Water pump and water pump station experimental teaching comprehensive platform and use method thereof

Abstract

This invention discloses a comprehensive experimental teaching platform for water pumps and pumping stations and its usage method. The platform consists of a closed-loop water circulation system, a multi-mode water pump unit, a long-distance pipeline transient flow simulator, a pipeline topology automatic reconstruction system, and a central control and acquisition system. It automatically and seamlessly switches between single pump, series-parallel, and water hammer demonstration loops by controlling an electrically controlled ball valve through a pre-stored valve opening and closing timing matrix. It also integrates a distributed pressure sensor array and an electrically controlled fast-closing valve to synchronously capture water hammer transient pressure waveforms at a sampling rate of no less than 1000Hz. This invention uses a closed-loop calibration unit to proportionally calculate the out-of-tolerance data deviating from the rated speed online, ensuring the comparability of data under multiple speed conditions. Simultaneously, it supports the installation of water hammer protection equipment for scientific research experiments and automatically calculates quantitative indicators such as pressure reduction rate and decay time. This integrated experimental teaching function, from steady-state performance testing to transient flow dynamic demonstration, is achieved on a single device.

Description

Technical Field

[0001] This invention relates to the field of experimental teaching technology in water conservancy engineering and water supply and drainage science and engineering, and in particular to a comprehensive experimental teaching platform for water pumps and pumping stations and its usage method. Background Technology

[0002] In experimental teaching for majors such as Water Supply and Drainage Science and Engineering, Environmental Engineering, and Agricultural Irrigation Engineering, single-function pump test benches or simple piping devices are mostly used to complete basic experiments for pump and pumping station courses. These traditional devices are generally equipped with only a single pump and basic piping. The flow rate is adjusted by manual valves and read by pointer instruments to complete basic experimental content such as understanding the structure of centrifugal pumps and measuring the head and efficiency of a single pump.

[0003] First, single-pump experimental platforms, due to their simple pipeline layout and lack of long-distance water transmission pipeline simulation units, exhibit hydraulic characteristics that differ significantly from the transient flow characteristics of pipelines in actual engineering pumping station systems. Students find it difficult to understand the operating state of pumps in real pipe networks and the mechanism of water hammer phenomena through such devices. Second, separating different experimental projects into multiple independent devices not only results in large laboratory footprints and high equipment purchase and maintenance costs, but more seriously, the lack of hydraulic linkage and data correlation between the devices leads to fragmented experimental knowledge for students, preventing them from establishing a complete pumping station system concept from the pump itself to the pipe network. Third, existing devices generally employ manual valve switching and manual recording of instrument readings, making experimental operations cumbersome, data acquisition inefficient, and prone to human error. This is particularly problematic for millisecond-level transient pressure processes like water hammer, where traditional pointer instruments are completely unable to capture their dynamic changes. Fourth, traditional experimental models primarily focus on verification operations, lacking the ability to cultivate research capabilities into complex engineering problems such as the overall operation and scheduling of pumping station systems, multi-pump linkage mechanisms, and water hammer protection strategies. This fails to meet the current requirements of universities for cultivating innovative applied talents.

[0004] Therefore, in response to the problems mentioned above, this invention proposes a comprehensive experimental teaching platform for water pumps and pumping stations, and its usage method. Summary of the Invention

[0005] To overcome the problems of existing experimental devices having separate functions, low system integration, disconnect from actual pump station engineering structures, inability to conduct integrated multi-condition experiments, and difficulty in dynamically demonstrating transient flow processes, this invention proposes a comprehensive experimental teaching platform for pumps and pumping stations that integrates a multi-mode pump unit, a long-distance pipeline simulator, and an automated measurement and control system, along with its usage method. This platform enables the completion of various teaching experiments on a single platform, including pump structure recognition, single pump and series-parallel performance testing, variable speed regulation characteristic analysis, and demonstration of water hammer phenomena in water pipelines. It also supports the automatic capture and recording of transient pressure waveforms.

