Water-saving and energy-saving irrigation system and method for realizing uniform irrigation

Abstract

The application discloses a kind of water-saving and energy-saving irrigation system and method for realizing uniform irrigation, the irrigation system includes main control unit, variable frequency water pump, opening adjustable valve and soil moisture sensor, main control unit input end is connected with soil moisture sensor, and main control unit output end is connected with variable frequency water pump and opening adjustable valve.The application realizes the opening and closing of variable frequency water pump and opening adjustable valve in time by real-time monitoring of soil moisture content and comparison with set value, and the speed of variable frequency water pump and the opening of opening adjustable valve, realizes the uniform irrigation of upstream and downstream areas of irrigation system, accurately controls irrigation flow, ensures that the same irrigation area obtains consistent crop water, reduces the waste of irrigation water in local area with excessive water pressure, synchronously reduces the energy consumption of this part of water quantity pumping, and realizes unattended and intelligentization of irrigation system;By main control unit simulation calculation each irrigation point water pressure, flow value, reduce the layout of water pressure and flow sensor, reduce construction investment.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of agricultural irrigation technology, and particularly relates to a water-saving and energy-saving irrigation system and method for realizing uniform irrigation. BACKGROUND

[0002] In the process of large-scale irrigation in large and medium-sized irrigation areas, due to the existence of hydraulic friction and terrain slope, when the water flow is transported from the upstream to the downstream by the pressurized pipeline irrigation, there is often a water pressure difference, and the pressure difference is more significant in long-distance irrigation, which causes the uneven irrigation water in the upstream and downstream of the same irrigation area, the crops in the upstream (or low-lying areas) get more water, and the crops in the downstream (or higher areas) get less water, which affects the normal growth of crops and also causes a large waste of water resources and energy.

[0003] Similarly, in the sub-irrigation areas of large and medium-sized irrigation areas, due to the existence of hydraulic friction and terrain slope, the required irrigation water pressure is different, if the water pump is irrigated according to the same speed and lift, it causes the uneven water in each sub-irrigation area, and also causes a large waste of energy.

[0004] In addition, the opening and closing, speed, opening degree 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 precision is low, and the work efficiency is low.

[0005] Based on this, the present application discloses a water-saving and energy-saving irrigation system and method for realizing uniform irrigation. SUMMARY

[0006] To solve the technical problems existing in the prior art, the purpose of the present application is to provide a water-saving and energy-saving irrigation system and method for realizing uniform irrigation.

[0007] To achieve the above purpose and achieve the above technical effect, the technical solution adopted by the present application is as follows:

[0008] A water-saving and energy-saving irrigation system for realizing uniform irrigation, comprising a master controller, a variable frequency water pump, an opening degree adjustable valve and a soil moisture sensor, the input end of the master controller is connected with the soil moisture sensor, and the output end of the master controller is connected with the variable frequency water pump and the opening degree adjustable valve.

[0009] Further, the variable frequency water pump, the opening degree adjustable valve and the soil moisture sensor are connected with the master controller through a wireless communication transmission unit respectively.

[0010] The present application also discloses a water-saving and energy-saving irrigation method for realizing uniform irrigation, which adopts a water-saving and energy-saving irrigation system for realizing uniform irrigation as described above to carry out irrigation, and the method comprises the following steps:

[0011] 1) Real-time monitoring of soil moisture content data of the planting unit where the soil moisture sensor is located, and transmitting to the host computer through the wireless communication transmission unit;

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

[0013] 3) Determine whether the lowest water pressure in each position point is in the set interval;

[0014] 4) Determine whether the lowest water pressure in the downstream area of each valve is in the set interval;

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

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

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

[0018] Further, in step 2), if the soil moisture content collected by the soil moisture sensor is lower than the set value, the host computer controls the variable frequency water pump of the planting unit to run at rated speed, and controls the opening of the opening adjustable valve of the planting unit to be fully open, while the rest of the planting units are fully closed. Run, hydraulic calculation through continuity equation, energy equation, H-W formula, etc. Head loss formula to simulate system flow, water pressure at each position point;

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

[0020] Further, 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] Where i, j are the numbers of the start and end nodes of the pipe section; q i is the water consumption flow of node i; q ij is the flow of each pipe section associated with node i.

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

[0025] For any pipe section, the difference between the energy at both ends of the pipe section is equal to the energy consumption due to hydraulic friction:

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

[0027] wherein H i , H j are water pressure of pipe segment start and end nodes i, j; h ij is pipe segment pressure drop; s ij is pipe segment friction; q ij is pipe segment flow; and n is an index selected according to water head loss calculation formula.

[0028] Further, the H-W formula is:

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

[0030] wherein c ij is H-W coefficient; d ij is pipe segment diameter; l ij is pipe segment length; and q ij is pipe segment flow, then pipe segment friction s ij and index n can be determined respectively.

