Model test device and method for jet collection of deep-sea polymetallic nodules

Abstract

The present invention discloses a deep-sea polymetallic nodule jet collection model test device and method, including a model test frame, a flow control system, a jet collection system, a mobile control system, an intelligent monitoring system, a water tank, and a soil tank; the flow control system includes a water storage tank, a water pump, a solenoid valve, a flow meter, a flow control console, and a water diversion port, the water diversion port provides a diversion flow for each nozzle, and the flow control console controls the jet intensity; the jet collection system includes a water pipe, a nozzle, a guide plate, a ore collection cover, an angle plate, a suction pipeline, a suction pump, and a collection box; the mobile control system includes a mobile support frame, a slide rail, a motor, and an intelligent control device, and the intelligent monitoring system includes a particle imaging speed measurement system, a self-calibration pore water pressure sensor, a laser rangefinder, and a coordinate ruler. The present invention can feedback the jet pressure, velocity, and sediment erosion degree, and can effectively realize the jet collection simulation, clarify the jet collection mechanism, and optimize the design of the collection equipment.

Description

Technical Field

[0001] The invention relates to the field of deep-sea mining model test equipment and technology, and in particular to a deep-sea polymetallic nodule jet collection model test equipment and method. Background Art

[0002] With the growth of population and economy and the deepening of industrialization, the demand for mineral resources is increasing, and the difficulty of mining terrestrial mineral resources is also increasing. In contrast, deep-sea mineral resources are rich and large in scale, which can provide humans with a long-term and stable supply of minerals. Polymetallic nodules are the most abundant seabed mineral resources known so far, and are also the earliest deep-sea minerals to attract global attention and scientific research. However, the mining of deep-sea mineral resources has high technical barriers and development costs, and requires corresponding cooperation in technological progress and sustainability. At present, my country's deep-sea polymetallic nodule collection technology is not mature enough and still faces many challenges.

[0003] Deep-sea sediments have special physical and mechanical properties and complex dynamic evolution mechanisms. Insufficient research on sparse and soft bottom sediments will lead to unreasonable parameter structure matching of the collection head and low collection efficiency. At the same time, the marine ecological environment is extremely fragile. The current deep-sea mining technology and large-scale mining will inevitably have a significant impact on the marine ecological environment. It is urgent to consider the surface area, location, and size of polymetallic nodules, clarify the distribution of the jet flow field, the disturbance of the jet to the sediment and environmental changes, and the start-up and lifting laws of the nodules. Experiments are needed to study the entire collection process.

[0004] The design of a model test device for the jet collection of deep-sea polymetallic nodules needs to simulate the structure and parameters of the deep-sea sparse and soft bottom and the collection head. However, there are currently few double-row jet collection model test devices for deep-sea polymetallic nodules, and there are problems such as the collection head structure and multiple parameters cannot be freely adjusted at the same time, the workload of laying simulated soil in the experiment is large, the velocity and pressure distribution of the flow field cannot accurately collect data, it is difficult to accurately control the progress of collection in a specified area, and there is a lack of quantitative comparison of the effects of suction and jet on the collection rate. Summary of the invention

[0005] In order to solve the above-mentioned problems, the purpose of the present invention is to provide a deep-sea polymetallic nodule jet collection model test device and method. Taking into account the surface area, position and size of the polymetallic nodules, fixed-point and moving collection at any speed can be carried out in a designated area. The collection head structure and multiple jet parameters can be freely replaced and adjusted, and the distribution of the flow field and the movement law of the nodules can be accurately monitored and fed back, and the collection efficiency and bottom sediment disturbance during the collection process can be tested and analyzed.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A deep-sea polymetallic nodule jet collection model test device, characterized in that it includes a model test frame, a flow control system, a jet collection system, a mobile control system, an intelligent monitoring system, a water tank, and a sediment simulation soil tank.

[0008] The model test frame includes a movable support frame, 6 nozzle height adjustment brackets, and a transverse bracket. The PVC water pipe passes through the nozzle height adjustment bracket and is connected to the nozzle. The 6 nozzle height adjustment brackets are connected to the transverse bracket through a slot, and the slot is welded to the transverse fixed frame. A control valve is installed on each height adjustment bracket. Steel plates are welded on the upper part of the fixed frames on both sides, and the collection box is placed on the steel plate. The overall frame is made of aluminum alloy profiles.

