CN106874539A - For the method and device of the filter disc flow passage structure design of laminated filter - Google Patents

Abstract

The invention relates to the technical field of agricultural water-saving irrigation equipment, in particular to a method and a device for designing a filter plate channel structure of a laminated filter. Wherein, the method mainly includes the following steps: establishing a first structural model of the flow channel between adjacent filter sheets, and performing numerical simulation calculation on the first structural model to determine the first flow channel parameters of the flow channel; according to the first flow channel parameters, preset Runner correction item; according to the flow channel correction item, the calculation domain boundary of the first structure model is iteratively corrected through the fractal algorithm to obtain the second structure model; the reliability verification of the second structure model is carried out. The device mainly includes a modeling unit, a correction unit and a verification unit. The method and the device can shorten the design and manufacture cycle and reduce the design cost, and the optimized design of the filter plate flow channel structure has a good filtering effect and effectively reduces the head loss caused by filtration; at the same time, the method and the device can also be reliable and low Expensively verify the validity of the structural design.

Description

Method and device for designing filter plate channel structure of laminated filter

technical field

The invention relates to the technical field of agricultural water-saving irrigation equipment, in particular to a method and a device for designing the filter plate channel structure of a laminated filter.

Background technique

Micro-irrigation is a more popular water-saving irrigation method at present, which greatly reduces agricultural water consumption, but this type of irrigation technology has strict requirements on water quality. If various impurities in irrigation water cannot be effectively removed, it will Seriously affect the quality of water, cause blockage of equipment at all levels, and seriously cause the paralysis and scrapping of the entire drip irrigation or micro irrigation system.

As far as my country's small and medium-sized agricultural irrigation is concerned, especially in the Hetao irrigation area where water from the Yellow River is used, the main impurities in the diversion water are a large amount of fine-grained sediment. Therefore, in the micro-irrigation irrigation system, the filtration efficiency of sediment becomes the key to the success of the irrigation system.

At present, the laminated filter is the preferred filter in the micro-irrigation irrigation system. Its core component is the laminated sheet. The upper and lower surfaces of the plastic laminated sheet of the laminated filter are engraved with a large number of longitudinal micro-grooves and laminated on the inner support. , compressed by spring and fluid pressure, the grooves between the laminates intersect to form a deep filter unit with a series of unique filter channels. When the laminated filter is working, the water flow enters the laminated filter from the outer ring of the filter element and flows out from the inner ring. The laminated sheets are compressed by springs and fluid pressure. The greater the pressure difference, the tighter the laminated sheets are pressed, forming a laminated sheet. Self-locking high-efficiency filtration.

At present, the research on the filtration efficiency of the laminated filter mainly focuses on the analysis of its automatic backwashing. Among them, the field test and the platform test have been widely used in the optimal design of the laminated filter because of their accuracy. Applications. However, for the design and processing of laminated filters, corresponding molds need to be made, and the design and manufacture cycle is very long, and the method of optimizing the flow channel structure of the filter discs in the filter by using experimental tests is not economical and reasonable.

Contents of the invention

(1) Technical problems to be solved

The technical problem to be solved by the present invention is to provide a method and device for the design of the filter flow channel structure of the laminated filter, which can shorten the design and manufacturing cycle, and the optimally designed filter flow channel structure has a good Filtration effect, effectively reducing the head loss caused by filtration.

(2) Technical solutions

In order to solve the above-mentioned technical problems, the present invention provides a method for designing the filter plate channel structure of a laminated filter, comprising the following steps:

Establishing a first structural model of the flow channel between adjacent filter sheets, and performing numerical simulation calculations on the first structural model to determine the first flow channel parameters of the flow channel;

Preset a runner correction item according to the first runner parameter;

According to the flow channel correction item, iteratively correcting the calculation domain boundary of the first structural model through a fractal algorithm to obtain a second structural model;

Reliability verification is performed on the second structural model.

Further, the establishment of the first structural model of the flow channel between the filters, and performing numerical simulation calculation on the first structural model to determine the first flow channel parameters of the flow channel, further includes:

constructing the first structural model by geometric modeling;

meshing the first structural model;

setting boundary conditions on the computational domain of the first structural model;

According to the boundary conditions, a numerical simulation calculation is performed on the meshed first structure model by using a computational fluid dynamics algorithm, so as to determine the first flow channel parameters of the flow channel.

Further, according to the boundary conditions, numerical simulation calculation is performed on the first structural model after grid division by computational fluid dynamics algorithm to determine the first flow channel parameters of the flow channel, further comprising:

Determining the first flow channel parameters of the flow channel includes a turbulence model, a pressure term, and a pressure-velocity coupling item of the fluid in the flow channel;

Computing said turbulence model by a steady semi-implicit uncoupled algorithm;

calculating said pressure term by a second order upwind scheme using a pressure solver;

The pressure-velocity coupling term is calculated by the SIMPLE algorithm.

Further, the preset flow path correction item according to the first flow path parameter further includes:

According to the first flow channel parameters, the filtering accuracy and the sediment concentration distribution parameters in the flow channel are preset.

