Water-saving and energy-saving irrigation system and method capable of achieving uniform irrigation

Abstract

The invention discloses a water-saving and energy-saving irrigation system and method capable of achieving uniform irrigation, the irrigation system comprises a main controller, a variable frequency water pump, an opening adjustable valve and a soil moisture content sensor, the input end of the main controller is connected with the soil moisture content sensor, and the output end of the main controller is connected with the variable frequency water pump and the opening adjustable valve. By monitoring the soil moisture content in real time and comparing the soil moisture content with a set value, opening and closing of the variable-frequency water pump and the opening-degree-adjustable valve, the rotating speed of the variable-frequency water pump and the opening degree of the opening-degree-adjustable valve are regulated and controlled in time, the irrigation water amount of upstream and downstream areas of the irrigation system is uniform, the irrigation flow is accurately controlled, and the irrigation efficiency is improved. It is guaranteed that the water volume of crops in the same irrigation area is consistent, waste of irrigation water volume in the area with too high local water pressure is reduced, pumping energy consumption of the part of water volume is reduced synchronously, and unattended operation and intellectualization of the irrigation system are achieved. Water pressure and flow values of all irrigation points are simulated and calculated through the master controller, arrangement of water pressure and flow sensors is reduced, and construction investment is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of agricultural irrigation, and in particular relates to a water-saving and energy-saving irrigation system and method for achieving uniform irrigation. Background Art

[0002] During large-scale irrigation in medium-sized and large irrigation areas, due to the existence of hydraulic friction and terrain slope, there is often a difference in water pressure when the pressurized pipe irrigation water is transported from upstream to downstream, and the pressure difference is more significant during long-distance irrigation, resulting in uneven irrigation water volume upstream and downstream of the same irrigation area. Crops upstream (or in low-lying areas) receive more water, while crops downstream (or in higher terrain) receive less water. This not only affects the normal growth of crops, but also causes a large waste of water resources and energy.

[0003] Similarly, in the sub-irrigation areas of large and medium-sized irrigation districts, the required irrigation water pressure varies due to hydraulic friction and terrain slope. If the water pumps irrigate at the same speed and lift, the water volume in each sub-irrigation area will be uneven, resulting in a large waste of energy.

[0004] In addition, the switch, speed, opening and other parameters of each water pump and pipeline valve often need to be controlled manually. When the irrigation area is large, the labor cost is high, the control accuracy is low, and the work efficiency is low.

[0005] Based on this, the present invention discloses a water-saving and energy-saving irrigation system and method for achieving uniform irrigation. Summary of the invention

[0006] In order to solve the technical problems existing in the prior art, the object of the present invention is to provide a water-saving and energy-saving irrigation system and method for achieving uniform irrigation.

[0007] In order to achieve the above purpose and the above technical effect, the technical solution adopted by the present invention is:

[0008] A water-saving and energy-saving irrigation system for achieving uniform irrigation comprises a main controller, a variable frequency water pump, an adjustable opening valve and a soil moisture sensor, wherein the main controller input end is connected to the soil moisture sensor, and the main controller output end is connected to the variable frequency water pump and the adjustable opening valve.

[0009] Furthermore, the variable frequency water pump, the valve with adjustable opening and the soil moisture sensor are respectively connected to the main controller via a wireless communication transmission unit.

[0010] The present invention also discloses a water-saving and energy-saving irrigation method for achieving uniform irrigation, which uses the water-saving and energy-saving irrigation system for achieving uniform irrigation as described above for irrigation. The method comprises the following steps:

[0011] 1) The soil moisture sensor is used to monitor and collect the soil moisture data of the planting unit in real time, and transmits it to the main controller through the wireless communication transmission unit;

[0012] 2) The main controller receives the soil moisture data collected by the soil moisture sensor and compares it with the set value to determine whether the soil moisture data collected by the soil moisture sensor is lower than the set value:

[0013] 3) Determine whether the lowest water pressure at each location is within the set range;

[0014] 4) Determine whether the minimum water pressure in the downstream area of ​​each valve is within the set range;

[0015] 5) Start irrigation with the recorded pump speed and valve opening;

[0016] 6) Determine whether the soil moisture data collected by the soil moisture sensor is higher than or equal to the set value;

[0017] 7) Repeat steps 1) to 6).