[0006] The technical solution of this invention is: a comprehensive experimental teaching platform for water pumps and pumping stations, comprising: A closed-loop water circulation system includes an inlet tank, an outlet tank, a suction pipe, and an outlet pipe; The multi-mode water pump unit is connected between the suction pipe and the discharge pipe. It includes at least two centrifugal pumps and their independently driven frequency converters. Each centrifugal pump has a combined pressure measurement unit consisting of a pressure transmitter and a vacuum transmitter installed independently at its inlet and outlet ends. A long-distance pipeline transient flow simulator has an inlet connected to an outlet pipe and an outlet connected to an inlet tank. The simulator includes a 1000m calibrated pressure pipeline assembled from standard segments, a distributed pressure sensor array arranged at equal or non-equal intervals along the pipeline length, an electrically controlled quick-closing valve integrated at the pipeline end or key nodes, and replaceable pipeline feature modules located at reserved interfaces on the standard segments. The electrically controlled quick-closing valve is equipped with a servo motor and an angle encoder for precise control and recording of the valve closing speed at millisecond levels. The replaceable pipeline feature modules contain detachable test pipe segments with different roughnesses, diameters, or internal components simulating local water loss. Furthermore, the distributed pressure sensor array has densely packed measuring points upstream, inside, and downstream of this module. The pipeline topology automatic reconfiguration system includes multiple electrically controlled ball valves installed at key connection nodes and valve sequence controllers connected to their control terminals. The electrically controlled ball valves are full-bore electric ball valves equipped with opening feedback potentiometers. The valve sequence controller has a pre-stored valve opening and closing timing matrix corresponding to different experimental projects, which is used to automatically generate and execute valve configuration switching in response to experimental commands, thereby reconfiguring the fluid topology of the water circulation system, and switching between single pump loops, series pump loops, parallel pump loops and water hammer demonstration loops. Furthermore, the valve sequence controller controls some valves used to simulate water hammer protection conditions to close at preset multi-level stepped speeds, thereby generating different water hammer excitation waveforms. The multi-level stepped speeds include rapid full-range closure, two-stage fast and slow closure, and exponential rate closure. The central control and data acquisition system includes: The data acquisition module is connected to the feedback terminals of the distributed pressure sensor array, electromagnetic flow meter, torque and speed meter and each frequency converter, and is used to synchronously acquire transient pressure, steady-state pressure, flow rate, shaft power and speed data; The closed-loop calibration unit is connected to the data acquisition module, the electromagnetic flowmeter, and the torque tachometer, respectively. It is used to perform dynamic deviation compensation based on the real-time speed feedback of the frequency converter and the measured value of the torque tachometer, and to perform online conversion and calibration of performance test data that deviate from the rated speed by more than a preset threshold according to the proportional law. The experiment management unit is used to store the valve opening and closing timing matrix, receive the experiment items selected by the user and issue execution instructions to the valve sequence controller, and simultaneously set the sampling frequency and acquisition channel of the data acquisition module. The pump group control mode generator automatically calculates and generates the target frequency sequence of each frequency converter according to the experimental projects issued by the experimental management unit. The target frequency sequence follows the constraint relationship of the pump proportional law, thereby realizing the shock-free speed matching during the series-parallel switching process of multiple pumps. The water hammer event capture and analysis module is directly connected to the output of the distributed pressure sensor array and the action trigger signal of the electrically controlled quick-closing valve. This module includes: A synchronous trigger is used to initiate high-voltage capture at a sampling rate of not less than 1000Hz simultaneously with the issuance of a command to close the electrically controlled fast-closing valve; A dynamic pressure envelope generator is used to generate maximum and minimum pressure envelopes in real time based on the collected transient pressure data. The automatic repeating excitation unit is used to automatically change the closing speed or stroke of the electronically controlled fast-closing valve after a single water hammer event ends, and cyclically collect multiple sets of data until the preset closing speed range is covered.

[0007] This invention proposes a method for using a comprehensive experimental teaching platform for water pumps and pumping stations, comprising the following steps: S1, the target experimental project is selected and confirmed by the experimental management unit, and the experimental management unit automatically retrieves the corresponding valve opening and closing timing matrix and sends it to the valve sequence controller; S2, the valve sequence controller executes matrix instructions to automatically drive the corresponding electrically controlled ball valves and electrically controlled quick-closing valves to the target open and closed state, completes the experimental pipeline topology reconstruction, and feeds back a status confirmation signal; S3, the pump group control mode generator generates the initial frequency of each frequency converter according to the experimental project and starts the multi-mode water pump unit. During operation, according to the preset working condition adjustment strategy, the platform enters and stabilizes at the target experimental working condition by adjusting the frequency converter frequency or adjusting the opening of a specific electrically controlled ball valve. S4. After the system stabilizes, the central control and data acquisition system synchronously triggers the data acquisition module according to the predefined measurement points and parameter list of the experimental project. It collects steady-state or transient experimental data from the distributed pressure sensor array, electromagnetic flowmeter, torque tachometer and frequency converter feedback terminal. The closed-loop calibration unit performs real-time deviation compensation and conversion on the collected data based on the current speed. S5. For water hammer demonstration experiments, the central control and data acquisition system controls the electrically controlled fast-closing valve to close at a preset speed to trigger water hammer through the water hammer event capture and analysis module. It also automatically records transient pressure data from the pre-trigger stabilization period to the post-trigger oscillation decay process at a sampling rate of not less than 1000Hz and plots the water hammer pressure envelope. For performance experiments, the central control and data acquisition system automatically adjusts the flow regulating valve to multiple different openings, collects steady-state data point by point, and calculates the head, shaft power, and efficiency online based on the collected data, and generates a family of performance curves in real time. S6. All raw data and calculation results are stored in the experimental management unit, and an electronic experimental report containing pipeline topology diagrams, key parameter variation curves, and analysis conclusions is generated.

