Irrigation uniformity control method and system for micro-jet system

Abstract

The invention relates to a micro-spraying system irrigation uniformity control method and system, and belongs to the technical field of agricultural irrigation energy saving. Calculating the flow data of each nozzle according to the data of the flow meters of the branch pipes; calculating the pressure distribution of each node under the condition of no throttle valve by using the irrigation area pipe network hydraulic model, and finding out the part with too high or too low pressure in the pipe network; a throttle valve is installed on a main pipe of a pipe network in an irrigation area, and the opening degree of the throttle valve is adjusted and the pressure rise of a water pump is calculated by taking the most disadvantageous spray head in the pipe network as a pressure reference; the flow condition in the pipe network is monitored in real time through the flow meter, and data are uploaded; the pressure is calculated through the pipe network hydraulic model, when the water pressure in the pipe network is abnormal, the throttling valve needing to be adjusted and the opening degree are calculated, workers are informed, and early warning is conducted in time. The service life of the system is prolonged, and the irrigation efficiency and the water resource utilization rate are improved.

Description

Technical Field

[0001] The present invention relates to a method and system for controlling the irrigation uniformity of a micro-spray system, belonging to the technical field of energy conservation in agricultural irrigation. Background Art

[0002] The sprinkler irrigation system in farmland irrigation areas usually consists of a water pump, a pipe network, and sprinkler heads. Among them, the water pump provides power to transport water to the pipe network, and then it is evenly sprayed onto the farmland through the sprinkler heads. However, due to factors such as the pipe network layout and the output pressure of the water pump, the problem of uneven flow distribution often occurs in the sprinkler irrigation system. The sprinkler heads close to the main pipe or the water pump often receive excessive flow, resulting in waste of water resources; while the sprinkler heads at the end of the pipe network or far from the main pipe may have insufficient flow or even no water, affecting the irrigation effect, especially in large-scale irrigation areas.

[0003] In the prior art, such as Chinese Patent CN 118452052 B, a control method, device, and irrigation system for constant-pressure irrigation are disclosed, including an irrigation system with a water pump, a frequency adjustment module, an irrigation pipeline, and a pressure sensor. By obtaining the real-time pressure of the pipeline detected by the pressure sensor and comparing it with the target pressure of the irrigation pipeline, the operation frequency of the water pump is adjusted in a frequency modulation step by controlling the frequency adjustment module to achieve the purpose of constant-pressure control. The control method proposed in this patent involves the coordinated operation of multiple modules and components, and this complexity may increase the difficulty of system maintenance and fault troubleshooting. And frequently changing the operation frequency of the pump may lead to increased wear of the pump, thus shortening the service life of the water pump; at the same time, frequently changing the operation frequency of the pump will cause pressure fluctuations in the overall pipeline, affecting the water supply stability.

[0004] At the same time, although there are constant-flow sprinkler heads in the market that can maintain a constant water output within a certain pressure range, relying solely on the adjustment of the sprinkler heads is difficult to fundamentally solve the problem of uneven flow distribution in the pipe network. Summary of the Invention

[0005] The purpose of the present invention is to overcome the above deficiencies and provide a method and system for controlling the irrigation uniformity of a micro-spray system. By calculating and reasonably setting throttle valves, the effective control of the flow rate of the sprinkler heads is realized, ensuring that the pressure and flow rate at each sprinkler head are within a predetermined range.

