A test device and method for measuring surge water level of a model of a surge chamber of a hydropower station

Abstract

The application discloses a kind of experimental devices for measuring surge water level of hydropower station surge chamber model, including with the communication of hydropower station surge chamber model main pipeline, the two ends of the main pipeline are communicated to tail water container and upstream water container, main pipeline valve and pneumatic valve are further provided between the main pipeline and the tail water container, and the pneumatic valve is used to simulate unit load rejection condition when instantaneous closing.This device can accurately simulate unit load rejection condition, improve the measurement accuracy of surge chamber surge water level fluctuation, obtain more accurate surge chamber hydraulic performance index, also can ensure to test continuous stable water supply, help the optimization design of surge chamber, reduce the volume of surge chamber, reduce manufacturing and operating cost, improve engineering safety and economy.The application further discloses a kind of experimental methods for measuring surge water level of hydropower station surge chamber model.

Description

Technical Field

[0001] This invention belongs to the field of hydropower station engineering model testing technology, and in particular relates to a test device and method for measuring the surge water level of a hydropower station surge chamber model. Background Technology

[0002] Hydropower stations experience sudden load shedding during operation, causing changes in generator speed, spiral casing pressure, and surge tank water level. When the turbine-generator unit sheds load, it causes an increase in water pressure in the pressure pipes and spiral casing, as well as a rapid increase in generator speed. Conversely, when the turbine-generator unit increases load, it causes a sudden drop in water pressure in the pressure pipes, potentially even creating a vacuum. Surge tanks in hydropower stations effectively improve their regulation characteristics. The surge water level is a key indicator of the surge tank's hydraulic performance, which is related to its design height. Because actual power stations shut down quickly during load shedding, scaled-down physical model tests require higher precision. Existing model test setups using manual flow adjustment for shutdown cannot accurately simulate load shedding conditions. Furthermore, existing model test setups rely on a simplistic water tank control method, relying solely on pumps. This lack of a stable upstream head during water circulation results in poor test data accuracy and hinders optimized comparative tests. Summary of the Invention

[0003] To address the aforementioned problems, this invention provides a test apparatus and method for measuring the surge water level of a surge chamber model in a hydropower station. This apparatus can accurately simulate the load shedding condition of the unit, improve the measurement accuracy of surge water level fluctuations in the surge chamber, obtain more accurate hydraulic performance indicators of the surge chamber, and ensure a continuous and stable water supply for the test. This also helps in the optimized design of the surge chamber, reduces its volume, lowers manufacturing and operating costs, and improves the safety and economy of the project.

[0004] The present invention provides a test device for measuring the surge water level of a surge chamber model of a hydropower station, including a main pipeline connected to the surge chamber model of the hydropower station. The two ends of the main pipeline are respectively connected to the tailrace container and the upstream water container. A main pipeline valve and a pneumatic valve are also provided between the main pipeline and the tailrace container. The pneumatic valve is used to simulate the load shedding condition of the unit when it is closed instantaneously.

[0005] Preferably, in the above-mentioned test device for measuring the surge water level of the surge chamber model of a hydropower station, the upstream water container is also connected to the water supply component.

[0006] Preferably, in the above-mentioned test device for measuring the surge water level of a model surge chamber in a hydropower station, the water supply component includes a lower water container and a water pump connected to the lower water container.

[0007] Preferably, in the above-mentioned test device for measuring the surge water level of the surge chamber model of a hydropower station, the tailrace container is also connected to the lower water container through a drain pipe.

[0008] Preferably, in the above-mentioned test device for measuring the surge water level of the surge chamber model of a hydropower station, the pneumatic valve is also connected to an air compressor.

[0009] Preferably, in the above-mentioned test device for measuring the surge water level of the surge chamber model of a hydropower station, a triangular weir flow meter is installed inside the tailrace container.

[0010] Preferably, in the above-mentioned test device for measuring the surge water level of the surge chamber model of a hydropower station, a cross-shaped overflow valve is installed in the upstream water container.

[0011] Preferably, in the above-mentioned test device for measuring the surge water level of the surge chamber model of a hydropower station, an upstream water container control valve is also provided between the upstream water container and the water pump to control the inlet and outlet of the upstream water container.

[0012] The present invention provides a test method for measuring the surge water level of a surge chamber model in a hydropower station, utilizing the test apparatus described in any of the above claims, and comprising the following steps:

[0013] Fill the upstream water container with water, adjust the opening of the main pipeline valve, and purge the air from the main pipeline until the water level in the hydropower station surge tank model remains stable.

