Design optimization method of deep-sea mineral resource collection head based on Coanda effect

Abstract

This scheme provides a design optimization method for a deep-sea mineral resource collection head based on the Coanda effect, including the following steps: determining the collection target parameters; constructing a particle size force model; determining the initial parameters of the deep-sea mineral resource collection head; optimizing the design parameters of the deep-sea mineral resource collection head. The design optimization method designs the deep-sea mineral resource collection head according to actual mining needs and mineral characteristics, thereby improving the collection effect of the deep-sea mineral resource collection head.

Description

Technical Field

[0001] The present application relates to the field of ore collection head design, and in particular to a design optimization method for a deep-sea mineral resource ore collection head based on the Coanda effect. Background Art

[0002] In the field of deep-sea mining technology, with the growing demand for deep-sea mineral resources, how to efficiently, stably and environmentally friendly collect these resources has become an urgent problem to be solved. As an important polymetallic mineral resource, deep-sea mineral resources are widely distributed on the seabed, and their collection technology has always been a research hotspot in the field of marine engineering. Traditional deep-sea mineral resource collection methods often have problems such as low efficiency, high energy consumption, and great impact on the seabed environment. Therefore, it is particularly important to develop new and efficient collection methods.

[0003] The deep-sea mineral resource collection method based on the Coanda effect came into being in this context. The Coanda effect, also known as the wall adhesion effect or boundary layer adsorption effect, is a fluid dynamics phenomenon. When a fluid passes around a curved surface, if the fluid speed is large enough, it will flow along the surface under the influence of the surface and even remain attached when the curvature changes.

[0004] Traditional deep-sea mining equipment often has difficulty in accurately controlling the flow field distribution during the collection process, resulting in low efficiency in collecting mineral resources and easy damage to the seabed environment. The deep-sea mineral resource collection method based on the Coanda effect can achieve precise control of the flow field by accurately designing and optimizing the parameters of the collection device, such as the width D of the jet port, the radius of curvature R of the Coanda surface, the height H from the ground, and the jet speed U, thereby improving the collection efficiency of mineral resources. At the same time, this method can also reduce equipment energy consumption and reduce interference with the seabed environment, and has high environmental protection and economic benefits.

[0005] However, in practical applications, the deep-sea mineral resource collection method based on the Coanda effect still faces many challenges. How to accurately predict and simulate flow field distribution and particle movement, how to optimize device design to achieve the best collection effect, and how to ensure the stability and reliability of the device in complex marine environments are all issues that need further research and resolution.

[0006] Therefore, in-depth research and optimization of this method is of great significance to promoting the development of deep-sea mining technology. Summary of the invention

[0007] The embodiment of the present application provides a design optimization method for a deep-sea mineral resource collection head based on the Coanda effect, which designs a deep-sea mineral resource collection head based on the target collection output, mineral properties and flow field characteristics, thereby improving the collection effect of the deep-sea mineral resource collection head.

[0008] In a first aspect, the present application provides a method for optimizing the design of a deep-sea mineral resource collection head based on the Coanda effect, comprising the following steps:

[0009] S1: Determine the acquisition target parameters:

[0010] Determine target mining yield, ore particle size, abundance, particle density, and sediment viscosity;

[0011] S2: Construct particle size force model:

[0012] The critical lifting force is determined based on the ore particle size, particle density and fluid density. The lift is determined based on the fluid density, flow area, lift coefficient and jet velocity. The particle size force model is constructed based on the critical lifting force and lift:

[0013] S3: Determine the initial parameters of the deep-sea mineral resource set mine head:

[0014] Determine the jet velocity based on the particle size force model, determine the width and jet flow rate of the deep-sea mineral resource collection head based on the target collection output, jet velocity and abundance, determine the jet port width of the deep-sea mineral resource collection head based on the jet flow rate and jet velocity, determine the height of the deep-sea mineral resource collection head from the ground based on the sediment viscosity, ore particle size and critical lifting force, and determine the curvature radius of the Coanda surface plate of the deep-sea mineral resource collection head based on the fluid density, flow field action length and pressure difference on both sides of the curved plate;

[0015] S4: Optimize the design parameters of deep-sea mineral resource collection ore heads:

[0016] Based on the initial parameters, a clear water flow field simulation is carried out to obtain the simulation results, and based on the simulation results, the initial parameters of the deep-sea mineral resource set mine are adjusted to determine the design parameters.

