Micro-spraying hose optimization design method based on genetic algorithm

Abstract

The invention relates to a micro-spraying hose optimization design method based on a genetic algorithm, and the method comprises the steps: micro-spraying hose longitudinal hole array optimization parameter determination: according to the parameter requirements of a micro-spraying hose, a plurality of groups of micro-spraying hose longitudinal hole array optimization parameters are determined by applying the genetic algorithm, and the optimization parameters comprise the diameter of a spraying hole, the number of holes in the group, the interval value of the group holes and the interval value of the spraying hole; determining an edge distance range of edge holes in a single side of the micro-spraying belt, and for any group of longitudinal hole array optimization parameters of the micro-spraying belt, applying a genetic algorithm to obtain a group of hole position optimal parameters of spraying holes of the micro-spraying belt corresponding to the longitudinal hole array optimization parameters of the micro-spraying belt; the optimal parameters comprise the edge distance of each spray hole, a group hole pitch fine-tuning value and a spray hole pitch fine-tuning value; a plurality of micro-spraying hose optimization design schemes are obtained; and actual spraying widths corresponding to the multiple micro-spraying belt design schemes are obtained, and the optimal design scheme is determined according to the actual spraying widths and the micro-spraying belt spraying widths.

Description

Technical Field

[0001] The invention relates to the technical field of micro-spraying tapes, and in particular to a micro-spraying tape optimization design method based on a genetic algorithm. Background Art

[0002] As a new water-saving irrigation equipment, micro-sprinkler belt has the advantages of easy installation, strong anti-blocking ability and low investment cost. Spray irrigation is achieved by arranging small holes with a certain spacing and arrangement on the plastic hose. At present, micro-sprinkler belt can realize water and fertilizer integration, and has been gradually extended from the application of cash crops such as vegetables, fruit trees, and green land to field crops such as wheat, corn, and potatoes.

[0003] Micro-sprinkler belts use spray holes to deliver the water needed by crops to the roots of crops at a small flow rate. In order to ensure the uniformity of irrigation, high requirements are placed on the difference in the flow rate of the spray holes along the way and the uniformity of spraying on both sides. The combination of the diameter of the spray holes and the arrangement of the holes play a significant role in the hydraulic performance of the micro-sprinkler belt. In the past, the optimization design of the spray holes of micro-sprinkler belts basically followed the cyclic research and development path of empirical selection combination-processing test-parameter correction-processing test. This optimization design method is cumbersome, time-consuming and labor-intensive. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a micro-spray belt optimization design method based on genetic algorithm.

[0005] To solve the above problems, the technical solution adopted by the present invention is: A method for optimizing the design of micro-spraying belts based on a genetic algorithm, the method comprising: Step 1: Determine the optimization parameters of the longitudinal hole array of the micro-spray belt: For a micro-spray belt with a length of 100m, according to the parameter requirements of the micro-spray belt, the diameter of the spray holes, the number of holes in a group of holes, the spacing between groups of holes, and the spacing between spray holes set along the longitudinal direction of the micro-spray belt are used as parameter variables to be optimized, and the pressure drop percentage of the target micro-spray belt is less than 20% as the optimization target, and the genetic algorithm is used to determine the optimization parameters of multiple groups of longitudinal hole arrays of micro-spray belts; the parameter requirements of the micro-spray belt include: spray width of the micro-spray belt, diameter of the micro-spray belt, working pressure, flow rate per 100 meters, and aperture range; Step 2: Determine the optimal parameters of the micro-spray belt nozzle position Determine the margin range of the single-side side holes of the micro-spray belt, optimize the parameters of any group of longitudinal hole arrays of the micro-spray belt, apply the genetic algorithm, take the single-side Christian uniformity of 80% as the optimization target, fine-tune the group hole spacing value according to the parameters and the margin range of the side holes, optimize the margin of each nozzle hole, and thus obtain a corresponding group of optimal parameters for the nozzle hole positions of the micro-spray belt; the optimal parameters include: the margin of each nozzle hole, the fine-tuning value of the group hole spacing, and the fine-tuning value of the nozzle hole spacing; Step 3: Determine the optimal design of the micro-spray belt: The nozzle diameter and the number of holes in the group of holes in the optimal parameters of the longitudinal hole array in step 1, and the fine-tuning value of the group hole spacing and the nozzle spacing fine-tuning value corresponding to the optimal parameters of the group of longitudinal hole array in step 2, and the margin of the side holes are used as a micro-spray belt optimization design scheme to obtain multiple micro-spray belt optimization design schemes; The actual spray widths corresponding to the multiple micro-spray belt design schemes are obtained, and the optimal design scheme is determined according to the actual spray widths and the spray widths of the micro-spray belts.

