Pumped storage model test device capable of measuring sand content passing through machine and test method of pumped storage model test device

Abstract

The invention belongs to the technical field of pumped storage power station model testing, and particularly discloses a pumped storage model testing device capable of measuring the sand content passing through a machine and a testing method thereof.The device comprises an upper model reservoir, a lower model reservoir and a forebay, and a pumping model and a drainage model are arranged between the upper model reservoir and the lower model reservoir; the water pumping model and the water discharging model are each composed of an intelligent flow control module, a machine-passing sediment monitoring module and a water conveying pipeline. According to the pumped storage model test device capable of measuring the sand content passing through the machine and the test method of the pumped storage model test device, the sand content passing through the machine is measured in real time according to the operation condition of a pumped storage power station from the angle of model test, and the response change of the sand content to different water and sand conditions is investigated; scientific basis is provided for water pump safe operation and sediment control strategy optimization, and then the problem that in the prior art, monitoring and understanding of the sand content passing through the pump in the actual operation process of the pumped storage power station are insufficient is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of pumped storage power station model testing, and in particular relates to a pumped storage model testing device capable of measuring sediment content passing through a machine and a testing method thereof. Background Art

[0002] In recent years, my country's installed capacity of clean energy sources, such as wind and solar, has continued to climb, but their output is significantly affected by natural conditions. Pumped-storage hydropower stations, as key facilities for shaving peak loads and balancing the volatility of renewable energy, play a crucial role in building a new power system.

[0003] Of my country's nine newly planned clean energy bases, over half are located in sediment-laden river basins, such as the middle and upper reaches of the Yellow River and the Jinsha River. However, the water in these areas carries significant amounts of sediment. During pumping and power generation, the combined effects of water and sediment on turbine blades and flow paths cause severe erosion damage, reduced efficiency, and shortened equipment life. Therefore, precise control and monitoring of sediment concentrations passing through turbines has become a core challenge in the design, operation, and optimization of pumped-storage power plants on sediment-laden rivers.

[0004] Currently, the amount of sediment passing through pumped-storage power stations can be determined through mathematical models (see Chinese Invention Patents CN201610705864.2 and CN202310872576.6 for related patents). However, validation of these models requires extensive real-world data, and currently, insufficient measured data on sediment passing through pumped storage stations makes the model's reliability difficult to guarantee. Existing pumped-storage model tests primarily focus on the hydraulic characteristics of pumped-storage power station inlets and outlets (see Chinese Invention Patents CN202311232379.4 for related patents). However, there is a lack of clear understanding of the real-time changes in sediment concentration passing through pumped storage stations during actual operation, and its relationship to the sediment concentration at the water intake.

[0005] Therefore, there is a need in the art to develop a pumped storage model test device and a test method thereof that can measure the sediment content of the pumped storage model, which can effectively solve the above problems. Summary of the Invention

[0006] The purpose of the present invention is to provide a pumped storage model test device and a test method thereof that can measure the sediment content passing through the machine. From the perspective of model testing, the sediment content passing through the machine is measured in real time according to the operating conditions of the pumped storage power station, and its response changes to different water and sediment conditions are examined, providing a scientific basis for the safe operation of the water pump and the optimization of the sediment control strategy, thereby solving the problem of insufficient monitoring and understanding of the sediment content passing through the machine during the actual operation of the pumped storage power station in the existing technology.

[0007] To achieve the above-mentioned objectives, the present invention provides a pumped storage model test device capable of measuring the sediment content passing through the pump, comprising a model upper reservoir, a model lower reservoir, and a forebay. A pumping model and a discharge model are provided between the model upper reservoir and the model lower reservoir; the pumping model and the discharge model are both composed of a flow intelligent control module and a flow sediment monitoring module; both ends of the flow intelligent control module are provided with a flow sediment monitoring module; the flow intelligent control module and the flow sediment monitoring module, as well as the model upper reservoir, the model lower reservoir and the flow sediment monitoring module are all connected by water pipelines.

[0008] Preferably, the model upper reservoir and the model lower reservoir are adapted to the shape of the prototype reservoir and are scaled; the material of the model upper reservoir and the model lower reservoir are both LLDPE material.