[0006] The technical solution adopted by the present invention is as follows:

[0007] A method for controlling the irrigation uniformity of a micro-spray system, comprising the following steps:

[0008] S1. Collect data on the layout map of the irrigation area pipe network, pipe length, pipe diameter, pipe material, terrain height, water pump performance parameters, and information on the type, working pressure range, flow rate, and position of the sprinkler heads;

[0009] S2. Based on the principle of fluid mechanics, a hydraulic model of the irrigation district pipe network is established using pipe network model software to calculate the pressure distribution at different positions;

[0010] S3. Flow meters are installed at intervals on the branch main pipes of the irrigation district pipe network to record the flow conditions of the main branch pipes in the irrigation district pipe network and upload data in real time;

[0011] S4. Calculate the flow data of each sprinkler through the data of the flow meters on the branch main pipes; then use the model in step S2 to calculate the pressure distribution of each node without a throttle valve, and find out the parts of the pipe network with too high or too low pressure;

[0012] S5. Install throttle valves on the main pipes of the irrigation district pipe network. Based on the pressure of the most unfavorable sprinkler in the pipe network as the reference, calculate the adjustment of the throttle valve opening and the boost of the water pump:

[0013] a. If the pressure of the most unfavorable sprinkler in the irrigation district pipe network is less than the minimum allowable working pressure, it is necessary to increase the water pump pressure or replace the water pump with a larger lift to raise the pressure of the most unfavorable point sprinkler to an appropriate working pressure, and calculate the pressure that the water pump needs to increase;

[0014] b. If the pressure of the most unfavorable sprinkler in the irrigation district pipe network is greater than the working pressure range of the sprinkler, or the actual pressure of some sprinklers in the pipe network is greater than the pressure working range, then use the throttle valve to adjust and reduce the pressure to ensure that the pressure of each sprinkler in the irrigation pipe network is within the working pressure to the greatest extent, and calculate the opening of the throttle valve;

[0015] S6. Real-time monitor the flow conditions in the pipe network through the flow meter and upload data; calculate the pressure through the pipe network hydraulic model. When the water pressure in the pipe network is abnormal, calculate the throttle valve that needs to be adjusted and its opening, notify the staff and give an early warning in time, so as to realize the uniform control of the flow rate at each place in the irrigation pipe network.

[0016] In the above method, for the calculation of the pressure of each node in the irrigation district pipe network in the model described in step S4, the method is as follows:

[0017] (1) Monitor the data through the flow meter, and calculate the average outlet flow of the sprinklers between this flow meter and the previous flow meter and the flow velocity of each pipe section;

[0018] (2) According to the Darcy-Weisbach formula, the calculation formula for the pipe friction loss ΔP is as follows:

[0019]

[0020] Among them, λ is the friction coefficient; L is the pipe length, in m; D is the pipe diameter, in m; ρ is the density of water, in units of (kg / m 3 ); v is the flow velocity, in m / s;

[0021] (3) According to the pipeline Bernoulli equation:

[0022]

[0023] Among them, P1 and P2 are the pressures at both ends of the pipeline respectively, ρ is the density of water, v1 and v2 are the flow velocities at both ends of the pipeline respectively, h1 and h2 are the height differences at both ends of the pipeline respectively, and ΔP is the pipeline friction loss.

[0024]

[0025] Calculate the pressure conditions of each node from the water pump end to the nozzles at the end of the pipe network through the above formula, and finally deduce the pressure conditions between each node in the pipe network and the most unfavorable nozzle.

[0026] For the determination of the throttle valve opening in step S5, first calculate the pressure drop ΔP before and after the throttle valve, then:

[0027]

[0028] Among them, Δp is the pressure drop at both ends of the throttle valve; K is the flow coefficient, which needs to be determined by referring to the data provided by the manufacturer of the throttle valve; v is the flow velocity through the throttle valve orifice; g is the acceleration of gravity (usually taken as 9.8 m / s 2 );

[0029] The flow velocity v is calculated through the following formula:

[0030]

[0031] Among them, Q is the flow rate (the volume of fluid passing through the throttle valve per unit time), and A is the flow area of the throttle valve;

[0032] Solve the flow area A of the throttle valve through the above formula to obtain the opening of the throttle valve.