[0006] As an embodiment of the invention, step one includes: Step S101: after determining the range of nozzle diameter, the range of the number of holes in a group of holes, the range of the distance between groups of holes, and the range of the distance between nozzles, a longitudinal hole array group is randomly generated. ， Each individual in the longitudinal hole array arrangement group represents a combination of a nozzle diameter, a number of holes in a group of holes, a group hole spacing value, and a nozzle hole spacing value; wherein the nozzle diameter range is obtained from the hole diameter range, and the number of holes in a group of holes, the group hole spacing value range, and the nozzle hole spacing value range are all determined by the designer according to needs; Step S102, taking the pressure drop percentage of the target micro-spray belt less than 20% as the optimization target, applying a genetic algorithm to perform selection, crossover, and mutation operations on the longitudinal hole array arrangement group, so that the group continues to evolve, and finally determining a plurality of optimized individuals, and using the combination method corresponding to each of the optimized individuals as a set of optimization parameters for the longitudinal hole array of the micro-spray belt.

[0007] As an embodiment of the invention, the range of the group hole spacing value is 2-15 cm, the range of the nozzle hole spacing value is 2-6 cm, and the range of the number of holes in the group hole is an odd number of 3-15.

[0008] As an implementation mode of the invention, step S102 includes: (1) Determine the total flow range, population size, maximum genetic generation, generation gap value, crossover rate, and mutation rate according to design requirements; (2) Setting the end pressure P of the micro-spray belt N , calculate each individual from the end of the micro-spray belt upstream section by section, and obtain the head end pressure P1 and total flow Q1 corresponding to each individual; the end pressure P N Obtained from the working pressure; (3) According to the head end pressure P1, the fitness of each individual is calculated using the following formula: ; (4) Check whether the total flow rate Q1 of each individual is within the range of the total flow rate. If it is not within the range of the total flow rate, the fitness of the individual is set to a negative value; the range of the total flow rate is determined by the flow rate per 100 meters; (5) Sort the individuals from high to low according to their fitness, and select and retain the best individuals according to the generation gap value; then reorganize the new individuals through crossover and mutation operations, and evaluate the fitness of the new individuals according to steps (2)-(4) until the population size is reached; (6) If the maximum genetic generation is not exceeded, step (5) is repeated for the new population to allow the population to evolve continuously, and eventually an excellent population with a small pressure drop ratio along the process is obtained. Individuals with a fitness value greater than 0.8 are selected as optimized individuals and used as the basic excellent solution for the optimization calculation of the nozzle hole position in step 2.

[0009] As an embodiment of the invention, step (2) includes: A. For any individual, calculate the orifice pressure P at each nozzle section by section from the end of the micro-spray belt to the upstream according to the following formula: i and orifice flow rate q i Obtaining the head end pressure P1; ; ; Among them, P i is the current nozzle pressure of hole i; P i-1 is the node pressure of nozzle i-1; d i is the nozzle diameter; i , S i and D are the resistance coefficient along the way, the distance between adjacent spray holes and the water filling diameter of the micro-spray belt, respectively; q i is the node flow rate of nozzle i; Along-the-line resistance coefficient λ i Calculated according to the following formula: Laminar flow area: ; Smooth area: ; Turbulent transition zone: ; Where Re is the Reynolds number; B. Use the following formula to get the total flow Q1: ; Among them, Q i Q is the flow rate of the micro-spray main pipe between nozzle i and nozzle i-1; i-1 The flow rate of the micro-spray main pipe between nozzle i-1 and nozzle i-2; q i-1 is the node flow rate of nozzle i-1.

[0010] As an implementation mode of the invention, step 2 includes: Step S201: for any group of longitudinal hole array optimization parameters of the micro-spray belt, a group of spray hole positions is randomly generated according to the parameters and the margin range of each hole, wherein each individual in the group of spray hole positions represents a hole position combination design scheme; the scheme includes: a fine-tuning value of the group hole spacing and a margin value of each side hole; Step S202, applying a genetic algorithm, taking the Christian uniformity of one side reaching 80% as the optimization target, performing selection, crossover and mutation operations on the nozzle hole position group, so that the group evolves continuously to obtain an optimized group, and for each individual in the optimized group, obtaining a nozzle hole spacing fine-tuning value according to its group hole spacing value, and taking the group hole spacing fine-tuning value, the nozzle hole spacing fine-tuning value and the margin value of the side hole as a group of nozzle hole position optimal parameters.

[0011] As an implementation mode of the invention, step S201 includes: (1) Determine the margin range L of each side hole i 0.1r <L i <0.8r, wherein r is 0.5 times the folded diameter of the micro-spraying tape; (2) According to the margin L of each side hole i And group hole spacing fine-tuning value S 11 , randomly generate the nozzle hole position group; the group hole spacing fine-tuning value S 11 The setting range is 0.8 S1 11 <1.2 S1.