[0009] The flow control system includes a water tank, a water pump, a solenoid valve, a flow meter, a flow control console, and a water diversion port. The water diversion port is installed at the junction of the flow control system and the jet collection system, and can provide a diversion flow for each nozzle. The flow control console is connected to a stainless steel pipeline that cooperates with the solenoid valve and the flow meter. The other end of the stainless steel pipeline is connected to the water pump to accurately control the jet intensity of each nozzle outlet, realize the quantitative control cut-off function and the conversion of flow rate and flow, and record the quantitative number, quantitative value and quantitative time.

[0010] The jet collection system includes a water pipe, a nozzle, a guide plate, a mineral collection cover, a suction pipe, a suction pump, and a collection box. The water pipe is made of PVC and supported and adjusted by a stainless steel frame. It passes through the lower part of the guide plate and is connected to three groups of double-row jet nozzles respectively. The guide plate is connected to the mineral collection cover. The suction pipe is located at the center of the mineral collection cover and is set to be compressible. The end of the suction pipe is a collection box, wherein the nozzle structure can be replaced with type A and type B, the jet target distance is 100-400 mm, the adjustment angle is 0-90 degrees, the collection box is installed on the welded steel plate on the upper part of the PVC water pipe support frame, and the suction pump is placed in the collection box to provide suction force for collection.

[0011] The mobile control system includes a mobile support frame, a slide rail, a motor, and an intelligent control device. The mobile support frame surrounds the water tank. Horizontal slide rails are set on the support frames on both sides. Limit blocks are set at the terminals of the slide rails, and the slide rails are connected to the motor. The intelligent control device can control the distance and moving speed of the moving jet. The collection moving speed is 0-3 m / s, which can achieve stopping at any position, and cooperate with the limit block to avoid collision of the mobile collection equipment.

[0012] The intelligent monitoring system includes a particle imaging velocimetry system, a self-calibrating pore water pressure sensor, a laser rangefinder, and a coordinate ruler; the particle imaging velocimetry system includes a high-speed digital camera, a laser, a synchronous control mechanism, and image analysis software, and is located on one side of a water tank for measuring a flow field; the self-calibrating pore water pressure sensor is buried in a position slightly below the middle of the simulated sediment and is connected to a data acquisition instrument; the laser rangefinder is attached to the lower part of a steel plate; and the coordinate ruler is attached to the outside of the water tank.

[0013] The water trough has a size of 2-2.5 m × 0.4-0.6 m × 0.5-0.8 m, can withstand a jet water pressure of 30 MPa, and provide experimental conditions for submerged jets. When performing mobile jet collection, simulated sediments with a thickness of 0.2-0.3 m are laid. The soil trough is used for fixed-point collection to reduce the experimental workload. It has a size of 0.4-0.6 m × 0.2-0.5 m ×0.2-0.5 m, and the thickness of the simulated sediments is flush with the upper part of the soil trough.

[0014] Furthermore, the origin of the coordinate ruler coincides with the bottom of the water tank, and a high-density grid is provided to facilitate accurate marking and recording, and a high-speed digital camera is used to collect data on the starting vertical displacement and horizontal displacement of the nodule.

[0015] Furthermore, the nozzle is located at the lower part of the guide plate and is fixed to a telescopic rod for adjusting the target distance. The telescopic rod is adjusted along the center line direction of the nozzle, and the target distance is controlled by adjusting the telescopic rod. The angle adjustment of the nozzle is completed by a movable angle plate, which is made of 3D printing of resin material. The nozzle is set to be detachable and replaceable with different structures (type A or type B).

[0016] Furthermore, in the flow control system, each nozzle is provided with a control valve to perform jet work individually or simultaneously, the maximum flow rate that each nozzle can reach is 12 m / s, and the nozzle diameter is 11-13 mm; the inner diameter of the water pipe is 10-14 mm, the wall thickness is 2 mm, and the length is 3-8 m, which does not affect the movement of the movable support frame from one end of the water tank to the other.

