Yellow diversion drip irrigation light filtering head system and design method thereof

Abstract

The invention discloses a yellow diversion drip irrigation light filtration head system and a design method thereof.The yellow diversion drip irrigation light filtration head system comprises a water inlet channel, a gate and a trash holding device, the gate and the trash holding device are arranged on the water inlet channel, the water inlet channel is communicated with a desilting device, and the bottom of the desilting device is communicated with a ground irrigation system through a slurry pump; the desilting device is communicated with the wet pump chamber, a submersible pump in the wet pump chamber is connected with the filtering device, the filtering device is communicated with the ground drip irrigation system, and the grain size of silt entering the ground drip irrigation system is larger than 125 micrometers and smaller than 200 micrometers so that light filtering can be achieved. According to the scheme, the water for flushing the silt in the desilting device and the settled silt are input into the irrigation area through ground irrigation, a desilting basin does not need to be arranged in the irrigation area, and the problems that an existing desilting basin is large in occupied area, high in construction cost and inconvenient to desilt, and the treatment pertinence of the head of the Yellow River water is not high can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of agricultural irrigation water treatment, and in particular to a Yellow River drip irrigation light filtration head system and a design method thereof. Background Art

[0002] The way Yellow River sediment is handled and regulated affects the performance of drip irrigation systems. Currently, most Yellow River water diversion drip irrigation systems utilize a complex multi-stage filtration system consisting of large sedimentation basins, headwater filtration, and field filtration. Sedimentation projects typically occupy 0.3% to 0.6% of the designed irrigation area. Currently, existing lakes, ponds, abandoned ditches, and salt wastelands are often used as sedimentation basins, achieving a sediment treatment rate of over 80%. However, the large area required for sedimentation basins, their high construction costs, and the high cost of dredging have hindered the widespread adoption of drip irrigation technology. Furthermore, land resources for large sedimentation basins are often lacking in areas with high-standard farmland, making this a limiting factor in the adoption of drip irrigation.

[0003] At present, the standard for drip irrigation of the Yellow River is that the first treated water of the Yellow River must reach the target particle size of 125μm (120 mesh) or the sediment treatment rate must be above 80% before it is sent to the field for drip irrigation. The drip irrigation of annual crops using the Yellow River generally uses disposable drip irrigation tapes. Experience has shown that when the particle size is less than 200μm and the sediment content is 4kg / m 3 Under the water source conditions, the flow rate attenuation of the drip irrigation device during the growth period of a single crop is less than 20%, which is a mild blockage. At this time, it can also meet the irrigation needs of a single crop during the growth period. That is, when drip irrigation is carried out with a disposable drip irrigation belt, the water in the drip irrigation does not necessarily have to reach the standard of 125μm. This means that there is excessive filtration to a certain extent, which increases the cost of water filtration.

[0004] In summary, there is an urgent need to develop a Yellow River drip irrigation filtration system that can reduce floor space, reduce dredging costs, and reduce water filtration costs. Summary of the Invention

[0005] In response to existing problems, the Yellow River drip irrigation light filtration head system and its design method provided by the present invention can achieve the purpose of sand removal by lightly treating the Yellow River sediment. At the same time, the discharged sediment water can be used for ground irrigation, realizing the resource utilization of sediment.

[0006] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is:

[0007] In the first aspect, a light filtering head system for the Yellow River diversion drip irrigation is provided, which includes an intake channel, a gate and a trash rack arranged on the intake channel. The intake channel is connected to a sedimentation device, and the bottom of the sedimentation device is connected to a surface irrigation system through a slurry pump; the sedimentation device is connected to a wet pump chamber, and a submersible pump in the wet pump chamber is connected to a filtering device, and the filtering device is connected to a surface drip irrigation system. The sediment particle size entering the surface drip irrigation system is greater than 125 μm and less than 200 μm to achieve light filtering.

