Hydro-pneumatic combined pipe lifting system and method for deep-sea mining micro-nano bubble

Abstract

The application discloses a deep-sea mining micro-nano bubble hydraulic-pneumatic combined pipeline lifting system and method, wherein the lifting system comprises a lifting pipe, and at least one gas-liquid injection assembly is arranged on the lifting pipe in a flowing direction; the gas-liquid injection assembly comprises an annular pressure equalizing chamber, an injection inlet and a plurality of nozzle assemblies; the inlet of the nozzle assembly is communicated with the annular pressure equalizing chamber, and the outlet of the nozzle assembly is configured to make the injection jet flow have a radial component, a tangential component and an axial component in the same direction as the main flow of the ore slurry in the lifting pipe; each nozzle assembly comprises a throttling structure and a one-way check structure; the injection inlet is communicated with a micro-nano bubble-containing carrier liquid source; and a control system adjusts the gas flow, the carrier liquid flow or the injection pressure difference according to the absolute pressure difference between the annular pressure equalizing chamber and the lifting pipe, so that the pressure difference covers the check opening pressure difference, the nozzle design flow pressure drop and the safety pressure difference allowance. The application can reduce the risk of ore slurry backflow, realizes segmented closed-loop control and is convenient to maintain.

Description

Technical Field

[0001] This invention relates to the field of deep-sea mineral resource mining and multiphase flow pipeline transportation technology, specifically to a deep-sea mining micro-nano bubble hydraulic-pneumatic combined pipeline lifting system and method. Background Technology

[0002] Deep-sea mining systems typically include seabed ore collection equipment, vertical lifting pipelines, and surface support platforms. The vertical lifting process requires the continuous transport of solid particles to the surface under high external pressure, long distances, abrasive slurry, and sea disturbances. Its energy consumption, blockage risk, and fault recovery capabilities directly affect the availability of the mining system.

[0003] Current hydraulic lifting primarily relies on ore pumps to achieve the required flow velocity for particle suspension in the slurry. However, as solid concentration, particle size, and particle density increase, the increased pump power required to maintain a safe flow velocity exacerbates pressure loss along the pipe, particle collisions, and pipe wall wear. Pneumatic lifting or a combined hydraulic-pneumatic approach can alter the mixture's density and flow structure by introducing a gas phase. However, issues such as gas supply pressure, gas dissolution and expansion, bubble coalescence, and eccentric gas phase distribution in deep-sea environments cause the lifting effect to vary significantly with depth.

[0004] Common single-point or multi-point gas injection structures are prone to forming localized gas columns, eccentric gas holdup, and intermittent large gas masses. If compressed gas is directly injected into high-pressure slurry, slurry backflow can occur if the supply pressure is slightly lower than the pressure inside the pipe, leading to gas path blockage and damage to the bubble generator. Using only an annular cavity without limiting the resistance of each branch cannot guarantee consistent flow rates at each nozzle, as the circumferential pressure difference within the annular cavity, nozzle wear, and particle intrusion will continuously alter the branch flow rates.

[0005] On the other hand, if a traditional Venturi bubble generator is directly connected in series with the main slurry pipeline, the throat is susceptible to impact from large-diameter ore particles, resulting in additional pressure loss. If the bubble generator's pressure is not matched with the main pipeline pressure, the generated bubbles may dissolve, coalesce, or undergo sudden expansion before entering the main pipeline. During deepwater hoisting, the gas phase state changes with absolute pressure and temperature, and an empirical arrangement with a fixed depth and fixed injection volume is difficult to cover different working conditions.

[0006] Therefore, a device is needed that forms a closed-loop technology chain of high-pressure bubble generation, annular pressure equalization and distribution, branch anti-backflow, jet direction control, and segmented state feedback, so that each injection segment can establish a controllable pressure difference based on the local absolute pressure in the pipe, and achieve stable and maintainable gas-containing carrier liquid injection without allowing large particles to enter the bubble generation unit. Summary of the Invention

[0007] The purpose of this invention is to provide a micro-nano bubble hydraulic-pneumatic combined pipeline lifting system and method for deep-sea mining, which at least partially solves one of the technical problems in related technologies.

[0008] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A deep-sea mining micro-nano bubble hydraulic-pneumatic combined pipeline lifting system includes a ore lifting pump and a lifting pipe connected to the ore lifting pump. At least one gas-liquid injection component is arranged on the lifting pipe downstream of the ore lifting pump along the flow direction. The gas-liquid injection assembly includes an annular pressure equalization chamber arranged around the riser tube, an injection inlet communicating with the annular pressure equalization chamber, and a plurality of nozzle assemblies arranged along the circumference of the annular pressure equalization chamber. The inlet of the nozzle assembly is connected to the annular equalizing chamber, and the outlet of the nozzle assembly is configured such that the injected jet has a radial component toward the tube center, a tangential component, and an axial component in the same direction as the mainstream slurry in the riser. Each nozzle assembly includes a throttling structure and a one-way check structure. The one-way check structure is used to allow the carrier liquid containing micro-nano bubbles to be injected unidirectionally from the annular equalizing chamber into the riser, and to prevent the slurry in the riser from entering the nozzle assembly and the annular equalizing chamber in the reverse direction. The injection inlet is connected to a liquid source containing micro-nano bubbles; It also includes a control system, which adjusts the liquid source containing micro-nano bubbles according to the absolute pressure difference between the annular equalizing chamber and the riser pipe, so that the absolute pressure difference between the annular equalizing chamber and the riser pipe is not less than the sum of the opening pressure difference of the one-way check structure, the design flow pressure drop of the nozzle assembly, and the safety pressure difference margin.