Further, according to the flow path correction item, the calculation domain boundary of the first structural model is iteratively corrected by a fractal algorithm to obtain the second structural model, further comprising:

According to the flow channel correction item, iterative correction is performed on the calculation domain boundary of the first structural model by using the KOCH curve.

Further, according to the flow path correction item, using the KOCH curve to iteratively correct the calculation domain boundary of the first structural model further includes:

Determining the filtration accuracy in the flow channel includes the area of the inscribed circle of the flow channel section;

determining all corners of the computational domain boundary of the first structural model;

Keeping the area of the inscribed circle of the cross-section of the flow channel constant, using the KOCH curve to iteratively correct any one of the corners to three corners;

chamfering all the corrected corners to obtain the second structure model.

Further, the method of keeping the area of the inscribed circle of the cross section of the flow channel constant, and using the KOCH curve to iteratively correct any one of the corners to three corners further includes:

determining the triangular section of said corner;

According to the filtration accuracy in the flow channel, iteratively adding two triangular sharp corners at preset positions on the two waists of the corners, so that the corners are iteratively corrected to three corners;

According to the preset position, multiple calculations are performed to verify the flow cross section of the flow channel, so as to determine the best position of the sharp corner when the flow cross section of the flow channel is the largest.

Further, the reliability verification of the second structural model further includes:

performing numerical simulation calculations on the second structural model to determine the corrected second flow channel parameters of the flow channel;

comparing the first flow path parameters with the second flow path parameters;

Wherein, the second channel parameters include a corrected turbulence model, a pressure item and a pressure-velocity coupling item of the fluid in the channel.

Further, the reliability verification of the second structural model further includes:

performing a fluid dynamic simulation calculation on the second structural model to determine the corrected filtering parameters of the flow channel;

Comparing the filtering parameters and the flow channel correction item;

Wherein, the filtering parameters include the corrected filtering accuracy and sediment concentration distribution parameters in the flow channel.

The present invention also provides a device for designing the filter plate channel structure of the laminated filter, including:

a modeling unit, configured to establish a first structural model of the flow channel between the filter discs, and perform numerical simulation calculation on the first structural model to determine the first flow channel parameters of the flow channel;

The correction unit is configured to preset a flow path correction item according to the first flow path parameter, and to iteratively correct the calculation domain boundary of the first structural model through a fractal algorithm according to the flow path correction item, so as to obtain the second structural model;

A verification unit, configured to perform reliability verification on the second structural model.

(3) Beneficial effects

The above-mentioned technical solution of the present invention has the following beneficial effects: In the method and device for the filter flow channel structure design of the laminated filter of the present invention, the method mainly includes the following steps: establishing the first flow channel between adjacent filter plates The structural model is to carry out numerical simulation calculation on the first structural model to determine the first flow channel parameters of the flow channel; according to the first flow channel parameters, preset the flow channel correction items; Iterative correction of the computational domain boundaries to obtain the second structural model; reliability verification of the second structural model. The device mainly includes a modeling unit, a correction unit and a verification unit. The method and the device can shorten the design and manufacture cycle and reduce the design cost, and the optimized design of the filter plate flow channel structure has a good filtering effect and effectively reduces the head loss caused by filtration; at the same time, the method and the device can also be reliable and low Expensively verify the validity of the structural design.

Description of drawings

Fig. 1 is a schematic flow chart of the method of the embodiment of the present invention;

Fig. 2 is the module connection schematic diagram of the device of the embodiment of the present invention;

Fig. 3 is the structural sectional view of the first structural model of the experimental example of the present invention;

Fig. 4 is the structural sectional view of the second structure model of the embodiment of the present invention;

Fig. 5 is the cross-sectional velocity vector diagram of the first structural model of the embodiment of the present invention;

Fig. 6 is the cross-sectional velocity vector diagram of the second structural model of the embodiment of the present invention;

Fig. 7 is a pressure distribution diagram of the first structural model of the embodiment of the present invention;

Fig. 8 is a pressure distribution diagram of the second structural model of the embodiment of the present invention;

Figures 9a to 9j are the sediment content distribution diagrams of the second structural model of the embodiment of the present invention;

Wherein, FIG. 9a is a schematic diagram of a flow channel interception of the second structural model of the embodiment of the present invention;

Figure 9b is a cross-sectional sediment content distribution diagram of the target flow channel in Figure 9a;

Figure 9c is an enlarged schematic view of area A in Figure 9b;

Fig. 9d to Fig. 9j are cross-sectional sediment content distribution diagrams of the intercepted channel in Fig. 9a.

Among them, 100, modeling unit; 200, correction unit; 300, verification unit; 110, corner area; 111, sharp corner; 120, inscribed circle; 130, waistline; 140, target flow channel; 150, interception flow road.

detailed description

Embodiments of the present invention will be further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but should not be used to limit the scope of the present invention.

Embodiment one

The method and device used in the design of the filter flow channel structure of the laminated filter provided in the first embodiment can shorten the design and manufacturing cycle and reduce the design cost, and the optimally designed filter flow channel structure has a good filtering effect , effectively reducing the head loss caused by filtration; at the same time, the method and device can also verify the validity of the structural design reliably and with low consumption.