[0033] Another object of the present invention is to provide a micro-sprinkler irrigation uniformity control system, including a hydraulic model construction module for the irrigation area pipe network, which is used to collect the layout map of the irrigation area pipe network, pipe length, pipe diameter, friction coefficient, terrain height data, water pump performance parameters, and nozzle type and position information, and establish a hydraulic model of the irrigation area pipe network based on the principles of fluid mechanics using pipe network model software;

[0034] A flow rate acquisition and transmission module, which is used to monitor the flow rate in the pipe network in real time and upload data;

[0035] A pressure distribution calculation module, which is used to calculate the pressure distribution of each node without a throttle valve under the common outlet pressure of the water pump during irrigation using the hydraulic model of the irrigation area pipe network;

[0036] The overpressure or underpressure node analysis module is used to compare with the pressure range at the nozzle outlet of the irrigation pipeline, find out the parts with excessive or insufficient pressure in the pipe network, and analyze the node areas with excessive pressure or insufficient pressure according to the calculation results;

[0037] The throttle valve setting and opening calculation module is used to select a suitable position to set the throttle valve in the node area with excessive pressure and calculate the throttle valve opening to reduce the flow rate and pressure;

[0038] The water pump setting and pressure boost calculation module is used to select a suitable position to set the water pump or change the pump pressure in the node area with insufficient pressure, raise the pressure of the nozzle at the most unfavorable point to a suitable working pressure, ensure that the pressure of all nozzles is within the working pressure range, and calculate the pressure that the water pump needs to raise;

[0039] The early warning module, when the water pressure in the pipe network is abnormal, calculates the throttle valve that needs to be adjusted and its opening, notifies the staff and gives an early warning.

[0040] The flow rate acquisition and transmission module transmits the detection results to the remote end through GPRS or local area network. The remote end can be but is not limited to the mobile phone end, PC end and water service cloud platform, and it can receive the analysis results at the remote terminal through wireless communication technology. In case of abnormal situations, give an early warning in time and notify the staff to handle.

[0041] Compared with the prior art, the beneficial effects of the present invention are:

[0042] (1) It can avoid the aggravation of the wear of the pump motor caused by the frequent change of the operating frequency of the water pump, improve the service life of the water pump, and shorten the maintenance cost of the equipment; it can also avoid the pressure fluctuation of the entire irrigation pipe network caused by the frequency modulation of the water pump, reduce the water hammer impact, improve the operation stability of the pipe network, and reduce the risk of pipe network damage; thus avoiding the damage to the equipment (including nozzles, pipes, etc.) caused by unstable working conditions and extending the service life of the system.

[0043] (2) It improves the irrigation efficiency and water resource utilization rate, ensures that the pressure and flow rate at each nozzle are within the predetermined range, avoids the uneven irrigation phenomenon caused by the water flow fluctuation, and reduces the waste of water resources. Description of the Drawings

[0044] Figure 1 is the method flow chart of the present invention;

[0045] Figure 2 is the schematic diagram of the regional irrigation pipe network in the embodiment of the invention.

[0046] Among them: 1. Water storage tank; 2. Main pipe total valve; 3. Water pump; 4. Check valve; 5. Irrigation main pipe; 6. Branch main pipe in the irrigation area; 7. Branch main pipe valve; 8. Branch pipe in the irrigation area; 9. Sprinkler head; 10. Remote transmission flowmeter; 11. Throttle valve. Detailed implementation manner

[0047] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0048] Embodiment 1 A method for controlling the irrigation uniformity of a micro-spray system, including the steps ( Figure 1 as shown) are as follows:

[0049] S1. Collect the layout map of the pipe network in the irrigation area, pipe length, pipe diameter, pipe material, terrain height data, water pump performance parameters (such as head, flow rate, etc.), and the type, working pressure range, flow rate and position information of the sprinkler heads.

[0050] S2. Based on the principle of fluid mechanics, use pipe network model software (such as EPANET, etc.) to establish a hydraulic model of the pipe network in the irrigation area for calculating the pressure distribution at different positions:

[0051] Figure 2 This is the distribution map of the regional pipe network in this embodiment. There is no elevation change in the pipe network, and all pipe materials are plastic pipes. The pipe diameter of the branch pipes connecting the sprinkler heads is 20 mm, and the most unfavorable sprinkler head in the irrigation pipe network is located at point I.

