A Solid-Liquid Mixed Pump Blockage Detection Experimental System and Intelligent Control Method

Abstract

This invention provides a solid-liquid mixed-transfer pump blockage detection experimental system and intelligent control method, relating to the field of solid-liquid mixed-transfer pump blockage detection technology. The system includes a variable frequency slurry pump, an inlet conveying pipeline, an outlet conveying pipeline, an inlet pressure transmitter, an outlet pressure transmitter, a third shut-off valve, a fourth shut-off valve, a frequency converter, a computer, cables, a signal transmission line, a mixing tank, and a storage tank. This invention arranges pressure transmitters and shut-off valves on both the inlet and outlet sides of the variable frequency slurry pump. By collecting pressure data and combining it with the proposed intelligent control method, the system comprehensively analyzes pipeline pressure fluctuations and pump speed changes to construct an accurate judgment of the pump's operating status. Based on this, the system can adaptively adjust the pump speed in real time, thereby achieving rapid response and proactive intervention in the early stages of blockage.

Description

Technical Field

[0001] This invention relates to the field of solid-liquid mixed-transfer pump blockage detection technology, and more particularly to a solid-liquid mixed-transfer pump blockage detection experimental system and intelligent control method. Background Technology

[0002] For deep-sea mining projects, pipeline-based ore transportation is currently the primary method. Mixed-flow pumps located on the pipeline power the solid-liquid two-phase flow, transporting ore particles from several kilometers underwater to the surface support platform. The long-term stable operation of the pump-pipeline system is a key factor for successful deep-sea mining. However, due to the long transport distances and large quantities of particles involved, blockages in the pump-pipeline system can occur, severely impacting mining operations. Furthermore, as the only moving component powering the solid-liquid two-phase flow, the mixed-flow pump is more prone to blockages.

[0003] Currently, there is limited application of intelligent regulation technology for mixed-transport pumps used in hydraulic lifting for deep-sea mining projects. Most anti-clogging technologies are primarily applied to land-based pumps such as diaphragm pumps, oil pumps, and dual-oil pumps used in 3D printing. If a pump becomes clogged, the system can automatically trigger a shutdown by monitoring abnormal changes in relevant parameters and arrange for manual maintenance. Domestic research has also been conducted on anti-clogging design for mixed-transport pumps used in deep-sea mining, mainly by changing structural parameters (e.g., impeller cross-sectional area) or operating conditions (e.g., flow rate, particle size, speed). However, due to the complex pump structure (usually composed of more than six impellers connected in series) and the harsh operating environment thousands of meters underwater, the probability of clogging increases, and immediate manual intervention is difficult once problems occur. Therefore, it is urgent to analyze the flow parameters within the pipeline to determine the pump's operating status in real time, thereby achieving intelligent regulation and minimizing losses as quickly as possible. Summary of the Invention

[0004] To address the aforementioned technical problems, a solid-liquid mixed pump blockage detection experimental system and intelligent control method are provided.

[0005] The technical means employed in this invention are as follows:

[0006] A solid-liquid mixing pump blockage detection experimental system includes: a variable frequency slurry pump, an inlet conveying pipe, an outlet conveying pipe, an inlet pressure transmitter, an outlet pressure transmitter, a third shut-off valve, a fourth shut-off valve, a frequency converter, a computer, cables, signal transmission lines, a mixing tank, and a storage tank. The inlet end of the variable frequency slurry pump is fixedly connected to one end of the inlet conveying pipe, and the outlet end is fixedly connected to one end of the outlet conveying pipe. The other end of the inlet conveying pipe is fixedly connected to the mixing tank, which contains a mixture of experimental particles and water. The other end of the outlet conveying pipe is connected to two passages, which are respectively suspended above the mixing tank and the storage tank. An inlet pressure transmitter and a third shut-off valve are installed on the inlet conveying pipe, and an outlet pressure transmitter and a fourth shut-off valve are installed on the outlet conveying pipe. Each pressure transmitter is connected to the computer via a signal transmission line. The variable frequency slurry pump is connected to the frequency converter via a cable, and the frequency converter is connected to the computer via a cable.

[0007] Furthermore, the inlet and outlet ends of the variable frequency slurry pump are fixedly connected to the inlet conveying pipeline and the outlet conveying pipeline, respectively, via flanges.

[0008] Furthermore, the mixing chamber has a stirring function.

[0009] Furthermore, the storage bin is equipped with a filter barrel inside.

[0010] Furthermore, a first shut-off valve and a second shut-off valve are fixedly installed on the two passages, respectively.