[0008] Further, the sedimentation device includes a plurality of modular sedimentation tanks arranged in a rectangular array. A sedimentation funnel is provided at the bottom of each modular sedimentation tank, and each sedimentation funnel is connected to a slurry pump through a sand discharge pipe; a sludge level gauge and an ultrasonic vibrator are arranged in the sedimentation funnel, and electromagnetic valves are arranged on the sand discharge pipes adjacent to the sedimentation funnel. The slurry pump, the submersible pump, the sludge level gauge, the ultrasonic vibrator and the electromagnetic valve are all connected to a controller.

[0009] Further, the light filtering head system for the Yellow River diversion drip irrigation further includes a dry pump chamber for arranging the slurry pump. Observation windows are provided at the tops of both the dry pump chamber and the wet pump chamber; the filtering device is a centrifugal screen composite filter, and a box support is arranged outside the modular sedimentation tank.

[0010] In the second aspect, a design method for a light filtering head system for the Yellow River diversion drip irrigation is provided, which includes the steps:

[0011] S1. Determine the drip irrigation area, surface irrigation area, designed total diversion flow rate and drip irrigation diversion flow rate based on water-sediment coordination;

[0012] S2. Determine the target particle size when the flow rate attenuation is less than a preset ratio according to the dripper size and irrigation period of the drip irrigation tape;

[0013] S3. Determine the working height range of the sedimentation device according to the average depth of the working water level, and determine the working width range of the sedimentation device based on the working height range;

[0014] S4. Try to calculate the optimal cross-sectional area of water flow according to the working height range and the working width range, determine the working height, and calculate the working width based on the working height;

[0015] S5. Calculate the sediment settling velocity of the sediment according to the target particle size; then calculate the settling time according to the sediment settling velocity and the working height;

[0016] S6. Calculate the working length of the sedimentation device according to the settling time and the sediment transport velocity.

[0017] Further, the expression for calculating the working width based on the working height is:

[0018]

[0019] Among them, B is the working width; H is the working height; Q s is the total designed diversion flow rate; v is the sediment transport velocity; A1 is the drip irrigation area.

[0020] Furthermore, the expression for calculating the drip irrigation area is:

[0021] K = 1 + Q s1 Tt d

[0022] Among them, η t is the field water utilization coefficient; η g is the pipeline water utilization coefficient; f is the scouring water coefficient; F is the allowable reservoir siltation coefficient; K is the recharge coefficient within the rotation irrigation period; T i is the designed irrigation cycle for the i-th crop; E ci is the designed water consumption intensity of the i-th crop; a i is the area proportion of the i-th crop; M is the types of crops for irrigation; t d is the designed daily water supply hours; T is the designed irrigation cycle.

[0023] Furthermore, according to the target particle size, the method for calculating the sediment settling velocity of the sediment is:

[0024] When the target particle size ≤ 0.062 mm, the expression for calculating the sediment settling velocity is:

[0025]

[0026] Among them, ω is the sediment settling velocity; g is the acceleration due to gravity; ρ s is the sediment density; ρ w is the clear water density; d is the target particle size; v n is the kinematic viscosity of water; t is the water temperature;

[0027] When 0.062 < target particle size ≤ 2.0 mm, the expression for calculating the sediment settling velocity is:

[0028] (lgS a + 3.790) 2 +(lgψ - 5.777) 2 = 39.0

[0029]

[0030] Among them, S a is the settling velocity criterion; ψ is the particle size criterion.

[0031] Furthermore, the expression for calculating the working length of the sedimentation device is:

[0032] L = 1.2vt c

[0033] Wherein, L is the working length; t c is the sedimentation time; v is the sediment transport velocity.

[0034] Furthermore, the design method of this solution also includes:

[0035] Calculate the designed sediment content S to be treated according to the target particle size and characteristic particle size D :

[0036]

[0037] Wherein, d is the target particle size; d 97 is the characteristic particle size; m is an exponent that varies with the fineness of sediment particles;

[0038] Calculate the designed sediment treatment rate η according to the designed sediment content to be treated L :

[0039]

[0040] Wherein, S b is the sediment content in the water source;

[0041] Filter the water passing through the sedimentation device with sieves of different meshes, collect the sediment content in the filtered effluent, and then calculate the sedimentation rate E1:

[0042]

[0043] Wherein, Q1 is the effluent flow rate; S0 is the sediment content in the inlet channel; S1 is the sediment content in the effluent; Q0 is the total flow rate of the water coming from the channel;

[0044] Calculate the sedimentation rate E1 closest to the designed sediment treatment rate η among multiple sedimentation rates E1 L and use the sieve corresponding to it as the sieve finally selected for the filtering device.