[0052] Construct a hydraulic model of the pipe network by collecting the pipe diameter, material, pipe specific resistance and pipe distribution of each pipeline in the pipe network. The specific parameters are shown in Table 1.

[0053] Table 1. Information table of the pipe network hydraulic model

[0054] Pipe section number Pipe diameter (m) Pipe length (m) Pipe material Pump - A 0.10 18 Plastic pipe A - B 0.08 41 Plastic pipe B - C 0.05 16 Plastic pipe C - D 0.05 16 Plastic pipe D - E 0.05 16 Plastic pipe E - F 0.04 16 Plastic pipe F - G 0.025 16 Plastic pipe G - H 0.02 8 Plastic pipe H - I 0.02 16 Plastic pipe

[0055] S3. Install flowmeters at intervals on the branch main pipes of the pipe network in the irrigation area to record the flow conditions of the main branch pipes in the pipe network in the irrigation area and upload the data in real time:

[0056] Install flowmeters on the branch main pipes of the pipe network in the irrigation area, and install 1 flowmeter every 2 - 3 branch pipes. In this embodiment, install flowmeters at nodes F, D and the left end of B to record the flow conditions in the pipe network in the irrigation area and upload the data in real time. The flowmeter transmits the detection result to the remote end through GPRS or local area network.

[0057] The flowmeter transmits the detection result to the remote end through GPRS or local area network. Assume that the flowmeter data at node F is 5.6 m 3 / h, the flow data at node D is 11.2 m 3 / h, and the flowmeter data at node B is 17.6 m 3 / h.

[0058] S4. Calculate the flow rate data of each nozzle based on the data of the flow meters on the branch pipes; then use the model in step S2 to calculate the pressure distribution of each node without a throttle valve, and identify the parts of the pipe network with excessively high or low pressure:

[0059] In this embodiment, the working pressure of the nozzle is 0.12 - 0.18 Mpa, and the flow rate is 0.7 m 3 / h.

[0060] (1) Nozzle flow rate calculation: The flow meter transmits the detection results to the remote end through GPRS or a local area network. Assume that the flow meter data of node F is 5.6 m 3 / h, the flow rate data of node D is 11.2 m 3 / h, and the flow meter data at node B is 17.6 m 3 / h. Therefore, the average flow rate of the nozzles after node E is 0.7 m 3 / h, the average flow rate of the nozzles between node E and node C is 0.7 m 3 / h, and the average flow rate of the nozzles between node B and node C is 0.8 m 3 / h. The calculation method is as follows:

[0061] ① The flow meter data at node F is 5.6 m 3 / h. There are 8 nozzles in front of this flow meter. Therefore, the single average flow rate of the 8 nozzles in front of node F is 0.7 m 3 / h.

[0062] ② The flow meter data at node D is 11.2 m 3 / h. Subtract the flow meter data at node F, which is 5.6 m 3 / h. Therefore, the single average flow rate of the 8 nozzles between node F and node D is 0.7 m 3 / h.

[0063] ③ The flow meter data at node B is 17.6 m 3 / h. Subtract the flow meter data at node D, which is 6.4 m 3 / h. Therefore, the single average flow rate of the 8 nozzles between node B and node D is 0.8 m 3 / h.

[0064] (2) Calculation of pipe friction loss ΔP:

[0065] Taking the most unfavorable nozzle I in the pipe network as the reference, calculate the flow velocity and friction loss of each pipe section in the pipe network.