[0017] The main contributions and innovations of the present invention are as follows:

[0018] The embodiment of the present application establishes a particle size force model and flow field simulation optimization to achieve quantitative matching of key parameters such as jet velocity and curvature radius, ensures effective detachment of ore particles based on the critical lifting force formula, and adjusts structural parameters in combination with fluid mechanics simulation to keep the ore collecting head stable and efficient in complex seabed terrain, and optimize the device design to achieve the best collection effect. In addition, the method also supports flexible adaptation of different mineral characteristics (such as particle size and density), providing technical support for the large-scale mining of resources such as deep-sea polymetallic nodules and cobalt-rich crusts.

[0019] Details of one or more embodiments of the present application are set forth in the following drawings and description to make other features, objects, and advantages of the present application more readily apparent. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0021] Figure 1 It is a flow chart of a method for designing and optimizing a deep-sea mineral resource collection head based on the Coanda effect according to an embodiment of the present application;

[0022] Figure 2 It is a structural schematic diagram of a deep-sea mineral resource collection head based on the Coanda effect according to an embodiment of the present application;

[0023] Figure 3 It is a parameter diagram of a deep-sea mineral resource set mine head based on the Coanda effect according to an embodiment of the present application;

[0024] Figure 4 This is a comparison chart of experimental and simulation data.

[0025] Figure 5 is the different positions of the curved plate (L 1 L 2 L 3 )’s pressure and pressure gradient distribution diagram. DETAILED DESCRIPTION

[0026] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with one or more embodiments of this specification. Instead, they are merely examples of devices and methods consistent with some aspects of one or more embodiments of this specification as detailed in the appended claims.

[0027] It should be noted that: in other embodiments, the steps of the corresponding method are not necessarily performed in the order shown and described in this specification. In some other embodiments, the steps included in the method may be more or less than those described in this specification. In addition, a single step described in this specification may be decomposed into multiple steps for description in other embodiments; and multiple steps described in this specification may be combined into a single step for description in other embodiments.

[0028] Embodiment 1

[0029] like Figure 1 As shown, this scheme provides a design optimization method for a deep-sea mineral resource collection head based on the Coanda effect, including the following steps:

[0030] S1: Determine the acquisition target parameters:

[0031] Determine target mining yield, ore particle size, abundance, particle density, and sediment viscosity;

[0032] S2: Construct particle size force model:

[0033] The critical lifting force is determined based on the ore particle size, particle density and fluid density. The lift is determined based on the fluid density, flow area, lift coefficient and jet velocity. The particle size force model is constructed based on the critical lifting force and lift:

[0034] S3: Determine the initial parameters of the deep-sea mineral resource set mine head:

[0035] Determine the jet velocity based on the particle size force model, determine the width and jet flow rate of the deep-sea mineral resource collection head based on the target collection output, jet velocity and abundance, determine the jet port width of the deep-sea mineral resource collection head based on the jet flow rate and jet velocity, determine the height of the deep-sea mineral resource collection head from the ground based on the sediment viscosity, ore particle size and critical lifting force, and determine the curvature radius of the Coanda surface plate of the deep-sea mineral resource collection head based on the fluid density, flow field action length and pressure difference on both sides of the curved plate;

[0036] S4: Optimize the design parameters of deep-sea mineral resource collection ore heads:

[0037] Based on the initial parameters, a clear water flow field simulation is carried out to obtain the simulation results, and based on the simulation results, the initial parameters of the deep-sea mineral resource set mine are adjusted to determine the design parameters.

[0038] This scheme provides a design optimization method for deep-sea mineral resource collection heads based on the Coanda effect. The deep-sea mineral resource collection heads based on the Coanda effect optimize the collection efficiency through the fluid wall effect and the low-pressure adsorption principle. The structural design of the deep-sea mineral resource collection heads based on the Coanda effect is as follows: Figure 2 As shown, the deep-sea mineral resource collection head based on the Coanda effect includes a Coanda surface plate arranged on a curved surface, wherein the Coanda surface plate is arranged off the ground to form a collection cavity, and a jet port is arranged at the entrance of the collection cavity. Specifically, when the deep-sea mineral resource collection head based on the Coanda effect is used for collection, a high-pressure pump injects a jet formed by seawater into the collection cavity from the jet port at a set jet speed, and the jet flows tangentially along the curvature of the Coanda surface plate. When the jet flows along the curved surface, the outer flow velocity is accelerated. According to the Bernoulli principle, the static pressure of the fluid is reduced to form a long strip of low pressure area. The pressure difference generated by the long strip of low pressure area exerts a normal adsorption force on the mineral resources. The adsorption force causes the mineral resources to separate from the seabed and enter the collection cavity with the secondary flow induced by the jet. At the same time, light sediments are carried away from the collection area by the mainstream due to their low density.