[0012] As an implementation mode of the invention, step S202 includes: (1) Setting the end pressure P of the micro-spray belt N , calculate each individual from the end of the micro-spray strip to the upstream section by section, and obtain the pressure at each nozzle; (2) For each individual, the spray angle of each nozzle hole is calculated according to the margin value of each side hole in the individual; (3) according to the pressure at each nozzle hole obtained in step (1) and the spray angle of each hole obtained in step (2), based on the high-dimensional interpolation model of spray intensity, the spraying water depth distribution of each nozzle hole at different spray angles and different nozzle hole pressures is calculated; (4) The Christian uniformity CU, which is used to characterize the individual fitness, is calculated on one side of the micro-spray strip; (5) Re-sort the individuals from high to low according to the Christian uniformity CU; select and retain some excellent individuals according to the generation gap value, and then reorganize new individuals through crossover and mutation operations. According to steps (1) to (4), re-evaluate the fitness of the new individuals until the group size is reached;​ (6) If the maximum number of genetic generations is not exceeded, repeat step (5) for the new population to allow the population to evolve continuously and eventually obtain a high-quality population with high uniformity. The population composed of individuals with a Christian uniformity CU greater than 80% is taken as the optimized population.

[0013] As an embodiment of the invention, in step (2), the orifice injection angle of each hole is calculated according to the margin value of each hole using the following formula: ;in, θ i is the injection angle of the i-th orifice, L i is the margin of the i-th orifice; In step (4), the Christian uniformity CU is calculated according to the following formula: ; in: h i is the water depth per unit time of the i-th rain barrel, mm / h; is the average water depth of k effective rain barrels, mm / h; average water depth Calculated by the following formula: ; Among them, k is the number of effective rain barrels. When the water depth in the rain barrel is higher than 0.1mm, it is considered an effective rain barrel.

[0014] As an implementation mode of the invention, in step S202, for each individual in the optimization group, the nozzle hole spacing fine-tuning value is obtained by the following method: (7) Obtaining a total spacing value L corresponding to the optimization parameters of the longitudinal hole array of the micro-spray belt, wherein the total spacing value is obtained by summing the group hole spacing value and the spray hole spacing value; (8) Fine-tune the group hole spacing value, and obtain the corresponding nozzle hole spacing fine-tuning value after fine-tuning according to the following formula: ; Among them, S 21 is the fine-tuning value of the nozzle spacing; n is the number of nozzle groups.

[0015] The beneficial effects of adopting the above technical solution are: The micro-spray belt optimization design method based on genetic algorithm proposed in the present invention first determines the optimization parameters of the longitudinal hole array of the micro-spray belt with a pressure drop percentage of less than 20% according to step one, including the diameter of the spray hole, the number of holes in the hole group, the spacing between the holes in the hole group, and the spacing between the holes in the hole group. Then, based on each optimization scheme in step one, further search according to step two to obtain the optimization combination scheme of the fine-tuning values ​​of the spacing between the holes in multiple groups and the spacing between the spray holes, as well as the margin value of each side hole, to obtain multiple micro-spray belt optimization design schemes; obtain the actual spray width corresponding to the multiple micro-spray belt design schemes, and determine the optimal design scheme according to the actual spray width and the spray width of the micro-spray belt. The present invention uses the aperture and combination mode as optimization variables, and can automatically search for high-quality optimization configuration schemes through genetic algorithms according to the irrigation needs of the target crops, thereby avoiding complicated and inefficient repetitive work, and effectively achieving the optimization design of special micro-spray belts based on crop needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of a micro-spray belt provided in an embodiment of the present invention.

[0017] Figure 2 It is a schematic diagram for calculating the pressure and flow of a micro-spray belt provided in an embodiment of the present invention.

[0018] Figure 3 It is a schematic diagram of nozzle hole position calculation provided by an embodiment of the present invention.

[0019] Figure 4 It is a schematic diagram of the structure of a common micro-spray belt with a spray hole diameter of 40mm.

[0020] Figure 5 It is a schematic diagram of the structure of a common micro-spray belt with a spray hole diameter of 50mm. DETAILED DESCRIPTION

[0021] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention is clearly and completely described below in conjunction with specific embodiments.