[0018] Furthermore, in step 2), if the soil moisture content collected by the soil moisture sensor is lower than the set value, the main controller controls the variable frequency water pump of the planting unit to run at the rated speed, and at the same time controls the opening of the adjustable valve of the planting unit to be fully opened, and the remaining planting units to be fully closed, and hydraulic calculations are performed through head loss formulas such as the continuity equation, energy equation, and Hessen-Williams formula to simulate the flow and water pressure at each position of the system;

[0019] If the soil moisture content collected by the soil moisture sensor is higher than or equal to the set value, monitoring will continue.

[0020] Furthermore, the expression of the continuity equation is:

[0021] For any hydraulic node i, the algebraic sum of the flow into and out of the node is zero:

[0022] [q i +Σq ij ] i =0

[0023] Among them, i and j are the numbers of the start and end nodes of the pipe segment; q i is the water consumption flow of node i; q ij is the flow rate of each pipe link associated with node i.

[0024] Furthermore, the expression of the energy equation is:

[0025] For any pipe section, the energy difference between the two ends of the pipe section is equal to the energy consumption caused by hydraulic friction:

[0026] h ij=[H i -H j ]=[s ij q ij n ] ij

[0027] Among them, H i , H j is the water pressure at the start and end nodes i and j of the pipe segment; h ij is the pressure drop of the pipe section; s ij is the friction resistance of the pipe section; ij is the flow rate of the pipe section; n is the index selected according to the head loss calculation formula.

[0028] Furthermore, the Hessen-William formula is:

[0029] h ij =10.67c ij -1.852 d ij -4.87 l ij q ij 1.852

[0030] Among them, c ij is the Hessen-William coefficient; d ij is the diameter of the pipe section; l ij is the length of the pipe section; q ij is the flow rate of the pipe section, then the friction resistance of the pipe section s ij The corresponding values ​​can be determined respectively with the index n.

[0031] Furthermore, in step 3), if the lowest water pressure at each position point is within the set interval, the speed of the variable frequency water pump is recorded;

[0032] If the lowest water pressure at each location point is not within the set range, the speed of the variable frequency water pump is adjusted until the lowest irrigation water pressure is within the set range.

[0033] Further, in step 4), if the lowest water pressure in the downstream area of ​​each valve is within the set interval, the opening of the adjustable valve is recorded;

[0034] If the lowest water pressure in the downstream area of ​​each valve is not within the set range, the opening of the adjustable valve is adjusted until the lowest water pressure in the downstream area of ​​the valve is within the set range.

[0035] Furthermore, in step 6), if the soil moisture content data collected by the soil moisture sensor is higher than or equal to the set value, the irrigation is terminated, and the variable frequency water pump and the adjustable opening valve are closed;

[0036] If the soil moisture data collected by the soil moisture sensor is lower than the set value, no action is performed.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] 1) The present invention discloses a water-saving and energy-saving irrigation system and method for achieving uniform irrigation. By real-time monitoring of soil moisture content and comparing it with a set value, timely regulation of the frequency conversion water pump, the opening and closing of the adjustable valve, the speed of the frequency conversion water pump, and the opening of the adjustable valve are achieved, so as to achieve uniform irrigation water volume in the upstream and downstream areas of the irrigation system, accurately control the irrigation flow, ensure that crops in the same irrigation area obtain consistent water volume, ensure a suitable moisture environment for crops, and realize unmanned and intelligent irrigation system;

[0039] 2) The present invention discloses a water-saving and energy-saving irrigation system and method for achieving uniform irrigation, which reduces the waste of irrigation water in areas with excessively high local water pressure while achieving uniform irrigation and simultaneously reduces the energy consumption of pumping this part of water;