[0066] According to the Darcy - Weisbach formula, the calculation formula for the pipe friction loss ΔP is as follows:

[0067]

[0068] Among them, λ is the friction coefficient; L is the pipe length, in m; D is the pipe diameter, in m; ρ is the density of water, in (kg / m 3 ); v is the flow velocity, in m / s;

[0069] The calculation results are shown in Table 2:

[0070] Table 2. Calculation Table of Pipe Network Flow Velocity and Friction Loss

[0071] Pipe section number Pipe diameter (m) Pipe length Flow rate Flow velocity Friction coefficient ΔP (kPa) Pump - A 0.1 18 35.2 1.25 0.02 2.79 A - B 0.08 41 17.6 0.97 0.02 4.85 B - C 0.05 16 14.4 2.04 0.02 13.29 C - D 0.05 16 11.2 1.59 0.02 8.04 D - E 0.05 16 8.4 1.19 0.02 4.52 E - F 0.04 16 5.6 1.24 0.02 6.14 F - G 0.04 16 2.8 0.62 0.02 1.53 G - H 0.02 8 1.4 1.24 0.02 6.14 H - I 0.02 16 0.7 0.62 0.02 3.07

[0072] (3) According to the pipe Bernoulli equation:

[0073]

[0074] Among them, P1 and P2 are the pressures at both ends of the pipe respectively, ρ is the density of water, v1 and v2 are the flow velocities at both ends of the pipe respectively, h1 and h2 are the height differences at both ends of the pipe respectively, and ΔP is the pipe friction loss.

[0075] Assume that the elevations of all points in the irrigation area pipe network in this embodiment are the same, then the calculation formula is:

[0076]

[0077] Assume that the pump outlet pressure is 0.21 Ma, and the flow velocity at the node during calculation is taken as the flow velocity of the pipe section at the left end or lower end of the node. The calculation results of the pressures at each node are as follows:

[0078] Node label Pump A B C D E F G H I Pressure (MPa) 0.210 0.207 0.203 0.188 0.181 0.177 0.170 0.169 0.163 0.160

[0079] From the working pressure range of the nozzle 0.12 - 0.18 Mpa, it can be seen that the nozzles before node D are all over-pressurized and need to be depressurized.

[0080] S5. Install a throttle valve on the main pipe of the irrigation area pipe network, and take the pressure of the most unfavorable nozzle in the pipe network as the pressure reference to calculate the throttle valve opening adjustment and pump boost:

[0081] a. If in the irrigation area pipe network, the pressure of the most unfavorable nozzle in the pipe network is less than the minimum allowable working pressure, it is necessary to increase the pump pressure or replace the pump with a larger head to raise the pressure of the most unfavorable nozzle to the appropriate working pressure, and calculate the pressure that the pump needs to increase. This situation is not listed in this embodiment;

[0082] b. If in the irrigation area pipe network, the pressure of the most unfavorable nozzle in the pipe network is greater than the working pressure range of the nozzle, or the actual pressure of some nozzles in the pipe network is greater than the pressure working range, use the throttle valve to adjust and depressurize to ensure that the pressures of all nozzles in the irrigation pipe network are within the working pressure to the greatest extent, and calculate the opening of the throttle valve;

[0083] Install a throttle valve on the left side of node A, and calculate the opening of the throttle valve based on the pipe network pressure in step S4.

[0084] After calculation, the working pressure of the second sprinkler above node B is 0.200 Mpa, and it is necessary to reduce the working pressure at this place by 0.02 Mpa, that is, the overall pressure of the pipe network is reduced by 0.02 Mpa.

[0085] From the formula we get

[0086]

[0087] Note: The value of K needs to be determined according to the valve type, opening and manufacturer's data. In this embodiment, K = 50 is taken.

[0088] From we get A = Q / v = (0.0098 / 88.5) = 0.00011 m 2 = 11 mm 2

[0089] Therefore, in this embodiment, the opening of the throttle valve is 11 mm 2 .

[0090] S6. Real-time monitor the flow situation in the pipe network through a flowmeter and upload data; through the calculation and analysis of the pipe network hydraulic model, when the water pressure in the pipe network is abnormal, the pipe network hydraulic model calculates the throttle valve and its opening that need to be adjusted, notifies the staff and gives an early warning in time. After receiving the control instruction, the staff conducts the maintenance of the pipe network or adjusts the opening of the throttle valve, so as to realize the uniform control of the flow rate at each place of the irrigation pipe network.

