crossbeam is arranged along the width direction of the corresponding hole; the short piers are arranged in parallel along the width direction of the corresponding hole, and each short pier is arranged along the length direction of the corresponding hole, and the tail end of each short pier is flush with the backwater surface of all the crossbeams in the corresponding hole. The beam-pier combination can equalize the flow rate of the inflow box culvert and improve the uniformity of the flow velocity distribution. It optimizes and adjusts the hydraulic flow state in the laterally arranged inflow box culvert, reduces the backflow zone and low velocity zone in the inflow box culvert, and thus effectively prevents the local siltation problem in the lateral inflow box culvert and improves the flow capacity of the inflow box culvert. Step 2, silt reduction: At least one silt drainage ditch along the length direction is laid at the bottom center of each hole, and each silt drainage ditch is connected to a silt drainage pump through a pipeline; the silt drainage pump is used to reduce and transport the silt in the corresponding hole.
2. The method for reducing siltation in the inlet culvert of a laterally arranged stormwater and sewage drainage pumping station according to claim 1, characterized in that: Inside the left hole, two short piers of the three-beam pier assembly are located on the left side of the drainage ditch inside the left hole, and the other short pier is located on the right side of the drainage ditch inside the left hole.
3. The method for reducing siltation in the inlet culvert of a laterally arranged stormwater and sewage drainage pumping station according to claim 2, characterized in that: The height of the two-span box culvert sidewalls is H1 and H1=H, the slope of the two slopes is i1 and i1=1:10~1:5; the length of the partition wall is L2 and L2=L1, the width is W2 and W2=(0.05~0.15)W1, and the height is H2 and H2=H1.
4. The method for reducing siltation in the inlet culvert of a laterally arranged stormwater and sewage drainage pumping station according to claim 3, characterized in that: Each short pier in the three-beam pier assembly and the two-beam pier assembly has a length of L3 and L3 = (0.05~0.1)L1, and a width of W3 and W3 = (0.04~0.08)W1. Each short pier is connected to the top and bottom surfaces of the inflow box culvert in the height direction.
5. The method for reducing siltation in the inlet culvert of a laterally arranged stormwater and sewage drainage pumping station according to claim 4, characterized in that: In both the three-beam pier assembly and the two-beam pier assembly, the length of each crossbeam is L4 and L4=W1, the width of each crossbeam is W4 and W4=(0.1~0.3)L3, and the thickness of each crossbeam is C1 and C1=(0.08~0.2)H1. The three horizontal beams in the three-beam pier assembly, from bottom to top, are bottom horizontal beam one, middle horizontal beam and top horizontal beam one; the height of bottom horizontal beam one from the bottom of the side wall is C2 and C2 = (0.2~0.3)H1, the distance between the middle horizontal beam and bottom horizontal beam one is C3 and C3 = (0.15~0.25)H1, and the distance between top horizontal beam one and middle horizontal beam one is C4 and C4 = (0.15~0.25)H1; The two crossbeams in the two-beam pier assembly are, from bottom to top, the bottom crossbeam two and the top crossbeam two; the height of the bottom crossbeam two from the bottom of the side wall is C5 and C5 = (0.2~0.3)H1, and the distance between the top crossbeam two and the bottom crossbeam two is C6 and C6 = (0.25~0.35)H1.
6. The method for reducing siltation in the inlet culvert of a laterally arranged stormwater and sewage drainage pumping station according to claim 5, characterized in that: In step 2, the length of the drainage ditch in both holes is L5 and L5 = (0.9~0.98)L1, the width is W5 and W5 = (0.05~0.2)W1, the bottom surface of the drainage ditch is sloping with the inlet higher and the end lower, the distance between the bottom surface of the inlet of the drainage ditch and the bottom of the slope on both sides of the inflow box culvert is H3 and H3 = (0.1~0.2)H1, and the slope of the bottom surface of the drainage ditch is i2 and i2 = 1:50~1:
20.
7. The method for reducing siltation in the inlet culvert of a laterally arranged stormwater and sewage drainage pumping station according to claim 6, characterized in that: Each drainage ditch is equipped with a collection trough at its end. The length of the collection trough is L6 and it satisfies L6=L1-L5, the width is W6 and it satisfies W6=W5, and the depth is H4 and it satisfies H4=(0.2~0.3)H1. The bottom of the collection trough is equipped with a drainage hole and its radius R satisfies R=(0.2~0.3)D, where D=min(W6,L6). The collection trough is connected to the drainage pump through the drainage hole and further through a pipe.