[0017] Furthermore, the guide plate is a curvature plate with a certain curvature, and the ore collecting cover structure can be replaced into five structures: arc shape (A cover), sloping roof vertical shape (B cover), flat roof vertical shape (C cover), dome vertical shape (D cover), and dome sloping surface shape (E cover).

[0018] Furthermore, the diameter of the suction pipe is set to 100-200 mm, the suction speed can be adjusted to a maximum of 6 m / s, the suction pipe is made of retractable material, and is integrated with the nozzle height adjustment bracket from the bottom. The height of the collection device from the bottom is adjusted to 60-200 mm. There is an inclined pipe at the bottom of the suction pipe, and the upper part is connected to the collection box.

[0019] Furthermore, the high-speed digital camera is placed on one side of the water tank for measuring the flow field. The high-speed digital camera performs automatic tracking to obtain the flow velocity vector of each point in the flow field. The acquisition frequency is 1500 FPS and the spatial resolution is 1.2 mm×1.2 mm. The software part is responsible for processing the image and providing feedback on the velocity distribution and streamlines of the entire jet flow field.

[0020] Furthermore, the self-calibration pore water pressure sensor measures the impact dynamic pressure of the jet on the simulated soil, and the self-calibration pressure sensor is used to avoid errors caused by the submerged environment and time. The laser rangefinder measures the depth of the jet erosion sediment.

[0021] The present application also provides a deep-sea polymetallic nodule jet collection model test method, including the above-mentioned deep-sea polymetallic nodule jet collection model test device, the method comprising the following steps:

[0022] Step (1) Before the experiment is carried out, a simulation design of seabed sediment collection by jet flow of polymetallic nodules is carried out. Specifically, the simulated bottom soil ratio should be determined based on the physical and mechanical properties of deep-sea undisturbed soil and the size ratio of the water / soil trough, and the depth of the bottom sediment laying should be determined based on the experiment;

[0023] Step (2) After the bottom sediment simulation is completed, the entire collection system is pre-tested to ensure the normal operation of the collection system and to prevent leakage in the pipeline and inability of the experimental equipment to operate;

[0024] Step (3) After the acquisition system is debugged, the simulated bottom soil is laid in the water tank until the target depth is reached, and the nodules are buried in the soil in the specified form. Then, water is added to the inside of the water tank to cover the soil layer to achieve the condition of submerging the jet, and the soil is left to solidify. The initial depth of the bottom surface is measured using a laser rangefinder;

[0025] Step (4) according to the jet height, target distance and angle designed for each working condition, adjust the model frame, the telescopic length of the nozzle bracket and the angle plate, select a suitable nozzle structure, control the jet time and speed on the flow control console, and perform jet collection after the jet system is stable;

[0026] Step (5) replacing the ore collecting cover according to the test working conditions to determine the flow field structure of different ore collecting covers, and determining whether to add suction effect according to the working conditions;

[0027] Step (6) the collection device moves forward at the required forward speed and stops at the end, the ore collection is sucked at the required speed, waiting for the suspended sediment particles to settle, and the final bottom depth is measured again;

[0028] Step (7) during the collection period, record the real-time output of the pressure sensor and the flow field changes, observe and record the start-up and migration of the nodules, and evaluate the collection efficiency based on the number of nodules in the collection box at the end of the collection;

[0029] Step (8) repeats multiple experiments with different parameter structures. After the experiment is completed, the experimental system is closed and the bottom is photographed and recorded so that the experimental results of different working conditions can be compared. After the experiment is completed, the device is cleaned and anti-corrosion measures are taken. The data is sorted and quantitative expression is formed.

[0030] Beneficial effects of the present invention:

[0031] The present invention provides a deep-sea polymetallic nodule jet collection model test device and method. The test device simulates the deep-sea environment in the form of submerged jets, can carry out deep-sea double-row jet fixed-point and mobile collection tests at any speed, and simulate the forward collection of a mining vehicle; can realize the comparative quantitative study of the single targetedness and synergistic effects of the jet action and the suction action on the collection efficiency, and realize the study of the whole process of flushing-stripping-lifting-mining;