Specifically, as shown in FIG. 1 , the method includes at least four steps including step S1 , step S2 , step S3 and step S4 .

S1. Establish the first structural model of the flow channel between adjacent filter sheets, and perform numerical simulation calculation on the first structural model to determine the first flow channel parameters of the flow channel. Through the calculation of step S1, the pressure field, velocity field, etc. can be obtained Distribution parameters, to determine the flow characteristics, velocity distribution, pressure distribution and other factors affecting sediment settlement in the flow channel between the laminated filter sheets and the influence of the flow channel structure on the filtration efficiency.

Wherein, step S1 further includes the following steps:

S110. Construct the first structure model through geometric modeling. During modeling, PRO/E software is preferably used to realize the geometric modeling of the flow channel, and the size of the flow channel is measured using an electron microscope and a vernier caliper.

S120, performing grid division on the first structure model, preferably adopting GAMBIT to perform grid division on the entire model, GAMBIT is a software package designed to help analysts and designers establish and grid computational fluid dynamics (CFD) models , the grid is preferably a 0.04mm tetrahedral grid, and a certain grid density is set at the boundary of the near-wall region.

S130. Set boundary conditions for the calculation domain of the first structural model, preferably set the boundary conditions of the water flow inlet and outlet of the flow channel as flow velocity inlet and free flow respectively.

S140. According to the boundary conditions, perform numerical simulation calculation on the first structural model after grid division by computational fluid dynamics algorithm, so as to determine the first flow channel parameters of the flow channel; preferably, use FLUENT software to perform computational fluid dynamics algorithm The first structure model after grid division is used for numerical simulation calculation. FLUENT software is a CFD software package, which can be used in industrial fields related to fluid, heat transfer and chemical reaction.

In step S140, for the convenience of calculation, the following steps are further included:

S141. Determine the first flow channel parameters of the flow channel, including but not limited to the turbulence model, pressure item and pressure-velocity coupling item of the fluid in the flow channel.

S142. Calculate the turbulence model through a steady semi-implicit uncoupling algorithm. The preferred turbulence model is the Realizablek-ε model, which is one of the preset turbulence models in the FLUENT software; in the adopted semi-implicit uncoupling algorithm, the fluid All parameters are constants.

S143 , using a pressure solver to calculate a pressure item through a second-order upwind scheme, where the pressure solver refers to a pressure-based solver.

S144. Calculate the pressure-velocity coupling item through the SIMPLE algorithm, wherein, according to the pressure item, the preset flow rate of the pressure item is calculated by measuring the size of the flow channel; the SIMPLE algorithm is a numerical algorithm that can calculate the flow of any flow rate, the The algorithm is applied to the calculation of compressible flow field and incompressible flow field.

In the above-mentioned step S140, based on CFD technology simulation calculation, simulation results such as flow velocity distribution cloud map, pressure distribution cloud map, and turbulent kinetic energy intensity distribution cloud map can be obtained, as shown in FIG. , the velocity distribution of the entire runner section is as follows: the velocity at the center of the runner section is the largest, and the velocity becomes smaller as it goes to the surroundings, especially in each corner area 110, which can form a relatively large low-velocity zone; observing the pressure distribution of the overall runner, it can be It can be seen that the pressure value shows a uniform downward trend from the water inlet to the water outlet. The cross-sectional flow velocity near the outlet is obviously higher than that near the inlet, and its turbulent intensity is stronger. Through the analysis of the parameters of the first flow channel above, it can be seen that the sand settlement effect in the low-velocity zone is better but the relative area is smaller.

S2. According to the first flow channel parameters, preset flow channel correction items, wherein the flow channel correction items include but not limited to the filtration accuracy and sediment concentration distribution parameters in the flow channel. In this embodiment, each corner of the flow channel section The area of the inscribed circle 120 represents the filtering accuracy.

Therefore, in step S2, further include:

S210. According to the parameters of the first flow channel, preset the filtering precision and the sediment concentration distribution parameters in the flow channel.

S3. According to the flow channel correction item, the calculation domain boundary of the first structural model is iteratively corrected by the fractal algorithm to obtain the second structural model. By changing the boundary shape of the flow channel in the first structural model, the fractal algorithm is used to increase the flow channel The cross-sectional area of the flow channel is used to enhance the efficiency of water flow and reduce the head loss in the flow field. At the same time, the low-velocity area of the flow channel section is increased, which increases the possibility of sediment settlement and effectively enhances the stability of sediment settlement. efficiency.

Specifically, taking the current common triangular flow channel as an example, according to the flow channel correction item, the calculation domain boundary of the first structural model is iteratively corrected using the KOCH curve.

Wherein, step S3 further includes:

S310. Determining the filtration accuracy in the flow channel includes the area of the inscribed circle 120 in the cross section of the flow channel;

S320. Determine all corners of the calculation domain boundary of the first structural model;

S330 , keep the area of the inscribed circle 120 of the flow channel section constant, and use the KOCH curve to iteratively correct any corner to three corners.