[0008] As a preferred embodiment, when conducting basic performance or variable speed performance tests on centrifugal pumps, the valve sequence controller automatically closes the loop isolation valve on the simulator to short-circuit the transient flow simulator of the long-distance pipeline according to the pre-stored single-pump performance test matrix, and opens the bypass circulation valve. Under the control of the frequency converter, the data acquisition module makes the pump run at the rated speed and at least 3 different speeds. At each speed, the flow rate is adjusted 13 times from fully closed to fully open by adjusting the opening of the outlet solenoid ball valve. After each 2-minute settling period to allow the water flow to stabilize, no less than 12 sets of experimental data are collected. Each set of data simultaneously records the flow rate, head, shaft power, and speed under the operating condition. When the closed-loop calibration unit determines that the deviation between the actual speed and the target speed exceeds ±1%, it automatically converts all test point data to the rated speed according to the proportional law formula and then uses it for performance curve fitting. When conducting centrifugal pump series-parallel experiments, the valve sequence controller automatically reconstructs the pipeline connection relationship of the two pumps according to the series experiment matrix or the parallel experiment matrix. At the moment of switching between series and parallel operating conditions, the pump group control mode generator adopts a speed control strategy based on feedforward compensation: first, the speed of the two pumps is synchronously adjusted to the calculated speed that matches the target operating condition after the switch through the frequency converter, and then the series or parallel topology configuration of the valves is switched to avoid secondary water hammer impact caused by abrupt changes in pipeline topology. When conducting scientific research experiments on water hammer protection equipment, the water hammer protection equipment to be tested (air valve, water hammer eliminator, or pressure regulating well model) is first installed on the reserved quick interface of the long-distance pipeline transient flow simulator. Then, the protection equipment evaluation mode is selected in the experimental management unit. The central control and data acquisition system automatically executes the standard water hammer generation procedure. Specifically, the electrically controlled quick-closing valve is controlled to close at the rated speed, and the baseline water hammer curve without protection is recorded through a distributed pressure sensor array. Then, under the same initial conditions, the water hammer event is repeatedly triggered but the protection equipment is activated, and the pressure decay curve after protection is recorded. The water hammer event capture and analysis module automatically calculates the maximum pressure reduction rate, pressure fluctuation decay time, and absolute value of minimum negative pressure in the pipeline under the action of the protection equipment, and generates a comparative data report.

[0009] The beneficial effects of this invention are: 1. This invention integrates a multi-mode water pump unit, a long-distance pipeline transient flow simulator, and a pipeline topology automatic reconstruction system, and pre-stores various valve opening and closing timing matrices. All experiments, including single pump performance, series and parallel performance, variable speed performance, and water hammer demonstration, can be seamlessly carried out on a single platform through automatic configuration switching of the electronically controlled valve sequence controller. There is no need to replace pipelines or multiple sets of discrete equipment. This solves the problems of functional separation, low experimental efficiency, and fragmented system cognition in existing devices, and greatly improves the systematicness and convenience of experimental teaching.

[0010] 2. This invention introduces a pressure pipeline with a calibrated length of 1000m, a distributed pressure sensor array, and an electrically controlled fast-closing valve into the experimental platform, along with a water hammer event capture and analysis module. It can synchronously trigger and capture the entire process of water hammer transient pressure at a sampling rate of no less than 1000Hz, and automatically generate a dynamic pressure envelope. This allows students to intuitively observe the propagation, reflection, and attenuation laws of pressure waves, overcoming the problem that traditional devices cannot demonstrate and record millisecond-level transient flow processes. This makes experimental teaching truly close to the transient hydraulic characteristics of actual pumping station engineering.

[0011] 3. This invention, by equipping a closed-loop calibration unit, reads the actual speed fed back by the torque tachometer in real time and compares it with the inverter's set value. For operating data that deviates from the rated speed by more than ±1%, it automatically performs online conversion according to the proportional law, ensuring the comparability and accuracy of experimental data of different speeds and different batches. At the same time, it adopts a full-bore electrically controlled ball valve with an opening feedback potentiometer, which supports multi-stage stepped speed closing of the valve to generate a controllable water hammer excitation waveform, greatly improving the reliability and repeatability of experimental data.

[0012] 4. In addition to meeting the basic teaching and experimental needs, this invention can also be used to carry out scientific research experiments by connecting with protective equipment such as air valves and water hammer eliminators through the reserved quick interface. The water hammer event capture and analysis module automatically calculates quantitative indicators such as the maximum pressure reduction rate, pressure fluctuation decay time and minimum negative pressure absolute value and generates comparative reports, realizing the dual value of teaching and scientific research. Moreover, the entire platform has a high degree of automation and is safe and reliable, and has good prospects for promotion in related professional laboratories of similar colleges and universities. Attached Figure Description

[0013] Figure 1 The diagram shown is a schematic representation of the overall structure of the present invention. Detailed Implementation

[0014] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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 some embodiments of the present invention, but 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.

[0015] Please see Figure 1 The present invention provides an embodiment: In this embodiment, a closed-loop water circulation system is described, specifically: The experimental teaching platform of this invention adopts a closed-loop water circulation design. Its closed-loop water circulation system includes an inlet tank, an outlet tank, a suction pipe, and an outlet pipe, effectively avoiding water waste during experiments while ensuring the stability of the inlet water head. A multi-mode water pump unit is located between the inlet and outlet tanks, comprising two centrifugal pumps. Each centrifugal pump is equipped with an independently driven frequency converter, and each centrifugal pump has a combined pressure measurement unit consisting of a pressure transmitter and a vacuum transmitter installed independently at its inlet and outlet ends. This design allows the platform to operate independently with a single pump, or in series or parallel operation between two pumps. Furthermore, the frequency converter can steplessly adjust the pump speed, thus covering the entire operating range of the centrifugal pump's proportional control adjustment.

[0016] In this embodiment, a transient flow simulator for a long-distance pipeline is described, specifically: The long-distance pipeline transient flow simulator has an inlet connected to an outlet pipe and an outlet connected to an inlet tank. Its main body is a 1000m long pressure pipeline assembled from standard segments. Distributed pressure sensor arrays, consisting of multiple high-frequency response pressure transmitters, are evenly spaced along the pipeline length, enabling real-time monitoring of steady-state and transient pressure waves at different cross-sections of the pipeline. Electrically controlled fast-closing valves are integrated at the pipeline's end or key nodes. These valves are equipped with servo motors and angle encoders, allowing for precise control and recording of valve closing speeds at the millisecond level. Closing times can be set to multiple levels, such as 0.1 seconds, 0.5 seconds, and 1.0 seconds. The actual angle change curve at each closing speed is fed back to the control system in real-time by the encoder. Simultaneously, a replaceable pipe feature module is installed at the reserved interface of the standard section. This module can be detachably fitted with test pipe sections of different roughness (Manning coefficients 0.012, 0.016, 0.020), different diameters (50% reduction, 120% expansion), or those containing simulated local water loss components (90° elbows, sudden expansion, half-open gates, etc.). Upstream, inside, and downstream of this replaceable pipe feature module, a dense network of pressure measuring points is set to collect data on local hydraulic losses and pressure fluctuation attenuation as fluid passes through different pipe features. This allows students to intuitively understand the physical meaning and measurement method of the local resistance coefficient.