[0009] Preferably, a sand inlet and a stirring pump are provided in the forebay, and the forebay is connected to the model lower reservoir via a first water pump and a PVC steel hose. A certain amount of clean water is placed in the forebay. Based on the test requirements, a corresponding amount of sediment is added to the sand inlet. The stirring pump is turned on to evenly mix the water and sediment until the set sediment concentration is reached. The water is then pumped into the model lower reservoir via the PVC steel hose.

[0010] The forebay is connected to the model lower reservoir and is used to mix clean water and sediment to ensure that the sediment content entering the model lower reservoir remains unchanged during the test.

[0011] Preferably, the flow intelligent control module is composed of an intelligent DN32 anti-corrosion lining electromagnetic flowmeter, a PLC controller, a frequency converter, and a second water pump; The electromagnetic flowmeter is used to indicate the water flow rate in the pipeline in real time, and convert the flow value into a standard process signal, which is transmitted to the analog input module of the PLC through a signal cable.

[0012] The PLC controller pre-sets the target flow value. It receives the real-time flow signal from the flow meter, compares it with the preset target flow setting value, and performs calculations based on the preset PID (proportional-integral-differential) control algorithm to generate and output the corresponding control signal.

[0013] The second pump directly changes the flow rate within the water pipeline by varying its speed, achieving dynamic control of the flow rate. Each of the two water pipelines is equipped with a water pump to simulate the pumping state of a pumped-storage power station, pumping and discharging sediment-laden water with a certain sediment concentration between the model lower and upper reservoirs.

[0014] The pump sediment monitoring module includes a Model 3150 infrared sand meter, a sediment monitoring sensor, a pump sediment sampling port, and a recording terminal. The sediment monitoring sensor is located on the inner wall of the water pipe at both ends (upstream and downstream) of the flow intelligent control module. Its data is recorded on the terminal, simulating real-time monitoring of pump sediment content. The pump sediment sampling port is located outside the water pipe of the sediment monitoring sensor. The Model 3150 infrared sand meter measures the sediment content of water samples taken upstream and downstream of the pump through the pump sediment sampling port for calibration and verification with the sediment monitoring sensor data.

[0015] The flow intelligent control module and the water delivery pipeline are connected through a socket-and-spigot connection, and the gap between the two is filled with adhesive.

[0016] Preferably, a PVC steel wire hose is provided between the model upper reservoir, the model lower reservoir and the water supply pipeline; the water supply pipeline includes a UPVC straight pipe and a UPVC 90-degree large arc elbow, both of which are transparent and visible. The internal structure can be clearly observed with the naked eye under normal lighting conditions, thereby facilitating the observation of the water and sand movement state during the experiment.

[0017] The water pipeline, intelligent flow control module, and sediment monitoring module are preferably fixed to the load-bearing bracket. Ring clamps are installed every 30 cm to secure the pipeline. The load-bearing bracket uses a 5 cm × 10 cm cross-section profile. The bottom of the load-bearing bracket is equipped with several M16 adjustable support pads (D80 × M16 × L100). The support pads can be adjusted in 10 cm heights to adapt to different foundation conditions.

[0018] The present invention also provides a test method for a pumped storage model test device capable of measuring sediment content passing through a machine, comprising the following steps: Step S1: according to the model test conditions, water is released into the model upper reservoir to the dead water level; Step S2: Determine the sediment content of the model lower reservoir and the total amount of water to be pumped based on the model test conditions, add water and sediment to the forebay and stir until the sediment content reaches the test conditions, and then start the test after entering the model lower reservoir; Step S3: According to the model test conditions, the flow intelligent control module controls and sets the pumping flow, pumping time, still water time, discharge flow, discharge time, and number of cycles to simulate the entire process of pumping, still water, and discharge of a pumped storage power station; Step S4: Take water samples five times at equal intervals of one-fifth of the pumping and draining time at the sediment sampling ports of the pumping model and the draining model, and mark the sampling time. Step S5: Stir each of the water samples evenly and measure the sediment content using an infrared sand meter, and compare, calibrate, and verify the data with the sediment content monitoring sensor; Step S6: Establish a graph showing the change of sediment content at different times, and conduct a series of tests and quantitative research on the factors affecting the sediment content of the machine according to the model test conditions.

[0019] The present invention uses the above-mentioned pumped storage model test device and test method capable of measuring sediment content through the machine, and has the following beneficial effects: (1) It can conduct relatively accurate real-time dynamic monitoring of sediment passing through the pump: The pumped storage model test device in the present invention realizes the real-time measurement and synchronous data collection of sediment content passing through the pump through the coordinated deployment of sediment content monitoring sensors and sampling rates, while ensuring the consistency and credibility of the data, providing real-time data support for the response analysis of sediment passing through the pump under dynamic working conditions.