[0009] Furthermore, the micro-nano bubble-containing liquid source includes a micro-nano bubble generating unit arranged in a bypass liquid-carrying circuit, wherein the bypass liquid-carrying circuit transports a clean liquid that does not contain large-particle-size ore or a liquid that has been separated from the solid-liquid mixture.

[0010] Furthermore, the micro-nano bubble generating unit includes a gas-liquid premixing or dissolved gas chamber, a constriction throat, a swirling shear section and a diffuser section arranged sequentially and connected along the flow direction. The gas-liquid premixing or dissolved gas chamber is provided with a liquid inlet and a gas inlet. The outlet of the diffuser section is provided with a back pressure regulating element for maintaining the outlet pressure of the generating unit. It also includes a pressure detection element for detecting the inlet and outlet pressures of the micro / nano bubble generating unit.

[0011] Furthermore, the design flow pressure drop of the nozzle assembly is not less than three times the maximum circumferential pressure deviation of the annular equalizing chamber.

[0012] Furthermore, the jet direction of the nozzle assembly forms a tangential deflection angle β of 10-35 degrees relative to the inward radial direction within the cross-section of the riser tube, and an axial angle γ of 20-70 degrees relative to the central axis of the riser tube.

[0013] Furthermore, the gas-liquid injection assembly is a detachable short section structure, including a riser tube short section and an assembly housing arranged around the outside of the riser tube short section. The annular pressure equalization cavity is formed between the inner wall of the assembly housing and the outer wall of the riser tube short section, and a flow guiding or damping structure is provided in the annular pressure equalization cavity. The component housing is provided with a cavity pressure measuring point for measuring the pressure of the annular equalizing cavity, and the lift tube short section is provided with a tube pressure measuring point for measuring the pressure inside the tube. The cavity pressure measuring point and the tube pressure measuring point are located at the same or adjacent axial positions.

[0014] Furthermore, the control system includes a monitoring unit, a control unit, and an execution unit; Downstream of each gas-liquid injection assembly is a monitoring unit for characterizing at least two of the following: pressure, delivery flow rate, solid concentration, and gas phase state. The execution unit includes a segmented isolation valve corresponding to each gas-liquid injection component, a liquid booster pump installed in the liquid supply pipeline upstream of the liquid inlet, and a gas regulating valve installed in the gas supply pipeline upstream of the gas inlet. The control unit adjusts the gas flow rate, liquid flow rate, or injection pressure difference of each gas-liquid injection component based on the absolute pressure difference between the annular equalizing chamber and the riser tube, as well as the output of the monitoring unit.

[0015] Furthermore, the control unit also includes a safety interlock module. When the rate of increase of the main pressure of the riser pipe, the duration of insufficient differential pressure, or the decrease of the liquid flow rate exceeds the calibrated threshold, the safety interlock module closes the gas regulating valve and the segment isolation valve, and maintains short-term flushing of the liquid pump.

[0016] Furthermore, the control system is used to achieve segmented pressure matching and closed-loop control, specifically: The riser is defined as multiple injection sections according to the gas-liquid injection assembly. The control system calculates the difference between the absolute pressure in the annular equalization chamber of each injection section and the absolute pressure in the riser, and combines this with the downstream monitoring unit to estimate the gas phase state, pressure fluctuations, and deposition risks. If the downstream gas phase state is lower than the target and the pressure fluctuation does not exceed the limit, the gas or liquid flow rate of the corresponding injection section is gradually increased. If the pressure fluctuation, gas holdup, or near-wall solid concentration exceeds the limit, the injection rate is reduced or the corresponding injection section is closed.

[0017] This invention also discloses a method for lifting a deep-sea mining micro-nano bubble hydraulic-pneumatic combined pipeline, comprising the following steps: A basic hydraulic transport system for solid-liquid slurry is established within the riser pipe using a ore pump; the absolute pressure within the pipe at the location of the gas-liquid injection component to be injected is obtained; a carrier liquid containing micro-nano bubbles with a pressure higher than the absolute pressure within the riser pipe is prepared in the bypass carrier liquid circuit; after the difference between the absolute pressure within the annular equalizing chamber and the absolute pressure within the riser pipe reaches the sum of the opening pressure difference of the one-way check structure, the design flow pressure drop of the nozzle, and the safety pressure difference margin, the corresponding segmented isolation valve is opened to inject the carrier liquid containing micro-nano bubbles into the riser pipe through the annular equalizing chamber and each nozzle component; and the gas flow rate, carrier liquid flow rate, or injection pressure difference is adjusted according to at least two of the following: downstream pressure, transport flow rate, solid phase concentration, and gas phase state.