In other words, any corner of the flow channel is regarded as a triangle, and it is corrected. The fractal algorithm is introduced in the correction, and the KOCH curve is used to iterate the boundary of the calculation domain. The iterative method is preferably: the KOCH curve is directly applied to the triangle On the two sides of the corner, the number of completely sharp corner 111 areas on the corner is increased from one to three, and the radius of the inscribed circle 120 of the flow channel section is kept constant to ensure the original filtration accuracy when making improvements. The increase of the sharp angle 111 increases the area of the cross-section, thereby increasing the low-velocity sand settlement area, increasing the cross-sectional area of the flow channel, and reducing the head loss.

Specifically, in step S330, the following steps are further included:

S331. Determine the triangular section of the corner;

S332. According to the filtration accuracy in the flow channel, iteratively add two triangular sharp corners 111 at preset positions on the two waists of the corners, so that the corners are iteratively corrected to three corners; wherein, the corners on the two waists of the corners The preset position of each corner is any one of the four quarter nodes on the waistline 130 of the corner, that is, the preset position of the sharp corner 111 is: 1/3 of the two waistlines 130 of the corner, One or a combination of 1/2 and 2/3.

S333 , according to the selected preset position of the sharp angle 111 , iteratively calculate and verify the flow cross section of the flow channel several times, so as to determine the best position of the sharp angle 111 when the flow cross section of the flow channel is the largest.

S340, chamfering all the corrected corners to obtain the second structure model, preferably rounding each corner, by rounding the sharp corners 111 of the original section, avoiding the sharpness of the flow channel Corner 111 is easy to accumulate a large amount of sediment, it is not easy to clean, and after a long period of accumulation, it will cause the problem of clogging or even scrapping of the filter, which can effectively improve the efficiency of backwashing, and at the same time can bring convenience to manufacturing and reduce manufacturing costs .

S4. Perform reliability verification on the second structure model. The reliability verification described in the embodiment of the present invention includes but not limited to flow channel parameter comparison verification and flow channel filtering effect verification.

Among them, the comparative verification of flow channel parameters is to determine the improvement of the filter performance of the filter by comparing the parameters of the flow field in the flow channel before and after optimization, measure the pressure loss of the filter, and verify the fact that it reduces the head loss.

The comparative verification of runner parameters mainly includes the following steps:

S411. Perform numerical simulation calculation on the second structural model to determine the corrected second flow channel parameters of the flow channel, wherein the second flow channel parameters include the corrected turbulence model and pressure item of the fluid in the flow channel and the pressure-velocity coupling term.

Specifically, by repeatedly modifying the relevant parameters in the second structural model, such as the preset position of the sharp corner 111, and repeatedly performing numerical simulation calculations on the second structural model, the most optimal second structural model is determined. According to the most optimal second The structural model determines second runner parameters of the revised runner.

Among them, the determination of the most preferred second structural model is based on the measurement of the filter discs of the optimized laminated filter under different flow conditions, and the corresponding data are obtained, specifically:

The boundary conditions are preset during the measurement. The inlet of the flow channel is the boundary condition of the flow velocity inlet, and the outlet of the flow channel is the boundary condition of the free flow. The size of the cross-sectional area is calculated, and the boundary condition of the outlet of the flow channel cannot be measured because it is located inside the filter, so it is set as free flow

S412. Comparing the parameters of the first flow channel with the parameters of the second flow channel, such as comparing the turbulence model, pressure item and pressure-velocity coupling item in the flow channel before and after optimization, the calculation results are all relative values, by comparing the flow field in the flow channel before and after optimization Parameters to determine the improvement of the filter performance of the filter, by measuring the pressure loss of the filter, confirming the fact that it reduces the head loss.

The verification of the filter effect of the flow channel mainly includes the following steps:

S421. Perform a fluid dynamic simulation calculation on the second structure model to determine a filter parameter of the corrected flow channel; wherein the filter parameter includes a filter accuracy and a sediment concentration distribution parameter in the corrected flow channel.

S422. Comparing the filtering parameter and the flow path correction item.

Preferably, the two-phase flow simulation algorithm is used to calculate the fluid flow in the flow channel of the second structure model, and the Euler-Euler model is used for the calculation of the mixed flow of water and sand, so as to verify the sediment distribution in the designed product and to verify that the sediment An increase in the level of subsidence.

Specifically, according to the Euler equation of the filter sheet of the optimized laminated filter under the simulation algorithm of the sediment two-phase flow, the distribution of the sediment in the flow channel is simulated and calculated. Among them, the Realizable k-ε model of the turbulent flow model is also selected. The calculation method adopts a semi-implicit non-coupling algorithm with constant parameters. Algorithmic calculations. In the setting of the Euler model, set the solid phase particles as sand, and set the corresponding density, particle concentration distribution and other values. The calculation result is obtained, and the calculation result is compared with the preset flow channel correction item, and whether the second model structure has achieved the expected effect is judged according to the distribution of sediment concentration.