[0022] The embodiment of the present invention provides a method for optimizing the design of a micro-spraying belt based on a genetic algorithm, the method comprising: Step 1: Determine the optimal parameters of the longitudinal hole array of the micro-spray belt: For a micro-spray belt with a length of 100 m, the nozzle diameter d, the number of holes in a group of holes n, the group hole spacing value S1, and the nozzle spacing value S2 set along the longitudinal direction of the micro-spray belt are used as variables to be optimized (such as Figure 1 As shown, S1 refers to the distance between the last hole of the previous group and the first hole of the current group, and S2 refers to the distance between two adjacent nozzles in the group. In addition, Figure 1It is only an illustration that the group of holes includes 5 nozzles, and the group of holes can also be 7, or other hole numbers that meet the requirements, and the present invention does not specifically limit this). The pressure drop percentage of the target micro-spray belt is used as the optimization target to determine the optimal parameters of the longitudinal hole array of the micro-spray belt, and the individuals with a pressure drop percentage of less than 20% are used as excellent alternatives; The range of the hole group spacing value S1 is 2-15 cm, the range of the nozzle hole spacing value S2 is 2-6 cm, and the range of the number of holes in the hole group n is an odd number of 3-15.

[0023] This step includes: Step S101: after determining the range of nozzle diameter, the range of the number of holes in a group of holes, the range of the distance between groups of holes, and the range of the distance between nozzles, a longitudinal hole array group is randomly generated. ， Each individual in the longitudinal hole array arrangement group represents a combination of a nozzle diameter, a number of holes in a group of holes, a group hole spacing value, and a nozzle hole spacing value; wherein the nozzle diameter range is obtained from the hole diameter range, and the number of holes in a group of holes, the group hole spacing value range, and the nozzle hole spacing value range are all determined by the designer according to needs; Among them, the range of the group hole spacing value is 2~15cm, the range of the nozzle hole spacing value is 2~6cm, and the number of holes in the group hole is an odd number ranging from 3 to 15; Step S102, taking the pressure drop percentage of the target micro-spray belt less than 20% as the optimization target, applying a genetic algorithm to select, crossover, and mutate the longitudinal hole array arrangement group, so that the group continues to evolve, and finally determining a plurality of optimized individuals, and taking the combination corresponding to each of the optimized individuals (specifically, a combination of the nozzle diameter d, the number of holes in the group hole n, the group hole spacing value S1, and the nozzle spacing value S2) as a group of micro-spray belt longitudinal hole array optimization parameters.

[0024] It includes: (1) Determine the total flow range, population size, maximum genetic generation, generation gap value, crossover rate, and mutation rate according to design requirements; (2) Setting the end pressure P of the target micro-spray belt N , calculate each individual from the end of the micro-spray belt upstream section by section, and obtain the head end pressure P1 and total flow Q1 corresponding to each individual; the end pressure P N Obtained from the working pressure; This step includes: A. For any individual, calculate the individual from the end of the micro-spray belt upstream section by section according to the following formula, based on the orifice pressure P at each nozzle i and orifice flow rate q i The head end pressure P1 is obtained (eg Figure 2 shown); ; When i is 2, the head end pressure P1 can be obtained; ; Among them, P i is the current nozzle pressure of hole i; P i-1 is the node pressure of nozzle i-1; i , S i and D are the resistance coefficient along the way, the distance between adjacent spray holes and the water filling diameter of the micro-spray belt, respectively; q i is the node flow rate of nozzle i, unit: cm 3 / s; pressure unit kPa, pressure range 36~98kPa; d i is the aperture, unit: mm; the aperture range is 0.3~0.7mm.

[0025] Along-the-line resistance coefficient λ i Calculated according to the following formula: Laminar flow area: ; Smooth area: ; Turbulent transition zone: ; Where Re is the Reynolds number.

[0026] B. Use the following formula to get the total flow Q1: ; Among them, Q i Q is the flow rate of the micro-spray main pipe between nozzle i and nozzle i-1; i-1 The flow rate of the micro-spray main pipe between nozzle i-1 and nozzle i-2; q i-1 is the node flow of nozzle i-1. When i is 2, the total flow Q1 can be obtained.

[0027] (3) According to the head end pressure P1, the fitness of each individual is calculated using the following formula: ; (4) Detect the total flow Q of each individual i Is it within the total flow range, such as Q i Does Q meet i [3,5]m 3 / h, if it is not within the total flow range, the fitness of the individual is set to a negative value; the total flow range is determined by the flow per hundred meters; (5) Sort the individuals from high to low according to their fitness, and select and retain the best individuals according to the generation gap value; then reorganize the new individuals through crossover and mutation operations, and evaluate the fitness of the new individuals according to steps (2)-(4) until the population size is reached; (6) If the maximum number of genetic generations is not exceeded, repeat step (5) for the new population to make the population evolve continuously, and finally obtain an excellent population with a very small pressure drop ratio along the process. Select individuals with a fitness value greater than 0.8 as optimized individuals and use them as the basic excellent solution for the optimization calculation of the nozzle hole position in step 2.

