Water and fertilizer online automatic mixing device based on ion selective electrode method

Abstract

The utility model relates to a water and fertilizer online automatic mixing device based on an ion selective electrode method. Comprising a potassium nutrient solution tank, a nitrogen nutrient solution tank, a calcium nutrient solution tank, a dynamic buffer tank, a metering pump, a water suction pump, a fertilizer solution pump and a controller, liquid in the potassium nutrient solution tank, liquid in the nitrogen nutrient solution tank and liquid in the calcium nutrient solution tank are guided into the dynamic buffer tank through metering pumps respectively; external clear water is introduced into the dynamic buffer tank through a water suction pump; liquid in the dynamic buffer tank is guided out through a fertilizer liquid pump; a potassium ion selective electrode, a nitrate ion selective electrode, a calcium ion selective electrode and a first liquid level sensor are arranged in the dynamic buffer tank; the mixed fertilizer liquid containing multiple nutrient elements such as potassium, nitrogen and calcium can be prepared at the same time, the fertilizer mixing efficiency is higher, and meanwhile the actual fertilizer preparation condition is better met. Furthermore, all related ion concentrations in the raw water are considered, so that the water and fertilizer proportioning precision is improved; when the water quality of clear water changes, the high matching precision can still be guaranteed.

Description

Technical Field

[0001] The present application relates to the technical field of fertilization equipment, and in particular to an online automatic water-fertilizer mixing device based on an ion selective electrode method. Background Art

[0002] Excessive use of fertilizers not only causes soil compaction and salinization, but also pollutes water resources through water circulation, causing eutrophication and deterioration of water quality. Therefore, achieving precise management of water and fertilizer and improving water and fertilizer utilization efficiency are crucial to the development of green, efficient and sustainable modern agriculture.

[0003] The integrated water and fertilizer technology integrates irrigation and fertilization, and is an indispensable technology in the development of modern agriculture. The integrated water and fertilizer machine based on this technology has many advantages such as water saving, fertilizer saving, automation, customization, protection of water resources and ecological environment, and is increasingly widely used in the field of agricultural irrigation and fertilization. However, the integrated water and fertilizer machines on the market still have some shortcomings in practical applications. First of all, most integrated water and fertilizer machines use the EC / pH method to detect the concentration of fertilizer solution online. This method can only reflect the total concentration and pH information of the fertilizer solution, and cannot detect the content of each nutrient component in the mixed fertilizer solution. Therefore, only a single component of fertilizer solution can be configured, which is difficult to meet the actual growth needs of crops. In addition, the integrated water and fertilizer machines on the market do not consider that the relevant ions in the clear water will affect the accuracy of the water-fertilizer ratio, and there are differences in the water quality of different water sources. When the water quality of fertilizer matching changes, the ratio accuracy of the traditional integrated water and fertilizer machine will fluctuate. For example, when the conductivity method is used, the content of conductive ions in different water qualities is different, which leads to the same conductivity being measured by adding different amounts of fertilizer to the same amount of water, and the proportion of nutrients in the fertilizer solution will be different. Summary of the invention

[0004] In order to solve or partially solve the problems existing in the related art, the present application provides an online automatic water-fertilizer mixing device based on the ion-selective electrode method, which aims to solve the technical problems that the existing water-fertilizer integrated machine can only be configured with a single-component fertilizer solution and is easily affected by water quality.

[0005] The present application provides an online automatic water-fertilizer mixing device based on an ion selective electrode method, comprising a potassium nutrient solution tank, a nitrogen nutrient solution tank, a calcium nutrient solution tank, a dynamic buffer tank, a metering pump, a water suction pump, a fertilizer solution pump, and a controller;

[0006] The liquids in the potassium nutrient solution tank, the nitrogen nutrient solution tank, and the calcium nutrient solution tank are respectively introduced into the dynamic buffer tank through the metering pumps; the dynamic buffer tank is introduced with external clean water through the water suction pump; the liquid in the dynamic buffer tank is discharged through the fertilizer liquid pump;

[0007] The dynamic buffer tank is provided with a potassium ion selective electrode, a nitrate ion selective electrode, a calcium ion selective electrode and a first liquid level sensor;

[0008] The signal input end of the controller is electrically connected to the potassium ion selective electrode, the nitrate ion selective electrode, the calcium ion selective electrode and the first liquid level sensor, respectively, and the signal output end of the controller is electrically connected to the metering pump, the water suction pump and the fertilizer liquid pump, respectively.