[0018] The beneficial effects of this invention are: (1) By establishing a controllable positive pressure difference based on the absolute pressure inside the injection section and setting a one-way check structure in each nozzle branch, the risk of slurry backflow, blockage of gas path and damage to generator when the pressure supply is insufficient can be reduced.

[0019] (2) By combining the annular pressure equalization chamber with the nozzle branch resistance-dominant design, i.e. the design flow pressure drop of the nozzle branch is not less than 3 times the maximum circumferential pressure deviation of the annular pressure equalization chamber, under the injection pressure difference condition that satisfies the check opening pressure difference, the nozzle design flow pressure drop and the safety pressure difference margin, the influence of the circumferential pressure difference of the pressure equalization chamber on the flow rate of each nozzle is limited, and it is easier to obtain calculable and calibrable flow uniformity than a simple annular groove.

[0020] (3) By generating micro-nano bubbles through bypass liquid, large-diameter ore particles are prevented from passing through the Venturi throat and cyclone shearing components, reducing wear and blockage, and avoiding unnecessary throttling pressure loss on the main slurry pipe.

[0021] (4) By using a three-component directional jet to take into account cross-sectional penetration, tangential mixing and downstream flow, the risk of gas phase eccentricity and local gas column caused by single-point gas injection is reduced.

[0022] (5) By matching absolute pressure in segments and using closed-loop control to adapt to pressure changes along the process, segmented regulation is achieved without relying on fixed injection depth or gas-liquid ratio that has not been uniformly converted.

[0023] (6) The gas-liquid injection assembly adopts a detachable short section structure, which improves the accessibility of offshore maintenance and can restore the branch line rated resistance without replacing the entire riser pipe.

[0024] (7) This invention is particularly suitable for long-distance vertical transport of polymetallic nodules, cobalt-rich crust crushed material, polymetallic sulfide mineral particles and other high-density solid particles. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the overall system of the present invention; Figure 2 A longitudinal sectional view of the gas-liquid injection assembly; Figure 3 This is a schematic diagram showing the arrangement of the nozzle assembly within a cross-section; Figure 4 This is a schematic diagram of the arrangement of the nozzle assembly within the longitudinal section; Figure 5 This is a schematic diagram of a micro / nano bubble generating unit; Figure 6 This is a schematic diagram of the nozzle assembly; Figure 7 A schematic diagram showing the gas-liquid injection components and pressure matching relationship installed in sections along the riser pipe; Figure 8 This is a closed-loop block diagram of monitoring-control-execution-interlocking in this invention.

[0026] To better illustrate this embodiment, some components in the accompanying drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product; it is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings. Detailed Implementation

[0027] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0028] Example 1:

[0029] like Figures 1 to 5 As shown, this embodiment provides a deep-sea mining micro-nano bubble hydraulic-pneumatic combined pipeline lifting system, including a seabed ore collection device 1, a ore lifting pump 2, a lifting pipe 3, a gas-liquid injection component, a micro-nano bubble generating unit 5, a gas source 6, a surface operation platform 7, a gas-liquid-solid separation device 8, and a control system 9.

[0030] The seabed ore collection device 1 collects and crushes the ore, forming a solid-liquid slurry with seawater. The ore lifting pump 2 provides the basic hydraulic lifting head, and the slurry is transported to the surface working platform 7 via the lifting pipe 3. The surface working platform 7 is equipped with a gas-liquid-solid separation device 8 and a control system 9.

[0031] For long-distance lifting, this embodiment has three gas-liquid injection components, namely the first gas-liquid injection component 4a, the second gas-liquid injection component 4b, and the third gas-liquid injection component 4c, which are arranged along the flow direction of the slurry in the lift pipe 3. The actual position of each component is determined by the absolute pressure distribution in the pipe, the gas dissolution-precipitation model, the target gas holdup, pressure fluctuations, and the risk of solid deposition, rather than by using a fixed water depth as a necessary limitation.

[0032] In other embodiments, the number of gas-liquid injection components may be one, two, three or more.

[0033] The riser pipe 3 is defined as multiple injection sections according to the gas-liquid injection component. The multiple injection sections can be independently adjusted according to the pressure along the pipe and the gas phase state.

[0034] Each gas-liquid injection component is equipped with an independent segmented isolation valve 53. The segmented isolation valve 53 is located between the outlet of the micro-nano bubble generating unit 5 and the injection inlet 22 of the corresponding gas-liquid injection component, and is used to cut off the micro-nano bubble-containing carrier liquid of the corresponding injection segment during start-up, shutdown, flushing or abnormal operating conditions.

[0035] The three gas-liquid injection components have identical structures, all employing a detachable short section structure, including a riser section. The inner wall of the riser section is provided with a replaceable wear-resistant liner. A component housing 20 is arranged around the outside of the riser section, forming an annular pressure equalization cavity 21 between the component housing 20 and the riser section. The annular pressure equalization cavity 21 is provided with a flow guiding or damping structure 23.

[0036] The component housing 20 is provided with an injection inlet 22 that communicates with the annular equalizing cavity 21. The outer end of the injection inlet 22 is connected to a liquid source containing micro-nano bubbles, and the inner end opening is connected to the annular equalizing cavity 21.

