Ecological flow discharge device and method for small and medium-sized reservoirs

Abstract

The invention relates to a small and medium-sized reservoir ecological flow discharge device and method.The small and medium-sized reservoir ecological flow discharge device comprises a water storage pond, an ecological flow discharge pipe, an adjusting control valve, a supporting mechanism and a measuring mechanism, the water storage pond is built at the confluence position of a downstream river channel of a target reservoir, and one side wall of the water storage pond communicates with an inlet of the ecological flow discharge pipe; an outlet of the ecological flow discharge pipe is lifted to a set height away from a riverbed through the supporting mechanism, and the adjusting control valve is arranged on the ecological flow discharge pipe and used for adjusting and controlling the flow speed of water flow discharged from the outlet of the ecological flow discharge pipe. The riverbed is provided with a measuring mechanism used for indicating the drop point of water flow discharged through the outlet of the ecological flow discharge pipe so as to indicate whether the current discharge flow meets the ecological flow requirement or not. The ecological flow discharge device and method provided by the invention have better stability, are convenient to construct and low in investment, are suitable for being used in traditional old small and medium-sized reservoirs without ecological flow discharge facilities, can realize ecological flow discharge and monitoring of the small and medium-sized reservoirs at lower construction cost, and are convenient to operate and convenient to manage and protect.

Description

Technical Field

[0001] The present invention belongs to the field of water ecological protection and ecohydrology, and specifically relates to an ecological flow discharge device and method for small and medium-sized reservoirs. Background Art

[0002] Ecological flow refers to the minimum flow required to maintain or restore the basic structure and function of the river, lake and reservoir ecosystems in order to ensure the ecological service function of the river. Ensuring the ecological flow of rivers and lakes is a basic requirement for strengthening the control of water resources development and utilization and promoting the protection and restoration of river and lake ecology. It is related to the construction of ecological civilization and the recovery of the ecological environment of rivers and lakes. In recent years, all large reservoirs have implemented the minimum ecological flow discharge requirements. Local governments and water conservancy departments have also proposed to determine the minimum ecological flow of each reservoir for the ecological dispatch of small and medium-sized reservoirs, improve the reservoir dispatch system, clarify the release method of ecological flow, and ensure the normal release of ecological flow.

[0003] Since most of the small and medium-sized reservoirs in China were built in the 1950s and 1960s, the ecological flow discharge problem was not considered. Therefore, it is not easy to add ecological flow discharge facilities to small and medium-sized reservoirs under the new situation. At present, the common ecological flow discharge facility solutions for small and medium-sized reservoirs include water diversion system modification, small opening discharge of flood gates, spillway gate modification, dam emptying facility modification, setting ecological base load or adopting reverse regulation scheduling, installing ecological units, unit bypass pipe modification, and adding dam water discharge facilities. The above-mentioned technologies require an assessment of the dam structure and construction safety, and have the characteristics of high construction difficulty and high cost. In addition, due to the lack of an ecological flow metering system, it is very easy to cause problems such as water resource waste or insufficient ecological flow discharge. Therefore, in order to meet the current needs of water ecological protection projects in water conservancy projects, it is necessary to develop an ecological flow discharge device and method that is easy to construct and can be measured on the basis of clarifying the ecological flow targets of small and medium-sized reservoirs, so as to improve the ecological flow guarantee rate of small and medium-sized reservoirs and reduce the construction difficulty and cost. Summary of the invention

[0004] The present invention provides an ecological flow discharge device and method for small and medium-sized reservoirs, aiming to overcome the shortcomings of the prior art of ecological flow discharge facilities for small and medium-sized reservoirs, such as great construction difficulty, high cost, lack of effective flow monitoring components or easy failure of flow monitoring components.

[0005] The technical solution of the present invention to solve the above technical problems is as follows: an ecological flow discharge device for small and medium-sized reservoirs, comprising a water storage tank, an ecological flow discharge pipe, a regulating control valve, a supporting mechanism and a measuring mechanism. The water storage tank is built at the confluence of the river channel downstream of the target reservoir. A drain outlet is provided on one side wall of the water storage tank and the drain outlet is connected with the inlet of the ecological flow discharge pipe. The outlet of the ecological flow discharge pipe is lifted to a set height from the riverbed by a supporting mechanism. The regulating control valve is provided on the ecological flow discharge pipe and is used to regulate the flow rate of water discharged from the outlet of the ecological flow discharge pipe. A measuring mechanism is provided on the riverbed or on the side of the riverbed to indicate the landing point of the water discharged through the outlet of the ecological flow discharge pipe on the riverbed to indicate whether the current discharge flow meets the ecological flow requirements.