[0045] Furthermore, the design method of this solution also includes calculating the sediment discharge time for equal flow velocity sediment discharge according to the dead volume and working width of the sedimentation device:

[0046]

[0047] Wherein, T ps is the sediment discharge time; γ s is the sediment specific gravity; V s is the dead volume of the sedimentation device; ρ c is the sediment content in the scouring water flow; q c is the unit-width scouring flow rate; B is the working width.

[0048] The beneficial effects of the present invention are as follows: Through the three-stage cooperation of the rotary trash rack, the sedimentation box body, and the filter, the sediment particle size entering the surface drip irrigation system can be made to be greater than 125 μm and less than 200 μm to achieve light filtration; by processing in this way, a complex filtration system is not required, and the filtration cost can be significantly reduced; in this solution, the water for flushing the sediment in the sediment flushing device and the sediment settled down are input into the irrigation area through surface irrigation, so that the sediment can be utilized, and the water for flushing the sediment enters the irrigation area as irrigation water, saving the cost of dredging; at the same time, there is no need to design a sedimentation tank, greatly reducing the floor area of the filtration system, thus facilitating the popularization of the Yellow River diversion drip irrigation.

[0049] When designing the light filtration head system of this solution, the target particle size is determined by the drip head size and irrigation cycle of the drip irrigation tape, ensuring that the sediment can pass through the drip head normally while not requiring excessive filtration, to a certain extent reducing the water filtration cost; based on the determined target particle size, the working length of the sedimentation device is designed, which can ensure that the sediment in the water reaches the target particle size at this length and ensure the sedimentation effect; by coordinating the drip irrigation area and drip irrigation flow rate, the working height and working width of the sedimentation device are determined, and combined with the design of the working length of the sedimentation device, it can ensure that the treated water can meet the requirements of drip irrigation, and at the same time reduce the floor area of the sedimentation device. Brief Description of the Drawings

[0050] Figure 1 It is a three-dimensional view of the light filtration head system for the Yellow River diversion drip irrigation.

[0051] Figure 2 It is a three-dimensional view of the sedimentation sub-box and the sedimentation funnel installed together.

[0052] Figure 3 It is a three-dimensional view of the light filtration head system for the Yellow River diversion drip irrigation after removing some structures.

[0053] Figure 4 It is a flow chart of the design method of the light filtration head system for the Yellow River diversion drip irrigation.

[0054] Among them, 1. water inlet channel; 2. trash rack device; 3. gate; 4. sedimentation device; 41. modular sedimentation box; 42. sedimentation funnel; 43. sand discharge pipe; 44. funnel support; 45. box support; 5. wet pump room; 6. filtration device; 7. dry pump room. Detailed Embodiment

[0055] The following describes the specific embodiments of the present invention to facilitate those skilled in the art of this technology to understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific embodiments. For those of ordinary skill in the art of this technology, as long as various changes are within the spirit and scope of the present invention defined and determined by the appended claims, these changes are obvious, and all inventions and creations using the concept of the present invention are within the scope of protection.

[0056] As Figure 1 and Figure 3 shown, this solution provides a light filtering head system for the Yellow River diversion drip irrigation, which includes an inlet channel 1, a gate 3 and a trash rack device 2 provided on the inlet channel 1. In this solution, the trash rack device 2 is preferably a rotary trash rack, which uses a rake tooth gap of 3 mm to remove sand and stones with a diameter of more than 3 mm and larger floating objects. The water flow after passing through the trash rack is the initial water source.

[0057] The inlet channel 1 is connected to a sedimentation device 4, and the bottom of the sedimentation device 4 is connected to the surface irrigation system through a slurry pump; specifically, the discharged sediment can be discharged to the sediment discharge plot by means of surface irrigation, and this plot undertakes sediment digestion by means of surface irrigation.