[0037] Specifically, the micro-nano bubble carrier liquid source includes a micro-nano bubble generating unit 5 arranged in the bypass carrier liquid circuit. The bypass carrier liquid circuit transports clean carrier liquid that does not contain large-particle-size ore or carrier liquid after solid-liquid isolation. The carrier liquid can be obtained from the liquid phase in the riser through a wear-resistant liquid extraction and solid-liquid isolation structure, or it can be supplied by an independent clean seawater circuit.

[0038] In this embodiment, the micro / nano bubble generating unit 5 includes a liquid inlet 10, a gas inlet 11, a gas-liquid premixing or dissolved gas chamber 12, a constriction throat 13, a swirling shear section 14 located downstream of the throat, a diffuser section 15, a back pressure regulating element 16, and a pressure sensing element 17. The gas-liquid premixing or dissolved gas chamber 12, the constriction throat 13, the swirling shear section 14, and the diffuser section 15 are arranged sequentially and connected along the flow direction. The gas-liquid premixing or dissolved gas chamber is provided with a liquid inlet 10 and a gas inlet 11, and the back pressure regulating element 16 is located at the outlet of the diffuser section 15.

[0039] Clean carrier liquid or carrier liquid after solid-liquid separation enters through carrier liquid inlet 10, and gas generated by gas source 6 enters gas-liquid premixing or dissolved gas chamber 12 through gas inlet 11. The premixed fluid forms a pressure drop and gas nucleus through the contraction throat 13, and then enters the swirling shear section 14. The swirling shear section 14 is located downstream of the throat to avoid the blades occupying the minimum flow cross section and to reduce cavitation concentration. The diffuser section 15 performs pressure recovery and bubble redispersion, and the back pressure regulating element 16 is used to match the outlet pressure of the generating unit with the pressure required by the annular equalizing chamber 21 to avoid the main lifting slurry being directly introduced into the throat.

[0040] Pressure sensing element 17 detects at least the inlet and outlet pressures of the generating unit, and adds throat pressure if necessary. The micro / nano bubble generating unit 5 is calibrated for cavitation conditions based on absolute pressure and actual seawater vapor pressure. If a dissolved gas-depressurization precipitation route is used, the gas first dissolves in the high-pressure carrier liquid and is then controlled to precipitate before entering the nozzle branch or at the nozzle opening; if a direct gas-liquid shear route is used, back pressure suppresses the formation of large gas masses. Both routes can be used in conjunction with an annular equalizing chamber.

[0041] The micro / nano bubbles referred to in this specification are micron-sized and / or nano-sized dispersed bubbles contained in a gas-containing carrier liquid; it is not required that all bubbles be smaller than 1 micrometer. Bubble size should be characterized under specified sampling pressure, temperature, salinity, and measurement methods. Preferably, it is described by a combination of the median volume diameter D50 under injection point pressure conditions, gas molar flow rate or standard state gas volume, and local gas holdup.

[0042] When the micro-nano bubble generating unit 5 is working, the gas and the carrier liquid are mixed under conditions higher than the absolute pressure inside the tube at the corresponding injection position, and then sequentially undergo premixing or gas dissolution, throttling nucleation, swirling shearing and diffusion stabilization to form a carrier liquid containing micro-nano bubbles that maintains the injection pressure.

[0043] Multiple nozzle assemblies 24 are arranged around the circumference of the annular equalizing chamber 21. Each nozzle assembly 24 includes a throttling structure and a one-way check valve structure 25. The design flow pressure drop of the nozzle assembly 24 is not less than three times the maximum circumferential pressure deviation of the annular equalizing chamber 21, and preferably the effective flow area of ​​the annular equalizing chamber is not less than five times the sum of the minimum flow areas of all nozzles. The inlet of the nozzle assembly 24 is connected to the annular equalizing chamber 21, and the outlet of the nozzle assembly 24 is configured such that the injected jet has a radial component toward the center of the pipe, a tangential component, and an axial component in the same direction as the mainstream slurry in the riser pipe 3.

[0044] When the difference between the absolute pressure in the annular equalizing chamber 21 and the absolute pressure in the riser pipe 3 is not less than the sum of the opening pressure difference of the one-way check structure, the design flow pressure drop of the nozzle assembly 24, and the safety pressure difference margin, the nozzle assembly 24 can open and form a stable injection; when the absolute pressure difference is lower than the opening pressure difference of the one-way check structure or when the main pressure rises abnormally, the check structure closes, blocking the backflow of the main slurry to the annular equalizing chamber 21, and the corresponding branch is cut off by the segmented isolation valve 53.

[0045] Multiple nozzle assemblies 24 are arranged evenly or in groups along the circumference. The number of nozzles can be 6-16, preferably 8-12; the number is not an independent innovation point, but is determined together with the pipe diameter, target penetration radius, allowable orifice ratio, and branch flow resistance. The inner end of each nozzle assembly 24 is flush with or recessed into the inner wall of the riser pipe to replace the wear-resistant liner, thereby reducing the frontal impact of the ore.