[0006] On the basis of the above technical solutions, the present invention can also make the following further specific options.

[0007] Furthermore, the supporting mechanism is a pier, the bottom of the pier is placed on the riverbed, and the ecological flow discharge pipe is fixedly supported on the top.

[0008] Furthermore, the measuring mechanism is a measuring scale arranged in a horizontal direction.

[0009] Furthermore, the regulating control valve is an electric butterfly valve or an electric diaphragm valve which can be remotely controlled.

[0010] Furthermore, it also includes a monitoring mechanism for monitoring the point where the water discharged from the outlet of the ecological flow discharge pipe falls on the riverbed.

[0011] Furthermore, the monitoring mechanism is a camera or a camera that can photograph the measuring mechanism and the point where the water flows on the riverbed.

[0012] Furthermore, the monitoring mechanism is a plurality of pressure sensors evenly spaced on the riverbed, and each of the pressure sensors corresponds one-to-one to a corresponding scale value on the measuring mechanism.

[0013] Furthermore, it also includes a flow meter arranged on the ecological flow discharge pipe.

[0014] Furthermore, the outlet pipe section of the ecological flow discharge pipe is arranged horizontally or inclined upward by 1-10 degrees, and the ecological flow discharge pipe, regulating control valve, supporting mechanism and measuring mechanism are provided with two sets matching each other and arranged side by side at intervals.

[0015] The present invention also provides a method for releasing ecological flow of small and medium-sized reservoirs, which includes the following contents:

[0016] Open the regulating control valve and adjust the opening so that the point where the water discharged from the outlet of the ecological flow discharge pipe falls on the riverbed corresponds to the specific scale representing the ecological flow on the measuring mechanism or corresponds to a further area beyond the specific scale; regularly check the falling point of the water flow on the riverbed manually on site or check it remotely and in real time through the monitoring mechanism. If the falling point is too close to the ecological flow discharge pipe and deviates from the specific scale on the measuring mechanism, adjust the opening of the regulating control valve manually on site or remotely so that the falling point returns to the point corresponding to the specific scale representing the ecological flow on the measuring mechanism or corresponds to a further area beyond the specific scale. Continuing this process ensures the discharge of ecological flow from small and medium-sized reservoirs.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The present invention can realize the ecological flow discharge and monitoring of the built old small and medium-sized reservoirs by setting up relatively simple and low-cost civil construction and equipment configuration such as water storage tanks, ecological flow discharge pipes, regulating control valves and measuring mechanisms; it cleverly uses the characteristics that water flows from high places to low places in a parabolic shape and the distance of the landing point is directly related to the leakage flow, so it can realize the ecological flow discharge by simply relying on civil engineering and simple equipment investment, and can monitor whether the ecological flow is met according to the location of the water flow landing point, and further feedback and adjust the regulating control valve accordingly. The method of monitoring the ecological flow by monitoring the water flow landing point is not only less expensive than using a flow meter, but also avoids the problem that the flow meter is prone to failure due to long-term use and the maintenance and replacement are troublesome.

[0019] The monitoring of water flow points can be achieved through traditional monitoring mechanisms such as cameras or sensors. The monitoring mechanisms and regulating control valves can be connected to remote central control devices or mobile terminal signals, so workers can remotely and flexibly adjust the water flow points and external drainage flow rates, which is convenient and efficient.

[0020] The ecological flow discharge device provided by the present invention can also be equipped with a flow meter. The flow meter cooperates with the water flow point measuring mechanism to play a dual flow indication role, which is more secure. No matter whether either the flow meter or the water flow point measuring mechanism fails, it will not affect the monitoring of the ecological flow. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic diagram of an ecological flow discharge device for small and medium-sized reservoirs provided by the present invention;

[0022] Figure 2 for Figure 1 A top view of the discharge device shown looking down from the reservoir side;

[0023] Figure 3 for Figure 1The schematic diagram shows that when the discharge device is in use, the water flowing out through the ecological flow discharge pipe falls on the riverbed in a parabolic shape.