[0017] This embodiment describes the automatic pipeline topology reconfiguration system, specifically: The automatic pipeline topology reconfiguration system comprises multiple electrically controlled ball valves deployed at key connection nodes and a valve sequence controller connected to their control terminals. All these electrically controlled ball valves are full-bore electric ball valves equipped with opening feedback potentiometers. Therefore, the valves can not only achieve two-position control (fully open or fully closed), but also arbitrarily set their opening degree within the range of 0% to 100%, thus simulating local resistance at different valve opening degrees. The valve sequence controller pre-stores valve opening and closing timing matrices corresponding to different experimental projects, including single-pump basic performance experimental matrices, series performance experimental matrices, parallel performance experimental matrices, single-pump water hammer demonstration matrices, and series-parallel water hammer demonstration matrices. When the operator selects an experimental project through the experimental management unit, the valve sequence controller automatically parses the corresponding timing matrix and sequentially drives the corresponding electrically controlled ball valves and electrically controlled quick-closing valves according to the preset order and time intervals, thereby completing the topology reconfiguration of the entire experimental pipeline without relying on manual valve operation. This automatic reconfiguration has a response time of less than 30 seconds, which is much faster than the traditional manual pipe disassembly and replacement method, and has excellent repeatability, eliminating the risk of human error.

[0018] For some valves used to simulate water hammer protection conditions, the valve sequence controller can control them to close at preset multi-level stepped speeds, including but not limited to rapid full-stroke closure (simulating extreme water hammer excitation), two-stage fast and slow closure (first closing 80% of the stroke quickly and then slowly closing the remaining 20%, simulating the closing law of actual water hammer protection valves), and exponential rate closure (simulating the transient flow boundary conditions of valves closing according to an exponential curve), thereby generating water hammer excitation sources with different waveform characteristics, providing controllable input conditions for the study of water hammer protection mechanisms.

[0019] In this embodiment, the central control and data acquisition system will be described in detail: The central control and data acquisition system includes a data acquisition module, a closed-loop calibration unit, an experimental management unit, a pump control mode generator, and a water hammer event capture and analysis module. The data acquisition module is connected to the feedback terminals of the distributed pressure sensor array, electromagnetic flowmeter, torque and tachometer, and each frequency converter, and can synchronously acquire five major parameters: transient pressure, steady-state pressure, flow rate, shaft power, and speed.

[0020] The sampling strategy of this module automatically switches according to the experiment type, specifically: When conducting steady-state performance experiments, the sampling frequency is set to 1-10Hz. After continuously collecting data for 30 seconds at each steady-state operating point, the average value is taken as the data for that point. During the water hammer demonstration experiment, the sampling frequency was automatically switched to no less than 1000Hz to meet the requirement of capturing transient pressure waveforms without distortion.

[0021] The closed-loop calibration unit is connected to the data acquisition module, electromagnetic flowmeter, and torque tachometer. Its core function is to monitor the actual speed fed back by the frequency converter and the shaft speed measured by the torque tachometer in real time. When the deviation between the two exceeds a preset threshold (±1%), it automatically applies the centrifugal pump proportional law formula: ; The flow rate, head, and shaft power data collected under operating conditions deviating from the rated speed are converted to their corresponding values ​​at the rated speed, so that the performance curves at different speeds can be plotted on the same graph for comparative analysis.

[0022] The experimental management unit is responsible for storing the valve opening and closing timing matrix, receiving the experimental projects selected by the user, issuing execution instructions to the valve sequence controller, and simultaneously configuring the sampling frequency and acquisition channel of the data acquisition module.

[0023] The pump control mode generator automatically calculates and generates the target frequency sequence for each frequency converter based on the experimental items (series mode and parallel mode) issued by the experimental management unit. This sequence strictly follows the constraints of the pump proportional law. For example, before starting in series, the frequencies of the two pumps are made the same to ensure flow matching; before starting in parallel, the frequencies of the two pumps are adjusted to make their heads approximately equal, thereby achieving shock-free speed matching during the switching process of multiple pumps in series and parallel, and avoiding secondary pressure fluctuations caused by sudden changes in flow or head.

[0024] The water hammer event capture and analysis module is directly connected to the action trigger signal of the electrically controlled fast-closing valve and the output of the distributed pressure sensor array. It includes a synchronous trigger, a dynamic pressure envelope generator, and an automatic repetitive excitation unit. The synchronous trigger ensures that high-pressure data capture is initiated at a sampling rate of no less than 1000Hz simultaneously with the issuance of the electrically controlled fast-closing valve closing command. The dynamic pressure envelope generator plots the upper and lower envelopes of pressure changes over time in real time based on the acquired transient pressure data, using different colors to indicate the maximum positive pressure and minimum negative pressure. The automatic repetitive excitation unit can automatically change the closing speed or stroke of the electrically controlled fast-closing valve after a single water hammer event, cyclically collecting multiple sets of data until all preset closing speed ranges are covered, thus efficiently completing the experiment on the influence of valve closing speed on the peak water hammer pressure.