[0032] The present invention provides a deep-sea polymetallic nodule jet collection model test device and method, which can realize the collection test of different simulated bottoms, and the jet angle, jet velocity, jet height, jet target distance, nozzle structure, and collection forward speed of the double-row nozzles can be freely adjusted to perform simulation tests, so as to realize the test of the influence of a single / multiple parameter combination of the jet on the collection efficiency, simulate different working conditions for actual conditions, optimize the design of combination parameters, guide actual engineering applications, and solve the problem of a single control parameter of the jet collection device;

[0033] The present invention provides a deep-sea polymetallic nodule jet collection model test device and method, which can realize the influence of the collection device structure on the collection rate, can carry out experimental tests on guide plates with different curvatures and ore collection covers with different structures, the suction speed is controllable and the suction pipeline is retractable, which enhances the practicality of the collection device and effectively realizes the dynamic, convenient and efficient test simulation of the polymetallic nodule jet collection under the overall structure;

[0034] The present invention provides a deep-sea polymetallic nodule jet collection model test device and method, and provides an intelligent monitoring system that can truly test the velocity, pressure distribution, start-up and deviation displacement of nodules, and soil erosion of the entire collection flow field, and collect, store and process data in real time during the test, solving the problem that the flow field changes and nodule movement trajectories during the test cannot be fed back in digital form.

[0035] The present invention provides a deep-sea polymetallic nodule jet collection model test device and method. During fixed-point collection, lightweight and small-sized soil troughs are used to lay different simulated bottom soils instead of water troughs, which solves the problem of heavy engineering workload of frequently replacing simulated soils for a large number of different working conditions, saves time and improves test efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0037] Figure 2 It is a top view of the main structure of the present invention;

[0038] Figure 3 It is a schematic diagram of the tuberculosis collection test of the present invention;

[0039] Figure 4 Schematic diagram of different structures of the ore collecting cover and the nozzle of the present invention;

[0040] Figure 5 It is a working schematic diagram of the speed measurement system of the present invention;

[0041] Figure 6 It is a schematic diagram of the detailed structure of the acquisition device of the present invention;

[0042] In the figure, 1, water tank, 2, soil trough, 3, model experiment frame, 4, water storage tank, 5, water pump, 6, solenoid valve, 7, flow meter, 8, flow control console, 9, water diversion port, 10, water pipe, 11, stainless steel pipeline, 12, water pipe support and adjustment frame, 13, control valve, 14, guide plate, 15, ore collection cover, 16, nozzle, 17, angle plate, 18, suction pipe, 19, suction pump, 20, collection box, 21, steel plate, 22, mobile support frame, 23, horizontal bracket, 24, slide rail, 25, motor, 26, intelligent control equipment, 27, limit block, 28, telescopic rod, 29, laser rangefinder, 30, high-speed digital camera, 31, laser, 32, synchronous control mechanism, 33, image analysis software, 34, self-calibration pore water pressure sensor, 35, polymetallic nodules. DETAILED DESCRIPTION

[0043] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0044] The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no substantial technical significance. Any modification of the structure, change of the proportion relationship or adjustment of the size, without affecting the effects and purposes that can be achieved by the present invention, should still fall within the scope of the technical content disclosed by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. The change or adjustment of their relative relationship should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

[0045] like Figure 1-2 The figure shows a deep-sea polymetallic nodule jet collection model test device, which is characterized by comprising a model test frame, a flow control system, a jet collection system, a mobile control system, an intelligent monitoring system, a water tank 1, and a sediment simulation soil tank 2.

[0046] like Figure 1-2 As shown, the model test frame 3 includes a movable support frame 22, 6 nozzle height adjustment brackets 12, and a transverse bracket 23. The PVC water pipe passes through the nozzle height adjustment bracket 12 and is connected to the nozzle 16. The 6 nozzle height adjustment brackets 12 are connected to the transverse bracket 23 through a slot, and the slot is welded to the transverse fixed frame 23. A control valve 13 is installed on each height adjustment bracket 12. Steel plates 21 are welded on the upper part of the fixed frames on both sides. The collection box 20 is placed on the steel plate 21, and the overall frame is made of aluminum alloy profiles.