[0024] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0025] 1. Water storage tank; 2. Ecological flow discharge pipe; 3. Regulating control valve; 4. Support mechanism; 5. Measuring mechanism. DETAILED DESCRIPTION

[0026] The principles and features of the present invention are described below in conjunction with the accompanying drawings and specific embodiments. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0027] In the description of the present invention, if terms indicating orientation such as "up", "down", "left", "right", "top", "bottom", "inside" and "outside" are used, the orientation or position relationship indicated is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0028] like Figures 1 to 3 As shown, the present invention provides an ecological flow discharge device for small and medium-sized reservoirs, which includes a water storage tank 1, an ecological flow discharge pipe 2, a regulating control valve 3, a supporting mechanism 4 and a measuring mechanism 5. The water storage tank 1 is built at the confluence of the river channel downstream of the target reservoir. A drainage outlet is provided on one side wall of the water storage tank 1 and the drainage outlet is connected with the inlet of the ecological flow discharge pipe 2. The outlet of the ecological flow discharge pipe 2 is lifted off the riverbed to a set height by the supporting mechanism 4. The regulating control valve 3 is provided on the ecological flow discharge pipe 2 and is used to regulate the flow rate of water discharged from the outlet of the ecological flow discharge pipe 2. A measuring mechanism 5 for indicating the landing point of the water discharged through the outlet of the ecological flow discharge pipe 2 on the riverbed is provided on the riverbed or on the side of the riverbed to indicate whether the current discharge flow meets the ecological flow requirement.

[0029] It should be noted that the construction of a water storage tank at the confluence of the downstream river of the target reservoir refers to the installation of ecological flow discharge facilities at the confluence of the downstream river such as the irrigation channel, spillway, tailwater outlet of the power plant and the outlet of the discharge building of small and medium-sized reservoirs, which shall not affect the safety of the main structure of the water conservancy project. For small and medium-sized reservoirs with flood and irrigation tasks, it is preferred to lay out ecological flow discharge facilities downstream of the project water intake.

[0030] The ecological flow discharge pipe in the ecological flow discharge device for small and medium-sized reservoirs provided by the present invention preferably adopts a ductile iron pipe or a steel pipe with a low roughness coefficient, the pipe diameter is 2r (in m), and the pipe cross-sectional area is S (in m). 2 ),like Figure 1 As shown, a concrete pier (support mechanism) is provided under the pipeline for support, and the height of the lower edge from the ground is h (in m). When the regulating control valve is opened, water flows out from the ecological flow discharge pipe and drops to the ground in a parabolic shape (such as Figure 3 As shown in the figure, the time it takes for the water to fall to the ground is t (in seconds), then the relationship between h and t is:

[0031]

[0032] Where g is the acceleration due to gravity (in m / s 2 );

[0033] therefore,

[0034] The measuring scale (measuring mechanism) is located at the end of the ecological flow discharge pipe and can be placed on the ground (river bed) or on the side corresponding to the ground projection of the discharge pipe. The measuring scale has scales corresponding to the ecological flow value. The value on the measuring scale corresponding to the farthest lateral distance L of water flowing out of the ecological flow discharge pipe is the instantaneous ecological flow Q (in m 3 / s).

[0035] There is a correlation between the flow rate of the ecological flow discharge pipe outlet and the length of the scale corresponding to the point where the water falls on the measuring scale (taking the horizontal setting of the ecological flow discharge pipe outlet section as an example for deduction), and the principle is as follows:

[0036] The lateral velocity of the water flow at the end of the ecological flow discharge pipe is v (in m / s) and has the following relationship with t and L:

[0037]

[0038] The flow rate of the ecological flow discharge pipe is Q 管 , then the ecological flow Q = Q 管 +Q 损 , Q 损 It is the head loss of water flow after it flows out of the ecological flow discharge pipe under the influence of air, special weather, etc. The head loss is very small, and this part of the influence is ignored in the present invention, that is, Q≈Q 管 Then the ecological flow Q = v·S, that is:

[0039]

[0040] Here, π is the ratio of a circle to its circumference.

[0041] Generally, the height h from the bottom of the ecological flow discharge pipe to the ground and the pipe diameter 2r are both determinable values ​​and can be set according to actual needs. It is a fixed value.

[0042] Assumptions Then k is a constant.