[0014] The pneumatic valve is inflated to a preset pressure value and then instantly closed to simulate the unit's load shedding condition. The highest and lowest surge water levels of the first fluctuation cycle, as well as the highest and lowest surge water levels of the second fluctuation cycle, are obtained in the hydropower station surge chamber model.

[0015] Open the pneumatic valve to restore the hydropower station surge tank model to its initial water level. After waiting for a preset time, repeat the above steps for the next round of testing.

[0016] Preferably, in the above-mentioned test method for measuring the surge water level of the surge chamber model of a hydropower station, the test is repeated 10 times to obtain 10 sets of test data, and the effect of the surge chamber model of the hydropower station is evaluated based on the 10 sets of test data.

[0017] As described above, the experimental apparatus for measuring the surge water level of a hydropower station surge chamber model provided by this invention includes a main pipeline connected to the hydropower station surge chamber model. The two ends of the main pipeline are connected to the tailrace container and the upstream water container, respectively. A main pipeline valve and a pneumatic valve are also installed between the main pipeline and the tailrace container. The pneumatic valve is used to simulate the unit's load shedding condition when closed instantaneously. It is evident that the use of a pneumatic valve to simulate the unit's load shedding condition allows for faster instantaneous valve closure, thus accurately simulating the actual unit's load shedding condition. This improves the measurement accuracy of the surge water level fluctuation in the surge chamber, resulting in more accurate hydraulic performance indicators for the surge chamber. Furthermore, the inclusion of an upstream water container to simulate the actual upstream reservoir ensures a continuous and stable water supply for the experiment, facilitating optimized surge chamber design, reducing surge chamber volume, lowering manufacturing and operating costs, and improving engineering safety and economy. The experimental method for measuring the surge water level of a hydropower station surge chamber model provided by this invention has the same advantages as the experimental apparatus for measuring the surge water level of a hydropower station surge chamber model. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0019] Figure 1 A schematic diagram of an embodiment of a test device for measuring the surge water level of a model surge chamber in a hydropower station, provided by the present invention;

[0020] Figure 2 This is a schematic diagram of an embodiment of a test method for measuring the surge water level of a model surge chamber in a hydropower station provided by the present invention;

[0021] Figure 3 This is a diagram showing the fluctuation of the surge water level in the surge chamber. Detailed Implementation

[0022] The core of this invention is to provide a test device and method for measuring the surge water level of a model surge chamber in a hydropower station. This device can accurately simulate the load shedding condition of the unit, improve the measurement accuracy of surge water level fluctuations in the surge chamber, obtain more accurate hydraulic performance indicators of the surge chamber, and ensure a continuous and stable water supply for the test. This is conducive to the optimized design of the surge chamber, reduces its volume, lowers manufacturing and operating costs, and improves the safety and economy of the project.

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] An example implementation of the experimental apparatus for measuring the surge water level of a model surge chamber in a hydroelectric power station provided by this invention. Figure 1 , Figure 1 This is a schematic diagram of an embodiment of a test device for measuring the surge water level of a hydropower station surge chamber model provided by the present invention. The test device for measuring the surge water level of a hydropower station surge chamber model may include a main pipe 2 connected to the hydropower station surge chamber model 1. The two ends of the main pipe 2 are respectively connected to the tailrace container 3 and the upstream water container 4. A main pipe valve 5 and a pneumatic valve 6 are also provided between the main pipe 2 and the tailrace container 3. The pneumatic valve 6 is used to simulate the unit's load shedding condition when it is closed instantaneously.

[0025] It should be noted that the purpose of this device is to test the pressure regulating performance of different hydropower station surge chamber models. These surge chamber models can be any existing surge chambers; there are no restrictions here. A scale can be attached to observe water level fluctuations. The main pipeline valve 5 is used to control the flow rate in the main pipeline 2, thus adjusting the initial water level of the surge chamber. The pneumatic valve 6 is also used to control the flow rate in the main pipeline 2, but its most important function is to achieve instantaneous closure to simulate load shedding conditions, offering the advantage of more accurate simulation of actual conditions. The water in the upstream water container 4 must be maintained at a certain height to ensure a continuous and stable water supply to the main pipeline. During normal operation, instantaneously closing the pneumatic valve 6 can simulate the unit's load shedding condition. The surge water level in the hydropower station surge chamber model at this time is measured, and the performance of the surge chamber model can then be judged based on the surge water level value. It is evident that this experimental device can more accurately simulate real-world load shedding conditions, and based on this, a more accurate surge water level can be obtained.