[0047] like Figure 1-2 As shown, the flow control system includes a water tank 4, a water pump 5, a solenoid valve 6, a flow meter 7, a flow control console 8, and a water diversion port 9. The water diversion port 9 is installed at the junction of the flow control system and the jet collection system, and can provide a diversion flow for each nozzle 16. The flow control console 8 is connected to a stainless steel pipeline 11 that cooperates with the solenoid valve 6 and the flow meter 7. The other end of the stainless steel pipeline 11 is connected to the water pump 5, and the jet intensity at the outlet of each nozzle 16 is accurately controlled to realize the quantitative control cut-off function and the conversion of flow velocity and flow rate, and record the quantitative number, quantitative value and quantitative time.

[0048] like Figure 3-4As shown, the jet collection system includes a water pipe 10, a nozzle 16, a guide plate 14, a mineral collection cover 15, a suction pipe 18, a suction pump 19, and a collection box 20. The water pipe 10 is made of PVC and supported and adjusted by a stainless steel frame 12. It passes through the lower part of the guide plate 14 and is connected to three groups of double-row jet nozzles 16 respectively. The guide plate 14 is connected to the mineral collection cover 15. The suction pipe 18 is located at the center of the mineral collection cover 15 and is set to be compressible. The end of the suction pipe 18 is a collection box 20, wherein the nozzle 16 structure can be replaced with type A and type B, the jet target distance is 100-400 mm, the adjustment angle is 0-90 degrees, and the collection box 20 is installed on the welded steel plate 21 on the upper part of the PVC water pipe support frame 12. The suction pump 19 is placed in the collection box 20 to provide suction force for collection.

[0049] like Figure 1-2 As shown, the mobile control system includes a mobile support frame 22, a slide rail 24, a motor 25, and an intelligent control device 26. The mobile support frame 22 surrounds the water tank 1. Horizontal slide rails 24 are provided on the support frames on both sides. A limit stopper 27 is provided at the terminal of the slide rail 24. The slide rail 2426 is connected to the motor 25. The intelligent control device can control the distance and moving speed of the moving jet. The collection moving speed is 0-3 m / s, which can stop walking at any position, and cooperate with the limit stopper 27 to avoid collision of the mobile collection equipment.

[0050] like Figure 1-2 As shown, the intelligent monitoring system includes a particle imaging velocimetry system, a self-calibrating pore water pressure sensor 34, a laser rangefinder 29, and a coordinate ruler; the particle imaging velocimetry system includes a high-speed digital camera 30, a laser 31, a synchronous control mechanism 32, and an image analysis software 33, and is located on one side of the water tank 1 for measuring the flow field; the self-calibrating pore water pressure sensor 34 is buried in a position slightly below the middle of the simulated sediment and is connected to a data acquisition instrument; the laser rangefinder 29 is attached to the lower part of the steel plate 21; and the coordinate ruler is attached to the outside of the water tank 1.

[0051] like Figure 1-3 As shown, the water tank 1 has a size of 2-2.5 m×0.4-0.6 m×0.5-0.8 m, can withstand a jet water pressure of 10-30 MPa, and provide experimental conditions for submerged jets. When performing mobile jet collection, simulated sediments are laid with a thickness of 0.2-0.3 m; the soil trough 2 is used for fixed-point collection to reduce the experimental workload, with a size of 0.4-0.6 m×0.2-0.5 m×0.2-0.5 m, and the thickness of the simulated sediments is flush with the upper part of the soil trough.

[0052] Furthermore, the origin of the coordinate ruler coincides with the bottom of the water tank 1 , and a high-density grid is provided to facilitate accurate marking and recording, and the high-speed digital camera 30 is used to collect data on the starting vertical displacement and horizontal displacement of the nodule 35 .

[0053] like Figure 6 As shown, the nozzle 16 is located at the lower part of the guide plate 14 and is fixed to the telescopic rod 28 for adjusting the target distance. The telescopic rod 28 is adjusted along the center line direction of the nozzle. The angle adjustment of the nozzle 16 is completed by the movable connection angle plate 17, and the angle plate 17 is made of resin material 3D printing; the nozzle 16 is set to be detachable and replaceable with different structures (type A or type B).

[0054] like Figure 3 As shown, each nozzle 16 is provided with a control valve 13 to perform jetting work individually or simultaneously, and the maximum flow rate that each nozzle 16 can reach is 12m / s, and the nozzle diameter is 11-13mm; the inner diameter of the water pipe is 10-14mm, the wall thickness is 2mm, and the length is 3-8m, which does not affect the movement of the movable support frame 22 from one end of the water tank 1 to the other end.