[0043] There is the following relationship between the ecological flow Q and the farthest lateral distance L from the ecological flow discharge pipe:

[0044] Q=k·L

[0045] Therefore, the discharged ecological flow Q can be calculated based on the indication L on the measuring scale.

[0046] Determine the minimum ecological flow Q of the target reservoir according to policy documents or technical specifications (guidelines) min In order to make the measuring scale range meet the ecological flow measurement requirements of the target reservoir, the height h of the lower edge of the ecological flow discharge pipe from the ground and the diameter 2r of the ecological flow discharge pipe are constrained, that is, Q ≥ Q min (Ecological flow is lower than Q min No measurement is performed), which guides the design of the ecological flow discharge device provided by the present invention to determine the installation height of the ecological flow discharge pipe, the pipe diameter, the length of the measuring scale, etc.

[0047] In one embodiment of the present invention, in order to facilitate remote flow control: the regulating control valve 3 is a remotely controllable electric butterfly valve or electric diaphragm valve; the discharge device also includes a monitoring mechanism for monitoring the point where the water discharged from the outlet of the ecological flow discharge pipe 2 falls on the riverbed. Specifically, the monitoring mechanism is a camera or a camera that can take pictures of the measuring mechanism and the point where the water falls on the riverbed.

[0048] It can be understood that the gate valve or butterfly valve is an electric control valve, which can be divided into multiple gears, including fully open, half open, or closed, and can also be a type with continuously adjustable opening. The electric control valve can be remotely controlled on a computer or mobile terminal.

[0049] In another embodiment of the present invention, the monitoring mechanism is a plurality of pressure sensors evenly spaced on the riverbed, and each of the pressure sensors corresponds one-to-one to a corresponding scale value on the measuring mechanism.

[0050] In another embodiment of the present invention, in order to ensure that the ecological flow monitoring is more accurate and provide an additional safeguard, the ecological flow discharge device also includes a flow meter provided on the ecological flow discharge pipe 2 .

[0051] It should be noted that when the project budget is sufficient and the requirements for ecological flow discharge are high, a flow meter can be added to the ecological flow discharge pipe of the present invention, which can directly measure the water flow rate flowing out of the ecological flow discharge pipe. Generally speaking, the flow rate measured by the flow meter is basically equal to the flow rate corresponding to the drop point on the measuring scale, and the difference should not be greater than 3%. If the difference is too large, the flow meter should be inspected and confirmed to function.

[0052] In the above embodiments of the present invention, the outlet pipe section of the ecological flow discharge pipe 2 is set horizontally. In addition, when necessary, in order to ensure that the water flow in the outlet pipe section completely fills the pipe section before rushing out at a certain speed, so as to ensure the accuracy of the flow indicated by the measuring scale, the outlet pipe section can also be set to be tilted 1-10 degrees upward. After being tilted at a certain angle, the outlet flow of the ecological flow discharge pipe and the flow value reflected by the scale on the measuring scale need to be calibrated. The principle can be deduced by referring to the relationship between the position of the landing point and the initial velocity of a water flow with a certain initial velocity at a certain upward angle falling in a parabolic shape, which will not be elaborated here.

[0053] In the above embodiments of the present invention, the ecological flow discharge pipe 2, the regulating control valve 3, the supporting mechanism 4 and the measuring mechanism 5 are provided in two sets which match each other and are arranged side by side at intervals.

[0054] It should be noted that the advantage of using the above-mentioned two sets of discharge devices arranged in parallel is that usually one set is selected for use, and then the other set can be switched for use after a certain interval to perform maintenance and repair on the previously used set.

[0055] The present invention also provides a method for releasing ecological flow of small and medium-sized reservoirs, which includes the following contents:

[0056] Open the regulating control valve 3 and adjust the opening so that the point where the water discharged from the outlet of the ecological flow discharge pipe 2 falls on the riverbed corresponds to the specific scale representing the ecological flow on the measuring mechanism 5 or corresponds to a further area beyond the specific scale; regularly check the point where the water falls on the riverbed manually on site or check it remotely and in real time through the monitoring mechanism. If the point is too close to the ecological flow discharge pipe 2 and deviates from the specific scale on the measuring mechanism 5, adjust the opening of the regulating control valve 3 manually on site or remotely so that the point returns to the point that corresponds to the specific scale representing the ecological flow on the measuring mechanism 5 or corresponds to a further area beyond the specific scale. Continuing this process ensures the discharge of ecological flow from small and medium-sized reservoirs.