[0011] This invention also provides an intelligent control method, employing the above-mentioned solid-liquid mixed-transfer pump blockage detection experimental system, comprising the following steps: Step 1: Monitor the pressure values ​​of the inlet and outlet delivery pipelines in real time using the inlet pressure transmitter and the outlet pressure transmitter, which are the inlet pressure and the outlet pressure, respectively, and upload the monitoring data to the computer for synchronous processing. Step 2.1: When the inlet pressure and outlet pressure decrease relative to their respective normal operating pressure values, monitor the change in the speed of the variable frequency slurry pump over time and make a judgment based on the change in speed. Step 2.1.1: If the speed remains unchanged, it indicates that the inlet is blocked. The computer issues a command to control the frequency converter to adjust the speed of the variable frequency slurry pump to 0 within 5 seconds to achieve emergency shutdown. Step 2.1.2: If the speed decreases, it indicates that the blades of the variable frequency slurry pump are blocked; the computer extracts the data of the motor output current and speed and makes a judgment. Step 2.1.2.1: If the speed drops below the critical speed and the output current still exceeds 10% of the rated current, the computer will issue a command to control the frequency converter to adjust the speed of the variable frequency slurry pump to 0 to achieve shutdown. Step 2.1.2.2: If the speed drops to above the critical speed and the output current is less than 10% of the rated current, then run at this speed for 1 minute and readjust the variable frequency slurry pump speed to the working speed, and monitor the current at this time. Step 2.1.2.2.1: If the current is still greater than 10% of the rated current, the blockage has not been relieved. Then, the computer sends a command to control the frequency converter to adjust the speed of the variable frequency slurry pump to 0 to achieve shutdown. Step 2.1.2.2.2: If the current is less than 10% of the rated current, it indicates that the blockage has been relieved and normal operation can continue. Step 2.2: When both the inlet and outlet pressures increase, it indicates that the variable frequency slurry pump outlet is blocked. The computer sends a command to the frequency converter to reduce the speed of the variable frequency slurry pump and continuously monitors the outlet pressure of the outlet delivery pipeline. Step 2.2.1: If the outlet pressure value still exceeds the normal operating pressure fluctuation range, continue to reduce the speed of the variable frequency slurry pump; Step 2.2.2: If the outlet pressure drops to within the normal operating pressure fluctuation range, extract the speed data of the variable frequency slurry pump; Step 2.2.2.1: If the current speed of the variable frequency slurry pump is less than the critical speed, it must be stopped within 5 seconds. Step 2.2.2.2: If the speed of the variable frequency slurry pump is greater than the critical speed, the computer sends a command to the frequency converter to adjust the speed to the maximum speed and work for 5 seconds, then reduce it to the working speed and extract the outlet pressure value. Step 2.2.2.2.1: If the outlet pressure value still exceeds the normal operating pressure fluctuation range, shut down the machine immediately within 5 seconds. Step 2.2.2.2.2: If the outlet pressure value is within the normal operating pressure fluctuation range, it indicates that the blockage has been cleared and the system continues to operate.

[0012] Furthermore, in step 2.1.2.2, the operating speed is the speed set at the beginning of the experiment when no blockage occurs.

[0013] Furthermore, in steps 2.2.1, 2.2.2, 2.2.2.2.1 and 2.2.2.2.2, the normal operating pressure is the actual pressure value reached in the outlet delivery pipeline when the variable frequency slurry pump reaches its operating speed.

[0014] Furthermore, in step 2.1.2.1, the critical speed is the speed at which the solid-liquid two-phase flow in the pipeline is just able to be transported along the circulating experimental pipeline; if the speed is lower than the critical speed, the particles will not be transported into the mixing box and the storage box.

[0015] Furthermore, in step 2.2.2.2, the maximum speed is the speed that the motor itself can reach when the output current is controlled within a certain range for safe operation, which is greater than the operating speed.

[0016] Compared with the prior art, the present invention has the following advantages: 1. The solid-liquid mixed-transfer pump blockage detection experimental system provided by this invention can realize various different blockage conditions by manually controlling the shut-off valve, and extract the corresponding pressure characteristics, thus correlating the blockage condition with pressure changes. Based on this, in actual operation, the blockage state of the pump pipe can be quickly and accurately deduced solely from the pressure characteristics.

[0017] 2. This invention proposes an intelligent control method that comprehensively analyzes pipeline pressure fluctuations and mixed-transfer pump speed changes for different blockage states, constructs a judgment of pump operating status, and realizes real-time adaptive adjustment of pump speed, thereby achieving rapid response and proactive intervention in the early stage of blockage.

[0018] 3. By combining the blockage detection experimental system proposed in this invention, the current intelligent control method can be further optimized to obtain the correspondence between pressure changes and blockage conditions. This allows for the direct judgment of various blockage conditions based on changes in inlet and outlet pressure values, thereby enabling rapid and accurate control.

[0019] Based on the above reasons, this invention can be widely applied in fields such as deep-sea mining. Attached Figure Description

[0020] 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 some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the experimental system of the present invention.

[0022] Figure 2 This is a flowchart of the intelligent control process of the present invention.

[0023] In the diagram: 1. Variable frequency slurry pump; 2.1. Inlet conveying pipeline; 2.2. Outlet conveying pipeline; 3.1. Inlet pressure transmitter; 3.2. Outlet pressure transmitter; 4.1. First shut-off valve; 4.2. Second shut-off valve; 4.3. Third shut-off valve; 4.4. Fourth shut-off valve; 5. Frequency converter; 6. Computer; 7. Cable; 8. Signal transmission line; 9. Mixing tank; 10. Storage tank; 11. Filter barrel; 12. Experimental particles. Detailed Implementation

[0024] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0025] 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 only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. 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.

[0026] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0027] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0028] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention. The directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0029] For ease of description, spatial relative terms such as "above," "over," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation besides the orientation of the device as described in the figures. For example, if the device in the figures is inverted, a device described as "above" or "above" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0030] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0031] Example 1 For deep-sea mining projects, pipeline-based ore transportation is still the primary method. Mixed-flow pumps located on the pipelines provide the power for the transmission of solid-liquid two-phase flow within the pipeline. However, clogging of the pump and pipeline system is one of the challenges encountered during transportation. Therefore, accurately determining whether pump blockage has occurred and taking correct operational measures to ensure operational safety is a core aspect of ensuring the stable operation of the system.