[0025] This invention provides an embodiment: Before any experiment begins, the system forces a platform initialization self-check process. The central control and data acquisition system sequentially sends query commands to all electrically controlled ball valves, electrically controlled quick-closing valves, frequency converters, pressure sensors, and flow meters. Each queried component, upon receiving the command, returns its unique identifier (ID) and current status information (current valve opening, current frequency converter frequency, whether the sensor output value is within the range, etc.). The system's internal device topology map pre-stores the IDs, physical locations, and interconnections of all components. The returned information is matched and verified against the device topology map item by item. If an ID is not returned or the returned status is abnormal, the abnormal node is highlighted on the human-machine interface of the experiment management unit, and specific fault prompts are generated. Simultaneously, any experiment is prohibited from starting until the fault is resolved.

[0026] This example illustrates the basic performance and variable speed performance experiments of a centrifugal pump, specifically: This embodiment is used to determine the head, shaft power, and efficiency of a single centrifugal pump under different flow conditions, plot the performance curves at rated speed and variable speed, and verify the proportional law.

[0027] First, the operator selects the centrifugal pump basic performance experiment on the human-machine interface of the experimental management unit. The system automatically retrieves the corresponding valve opening and closing timing matrix (single pump performance experiment matrix). After receiving the instruction, the valve sequence controller executes the following valve actions: closing valves 5, 6, 9, and 10, automatically closing the loop isolation valve on the simulator to short-circuit the long-distance pipeline transient flow simulator (allowing the effluent to return directly to the inlet tank via a bypass, avoiding excessive friction resistance from the 1000m long pipeline), simultaneously opening the bypass circulation valve, and keeping the inlet valve connecting the second pump in the suction pipeline closed. The entire valve action process is completed within 20 seconds. The pipeline topology diagram is updated synchronously on the experimental management unit interface, with green and red indicating the open and closed valves respectively, making it easy for students to intuitively understand the current water flow path.

[0028] Then, the pump control mode generator generates the initial frequency of the first centrifugal pump's inverter at 50Hz (rated frequency) according to the preset "single pump" mode, and starts the pump. After the pump runs stably (about 30 seconds), students adjust the opening of the outlet electric ball valve through the experimental management unit, from fully closed (0% opening) to fully open (100% opening) in 13 steps (based on experience that the centrifugal pump performance curve requires 10-15 discrete points for smooth fitting) to adjust the flow rate. After each valve opening adjustment, the system automatically settles for 2 minutes to allow the water flow to transition from transient to steady state. This settling time is based on the fact that after the 1000m long pipeline is short-circuited, the hydraulic inertia of the remaining pipeline is relatively small, and 2 minutes is sufficient to reduce the pressure fluctuation to within ±0.5% of the steady-state value. At each steady-state operating point, the data acquisition module continuously collects data for 30 seconds at a sampling frequency of 10Hz. The collected parameters include the pump inlet vacuum gauge reading, the pump outlet pressure gauge reading, the instantaneous flow rate of the electromagnetic flowmeter, and the shaft power and actual speed measured by the torque tachometer. The arithmetic mean of all data points collected within 30 seconds is taken as the representative value for that operating condition.

[0029] After collecting data at 13 operating points at rated speed, the experimental management unit prompts "Whether to conduct a speed change performance test?" If "Yes" is selected, the system automatically generates a frequency sequence for the frequency converter (40Hz, 60Hz (if the frequency converter supports overclocking) or a safe 45Hz, 55Hz, etc.) according to the requirement of "at least 3 different speeds." At each speed, the above 13 valve opening adjustment and data acquisition processes are repeated. When the frequency converter's set frequency deviates from 50Hz, the actual speed will have a slight deviation from the theoretical synchronous speed due to factors such as slip. Simultaneously, the closed-loop calibration unit will read the actual speed value fed back by the torque tachometer in real time and compare it with the theoretical speed corresponding to the frequency converter's set frequency. If the absolute value of the deviation between the actual speed and the target speed exceeds ±1%, the closed-loop calibration unit automatically calls the formula based on the proportional law to calculate the flow rate, head, and shaft power data for all 13 operating points at the same speed, and uniformly corrects them to the theoretical speed corresponding to that set frequency. If the actual rotational speed is 1480 rpm (theoretical rated speed is 1500 rpm) and the deviation is -1.33%, then the system will multiply the measured flow rate Q by (1500 / 1480) and the head H by (1500 / 1480). 2 Shaft power P multiplied by (1500 / 1480) 3 This allows us to obtain the equivalent value at the rated speed. This online calibration function ensures good comparability between different batches of experimental data, even when the inverter control accuracy is limited or the power grid frequency fluctuates. Students can clearly see the proportional law relationship of the performance curves at different speeds.

[0030] Finally, the experimental management unit automatically plots the head (H)-flow rate (Q) curve, shaft power (P)-flow rate (Q) curve, and efficiency (η)-flow rate (Q) curve based on the converted data. For the variable speed performance experiment, the HQ curves at multiple speeds are plotted on the same coordinate graph and distinguished by different colors. Students can visually verify the proportionality law by observing the relationship between head and speed at the same flow rate. All raw data and calculation results are automatically stored, and an electronic experimental report is generated that includes the experimental objective, pipeline topology diagram, raw data table, conversion process explanation, and performance curve graphs.

