Pressure forebay of booster pump station

Abstract

The utility model discloses a pressure forebay of a booster pump station, which belongs to the technical field of pressure forebays, is communicated with an outlet end of a communicated culvert and comprises a forebay body, and the forebay body comprises a bottom plate, a top plate, side walls and beams. The side wall of the tank body adopts a quartic curve type boundary; a plurality of upright posts are arranged in the tank body, and nine rows of upright posts are arranged according to the shape structure of the tank body; the outlet end of the tank body is communicated with flared tubes, and the last row of upright posts are positioned between the axes of the adjacent flared tubes. According to the utility model, the problem of a large-range backflow area caused by an overlarge divergence angle of the pressure forebay is successfully solved, the average values of the flow velocity distribution uniformity and the water flow angle of the outlet of the flare tube in each working condition are not less than 98% and 87 degrees, and necessary conditions are provided for ensuring the normal operation of a water pump unit.

Description

Technical Field

[0001] The utility model relates to the technical field of pressure forebays, in particular to a pressure forebay of a booster pump station. Background Art

[0002] The pressure forepool refers to a pool that connects the non-pressure water diversion channel and the pressure pipe, and is used to regulate the water volume and water level for the turbine and stabilize the water flow. It is located at the junction of the non-pressure water diversion channel and the pressure pipe of the hydropower station, and is equipped with facilities such as removing debris and discharging abandoned water. It consists of a pool body, pressure wall, pressure pipe water inlet, spillway, sewage discharge, sand discharge, ice discharge channel, etc. The various buildings are set up as needed, and some buildings can be used in combination, such as sewage discharge, ice discharge and sand discharge channels can share a steep trough.

[0003] The pressure forebay must be able to accommodate a certain volume of water, and it should be widened and deepened by making use of favorable terrain. However, some areas are limited by the size of the site layout. The diffusion angle of the pressure forebay of the engineering booster pump station can reach 78.8°, which greatly exceeds the normal diffusion angle of the forebay. The mainstream in the pressure forebay is concentrated in the middle area along the center line of the forebay, and a large-scale backflow area is formed on both sides due to wall shedding. The water flows to the trumpet pipes of each water pump at different turning angles. The farther the pump is from the center line of the pressure forebay, the greater the water deflection angle. Utility Model Content

[0004] In view of the above-mentioned deficiencies in the prior art, the present invention provides a pressure forebay of a booster pump station; the pressure forebay of a booster pump station satisfactorily solves the problem of a large-scale reflux area caused by an excessively large diffusion angle in the pressure forebay, and the average values ​​of the flow velocity distribution uniformity and the water flow angle at the outlet of the trumpet in each working condition are not less than 98% and 87°, respectively, thereby providing the necessary conditions for ensuring the normal operation of the water pump unit.

[0005] In order to solve the above technical problems, the utility model provides a pressure forepool of a booster pump station, which is connected to the outlet end of a connected culvert, and includes a pool body, wherein the pool body includes a bottom plate, a top plate, side walls and beams; the side walls of the pool body adopt a quadratic curved boundary; a plurality of columns are arranged in the pool body, and the columns are arranged in nine rows according to the shape and structure of the pool body; the outlet end of the pool body is connected to a trumpet pipe, and the last row of columns is located in the middle of the axis of adjacent trumpet pipes.

[0006] In a further improvement of the present invention, the first row is provided with two columns, the second row is provided with two columns, the third to sixth rows are provided with one column in sequence, the seventh row is provided with eight columns, the eighth row is provided with six columns, and the ninth row is provided with seven columns; the distance between adjacent rows from the first row to the seventh row is equal, and the distance between the seventh row to the ninth row decreases.

[0007] Through the above design, this solution can be more convenient for column arrangement.

[0008] In a further improvement of the present invention, the columns in each row are evenly arranged.

[0009] Through the above design, this solution can more easily buffer the water flow.

[0010] In a further improvement of the present invention, the trumpet pipe is connected to a water pump inlet pipe.

[0011] Through the above design, this solution can make it easier for water to flow into the water pump.

[0012] In a further improvement of the present invention, the positions of the columns and the beams correspond one to one.

[0013] Through the above design, this solution can more easily meet the requirements of column structure strength and top plate deformation.

[0014] In a further improvement of the present invention, the inlet end and the outlet end of the pool body are respectively provided with manholes.

[0015] Through the above design, this solution can make it easier to control the pool body.

[0016] In a further improvement of the present invention, the middle pier at the outlet of the connecting culvert extends 2m into the pool body to form a diversion wall.