[0055] like Figure 4 As shown, the guide plate 14 is a curvature plate with a certain arc, and the structure of the ore collecting cover 15 can be replaced into five structures: arc shape (A cover), inclined roof vertical shape (B cover), flat roof vertical shape (C cover), dome vertical shape (D cover), dome inclined surface shape (E cover).

[0056] like Figure 6 As shown, the diameter of the suction pipe 18 is set to 100-200 mm, the suction speed can be adjusted to a maximum of 6 m / s, the suction pipe 18 is made of retractable material, and is integrated with the nozzle height adjustment bracket 12 from the bottom, and the height of the collection device from the bottom is adjusted to 60-200 mm. The lower part of the suction pipe 18 has a section of inclined pipe, and the upper part is connected to the collection box 20.

[0057] like Figure 5 As shown, the high-speed digital camera 30 is placed on one side of the water tank for measuring the flow field. The high-speed digital camera 30 performs automatic tracking to obtain the flow velocity vector of each point in the flow field. The acquisition frequency is 1500 FPS and the spatial resolution is 1.2 mm×1.2 mm. The software part is responsible for processing the image and providing feedback on the velocity distribution and streamlines of the entire jet flow field.

[0058] like Figure 3 As shown, the self-calibration pore water pressure sensor 34 measures the impact dynamic pressure of the jet on the simulated soil. The self-calibration pressure sensor 34 is used to avoid errors caused by the flooding environment and time. The laser rangefinder 29 measures the depth of the jet erosion sediment.

[0059] The present application also provides a deep-sea polymetallic nodule jet collection model test method, including the above-mentioned deep-sea polymetallic nodule jet collection model test device, the method comprising the following steps:

[0060] Step (1) Before the experiment is carried out, a simulation design of seabed sediment collection by jet flow of polymetallic nodules is carried out. Specifically, the simulated bottom soil ratio should be determined based on the physical and mechanical properties of deep-sea undisturbed soil and the size ratio of water tank 1 and soil tank 2, and the depth of laying the bottom soil should be determined according to the experiment;

[0061] Step (2) After the bottom sediment simulation is completed, the entire collection system is pre-tested to ensure the normal operation of the collection system and to prevent leakage in the pipeline and inability of the experimental equipment to operate;

[0062] Step (3) After the acquisition system is debugged, the simulated bottom soil is laid in the water tank 1 until the target depth is reached, and the nodules 35 are buried in the soil in a specified form. Then, water is added to the inside of the water tank 1 to cover the soil layer to achieve the condition of submerging the jet, and the soil is left to solidify. The initial depth of the bottom surface is measured using a laser rangefinder 29;

[0063] Step (4) according to the jet height, target distance and angle designed for each working condition, the model frame 12, the telescopic length of the nozzle bracket 28 and the angle plate 17 are adjusted, a suitable nozzle 16 structure is selected, the jet time and speed are controlled by the flow control console 8, and the jet is collected after the jet system is stable;

[0064] Step (5) replacing the ore collecting cover 15 according to the test working conditions to determine the flow field structure of different ore collecting covers 15, and determining whether to add a suction effect according to the working conditions;

[0065] Step (6) the collection device moves forward at the required forward speed and stops at the end, the ore collection is sucked at the required speed, waiting for the suspended sediment particles to settle, and the final bottom depth is measured again;

[0066] Step (7) during the collection period, record the real-time output of the pressure sensor 34 and the flow field changes, observe and record the start-up and migration of the nodules 35, and after the collection is completed, evaluate the collection efficiency according to the number of nodules 35 in the collection box 20;

[0067] Step (8) repeats multiple experiments with different parameter structures. After the experiment is completed, the experimental system is closed and the bottom is photographed and recorded so that the experimental results of different working conditions can be compared. After the experiment is completed, the device is cleaned and anti-corrosion measures are taken. The data is sorted and quantitative expression is formed.