[0058] The sedimentation device 4 is connected to a wet pump chamber 5. The submersible pump in the wet pump chamber 5 is connected to a filtering device 6, and the filtering device 6 is connected to the surface drip irrigation system. The sediment particle size entering the surface drip irrigation system is greater than 125 μm and less than 200 μm to achieve light filtering.

[0059] This solution can meet the requirements of drip irrigation for the Yellow River diversion water through three levels of trash racking, sedimentation and filtration, without the need for a complex filtering system, and can greatly reduce the filtering cost; in this solution, the water for flushing the sediment in the sedimentation box and the sediment settled are input into the irrigation area through surface irrigation, so that the sediment can be utilized, and the water for flushing the sediment enters the irrigation area as irrigation water, saving the cost of dredging.

[0060] As Figure 2 and Figure 3 shown, the sedimentation device 4 includes a plurality of modular sedimentation boxes 41 arranged in a rectangular array. A sedimentation funnel 42 is provided at the bottom of each modular sedimentation box 41. Each sedimentation funnel 42 is connected to a slurry pump through a sediment discharge pipe 43. To improve the stability of the sedimentation funnel 42, a funnel support 44 is also provided at the bottom of the sedimentation funnel 42; a sludge level gauge and an ultrasonic vibrator are provided in the sedimentation funnel 42, and electromagnetic valves are provided on the sediment discharge pipes 43 adjacent to the sedimentation funnel 42; the slurry pump, the submersible pump, the sludge level gauge, the ultrasonic vibrator and the electromagnetic valve are all connected to a controller.

[0061] The irrigation water source enters the modular sedimentation tank 41 through the water inlet channel 1. After entering the tank, the cross-sectional area of the water flow increases and the flow velocity decreases. By using different combinations of modular sedimentation tanks 41, the sedimentation distance of the sediment can be satisfied to achieve the sedimentation effect, and the sediment is concentrated by the bottom sedimentation funnel 42.

[0062] As Figure 3 shown, the light filtration head system for the Yellow River diversion drip irrigation also includes a dry pump chamber 7 for installing a slurry pump. Observation windows are provided at the tops of both the dry pump chamber 7 and the wet pump chamber 5; the filtration device 6 is a centrifugal sieve composite filter, and a tank support 45 is provided outside the modular sedimentation tank 41. Observation windows are provided at the top to observe the operation of the equipment and facilitate equipment maintenance and repair; a water outlet hole is provided on the side wall of the wet pump chamber 5 to export the treated water source from the modular sedimentation tank 41.

[0063] The working principle of the light filtration head system of this solution is as follows: Open the gate 3, and the introduced Yellow River water can remove sand and stones with a diameter of more than 3 mm and larger floating objects through the action of the trash rack device 2; then the initial filtered water source enters multiple modular sedimentation tanks 41 of the sedimentation device 4 for sediment precipitation, and the precipitated water is sent to the filtration device 6 through a submersible pump for filtration. After filtration, it is sent to the drip irrigation system for drip irrigation.

[0064] Each sediment level gauge monitors the sediment situation in the sedimentation funnel 42 where it is located at all times, and sends the monitoring information to the controller. When the sediment information is greater than the preset threshold, the controller opens the solenoid valve, ultrasonic vibrator and slurry pump at the sedimentation funnel 42 where the sediment level gauge is located for sand discharge. The ultrasonic vibrator helps the agglomerated sediment quickly enter the sand discharge pipe 43, and the water for flushing the sediment is sent to the surface irrigation system.

[0065] As Figure 4 shown, this solution also provides a design method for the light filtration head system of the Yellow River diversion drip irrigation, which includes steps S1 to S6.