[0046] The injection direction is defined using two independent angles: The tangential deflection angle β is the angle between the jet direction and the inward radial direction within the pipe cross-section. A small β angle weakens cross-sectional mixing, while a large β angle may cause high-density particles to accumulate towards the pipe wall. For example... Figure 3 As shown, the axes of each nozzle in the cross-section are deflected by an angle β relative to the inward radial direction, so that the tangential components of each jet are aligned, thereby forming a controlled overall rotational trend.

[0047] The axial angle γ is the angle between the jet direction and the central axis of the riser. For example... Figure 4 As shown, the jet direction forms an angle γ with respect to the riser axis, and the axial component is aligned with the mainstream slurry flow. When γ is close to 0 degrees, axial momentum is dominant and lateral penetration is insufficient; when γ is close to 90 degrees, radial penetration is enhanced but downstream momentum decreases.

[0048] In summary, the spray direction setting of the nozzle assembly 24 enables tangential mixing of the jet through the β angle, while simultaneously retaining the penetration component towards the tube center and the downstream axial momentum through the γ angle. Preferably, the β angle is 10-35 degrees and the γ angle is 20-70 degrees; the actual values ​​are determined by the tube diameter, nozzle momentum ratio, solid phase concentration, and allowable wear rate.

[0049] In this embodiment, the injection inlet 22 can be a single inlet, multiple inlets, or a tangential inlet. The flow guiding or damping structure 23 extends the circumferential flow path and prevents the inlet jet from directly impacting adjacent nozzles.

[0050] In this embodiment, the annular equalizing cavity 21 can be a single-layer annular cavity, a double-layer annular cavity, an annular cavity with porous baffles, or a multi-inlet symmetrical annular cavity, as long as it is compatible with the branch resistance dominance and differential pressure control.

[0051] In this embodiment, the micro-nano bubble generating unit 5 may employ Venturi-cyclone, pressurized dissolved gas-controlled precipitation, porous media shearing, or a combination thereof, but is preferably located in a bypass liquid-carrying loop that does not contain large-diameter ore.

[0052] In this embodiment, the nozzle assembly 24 can be a fixed angle, an adjustable angle, or a group of alternating angles; adjacent nozzles can have the same tangential direction, or they can be divided into axially spaced groups with opposite rotation directions to suppress excessive overall swirl.

[0053] In this embodiment, the gas source 6 can be air, nitrogen, inert gas, or other gases that meet safety and environmental requirements; whether or not to add a surfactant should be evaluated for compatibility with the marine environment, and surfactants are not a necessary feature of this invention.

[0054] Example 2:

[0055] This embodiment provides a specific configuration of the nozzle assembly 24, forming an anti-backflow, replaceable, and wear-resistant nozzle.

[0056] like Figure 6 As shown, the nozzle assembly 24 is installed in the nozzle mounting base 70 and locked in place by the removable sleeve 71.

[0057] The throttling structure uses a throttling element 72 to form the main branch resistance that can be repeatedly calibrated.

[0058] The one-way check structure includes a check valve core 73 and an elastic reset element 74. The check valve core 73 remains closed under the action of the elastic reset element 74. When the difference between the absolute pressure in the annular equalizing chamber 21 and the absolute pressure in the riser pipe 3 is higher than the opening pressure differential of the one-way check structure, the check valve core 73 opens. When the difference between the absolute pressure in the annular equalizing chamber 21 and the absolute pressure in the riser pipe 3 is lower than the opening pressure differential of the check structure, the check valve core 73 closes.

[0059] The wear-resistant nozzle 75 is made of carbide, engineering ceramic, surface hardened alloy or composite wear-resistant material.

[0060] The throttling element 72 and the wear-resistant nozzle 75 are separately arranged, allowing the flow calibration element and the abrasion element to be replaced separately. When the check valve core 73 is arranged downstream of the throttling element, it can reduce the transmission of main pipe pressure pulsation to the pressure equalization chamber; when arranged upstream of the throttling element, it facilitates the protection of the throttling orifice. Both arrangements are equivalent embodiments of the present invention.

[0061] Example 3:

[0062] Based on Embodiment 1 or Embodiment 2, this embodiment provides a cavity pressure measuring point 29 on the component housing 20 for measuring the pressure of the annular equalizing cavity 21, and a pipe pressure measuring point 28 on the lift tube short section for measuring the pressure inside the pipe. The pipe pressure measuring point 28 and the cavity pressure measuring point 29 use the same pressure reference and are located in the same or adjacent axial positions as much as possible.

[0063] The control system 9 controls the gas source pressure, the speed of the liquid carrier pump, or the regulating valve based on the absolute pressure difference between the two, so that any injection section satisfies the following formula:

[0064] In the formula, p a,i The absolute pressure of the i-th segment of the annular equalizing chamber is... p p,i To increase the absolute pressure inside the pipe in the i-th segment, Δp open ,i is the differential pressure at which the return structure is activated. Δp r ,i is the pressure difference required for the carrier fluid to pass through the throttling structure and the nozzle, Δ p safe ,i is the safety differential pressure margin to resist pressure fluctuations and measurement errors. When the above conditions are not met or the main pressure suddenly increases, the check valve closes, and the segmented isolation valve 53 cuts off the corresponding branch.