[0031] Further, in step 3), if the lowest water pressure in each position point is located in the set interval, then the rotation speed of the variable frequency water pump is recorded;

[0032] if the lowest water pressure in each position point is not located in the set interval, then the rotation speed of the variable frequency water pump is adjusted until the irrigation lowest water pressure is located in the set interval.

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

[0034] if the lowest water pressure in each valve downstream region is not located in the set interval, then the opening of the opening adjustable valve is adjusted until the valve downstream region lowest water pressure is located in the set interval.

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

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

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

[0038] 1) The application discloses a water-saving and energy-saving irrigation system and method for realizing uniform irrigation, which realizes timely regulation and control of the opening and closing of variable frequency water pumps and opening adjustable valves and the rotation speed of the variable frequency water pumps and the opening of the opening adjustable valves by comparing the real-time monitoring of soil water content with a set value, realizes uniform irrigation of upstream and downstream areas of the irrigation system, precise control of irrigation flow, guarantee of consistent water quantity acquisition of crops in the same irrigation area, guarantee of suitable water environment for crops, and realizes unattended and intelligentization of the irrigation system.

[0039] 2) The application discloses a water-saving and energy-saving irrigation system and method for realizing uniform irrigation, which reduces the waste of irrigation water in local areas with excessively high water pressure and simultaneously reduces the pumping energy consumption of the water in the part.

[0040] 3) The application discloses a water-saving and energy-saving irrigation system and method for realizing uniform irrigation, the rotation speed of the variable frequency water pump is adjustable, the rotation speed and lift are adjusted according to the required water pressure of the sub-irrigation area, further energy saving is realized, and different water pressure needs of irrigation areas can be adapted.

[0041] 4) The application discloses a water-saving and energy-saving irrigation system and method for realizing uniform irrigation, the wireless communication transmission unit does not need wiring and is convenient to arrange; the water pressure and flow value of each irrigation point are simulated and calculated by the master controller, the arrangement of water pressure and flow sensors is reduced, and construction investment is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 is a structural schematic diagram of the application;

[0043] Figure 2 is a flowchart of the application;

[0044] Figure 3 is a pipe section flow comparison chart of the opening of the opening adjustable valve of embodiment 1 of the application before and after optimization;

[0045] Figure 4 is a soil water content comparison chart of embodiment 1 of the application. DETAILED DESCRIPTION

[0046] The application will be described in detail below, so that the advantages and features of the application can be more easily understood by those skilled in the art, and the protection scope of the application can be more clearly and explicitly defined.

[0047] The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.

[0048] As shown in Figures 1-4 The application discloses a water-saving and energy-saving irrigation system for realizing uniform irrigation, comprising:

[0049] A variable frequency water pump 1 is used for providing water pressure required for irrigation, and the adjustable rotating speed characteristic thereof can be differentiated to adapt to water pressure requirements of different irrigation areas, so that energy consumption is reduced.

[0050] An irrigation water supply pipeline 2 is determined according to the conveying flow and water pressure of the main pipe 2-1, the stem pipe 2-2 and the branch pipe 2-3.

[0051] An opening adjustable valve 3 is arranged at each branch point or key node of the irrigation water supply pipeline 2, and the adjustable opening characteristic thereof can reduce local excessively high water pressure downstream of the valve as required, so that uniform irrigation of each pipe section is guaranteed, irrigation flow is accurately controlled, water resources are saved, and pumping energy consumption is simultaneously reduced.

[0052] An irrigation terminal 4 is arranged at a branch pipe outflow, and irrigation water quantity supply is realized.

[0053] A soil moisture sensor 5 is arranged.

[0054] A wireless communication transmission unit is arranged.

[0055] A master controller is arranged.

[0056] The variable frequency water pump 1, the opening adjustable valve 3 and the soil moisture sensor 5 are connected to the master controller through the wireless communication transmission unit, respectively, the master controller receives soil water content data collected by the soil moisture sensor 5 and compares the data with a set value, controls opening and closing of the variable frequency water pump 1 and the opening adjustable valve 3 and rotating speed of the variable frequency water pump 1 and opening of the opening adjustable valve 3 according to a comparison result, and finally realizes accurate control of irrigation flow, uniform irrigation of system upstream and downstream areas, reduction of irrigation water loss and electric energy consumption cost of farmers, unattended and intelligentization.

[0057] As shown in Figure 2 The application discloses a water-saving and energy-saving irrigation method for realizing uniform irrigation, comprising the following steps:

[0058] 1) A soil moisture sensor 5 is used for monitoring and collecting soil water content data of a planting unit in real time, and the data are transmitted to a master controller through a wireless communication transmission unit.