[0020] (2) Ability to conduct test simulation of the entire working condition of a pumped storage power station: The pumped storage model test device in the present invention can detect the flow signal in real time and accurately adjust the flow size through the flow intelligent control module, set the cycle period, simulate the entire process of pumping, stilling and releasing water, and truly reflect the dynamic interaction between water and sand in the actual operation of the power station.

[0021] (3) Significant engineering application value: The pumped storage model test device in the present invention can guide the optimization of turbine selection, the formulation of sediment control strategies and the selection of pumping timing by analyzing the influencing factors of sediment content in the turbine and their quantitative relationship, providing a scientific basis for the safe operation of pumped storage power stations in sediment-rich basins.

[0022] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the overall structure of an embodiment of a pumped storage model test device capable of measuring sediment content passing through a machine and a test method thereof; Figure 2 Schematic diagram of the structure of the forebay and the model lower reservoir in an embodiment of the pumped storage model test device and test method capable of measuring sediment content passing through the machine according to the present invention; Figure 3 Schematic diagram of the structure of the flow intelligent control module in the embodiment of the pumped storage model test device and test method capable of measuring the sediment content of the pumped storage model; Figure 4 This is a structural schematic diagram of a pumped storage model test device capable of measuring pumped sediment content and a test method thereof in an embodiment of the present invention.

[0024] Reference numerals 1. Model upper reservoir; 2. Model lower reservoir; 3. Forebay; 4. Water pipeline; 5. Load-bearing bracket; 6. Electromagnetic flowmeter; 7. First water pump; 8. Frequency converter; 9. Sediment content monitoring sensor; 10. Sediment sampling port; 11. PVC steel hose; 12. Support foot pad; 13. Agitation pump; 14. Infrared sand meter; 15. PLC controller; 16. Second water pump. DETAILED DESCRIPTION

[0025] The technical solution of the present invention is further described below with reference to the accompanying drawings and embodiments.

[0026] Unless otherwise defined, technical or scientific terms used in the present invention shall have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs.

[0027] like Figure 1 As shown, a pumped-storage model test apparatus capable of measuring sediment concentration in water passing through a pumped-storage system comprises a model upper reservoir 1, a model lower reservoir 2, and a forebay 3. A pumping module and a discharge module are located between the upper and lower reservoirs 1 and 2. Both the pumping and discharge modules consist of an intelligent flow control module and a sediment monitoring module. Sediment monitoring modules are located at both ends of the intelligent flow control module. Water pipelines 4 connect the intelligent flow control module and the sediment monitoring module, as well as the upper and lower reservoirs 1 and 2 to the sediment monitoring module.

[0028] The upper model reservoir 1 and the lower model reservoir 2 are adapted to the prototype reservoir and scaled down. The upper model reservoir 1 and the lower model reservoir 2 are both made of LLDPE.

[0029] like Figure 2 As shown, a sand outlet and a stirring pump 13 are provided in the forebay 3 , and the forebay 3 and the model lower reservoir 2 are connected in sequence via a first water pump 7 and a PVC steel hose 11 .

[0030] like Figure 3 As shown, the flow intelligent control module is composed of an electromagnetic flow meter 6, a PLC controller 15, a frequency converter 8, and a second water pump 16. Figure 4 As shown, the sediment monitoring module includes an infrared sand measuring instrument 14, a sediment content monitoring sensor 9, and a sediment sampling port 10. The sediment content monitoring sensor 9 is arranged on the inner wall of the water pipe 4 at both ends of the flow intelligent control module, and the sediment sampling port 10 is arranged on the outside of the water pipe 4 of the sediment content monitoring sensor 9.

[0031] The intelligent flow control module and the water pipeline 4 are connected via a socket-and-spigot joint, with the gap between them filled with adhesive. A PVC steel hose 11 is installed between the upper and lower reservoirs 1 and 2, respectively, and the water pipeline 4. The water pipeline 4 consists of a UPVC straight pipe and a UPVC 90-degree curved pipe, all of which are transparent and visible. The water pipeline 4, the intelligent flow control module, and the sediment monitoring module are all fixed to a load-bearing bracket 5. The bracket 5 has several adjustable support pads 12 at its base, each adjustable to a height of 10 cm.

