Aeration device for relieving supersaturation of water body

Abstract

The utility model relates to the technical field of hydraulic engineering, and discloses an aeration device for relieving water body supersaturation, which comprises an air pump, a hose and an aeration piece, the hose is used for connecting the air pump and the aeration piece, the aeration piece consists of a plurality of aeration units, each aeration unit comprises a plurality of parallel air delivery pipes, N aeration pipes are fixed on each air delivery pipe, a fixing piece is arranged between every two adjacent gas conveying pipes, the aeration pipes in the aeration units are distributed in a matrix mode through the fixing pieces, each aeration pipe is provided with a plurality of aeration holes, the aeration holes are divided into M groups, the grouped aeration holes are distributed in the axial lead direction of the aeration pipes, and the distance between every two adjacent groups of aeration holes is gradually increased from the surface of the water body to the bottom of the water body. The utility model has the beneficial effects that the aeration holes of the underwater aeration pipes which are arranged in a matrix manner are distributed, so that the water-gas interface area can be increased during aeration, the turbulent fluctuation intensity of the water body can be enhanced, and the mass transfer of dissolved oxygen in the water can be promoted, thereby reducing the over-saturation of dissolved gas in the water body under the dam.

Description

Technical Field

[0001] The utility model relates to the technical field of water conservancy projects, in particular to an aeration device for alleviating oversaturation of water bodies. Background Art

[0002] Water reoxygenation is when water is released from weirs, dams, waterfalls and other hydraulic structures, causing strong mixing of air and water. The oxygen contained in the bubbles diffuses in the water, thereby increasing the concentration of dissolved oxygen in the water. Studies have shown that the total dissolved gas supersaturation pressure ΔP in water m Expressed as the total dissolved gas pressure P TDG With atmospheric pressure P B Difference:

[0003] ΔP m =P TDG -P B (1)

[0004] Relative saturation G corresponding to the local atmospheric pressure TDG for:

[0005]

[0006] Aquatic organisms at depth h B The actual supersaturation pressure ΔP comp is the total dissolved gas pressure P TDG With local pressure (P B +ρgh B ) difference:

[0007] ΔP comp =P TDG -(P B +ρgh B )=ΔP m -ρgh B (3)

[0008] Where: ρ is the density of water, kg / m 3 ; g is the acceleration due to gravity, m 2 / .

[0009] Correspondingly, the supersaturation felt by fish underwater is G comp :

[0010]

[0011] The supersaturation pressure ΔP actually felt by aquatic organisms comp Directly determines the biological effect of dissolved gas. If the water depth ΔP comp >0, bubbles will form in the organism and may even induce bubble disease; otherwise, bubbles will not form and will not induce bubble disease.

[0012] In order to solve the problem of oversaturation of downstream water bodies after dam discharge, which leads to bubble disease in downstream organisms, there are usually the following methods:

[0013] 1. Diversion sill: It is built in the spillway to guide the aerated water flow to the surface of the stilling pool, so as to avoid entering the high pressure environment of the bottom layer and causing excessive saturation. However, it is only applicable to low-head hydropower stations with bottom flow energy dissipation, and its application scope is relatively limited. It was first used in the Bonneville Dam on the Columbia River in 1972, reducing the saturation of TDG by 3% to 12%, and its efficiency is relatively low;

[0014] 2. Step (baffle) spillway: Arranging steps or baffles in the spillway can, on the one hand, promote water flow energy dissipation and prevent water flow from sinking into the bottom of the energy dissipation pool, thereby reducing the increase in TDG saturation; on the other hand, it can promote mass transfer at the water-gas interface of the dam surface water flow, thereby improving the dissolved gas level. However, this engineering measure is technically difficult, inefficient, and requires more safety factors to be considered;

[0015] 3. Auxiliary energy dissipation piers: Auxiliary energy dissipation piers are arranged in the energy dissipation pool or downstream of the second dam of the water cushion pond. They mainly improve the energy dissipation efficiency, promote the movement of bubbles to the water surface and the release of supersaturated gas to the water surface. However, the effective addition of energy dissipation piers downstream of the discharge can effectively reduce the generation of supersaturated TDG, but the engineering difficulty and safety hazards still exist;