[0059] 2) The master 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 collected by the soil moisture sensor 5 is lower than the set value, the master controller controls the variable frequency water pump 1 of the planting unit to run at rated speed, and controls the opening of the opening adjustable valve 3 of the planting unit to be fully open, while the rest of the planting units are fully closed. Hydraulic calculation is carried out by using continuity equation, energy equation, H-W formula, etc. to simulate the flow and water pressure at each position point of the system;

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

[0062] Continuity equation: as the embodiment of mass conservation law 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] Where i, j are the numbers of the start and end nodes of the pipe section; q i is the water flow of node i; q ij is the flow of each pipe section associated with node i. It is generally assumed that the flow out of the node is positive and the flow into the node is negative;

[0065] Energy equation: as the embodiment of energy conservation law in the basic principles of hydraulics, for any pipe section, the difference between the energy at both 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] Where H i , H j are the water pressures of the start and end nodes i, j of the pipe section; h ij is the pressure drop of the pipe section; s ij is the pipe section friction; q ij is the pipe section flow; n is the index selected according to the water head loss calculation formula;

[0068] H-W formula: for the determination of pipe section friction s ij and index n, the H-W formula is taken as an example:

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

[0070] wherein c ij is the H-W coefficient; d ij is the pipe segment diameter; l ij is the pipe segment length; q ij is the pipe segment flow rate. Then s ij and n can be determined respectively;

[0071] 3) determining whether the lowest water pressure in each position point is located in the set interval:

[0072] If yes, the rotating speed of the variable frequency water pump 1 is recorded;

[0073] If no, the rotating speed of the variable frequency water pump 1 is adjusted until the lowest water pressure of irrigation is located in the set interval;

[0074] 4) determining whether the lowest water pressure in the downstream area of each valve is located in the set interval:

[0075] If yes, the opening degree of the opening degree adjustable valve 3 is recorded;

[0076] If no, the opening degree of the opening degree adjustable valve 3 is adjusted until the lowest water pressure in the downstream area of the valve is located in the set interval;

[0077] 5) starting irrigation with the recorded rotating speed of the water pump and the opening degree of the valve;

[0078] 6) determining whether the soil moisture content data collected by the soil moisture sensor 5 is higher than or equal to the set value, if yes, ending irrigation and closing the variable frequency water pump 1 and the opening degree adjustable valve 3, if no, not performing action;

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

[0080] Example 1

[0081] As shown, an irrigation area is selected, 1520 mu, 1000m long and 1000m wide, divided into planting unit one and planting unit two, and the irrigation water pressure is 30m. Figures 1-4 The water-saving and energy-saving irrigation system and method for realizing uniform irrigation are applied to the planting unit one:

[0082]

[0083] ​Set the variable frequency water pump 1 to run at rated speed in the hydraulic simulation software, and set the opening of the opening adjustable valve 3 of the pipe section I 6, pipe section II 7, pipe section III 8, pipe section IV 9 and pipe section V 10 in planting unit one to be the maximum, and the opening adjustable valve of planting unit two is closed, and the hydraulic calculation is carried out through the continuity equation, energy equation, H-H formula and other head loss formulas, and the flow and water pressure of each position point of the system are simulated;

[0084] Determine whether the lowest water pressure in each position point of the planting unit one is located in the set interval: adjust the speed of the variable frequency water pump 1 to 3520r / min, that is, 97.8% of the rated speed 3600r / min, and the lowest water pressure in each position point is 30m, which meets the set interval, and the lowest water pressure is 31.9m when running at rated speed, which causes unnecessary water pressure waste;

[0085] Determine whether the lowest water pressure in each valve downstream area of the planting unit one is located in the set interval: adjust the opening of the opening adjustable valve 3 of the pipe section I 6, pipe section II 7, pipe section III 8, pipe section IV 9 and pipe section V 10 to 99%, 95%, 93%, 92% and 84% respectively, and the lowest water pressure in each valve downstream area is 30m, which meets the set interval, and the irrigation water pressure is 30.07, 30.74, 31.07, 31.30 and 32.69m respectively when the valve is fully opened, which causes uneven water pressure;

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

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

[0088] Irrigation water volume is reduced: considering that the outflow is proportional to the 1.18th power of water pressure, the irrigation water pressures of the pipe section I 6, pipe section II 7, pipe section III 8, pipe section IV 9 and pipe section V 10 are 30.07, 30.74, 31.07, 31.30 and 32.69m respectively under the original water pressure, and the pipe section flow rates are 20.05, 20.58, 20.84, 21.02 and 22.13L / s respectively, and after the valve opening is optimized and adjusted, the irrigation water pressures are all adjusted to 30.00m, and the pipe section flow rates are all adjusted to 20L / s, and the pipe section flow rates are reduced by 0.26%, 2.84%, 4.04%, 4.89% and 9.63% respectively, and the comprehensive flow rate is reduced by 4.43%.