Claims

1. A deep-sea polymetallic nodule jet collection model test device, characterized in that: It includes model test frame, flow control system, jet collection system, mobile control system, intelligent monitoring system, water tank, and sediment simulation soil tank; The model test frame includes a mobile support frame, 6 nozzle height adjustment brackets, and a transverse bracket. The PVC water pipe passes through the nozzle height adjustment bracket and is connected to the nozzle. The 6 nozzle height adjustment brackets are connected to the transverse bracket through a slot, and the slot is welded to the transverse fixed frame. A control valve is installed on each height adjustment bracket. Steel plates are welded on the upper part of the fixed frames on both sides, and the collection box is placed on the steel plate. The overall frame is made of aluminum alloy profiles. The flow control system includes a water tank, a water pump, a solenoid valve, a flow meter, a flow control console, and a water outlet. The water outlet is installed at the junction of the flow control system and the jet collection system, and can provide a flow rate for each nozzle. The flow control console is connected to a stainless steel pipeline that cooperates with the solenoid valve and the flow meter. The other end of the stainless steel pipeline is connected to the water pump to accurately control the jet intensity of each nozzle outlet, realize the quantitative control cut-off function and the conversion of flow rate and flow, and record the quantitative times, quantitative values ​​and quantitative time; The jet collection system includes a water pipe, a nozzle, a guide plate, a mineral collection cover, a suction pipe, a suction pump, and a collection box. The water pipe is made of PVC, supported and adjusted by a stainless steel frame, and passes through the lower part of the guide plate to be connected to three groups of double-row jet nozzles respectively. The guide plate is connected to the mineral collection cover. The suction pipe is located at the center of the mineral collection cover and is set to be compressible. The end of the suction pipe is a collection box, wherein the nozzle structure can be replaced with type A and type B, the jet target distance is 100mm-400mm, the adjustment angle is 0-90 degrees, the collection box is installed on the welded steel plate on the upper part of the PVC water pipe support frame, and the suction pump is placed in the collection box to provide suction force for collection; The mobile control system includes a mobile support frame, a slide rail, a motor, and an intelligent control device. The mobile support frame surrounds the water tank. The support frames on both sides are provided with horizontal slide rails. The terminals of the slide rails are provided with limit blocks, and the slide rails are connected to the motors. The intelligent control device can control the distance and moving speed of the moving jet. The collection moving speed is 0-3 m / s, which can realize stopping at any position, and cooperate with the limit block to avoid collision of the mobile collection equipment. The intelligent monitoring system includes a particle imaging velocity measurement system, a self-calibrating pore water pressure sensor, a laser rangefinder, and a coordinate ruler; the particle imaging velocity measurement system includes a high-speed digital camera, a laser, a synchronous control mechanism, and an image analysis software, and is located on one side of a water tank for measuring the flow field; the self-calibrating pore water pressure sensor is buried in a position slightly below the middle of the simulated sediment and connected to a data acquisition instrument; the laser rangefinder is attached to the lower part of the steel plate; and the coordinate ruler is attached to the outside of the water tank; The water tank has a size of 2-2.5 m × 0.4-0.6 m × 0.5-0.8 m, can withstand a jet water pressure of 30 MPa, provides experimental conditions for submerged jets, and lays simulated sediments with a thickness of 0.2-0.3 m when performing mobile jet collection; The sediment simulation soil trough is used for fixed-point collection to reduce the test workload, and has a size of 0.4-0.6 m × 0.2-0.5 m × 0.2-0.5 m. The thickness of the simulated sediment is flush with the upper part of the soil trough.

2. A deep-sea polymetallic nodule jet collection model test device according to claim 1, characterized in that: The origin of the coordinate ruler coincides with the bottom of the water tank, and a high-density grid is provided to facilitate accurate marking and recording, and a high-speed digital camera is used to collect data on the starting vertical displacement and horizontal displacement of the nodule.

3. A deep-sea polymetallic nodule jet collection model test device according to claim 1, characterized in that: The nozzle is located at the lower part of the guide plate and is fixed to a telescopic rod for adjusting the target distance. The telescopic rod is adjusted along the center line direction of the nozzle, and the target distance is controlled by adjusting the telescopic rod. The angle adjustment of the nozzle is completed by a movable angle plate, which is made of 3D printing of resin material. The nozzle is set to a detachable structure and can be replaced with type A or type B structures according to test needs.