The method described in the embodiment of the present invention is applicable to the optimal design of the filter structure in various types of laminated filters, and the filtering performance of the optimized filter is greatly improved. Due to the change of the shape of the flow channel, the optimized filter flow channel structure increases the cross-sectional area, which can reduce the head loss during the filtration process. At the same time, the increased sharp angle 111 provides more sediment settlement for filtration. area, which enhances the filtering effect, and the sharp corners 111 designed with rounded corners are conducive to backwashing and are easier to manufacture, which greatly reduces the hidden danger of flow channel blockage, allowing it to run for a long time, reducing the number of backwashing times and The previous high efficiency can be maintained after backwashing.

It can be seen from the above that this method makes full use of the advantages of CFD visualization calculation, which greatly reduces the design cost, shortens the development cycle and improves the independent development ability; The theoretical shortcomings of sheet filter design have significant significance and broad prospects.

Embodiment two

Based on the method described in Embodiment 1, this Embodiment 2 provides a device for the design of the filter plate channel structure of the laminated filter, and the method as described in Embodiment 1 can be well implemented by using this device. In this way, the flow channel structure formed by the filter discs of the laminated filter can be reliably optimized, the design and manufacturing cycle can be shortened, and the design cost can be reduced. head loss; at the same time, the method and device can also verify the validity of the structural design reliably and with low consumption.

As shown in Figure 2, the device mainly includes a modeling unit 100, a correction unit 200, and a verification unit 3003, wherein the modeling unit 100 is used to establish a first structural model of the flow channel between filters, and numerically perform a numerical analysis on the first structural model. Simulation calculation to determine the first flow channel parameter of the flow channel; the correction unit 200 is used to preset the flow channel correction item according to the first flow channel parameter, and to calculate the calculation domain boundary of the first structural model through the fractal algorithm according to the flow channel correction item Iterative correction is performed to obtain the second structural model; the verification unit 3003 is configured to verify the reliability of the second structural model.

The specific structure and principle of the method of Example 1 and the device of Example 2 will be further described in detail below through an experimental example.

Experimental example

The method involved in this experimental example is as described in Example 1, and the experimental device used is as described in Example 2. The method and device for optimizing the flow channel structure will be described in detail below by taking the structure of the flow channel between two adjacent filter discs of the agricultural laminated filter as an example.

1. Establish a first structural model of the flow channel between adjacent filter sheets through the modeling unit 100, and perform numerical simulation calculation on the first structural model to determine the first flow channel parameters of the flow channel.

As shown in Figure 3, PRO/E software is used to realize the geometric modeling of the flow channel. The cross-sectional shape of the flow channel is a triangle with a total of three corners. The size of the flow channel includes: the diameter of the inscribed circle 120 of the flow channel section is 217.32mm , the cross-sectional area of flow is 0.0614mm ² ; use GAMBIT software to mesh the first structure model, the mesh adopts tetrahedral mesh with a scale of 0.04mm, and the inlet and outlet of the flow channel and the near wall area of the calculation domain Set mesh refinement at the boundary. The boundary condition of the inlet is set to flow velocity inlet, the boundary condition of the outlet is set to free flow, and the flow velocity at the inlet is calculated by the flow through the filter.

2. According to the boundary conditions, use the modeling unit 100 to perform numerical simulation calculation on the meshed first structure model through computational fluid dynamics algorithm, so as to determine the first flow channel parameters of the flow channel.

In the experiment, the flow of fluid in the channel between two adjacent filters can be regarded as a typical viscous flow, which is incompressible and satisfies the continuity equation and momentum conservation equation of fluid motion; The water flow movement is simulated. The selected turbulence model is the Realizable k-ε model corrected by low Reynolds number. The calculation method adopts a semi-implicit non-coupling algorithm with constant parameters, and the pressure item is calculated by a second-order upwind algorithm using a pressure-based solver. Therefore, the pressure-velocity coupling term is calculated using the SIMPLE algorithm.

3. Determine the first flow channel parameters of the flow channel through the modeling unit 100, specifically: calculate the velocity, pressure distribution and other parameters of the flow field of the first structural model, determine the sediment settlement area, the determinant factors of the sediment settlement amount, and the flow The effect of channel boundary structure on filtration efficiency and clogging problems.

As shown in Figure 5 and Figure 7, based on the simulation calculation results of CFD software, the schematic diagrams of parameters such as flow velocity distribution cloud map and pressure distribution cloud map are obtained. The range of parameters such as values.

It can be seen from Fig. 5 that the flow velocity distribution in the flow field has a strong regularity, the area with high velocity (the light-colored area in the center of the section in the figure, denoted as area I) and the area with small velocity (the velocity near the wall shows are dark areas, denoted as area II, area III, and area IV). Diffusion from the center to the outside, the flow velocity is gradually reduced, the flow velocity in the middle mainstream area is higher, such as area I, mainly due to water passing, taking into account the mixing of water flow; the flow velocity in the near wall area is the smallest, such as area II, area III and area Ⅳ, which is conducive to the settlement of sand particles, forms a low-velocity area, and has poor scouring effect, so that sand particles can settle in large quantities. It is the main utilization area of filtration, and it should be paid attention to and its area should be increased as much as possible, especially the area Ⅳ in Figure 5. The flow velocity in this area is small and the area is relatively large, which strengthens the effect of sediment settlement, and should be strengthened to the maximum in the optimization design.