[0040] 3) The present invention discloses a water-saving and energy-saving irrigation system and method for achieving uniform irrigation. The speed of the variable frequency water pump can be adjusted, and the speed and head are adjusted according to the required water pressure of the sub-irrigation area, so as to further achieve energy saving and adapt to the water pressure requirements of different irrigation areas;

[0041] 4) The present invention discloses a water-saving and energy-saving irrigation system and method for achieving uniform irrigation. The wireless communication transmission unit does not require wiring and is easy to deploy. The main controller simulates and calculates the water pressure and flow value of each irrigation point, thereby reducing the deployment of water pressure and flow sensors and reducing construction investment. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a structural schematic diagram of the present invention;

[0043] Figure 2 is a flow chart of the present invention;

[0044] Figure 3 This is a flow comparison diagram of a pipe section before and after the opening of the adjustable opening valve of Example 1 of the present invention is optimized;

[0045] Figure 4 It is a comparison diagram of soil moisture content in Example 1 of the present invention. DETAILED DESCRIPTION

[0046] The present invention is described in detail below so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0047] A brief summary of one or more aspects is given below to provide a basic understanding of these aspects. This summary is not an exhaustive overview of all conceived aspects, and is neither intended to identify the key or critical elements of all aspects nor to define the scope of any or all aspects. Its only purpose is to give some concepts of one or more aspects in a simplified form as a prelude to a more detailed description that will be given later.

[0048] like Figure 1-4 As shown, the present invention discloses a water-saving and energy-saving irrigation system for achieving uniform irrigation, comprising:

[0049] The variable frequency water pump 1 is used to provide the water pressure required for irrigation. Its adjustable speed can be differentiated to adapt to the water pressure requirements of different irrigation areas, thereby reducing energy consumption;

[0050] The diameter and material of the irrigation water distribution pipeline 2 are determined according to the delivery flow and water pressure of the main pipe 2-1, the trunk pipe 2-2 and the branch pipe 2-3;

[0051] The valve 3 with adjustable opening is arranged at each bifurcation point or key node of the irrigation water distribution pipeline 2. Its adjustable opening characteristic can reduce the excessive water pressure in the downstream of the valve as needed, ensure uniform irrigation of each pipe section, accurately control the irrigation flow, save water resources and reduce pumping energy consumption at the same time;

[0052] Irrigation terminal 4 is arranged at the outflow of the branch pipe to realize the terminal irrigation water distribution;

[0053] Soil moisture sensor 5;

[0054] A wireless communication transmission unit;

[0055] Master controller;

[0056] Among them, the variable frequency water pump 1, the adjustable opening valve 3 and the soil moisture sensor 5 are respectively connected to the main controller through the wireless communication transmission unit. The main controller receives the soil moisture data collected by the soil moisture sensor 5 and compares it with the set value, and controls the opening and closing of the variable frequency water pump 1 and the adjustable opening valve 3 as well as the speed of the variable frequency water pump 1 and the opening of the adjustable opening valve 3 according to the comparison result, so as to finally realize the precise control of irrigation flow, uniform irrigation water volume in the upstream and downstream areas of the system, reduce the irrigation water loss and electricity energy consumption of farmers, and achieve unmanned operation and intelligence.

[0057] like Figure 2 As shown, the present invention discloses a water-saving and energy-saving irrigation method for achieving uniform irrigation, comprising the following steps:

[0058] 1) The soil moisture sensor 5 is used to monitor and collect the soil moisture data of the planting unit in real time, and transmits the data to the main controller through the wireless communication transmission unit;

[0059] 2) The main controller receives the soil moisture data collected by the soil moisture sensor 5 and compares it with the set value to determine whether the soil moisture data collected by the soil moisture sensor 5 is lower than the set value:

[0060] If the soil moisture content collected by the soil moisture sensor 5 is lower than the set value, the main controller controls the variable frequency water pump 1 of the planting unit to run at the rated speed, and at the same time controls the opening of the adjustable valve 3 of the planting unit to be fully opened, and the remaining planting units to be fully closed, and hydraulic calculations are performed through the continuity equation, energy equation, Hessen-Williams formula and other head loss formulas to simulate the flow and water pressure at each position of the system;

[0061] If the soil moisture content collected by the soil moisture sensor 5 is higher than or equal to the set value, continue monitoring;

[0062] Continuity equation: As the embodiment of the law of conservation of mass in the basic principles of hydraulics, for any hydraulic node i, the algebraic sum of the flow into and out of the node is zero:

[0063] [q i +Σq ij ] i =0

[0064] Among them, i and j are the numbers of the start and end nodes of the pipe segment; q i is the water consumption flow of node i; q ij is the flow rate of each pipe section associated with node i. It is generally assumed that the flow rate out of the node is positive and the flow rate into the node is negative;

[0065] Energy equation: As the embodiment of the law of conservation of energy in the basic principles of hydraulics, for any pipe section, the energy difference between the two ends of the pipe section is equal to the energy consumption caused by hydraulic friction:

[0066] h ij =[H i -H j ]=[s ij q ij n ] ij

[0067] Among them, H i , H j is the water pressure at the start and end nodes i and j of the pipe section; h ij is the pressure drop of the pipe section; s ij is the friction resistance of the pipe section; ij is the flow rate of the pipe section; n is the index selected according to the head loss calculation formula;

[0068] Hessen-William formula: about pipe friction s ij The determination of the exponent n is shown in the Hessen-Williams formula:

[0069] h ij =10.67c ij -1.852 d ij -4.87 l ij q ij 1.852

[0070] Among them, c ij is the Hessen-William coefficient; d ij is the diameter of the pipe section; l ij is the length of the pipe section; q ij is the flow rate of the pipe section. Then s ij and n can be determined respectively;

[0071] 3) Determine whether the lowest water pressure at each location is within the set range:

[0072] If yes, then record the speed of variable frequency water pump 1;

[0073] If not, adjust the speed of the variable frequency water pump 1 until the minimum irrigation water pressure is within the set range;

[0074] 4) Determine whether the minimum water pressure in the downstream area of ​​each valve is within the set range:

[0075] If yes, then record the opening of the adjustable valve 3;

[0076] If not, adjust the opening of the adjustable valve 3 until the lowest water pressure in the downstream area of ​​the valve is within the set range;

[0077] 5) Start irrigation with the recorded pump speed and valve opening;

[0078] 6) Determine whether the soil moisture content data collected by the soil moisture sensor 5 is higher than or equal to the set value. If so, end the irrigation and close the variable frequency water pump 1 and the adjustable opening valve 3. If not, do not perform any action;

[0079] 7) Repeat steps 1) to 6).

[0080] Example 1

[0081] like Figure 1-4 As shown, an irrigation area of ​​1520 mu was selected, with a length and width of about 1000m respectively, divided into planting unit one and planting unit two, and the irrigation water pressure was 30m.

[0082] Applying the water-saving and energy-saving irrigation system and method for achieving uniform irrigation to planting unit 1:

[0083] In the hydraulic simulation software, the variable frequency water pump 1 is set to run at the rated speed, and the opening of the adjustable valve 3 of pipe section Ⅰ6, pipe section Ⅱ7, pipe section Ⅲ8, pipe section Ⅳ9, and pipe section Ⅴ10 in the planting unit 1 is set to the maximum, and the adjustable valve of the planting unit 2 is fully closed. Hydraulic calculations are performed through head loss formulas such as the continuity equation, energy equation, and Hessen-Williams formula to simulate the flow and water pressure at each position of the system;