[0028] Step 2: Determine the optimal parameters of the micro-spray belt spray hole position: All optimized individuals obtained from step 1 have met the condition that the pressure drop ratio of the 100-meter micro-sprinkler belt is less than 20%. However, in actual sprinkler irrigation, it is found that when the sum of the spacing between the group holes S1 and the spacing between the nozzle holes S2 remains unchanged (such as Figure 3 As shown in the figure), without changing the number of holes n and the nozzle diameter D, the fine adjustment of the hole spacing S1 and the nozzle spacing S2 has little effect on the calculation of the longitudinal total flow and total pressure of the micro-spray belt, but has a significant impact on the spraying effect after the multi-hole stacking; in addition, the margin L of each nozzle i Determines the spray angle of the water jet i , the spray angle directly affects the spraying effect.

[0029] Therefore, the present invention selects the hole spacing S1 as an optimization variable for fine-tuning, and determines the optimal parameters for the arrangement of the spray belt margin holes, thereby obtaining design parameters that ensure higher spraying uniformity on both sides.

[0030] The following is a specific description of the steps, which include: Determine the margin range of the single-side side hole, optimize the parameters of any group of longitudinal hole arrays of the micro-spray belt, apply the genetic algorithm, take the single-side Christian uniformity of 80% as the optimization target, fine-tune the group hole spacing value according to the parameters and the margin range of the side holes, optimize the margin of each nozzle hole, and thus obtain the corresponding optimal parameters of the nozzle hole positions of several groups of micro-spray belts; the optimal parameters include: the margin of each nozzle hole, the fine-tuning value of the group hole spacing and the fine-tuning value of the nozzle hole spacing; Among them, in the present invention, the spray holes are divided into a central hole and a side hole, and the side holes are symmetrically arranged along the axis direction of the micro-spray belt, such as Figure 3 In the oblique 5-hole arrangement shown, the margins of the two side holes on both sides of the center hole are equal, so the margins of the two side holes are equal. L i Adjustable, so only the margins of the side holes on one side need to be optimized.

[0031] Specifically, it includes: Step S201: for any group of longitudinal hole array optimization parameters of the micro-spray belt, a group of spray hole positions is randomly generated according to the parameters and the margin range of each hole, wherein each individual in the group of spray hole positions represents a hole position combination design scheme; the scheme includes: a fine-tuning value of the group hole spacing, and a margin range value of each side hole; This step includes: (1) Determine the margin range L of each side hole i , the margin range is 0.1r <L i <0.8r, wherein r is 0.5 times the folded diameter of the micro-spray tape; Figure 3 As shown, the folded diameter refers to the total bandwidth that is not filled with water; (2) According to the margin L of each side hole i And group hole spacing fine-tuning value S 11 , randomly generate the nozzle hole position group; the group hole spacing fine-tuning value S 11 The setting range is 0.8 S1 11 <1.2 S1.

[0032] Step S202, taking the Christian uniformity of one side reaching 80% as the optimization target, performing selection, crossover and mutation operations on the nozzle hole position group, so that the group evolves continuously to obtain an optimized group, and for each individual in the optimized group, obtaining the nozzle hole spacing fine-tuning value according to its group hole spacing value, and taking the group hole spacing fine-tuning value, the nozzle hole spacing fine-tuning value and the margin value of the side hole as a group of nozzle hole position optimal parameters.

[0033] This step specifically includes: (1) Setting the end pressure P of the micro-spray belt N , calculate each individual from the end of the micro-spray strip to the upstream section by section, and obtain the pressure at each nozzle; Since the group hole spacing value S1 is fine-tuned in step S201 to obtain the group hole spacing fine-tuning value S 11 , therefore, the flow rate and pressure of each hole are also adjusted accordingly, and the flow rate and pore pressure of all holes of each individual need to be recalculated.

[0034] The obtaining method is similar to step (2) in the aforementioned step S102, and the present invention will not be repeated here.

[0035] (2) For any individual, the orifice spray angle of each hole is calculated according to the margin value of each side hole in the individual; In this step, the orifice injection angle of each hole is calculated according to the margin value of each hole using the following formula: ;in, θ i is the injection angle of the i-th orifice, L ​i is the margin of the ith orifice.

[0036] (3) Based on the pressure at each nozzle hole obtained in step (1) and the orifice injection angle of each hole obtained in step (2), a high-dimensional interpolation model of spray intensity is used to calculate the different apertures d i Pressure P at different injection angles and different nozzle holes i Spraying water depth h i Distribution of In this step, according to the standard pore size (d i =0.3,0.4,0.5,0.6,0.7mm) at different injection angles (30°~90°, step length 5°) and different working pressures ( P =30~100kPa, step length 10 kPa) spraying water depth h i The distribution data of the spraying depth is constructed by applying the cubic spline method, and the construction method can adopt the content disclosed in the Chinese invention patent with application number 202111322553.5.