[0065] To ensure that the pressure stabilizing effect of the annular pressure equalizing chamber truly translates into consistent flow rates across all nozzles, the design pressure drop of the nozzle branch should preferably be no less than three times the maximum circumferential pressure deviation of the annular pressure equalizing chamber; more preferably, the effective flow area of ​​the annular pressure equalizing chamber should be no less than five times the sum of the minimum flow areas of all nozzles. Each nozzle can be graded for flow resistance using a replaceable throttling structure, allowing it to recover its calibrated flow rate even after wear.

[0066] When calibrating the nozzle branches, the flow-pressure differential curves of each nozzle are recorded, and the flow variation coefficient is controlled within the design limit by replacing the throttling device.

[0067] The design calculation example is as follows: Let the inner diameter of a certain injection section riser pipe be... D 300 mm, absolute pressure of the main pipe p p The pressure is 51.8 MPa, the apparent flow velocity inside the pipe is 3.5 m / s, and the solid volume concentration is 10%. Eight nozzles are selected, and the effective flow area of ​​the annular equalizing chamber is eight times the sum of the minimum flow areas of all nozzles.

[0068] If the check valve opening pressure differential is 0.05 MPa, the nozzle and throttling device design pressure drop is 0.35 MPa, and the safety margin considering pipe pressure fluctuations, measurement errors, and control hysteresis is 0.15 MPa, then the target absolute pressure of the annular equalizing chamber should not be less than:

[0069] The design pressure of the micro-nano bubble generating unit and the gas supply pipeline should be based on 52.35 MPa, with additional consideration given to liquid pipe loss and equipment safety factor.

[0070] If the maximum circumferential pressure deviation of the annular equalizing chamber is calculated to be 0.08 MPa, then the branch pressure drop of 0.35 MPa is approximately 4.4 times that, which satisfies the preferred condition of branch resistance being dominant.

[0071] Example 4:

[0072] Based on Embodiment 1, Embodiment 2, or Embodiment 3, this embodiment provides the specific settings of the control system 9.

[0073] like Figure 7 and Figure 8 As shown, the control system 9 includes a monitoring unit 30, a control unit 40, and an execution unit 50.

[0074] Downstream of each gas-liquid injection assembly is a monitoring unit 30 for acquiring pressure, delivery flow rate, solid phase concentration, and gas phase state. In this embodiment, the monitoring unit 30 monitors the gas phase state using impedance, acoustic, differential pressure chromatography, sampling measurement, or estimation by a pressure-flow model. It is not limited to using an optical particle size analyzer to directly measure opaque, high-concentration slurry.

[0075] The control unit 40 includes a state estimation module 41, a target generation module 42, a control module 43, and a safety interlock module 44. The state estimation module 41 filters sensor drift and multiphase flow pulsation, the target generation module 42 provides the target differential pressure and gas volume for each segment according to the safety delivery window, the control module 43 outputs execution commands, and the safety interlock module 44 independently judges overpressure, backflow, flow loss, and sensor failure.

[0076] The execution unit 50 includes a segmented isolation valve 53 corresponding to each gas-liquid injection component, a liquid booster pump 52 installed in the liquid supply pipeline upstream of the liquid inlet 10, and a gas regulating valve 51 installed in the gas supply pipeline upstream of the gas inlet 11; when an adjustable nozzle is used, it also includes an angle actuator 54.

[0077] The control unit 40 adjusts the gas flow rate, liquid flow rate or injection pressure difference of each gas-liquid injection component according to the output of the monitoring unit 30. By adjusting the output pressure of the liquid source containing micro-nano bubbles, the difference between the absolute pressure in the cavity and the absolute pressure in the pipe is not less than the sum of the opening pressure difference of the one-way check structure, the design flow pressure drop of the nozzle assembly 24 and the safety pressure difference margin.

[0078] The safety interlock has a higher priority than normal regulation. When the rate of increase of the main pressure of riser pipe 3, the duration of insufficient differential pressure, or the decrease of the liquid flow rate exceeds the calibrated threshold, the safety interlock module 44 closes the gas regulating valve 51 and the segment isolation valve 53, and maintains short-term flushing of the liquid pump.

[0079] Control system 9 can achieve segmented pressure matching and closed-loop control, specifically: The control system 9 calculates the difference between the absolute pressure in the annular equalization chamber 21 and the absolute pressure in the riser pipe 3 for each injection section, and combines this with the downstream monitoring unit 30 to estimate the gas phase state, pressure fluctuations, and deposition risks. If the downstream gas phase state is lower than the target and the pressure fluctuation does not exceed the limit, the gas or liquid flow rate in that section is gradually increased; if the pressure fluctuation, gas holdup, or near-wall solid concentration exceeds the limit, the injection rate is reduced or the section is closed through the segment isolation valve 53.