[0091] Embodiment 2 A control system for the irrigation uniformity of a micro-spray system, including a module for constructing a hydraulic model of the irrigation area pipe network, which is used to collect the layout map of the irrigation area pipe network, pipe length, pipe diameter, friction coefficient, terrain height data, pump performance parameters, and sprinkler type and position information, and establish a hydraulic model of the irrigation area pipe network by using pipe network model software based on the principle of fluid mechanics;

[0092] A flow rate acquisition and transmission module, which is used to real-time monitor the flow situation in the pipe network and upload data;

[0093] A pressure distribution calculation module, which is used to calculate the pressure distribution of each node without a throttle valve under the common outlet pressure of the water pump during irrigation;

[0094] A module for analyzing nodes with excessive or too low pressure, which is used to compare with the pressure range at the outlet of the sprinkler of the irrigation pipeline, find out the parts of the pipe network with excessive or too low pressure, and analyze the node areas with excessive pressure or too low pressure according to the calculation results;

[0095] The throttle valve setting and opening calculation module is used to select a suitable position to set the throttle valve in the node area with excessive pressure and calculate the throttle valve opening to reduce the flow rate and pressure;

[0096] The water pump setting and pressure boost calculation module is used to raise the pressure of the sprinkler at the most unfavorable point to a suitable working pressure and calculate the pressure that the water pump needs to raise;

[0097] The early warning module, when it is calculated through the pipe network hydraulic calculation model that the pressure in the pipe network is abnormal, calculates the throttle valve that needs to be adjusted and the opening, notifies the staff and gives an early warning.

[0098] The flow rate acquisition and transmission module transmits the detection results to the remote end through GPRS or local area network. The remote end can be, but is not limited to, the mobile phone end, the PC end and the water service cloud platform, and it can receive the analysis results at the remote terminal through wireless communication technology. In case of abnormal situations, an early warning is given in time to notify the staff to handle.

[0099] The above is only the specific implementation manner of the present invention and is not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for controlling the irrigation uniformity of a micro-spraying system, characterized in that The steps are as follows: S1. Collect the layout diagram of the irrigation district pipe network, pipe length, pipe diameter, pipe material, terrain height data, pump performance parameters, and sprinkler type, working pressure range, flow rate, and position information; S2. Based on the principles of fluid mechanics, use pipe network model software to establish a hydraulic model of the irrigation district pipe network for calculating the pressure distribution at different positions; S3. Install flow meters at intervals on the branch main pipes of the irrigation district pipe network to record the flow rate of the main branch pipes in the irrigation district pipe network and upload data in real time; S4. Calculate the flow rate data of each sprinkler through the data of the flow meters on the branch main pipes; then use the model in step S2 to calculate the pressure distribution of each node without a throttle valve, and find out the parts of the pipe network with too high or too low pressure; S5. Install throttle valves on the main pipes of the irrigation district pipe network. Based on the pressure of the most unfavorable sprinkler in the pipe network, calculate the adjustment of the throttle valve opening and the boost of the pump: a. If in the irrigation district pipe network, the pressure of the most unfavorable sprinkler is less than the minimum allowable working pressure, it is necessary to increase the pump pressure or replace the pump with a larger head to raise the pressure of the most unfavorable point sprinkler to a suitable working pressure, and calculate the pressure that the pump needs to increase; b. If in the irrigation district pipe network, the pressure of the most unfavorable sprinkler is greater than the working pressure range of the sprinkler, or the actual pressure of a sprinkler in the pipe network is greater than the pressure working range, then use the throttle valve to adjust and reduce the pressure to ensure that the pressure of each sprinkler in the irrigation pipe network is within the working pressure to the greatest extent, and calculate the opening of the throttle valve; S6. Real-time monitor the flow rate in the pipe network through the flow meter and upload data; calculate the pressure through the pipe network hydraulic model. When the water pressure in the pipe network is abnormal, calculate the throttle valve that needs to be adjusted and its opening, notify the staff and give a timely warning, so as to realize the uniform control of the flow rate at each place in the irrigation pipe network.