[0032] This invention proposes an experimental system for detecting blockages in solid-liquid mixed-transfer pumps, which is an experimental cyclic system for detecting pump blockages. Pressure transmitters and shut-off valves are respectively arranged on both the inlet and outlet sides of a variable frequency slurry pump 1 (mixed-transfer pump). By collecting pressure data and combining it with the proposed intelligent control method, the system comprehensively analyzes pipeline pressure fluctuations and changes in the pump's rotational speed to construct an accurate judgment of the pump's operating status. Based on this, the system can adaptively adjust the pump's rotational speed in real time, thereby achieving rapid response and proactive intervention in the early stages of blockage.

[0033] This invention discloses a solid-liquid mixing pump blockage detection experimental system, comprising a variable frequency slurry pump 1, an inlet conveying pipe 2.1, an outlet conveying pipe 2.2, an inlet pressure transmitter 3.1, an outlet pressure transmitter 3.2, a third shut-off valve 4.3, a fourth shut-off valve 4.4, a frequency converter 5, a computer 6, a cable 7, a signal transmission line 8, a mixing tank 9, and a storage tank 10. The inlet end of the variable frequency slurry pump 1 is fixedly connected to one end of the inlet conveying pipe 2.1, and the outlet end is fixedly connected to one end of the outlet conveying pipe 2.2; the other end of the inlet conveying pipe 2.1 is fixedly connected to the mixing tank 9, which contains experimental particles. The mixture of 12 and water has two passages connected to the other end of the outlet conveying pipe 2.2. The two passages are respectively suspended above the mixing tank 9 and the storage tank 10. An inlet pressure transmitter 3.1 and a third shut-off valve 4.3 are installed on the inlet conveying pipe 2.1, and an outlet pressure transmitter 3.2 and a fourth shut-off valve 4.4 are installed on the outlet conveying pipe 2.2. The two sets of pressure transmitters and shut-off valves are respectively close to the inlet and outlet of the variable frequency slurry pump 1. Each pressure transmitter is connected to the computer 6 through the signal transmission line 8. The variable frequency slurry pump 1 is connected to the frequency converter 5 through the cable 7, and the frequency converter 5 is connected to the computer 6 through the cable 7.

[0034] This invention also provides an intelligent control method, employing the above-mentioned solid-liquid mixed-transfer pump blockage detection experimental system, comprising the following steps: Step 1: Monitor the pressure values ​​of the inlet delivery pipeline 2.1 and the outlet delivery pipeline 2.2 in real time using the inlet pressure transmitter 3.1 and the outlet pressure transmitter 3.2, which are the inlet pressure and the outlet pressure, respectively, and upload the monitoring data to the computer 6 for synchronous processing.

[0035] Step 2.1: When the inlet pressure and outlet pressure decrease relative to their respective normal operating pressure values, monitor the change in the rotational speed of the variable frequency slurry pump 1 over time, and make a judgment based on the change in rotational speed.

[0036] Step 2.1.1: If the rotation speed remains unchanged, it indicates that the inlet is blocked. The computer 6 issues a command to control the frequency converter 5 to adjust the rotation speed of the variable frequency slurry pump 1 to 0 within 5 seconds to achieve emergency shutdown. The frequency converter 5 will then shut down the pump within 5 seconds.

[0037] Step 2.1.2: If the speed decreases, it indicates that the blades of the variable frequency slurry pump 1 are blocked. The computer 6 extracts the data of the motor output current and speed and makes a judgment.

[0038] Step 2.1.2.1: If the speed drops below the critical speed and the output current still exceeds 10% of the rated current, the computer 6 issues a command to control the frequency converter 5 to adjust the speed of the variable frequency slurry pump 1 to 0 to achieve shutdown.

[0039] Step 2.1.2.2: If the speed drops to above the critical speed and the output current is less than 10% of the rated current, then after running at this speed for 1 minute, readjust the speed of the variable frequency slurry pump 1 to the working speed and monitor the current at this time.

[0040] Step 2.1.2.2.1: If the current is still greater than 10% of the rated current, the blockage has not been relieved. Then, the computer 6 sends a command to control the frequency converter 5 to adjust the speed of the variable frequency slurry pump 1 to 0 to achieve shutdown. Step 2.1.2.2.2: If the current is less than 10% of the rated current, it indicates that the blockage has been relieved and normal operation can continue.

[0041] Step 2.2: When both the inlet and outlet pressures increase, it indicates that the outlet of the variable frequency slurry pump 1 is blocked. The computer 6 sends a command to the frequency converter 5 to reduce the speed of the variable frequency slurry pump 1 and continuously monitor the outlet pressure of the outlet delivery pipeline 2.2.

[0042] Step 2.2.1: If the outlet pressure value still exceeds the normal operating pressure fluctuation range, continue to reduce the speed of the variable frequency slurry pump 1.

[0043] Step 2.2.2: If the outlet pressure value drops to within the normal operating pressure fluctuation range, extract the speed data of variable frequency slurry pump 1.

[0044] Step 2.2.2.1: If the current speed of the variable frequency slurry pump 1 is less than the critical speed, it must be stopped within 5 seconds. After stopping, manual intervention is required to alleviate the blockage, such as disassembling the original equipment.

[0045] Step 2.2.2.2: If the speed of the variable frequency slurry pump 1 is greater than the critical speed, the computer 6 sends a command to the frequency converter 5 to adjust the speed to the maximum speed and work for 5 seconds, then reduce it to the working speed and extract the outlet pressure value.