[0057] The above-mentioned discharge device and method provided by the present invention have good stability, are easy to construct, require little investment, and are suitable for use in old small and medium-sized reservoirs that traditionally do not have ecological flow discharge facilities. They can achieve ecological flow discharge for small and medium-sized reservoirs with a relatively low construction cost, and are easy to operate and maintain.

[0058] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An ecological flow discharge device for small and medium-sized reservoirs, characterized in that: The invention comprises a water storage tank (1), an ecological flow discharge pipe (2), a regulating control valve (3), a supporting mechanism (4) and a measuring mechanism (5). The water storage tank (1) is built at the confluence of the river downstream of the target reservoir. A drainage outlet is provided on one side wall of the water storage tank (1) and the drainage outlet is connected to the inlet of the ecological flow discharge pipe (2). The outlet of the ecological flow discharge pipe (2) is lifted off the riverbed to a set height by the supporting mechanism (4). The regulating control valve (3) is provided on the ecological flow discharge pipe (2) and is used to regulate the flow rate of water discharged from the outlet of the ecological flow discharge pipe (2). A measuring mechanism (5) is provided on the riverbed or on the side of the riverbed to indicate the landing point of the water discharged from the outlet of the ecological flow discharge pipe (2) on the riverbed, so as to indicate whether the current discharge flow meets the ecological flow requirement.

2. The ecological flow discharge device for small and medium-sized reservoirs according to claim 1 is characterized in that: The supporting mechanism (4) is a pier, the bottom of which is placed on the riverbed, and the ecological flow discharge pipe (2) is fixedly supported on the top.

3. The ecological flow discharge device for small and medium-sized reservoirs according to claim 1 is characterized in that: The measuring mechanism (5) is a measuring scale arranged in the horizontal direction.

4. The ecological flow discharge device for small and medium-sized reservoirs according to claim 1 is characterized in that: The regulating control valve (3) is an electric butterfly valve or an electric diaphragm valve that can be remotely controlled.

5. The ecological flow discharge device for small and medium-sized reservoirs according to claim 4 is characterized in that: It also includes a monitoring mechanism for monitoring the point where the water discharged from the outlet of the ecological flow discharge pipe (2) falls on the riverbed.

6. The ecological flow discharge device for small and medium-sized reservoirs according to claim 5 is characterized in that: The monitoring mechanism is a camera or a camera that can photograph the measuring mechanism and the point where the water flows on the riverbed.

7. The ecological flow discharge device for small and medium-sized reservoirs according to claim 5, characterized in that: The monitoring mechanism is a plurality of pressure sensors evenly spaced on the riverbed, and each of the pressure sensors corresponds one-to-one to a corresponding scale value on the measuring mechanism.

8. The ecological flow discharge device for small and medium-sized reservoirs according to claim 1 is characterized in that: It also includes a flow meter arranged on the ecological flow discharge pipe (2).

9. An ecological flow discharge device for small and medium-sized reservoirs according to any one of claims 1 to 8, characterized in that: The outlet pipe section of the ecological flow discharge pipe (2) is arranged horizontally or inclined upward by 1-10 degrees. The ecological flow discharge pipe (2), the regulating control valve (3), the supporting mechanism (4) and the measuring mechanism (5) are provided in two sets matching each other and arranged side by side at intervals.

10. A method for releasing ecological flow from small and medium-sized reservoirs, characterized in that: It includes the following: Opening the regulating control valve (3) and adjusting the opening so that the point where the drainage water from the outlet of the ecological flow discharge pipe (2) falls on the riverbed corresponds to a specific scale representing the ecological flow on the measuring mechanism (5) or corresponds to a further area beyond the specific scale; The point where the water flows on the riverbed is checked regularly on-site manually or in real time remotely through a monitoring device. If the point where the water flows is too close to the ecological flow discharge pipe (2) and deviates from the specific scale on the measuring device (5), the opening of the regulating control valve (3) is adjusted on-site manually or remotely so that the point where the water flows returns to the specific scale on the measuring device (5) representing the ecological flow or to a further area beyond the specific scale. If this continues, the ecological flow discharge of small and medium-sized reservoirs is guaranteed.

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