4. According to the first flow channel parameter, input the preset flow channel correction item to the correction unit 200, and according to the flow channel correction item, use the correction unit 200 to iteratively correct the calculation domain boundary of the first structural model through the fractal algorithm, so as to obtain the second The second structure model is used to correct and analyze the flow channel of the second structure model.

According to the above analysis, in order to improve the filtration performance of the laminated filter, the low flow area near the wall should be increased as much as possible, and the filtration accuracy of the filter should be ensured at the same time: the corners with low flow velocity should be reserved and strengthened, so that The sediment settlement area is further increased, and under the premise of ensuring the filtration accuracy (that is, ensuring that the diameter of the inscribed circle 120 of the flow section remains unchanged), the area of the flow section is increased as much as possible, and the flow rate at the same flow rate is increased. , to reduce head loss during filtration.

In view of the advantages of sand settling in the low flow velocity area of the corner, the flow channel structure is optimized:

As shown in Fig. 4, firstly, the triangle of the flow channel of the first structure model is corrected, the fractal algorithm is introduced, and the Koch curve is used to iteratively correct the flow channel section, and the Koch curve is directly applied to the two waistlines 130 of the triangle, and the The number of complete sharp corners 111 is increased from one to three, and the radius of the inscribed circle 120 of the flow channel section remains unchanged during correction to ensure the original filtration accuracy; due to the increase of sharp corners 111, the area of the cross section increases, Thereby increasing the low-velocity sand settlement area, increasing the cross-sectional area of the flow channel, and reducing the head loss.

Among them, the preset position of the sharp corner 111 can be set at the midpoint, one-third or two-thirds of the triangular waistline 130 of the flow channel section, considering the effective expansion of the flow channel cross-sectional area and increasing the low-speed According to the processing results under different data, it is preferable to set the sharp corner 111 at the midpoint of the waistline 130 as the best position of the sharp corner 111 .

Then, the original corners and the newly added sharp corners 111 are rounded respectively, preferably using a circular arc with a size of 0.1 mm for rounding. After rounding, the sharp corners 111 can be effectively avoided. The disadvantage of depositing sand and sand is not easy to clean, so the efficiency of backwashing can be improved, and it can also bring convenience to manufacturing.

As shown in Figure 4, the diameter of the runner section of the second structural model shown in Figure 4 remains unchanged at 217.32mm. In the fractal algorithm, the preset position of the sharp corner 111 is set at the optimal position, that is, the two waists of the triangular section At one-half of the line 130, it can be seen from FIG. 4 that the flow channel has three sharp corners 111 at this time, and the area of the flow cross section is 0.0656 mm.

5. Using the verification unit 300 to perform reliability verification on the second structural model, the reliability verification includes but not limited to flow channel parameter comparison verification and flow channel filtering effect verification, and analyzes the performance of the optimized flow channel.

Among them, the analysis results of the comparative verification of the flow channel parameters are as follows:

Comparing Figure 3 and Figure 4, and Figure 5 and Figure 6, it can be seen that compared with the optimized second structural model before optimization, the area of the optimized flow channel flow section increases , and at the same time ensure that the filtering accuracy remains unchanged, at the same time, the cross-sectional area of the corner area 110 of the second structural model is more than twice the cross-sectional area of the corner area 110 of the first structural model before optimization, Ensuring the expansion of the effective sedimentation zone.

Comparing Figure 7 and Figure 8, it can be seen that after correction, the pressure drop in the entire flow channel area of the second structure model is significantly reduced, and there is no obvious change in the uniformity of pressure drop, but the starting and ending pressure There is a significant decrease in the difference, which means that the head loss in the whole flow process is significantly reduced.

The analysis results of the verification of the flow channel filtration effect are as follows:

By using the two-phase flow simulation algorithm to calculate the fluid flow in the flow channel of the second structure model, the Euler-Eulerian model is used for the calculation of the mixed flow of water and sand, so as to verify the sediment distribution in the designed product to confirm the sediment settlement level improvement.

Based on the simulation of sediment concentration distribution, the SIMPLE algorithm is used to solve the discrete governing equations. The calculation method of each solution variable adopts the second ^- order upwind algorithm. The particle size of the phase is uniform, and the shape is spherical, with a diameter of 0.05mm (the diameter of the solid phase particle can be adjusted and changed according to the applicable situation); then set the concentration distribution of the solid phase particle, set the concentration to 0.2%, and perform simulation calculations .

Figures 9a to 9j are the distribution diagrams of the sediment content of the second structural model of the embodiment of the present invention. According to the distribution of sediment in the cross-section of the optimized flow channel, due to the linear decrease of the flow cross-sectional area from the water inlet to the outlet Small, resulting in an increase in the flow velocity per unit area; while the center of the flow channel belongs to the mainstream area, the flow velocity is larger than that near the wall.