[0046] Step 2.2.2.2.1: If the outlet pressure value still exceeds the normal operating pressure fluctuation range, shut down the machine within 5 seconds.

[0047] Step 2.2.2.2.2: If the outlet pressure value is within the normal operating pressure fluctuation range, it indicates that the blockage has been cleared and the system continues to operate.

[0048] Example 2 like Figure 1 As shown, the solid-liquid mixing pump blockage detection experimental system of the present invention includes a variable frequency slurry pump 1, an inlet conveying pipe 2.1, an outlet conveying pipe 2.2, an inlet pressure transmitter 3.1, an outlet pressure transmitter 3.2, four shut-off valves, a frequency converter 5, a computer 6, a cable 7, a signal transmission line 8, a mixing tank 9, a storage tank 10, a filter barrel 11, and experimental particles 12. The four shut-off valves are respectively the first shut-off valve 4.1, the second shut-off valve 4.2, the third shut-off valve 4.3, and the fourth shut-off valve 4.4.

[0049] The inlet and outlet ends of the variable frequency slurry pump 1 are fixedly connected to the inlet conveying pipe 2.1 and the outlet conveying pipe 2.2 via flanges, respectively. The inlet conveying pipe 2.1 is fixedly connected to the mixing tank 9. Pressure transmitters and shut-off valves are fixedly installed on both the inlet conveying pipe 2.1 and the outlet conveying pipe 2.2. Specifically, the inlet conveying pipe 2.1 is equipped with an inlet pressure transmitter 3.1 and a third shut-off valve 4.3 located near the inlet of the variable frequency slurry pump 1, and the outlet conveying pipe 2.2 is equipped with an outlet pressure transmitter 3.2 and a fourth shut-off valve 4.4 located near the outlet of the variable frequency slurry pump 1.

[0050] The mixing chamber 9 is used to mix water and experimental particles 12. It has a stirring function (an existing type of stirrer can be installed inside). During the experiment, continuous stirring can prevent particles from agglomerating in the chamber and causing blockage.

[0051] The inlet conveying pipe 2.1 and the outlet conveying pipe 2.2 are used to convey the mixture of liquid and experimental particles 12.

[0052] Two pressure transmitters are used to monitor the pressure changes of the inlet delivery pipeline 2.1 connected to the inlet of the variable frequency slurry pump 1 and the outlet delivery pipeline 2.2 connected to the outlet.

[0053] The third shut-off valve 4.3 and the fourth shut-off valve 4.4 are used to block the inlet conveying pipe 2.1 and the outlet conveying pipe 2.2, respectively, to regulate pipe blockage. When the third shut-off valve 4.3 on the inlet conveying pipe 2.1 is closed, an inlet blockage condition can be simulated; when the fourth shut-off valve 4.4 on the outlet conveying pipe 2.2 is closed, an outlet blockage condition can be simulated. In engineering, when transporting mixtures of solid particles and liquids in pipelines, a certain degree of blockage can occur. For example, as the mixture enters the pump from the pipeline, the width of the path it travels changes. If the initial content of solid particles in the mixture is relatively high, it may cause blockage at the pump inlet; while blockage at the pump outlet is partly due to the settling of solid particles in the mixture, which accumulate at the pump outlet, causing blockage. Therefore, this invention, by installing shut-off valves and closing the corresponding valves, can artificially block the inlet and outlet pipes to verify the feasibility of the control strategy of this invention.

[0054] The storage tank 10 can be placed next to the mixing tank 9. The filter barrel 11 is installed inside the storage tank 10 to achieve solid-liquid separation. This is used to calculate the flow parameters of the solid-liquid two-phase flow (liquid and particles) and the volume fraction (concentration) of the experimental particles 12.

[0055] At the end of the outlet conveying pipe 2.2, two shut-off valves (first shut-off valve 4.1 and second shut-off valve 4.2) form two passages. The first shut-off valve 4.1 and the second shut-off valve 4.2 are installed on two separate passages, which are suspended above the mixing tank 9 and the storage tank 10, respectively. The solid-liquid mixture conveyed by the outlet conveying pipe 2.2 can be directed to the storage tank 10 by adjusting the shut-off valve above the mixing tank 9, for calculating the volume fraction of the experimental particles 12. At the start of the experiment, the first shut-off valve 4.1 is open and the second shut-off valve 4.2 is closed. After the pump starts, the solid-liquid two-phase flow begins to circulate in the pipeline system. After running for a period of time, such as 1 minute, the first shut-off valve 4.1 is closed and the second shut-off valve 4.2 is opened simultaneously for 3 seconds. After 3 seconds, the first shut-off valve 4.1 is opened again and the second shut-off valve 4.2 is closed simultaneously. The experimental system returns to its initial state, and the mass of water in the storage tank 10 and the mass of particles in the filter tank 11 can be calculated to obtain the flow rate and solid volume fraction.

[0056] The frequency converter 5 is connected to the motor of the variable frequency slurry pump 1 and the computer 6 via cable 7, and is used to control the motor speed.

[0057] The imported pressure transmitter 3.1 and the exported pressure transmitter 3.2 transmit electrical signals to the computer 6 via signal transmission line 8.

[0058] Computer 6 is used to write intelligent control strategies, that is, to use C language to write intelligent control strategies, collect signals from each pressure transmitter and frequency converter 5 and process them (including motor speed, output current and pipeline pressure).