[0039] like Figure 3As shown, the initial parameters of the deep-sea mineral resource collection head based on the Coanda effect include jet velocity U, jet orifice width D, height from the ground H and Coanda surface plate curvature radius R, wherein the jet orifice width D refers to the width of the jet orifice, the jet velocity U refers to the velocity of the jet in the jet orifice, the height from the ground H refers to the height of the lowest position of the Coanda surface plate from the ground, and the Coanda surface plate curvature radius R is the curvature radius of the Coanda surface plate. This scheme designs a deep-sea mineral resource collection head based on the target collection output, mineral properties and flow field characteristics, and introduces the force analysis of particles at critical positions in the design method to achieve the best collection effect.

[0040] Specifically, in step S1, target collection parameters including target collection output, ore particle size, abundance, particle abundance and sediment viscosity are determined according to the actual deep-sea mineral resource collection needs, where the target collection constant It refers to the output of deep-sea mineral resources that need to be collected, and the ore particle size refers to the particle diameter of the ore of deep-sea mineral resources that need to be collected. , abundance Refers to the distribution density and particle density of deep-sea mineral resources that need to be collected Refers to the density between particles of the ore of deep-sea mineral resources collected. It should be noted that the particle diameter is determined by the average particle size of the particle size distribution curve obtained through on-site sampling.

[0041] In step S2:

[0042] In the step of "Determining the critical lifting force based on ore particle size, particle density and fluid density", the critical lifting force refers to the lifting force that just offsets the force between the particles and the wall of the ore collecting cavity. The calculation formula of the critical lifting force is as follows:

[0043] ;

[0044] in is the critical lifting force, is the particle diameter, is the particle density, is the fluid density, and g is the gravity parameter. It should be noted that when determining the initial parameters, the fluid density Set it as the preset value, and adjust it according to the fluid conditions of the actual clean water flow field when optimizing the design parameters later.

[0045] In the step "Determine lift based on fluid density, flow area, lift coefficient, and jet velocity", lift refers to the lifting force on the particles, where the lift calculation formula is as follows:

[0046] ;

[0047] ;

[0048] in is the lift, U is the jet velocity, is the lift coefficient obtained from experience, is the flow area, α is the pressure correction factor, is the fluid density, and r is the particle radius. It should be noted that due to the difference between the theoretical model and the actual model, this solution adjusts the pressure distribution in the lift calculation through the pressure correction factor, which is generally an empirical value determined based on historical data. The headstream area refers to the effective projected area of ​​the particle in the direction of fluid flow, which is calculated by the particle radius.

[0049] In the step of "constructing a particle size force model based on critical lift and lift", it is necessary to ensure that the lift is greater than the critical lift so that the jet can drive the movement of the particles. Therefore, the particle size force model is that the lift is not less than the critical lift.

[0050] In step S3:

[0051] In the step of "Determining the width and jet flow rate of the deep-sea mineral resource set based on the target collection output, jet velocity, and abundance", the formula for determining the width of the deep-sea mineral resource set is as follows:

[0052] ;

[0053] Where W is the width of the deep-sea mineral resource cluster head, is the target collection yield, U is the jet velocity, is the volume concentration of ore particles, For abundance.

[0054] In the step of "determining the jet flow rate of the deep-sea mineral resource set mine head based on the target collection output, jet velocity, and abundance", the formula for determining the jet flow rate of the deep-sea mineral resource set mine head is as follows:

[0055] ;

[0056] in is the jet flow rate, To collect the target yield, For abundance, is the volume concentration of ore particles.

[0057] In some embodiments, the volume concentration of the ore particles The value of is 10%~20%, and the volume concentration of ore particles can be randomly confirmed when calculating the initial parameters.

[0058] In the step of "determining the jet opening width of the deep-sea mineral resource set mine head based on the jet flow rate and jet velocity", the formula for determining the jet opening width of the deep-sea mineral resource set mine head is as follows:

[0059] ;

[0060] Where U is the jet velocity, is the jet flow rate, and D is the jet orifice width.