4. A deep-sea polymetallic nodule jet collection model test device according to claim 1, characterized in that: The flow control system has a control valve for each nozzle to perform jetting work individually or simultaneously, and the maximum flow rate that each nozzle can reach is 12 m / s, and the nozzle diameter is 11-13 mm; the inner diameter of the water pipe is 10-14 mm, the wall thickness is 2 mm, and the length is 3-8 m, which does not affect the movement of the movable support frame from one end of the water tank to the other.

5. A deep-sea polymetallic nodule jet collection model test device according to claim 1, characterized in that: The guide plate is a curvature plate with a certain arc, and the ore collecting cover structure can be replaced with five structures, namely, arc-shaped A cover, sloping roof vertical surface shaped B cover, flat roof vertical surface shaped C cover, dome vertical surface shaped D cover, and dome sloping surface shaped E cover.

6. A deep-sea polymetallic nodule jet collection model test device according to claim 1, characterized in that: The diameter of the suction pipe is set to 100-200 mm, and the maximum suction speed can be adjusted to 6 m / s. The suction pipe is made of retractable material and is integrated with the nozzle height adjustment bracket. The height of the collection device from the bottom is adjusted to 60-200 mm. There is an inclined pipe at the bottom of the suction pipe, and the upper part is connected to the collection box.

7. A deep-sea polymetallic nodule jet collection model test device according to claim 1, characterized in that: The high-speed digital camera is placed on one side of the water tank for measuring the flow field. The high-speed digital camera takes pictures and automatically tracks to obtain the flow velocity vector of each point in the flow field. The acquisition frequency is 1500 FPS and the spatial resolution is 1.2 mm × 1.2 mm. The software part is responsible for processing the image and providing feedback on the velocity distribution and streamlines of the entire jet flow field.

8. A deep-sea polymetallic nodule jet collection model test device according to claim 1, characterized in that: The self-calibration pore water pressure sensor measures the impact dynamic pressure of the jet on the simulated soil. The self-calibration pressure sensor is used to avoid errors caused by the submerged environment and time. The laser rangefinder measures the depth of the jet erosion sediment.

9. A model test method for collecting deep-sea polymetallic nodules is provided by using the deep-sea polymetallic nodule jet collection model test device according to any one of claims 1 to 8, characterized in that: The steps include: Step (1) Before the test, a simulation design of seabed sediment collection by jet flow of polymetallic nodules is carried out. Specifically, based on the physical and mechanical properties of deep-sea undisturbed soil and the size ratio of water / soil troughs, the simulated bottom soil ratio is determined, and the depth of laying the bottom soil is determined according to experiments; Step (2) After the bottom sediment simulation is completed, the entire collection system is pre-tested to ensure the normal operation of the collection system and to prevent leakage in the pipeline and inability of the experimental equipment to operate; Step (3) After the acquisition system is debugged, the simulated bottom soil is laid in the water tank until the target depth is reached, and the nodules are buried in the soil in the specified form. Then, water is added to the inside of the water tank to cover the soil layer to achieve the condition of submerging the jet, and the soil is left to solidify. The initial depth of the bottom surface is measured using a laser rangefinder; Step (4) according to the jet height, target distance and angle designed for each working condition, adjust the model frame, the telescopic length of the nozzle bracket and the angle plate, select a suitable nozzle structure, control the jet time and speed on the flow control console, and perform jet collection after the jet system is stable; Step (5) replacing the ore collecting cover according to the test working conditions to determine the flow field structure of different ore collecting covers, and determining whether to add suction effect according to the working conditions; Step (6) the collection device moves forward at the required forward speed and stops at the end, the ore collection is sucked at the required speed, waiting for the suspended sediment particles to settle, and the final bottom depth is measured again; Step (7) during the collection period, record the real-time output of the pressure sensor and the flow field changes, observe and record the start-up and migration of the nodules, and evaluate the collection efficiency based on the number of nodules in the collection box at the end of the collection; Step (8) repeats multiple experiments with different parameter structures. After the experiment is completed, the experimental system is closed and the bottom is photographed and recorded so that the experimental results of different working conditions can be compared. After the experiment is completed, the device is cleaned and anti-corrosion measures are taken. The data is sorted and quantitative expression is formed.

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