[0026] As described above, the experimental device for measuring the surge water level of a hydropower station surge chamber model provided by the present invention includes a main pipeline connected to the hydropower station surge chamber model. The two ends of the main pipeline are connected to the tailrace container and the upstream water container, respectively. A main pipeline valve and a pneumatic valve are also installed between the main pipeline and the tailrace container. The pneumatic valve is used to simulate the unit's load shedding condition when it is instantly closed. Therefore, the valve closes faster, which can accurately simulate the actual unit's load shedding condition, thereby improving the measurement accuracy of the surge water level fluctuation in the surge chamber and obtaining more accurate hydraulic performance indicators of the surge chamber. Furthermore, because an upstream water container is set up to simulate the actual upstream reservoir, a continuous and stable water supply for the test can be guaranteed, which helps to optimize the design of the surge chamber, reduce its volume, lower manufacturing and operating costs, and improve engineering safety and economy.

[0027] In a specific embodiment of the test apparatus for measuring the surge water level of a model surge chamber in a hydropower station, the upstream water container 4 can also be connected to a water supply component 7. The form of the water supply component 7 is not limited, as long as it can supply water to the upstream water container 4 to ensure that the water level meets the requirements. Furthermore, the water supply component 7 may include a downstream container 701 and a water pump 702 connected to the downstream container 701. The downstream container 701 is used to store water, and the water pump 702 can transport the water from the downstream container 701 to the upstream water container 4, ensuring sufficiently high working efficiency. The water pump is preferably a centrifugal pump, but other transportation methods can also be used; there are no limitations here.

[0028] In another specific embodiment of the test apparatus for measuring the surge water level of the surge chamber model in a hydropower station, refer to... Figure 1 The tailwater container 3 can also be connected to the lower water container 701 through the drain pipe 8, so that the water in the tailwater container 3 can enter the lower water container 701. The entire test device realizes internal water circulation, and multiple test processes can be carried out without external water supply. This provides a dynamically stable upstream water head for the test device, which saves water resources.

[0029] In another specific embodiment of the test device for measuring the surge water level of the surge chamber model of the hydropower station, the pneumatic valve 6 can also be connected to an air compressor. The air compressor can close the pneumatic valve more quickly, thus better simulating the actual load shedding condition.

[0030] In a preferred embodiment of the test apparatus for measuring the surge water level of a model surge chamber in a hydropower station, a triangular weir flowmeter can preferably be installed inside the tailrace container to measure the flow rate within the tailrace container. Furthermore, a cross-shaped overflow valve can be installed inside the upstream water container 4 to facilitate controlling the water level and maintaining it at a set height, ensuring a continuous and stable water supply. Further, refer to... Figure 1 An upstream water container control valve 9 can also be installed between the upstream water container 4 and the water pump 702 to control the inlet and outlet of the upstream water container 4.

[0031] An example of the implementation of the experimental method for measuring the surge water level of a surge chamber model in a hydroelectric power station provided by this invention. Figure 2 As shown, Figure 2 This is a schematic diagram of an embodiment of a test method for measuring the surge water level of a surge chamber model in a hydropower station provided by the present invention. Utilizing the test apparatus as described above, the method includes the following steps:

[0032] S1: Fill the upstream water container with water, adjust the opening of the main pipeline valve, and purge the air from the main pipeline until the water level in the hydropower station surge tank model remains stable.

[0033] The specific operation can be as follows: open the control valve of the upstream water container, start the water pump, pump the water in the downstream water container to the upstream water container, start water storage, continuously adjust the opening of the main pipeline valve, remove the air in the pipeline, make the water flow more stable, and observe whether the initial water level in the pressure regulating chamber is stable.

[0034] S2: Inflate the pneumatic valve to the preset pressure value, and then close the pneumatic valve instantly to simulate the unit's load shedding condition. Obtain the highest and lowest surge water levels in the first fluctuation cycle, as well as the highest and lowest surge water levels in the second fluctuation cycle, from the hydropower station surge chamber model.

[0035] The specific operation can be as follows: the air compressor is connected to the power supply and starts to inflate the air until the pressure reaches the set value. The pneumatic valve is then closed instantly to simulate the unit's load shedding situation. The highest and lowest surge water levels in the first fluctuation cycle of the pressure regulating chamber are observed and recorded; the highest and lowest surge water levels in the second fluctuation cycle are also recorded.

[0036] S3: Open the pneumatic valve to restore the hydropower station surge tank model to its initial water level. After waiting for the preset time, repeat the above steps to conduct the next round of testing.

[0037] In other words, steps S2 and S3 can be repeated to complete multiple rounds of testing.

[0038] In a specific embodiment of the above-described experimental method for measuring the surge water level of a surge tank model in a hydropower station, the experiment can be repeated 10 times to obtain 10 sets of experimental data. The effectiveness of the surge tank model can then be evaluated based on these 10 sets of data. This method of multiple measurements reduces random errors in the experiment and ensures the accuracy and reliability of the experimental data. Using the aforementioned device for physical model experiments allows for the study of the hydraulic performance of the surge tank, providing a basis for further optimization or design of the surge tank.