[0009] In some solutions, a Y-type filter is provided on the connection pipe between the water suction pump and external clean water.

[0010] In some schemes, a second liquid level sensor is respectively provided in the potassium nutrient solution tank, the nitrogen nutrient solution tank, and the calcium nutrient solution tank. The second liquid level sensor is connected to the signal input end of the controller, and the signal output end of the controller is also connected to the sound and light alarm.

[0011] In some schemes, a conductivity sensor is respectively provided in the potassium nutrient solution tank, the nitrogen nutrient solution tank, and the calcium nutrient solution tank, and the conductivity sensor is connected to the signal input terminal of the controller.

[0012] In some embodiments, a temperature sensor is further provided in the dynamic buffer tank, and the temperature sensor is connected to the signal input terminal of the controller.

[0013] In some embodiments, a flow meter is provided on the outlet pipe of the fertilizer liquid pump, and the flow meter is connected to the signal input terminal of the controller.

[0014] The technical solution provided by this application may have the following beneficial effects:

[0015] This application realizes online and accurate detection of the content of each nutrient component in the mixed fertilizer solution by using the characteristic that each ion selective electrode only responds to specific ions. Therefore, it is possible to simultaneously configure a mixed fertilizer solution containing multiple nutrient elements such as potassium, nitrogen, and calcium. The mixed fertilizer efficiency is higher and it is more in line with the actual fertilizer allocation situation. In addition, the utility model can dynamically change the proportion of each nutrient component according to the real-time growth needs of crops, and has stronger adaptability. Furthermore, this application takes into account the concentration of each relevant ion in the raw water, thereby improving the accuracy of the water-fertilizer ratio. When the water quality of the clean water changes, this application can still ensure a high ratio accuracy.

[0016] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above and other objects, features and advantages of the present application will become more apparent through a more detailed description of exemplary embodiments of the present application in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments of the present application.

[0018] Figure 1 It is a structural schematic diagram of an online automatic water-fertilizer mixing device shown in an embodiment of the present application;

[0019] Figure 2 is a control block diagram of an online automatic water-fertilizer mixing device shown in an embodiment of the present application;

[0020] Figure 3 It is a fuzzy control block diagram of potassium ion concentration regulation of the water-fertilizer online automatic mixing device shown in the embodiment of the present application;

[0021] Figure 4 It is a control flow chart of the online automatic water-fertilizer mixing device shown in the embodiment of the present application.

[0022] Reference numerals:

[0023] 1. Potassium nutrient solution tank; 2. Nitrogen nutrient solution tank; 3. Calcium nutrient solution tank; 4. Dynamic buffer tank; 5. Metering pump; 6. Water suction pump; 7. Fertilizer liquid pump; 18. Controller; 8. Potassium ion selective electrode; 9. Nitrate ion selective electrode; 10. Calcium ion selective electrode; 11. First liquid level sensor; 12. Y-type filter; 13. Second liquid level sensor; 14. Sound and light alarm; 15. Conductivity sensor; 16. Temperature sensor; 17. Flow meter. DETAILED DESCRIPTION

[0024] The embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although the embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to make the present application more thorough and complete, and to fully convey the scope of the present application to those skilled in the art.

[0025] See also Figure 1-Figure 4The present application provides an online automatic water-fertilizer mixing device based on the ion selective electrode method, including a potassium nutrient solution tank 1, a nitrogen nutrient solution tank 2, a calcium nutrient solution tank 3, a dynamic buffer tank 4, a metering pump 5, a water suction pump 6, a fertilizer liquid pump 7, a controller 18, a metering pump 5, a water suction pump 6, and a fertilizer liquid pump 7; it is arranged on an aluminum stand, and there are four layers on the aluminum stand. The potassium nutrient solution tank 1, the nitrogen nutrient solution tank 2, the calcium nutrient solution tank 3, the metering pump 5, and the water suction pump 6 are placed on the third layer, and the dynamic buffer tank 4 and the fertilizer liquid pump 7 are arranged on the second layer, so that all the equipment are assembled into a whole that is convenient for transportation. Casters are arranged at the bottom of the aluminum stand, and the casters can rotate in any direction and have a locking function to improve the flexibility and adaptability of the device.