Set the sediment concentration entering the flow channel to 0.2%. In the calculation results of the two-phase flow simulation algorithm, the volume concentration distribution of the sediment phase ranges from 0 to 0.26%. According to the cross-sectional sediment distribution in Figure 9a to Figure 9j, it can be seen that The volume ratio of the outflow sediment phase is not evenly distributed in the entire cross-section, and the sediment concentration in the mainstream area is smaller than that in the corner area 110; according to Figures 9a to 9j, it can be pointed out that the sediment concentration distribution in a single channel is relatively stable, and the movement process When encountering the overlapping process of the upper and lower flow channels, the greater the proportion of the overlapping section, the higher the concentration of the sediment particle phase in the flow channel. Among them, the overlapping section refers to the part where the bottom edges of the upper and lower adjacent flow channels overlap; Similarly, with the decrease of the proportion of the coincidence section, the concentration of the sediment particle phase also decreases correspondingly; when the concentration of the sediment particle phase is high, the low-velocity zone at the corner near the wall creates a good environment for the settlement of the sediment particle phase. conditions of.

Specifically, as shown in Figures 9a to 9j, the center of the target flow channel is selected, and the cross-sections of seven intercepted flow channels 150 interlaced with any intercepted flow channels of two adjacent filter sheets are selected. The volume concentration ratio of the upper sediment particle phase was used to analyze the distribution law of the sediment phase concentration before, during and after staggering.

When the sediment concentration at the entrance is 0.2%, the volume concentration distribution diagrams of the sediment phase in the seven sections intercepted in Fig. 9a to Fig. 9j are respectively intercepted. In Fig. 9a, there are seven sections a ~ g intercepted The cross-sectional schematic diagram of the flow channel 150, the intercepted cross-sections a to g of the seven intercepted flow channels 150 in the figure correspond to those shown in Figure 9d to Figure 9j respectively; the flow channel below the intercepted flow channel 150 in Figure 9a is defined as the target flow Road 140, as shown in Figure 9b and Figure 9c; the color gradient contrast legend given in Figure 9a is the legend corresponding to each area label in Figure 9b to Figure 9j, and the legend includes a total of 11 color scales for comparison Use, respectively, scales 1 to 11.

It can be seen from observation that in the cross-sectional sediment concentration distribution diagrams of the intercepted flow channel 150 shown in Fig. 9d ~ Fig. 9j, the upper flow path in Fig. 9d and Fig. 9e is the same flow path, called the first flow path; Fig. 9f ~ Figure 9i is the same flow channel, called the second flow channel; Figure 9j is the third flow channel. Among them, because the data shown in the second flow channel is relatively comprehensive, the second flow channel is taken as an example. Before the target flow channel 140 coincides with the second flow channel, the sediment concentration at the sharp corner 111 far away from the second flow channel is relatively high, and this feature has been maintained until the rear end of the flow channel, indicating that when it is combined with another lamination During the superimposition process of the groove flow channel, the turbulence caused by the water flow in the external flow channel to its own flow channel will cause the sediment particles to move in the opposite direction and shift to the fractal sharp corner 111 on the trapezoidal waist, which can effectively increase the Filtration capacity of laminated filter.

With the movement of the water flow, more and more overlapping parts of the target flow channel 140 and the second flow channel, according to the legend comparison in Fig. Scale 9, that is, increased from 0.18% to 0.32%; with more and more overlapping parts, the sediment phase concentration is also increasing. It shows that the volume concentration of the sediment particle phase in a single flow channel is relatively stable, but when the water flow in the flow channel encounters other overlapping flow channels, the concentration of the sediment particle phase will change, and the more the overlap, the higher the concentration; when the water flow When the movement continues, the overlapping section will become less and less, and the sediment phase concentration will decrease accordingly.

From the above reliability verification, it can be seen that the sediment at the sharp corner 111 created after optimization does have obvious accumulation, and the degree of sediment accumulation is significantly improved compared with the flow channel before optimization, achieving enhanced sediment settlement. performance requirements.

To sum up, in the method and device for designing the flow channel structure of a laminated filter in this embodiment, the method mainly includes the following steps: establishing the first structure model of the flow channel between adjacent filter plates, and the first structure The model performs numerical simulation calculations to determine the first flow channel parameters of the flow channel; according to the first flow channel parameters, the flow channel correction item is preset; according to the flow channel correction item, the calculation domain boundary of the first structural model is iteratively corrected by the fractal algorithm , to obtain the second structural model; conduct reliability verification on the second structural model. The device mainly includes a modeling unit 100 , a correction unit 200 and a verification unit 3003 . The method and the device can shorten the design and manufacture cycle and reduce the design cost, and the optimized design of the filter plate flow channel structure has a good filtering effect and effectively reduces the head loss caused by filtration; at the same time, the method and the device can also be reliable and low Expensively verify the validity of the structural design.

Those of ordinary skill in the art can understand that all or part of the steps of the method provided by the method embodiments related to Fig. 1 can be completed by program instruction related hardware, and the aforementioned program can be stored in a computer-readable storage medium When the program is executed, it executes the steps of the above-mentioned method embodiments; and the aforementioned storage medium includes: ROM, RAM, magnetic disk or optical disk and other various media that can store program codes.