2. The method for controlling the irrigation uniformity of a micro-spraying system according to claim 1, characterized in that, For the calculation of the pressure distribution of each node in the irrigation district pipe network in the model described in step S4, the method is as follows: (1) Monitor the data through the flow meter and calculate the average outlet flow rate of the sprinklers between this flow meter and the previous flow meter and the flow velocity of each pipe section; (2) According to the Darcy-Weisbach formula, the calculation formula for the pipe friction loss ΔP is as follows: where λ is the friction coefficient; L is the pipe length, in m; D is the pipe diameter, in m; ρ is the density of water; v is the flow velocity, in m / s; (3) According to the pipe Bernoulli equation: where P1 and P2 are the pressures at both ends of the pipe respectively, ρ is the density of water, v1 and v2 are the flow velocities at both ends of the pipe respectively, h1 and h2 are the height differences at both ends of the pipe respectively, and ΔP is the pipe friction loss. Calculate the pressure conditions of each node from the pump end to the sprinkler at the end of the pipe network through the above formulas, and finally deduce the pressure conditions of each node in the pipe network and the most unfavorable sprinkler.

3. A method for controlling the irrigation uniformity of a microspray system according to claim 1, characterized in that, For the determination of the throttle valve opening in step S5, first calculate the pressure drop ΔP before and after the throttle valve, then: where ΔP is the pressure drop across the throttle valve; K is the flow coefficient, which needs to be determined by referring to the data provided by the throttle valve manufacturer; v is the flow velocity through the throttle valve orifice; g is the acceleration due to gravity; The flow velocity v is calculated by the following formula: where Q is the flow rate and A is the flow area of the throttle valve; The opening of the throttle valve can be obtained by solving the flow area A of the throttle valve through the above formula.

4. A micro-spray system irrigation uniformity control system, characterized in that, It includes an irrigation district pipe network hydraulic model construction module, which is used to collect the layout diagram of the irrigation district pipe network, pipe length, pipe diameter, friction coefficient, terrain height data, pump performance parameters, and sprinkler type and position information, and establish an irrigation district pipe network hydraulic model using pipe network model software based on the principles of fluid mechanics; A flow rate acquisition and transmission module, which is used to monitor the flow rate situation in the pipe network in real time and upload data; A pressure distribution calculation module, which is used to calculate the pressure distribution of each node without a throttle valve using the irrigation district pipe network hydraulic model under the common outlet pressure of the pump during irrigation; A node analysis module for excessive or insufficient pressure, which is used to compare with the pressure range at the outlet of the sprinkler of the irrigation pipeline, find out the parts of the pipe network with excessive or insufficient pressure, and analyze the node areas with excessive pressure or insufficient pressure according to the calculation results; A throttle valve setting and opening calculation module, which is used to select a suitable position to set a throttle valve for the node area with excessive pressure and calculate the throttle valve opening to reduce the flow rate and pressure; A pump setting and pressure boost calculation module, which is used to select a suitable position to set a pump or change the pump pressure for the node area with insufficient pressure, raise the pressure of the sprinkler at the most unfavorable point to a suitable working pressure, ensure that the pressure of all sprinklers is within the working pressure range, and calculate the pressure that the pump needs to increase; An early warning module, when the water pressure in the pipe network is abnormal, calculates the throttle valve and opening that need to be adjusted, notifies the staff and gives an early warning.

5. The irrigation uniformity control system of a micro-spraying system according to claim 4, characterized in that, The flow rate acquisition and transmission module transmits the detection results to the remote end through GPRS or a local area network.

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