[0061] In the step of "determining the height above ground of the head of a deep-sea mineral resource cluster based on sediment viscosity, ore particle size and critical lifting force", the particle stripping shear force is calculated based on the sediment viscosity, and the height above ground of the head of a deep-sea mineral resource cluster is determined based on the relationship between the particle stripping shear force and the height above ground.

[0062] Specifically, the formula for calculating the particle peeling shear force based on the sediment viscosity is as follows:

[0063] ;

[0064] in is the sediment viscosity, is the velocity gradient, which is an empirical value.

[0065] Based on the principle of moment balance, the height of the deep-sea mineral resource collection head from the ground is determined by the moment of particle stripping shear force and critical lifting force. The height from the ground is the height to ensure that the particles can be separated from the bottom bed. The formula is as follows:

[0066] ;

[0067] Where H is the height above the ground, is the particle peeling shear force, is the particle diameter, is the critical lifting force.

[0068] In the step of "determining the curvature radius of the Coanda surface plate of the deep-sea mineral resource collection head based on the fluid density, the flow field action length and the pressure difference on both sides of the curved plate", the design of the curvature radius of the Coanda curved plate must meet the condition of maximizing the wall attachment effect to ensure that the jet flows stably along the curved surface without separation. Specifically, the formula for determining the curvature radius of the Coanda surface plate of the deep-sea mineral resource collection head is as follows:

[0069] ; ;

[0070] Where R is the radius of curvature of the Coanda surface plate, is the pressure difference on both sides of the Coanda surface plate, L is the flow field action length, is the experience value, is the fluid density, and U is the jet velocity U.

[0071] It should be noted that the pressure difference on both sides of the Coanda surface plate is calculated by the Bernoulli equation. In order to simplify the calculation, when calculating the initial parameters, it can be assumed that the flow rate on the separation side is close to 0. At this time, the simplified calculation formula for the pressure difference is: .

[0072] In addition, it should be noted that since the ratio of the flow field action length to the curvature radius of the Coanda surface plate will affect the wall adhesion stability, it is necessary to introduce as a correction factor.

[0073] Regarding step S4:

[0074] The simulation results are obtained by using CFD software to simulate the clear water flow field according to the initial parameters, wherein the simulation results refer to the numerical values ​​for evaluating the current deep-sea mineral resource collection effect, which are selected from one or more of flow velocity, pressure, and pressure gradient.

[0075] In the step of "adjusting the initial parameters of the deep-sea mineral resource set head based on simulation results to determine the design parameters", the pressure difference on both sides of the curved plate is compared to ensure the rationality of the design of the curvature radius of the curved plate and to ensure that the lift is greater than the critical lifting force.

[0076] In some embodiments, if the lift is insufficient, the curvature radius R is increased, the jet velocity U is increased, the height above the ground H is reduced, or the jet orifice width D is reduced to obtain optimized design parameters, and the clean water flow field simulation is re-performed based on the design parameters, and the design parameters corresponding to the best simulation results are selected to design the deep-sea mineral resource collection head.

[0077] Embodiment 2

[0078] The design optimization method for deep-sea mineral resource collection heads based on the Coanda effect provided in Example 1 of the present scheme is applied to design parameters of deep-sea mineral resource collection heads. It should be noted that this method can also be applied to the collection of various deep-sea mineral resources. Mineral resources include but are not limited to manganese nodules, polymetallic sulfides, cobalt-rich crusts, and phosphorite. By appropriately adjusting key parameters and device design, effective collection of deep-sea minerals of different types and particle sizes can be achieved.

[0079] Embodiment 3

[0080] Embodiment 1 of this solution provides a design optimization method for a deep-sea mineral resource collection head based on the Coanda effect. In order to verify the feasibility of the design optimization method, the application team conducted the following experiments:

[0081] The comparison results between the experimental and simulation data obtained by simulation using this design optimization method are shown in the figure below. Figure 4 As shown by Figure 4 The feasibility of the simulation design can be seen; at the same time, different positions (L 1 L 2 L 3 ) pressure and pressure gradient distribution as shown in Figure 5 As shown by Figure 5 You can see the instructions in L 2 The negative pressure decreases and the pressure gradient increases, which is the critical position of the particles.