[0026] The controller 18 is also connected to a touch screen disposed on the first layer of the aluminum stand, and is used to set fertilization parameter information and monitor the operating status of the device in real time. The relevant parameters can also be pre-set in the controller 18, and this method does not affect the operation of the device.

[0027] The controller 18 adopts STM32 single chip microcomputer, and provides the power required for the normal operation of the touch screen and various sensors through the 24V voltage regulator circuit; the power required for the normal operation of the controller 18 is provided through the 3.3V voltage regulator circuit; the 220V AC power supply is the power required for the normal operation of the water suction pump 6, each metering pump 5, the fertilizer liquid pump 7, and each solenoid valve;

[0028] The potassium nutrient solution tank 1 stores a high-concentration potassium nutrient solution, the nitrogen-potassium nutrient solution tank 1 stores a high-concentration nitrogen nutrient solution, and the calcium nutrient solution tank 3 stores a high-concentration calcium nutrient solution.

[0029] The liquids in the potassium nutrient solution tank 1, the nitrogen nutrient solution tank 2, and the calcium nutrient solution tank 3 are respectively introduced into the dynamic buffer tank 4 through the metering pump 5; the dynamic buffer tank 4 is introduced with external clean water through the water suction pump 6; the liquid in the dynamic buffer tank 4 is discharged through the fertilizer liquid pump 7;

[0030] The dynamic buffer tank 4 is provided with a potassium ion selective electrode 8, a nitrate ion selective electrode 9, a calcium ion selective electrode 10 and a first liquid level sensor 11;

[0031] The signal input end of the controller 18 is electrically connected to the potassium ion selective electrode 8, the nitrate ion selective electrode 9, the calcium ion selective electrode 10 and the first liquid level sensor 11, respectively, and the signal output end of the controller 18 is electrically connected to the metering pump 5, the water suction pump 6 and the fertilizer liquid pump 7, respectively.

[0032] The application process:

[0033] 1. The controller 18 controls the water suction pump 6 to start running and pump clean water into the dynamic buffer tank 4. The first liquid level sensor 11 transmits the liquid level height in the dynamic buffer tank 4 to the controller 18 in real time. When the liquid level height in the dynamic buffer tank 4 reaches the first set height, the controller 18 controls the water suction pump 6 to stop running;

[0034] Second, the controller 18 controls the water suction pump 6 and each metering pump 5 to pump clean water and each nutrient solution into the dynamic buffer tank 4 at a corresponding fixed flow rate for full mixing. The potassium ion selective electrode 8, the nitrate ion selective electrode 9, and the calcium ion selective electrode 10 detect the potassium ions, nitrate ions, and calcium ions in the dynamic buffer tank 4 respectively and transmit them to the controller 18. When the concentration of each related ion in the mixed fertilizer liquid reaches the set value, the controller 18 controls the fertilizer liquid pump 7 to start running, extract the fertilizer liquid configured in the dynamic buffer tank 4, and irrigate the crops through the pipeline, so as to realize the "instant application" of the device;

[0035] 3. The controller 18 compares the set value and the actual detection value of the concentration of each relevant ion in the mixed fertilizer solution, and obtains the deviation (e) of each relevant ion concentration and the change rate of the deviation (ec) of each relevant ion concentration as the input variable of the fuzzy controller 18; the fuzzy controller 18 forms a control signal to act on each metering pump 5 after fuzzy reasoning and fuzzy decision-making, and adjusts the injection amount of each nutrient solution by dynamically changing the pulse frequency of each metering pump 5, so that the concentration of each relevant ion in the mixed fertilizer solution finally reaches the set value.

[0036] 4. When the liquid level of the mixed fertilizer liquid in the dynamic buffer tank 4 reaches the second set height, the controller 18 controls the water suction pump 6 and each metering pump 5 to stop running to prevent the fertilizer liquid from overflowing; the fertilizer liquid pump 7 continues to operate at the rated flow rate to extract the mixed fertilizer liquid in the dynamic buffer tank 4 for irrigation; when the liquid level of the mixed fertilizer liquid in the dynamic buffer tank 4 reaches the first set height, the water suction pump 6 and each metering pump 5 restarts.