[0032] In this example, the sand content is selected as 1.66 kg / m 3 , sediment particle size 0.09mm, inlet and outlet position 6.9cm, pumping time 19.2min, pumping flow 4.32m 3 / h, still water time 12min, discharge time 19.2min, discharge flow 5.76m 3 / h, cutting height 36.37cm, etc. are the model test conditions.

[0033] A pumped storage model test device and test method capable of measuring sediment content passing through a pumped storage unit include the following steps: Step S1: Making a test model and preliminary debugging: A. Based on the actual dimensions of a pumped-storage power station in a sediment-laden basin, a test model was constructed based on similarity criteria, including a model upper reservoir 1, a model lower reservoir 2, a forebay 3, a first water pump 7, and a water pipeline 4. Based on the actual pumping conditions of the pumped-storage power station, representative water and sediment conditions were determined and converted to the model test scale.

[0034] B. Based on the model test conditions, the correlation between the sand content of the machine and the above variables was explored by adjusting the independent variables. In this example, the sand content was selected as 1.66 kg / m 3 Comparative sand content 0.83kg / m 3 The effect of a sediment particle size of 0.09 mm was used to compare the effect of a sediment particle size of 0.21 mm on the sediment content. The effect of a pumping time of 19.2 min was used to compare the effect of a pumping time of 9.6 min on the sediment content.

[0035] C. According to the model test conditions, determine the models of the flow intelligent control module, the electromagnetic flowmeter 6, the PLC controller 15, the frequency converter 8, the second water pump 16, the sediment content monitoring sensor 9, the infrared sand measuring instrument 14, etc. in the machine sediment monitoring module.

[0036] D. Program and debug the PLC controller 15 in the intelligent flow control module, converting the flow value from the electromagnetic flowmeter 6 into a standard process signal. This signal is then transmitted to the analog input module of the PLC controller 15 via a signal cable. The PLC controller 15 receives the real-time flow signal from the electromagnetic flowmeter 6, sets a target flow value according to a pre-programmed setting, compares it with a preset target flow setpoint, and performs calculations based on a pre-set PID (Proportional-Integral-Derivative) control algorithm to generate a corresponding control signal. This signal is then output to the inverter 8, which adjusts its output frequency. This signal drives the motor speed of the second water pump 16 to change accordingly, achieving dynamic control of the water flow rate.

[0037] E. Use water pipes 4 and PVC steel wire hoses 11 to connect various parts.

[0038] Step S2: according to the model test conditions, water is released into the model upper reservoir 1 to the dead water level.

[0039] Step S3: Determine the sediment content and total water volume of the model lower reservoir 2 according to the model test conditions, add water and sediment to the forebay 3 and stir until the sediment content reaches the test conditions, then enter the model lower reservoir 2 to conduct a pumping cycle test of the pumped storage power station.

[0040] Step S4: According to the model test conditions, the flow intelligent control module controls and sets the pumping flow and pumping time, still water time, discharge flow and discharge time, and the number of cycle cycles to simulate the entire process of pumping, still water, and discharge of a pumped storage power station.

[0041] Under the pumping condition, the second water pump 16 is activated to transport the sediment-laden water from the model lower reservoir 2 to the model upper reservoir 1 via the water pipeline 4. During this process, the pumping flow rate is dynamically adjusted by the frequency converter 8, the electromagnetic flowmeter 6 monitors the pipeline flow rate in real time, and the sediment concentration monitoring sensor 9 monitors the sediment concentration upstream and downstream of the pump. Under the discharge condition, the second water pump 16 is activated to transport the sediment-laden water from the model upper reservoir 1 to the model lower reservoir 2 via the water pipeline 4, and all the steps of the pumping condition are repeated. A cyclic "pumping-discharging" test is conducted according to the set model test conditions.

[0042] Step S5: Take water samples 5 times at equal intervals of one-fifth of the pumping and draining time at the sediment sampling ports 10 of the pumping model and the draining model, and mark the sampling time.

[0043] Step S6: Stir each water sample evenly and measure its sand content using a Model 3150 infrared sand detector 14, and compare, calibrate and verify the data with the sand content monitoring sensor 9.

[0044] Step S7: Establish a graph showing the change of sediment content at different times, and conduct a series of tests and quantitative research on the factors affecting the sediment content of the machine according to the model test conditions.