[0031] This example illustrates the performance test of two centrifugal pumps connected in series. Specifically: This embodiment is used to study the total head characteristics and flow matching relationship of two centrifugal pumps of the same model running in series, and compares and analyzes them with the performance curve of a single pump.

[0032] After the operator selects the series performance experiment, the valve sequence controller calls the corresponding series experiment matrix and automatically closes the relevant valves, so that the connection between the two pumps is as follows: the outlet of the first pump is directly connected to the inlet of the second pump, and the outlet of the second pump is then connected to the outlet pipeline. Specifically, under the valve numbering scheme of this platform, the controller automatically closes valves 2, 6, 7, 9, and 10, and opens other necessary valves to form a series water supply system. This process is fully automated and requires no manual adjustment of any pipeline joints.

[0033] The pump control mode generator employs a speed control strategy based on feedforward compensation. Before series startup, the speeds of the two pumps are synchronized to the calculated speed matching the target operating condition after switching via a frequency converter. Since the two pumps are of the same model, the target speed is set to the same 50Hz. Then, the two pumps are started simultaneously to enter the operating state in parallel. In series operation, the system adjusts the flow rate 13 times by regulating the opening of the main outlet valve. At each operating point, the data acquisition module simultaneously collects the inlet and outlet pressures of the first pump, the inlet and outlet pressures of the second pump, the electromagnetic flowmeter reading of the main pipe, and the shaft power and speed of each pump. Based on the collected data, the total head and total efficiency of the series system can be calculated.

[0034] After the experiment, the experimental management unit automatically plotted the HQ curve of the series operation and displayed it on the same coordinate graph as the HQ curve of a single pump.

[0035] This example illustrates a water hammer demonstration experiment for water pipelines. Specifically: This embodiment uses a water hammer demonstration in a water pipeline during single-pump operation as an example for illustration.

[0036] The operator selects the single-pump water hammer demonstration experiment in the experimental management unit. The valve sequence controller calls the corresponding water hammer experiment matrix and automatically closes valves 5, 6, 7, and 8, making the water flow path as follows: outlet tank, water pump, 1000m long pipeline, end-point electrically controlled quick-closing valve, and inlet tank. This pipeline layout retains the complete 1000m pressure pipeline to observe the propagation and reflection of pressure waves in the long pipeline.

[0037] Start a single water pump and gradually open the pump outlet valve to full opening. Once the water flow in the pipeline stabilizes, the experimental management unit will display "System stabilized". At this point, the water hammer event capture and analysis module is in a pending state.

[0038] Students use the "Trigger Water Hammer" button on the experiment management unit interface to set the closing speed parameters of the electrically controlled fast-closing valve. For example, selecting "Fast Closing" sets the valve's time from fully open to fully closed to 0.2 seconds. Upon clicking "Trigger," the synchronous trigger immediately starts data acquisition from all distributed pressure sensors and the pressure sensor at the end of the pipeline at a sampling rate of 1000Hz. Simultaneously, the servo motor drives the electrically controlled fast-closing valve to close according to the set speed curve. The angle encoder provides real-time feedback on the valve's actual angular position, aligned with the time axis. During valve closure, the water flow velocity in the pipeline rapidly drops to zero, converting kinetic energy into pressure energy, forming a pressure rise wave. This pressure wave propagates upstream along the pipeline at approximately 1000m / s, reflects as a pressure drop wave upon reaching the inlet tank, and then returns to the valve, causing subsequent oscillation attenuation.

[0039] A distributed pressure sensor array simultaneously records pressure changes over time at multiple cross-sections along the pipeline. The dynamic pressure envelope generator in the water hammer event capture and analysis module processes this data in real time, automatically identifying the maximum positive pressure, maximum negative pressure, and pressure wave arrival time at each measuring point. Data from all measuring points is integrated into a complete pressure envelope diagram along the pipeline, with the horizontal axis representing pipeline length (0-1000m) and the vertical axis representing pressure. The diagram simultaneously displays the maximum positive pressure line and the minimum negative pressure line.

[0040] The experiment can be repeated. Each time the closing speed of the electrically controlled quick-closing valve is changed, the automatic repeat excitation unit will automatically execute in sequence until all water hammer waveforms at the preset speeds have been collected. The system finally generates a comparison chart showing the changing trend of the maximum water hammer pressure at the valve end under different closing speeds.

[0041] This example illustrates a scientific research experiment on water hammer protection equipment. Specifically: Researchers installed the water hammer protection devices (air valves, water hammer eliminators, or surge tank models) to be tested on a pre-reserved quick-connect interface of a long-distance pipeline transient flow simulator. This interface is located near the end of the pipeline because the maximum positive pressure of water hammer usually occurs at the valve, and the protection devices are often located nearby. The installation process uses a flange or clamp quick-connect method without modifying the original pipeline.

[0042] In the experimental management unit, select "Protective Equipment Evaluation Mode" and the system will automatically execute the standardized water hammer generation procedure.

[0043] The first round of testing was an unprotected benchmark test: the electrically controlled quick-closing valve was controlled to perform a quick-closing action at the rated speed (1.0 second closing time). The distributed pressure sensor array recorded the entire process of pressure fluctuations at each cross-section of the pipeline. The water hammer event capture and analysis module automatically calculated the peak pressure, pressure rise rate, and oscillation duration of the benchmark water hammer.