[0037] The present application adopts the control strategy of "fixed water and fertilizer", that is, the flow rate of the water suction pump 6 is fixed, and the flow rate of each metering pump 5 is dynamically changed, and the control of the flow rate of each metering pump 5 is independent of each other and does not affect each other; taking the potassium ion concentration control in the mixed fertilizer solution as an example, the potassium ion concentration value in the water-fertilizer mixed solution is selected as the controlled quantity, and the pulse frequency of the potassium nutrient solution metering pump 5 is used as the controlled quantity; a two-dimensional fuzzy controller 18 is designed, and its input is the deviation (e=ry) of the set value (r) of the potassium ion concentration in the water-fertilizer mixed solution and the actual detection value (y) and the change rate ec of the potassium ion concentration deviation, and the output is the pulse frequency (u) of the potassium nutrient solution metering pump 5; the injection amount of the potassium nutrient solution is dynamically changed by changing the pulse frequency of the metering pump 5, so that the potassium ion concentration value in the water-fertilizer mixed solution changes, and finally the potassium ion concentration in the water-fertilizer mixed solution reaches the set value; the control method of the nitrate ion and calcium ion concentration in the mixed fertilizer solution is consistent with the potassium ion concentration control method. The specific fuzzy control rules designed are shown in Table 1.

[0038] Table 1 Fuzzy control rules table

[0039]

[0040] In Table 1: the language value corresponding to the concentration deviation e of the relevant ions (potassium ions, nitrate ions, calcium ions) is {high, okay, low}, which respectively indicates that the current relevant ion concentration value is high, just right, and low; the language value corresponding to the change rate of the relevant ion concentration deviation ec is {negative, none, positive}, which respectively indicates that the current relevant ion concentration value decreases, remains unchanged, and increases; the language value corresponding to the pulse frequency u of the metering pump 5 is {down-fast, down-slow, no-change, up-slow, up-fast}, which respectively indicates that the frequency value decreases rapidly, the frequency value decreases slowly, the frequency value remains unchanged, the frequency value increases slowly, and the frequency value increases rapidly.

[0041] Based on the characteristic that ion-selective electrodes only respond to specific ions, the utility model can realize online and accurate detection of the content of each nutrient component (the concentration of each relevant ion) in the mixed fertilizer solution. Therefore, it is possible to simultaneously configure a mixed fertilizer solution containing multiple nutrient elements such as potassium, nitrogen, and calcium. The mixed fertilizer efficiency is higher and it is more in line with the actual fertilizer distribution situation. In addition, the utility model can dynamically change the proportion of each nutrient component according to the real-time growth needs of the crop, and has stronger adaptability.

[0042] Compared with the integrated water-fertilizer machines on the market, the utility model takes into account that the relevant ions contained in clean water will affect the accuracy of the water-fertilizer ratio. When the device is mixing fertilizer, the concentration of the relevant ions in the clean water is taken into account, thereby improving the accuracy of the water-fertilizer ratio. In addition, there are differences in the water quality of different water sources. When the water source for fertilizer mixing changes, the utility model can still ensure a high ratio accuracy when mixing fertilizer.

[0043] Compared with the traditional offline water-fertilizer integrated machine which requires a huge and bulky fertilizer mixing tank to pre-mix the fertilizer solution, the dynamic buffer tank 4 used in the utility model is compact and highly flexible; the dynamic buffer tank 4 can achieve full mixing of water and various nutrient solutions, and the formed water-fertilizer mixture has higher uniformity, and there will be no local over- or under-fertilization during field fertilization, which is beneficial to the normal growth of crops and more environmentally friendly; each ion-selective electrode is placed in the dynamic buffer tank 4, and compared with the pipeline installation (the fast flow rate of the fertilizer solution leads to inaccurate detection and untimely control), the detection of the concentration of each relevant ion is more accurate; in addition, the utility model can achieve "instant preparation and instant application", that is, the dynamic buffer tank 4 is simultaneously injecting water and various nutrient solutions and extracting the mixed fertilizer solution, and the configured water-fertilizer mixture is directly irrigated to the crops through the pipeline, and the mixing efficiency is higher and the adaptability is stronger, and the application scenarios in modern agriculture are more extensive.