[0080] Example 5:

[0081] This embodiment discloses a method for lifting a deep-sea mining pipeline using a combination of micro-nano bubble hydraulic and pneumatic systems, including the following steps: (1) Start the ore lifting pump 2 to make the solid-liquid slurry form a basic hydraulic transport state in the lift pipe 3 that is higher than the critical sedimentation rate and lower than the allowable wear rate of the equipment; Read the absolute pressure inside the pipe of the section to be injected, first start the liquid booster pump 52 to establish liquid circulation, and then add gas through the gas regulating valve 51 and gas inlet 11 to gradually increase the outlet pressure of the micro-nano bubble generating unit 5 to the target value. (3) When the pressure difference between the annular equalizing chamber and the pressure inside the pipe reaches the sum of the check opening pressure difference, the nozzle design pressure drop and the safety margin, the segmented isolation valve 53 is opened so that the liquid containing micro-nano bubbles is injected circumferentially through the annular equalizing chamber 21 and the nozzle assembly 24. (4) Limit the flow deviation of each nozzle by the flow distribution relationship dominated by the branch resistance, and use the radial-tangential-axial three-component jet to promote the diffusion of the gas phase in the cross section; (5) Adjust the gas flow rate, liquid flow rate and injection pressure difference segment by segment according to the pressure, gas phase state, solid phase concentration and pressure fluctuation of each segment, so that the local gas phase state is kept within the pre-calibrated stable delivery window; (6) When shutting down, first cut off the gas supply, then flush the generating unit, annular equalizing chamber and nozzle with clean carrier liquid, and then close the segmented isolation valve; when the main pressure rises abnormally, the check structure and safety interlock will perform rapid isolation. (7) After the slurry reaches the water surface working platform 7, it enters the gas-liquid-solid separation device 8. The separated gas is discharged or recycled according to safety requirements, the solid minerals enter the subsequent treatment, and the liquid phase is recycled or discharged after treatment.

[0082] The startup sequence is as follows: main hydraulic transport stabilizes, liquid circulation is established, pressure equalization chamber is pressurized, differential pressure conditions are met, gas is slowly added, and the target section enters closed loop. The shutdown sequence is as follows: reduce gas flow, cut off gas supply, liquid flushing, close isolation valve, and stop liquid pump. This sequence reduces the probability of gas stagnation and solids entering the nozzle.

[0083] The above embodiments are only used to illustrate and not limit the technical solutions of the present invention. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the present invention without departing from the spirit and scope of the present invention. Any modifications or partial substitutions should be covered within the scope of the claims of the present invention.

[0084] If the terms "first" or "second" are used in this document to define components, those skilled in the art should know that the use of "first" or "second" is merely for the convenience of describing the invention and simplifying the description, and unless otherwise stated, the above terms have no special meaning.

[0085] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0086] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

Claims

1. A deep-sea mining micro-nano bubble hydraulic-pneumatic combined pipeline lifting system, comprising a ore-lifting pump (2) and a lifting pipe (3) connected to the ore-lifting pump (2), characterized in that: At least one gas-liquid injection component is arranged in the flow direction downstream of the ore pump on the riser pipe (3); The gas-liquid injection assembly includes an annular equalizing chamber (21) arranged around the riser tube (3), an injection inlet (22) communicating with the annular equalizing chamber (21), and a plurality of nozzle assemblies (24) arranged around the circumference of the annular equalizing chamber (21). The inlet of the nozzle assembly (24) is connected to the annular equalizing chamber (21), and the outlet of the nozzle assembly (24) is configured such that the injected jet has a radial component toward the tube center, a tangential component, and an axial component in the same direction as the mainstream of the slurry in the riser (3); each nozzle assembly (24) includes a throttling structure and a one-way check structure (25), the one-way check structure (25) being used to allow the carrier liquid containing micro-nano bubbles to be injected unidirectionally from the annular equalizing chamber (21) into the riser, and to prevent the slurry in the riser from entering the nozzle assembly (24) and the annular equalizing chamber (21) in reverse. The injection inlet (22) is connected to a liquid source containing micro-nano bubbles; It also includes a control system, which adjusts the liquid source containing micro-nano bubbles according to the absolute pressure difference between the annular equalizing chamber (21) and the riser pipe (3) so that the absolute pressure difference between the annular equalizing chamber (21) and the riser pipe (3) is not less than the sum of the opening pressure difference of the one-way check structure, the design flow pressure drop of the nozzle assembly (24) and the safety pressure difference margin.

2. The deep-sea mining micro-nano bubble hydraulic-pneumatic combined pipeline lifting system according to claim 1, characterized in that: The micro-nano bubble carrier liquid source includes a micro-nano bubble generating unit (5) arranged in the bypass carrier liquid circuit. The bypass carrier liquid circuit transports clean carrier liquid that does not contain large-diameter ore or carrier liquid that has been separated by solid and liquid.

3. The deep-sea mining micro-nano bubble hydraulic-pneumatic combined pipeline lifting system according to claim 2, characterized in that: The micro-nano bubble generating unit (5) includes a gas-liquid premixing or dissolved gas chamber (12), a constriction throat (13), a swirling shear section (14), and a diffuser section (15) arranged sequentially and connected along the flow direction. The gas-liquid premixing or dissolved gas chamber is provided with a liquid inlet (10) and a gas inlet (11). The outlet of the diffuser section (15) is provided with a back pressure regulating element (16) for maintaining the outlet pressure of the generating unit. It also includes a pressure detection element (17) for detecting the inlet and outlet pressures of the micro-nano bubble generating unit (5).