[0044] The second round of testing involved a comparative test with the protective equipment activated: under identical initial conditions (pump speed, valve closing speed), a water hammer event was triggered again. This time, the installed air valve would automatically draw in and replenish air when the pressure inside the pipe was lower than atmospheric pressure, or the water hammer eliminator would absorb the pressure wave through a piston or diaphragm. The system recorded the pressure curve after protection.

[0045] The water hammer event capture and analysis module automatically performs multiple quantitative comparative analyses: calculating the maximum pressure reduction rate under the action of protective equipment (baseline peak value). The pressure fluctuation decay time (the time elapsed from the trigger moment until the pressure fluctuation peak drops to within ±5% of the stable pressure) is calculated using the formula (peak value after protection / baseline peak value × 100%). The absolute value of the minimum negative pressure appearing in the pipeline is also recorded (the smaller the negative pressure value, the greater the risk of vaporization and the worse the protection effect). These indicators are presented on the interface in numerical and bar chart form, and a research experiment report is generated, including a superimposed graph of the baseline curve and the peak value after protection, and a comparison table of key indicators.

[0046] The table below shows some key data recorded in a water hammer protection experiment:

[0047] As shown in the table above, researchers can quantitatively evaluate the protective effect of the water hammer eliminator, thus providing experimental basis for equipment selection in engineering applications. This function makes this platform not only a teaching tool, but also a general test bench for water hammer protection technology research.

[0048] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments that can be applied to other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A water pump and water pump station experiment teaching comprehensive platform, characterized in that, Including: A closed-loop water circulation system includes an inlet tank, an outlet tank, a suction pipe, and an outlet pipe; A multi-mode water pump unit, connected between the suction pipe and the discharge pipe, includes at least two centrifugal pumps and their independently driven frequency converters; A long-distance pipeline transient flow simulator has an inlet connected to an outlet pipe and an outlet connected to an inlet tank. The simulator includes a 1000m long pressure pipeline, a distributed pressure sensor array arranged at equal or non-equal intervals along the pipeline length, and an electrically controlled fast-closing valve integrated at the end of the pipeline or a key node. The electrically controlled fast-closing valve is equipped with a servo motor and an angle encoder to achieve precise control and recording of the valve closing speed at the millisecond level. The pipeline topology automatic reconfiguration system includes: Multiple electrically controlled ball valves are installed at key connection nodes of the multi-mode water pump unit, the long-distance pipeline transient flow simulator, and the closed-loop water circulation system. The valve sequence controller is connected to the control terminals of multiple electrically controlled ball valves and electrically controlled fast-closing valves. The controller has a pre-stored valve opening and closing timing matrix corresponding to different experimental projects. It is used to generate and execute valve configuration switching in response to experimental commands, and to reconstruct the fluid topology of the water circulation system. This allows switching between single pump circuit, series pump circuit, parallel pump circuit and water hammer demonstration circuit without physically replacing the pipeline. The central control and data acquisition system includes: The data acquisition module is connected to the feedback terminals of the distributed pressure sensor array, electromagnetic flow meter, torque and speed meter and each frequency converter, and is used to synchronously acquire transient pressure, steady-state pressure, flow rate, shaft power and speed data; The closed-loop calibration unit is connected to the data acquisition module, electromagnetic flowmeter and torque tachometer respectively. It is used to perform dynamic deviation compensation based on the real-time speed feedback of the frequency converter and the measured value of the torque tachometer, and to perform online conversion and calibration of performance test data that deviate from the rated speed by more than a preset threshold according to the proportional law. The experiment management unit is used to store the valve opening and closing timing matrix, receive the experiment items selected by the user and issue execution instructions to the valve sequence controller, and simultaneously set the sampling frequency and acquisition channel of the data acquisition module.

2. The experimental teaching comprehensive platform of water pump and water pump station according to claim 1, characterized in that: Each centrifugal pump in the multi-mode pump unit is independently equipped with a combined pressure measurement unit at its inlet and outlet ends. This combined pressure measurement unit includes a pressure transmitter and a vacuum transmitter. The central control and data acquisition system also includes a pump control mode generator. This generator calculates and generates the target frequency sequence for each frequency converter based on the experimental projects issued by the experimental management unit. This target frequency sequence follows the constraint relationship of the pump proportional law, thereby achieving shock-free speed matching during the series-parallel switching process of multiple pumps.

3. The experimental teaching comprehensive platform of water pump and water pump station according to claim 1, characterized in that: The long-distance pipeline transient flow simulator also includes a replaceable pipeline feature module, which is located at a reserved interface in the pressure pipeline. The module contains test pipe sections with different roughness, different diameters, or built-in components simulating local water loss. The distributed pressure sensing array has encrypted measuring points upstream, inside and downstream of the replaceable pipeline feature module to collect data on local hydraulic loss and pressure fluctuation attenuation when the fluid passes through different pipeline features.

4. The experimental teaching comprehensive platform of water pump and water pump station according to claim 1, characterized in that: The electrically controlled ball valve in the pipeline topology automatic reconfiguration system is a full-bore electric ball valve, equipped with an opening feedback potentiometer. When the valve sequence controller executes the valve opening and closing timing matrix, for the valves used to simulate water hammer protection conditions, it controls the valves to close at a preset multi-level stepped speed to generate different water hammer excitation waveforms. The multi-level stepped speed includes rapid full-range closing, two-stage fast and slow closing, and exponential rate closing.