[0089] The irrigation is uniformly distributed: while reducing the irrigation water quantity, the pipe section flow is adjusted to 20 L / s, and the irrigation of the upstream and downstream areas is uniform. Taking single irrigation of 20 mm water quantity and initial soil moisture content of 20% as an example, under the original water pressure state, the soil moisture contents of the pipe section I 6, the pipe section II 7, the pipe section III 8, the pipe section IV 9 and the pipe section V 10 are 21.8%, 22.1%, 22.3%, 22.4% and 23.2% respectively after irrigation, and the moisture content difference between the upstream and downstream can be more than 1%, and repeated irrigation for many times in the whole growth period, the uneven water quantity will affect the crop growth. After the valve opening degree is optimized and adjusted, the soil moisture contents of the pipe section I 6, the pipe section II 7, the pipe section III 8, the pipe section IV 9 and the pipe section V 10 are all adjusted to 21.7%, and the irrigation unevenness under the original state is improved.

[0090] The irrigation energy consumption is reduced: it is reduced by 4.43% in proportion to the flow, and due to the adjustment of the rotating speed (3600 r / min to 3520 r / min), the irrigation energy consumption can be further reduced by 6.52%.

[0091] The parts or structures not specifically described in the present application can adopt the prior art or existing products, and will not be repeated here.

[0092] The above is only an embodiment of the present application, and does not limit the patent range of the present application, and any equivalent structure or equivalent process transformation using the content of the present application specification, or direct or indirect application in other related technical fields, are also included in the patent protection range of the present application.

Claims

1. A water-saving and energy-efficient irrigation method for achieving uniform irrigation, characterized in that, Includes the following steps: 1) The soil moisture content data of the planting unit is collected in real time by the soil moisture sensor and transmitted to the main controller through the wireless communication transmission unit; 2) The main controller receives soil moisture content data collected by the soil moisture sensor and compares it with the set value to determine whether the soil moisture content data collected by the soil moisture sensor is lower than the set value: 3) Determine whether the lowest water pressure at each location point 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 based on the recorded pump speed and valve opening; 6) Determine whether the soil moisture content data collected by the soil moisture sensor is higher than or equal to the set value; 7) Repeat steps 1) through 6). 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 open, while the other planting units are fully closed. Hydraulic calculations are performed through the continuity equation, energy equation, and Heisenberg-Williams formula to simulate the flow rate and water pressure at each location point 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.

2. The water-saving and energy-efficient irrigation method for achieving uniform irrigation according to claim 1, characterized in that, The expression for the continuity equation is: For any hydraulic node i, the algebraic sum of the inflow and outflow from that node is zero: ； Where i and j are the numbers of the start and end nodes of the pipe segment; q i Let q be the water flow rate at node i; ij Let i represent the flow rate of each pipe segment associated with node i.

3. The water-saving and energy-efficient irrigation method for achieving uniform irrigation according to claim 1, characterized in that, The energy equation is expressed as follows: For any given pipe segment, the energy difference between its two ends is equal to the energy consumed by hydraulic friction: ； Among them, H i H j The water pressure at the start and end points i and j of the pipe section; h ij For the pressure drop of the pipe section; s ij For pipe section friction; q ij denoted as , where is the flow rate of the pipe section; n is an index selected based on the head loss calculation formula.

4. The water-saving and energy-efficient irrigation method for achieving uniform irrigation according to claim 1, characterized in that, The Heisenberg-Williams formula is: ； Among them, c ij d is the Hessen-Williams coefficient; ij The diameter of the pipe section; l ij q represents the length of the pipe section. ij For the flow rate of the pipe section, the friction s of the pipe section is... ij The corresponding values ​​can be determined by the exponent n.

5. The water-saving and energy-efficient irrigation method for achieving uniform irrigation according to claim 1, characterized in that, In step 3), if the lowest water pressure at each location point is within the set range, then record the speed of the variable frequency water pump. If the lowest water pressure at each location point is not within the set range, adjust the speed of the variable frequency water pump until the lowest irrigation water pressure is within the set range.

6. The water-saving and energy-efficient irrigation method for achieving uniform irrigation according to claim 1, characterized in that, In step 4), if the lowest water pressure in the downstream area of ​​each valve is within the set range, then record the opening degree of the adjustable valve. If the lowest water pressure in the downstream area of ​​each valve is not within the set range, adjust the opening of the adjustable valve until the lowest water pressure in the downstream area of ​​the valve is within the set range.

7. The water-saving and energy-efficient irrigation method for achieving uniform irrigation according to claim 1, 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, then irrigation is ended and the variable frequency water pump and adjustable valve are turned off. If the soil moisture content data collected by the soil moisture sensor is lower than the set value, no action will be taken.

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