[0084] Determine whether the lowest water pressure at each position point of the planting unit 1 is within the set range: when the speed of the variable frequency water pump 1 is adjusted to 3520r / min, that is, 97.8% of the rated speed of 3600r / min, the lowest water pressure at each position point is 30m, which is in line with the set range, while the lowest water pressure is 31.9m when running at the rated speed, which results in unnecessary waste of water pressure;

[0085] Determine whether the lowest water pressure in the downstream area of ​​each valve in the planting unit 1 is within the set range: when the opening of the adjustable valve 3 of pipe section Ⅰ6, pipe section Ⅱ7, pipe section Ⅲ8, pipe section Ⅳ9, and pipe section Ⅴ10 is adjusted to 99%, 95%, 93%, 92%, and 84% respectively, the lowest water pressure in the downstream area of ​​each valve is 30m, which is in line with the set range. When the valve is fully open, the irrigation water pressure is 30.07, 30.74, 31.07, 31.30, and 32.69m respectively, and there is uneven water pressure;

[0086] Start irrigation with the recorded pump speed and valve opening.

[0087] By adopting this embodiment, the following can be achieved:

[0088] Reduction of irrigation water volume: considering that the outflow flow rate is proportional to 1.18 times of the water pressure, the irrigation water pressures of sections Ⅰ6, Ⅱ7, Ⅲ8, Ⅳ9 and Ⅴ10 under the original water pressure state were 30.07, 30.74, 31.07, 31.30 and 32.69 m, respectively, and the section flows were 20.05, 20.58, 20.84, 21.02 and 22.13 L / s, respectively. After the valve opening was optimized and adjusted, the irrigation water pressure was adjusted to 30.00 m, and the section flows were adjusted to 20 L / s. The section flows were reduced by 0.26%, 2.84%, 4.04%, 4.89% and 9.63%, respectively, and the comprehensive flow was reduced by 4.43%.

[0089] Uniform irrigation distribution: While reducing the amount of irrigation water, the flow rate of the pipe section is adjusted to 20L / s to achieve uniform irrigation in the upstream and downstream areas. Taking a single irrigation of 20mm water volume and an initial soil moisture content of 20% as an example, under the original water pressure state, the soil moisture content of pipe section Ⅰ6, pipe section Ⅱ7, pipe section Ⅲ8, pipe section Ⅳ9, and pipe section Ⅴ10 after irrigation is 21.8%, 22.1%, 22.3%, 22.4%, and 23.2% respectively. The difference in upstream and downstream moisture content can be more than 1%. Repeated irrigation throughout the growth cycle will affect crop growth due to uneven water volume. After the valve opening is optimized and adjusted, the soil moisture content of pipe section Ⅰ6, pipe section Ⅱ7, pipe section Ⅲ8, pipe section Ⅳ9, and pipe section Ⅴ10 is adjusted to 21.7%. The present invention will improve the uneven irrigation situation in the original state.

[0090] Irrigation energy consumption reduction: It decreases in proportion to the flow rate, i.e. 4.43%. At the same time, due to the adjustment of the rotation speed (3600r / min to 3520r / min), the irrigation energy consumption can be further reduced by 6.52%.

[0091] Parts or structures not specifically described in the present invention may adopt existing technologies or existing products and will not be described in detail here.

[0092] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A water-saving and energy-saving irrigation system for achieving uniform irrigation, characterized in that: It comprises a main controller, a variable frequency water pump, an adjustable opening valve and a soil moisture sensor. The input end of the main controller is connected to the soil moisture sensor, and the output end of the main controller is connected to the variable frequency water pump and the adjustable opening valve.

2. A water-saving and energy-saving irrigation system for achieving uniform irrigation according to claim 1, characterized in that: The variable frequency water pump, the valve with adjustable opening and the soil moisture sensor are respectively connected to the main controller via wireless communication transmission units.