[0066] In step S1, determine the drip irrigation area, surface irrigation area, designed total diversion flow rate and drip irrigation diversion flow rate based on water-sediment coordination; the expression for calculating the drip irrigation area is:

[0067] K = 1 + Q s1 Tt d

[0068] where, A1 is the designed micro-irrigation area, with the unit of hectare (hm 2 ); η t is the field water utilization coefficient. For drip irrigation, it should not be lower than 0.95, and for micro-sprinkler irrigation and bubbler irrigation, it should not be lower than 0.85; η gis the utilization coefficient of pipeline water, which should not be lower than 0.97; f is the scouring water coefficient, which should be determined according to test data. If there is no test data, the value range should be 0.02 - 0.05; F is the allowable reservoir siltation coefficient, which should be determined according to test data. If there is no test data, the value range should be 0.05 - 0.10; K is the recharge coefficient within the rotation irrigation period; T i is the designed irrigation cycle for the i-th crop, with the unit of day (d); E ci is the designed water consumption intensity for the i-th crop, with the unit of millimeter per day (mm / d); a i is the area proportion of the i-th crop, %; M is the types of irrigated crops; t d is the designed daily water supply hours; T is the designed irrigation cycle.

[0069] The total irrigation area A = A1 + A2, where A2 is designed as 8% of A1; The designed water flow rate Q of surface irrigation s2 The expression is:

[0070]

[0071] Q s = Q s1 + Q s2 , Calculate the designed water flow rate Q of surface irrigation according to A2 s2 and conduct fitting trial calculations with the subsequent scouring water flow rate, and adjust the design parameters according to the calculation results; s0 is the field surface slope, ‰.

[0072] In step S2, according to the dripper size and irrigation cycle of the drip irrigation tape, determine the target particle size when the flow rate attenuation is less than the preset ratio; The target particle size here can be obtained through numerical simulation experiments or experiments can be conducted on the selected drip irrigation tape. Specifically:

[0073] Inject water sources with different sediment particle sizes into the selected drip irrigation tape, operate the irrigation cycle, measure the flow rate attenuation, and select the sediment particle size corresponding to when the flow rate attenuation is less than the preset ratio as the final target particle size.

[0074] In step S3, according to the average working water level depth, determine the working height range of the sedimentation device 4, and based on the working height range, determine the working width range of the sedimentation device 4; The range of the working depth is H ≥ H ω H ω is the average working water level depth, m.

[0075] During implementation, the preferred expression for calculating the working width based on the working height in this solution is:

[0076]

[0077] Among them, B is the working width, m; H is the working height; Qs For the designed total diversion flow rate, m 3 / s; v is the sediment transport velocity; A1 is the drip irrigation area. The sediment transport velocity is equal to the working flow velocity, which is the ratio of the flow rate Q s1 to the micro-irrigation area A1.

[0078] In step S4, according to the working height range and the working width range, the optimal cross-section of the flow is calculated, the working height is determined, and the working width is calculated based on the working height; it should be noted here that the working height of this solution refers to the height of the modular sedimentation tank and does not include the height of the sedimentation funnel.

[0079] In step S5, according to the target particle size, the sediment settling velocity of the sediment is calculated; then, according to the sediment settling velocity and the working height, the settling time is calculated;

[0080] In an embodiment of the present invention, the method for calculating the sediment settling velocity of the sediment according to the target particle size is:

[0081] When the target particle size ≤ 0.062 mm, the expression for calculating the sediment settling velocity is:

[0082]

[0083] where ω is the sediment settling velocity; g is the acceleration due to gravity; ρ s is the sediment density; ρ w is the clear water density; d is the target particle size; v n is the kinematic viscosity of water; t is the water temperature;

[0084] When 0.062 < target particle size ≤ 2.0 mm, the expression for calculating the sediment settling velocity is:

[0085] (lgS a + 3.790) 2 +(lgψ - 5.777) 2 = 39.0

[0086]

[0087] where S a is the settling velocity criterion; ψ is the particle size criterion.

[0088] In step S6, according to the settling time and the sediment transport velocity, the working length of the sedimentation device 4 is calculated:

[0089] L = 1.2vt c

[0090] where L is the working length; t c is the settling time, t c = Hω / ω; v is the sediment transport velocity.