[0016] 4. Planting vegetation in the lower reaches of the river: The leaves of plants have adsorption capacity. When water passes through, the leaves absorb oxygen, thereby reducing the concentration of TDG. However, this measure is green and effective, but it is difficult to plant and has high maintenance costs;

[0017] 5. Adjust the opening of the flood discharge gate: regulate river flow and control water level. However, for safety during the flood season, this engineering measure cannot achieve significant results.

[0018] Since the above-mentioned measures all have certain shortcomings, they are not the best technical solutions to solve the oversaturation problem downstream of the dam. Utility Model Content

[0019] The utility model aims to provide an aeration device for alleviating oversaturation of water bodies, so as to overcome the shortcomings of the prior art.

[0020] The purpose of the utility model is achieved through the following technical solutions: an aeration device for alleviating oversaturation of a water body, comprising an air pump, a hose and an aeration piece, wherein the hose is used to connect the air pump and the aeration piece, the aeration piece is composed of a plurality of aeration units, the aeration unit comprises a plurality of air pipes parallel to each other, one end of the air pipe is connected to the hose and the other end is closed, each of the air pipes is fixed with N aeration pipes, wherein N is an integer not less than two, the aeration pipes extend radially along the air pipes and are vertically inserted into the water body, fixing members are provided between adjacent air pipes, and the aeration pipes in the aeration unit are distributed in a matrix through the fixing members, each of the aeration pipes is provided with a plurality of aeration holes, the plurality of aeration holes are divided into M groups, the aeration holes in the group are distributed along the axial direction of the aeration pipe, the aeration holes in the same group are distributed circumferentially along the aeration pipe, M is an integer not less than three, and the distance between the aeration holes in adjacent groups increases gradually from the surface to the bottom of the water body.

[0021] Preferably, the outer wall of the aeration tube is coated with an activated carbon layer, and the aeration holes penetrate the activated carbon layer.

[0022] Preferably, the fixing member comprises a plurality of pairs of clamping plates and bolts, wherein the bolts are used to clamp the same pair of the clamping plates on adjacent gas pipes, and arc grooves are formed on the clamping plates, and the gas pipes are clamped in the corresponding arc grooves.

[0023] Preferably, there are a plurality of aeration elements distributed in rows, and adjacent air pipes in the same row are connected via connectors.

[0024] Preferably, the connecting piece comprises an externally threaded tube, an internally threaded sleeve is screwed onto the externally threaded tube, shrinkage seams are provided at both ends of the externally threaded tube, the inner diameter of the internally threaded sleeve gradually decreases, and the internally threaded sleeve is used to clamp the externally threaded tube onto the gas pipe.

[0025] Preferably, an annular groove is provided on the gas delivery pipe located in the externally threaded tube, an O-ring is installed in the annular groove, and the O-ring is compressed and installed in the annular groove through the externally threaded tube.

[0026] Compared with the prior art, the beneficial effects of the utility model are:

[0027] The underwater aeration pipes are arranged in a matrix, and their aeration holes are distributed from dense to sparse from the water surface to the bottom. During aeration, they can increase the water-gas interface area, enhance the turbulence intensity of the water body, and promote the mass transfer of dissolved oxygen in the water, thereby reducing the oversaturation of dissolved gas in the water body below the dam. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a structural schematic diagram of the utility model;

[0029] Figure 2 for Figure 1 A local enlarged schematic diagram of the middle A;

[0030] Figure 3 is a schematic diagram of the structure of the connecting piece;

[0031] In the figure, 1-air delivery pipe, 2-aeration pipe, 3-aeration hole, 4-activated carbon layer, 5-plywood, 6-bolt, 7-external threaded pipe, 8-internal threaded sleeve, 9-contraction joint, 10-O-ring. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme 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 part of the embodiments of the present invention, not all of the embodiments. The components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0033] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention.