4. The deep-sea mining micro-nano bubble hydraulic-pneumatic combined pipeline lifting system according to claim 1, characterized in that: The design flow pressure drop of the nozzle assembly (24) is not less than 3 times the maximum circumferential pressure deviation of the annular equalizing chamber (21).

5. The deep-sea mining micro-nano bubble hydraulic-pneumatic combined pipeline lifting system according to claim 4, characterized in that: The jet direction of the nozzle assembly (24) forms a tangential deflection angle β of 10-35 degrees relative to the inward radial direction within the cross section of the riser tube (3), and forms an axial angle γ of 20-70 degrees relative to the central axis of the riser tube (3).

6. The deep-sea mining micro-nano bubble hydraulic-pneumatic combined pipeline lifting system according to any one of claims 1-5, characterized in that: The gas-liquid injection assembly is a detachable short section structure, including a riser tube short section and an assembly housing (20) arranged around the outside of the riser tube short section. The annular pressure equalization cavity (21) is formed between the inner wall of the assembly housing (20) and the outer wall of the riser tube short section. The annular pressure equalization cavity 21 is provided with a flow guiding or damping structure (23). The component housing (20) is provided with a cavity pressure measuring point (29) for measuring the pressure of the annular equalizing cavity (21), and the lift tube short section is provided with a pipe pressure measuring point (28) for measuring the pressure inside the pipe. The cavity pressure measuring point (29) and the pipe pressure measuring point (28) are located at the same or adjacent axial positions.

7. The deep-sea mining micro-nano bubble hydraulic-pneumatic combined pipeline lifting system according to claim 6, characterized in that: The control system includes a monitoring unit (30), a control unit (40), and an execution unit; Downstream of each gas-liquid injection assembly is a monitoring unit (30) for characterizing at least two of the following: pressure, delivery flow rate, solid concentration, and gas phase state. The execution unit includes a segmented isolation valve (53) corresponding to each gas-liquid injection component, a liquid booster pump (52) installed in the liquid supply pipeline upstream of the liquid inlet (10), and a gas regulating valve (51) installed in the gas supply pipeline upstream of the gas inlet (11). The control unit (40) adjusts the gas flow rate, liquid flow rate or injection pressure difference of each gas-liquid injection component according to the absolute pressure difference between the annular equalizing chamber (21) and the riser pipe (3) and the output of the monitoring unit (30).

8. The deep-sea mining micro-nano bubble hydraulic-pneumatic combined pipeline lifting system according to claim 7, characterized in that: The control unit (40) also includes a safety interlock module (44). When the main pressure rise rate of the riser pipe (3), the duration of insufficient differential pressure, or the decrease in the liquid flow rate exceeds the calibrated threshold, the safety interlock module (44) closes the gas regulating valve (51) and the segment isolation valve (53) and maintains the liquid pump for short-term flushing.

9. The deep-sea mining micro-nano bubble hydraulic-pneumatic combined pipeline lifting system according to claim 7, characterized in that: The control system is used to achieve segmented pressure matching and closed-loop control, specifically: The riser pipe (3) is defined as multiple injection sections according to the gas-liquid injection component. The control system (9) calculates the difference between the absolute pressure of the annular equalization chamber (21) of each injection section and the absolute pressure inside the riser pipe (3), and calculates the gas phase state, pressure fluctuation and deposition risk in conjunction with the downstream monitoring unit (30). If the downstream gas phase state is lower than the target and the pressure fluctuation does not exceed the limit, the gas or liquid flow rate of the corresponding injection section is gradually increased. If the pressure fluctuation, gas holdup or near-wall solid concentration exceeds the limit, the injection volume is reduced or the corresponding injection section is closed.

10. A method for lifting a deep-sea mining micro-nano bubble hydraulic-pneumatic combined pipeline, based on the deep-sea mining micro-nano bubble hydraulic-pneumatic combined pipeline lifting system according to any one of claims 1-9, characterized in that... Includes the following steps: The basic hydraulic transport of solid-liquid slurry is established in the riser pipe (3) by the ore pump (2); the absolute pressure inside the pipe at the location of the gas-liquid injection component to be put into the pipe is obtained; and a micro-nano bubble-containing carrier liquid with a pressure higher than the absolute pressure inside the riser pipe (3) is prepared in the bypass carrier liquid circuit. After the absolute pressure difference between the annular equalizing chamber (21) and the absolute pressure difference between the riser pipe (3) reaches the sum of the opening pressure difference of the one-way check structure, the design flow pressure drop of the nozzle, and the safety pressure difference margin, the corresponding segmented isolation valve (53) is opened, and the micro-nano bubble-containing carrier liquid is injected into the riser pipe (3) through the annular equalizing chamber (21) and each nozzle assembly (24); and the gas flow rate, carrier liquid flow rate, or injection pressure difference is adjusted according to at least two of the pressure downstream of the injection section, the delivery flow rate, the solid phase concentration, and the gas phase state.

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