[0059] The experimental system of this invention, through multiple shut-off valves installed at the inlet and outlet of a variable frequency slurry pump, can actively simulate various clogging conditions, including: complete inlet blockage, complete outlet blockage, incomplete inlet blockage, incomplete outlet blockage, and simultaneous blockage at both inlet and outlet. By simulating these different blockage states, the dynamic changes in inlet and outlet pressures of the solid-liquid mixing pump (variable frequency slurry pump) under various operating conditions are extracted, establishing a mapping relationship between pressure response patterns and blockage types. Based on this, a basis can be provided for quickly identifying and judging blockage states solely based on pressure characteristics during actual operation.

[0060] For example: I. Normal operating condition reference state When the circulation system is operating normally, the fourth shut-off valve 4.4, the third shut-off valve 4.3, and the first shut-off valve 4.1 are all open, while the second shut-off valve 4.2 is closed. At this time, the solid-liquid two-phase flow within the pipeline is stable, and the pressure signals collected by the inlet pressure transmitter 3.1 (pump inlet) and the outlet pressure transmitter 3.2 (pump outlet) remain relatively stable within a certain normal fluctuation range. All pressure data can be read in real time by the computer 6 and plotted as a pressure-time curve, serving as a reference for subsequent blockage detection.

[0061] II. Simulation of Complete Blockage at the Inlet Based on the stable operation of the system, the third shut-off valve 4.3 is manually and slowly adjusted until it is completely closed to simulate a scenario where the pump inlet pipeline is completely blocked.

[0062] Inlet pressure (inlet pressure transmitter 3.1): As the third shut-off valve 4.3 gradually closes, the fluid source at the pump inlet is cut off, and the inlet pressure continuously decreases from the normal operating value, eventually approaching 0 (gauge pressure). The rate of pressure decrease is positively correlated with the valve closing speed.

[0063] Outlet pressure (outlet pressure transmitter 3.2): In the initial stage of the inlet pressure drop, the outlet pressure may fluctuate briefly or drop slightly because the residual fluid in the pump body is still being discharged; after the inlet pressure drops to close to 0, the pump will "dry run" or "evacuate" because it cannot suck in the medium, and the outlet pressure will drop significantly.

[0064] On the pressure-time curve, the characteristic of "inlet pressure decreasing first → outlet pressure decreasing later → both eventually approaching zero" is observed, with the starting point of the inlet pressure decrease significantly earlier than the starting point of the outlet pressure decrease. Therefore, the mapping relationship between pressure response and blockage type can be obtained: if the inlet pressure decreases first and the outlet pressure decreases later, it indicates blockage in the inlet pipeline.

[0065] III. Simulation of Complete Outlet Blockage Based on the stable operation of the system, the fourth shut-off valve 4.4 is manually and slowly adjusted until it is completely closed to simulate a scenario where the pump outlet pipeline is completely blocked.

[0066] Outlet pressure (outlet pressure transmitter 3.2): As the fourth shut-off valve 4.4 gradually closes, the fluid passage after the pump outlet is blocked, the pump discharge resistance increases sharply, and the outlet pressure continues to rise from the normal operating value, eventually possibly approaching the pressure value corresponding to the pump's maximum head.

[0067] Inlet pressure (inlet pressure transmitter 3.1): In the initial stage of the outlet pressure rise, since the pump is still running and the outlet is blocked, the pump's operating point moves along the performance curve towards low flow and high head, and the inlet pressure shows a slight increase or increased pulsation; if it continues to run, the pump may increase the current due to overload, and the inlet pressure will also increase accordingly.

[0068] The pressure-time curve exhibits a characteristic of "outlet pressure rising first, followed by a slight increase in inlet pressure," with the starting point of the outlet pressure increase slightly earlier than that of the inlet pressure increase. Therefore, a mapping relationship between the pressure response pattern and the blockage type can be derived: a pattern of outlet pressure rising first, followed by inlet pressure increase, indicates blockage in the outlet pipeline.

[0069] The working principle of the experimental system of this invention: 1. Simulate blockage scenarios, extract pressure characteristics, and verify control strategies. During the blockage study, the second shut-off valve 4.2 was always closed, and the first shut-off valve 4.1 was always open.

[0070] (1) The inlet is completely blocked First, add sufficient water to the mixing tank 9. Then, use the computer 6 to control the frequency converter 5 to adjust the speed of the variable frequency slurry pump 1 to its operating speed and allow it to run stably for a period of time. Manually adjust the third shut-off valve 4.3 until it is completely closed, simulating a scenario where the pump inlet pipeline is completely blocked. The inlet pressure (inlet pressure transmitter 3.1) continuously decreases from its normal operating value, eventually approaching 0 (gauge pressure). The outlet pressure (outlet pressure transmitter 3.2) may experience brief fluctuations or a slight decrease; once the inlet pressure drops to near 0, the outlet pressure decreases significantly. The pressure-time curve is processed and displayed in real time by the computer 6.

[0071] After detecting the corresponding pressure change characteristics, the speed of the variable frequency slurry pump 1 is monitored over time. If the speed remains unchanged, it indicates that the inlet is blocked. The computer 6 issues a command to control the frequency converter 5 to adjust the speed of the variable frequency slurry pump 1 to 0 to achieve emergency shutdown.