[0034] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features thereof may be combined with each other.

[0035] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0036] In the description of the present utility model, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the utility model product is usually placed when in use, or the positions or positional relationships commonly understood by those skilled in the art, which are only for the convenience of describing the present utility model 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, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0037] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" 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 it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] like Figure 1 and 2 As shown, an aeration device for alleviating oversaturation of a water body comprises an air pump, a hose and an aeration member, wherein the hose is used to connect the air pump and the aeration member (the air pump and the hose are not shown in the figure), and the aeration member is composed of a plurality of aeration units, and the aeration unit comprises a plurality of mutually parallel air pipes 1, one end of the air pipe 1 is connected to the hose and the other end is closed, and each air pipe 1 is fixed with N aeration pipes 2, where N is an integer not less than two, and the aeration pipes 2 extend radially along the air pipe 1 and are vertically inserted into the water body, and fixing members are arranged between adjacent air pipes 1, and the aeration pipes 2 in the aeration unit are arranged in a matrix through the fixing members. Each aeration pipe 2 is provided with a plurality of aeration holes 3, and the plurality of aeration holes 3 are divided into M groups. The aeration holes 3 in the group are distributed along the axis direction of the aeration pipe 2, and the aeration holes 3 in the same group are distributed along the circumferential direction of the aeration pipe 2. M is an integer not less than three. The distance between adjacent groups of aeration holes 3 gradually increases from the surface to the bottom of the water body. The underwater aeration pipes 2 arranged in a matrix have aeration holes 3 distributed from the water surface to the bottom in a dense to sparse manner. During aeration, the water-gas interface area can be increased, the turbulence intensity of the water body can be enhanced, and the mass transfer of dissolved oxygen in the water can be promoted, thereby reducing the saturation of dissolved gas in the water body below the dam.

[0039] In this embodiment, if Figure 2 As shown, the outer wall of the aeration tube 2 is coated with an activated carbon layer 4, and the aeration holes 3 penetrate the activated carbon layer 4. The activated carbon has a large specific surface area and pore structure, and can adsorb oxygen in water. When water passes through the activated carbon layer 4, oxygen will be adsorbed by the pores on the surface of the activated carbon, and a thin film will be formed between the activated carbon particles for adsorption. Experiments have shown that when the adsorbent activated carbon is added to the supersaturated water body, the activated carbon with a large surface area can significantly improve the mass transfer coefficient of the supersaturated gas (the amount of material transferred per unit time and per unit area under the action of unit driving force during the mass transfer process).

[0040] In this embodiment, if Figure 1 As shown, the fixing member includes a plurality of pairs of clamping plates 5 and bolts 6. The bolts 6 are used to clamp the same pair of clamping plates 5 on adjacent gas pipes 1. The clamping plates 5 are provided with arc grooves, and the gas pipes 1 are clamped in the corresponding arc grooves. The structure is simple and easy to install.

[0041] In this embodiment, if Figure 1 and 3 As shown, there are several aeration elements and they are distributed in rows. Adjacent gas pipes 1 in the same row are connected by connecting pieces. The connecting pieces include an externally threaded pipe 7 on which an internally threaded sleeve 8 is screwed. Shrinkage seams 9 are provided at both ends of the externally threaded pipe 7. The inner diameter of the internally threaded sleeve 8 gradually decreases. The internally threaded sleeve 8 is used to clamp the externally threaded pipe 7 on the gas pipe 1. An annular groove is provided on the gas pipe 1 inside the externally threaded pipe 7. An O-ring 10 is installed in the annular groove. The O-ring 10 is compressed and installed in the annular groove through the externally threaded pipe 7. When the river channel is widened, multiple aeration elements can be connected together through the connecting piece to cover the entire wide river channel, thereby ensuring the use effect of the utility model.