[0017] Through the above design, this solution can more easily shorten the length of the forebay in the downstream direction, optimize water flow conditions, and save floor space and project investment.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The utility model satisfactorily solves the problem of a large-scale reflux zone in the pressure forebay due to an excessively large diffusion angle. The average values ​​of the flow velocity distribution uniformity and the water flow angle at the trumpet outlet in each working condition are not less than 98% and 87°, respectively, thus providing the necessary conditions for ensuring the normal operation of the water pump unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the background technology or the technical solution of the present invention, the following is a brief introduction to the drawings used in conjunction with the prior art or specific implementation methods; it is obvious that the structures, proportions, sizes, etc. illustrated in the drawings of the specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the conditions under which the present invention can be implemented, so they have no technical significance. Any structural modification, change in proportional relationship or adjustment of size should still fall within the scope of the technical content disclosed in the present invention without affecting the efficacy and purpose that can be achieved by the present invention.

[0021] Figure 1 It is a plan view of a specific implementation method of the utility model.

[0022] Figure 2 It is a longitudinal sectional view of a specific embodiment of the present utility model.

[0023] Figure 3 This is the flow field diagram of working condition 1 of the specific implementation method of the utility model.

[0024] Figure 4 This is the flow field diagram of working condition 2 of the specific implementation method of the utility model.

[0025] Figure 5 This is the flow field diagram of working condition 3 of the specific implementation method of the utility model.

[0026] Figure 6 This is the flow field diagram of working condition 4 of the specific implementation method of the utility model.

[0027] Figure 7 This is the flow field diagram of working condition 5 of the specific implementation method of the utility model.

[0028] Figure 8 This is a vertical stress cloud diagram of the column array according to a specific embodiment of the present invention.

[0029] Figure 9 This is a cloud diagram of the vertical deformation of the structure of a specific implementation method of the utility model.

[0030] As shown in the figure: 1. Pool body; 2. Bottom plate; 3. Top plate; 4. Side wall; 5. Beam; 6. Column; 7. Trumpet pipe; 8. Water pump inlet pipe; 9. Manhole. DETAILED DESCRIPTION

[0031] In order to enable people skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work should fall within the scope of protection of the present invention.

[0032] At the same time, the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like cited in this specification indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention. Changes or adjustments to their relative relationships, without substantially changing the technical content, should also be regarded as the scope of implementation of the present invention.

[0033] At the same time, in the description of this specification, it should be noted that, unless otherwise clearly stipulated and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be a connection between the internal parts of two components. For ordinary technicians in this field, the specific meanings of the above terms in this utility model can be understood according to specific circumstances.

[0034] In some areas, due to the limitations of site layout size, the diffusion angle of the pressure forebay of the engineering booster pump station can reach 78.8°, which greatly exceeds the normal diffusion angle of the forebay. The mainstream in the pressure forebay is concentrated in the middle area along the centerline of the forebay, and large-scale backflow areas are formed on both sides due to wall shedding. The water flows to the bell pipes of each water pump at different turning angles. The farther the pump is from the centerline of the pressure forebay, the greater the water flow deflection angle.

[0035] Therefore, the design concept of this application is to optimize the column array and the side wall profile of the forebay to give full play to the overall effect of the column array in rectifying the water flow.

[0036] like Figure 1-2 As shown, the present application provides a pressure forepool of a booster pump station, which is connected to the outlet end of a connected culvert, and includes a tank body 1, wherein the tank body 1 includes a bottom plate 2, a top plate 3, a side wall 4 and a beam 5; the side wall 4 of the tank body adopts a quadratic curved boundary; a plurality of columns 6 are arranged in the tank body 1, and the columns 6 are arranged in nine rows according to the shape structure of the tank body 1 (the "rows" in this article are shown as vertical rows in the drawings of the specification); the outlet end of the tank body 1 is connected to a trumpet pipe 7, and each column 6 in the last row is located in the middle of the axis of the adjacent trumpet pipe 7.

[0037] This application utilizes dozens of structural support columns in the pressure forebay of the pump station. Under the condition that the size of the pressure forebay remains unchanged, a technical solution of coordinating the arrangement of columns with the adjustment of the boundary profile of the side wall of the forebay is adopted to conduct a forebay rectification optimization study. This solves the large-scale backflow area and turbulent flow near the trumpet pipe in the pressure forebay of the pump station caused by the excessive diffusion angle, and provides the necessary conditions for the safe and stable operation of the water pump. This application is applicable to all types of pressure forebays, can improve the flow state of the water in the forebay, and save the area occupied by the forebay and engineering investment.

[0038] Among them, the first row is provided with two columns 6, the second row is provided with two columns 6, the third row to the sixth row are provided with one column 6 in sequence, the seventh row is provided with eight columns 6, the eighth row is provided with six columns 6, and the ninth row is provided with seven columns 6; the distance between adjacent rows from the first row to the seventh row is equal, and the distance between the rows from the seventh row to the ninth row decreases; wherein, the columns 6 in each row are evenly arranged.