5. The experimental teaching comprehensive platform of water pump and water pump station according to claim 1, characterized in that: The central control and data acquisition system also includes a water hammer event capture and analysis module. This water hammer event capture and analysis module is connected to the action trigger signal of the electronically controlled fast-closing valve and the output end of the distributed pressure sensor array. The water hammer event capture and analysis module includes a synchronous trigger, a dynamic pressure envelope generator, and an automatic repetitive excitation unit. The synchronous trigger is used to start high pressure capture at a sampling rate of not less than 1000Hz at the same time as issuing the closing command of the electrically controlled fast-closing valve; the dynamic pressure envelope generator is used to generate the maximum or minimum pressure envelope in real time based on the collected transient pressure data; the automatic repetitive excitation unit is used to change the closing speed or stroke of the electrically controlled fast-closing valve after a single water hammer event ends, and to collect multiple sets of data in a loop until the preset closing speed range is covered.

6. A method for using a water pump and water pump station experimental teaching comprehensive platform, for using the water pump and water pump station experimental teaching comprehensive platform in any one of claims 1-5, characterized in that, Includes the following steps: S1, the experimental management unit of the central control and data acquisition system selects and confirms the target experimental project, and the experimental management unit retrieves the corresponding valve opening and closing timing matrix and sends it to the valve sequence controller. S2, the valve sequence controller executes matrix instructions to drive the corresponding electrically controlled ball valves and electrically controlled quick-closing valves to the target open and closed state, completes the experimental pipeline topology reconstruction, and feeds back a status confirmation signal; S3, the pump group control mode generator generates the initial frequency of each frequency converter according to the experimental project and starts the multi-mode water pump unit. During operation, according to the preset working condition adjustment strategy, the system enters and stabilizes at the target experimental working condition by adjusting the frequency converter frequency or adjusting the opening of a specific electrically controlled ball valve. S4. After the system stabilizes, the central control and data acquisition system synchronously triggers the data acquisition module according to the predefined measurement points and parameter list of the experimental project. It collects steady-state or transient experimental data from the distributed pressure sensor array, electromagnetic flowmeter, torque tachometer and frequency converter feedback terminal. The closed-loop calibration unit performs real-time deviation compensation and conversion on the collected data based on the current speed. S5, for water hammer demonstration experiments, the central control system controls the electronically controlled fast-closing valve to close at a preset speed to trigger water hammer through the water hammer event capture and analysis module, and records transient pressure data from the pre-triggered stabilization period to the post-triggered oscillation decay process at a high sampling rate, and plots the water hammer pressure envelope; for performance experiments, the central control and data acquisition system adjusts the flow regulating valve to multiple different openings, collects steady-state data point by point, and calculates the head, shaft power and efficiency online based on the collected data, and generates a family of performance curves in real time; S6. All raw data and calculation results are stored in the experimental management unit, and an electronic experimental report containing pipeline topology diagrams, key parameter variation curves, and analysis conclusions is generated.

7. The use method of the water pump and water pump station experimental teaching comprehensive platform according to claim 6, characterized in that: When conducting basic performance or variable speed performance tests on centrifugal pumps, the valve sequence controller, based on the pre-stored single-pump performance test matrix, closes the loop isolation valve on the simulator to short-circuit the transient flow simulator of the long-distance pipeline and opens the bypass circulation valve. Under the control of the frequency converter, the data acquisition module makes the pump run at the rated speed and at least three different speeds. At each speed, by adjusting the opening of the outlet solenoid ball valve, at least 12 sets of experimental data are collected evenly from fully closed to fully open. The closed-loop calibration unit judges the deviation between the actual speed and the target speed in real time. When it exceeds ±1%, all test point data are converted to the rated speed according to the proportional law formula and then used for performance curve fitting. Each set of experimental data simultaneously records the flow rate, head, shaft power, and speed under that operating condition.

8. The use method of the water pump and water pump station experimental teaching comprehensive platform according to claim 6, characterized in that: When conducting a series-parallel centrifugal pump experiment, the valve sequence controller reconstructs the pipeline connection relationship of the two pumps based on the series experiment matrix or the parallel experiment matrix. At the moment of switching between series and parallel operating conditions, the pump group control mode generator adopts a speed control strategy based on feedforward compensation.

9. The method of using the integrated experimental teaching platform for water pumps and pumping stations according to claim 8, characterized in that, The speed control strategy includes: first, adjusting the speed of the two water pumps synchronously to the calculated speed that matches the target operating condition after switching through the frequency converter, and then performing the series or parallel topology configuration switch of the valves to avoid secondary water hammer impact caused by the sudden change in pipeline topology.

10. The method of using the integrated experimental teaching platform for water pumps and pumping stations according to claim 6, characterized in that: When conducting scientific research experiments on water hammer protection equipment, the water hammer protection equipment to be tested is first installed on the reserved quick interface of the long-distance pipeline transient flow simulator. Then, the protection equipment evaluation mode is selected in the experimental management unit. At this time, the electrically controlled quick-closing valve is closed at the rated speed. The baseline water hammer curve without protection is recorded by the distributed pressure sensor array. Then, under the same initial conditions, the water hammer event is repeatedly triggered but the protection equipment is activated. The pressure decay curve after protection is recorded. At the same time, the water hammer event capture and analysis module calculates the maximum pressure reduction rate, pressure fluctuation decay time and minimum negative pressure absolute value of the pipeline under the action of the protection equipment, and generates a comparative data report. The water hammer protection equipment is an air valve, water hammer eliminator or pressure regulating well model.

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