[0037] (4) The Christian uniformity CU, which is used to characterize the individual fitness, is calculated on one side of the micro-spray strip; In this step, the Christian uniformity CU is calculated according to the following formula: ; in: h i is the water depth per unit time of the i-th rain barrel, mm / h; is the average water depth of k effective rain barrels, mm / h; average water depth Calculated by the following formula: ; Among them, k is the number of effective rain barrels. When the water depth in the rain barrel is higher than 0.1mm, it is considered an effective rain barrel.

[0038] The higher the Christian uniformity CU is, the better the spraying uniformity is. Therefore, the fitness function is determined to be the Christian uniformity CU.

[0039] (5) Re-sort the individuals from high to low according to the Christian uniformity CU; select and retain some excellent individuals according to the generation gap value, and then reorganize new individuals through crossover and mutation operations. According to steps (1) to (4), re-evaluate the fitness of the new individuals until the group size is reached; (6) If the maximum number of genetic generations is not exceeded, repeat step (5) for the new population to allow the population to evolve continuously and eventually obtain a high-quality population with high uniformity. The population composed of individuals with a Christian uniformity CU greater than 80% is taken as the optimized population.

[0040] Furthermore, for each individual in the optimization group, the nozzle spacing fine-tuning value is obtained by the following method: (7) Obtaining a total spacing value L corresponding to the optimization parameters of the longitudinal hole array of the micro-spray belt, wherein the total spacing value is obtained by summing the group hole spacing value and the spray hole spacing value; (8) Fine-tune the group hole spacing value, and obtain the corresponding nozzle hole spacing fine-tuning value after fine-tuning according to the following formula: ; Among them, S 21 is the fine-tuning value of the nozzle spacing; n is the number of nozzle groups.

[0041] Step 3: Determine the optimal design of the micro-spray belt: The nozzle diameter and the number of holes in the group of holes in the optimal parameters of the longitudinal hole array in step 1, and the fine-tuning value of the group hole spacing and the nozzle spacing fine-tuning value and the margin of the side holes corresponding to the optimal parameters of the group of longitudinal hole array in step 2 are used as a micro-spray belt optimization design scheme, and multiple micro-spray belt optimization design schemes can be obtained; The actual spray widths corresponding to the multiple micro-spray belt design schemes are obtained, and the optimal design scheme is determined according to the actual spray widths and the spray widths of the micro-spray belts.

[0042] Below, this method is used as an example to illustrate the design of a specific wheat-corn micro-spray belt product (made of PE, with a thickness of 0.2-0.3mm).

[0043] Parameter requirements: Micro-spraying belt spray width: 4-5m (double side) Micro-spray pipe diameter: 40mm Working pressure: 70Kpa Flow rate per 100 meters: 4-6m 3 / h Aperture: 0.4-0.6mm Maximum laying length: 100m According to the above parameter requirements, the method provided by the present invention is used to design a micro-spray belt product, and the obtained design parameters are shown in Table 1. Figure 4 and Figure 5 shown.

[0044] Table 1 Micro-spray belt structural parameters The invention also conducts field test on the micro-spraying belt with the design parameters.

[0045] 1. Test purpose: Hydraulic performance of new products of φ40 and φ50 ordinary micro-sprinkler belts 2. Project source: Project requirements in “Integration and Demonstration of Intensive Production Technology for Water-Saving and Efficiency-Enhancing Precision Irrigation Control for Wheat and Corn”.

[0046] 3. Environmental conditions: Temperature: 31°C; Humidity: 89%; Wind force: Level 1; Ground slope: 0° 4. Test location: Luquan Comprehensive Experimental Base, National Semi-arid Agricultural Engineering Technology Research Center 5. Test date: 16:30-17:00, August 1, 2023 The test results are shown in Table 2.

[0047] Table 2 Micro-sprinkler hydraulic performance test results The test results show that the hydraulic performance of the new products of φ40 (63mm folded diameter) and φ50 (80mm folded diameter) ordinary micro-sprinkler belts is at the leading level in China.