[0072] If the speed decreases, it indicates that the blades of the variable frequency slurry pump 1 are blocked. The computer 6 sends a command to the frequency converter 5 to further reduce the speed of the variable frequency slurry pump 1, thereby reducing the pump's output current. If the speed decreases below the critical speed and the output current exceeds 10% of the rated current, the computer 6 sends a command to control the frequency converter 5 to adjust the speed of pump 1 to 0, thus stopping the pump. If the speed decreases above the critical speed and the output current is less than 10% of the rated current, the pump is run at this speed for 1 minute, and then the speed of the variable frequency slurry pump 1 is readjusted to the operating speed, and the current is monitored. If the current is still greater than 10% of the rated current, the blockage has not been relieved, and the computer 6 sends a command to control the frequency converter 5 to adjust the speed of pump 1 to 0, thus stopping the pump. If the current is less than 10% of the rated current, it indicates that the blockage has been relieved, and normal operation can continue.

[0073] (2) The outlet is completely blocked. A new set of experiments is started, and the variable frequency slurry pump 1 is put into operation. At this point, both the third shut-off valve 4.3 and the fourth shut-off valve 4.4 are open. The fourth shut-off valve 4.4 is manually adjusted until it is completely closed, simulating a scenario where the pump outlet pipeline is completely blocked. As the fourth shut-off valve 4.4 gradually closes, the outlet pressure (outlet pressure transmitter 3.2) continuously rises from its normal operating value. The inlet pressure (inlet pressure transmitter 3.1) initially shows a slight increase or increased pulsation during the initial rise in outlet pressure; if operation continues, the inlet pressure also increases. The computer 6 sends a command to the frequency converter 5 to reduce the speed of the variable frequency slurry pump 1 and continuously monitors the outlet pressure of the outlet delivery pipeline 2.2 until the outlet pressure decreases to the operating pressure. If the current speed of the variable frequency slurry pump 1 is less than the critical speed, it indicates that the outlet is completely blocked. The computer 6 then sends a command to control the frequency converter 5 to adjust the speed of the variable frequency slurry pump 1 to 0, thus stopping the pump.

[0074] (3) The outlet was blocked and then cleared. The process of clearing blockages is achieved by manually adjusting the fourth shut-off valve 4.4, opening and closing it repeatedly. Specifically: Unlike a complete blockage at the outlet, a partial blockage only requires partially closing the fourth shut-off valve 4.4, while real-time monitoring of outlet pressure changes. As the fourth shut-off valve 4.4 gradually closes, the outlet pressure (outlet pressure transmitter 3.2) continuously rises from its normal operating value. The computer 6 sends a command to the frequency converter 5 to reduce the speed of the variable frequency slurry pump 1 and continuously monitors the outlet pressure of the outlet delivery pipeline 2.2 until the outlet pressure decreases to the working pressure. The pump speed at this point is compared. If the speed of the variable frequency slurry pump 1 is greater than the critical speed, the computer 6 sends a command to the frequency converter 5 to adjust the speed to the maximum speed and operate for 5 seconds before reducing it to the working speed, and the outlet pressure value is extracted. This adjustment process aims to increase the flow rate in the pipeline in a short time, intending to break up the blockage. Simultaneously, the fourth shut-off valve 4.4 is manually fully opened to simulate the state of the blockage being cleared. Finally, the pressure that is increased and then reduced to the working speed has the same fluctuation range as the working pressure, indicating that the blockage has been cleared and the equipment can continue to operate.

[0075] II. Flow Measurement During flow measurement, both the fourth shut-off valve 4.4 and the third shut-off valve 4.3 remain open. Initially, the first shut-off valve 4.1 is open, and the second shut-off valve 4.2 is closed. Sufficient water and experimental particles 12 are first added to the mixing tank 9. The variable frequency slurry pump 1 is adjusted to its operating speed using the frequency converter 5 controlled by the computer 6 and run stably for a period of time. Then, the first shut-off valve 4.1 is manually closed and the second shut-off valve 4.2 is opened simultaneously, allowing the solid-liquid two-phase flow to enter the storage tank 10 and the filter tank 11. The opening time of the second shut-off valve 4.2 is recorded, such as 3s / 5s. After this measurement period, the second shut-off valve 4.2 is closed and the first shut-off valve 4.1 is opened simultaneously, allowing the solid-liquid two-phase flow to re-enter the mixing tank 9. The mass of the liquid in the storage tank 10 and the mass of the particles in the filter tank 11 are measured respectively to obtain the particle volume fraction and flow parameters during the measurement period.

[0076] To address the problem of blockage in pump pipeline systems, this invention also provides an intelligent control method that uses the aforementioned experimental system to achieve real-time adjustment of a variable frequency slurry pump (mixed transport pump).

[0077] Step 1: Monitor the pressure values ​​of the inlet delivery pipeline 2.1 and the outlet delivery pipeline 2.2 in real time using the inlet pressure transmitter 3.1 and the outlet pressure transmitter 3.2, which are the inlet pressure and the outlet pressure, respectively, and upload the monitoring data to the computer 6 for synchronous processing.

[0078] Step 2.1: When the inlet pressure and outlet pressure decrease relative to their respective normal operating pressure (i.e., pressure when not blocked), monitor the change in the rotational speed of the variable frequency slurry pump 1 over time, and make a judgment based on the change in rotational speed.

[0079] Step 2.1.1: If the rotational speed remains unchanged, it indicates an inlet blockage. The computer 6 issues a command to control the frequency converter 5 to adjust the rotational speed of the variable frequency slurry pump 1 to 0 within 5 seconds to achieve an emergency shutdown. After shutdown, manual intervention can be used to disconnect the pipeline from the pump inlet flange and clean the inlet.