3. A water-saving and energy-saving irrigation method for achieving uniform irrigation, characterized in that: Irrigation is performed using a water-saving and energy-saving irrigation system for achieving uniform irrigation as described in claim 1 or 2, the method comprising the following steps: 1) The soil moisture sensor is used to monitor and collect the soil moisture data of the planting unit in real time, and transmits it to the main controller through the wireless communication transmission unit; 2) The main controller receives the soil moisture data collected by the soil moisture sensor and compares it with the set value to determine whether the soil moisture data collected by the soil moisture sensor is lower than the set value: 3) Determine whether the lowest water pressure at each location is within the set range; 4) Determine whether the minimum water pressure in the downstream area of ​​each valve is within the set range; 5) Start irrigation with the recorded pump speed and valve opening; 6) Determine whether the soil moisture data collected by the soil moisture sensor is higher than or equal to the set value; 7) Repeat steps 1) to 6).

4. A water-saving and energy-saving irrigation method for achieving uniform irrigation according to claim 3, characterized in that: In step 2), if the soil moisture content collected by the soil moisture sensor is lower than the set value, the main controller controls the variable frequency water pump of the planting unit to run at the rated speed, and at the same time controls the opening of the adjustable valve of the planting unit to be fully opened, and the remaining planting units to be fully closed, and hydraulic calculations are performed through head loss formulas such as the continuity equation, energy equation, and Hessen-Williams formula to simulate the flow and water pressure at each position of the system; If the soil moisture content collected by the soil moisture sensor is higher than or equal to the set value, monitoring will continue.

5. A water-saving and energy-saving irrigation method for achieving uniform irrigation according to claim 4, characterized in that: The continuity equation is expressed as: For any hydraulic node i, the algebraic sum of the flow into and out of the node is zero: [q i +Σq ij ] i =0 Among them, i and j are the numbers of the start and end nodes of the pipe segment; q i is the water consumption flow of node i; q ij is the flow rate of each pipe link associated with node i.

6. The water-saving and energy-saving irrigation method for achieving uniform irrigation according to claim 4, characterized in that: The energy equation can be expressed as: For any pipe section, the energy difference between the two ends of the pipe section is equal to the energy consumption caused by hydraulic friction: h ij =[H i -H j ]=[s ij q ij n ] ij Among them, H i , H j is the water pressure at the start and end nodes i and j of the pipe segment; h ij is the pressure drop of the pipe section; s ij is the friction resistance of the pipe section; ij is the flow rate of the pipe section; n is the index selected according to the head loss calculation formula.

7. The water-saving and energy-saving irrigation method for achieving uniform irrigation according to claim 4, characterized in that: The Hessen-William formula is: h ij =10.67c ij -1.852 d ij -4.87 l ij q ij 1.852 Among them, c ij is the Hessen-William coefficient; d ij is the diameter of the pipe section; l ij is the length of the pipe section; q ij is the flow rate of the pipe section, then the friction resistance of the pipe section s ij And the index n can be determined respectively.

8. The water-saving and energy-saving irrigation method for achieving uniform irrigation according to claim 3, characterized in that: In step 3), if the lowest water pressure at each position point is within the set interval, the speed of the variable frequency water pump is recorded; If the lowest water pressure at each location point is not within the set range, the speed of the variable frequency water pump is adjusted until the lowest irrigation water pressure is within the set range.

9. The water-saving and energy-saving irrigation method for achieving uniform irrigation according to claim 3, characterized in that: In step 4), if the lowest water pressure in the downstream area of ​​each valve is within the set interval, the opening of the adjustable valve is recorded; If the lowest water pressure in the downstream area of ​​each valve is not within the set range, the opening of the adjustable valve is adjusted until the lowest water pressure in the downstream area of ​​the valve is within the set range.

10. The water-saving and energy-saving irrigation method for achieving uniform irrigation according to claim 3, characterized in that: In step 6), if the soil moisture content data collected by the soil moisture sensor is higher than or equal to the set value, the irrigation is terminated, and the variable frequency water pump and the adjustable opening valve are closed; If the soil moisture data collected by the soil moisture sensor is lower than the set value, no action is performed.

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