[0039] Among them, the trumpet pipe 7 is connected to the water pump inlet pipe 8; the positions of the columns 6 and the beams 5 correspond one to one; the inlet and outlet ends of the pool body 1 are respectively provided with manholes 9; the middle pier of the connecting culvert outlet extends 2m into the pool body 1 as a diversion wall.

[0040] This article provides the most effective column array layout and sidewall profile scheme, as detailed below: Dozens of columns with a diameter of 1 meter are arranged in the tank to form a column array, which serves both as a support structure and to improve the flow pattern within the tank. The last row of columns is located in the middle of the axis of the bell mouth (bell pipe 7). The sidewall of the pressure forebay adopts a 4-curved boundary, which gradually increases the diffusion angle from small to large. Each column (each vertical row) of columns corresponds to the forebay roof 3, with a beam 5 structure to meet the requirements of column structural strength and roof deformation. The middle pier of the culvert outlet extends 2 meters into the forebay to serve as a diversion wall. This scheme can shorten the length of the forebay in the downstream direction, optimize water flow conditions, and save land and project investment.

[0041] like Figure 3-7 As shown in the figure, the flow field diagrams of the pressure forepool optimization scheme for working conditions 1 to 5 are shown. From the flow field diagrams, we can see that: (1) Under each operating condition, the water flow in the inlet section of the pressure forepool diffuses more evenly, the water flow in the middle section of the pressure forepool close to the side wall diffuses more slowly, and the water flow in the middle diffuses more quickly. The water flow in the rear section of the pressure forepool can flow into the bell pipes of each water pump more smoothly; (2) Under operating condition 2, the water flow of pumps 5 and 6, under operating condition 3, the water flow of pumps 3 and 6, under operating condition 4, the water flow of pumps 4 and 6, and under operating condition 5, turns with a large curvature and enters the bell pipe; (3) Under each operating condition, there is no large-scale backflow area formed by water shedding from the wall in the pressure forepool; (4) No harmful flow patterns such as vortex appear in front of the bell pipe inlet of each operating water pump, and there is a local stagnant water area in front of the bell pipe inlet of the non-operating water pump.

[0042] According to the flow field calculation results, the velocity distribution uniformity and the average water flow angle at the bell pipe outlet of the pressure forebay optimization scheme under various working conditions are increased.

[0043] The structural stress and deformation of the pressure forebay optimization scheme were recalculated by finite element method. The calculated vertical stress distribution of the pressure forebay column and the vertical deformation distribution of the forebay are shown as follows: Figure 8 and Figure 9 As shown; the results show that: the maximum tensile stress of the column array of the pressure forepool optimization scheme is 2.06MPa, which is less than the standard value of concrete tensile strength of 2.20MPa, and the requirements can be met through the reinforcement of the column structure; the maximum deformation value of the pressure forepool top plate is only 0.107mm, which meets the structural deformation limit requirements. Therefore, the pressure forepool optimization scheme can meet the requirements of column structure strength and top plate deformation.

[0044] In summary, this solution optimizes water flow conditions by arranging columns, eliminating the large-scale backflow area in the station's large-divergence-angle pressure forebay and the turbulent flow near the bell pipe. Under all operating conditions, the water flow can flow relatively smoothly to the bell pipe, providing a flow state that meets the conditions for water pump operation and solving the problem of large area occupied by conventional pressure forebays.

[0045] Under the condition that the pressure forebay is controlled to have unchanged dimensions, this application adopts an optimized column array in combination with a quadratic curved sidewall boundary, which satisfactorily solves the problem of a large-scale backflow area in the pressure forebay due to an excessively large diffusion angle. The average values ​​of the flow velocity distribution uniformity and the water flow angle at the outlet of the trumpet tube in each working condition are not less than 98% and 87°, respectively, which provide the necessary conditions for ensuring the normal operation of the water pump unit. The structural stress and deformation of the pressure forebay optimization scheme are recalculated, and the scheme can meet the requirements of the column structure strength and top plate deformation.

[0046] This application was put into trial operation. The actual operation of the pump station after completion showed that the water pump unit operated safely and stably, providing a reference and reference for the construction of similar pump stations.

[0047] Specifically, the Shandong Province Yellow River East Diversion Project includes Phase I and Phase II projects, of which the Weibei Second Plain Reservoir is the regulating reservoir for Phase I and Phase II projects. The Phase II project draws water from the Weibei Second Plain Reservoir, pressurizes the water at the off-dam pump station, and then sends the water to the Yellow River-Jinan-Qingdao and Jiaodong water diversion main canals through water pipelines. The water transmission line is 52.5km long. The pressure pump station adopts a behind-the-embankment layout and is arranged at the outlet culvert of the east dam of the Weibei Second Reservoir. The pump station consists of an outlet culvert, a pressure forebay, main and auxiliary plant buildings, and an outlet pipe. Water is diverted to the pressure forebay through the outlet culvert, and the pump unit draws water from the pressure forebay and pressurizes it to the outlet pipe. The outlet pipe is connected to the main water pipeline.