[0080] Step 2.1.2: If the speed decreases, it indicates that the blades of the variable frequency slurry pump 1 are blocked. The computer 6 extracts the data of the motor output current and speed and makes a judgment.

[0081] Step 2.1.2.1: If the speed drops below the critical speed and the output current still exceeds 10% of the rated current, the computer 6 issues a command to control the frequency converter 5 to adjust the speed of the variable frequency slurry pump 1 to 0 to achieve shutdown.

[0082] The critical speed is the speed at which the solid-liquid two-phase flow is just able to be transported along the circulating experimental pipeline. Below the critical speed, the experimental particles 12 will not be transported into the mixing tank 9 and the storage tank 10.

[0083] Step 2.1.2.2: If the speed drops to above the critical speed and the output current is less than 10% of the rated current, then after running at this speed for 1 minute, readjust the speed of the variable frequency slurry pump 1 to the working speed and monitor the current at this time.

[0084] The operating speed was the speed set at the beginning of the experiment when no blockage occurred.

[0085] Step 2.1.2.2.1: If the current is still greater than 10% of the rated current, the blockage has not been relieved. Then, the computer 6 sends a command to control the frequency converter 5 to adjust the speed of the variable frequency slurry pump 1 to 0 to achieve shutdown. Step 2.1.2.2.2: If the current is less than 10% of the rated current, it indicates that the blockage has been relieved and normal operation can continue.

[0086] Step 2.2: When both the inlet and outlet pressures increase, it indicates that the outlet of the variable frequency slurry pump 1 is blocked. The computer 6 sends a command to the frequency converter 5 to reduce the speed of the variable frequency slurry pump 1 and continuously monitor the outlet pressure of the outlet delivery pipeline 2.2.

[0087] Step 2.2.1: If the outlet pressure value still exceeds the normal operating pressure fluctuation range, continue to reduce the speed of the variable frequency slurry pump 1.

[0088] Step 2.2.2: If the outlet pressure value drops to within the normal operating pressure fluctuation range, extract the speed data of variable frequency slurry pump 1.

[0089] The normal operating pressure is the actual pressure value reached in the outlet conveying pipeline 2.2 when the variable frequency slurry pump 1 reaches its operating speed.

[0090] Step 2.2.2.1: If the current speed of the variable frequency slurry pump 1 is less than the critical speed, it must be stopped within 5 seconds. After stopping, manual intervention is required to alleviate the blockage, such as disassembling the original equipment.

[0091] Step 2.2.2.2: If the speed of the variable frequency slurry pump 1 is greater than the critical speed, the computer 6 sends a command to the frequency converter 5 to adjust the speed to the maximum speed and work for 5 seconds, then reduce it to the working speed and extract the outlet pressure value.

[0092] The maximum speed is the speed that the motor can reach when the output current is controlled within a certain range for safe operation, and it is greater than the working speed (the working speed is greater than the critical speed).

[0093] Step 2.2.2.2.1: If the outlet pressure value still exceeds the normal operating pressure fluctuation range, shut down the machine within 5 seconds.

[0094] Step 2.2.2.2.2: If the outlet pressure value is within the normal operating pressure fluctuation range, it indicates that the blockage has been cleared and the system continues to operate. That is, repeat steps 1 to 2.2.2.2.2 to continue monitoring (the strategy of this invention is always running when the control system interlock is opened).

[0095] Furthermore, when the operating speed of the variable frequency slurry pump 1 is higher than the critical speed, it can be determined that the outlet is not completely blocked. Under this condition, an instantaneous speed-up strategy can be adopted, which increases the flow rate in the pipeline by rapidly increasing the speed for a short period of time. This utilizes the scouring force generated by the sudden increase in flow velocity to attempt to flush away the blockage and achieve active unblocking. If unblocking is successful, the outlet pressure should reach the corresponding working pressure synchronously when the pump speed returns to the operating speed, indicating that the pipeline has returned to normal operation. Conversely, if the pressure cannot return to the normal range, it indicates that unblocking has failed, and an immediate shutdown operation is required.

[0096] Furthermore, based on the various clogging conditions simulated by the experimental system and their corresponding pressure response data, current intelligent control methods can be further refined. A more precise relationship between clogging and pressure can be established, enabling rapid assessment and accurate control of potential clogging conditions in actual operation.

[0097] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A solid-liquid mixed-transfer pump blockage detection experimental system, characterized in that, include: The system includes a variable frequency slurry pump (1), an inlet conveying pipe (2.1), an outlet conveying pipe (2.2), an inlet pressure transmitter (3.1), an outlet pressure transmitter (3.2), a third shut-off valve (4.3), a fourth shut-off valve (4.4), a frequency converter (5), a computer (6), a cable (7), a signal transmission line (8), a mixing tank (9), and a storage tank (10). The inlet end of the variable frequency slurry pump (1) is fixedly connected to one end of the inlet conveying pipe (2.1), and the outlet end is fixedly connected to one end of the outlet conveying pipe (2.2). The other end of the inlet conveying pipe (2.1) is fixedly connected to the mixing tank (9), which contains experimental particles. The mixture of particles (12) and water, the other end of the outlet conveying pipe (2.2) is connected to two passages, the two passages are respectively suspended above the mixing tank (9) and the storage tank (10), the inlet conveying pipe (2.1) is equipped with an inlet pressure transmitter (3.1) and a third shut-off valve (4.3), the outlet conveying pipe (2.2) is equipped with an outlet pressure transmitter (3.2) and a fourth shut-off valve (4.4), each pressure transmitter is connected to the computer (6) through a signal transmission line (8), the variable frequency slurry pump (1) is connected to the frequency converter (5) through a cable (7), and the frequency converter (5) is connected to the computer (6) through a cable (7).