8. The method for reducing siltation in the inlet culvert of a laterally arranged stormwater and sewage drainage pumping station according to claim 1, characterized in that: In step 1-1, the total length of the pump station forebay and the pump station intake pool is L7, and L7 = (1.0~2.0)L1. The width of both the tail end of the pump station forebay and the pump station intake pool is W7, and W7 = (2.5~4)W1. The height of both the pump station forebay and the pump station intake pool is H5, and H5 = (2.0~3.0)H1. The height of the water surface from the bottom of the pump station forebay during pump station operation is H6, and H6 = (0.5~1.0)H5. The inlet section of the pump station forebay is a diffuser section with a slope, where the diffuser angle is β, and β = 30°~45°, and the slope is i3 = 1:4~1:
3. The height between the bottom of the inlet culvert sidewall and the bottom of the pump station forebay is H7, and H7 = (0.4~0.6)L1. H1, the number of water pump units installed in the pump station intake pool is n and n=3~5. The distance between the water pump units and the rear wall of the pump station intake pool is L8 and L8=(0.08~0.15)L7. The distance between the water pump units on both sides and the side wall of the pump station intake pool connected to them is W8 and W8=(0.1~0.2)W7. There is a partition between the connected water pump units. The length of the partition is L9 and L9=(0.08~0.15)L7, and the width is W9 and W9=(0.02~0.08)W7. The top and bottom of the partition are connected to the top and bottom surfaces of the intake pool in the height direction, respectively. The distance between adjacent water pump units is W10 and W10=(W7-2×W8)÷(n-1).
9. The method for reducing siltation in the inlet culvert of a laterally arranged stormwater and sewage drainage pumping station according to claim 8, characterized in that: The main culvert has a width W of 7m and a height H of 3.5m. The inlet width W1 of the two openings of the inlet culvert is 5m, and the length L1 of the inlet culvert is 13.5m. The sidewall height H1 of the two openings of the inlet culvert is 3.5m, and the slope i1 of both sides is 1:
7. The partition wall has a length L2 of 13.5m, a width W2 of 0.5m, and a height H2 of 3.5m. The short pier at the front end of the inlet culvert has a length L3 of 0.7m and a width W3 of 0.2m. The distance B1 between the left short pier and the left side wall in the left opening of the inlet culvert is 0.6m, and the distance B2 between the middle short pier and the left short pier is 0. The distance between the right short pier 1 and the partition wall is B3, which is 1.65m. The distance between the left short pier 2 and the partition wall in the right opening of the inlet culvert is B4, which is 0.7m. The distance between the right short pier 2 and the right side wall is B5, which is 16.5m. The length of the crossbeam L4 is 5m, the width W4 is 0.2m, and the thickness C1 is 0.3m. The height of the bottom crossbeam 1 at the bottom of the left opening of the inlet culvert from the bottom of the side wall is C2, which is 1m. The distance between the middle crossbeam and the bottom crossbeam 1 is C3, which is 0.7m. The distance between the top crossbeam 1 and the middle crossbeam is C4, which is 0.7m. The height of the bottom crossbeam 2 at the bottom of the right opening of the inlet culvert from the bottom of the side wall is C5, which is 1m. The distance C6 between the top and bottom crossbeams is 1m; the length L5 of the drainage ditch is 12.7m and the width W5 is 0.8m; the distance H3 between the bottom surface of the drainage ditch inlet and the bottom of the slopes on both sides of the inlet culvert is 0.4m; the slope i2 of the bottom surface of the drainage ditch is 1:42; the length L6 of the collection trough is 0.8m, the width W6 is 0.8m, and the depth H4 is 0.7m; the radius R of the drainage hole at the bottom of the collection trough is 0.2m; the total length L7 of the stormwater and sewage drainage pumping station forebay and pumping station inlet pool is 19m; the width W7 of the pumping station forebay and pumping station inlet pool is 15m; the pumping station forebay and pumping station... The height H5 of the inlet pool is 8m. When the pump station is running, the height H6 of the water surface from the bottom of the forebay is 6.5m. The diffusion angle β of the inlet section of the forebay is 41° and the slope i3 is 1:
4. The height H7 between the bottom of the side wall of the inlet culvert and the bottom of the forebay is 1.7m. The number of pump units n in the inlet pool is 3. The distance L8 between the pump unit and the rear side wall of the inlet pool is 2m. The distance W8 between the side pump unit and the side wall of the connected inlet pool is 2.2m. The length L9 of the spacer between connected pump units is 4m and the width W9 is 0.6m. The distance W10 between adjacent pump units is 5.3m.
10. The method for reducing siltation in the inlet culvert of a laterally arranged stormwater and sewage drainage pumping station according to claim 1, characterized in that: It also includes step 3, evaluating the rectification and silt reduction effect, which specifically includes the following steps: Step 3-1, Evaluation of Rectification Effect: j measuring points are set up at the outlet section of the inlet culvert, with at least one flow velocity monitoring device at each point; where j ≥ 3; the flow velocity monitored by the flow velocity monitoring device at the i-th measuring point at a set time is... If 1≤i≤j, then the uniformity of velocity distribution at the outlet section of the inlet culvert is... The calculation formula is: ； In the formula, Let be the average value of the flow velocity at j measurement points; Uniformity of velocity distribution before and after rectification Comparative analysis was conducted to determine the uniformity of the flow velocity distribution, V. u The closer the value is to 100%, the more uniform the velocity distribution in the mainstream direction of the water flow at the outlet of the inlet culvert. Step 3-2, Evaluation of silt reduction effect: Using M in M out Let represent the volume concentrations of sediment at the inlet of the culvert and the outlet of the pump unit, respectively. Then, the expression for calculating the sediment deposition rate ε is: ； A comparative analysis of the sediment deposition rate ε before and after rectification showed that the larger the sediment deposition rate ε, the more severe the siltation in the stormwater and sewage drainage pumping station.