[0042] It is worth noting that: according to the simulation in a water tank with a length of 2 meters, a width of 40 centimeters and a depth of 39 centimeters, the inner diameter of the gas transmission pipe 1 is 8 mm, with a total of six rows, each row containing four aeration pipes 2, and seventeen groups of aeration holes 3 are distributed from top to bottom on the aeration pipe 2, with three aeration holes 3 in the upper ten groups and two aeration holes 3 in the lower seven groups. After a short period of time, the water body was measured and the water saturation decreased by nearly 27.9%.

[0043] It is reasonable to infer that, taking the Jinsha River as an example, the width of the narrow part of the river is 50-100m, and the average water depth is 20m. Taking the middle width of 75m, the aeration depth is 0.5-4m below the water surface, and designing to lay 15 aeration pipes 2, it is estimated that 20t of stainless steel pipes are required (stainless steel pipe diameter 0.2m, wall thickness 0.075m), designed as 30 rows of dense aeration holes 3, 20 rows of sparse aeration holes 3, and it is reasonable to infer that the expected effect is reduced by 20%-30%. According to different high dam scenarios, the length, diameter and other parameters can be properly adjusted, the number of aeration pipes 2 rows can be appropriately increased to increase efficiency, the number of aeration pipes 2 in each row can be changed, and the spacing can be changed to ensure the normal passage of ships. It can be arranged at any position in the river, and the arrangement is flexible, such as fixed in the form of a bridge, but the aeration pipe 2 must meet the structural form of dense top and sparse bottom, and must be perpendicular to the water surface, that is, vertically inserted into the water body.

[0044] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art may still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. An aeration device for alleviating water oversaturation, comprising an air pump, a hose and an aeration element, wherein the hose is used to connect the air pump and the aeration element, and is characterized in that: The aeration element is composed of a plurality of aeration units, each of which comprises a plurality of mutually parallel air pipes (1), one end of each of which is connected to the hose and the other end is closed, each of which is fixed with N aeration pipes (2), wherein N is an integer not less than two, the aeration pipes (2) extend radially along the air pipes (1) and are vertically inserted into the water body, a fixing member is provided between adjacent air pipes (1), and the aeration pipes (2) in the aeration unit are arranged in a matrix through the fixing member, each of which is provided with a plurality of aeration holes (3), and the plurality of aeration holes (3) are divided into M groups, the aeration holes (3) in a group are distributed along the axial direction of the aeration pipe (2), the aeration holes (3) in the same group are distributed along the circumference of the aeration pipe (2), M is an integer not less than three, and the distance between the aeration holes (3) in adjacent groups increases gradually from the surface to the bottom of the water body.

2. An aeration device for alleviating water oversaturation according to claim 1, characterized in that: The outer wall of the aeration tube (2) is coated with an activated carbon layer (4), and the aeration holes (3) penetrate the activated carbon layer (4).

3. An aeration device for alleviating water oversaturation according to claim 1, characterized in that: The fixing member comprises a plurality of pairs of clamping plates (5) and bolts (6). The bolts (6) are used to clamp the same pair of clamping plates (5) on adjacent gas pipes (1). The clamping plates (5) are provided with arc grooves, and the gas pipes (1) are clamped in the corresponding arc grooves.

4. The aeration device for alleviating water oversaturation according to claim 1, characterized in that: There are a plurality of aeration elements distributed in rows, and adjacent gas pipes (1) in the same row are connected via connecting elements.

5. An aeration device for alleviating water oversaturation according to claim 4, characterized in that: The connecting piece comprises an externally threaded tube (7), an internally threaded sleeve (8) is screwed onto the externally threaded tube (7), both ends of the externally threaded tube (7) are provided with contraction seams (9), the inner diameter of the internally threaded sleeve (8) gradually decreases, and the internally threaded sleeve (8) is used to clamp the externally threaded tube (7) onto the gas transmission pipe (1).

6. An aeration device for alleviating water oversaturation according to claim 5, characterized in that: An annular groove is provided on the gas delivery pipe (1) located inside the externally threaded pipe (7), an O-type sealing ring (10) is installed in the annular groove, and the O-type sealing ring (10) is compressed and installed in the annular groove through the externally threaded pipe (7).

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