[0091] After obtaining the working width and working length in this solution, the number of modular sedimentation tanks arranged for the working width and working length can be determined according to the length and width of the modular sedimentation tank, and then the total number of modular sedimentation tanks and sedimentation funnels required for the sedimentation device can be obtained.

[0092] During implementation, the preferred design method of the light filtration head system in this solution further includes:

[0093] Calculate the designed sediment content S to be processed according to the target particle size and characteristic particle size D :

[0094]

[0095] where d is the target particle size; d 97 is the characteristic particle size; m is an exponent that varies with the thickness of sediment particles;

[0096] Calculate the designed sediment treatment rate η according to the designed sediment content to be processed L :

[0097]

[0098] where S b is the sediment content of the water source;

[0099] Filter the water passing through the sedimentation device 4 with sieves of different mesh numbers, collect the sediment content of the filtered effluent, and then calculate the sedimentation rate E1:

[0100]

[0101] where Q1 is the effluent flow rate, m 3 / s; S0 is the sediment content of the inlet channel 1, kg / m 3 ; S1 is the sediment content of the effluent, kg / m 3 , Q0 is the total flow rate of the water coming from the channel, m / s;

[0102] Calculate the sedimentation rate E1 closest to the designed sediment treatment rate η among multiple sedimentation rates E1 L and use the sieve corresponding to it as the finally selected sieve of the filtering device 6.

[0103] By selecting the sieve of the filtering device 6 in the above manner in this solution, it can ensure that the sediment content in the output irrigation water is close to the target particle size to ensure the normal irrigation of the subsequent drip irrigation tape.

[0104] During implementation, the preferred design method of the light filtering header system in this solution further includes calculating the sediment discharge time for equal flow velocity sediment discharge according to the dead volume and working width of the sedimentation device 4:

[0105]

[0106] where T ps is the sediment discharge time; γ s is the sediment specific gravity; V s is the dead volume of the sedimentation device 4; ρ c is the sediment content in the scouring water flow; q c is the unit-width scouring discharge; B is the working width.

[0107] This solution can accurately calculate the sediment discharge time through the working width. Then, when the sediment in the sedimentation funnel 42 reaches the set value collected by the sludge level gauge, the solenoid valve is opened to discharge sediment according to the sediment discharge time, so as to discharge the sediment in the sedimentation funnel 42 as much as possible while avoiding excessive water being used for sediment discharge.

[0108] To sum up, this solution inputs the water for flushing the sediment in the sedimentation device 4 and the precipitated sediment into the irrigation area through surface irrigation, without the need to set up a sedimentation tank in the irrigation area, which can solve the problems of large floor area, high construction cost, inconvenient dredging of the existing sedimentation tank, and lack of pertinence in the treatment of the Yellow River water header.

Claims

1. A light filtration head system for the Yellow River diversion drip irrigation, characterized in that, It includes a water inlet channel, a gate and a trash rack arranged on the water inlet channel. The water inlet channel is communicated with a sedimentation device, and the bottom of the sedimentation device is communicated with a ground irrigation system through a slurry pump. The sedimentation device is communicated with a wet pump chamber, and a submersible pump in the wet pump chamber is connected to a filtering device. The filtering device is communicated with a ground drip irrigation system. The sediment particle size entering the ground drip irrigation system is greater than 125μm and less than 200μm to achieve light filtration.

2. The yellow river diversion drip irrigation light filtration head system according to claim 1, characterized in that The sedimentation device includes a plurality of modular sedimentation tanks arranged in a rectangular array. A sedimentation funnel is arranged at the bottom of each modular sedimentation tank, and each sedimentation funnel is communicated with the slurry pump through a sand discharge pipe. A sludge level gauge and an ultrasonic vibrator are arranged in the sedimentation funnel. Solenoid valves are arranged on the sand discharge pipes adjacent to the sedimentation funnel. The slurry pump, the submersible pump, the sludge level gauge, the ultrasonic vibrator and the solenoid valve are all connected to a controller.

3. The yellow river diversion drip irrigation light filtration head system according to claim 1, characterized in that, It further includes a dry pump chamber for arranging the slurry pump. Observation windows are arranged at the tops of the dry pump chamber and the wet pump chamber. The filtering device is a centrifugal screen composite filter, and a box support is arranged outside the modular sedimentation tank.