[0082] Those skilled in the art should understand that the technical features of the above embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0083] The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A design optimization method for deep-sea mineral resource collection head based on Coanda effect, characterized in that: The following steps are involved: S1: Determine the acquisition target parameters: Determine target mining yield, ore particle size, abundance, particle density, and sediment viscosity; S2: Construct particle size force model: The critical lifting force is determined based on the ore particle size, particle density and fluid density. The lift is determined based on the fluid density, flow area, lift coefficient and jet velocity. The particle size force model is constructed based on the critical lifting force and lift: S3: Determine the initial parameters of the deep-sea mineral resource set mine head: Determine the jet velocity based on the particle size force model, determine the width and jet flow rate of the deep-sea mineral resource collection head based on the target collection output, jet velocity and abundance, determine the jet port width of the deep-sea mineral resource collection head based on the jet flow rate and jet velocity, determine the height of the deep-sea mineral resource collection head from the ground based on the sediment viscosity, ore particle size and critical lifting force, and determine the curvature radius of the Coanda surface plate of the deep-sea mineral resource collection head based on the fluid density, flow field action length and pressure difference on both sides of the curved plate; S4: Optimize the design parameters of deep-sea mineral resource collection ore heads: Based on the initial parameters, a clear water flow field simulation is carried out to obtain the simulation results. The pressure difference on both sides of the curved panel is compared to ensure the rationality of the design of the curvature radius of the curved panel and to ensure that the lift is greater than the critical lifting force. When the lift is insufficient, the curvature radius is increased, the jet speed is increased, the height from the ground is reduced, or the width of the jet port is reduced to obtain the optimized design parameters.

2. The design optimization method for deep-sea mineral resource collection head based on Coanda effect according to claim 1 is characterized in that: The jet mouth width refers to the width of the jet mouth, the jet velocity refers to the velocity of the jet in the jet mouth, the height above the ground refers to the height of the lowest position of the Coanda surface plate from the ground, the curvature radius of the Coanda surface plate is the curvature radius of the Coanda surface plate, the target collection constant refers to the output of deep-sea mineral resources that need to be collected, the ore particle size includes the particle diameter of the ore of the deep-sea mineral resources that need to be collected, and the abundance refers to the distribution density of the deep-sea mineral resources that need to be collected.

3. The design optimization method for deep-sea mineral resource collection head based on Coanda effect according to claim 1 is characterized in that: The calculation formula of critical lifting force is as follows: ； in is the critical lifting force, is the particle diameter, is the particle density, is the fluid density and g is the gravity parameter.

4. The design optimization method for deep-sea mineral resource collection head based on Coanda effect according to claim 1 is characterized in that: The formula for calculating lift is as follows: ； ； in is the lift, U is the jet velocity, is the lift coefficient obtained from experience, is the flow area, r is the particle radius, α is the pressure correction factor, is the fluid density.

5. The design optimization method for deep-sea mineral resource collection head based on Coanda effect according to claim 1 is characterized in that: The formula for determining the width of the deep sea mineral resource cluster head is as follows: ； Where W is the width of the deep-sea mineral resource cluster head, is the target collection yield, U is the jet velocity, is the volume concentration of ore particles, For abundance.

6. The design optimization method for deep-sea mineral resource collection head based on Coanda effect according to claim 1 is characterized in that: The formula for determining the jet flow rate of a deep-sea mineral resource cluster is as follows: ； in is the jet flow rate, To collect the target yield, For abundance, is the volume concentration of ore particles.

7. The design optimization method for deep-sea mineral resource collection head based on Coanda effect according to claim 1 is characterized in that: The formula for determining the jet width of the deep-sea mineral resource set head is as follows: ； Where U is the jet velocity, is the jet flow rate, and D is the jet orifice width.

8. The design optimization method for deep-sea mineral resource collection head based on Coanda effect according to claim 1 is characterized in that: The particle stripping shear force is calculated based on the sediment viscosity, and the height above the ground of the deep-sea mineral resource collection head is determined based on the relationship between the particle stripping shear force and the height above the ground.

9. The design optimization method for deep-sea mineral resource collection head based on Coanda effect according to claim 1 is characterized in that: The formula for determining the radius of curvature of the Coanda surface plate of the deep sea mineral resource set head is as follows: ； Where R is the radius of curvature of the Coanda surface plate, is the pressure difference on both sides of the Coanda surface plate, L is the flow field action length, is the fluid density and U is the jet velocity.

Images