[0048] The design flow rate of the pump station is 15m 3 / s, with a designed head of 51m, and eight horizontal centrifugal pumps (two spares) installed, totaling 14,400kW. Units are spaced 8.3m apart. The inlet and outlet pipes are DN1400 steel pipes, and the main outlet pipe is two DN2400 steel pipes. The inlet of the forebay is connected to the outlet culvert of the East Dam of the Weibei Second Reservoir. The outlet culvert consists of two 2.5x3m reinforced concrete box culverts, with a 0.6m thick spacer between the two culverts. Based on the layout of the pumping station units, the clear width of the forebay perpendicular to the flow direction is 64.1m. According to the "Design Code for Pumping Stations" (GB50265-2010), which stipulates that the "divergence angle of the forebay should be less than 40°," the clear length of the forebay in the downstream direction should be at least 94m, resulting in significant project investment and land occupation.

[0049] Due to site constraints, the parameters of the proposed pressure forebay are as follows: the length downstream is 50m, the last row of columns consists of seven columns, arranged in the middle of the water pump bell mouth; the inlet and outlet widths of the pressure forebay are 6.6m and 64.1m respectively, and the side walls of the pressure forebay are quaternary curved boundaries, which gradually increase the diffusion angle from small to large; the center pier connecting to the culvert outlet extends 2000mm into the forebay; 43 columns with a diameter of 1m are arranged in the forebay, forming a column array, which serves both as a support structure and to improve the flow pattern within the forebay.

[0050] The second phase of the Yellow River East Diversion Project in Shandong Province has been completed and is operating according to the designed scale. Since the top of the pressure forebay of the pump station is closed with a reinforced concrete cover, the flow state in the forebay cannot be observed. Therefore, on-site tests of the pump station can only be carried out to examine the impact of the flow state in the pump station forebay on the operation of the water pump unit. The on-site test results are: water pump noise 80dB, water pump bearing amplitude 0.03~0.04mm, water pump bearing temperature 27.3~42.4℃, motor bearing temperature 31~54.5℃, stator winding temperature rise 40~69℃. All test results are in line with the relevant specifications and the allowable values ​​specified by the equipment manufacturer. No water pump cavitation was found during operation. The on-site units of the pump station are operating safely and stably. The actual operation of the pump station after completion shows that the hydraulic optimization design of the pressure forebay in this paper has achieved the expected results.

[0051] Although the present invention has been described in detail with reference to the accompanying drawings and in combination with preferred embodiments, the present invention is not limited thereto. Without departing from the spirit and essence of the present invention, ordinary technicians in this field can make various equivalent modifications or substitutions to the embodiments of the present invention, and these modifications or substitutions should all be within the scope of the present invention. Any technician familiar with this technical field can easily think of changes or substitutions within the technical scope disclosed in the present invention, and they should all be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A pressure forebay of a booster pump station, connected to the outlet of a culvert, characterized in that: The invention comprises a pool body, which comprises a bottom plate, a top plate, a side wall and a beam; the side wall of the pool body adopts a quadratic curve boundary; a plurality of columns are arranged in the pool body, and the columns are arranged in nine rows according to the shape and structure of the pool body; the outlet end of the pool body is connected with a trumpet pipe, and the last row of columns is located in the middle of the axis of adjacent trumpet pipes.

2. The pressure forebay of the booster pump station according to claim 1, characterized in that: The first row has two columns, the second row has two columns, the third to sixth rows have one column each, the seventh row has eight columns, the eighth row has six columns, and the ninth row has seven columns; the distance between adjacent rows from the first to the seventh rows is equal, and the distance between the seventh to the ninth rows decreases.

3. The pressure forebay of the booster pump station according to claim 1, characterized in that: The columns in each row are evenly spaced.

4. The pressure forebay of the booster pump station according to claim 1, characterized in that: The trumpet pipe is connected with a water pump water inlet pipe.

5. The pressure forebay of the booster pump station according to claim 1, characterized in that: The positions of the columns and beams correspond one to one.

6. The pressure forebay of the booster pump station according to claim 1, characterized in that: The inlet end and the outlet end of the pool body are respectively provided with entry holes.

7. The pressure forebay of the booster pump station according to claim 1, characterized in that: The middle pier at the outlet of the connecting culvert extends 2m into the pool body to form a diversion wall.

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