4. The design method of the head system for light filtration of the Yellow River diversion drip irrigation according to any one of claims 1-3, characterized in that, It includes steps: S1. Determine the drip irrigation area, ground irrigation area, designed total diversion flow rate and drip irrigation diversion flow rate based on water-sediment coordination. S2. Determine the target particle size when the flow rate attenuation is less than a preset ratio according to the drip head size and irrigation period of the drip irrigation tape. S3. Determine the working height range of the sedimentation device according to the average depth of the working water level, and determine the working width range of the sedimentation device based on the working height range. S4. Try to calculate the optimal cross-sectional area of flow according to the working height range and the working width range, determine the working height, and calculate the working width based on the working height. S5. Calculate the sediment settling velocity of the sediment according to the target particle size; then calculate the settling time according to the sediment settling velocity and the working height. S6. Calculate the working length of the sedimentation device according to the settling time and the sediment transport velocity.

5. The design method according to claim 4, characterized in that, The expression for calculating the working width based on the working height is: Among them, B is the working width; H is the working height; Q s is the total designed diversion flow rate; v is the sediment transport velocity; A1 is the drip irrigation area.

6. The design method according to claim 5, characterized in that The expression for calculating the drip irrigation area is: Among them, η t is the field water utilization coefficient; η g is the pipeline water utilization coefficient; f is the scouring water coefficient; F is the allowable reservoir siltation coefficient; K is the multiple storage coefficient within the rotation irrigation period; T i is the designed irrigation cycle for the i-th crop; E ci is the designed water consumption intensity of the i-th crop; a i is the area proportion of the i-th crop; M is the types of irrigated crops; t d is the designed daily water supply hours; T is the designed irrigation cycle.

7. The design method according to claim 4, characterized in that, The method for calculating the sediment settling velocity of the sediment according to the target particle size is: When the target particle size ≤ 0.062mm, the expression for calculating the sediment settling velocity is: Among them, ω is the sediment settling velocity; g is the acceleration of gravity; ρ s is the sediment density; ρ w is the clear water density; d is the target particle size; v n is the kinematic viscosity of water; t is the water temperature; When 0.062 < target particle size ≤ 2.0mm, the expression for calculating the sediment settling velocity is: (lgS a +3.790) 2 +(lgψ - 5.777) 2 =39.0 where S a is the settling velocity criterion number; ψ is the particle size criterion number.

8. The design method according to claim 4, characterized in that The expression for calculating the working length of the sedimentation device is: L = 1.2vt c Among them, L is the working length; t c is the settlement time; v is the sediment transport velocity.

9. The design method according to any one of claims 4-8, characterized in that It further includes: Calculate the designed sediment concentration S to be processed according to the target particle size and characteristic particle size D : where d is the target particle size; d 97 is the characteristic particle size; m is an exponent that varies with the fineness of sediment particles; Treat the sediment concentration according to the design and calculate the designed sediment treatment rate η L : Among them, S b is the sand content in the water source; Filter the water passing through the sedimentation device with sieves of different mesh numbers, collect the sediment content of the filtered effluent, and then calculate the sedimentation rate E1: Wherein, Q1 is the effluent flow rate; S0 is the sediment content of the water inlet channel; S1 is the sediment content of the effluent, and Q0 is the total flow rate of the water coming from the channel; Calculate the sedimentation rate E1 among multiple sedimentation rates E1 that is closest to the designed sediment treatment rate η L and use the corresponding sieve of this sedimentation rate E1 as the sieve finally selected for the filtering device.

10. The design method according to any one of claims 4-8, characterized in that It further includes calculating the sand discharge time for equal flow velocity sand discharge according to the dead volume and working width of the sedimentation device: Among them, T ps is the sediment flushing time; γ s is the sediment specific gravity; V s is the dead volume of the sedimentation device; ρ c is the sediment concentration in the flushing water flow; q c is the unit-width sediment flushing discharge; B is the working width.

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