[0039] The above experimental method will be illustrated with a specific example below:

[0040] Taking the impedance-type pressure regulating chamber model as an example, the diameter of the chamber cylinder is 32.2 cm and the diameter of the impedance orifice is 7 cm. The test is conducted using the above-mentioned experimental device, including the following steps:

[0041] (1) Open the control valve of the upstream water container, start the water pump, and pump the water from the downstream water container to the upstream water container to start storing water. Continuously adjust the opening of the main pipeline valve to remove the air in the pipeline. After the water flow is stable, adjust the opening of the main pipeline valve to control the initial water level of the pressure regulating chamber to be stable at 260.0 cm.

[0042] (2) The air compressor is connected to the power supply and starts to pressurize the air until the pressure reaches 0.8 MPa. The pneumatic valve is closed instantly to simulate the load shedding condition of the unit. The highest and lowest surge water levels in the first fluctuation cycle of the pressure regulating chamber, as well as the highest and lowest surge water levels in the second fluctuation cycle, are observed and recorded.

[0043] (3) Open the pneumatic valve to restore the water level in the pressure regulating chamber to the initial water level of 260cm. After waiting for a certain period of time for the water flow to stabilize, repeat step (2) and then carry out the next round of testing.

[0044] Repeat steps (2) and (3) above ten times, and record and organize the test data as shown in Table 1. Table 1 is the test result table of the impedance-type voltage regulating chamber.

[0045] Table 1

[0046] 1 260.0 276.4 256.2 270.8 259.2 2 260.0 276.3 256.3 270.9 259.3 3 260.0 276.2 256.2 270.9 259.3 4 260.0 276.4 256.3 270.8 259.4 5 260.0 276.4 256.1 270.6 256.1 6 260.0 276.5 256.0 270.8 259.4 7 260.0 276.6 255.9 271.0 259.0 8 260.0 276.6 255.9 270.8 259.0 9 260.0 276.6 255.8 271.0 259.0 10 260.0 276.8 255.9 271.0 259.0

[0047] The average value of these 10 sets of experimental data was taken, and the highest surge level of the impedance-type surge tank model with an initial water level of 260.0 cm was found to be 276.48 cm. Based on this data, the following was obtained: Figure 3 , Figure 3 The diagram shows the surge wave and water level fluctuation in the surge chamber. It can be seen that the impedance-type surge chamber exhibits small amplitude and rapid attenuation of water level fluctuations, demonstrating a good suppression effect on the surge chamber's water level fluctuations. Of course, by replacing the surge chamber model in the above experimental setup with another model, the performance of that other model can be tested.

[0048] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A test method for measuring the surge water level of a surge chamber model in a hydroelectric power station, characterized in that, The test was conducted using a device for measuring the surge water level of a model of a hydropower station's surge chamber. The device includes a main pipeline connected to the model of the surge chamber, with its two ends connected to a tailrace container and an upstream water container, respectively. A main pipeline valve and a pneumatic valve are installed between the main pipeline and the tailrace container. The pneumatic valve is used to simulate the unit's load shedding condition when it is momentarily closed. The pneumatic valve is also connected to an air compressor. A cross-shaped overflow valve is installed in the upstream water container. The upstream water container is also connected to a water supply component. The water supply component includes a lower water container and a water pump connected to the lower water container. The tailrace container is also connected to the lower water container via a drain pipe. A triangular weir flow meter is installed in the tailrace container. An upstream water container control valve is also installed between the upstream water container and the water pump to control the inflow and outflow of water into the upstream water container. The experimental method includes the following steps: Fill the upstream water container with water, adjust the opening of the main pipeline valve, and purge the air from the main pipeline until the water level in the hydropower station surge tank model remains stable. The pneumatic valve is pressurized to a preset pressure value and then instantly closed to simulate the unit's load shedding condition. The highest and lowest surge water levels of the first fluctuation cycle, as well as the highest and lowest surge water levels of the second fluctuation cycle, are obtained in the hydropower station surge chamber model. Open the pneumatic valve to restore the hydropower station surge tank model to its initial water level. After waiting for a preset time, repeat the above steps for the next round of testing.

2. The test method for measuring the surge water level of a surge chamber model in a hydropower station according to claim 1, characterized in that, The experiment was repeated 10 times to obtain 10 sets of experimental data. The effectiveness of the hydropower station surge tank model was evaluated based on the 10 sets of experimental data.

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