Claims

1. A micro-spray belt optimization design method based on genetic algorithm, characterized in that: The method comprises: Step 1: Determine the optimization parameters of the longitudinal hole array of the micro-spray belt: For a micro-spray belt with a length of 100m, according to the parameter requirements of the micro-spray belt, the diameter of the spray holes, the number of holes in a group of holes, the spacing between groups of holes, and the spacing between spray holes set along the longitudinal direction of the micro-spray belt are used as parameter variables to be optimized, and the pressure drop percentage of the target micro-spray belt is less than 20% as the optimization target, and the genetic algorithm is used to determine the optimization parameters of multiple groups of longitudinal hole arrays of micro-spray belts; the parameter requirements of the micro-spray belt include: spray width of the micro-spray belt, diameter of the micro-spray belt, working pressure, flow rate per 100 meters, and aperture range; Step 2: Determine the optimal parameters of the micro-spray belt spray hole position: Determine the margin range of the single-side side holes of the micro-spray belt, optimize the parameters of any group of longitudinal hole arrays of the micro-spray belt, apply the genetic algorithm, take the single-side Christian uniformity of 80% as the optimization target, fine-tune the group hole spacing value according to the parameters and the margin range of the side holes, optimize the margin of each nozzle hole, and thus obtain a corresponding group of optimal parameters for the nozzle hole positions of the micro-spray belt; the optimal parameters include: the margin of each nozzle hole, the fine-tuning value of the group hole spacing, and the fine-tuning value of the nozzle hole spacing; Step 3: Determine the optimal design of micro-spraying belt: The nozzle diameter and the number of holes in the group of holes in the optimal parameters of the longitudinal hole array in step 1, and the fine-tuning value of the group hole spacing and the nozzle spacing fine-tuning value corresponding to the optimal parameters of the group of longitudinal hole array in step 2, and the margin of the side holes are used as a micro-spray belt optimization design scheme to obtain multiple micro-spray belt optimization design schemes; The actual spray widths corresponding to the multiple micro-spray belt design schemes are obtained, and the optimal design scheme is determined according to the actual spray widths and the spray widths of the micro-spray belts.

2. The micro-spray belt optimization design method based on genetic algorithm according to claim 1 is characterized in that: Step one includes: Step S101: after determining the range of nozzle diameter, the range of the number of holes in a group of holes, the range of the distance between groups of holes, and the range of the distance between nozzles, a longitudinal hole array group is randomly generated. ， Each individual in the longitudinal hole array arrangement group represents a combination of a nozzle diameter, a number of holes in a group of holes, a group hole spacing value, and a nozzle hole spacing value; wherein the nozzle diameter range is obtained from the hole diameter range, and the number of holes in a group of holes, the group hole spacing value range, and the nozzle hole spacing value range are all determined by the designer according to needs; Step S102, taking the pressure drop percentage of the target micro-spray belt less than 20% as the optimization target, applying a genetic algorithm to perform selection, crossover, and mutation operations on the longitudinal hole array arrangement group, so that the group continues to evolve, and finally determining a plurality of optimized individuals, and using the combination method corresponding to each of the optimized individuals as a set of optimization parameters for the longitudinal hole array of the micro-spray belt.

3. The micro-spray belt optimization design method based on genetic algorithm according to claim 2 is characterized in that: in, The range of the group hole spacing value is 2~15cm, the range of the nozzle hole spacing value is 2~6cm, and the number of holes in the group hole ranges from 3 to 15 odd numbers.

4. The method for optimizing the design of micro-spraying belts based on genetic algorithm according to claim 2, characterized in that: Step S102 includes: (1) Determine the total flow range, population size, maximum genetic generation, generation gap value, crossover rate, and mutation rate according to design requirements; (2) Setting the end pressure P of the micro-spray belt N , calculate each individual from the end of the micro-spray belt upstream section by section, and obtain the head end pressure P1 and total flow Q1 corresponding to each individual; the end pressure P N Obtained from the working pressure; (3) According to the head end pressure P1, the fitness of each individual is calculated using the following formula: ； (4) Check whether the total flow rate Q1 of each individual is within the range of the total flow rate. If it is not within the range of the total flow rate, the fitness of the individual is set to a negative value; the range of the total flow rate is determined by the flow rate per 100 meters; (5) Sort the individuals from high to low according to their fitness, and select and retain the best individuals according to the generation gap value; then reorganize the new individuals through crossover and mutation operations, and evaluate the fitness of the new individuals according to steps (2)-(4) until the population size is reached; (6) If the maximum genetic generation is not exceeded, step (5) is repeated for the new population to allow the population to evolve continuously, and eventually an excellent population with a small pressure drop ratio along the process is obtained. Individuals with a fitness value greater than 0.8 are selected as optimized individuals and used as the basic excellent solution for the optimization calculation of the nozzle hole position in step 2.