2. The solid-liquid mixed-transfer pump blockage detection experimental system according to claim 1, characterized in that, The inlet and outlet ends of the variable frequency slurry pump (1) are fixedly connected to the inlet conveying pipe (2.1) and the outlet conveying pipe (2.2) respectively via flanges.

3. The solid-liquid mixed-transfer pump blockage detection experimental system according to claim 1, characterized in that, The mixing tank (9) has a stirring function.

4. The solid-liquid mixed-transfer pump blockage detection experimental system according to claim 1, characterized in that, The storage bin (10) is equipped with a filter barrel (11).

5. The solid-liquid mixed-transfer pump blockage detection experimental system according to claim 1, characterized in that, A first shut-off valve (4.1) and a second shut-off valve (4.2) are fixedly installed on the two passages, respectively.

6. An intelligent control method, employing the solid-liquid mixed-transfer pump blockage detection experimental system as described in any one of claims 1-5, characterized in that, Includes the following steps: Step 1: Monitor the pressure values ​​of the inlet delivery pipeline (2.1) and the outlet delivery pipeline (2.2) in real time using the inlet pressure transmitter (3.1) and the outlet pressure transmitter (3.2), which are the inlet pressure and the outlet pressure, respectively, and upload the monitoring data to the computer (6) for synchronous processing; Step 2.1: When the inlet pressure and outlet pressure decrease relative to their respective normal operating pressure ranges, monitor the change in the rotational speed of the variable frequency slurry pump (1) over time, and make a judgment based on the change in rotational speed; Step 2.1.1 If the rotation speed remains unchanged, it indicates that the inlet is blocked. The computer (6) issues an instruction to control the frequency converter (5) to adjust the rotation speed of the variable frequency slurry pump (1) to 0 within 5 seconds to achieve emergency shutdown. Step 2.1.2: If the speed decreases, it indicates that the blades of the variable frequency slurry pump (1) are blocked. The computer (6) extracts the data of the motor output current and speed and makes a judgment. Step 2.1.2.1 If the speed drops below the critical speed and the output current still exceeds 10% of the rated current, the computer (6) issues a command to control the frequency converter (5) to adjust the speed of the variable frequency slurry pump (1) to 0 to achieve shutdown. Step 2.1.2.2: If the speed drops to above the critical speed and the output current is less than 10% of the rated current, then after running at this speed for 1 minute, readjust the speed of the variable frequency slurry pump (1) to the working speed and monitor the current at this time. Step 2.1.2.2.1 If the current is still greater than 10% of the rated current, the blockage has not been relieved. The computer (6) issues a command to control the frequency converter (5) to adjust the speed of the variable frequency slurry pump (1) to 0 to achieve shutdown. Step 2.1.2.2.2: If the current is less than 10% of the rated current, it indicates that the blockage has been relieved and normal operation can continue. Step 2.2: When the inlet pressure increases and the outlet pressure also increases, it indicates that the outlet of the variable frequency slurry pump (1) is blocked; the computer (6) sends a command to the frequency converter (5) to reduce the speed of the variable frequency slurry pump (1) and continuously monitor the outlet pressure of the outlet conveying pipeline (2.2); Step 2.2.1: If the outlet pressure value still exceeds the normal operating pressure fluctuation range, the speed of the variable frequency slurry pump (1) shall be continuously reduced. Step 2.2.2: If the outlet pressure drops to within the normal operating pressure fluctuation range, extract the speed data of the variable frequency slurry pump (1); Step 2.2.2.1 If the current speed of the variable frequency slurry pump (1) is less than the critical speed, it must be stopped within 5 seconds; Step 2.2.2.2 If the speed of the variable frequency slurry pump (1) is greater than the critical speed, the computer (6) sends an instruction to the frequency converter (5) to adjust the speed to the maximum speed and work for 5 seconds, then reduce it to the working speed and extract the outlet pressure value. Step 2.2.2.2.1: If the outlet pressure value still exceeds the normal operating pressure fluctuation range, shut down the machine immediately within 5 seconds. Step 2.2.2.2.2: If the outlet pressure value is within the normal operating pressure fluctuation range, it indicates that the blockage has been cleared and the system continues to operate.

7. The intelligent control method according to claim 6, characterized in that, In step 2.1.2.2, the operating speed is the speed set at the beginning of the experiment when no blockage occurs.

8. The intelligent control method according to claim 6, characterized in that, In steps 2.2.1, 2.2.2, 2.2.2.2.1 and 2.2.2.2.2, the normal operating pressure is the actual pressure value reached in the outlet conveying pipeline (2.2) when the speed of the variable frequency slurry pump (1) reaches the operating speed.

9. The intelligent control method according to claim 6, characterized in that, In step 2.1.2.1, the critical speed is the speed at which the solid-liquid two-phase flow in the pipeline is just able to be transported along the circulating experimental pipeline; if the speed is lower than the critical speed, the particles will not be transported into the mixing box (9) and the storage box (10).

10. The intelligent control method according to claim 6, characterized in that, In step 2.2.2.2, the maximum speed is the speed that the motor itself can reach when the output current is controlled within a certain range for safe operation, which is greater than the operating speed.

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