Through the above description of the implementations, those skilled in the art can clearly understand that each implementation can be implemented by means of software plus a necessary general-purpose hardware platform, and of course also by hardware. Based on this understanding, the essence of the above technical solution or the part that contributes to the prior art can be embodied in the form of software products, and the computer software products can be stored in computer-readable storage media, such as ROM/RAM, magnetic discs, optical discs, etc., including several instructions to make a computer device (which may be a personal computer, server, or network device, etc.) execute the methods described in various embodiments or some parts of the embodiments.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the embodiments of the present invention, not to limit them; although the embodiments of the present invention have been described in detail with reference to the foregoing embodiments, those skilled in the art The skilled person should understand that: it is still possible to modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the present invention The scope of the technical solution of each embodiment of the embodiment.

Claims (10)

1. A method for the design of the filter disc flow passage structure of the laminated filter, is characterized in that, comprises the following steps: Establishing a first structural model of the flow channel between adjacent filter sheets, and performing numerical simulation calculations on the first structural model to determine the first flow channel parameters of the flow channel; Preset a runner correction item according to the first runner parameter; According to the flow channel correction item, iteratively correcting the calculation domain boundary of the first structural model through a fractal algorithm to obtain a second structural model; Reliability verification is performed on the second structural model. 2. The method according to claim 1, characterized in that, the first structural model of the flow channel between the filters is established, and numerical simulation calculation is performed on the first structural model to determine the first structural model of the flow channel. A channel parameter, further including: constructing the first structural model by geometric modeling; meshing the first structural model; setting boundary conditions on the computational domain of the first structural model; According to the boundary conditions, a numerical simulation calculation is performed on the meshed first structure model by using a computational fluid dynamics algorithm, so as to determine the first flow channel parameters of the flow channel. 3. The method according to claim 2, characterized in that, according to the boundary conditions, the computational fluid dynamics algorithm is used to perform numerical simulation calculations on the first structural model after grid division, so as to determine the flow path First runner parameters, further including: Determining the first flow channel parameters of the flow channel includes a turbulence model, a pressure term, and a pressure-velocity coupling item of the fluid in the flow channel; Computing said turbulence model by a steady semi-implicit uncoupled algorithm; calculating said pressure term by a second order upwind scheme using a pressure solver; The pressure-velocity coupling term is calculated by the SIMPLE algorithm. 4. The method according to claim 1, wherein the preset flow path correction item according to the first flow path parameter further comprises: According to the first flow channel parameters, the filtering accuracy and the sediment concentration distribution parameters in the flow channel are preset. 5. The method according to claim 4, characterized in that, according to the flow path correction item, the calculation domain boundary of the first structural model is iteratively corrected by a fractal algorithm to obtain the second structural model, further include: According to the flow channel correction item, iterative correction is performed on the calculation domain boundary of the first structural model by using the KOCH curve. 6. The method according to claim 4, wherein, according to the flow path correction item, using the KOCH curve to iteratively correct the calculation domain boundary of the first structural model, further comprising: Determining the filtration accuracy in the flow channel includes the area of the inscribed circle of the flow channel section; determining all corners of the computational domain boundary of the first structural model; Keeping the area of the inscribed circle of the cross-section of the flow channel constant, using the KOCH curve to iteratively correct any one of the corners to three corners; chamfering all the corrected corners to obtain the second structure model. 7. The method according to claim 6, wherein the area of the inscribed circle of the cross-section of the flow channel is kept constant, and any one of the corners is iteratively corrected to three corners by using the KOCH curve, further comprising: determining the triangular section of said corner; According to the filtration accuracy in the flow channel, iteratively adding two triangular sharp corners at preset positions on the two waists of the corners, so that the corners are iteratively corrected to three corners; According to the preset position, multiple calculations are performed to verify the flow cross section of the flow channel, so as to determine the best position of the sharp corner when the flow cross section of the flow channel is the largest. 8. The method according to claim 1, wherein the reliability verification of the second structural model further comprises: performing numerical simulation calculations on the second structural model to determine the corrected second flow channel parameters of the flow channel; comparing the first flow path parameters with the second flow path parameters; Wherein, the second channel parameters include a corrected turbulence model, a pressure item and a pressure-velocity coupling item of the fluid in the channel. 9. The method according to claim 1, wherein the reliability verification of the second structural model further comprises: performing a fluid dynamic simulation calculation on the second structural model to determine the corrected filtering parameters of the flow channel; Comparing the filtering parameters and the flow channel correction item; Wherein, the filtering parameters include the corrected filtering accuracy and sediment concentration distribution parameters in the flow channel. 10. A device for the design of the filter plate channel structure of the laminated filter, characterized in that it comprises: a modeling unit, configured to establish a first structural model of the flow channel between the filter discs, and perform numerical simulation calculation on the first structural model to determine the first flow channel parameters of the flow channel; The correction unit is configured to preset a flow path correction item according to the first flow path parameter, and to iteratively correct the calculation domain boundary of the first structural model through a fractal algorithm according to the flow path correction item, so as to obtain the second structural model; A verification unit, configured to perform reliability verification on the second structure model.