5. The method for optimizing the design of micro-spraying belts based on genetic algorithm according to claim 4, characterized in that: Step (2) includes: A. For any individual, calculate the orifice pressure P at each nozzle section by section from the end of the micro-spray belt to the upstream according to the following formula: i and orifice flow rate q i Obtaining the head end pressure P1; ； ； Among them, P i is the current nozzle pressure of hole i; P i-1 is the node pressure of nozzle i-1; d i is the nozzle diameter; i , S i and D are the resistance coefficient along the way, the distance between adjacent spray holes and the water filling diameter of the micro-spray belt, respectively; q i is the node flow rate of nozzle i; Along-the-line resistance coefficient λ i Calculated according to the following formula: Laminar flow area: ; Smooth area: ; Turbulent transition zone: ; Where Re is the Reynolds number; B. Use the following formula to get the total flow Q1: ； Among them, Q i Q is the flow rate of the micro-spray main pipe between nozzle i and nozzle i-1; i-1 The flow rate of the micro-spray main pipe between nozzle i-1 and nozzle i-2; q i-1 is the node flow rate of nozzle i-1.

6. The method for optimizing the design of micro-spraying belts based on genetic algorithm according to claim 1, characterized in that: Step 2 includes: Step S201: for any group of longitudinal hole array optimization parameters of the micro-spray belt, a group of spray hole positions is randomly generated according to the parameters and the margin range of each hole, wherein each individual in the group of spray hole positions represents a hole position combination design scheme; the scheme includes: a fine-tuning value of the group hole spacing and a margin value of each side hole; Step S202, applying a genetic algorithm, taking the Christian uniformity of one side reaching 80% as the optimization target, performing selection, crossover and mutation operations on the nozzle hole position group, so that the group evolves continuously to obtain an optimized group, and for each individual in the optimized group, obtaining a nozzle hole spacing fine-tuning value according to its group hole spacing value, and taking the group hole spacing fine-tuning value, the nozzle hole spacing fine-tuning value and the margin value of the side hole as a group of nozzle hole position optimal parameters.

7. The method for optimizing the design of micro-spraying belts based on genetic algorithm according to claim 6, characterized in that: Step S201 includes: (1) Determine the margin range L of each side hole i 0.1r <L i <0.8r, wherein r is 0.5 times the folded diameter of the micro-spraying tape; (2) According to the margin L of each side hole i And group hole spacing fine-tuning value S 11 , randomly generate the nozzle hole position group; the group hole spacing fine-tuning value S 11 The setting range is 0.8 S1 < S 11 <1.2 S1.

8. The method for optimizing the design of micro-spraying belts based on genetic algorithm according to claim 6, characterized in that: Step S202 includes: (1) Setting the end pressure P of the micro-spray belt N , calculate each individual from the end of the micro-spray strip to the upstream section by section, and obtain the pressure at each nozzle; (2) For each individual, the spray angle of each nozzle hole is calculated according to the margin value of each side hole in the individual; (3) according to the pressure at each nozzle hole obtained in step (1) and the spray angle of each hole obtained in step (2), based on the high-dimensional interpolation model of spray intensity, the spraying water depth distribution of each nozzle hole at different spray angles and different nozzle hole pressures is calculated; (4) The Christian uniformity CU, which is used to characterize the individual fitness, is calculated on one side of the micro-spray strip; (5) Re-sort the individuals from high to low according to the Christian uniformity CU; select and retain some excellent individuals according to the generation gap value, and then reorganize new individuals through crossover and mutation operations. According to steps (1) to (4), re-evaluate the fitness of the new individuals until the group size is reached; (6) If the maximum number of genetic generations is not exceeded, repeat step (5) for the new population to allow the population to evolve continuously and eventually obtain a high-quality population with high uniformity. The population composed of individuals with a Christian uniformity CU greater than 80% is taken as the optimized population.

9. The method for optimizing the design of micro-spraying belts based on genetic algorithm according to claim 8, characterized in that: In step (2), the orifice injection angle of each hole is calculated according to the margin value of each hole using the following formula: ； in, θ i is the injection angle of the i-th orifice, L i is the margin of the i-th orifice; In step (4), the Christian uniformity CU is calculated according to the following formula: ； in: h i is the water depth per unit time of the i-th rain barrel, mm / h; is the average water depth of k effective rain barrels, mm / h; average water depth Calculated by the following formula: ； Among them, k is the number of effective rain barrels. When the water depth in the rain barrel is higher than 0.1mm, it is considered an effective rain barrel.

10. The method for optimizing the design of micro-spraying belts based on genetic algorithm according to claim 8, characterized in that: In step S202, for each individual in the optimization group, the nozzle hole spacing fine-tuning value is obtained by the following method: (7) Obtaining a total spacing value L corresponding to the optimization parameters of the longitudinal hole array of the micro-spray belt, wherein the total spacing value is obtained by summing the group hole spacing value and the spray hole spacing value; (8) Fine-tune the group hole spacing value, and obtain the corresponding nozzle hole spacing fine-tuning value after fine-tuning according to the following formula: ; Among them, S 21 is the fine-tuning value of the nozzle spacing; n is the number of nozzle groups.

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