[0045] Conduct correlation analysis on the test data, generate two-dimensional curves (such as analyzing the relationship between sediment content and sediment content passing the pump), generate three-dimensional cloud maps (such as analyzing the relationship between pumping flow rate, pumping time and sediment content passing the pump), and establish an empirical regression model.

[0046] Therefore, the present invention adopts the above-mentioned pumped storage model test device and test method that can measure the sediment content of the pump passing through the machine. From the perspective of model testing, the sediment content of the pump passing through the machine is measured in real time according to the operating conditions of the pumped storage power station, and its response changes to different water and sediment conditions are examined, providing a scientific basis for the safe operation of the water pump and the optimization of the sediment control strategy, thereby solving the problem of insufficient monitoring and understanding of the sediment content of the pump passing through the machine during the actual operation of the pumped storage power station in the existing technology.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solutions of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A pumped storage model test device capable of measuring sediment content passing through a pumped storage system, characterized in that: It includes a model upper reservoir, a model lower reservoir, and a forepool. A pumping model and a water discharge model are set between the model upper reservoir and the model lower reservoir; the pumping model and the water discharge model are composed of a flow intelligent control module and a passing machine sediment monitoring module; both ends of the flow intelligent control module are equipped with a passing machine sediment monitoring module; the flow intelligent control module and the passing machine sediment monitoring module, as well as the model upper reservoir and the model lower reservoir and the passing machine sediment monitoring module are connected by water pipelines.

2. The pumped storage model test device capable of measuring sediment content according to claim 1, characterized in that: The upper model reservoir and the lower model reservoir are adapted to the shape of the prototype reservoir and are scaled down; the upper model reservoir and the lower model reservoir are both made of LLDPE.

3. The pumped storage model test device capable of measuring sediment content according to claim 1, characterized in that: A sand port and a stirring pump are provided in the forebay, and the forebay and the reservoir under the model are connected in sequence through a first water pump and a PVC steel wire hose.

4. The pumped storage model test device capable of measuring sediment content according to claim 1, characterized in that: The flow intelligent control module consists of an electromagnetic flowmeter, a PLC controller, a frequency converter, and a second water pump. The sediment monitoring module includes an infrared sand meter, a sediment content monitoring sensor, and a sediment sampling port. The sediment content monitoring sensor is installed on the inner wall of the water pipe at both ends of the flow intelligent control module, and the sediment sampling port is located outside the water pipe of the sediment content monitoring sensor. The flow intelligent control module and the water delivery pipeline are connected through a socket-and-spigot connection, and the gap between the two is filled with adhesive.

5. The pumped storage model test device capable of measuring sediment content according to claim 4, characterized in that: PVC steel wire hoses are installed between the model upper reservoir, the model lower reservoir and the water supply pipeline; the water supply pipeline includes UPVC straight pipes and UPVC 90-degree arc elbows.

6. The pumped storage model test device capable of measuring sediment content according to claim 5, characterized in that: The water supply pipeline, flow intelligent control module, and sediment monitoring module are all fixed on the load-bearing bracket. Several supporting pads are provided at the bottom of the load-bearing bracket, and the adjustable height of the supporting pads is 10 cm.

7. The test method of the pumped storage model test device capable of measuring sediment content according to any one of claims 1 to 6, characterized in that: The following steps are involved: Step S1: according to the model test conditions, water is released into the model upper reservoir to the dead water level; Step S2: Determine the sediment content of the model lower reservoir and the total amount of water to be pumped based on the model test conditions, add water and sediment to the forebay and stir until the sediment content reaches the test conditions, and then start the test after entering the model lower reservoir; Step S3: According to the model test conditions, the flow intelligent control module controls the pumping flow, pumping time, still water time, discharge flow, discharge time, and number of cycles to simulate the entire process of pumping, still water, and discharge of a pumped storage power station; Step S4: Take water samples five times at equal intervals of one-fifth of the pumping time and the discharge time at the sediment sampling ports of the pumping model and the discharge model, and mark the sampling time. Step S5: Stir each of the water samples evenly and measure the sediment content using an infrared sand meter, and compare, calibrate, and verify the data with the sediment content monitoring sensor; Step S6: Establish a graph showing the change of sediment content at different times, and conduct a series of tests and quantitative research on the factors affecting the sediment content of the machine according to the model test conditions.

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