[0044] In some specific embodiments, a Y-type filter Y12 is provided on the connection pipe between the water suction pump 6 and the external clean water, which is used to filter large particles of solid impurities in the raw water, effectively avoiding the problem of pipeline blockage, and at the same time, effectively improving the accuracy of the fertilizer liquid ratio.

[0045] In some specific embodiments, a second liquid level sensor 13 is respectively provided in the potassium nutrient solution tank 1, the nitrogen nutrient solution tank 2, and the calcium nutrient solution tank 3. The second liquid level sensor 13 adopts an XKC-Y28-NO type liquid level sensor, which is used to realize non-contact detection of the height of the nutrient solution in the tank. The second liquid level sensor 13 is connected to the signal input end of the controller 18, and the signal output end of the controller 18 is also connected to the sound and light alarm 14; when the liquid level in the nutrient solution tank is lower than the set liquid level, the controller 18 controls the sound and light alarm 14 to send an alarm signal to remind the user to add nutrient solution in time.

[0046] In some specific embodiments, a conductivity sensor 15 is respectively provided in the potassium nutrient solution tank 1, the nitrogen nutrient solution tank 2, and the calcium nutrient solution tank 3, and the conductivity sensor 15 is connected to the signal input end of the controller 18; the conductivity sensor 15 is used to online detect the conductivity value of the nutrient solution in the tank, and then obtain the true concentration value of the nutrient solution, and transmit it to the controller 18. The controller 18 compares the input conductivity value with the set value. When the conductivity value is lower than the set parameter, it indicates that the nutrient solution in the nutrient solution tank has undergone a qualitative change. The controller 18 controls the sound and light alarm 14 to send an alarm signal to remind the user to replace the corresponding nutrient solution in time.

[0047] In some specific embodiments, a temperature sensor 16 is further provided in the dynamic buffer tank 4, and the temperature sensor 16 is connected to the signal input end of the controller 18. When the controller 18 accurately controls the ratio of each ion concentration in the dynamic buffer tank 4, the data input by the temperature sensor 16 is compensated accordingly to eliminate the influence of temperature on the detected concentration, which is beneficial to improve the accuracy of the ratio of each ion concentration in the fertilizer solution.

[0048] In some specific embodiments, a flow meter 17 is provided on the outlet pipe of the fertilizer liquid pump 7, and the flow meter 17 is connected to the signal input end of the controller 18. The flow meter 17 detects the flow rate of fertilizer discharge in real time and transmits it to the controller 18, thereby obtaining the total amount of fertilizer discharge.

[0049] The embodiments of the present application have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. An automatic online water-fertilizer mixing device based on ion selective electrode method, characterized in that: Including potassium nutrient solution tank, nitrogen nutrient solution tank, calcium nutrient solution tank, dynamic buffer tank, metering pump, water suction pump, fertilizer liquid pump, controller; The liquids in the potassium nutrient solution tank, the nitrogen nutrient solution tank, and the calcium nutrient solution tank are respectively introduced into the dynamic buffer tank through the metering pumps; the dynamic buffer tank is introduced with external clean water through the water suction pump; the liquid in the dynamic buffer tank is discharged through the fertilizer liquid pump; The dynamic buffer tank is provided with a potassium ion selective electrode, a nitrate ion selective electrode, a calcium ion selective electrode and a first liquid level sensor; The signal input end of the controller is electrically connected to the potassium ion selective electrode, the nitrate ion selective electrode, the calcium ion selective electrode and the first liquid level sensor, respectively, and the signal output end of the controller is electrically connected to the metering pump, the water suction pump and the fertilizer liquid pump, respectively.

2. The water-fertilizer online automatic mixing device based on the ion selective electrode method according to claim 1, characterized in that: A Y-type filter is arranged on the connecting pipeline between the water suction pump and external clean water.

3. The water-fertilizer online automatic mixing device based on the ion selective electrode method according to claim 1 is characterized in that: A second liquid level sensor is respectively provided in the potassium nutrient solution tank, the nitrogen nutrient solution tank and the calcium nutrient solution tank. The second liquid level sensor is connected to the signal input end of the controller. The signal output end of the controller is also connected to the sound and light alarm.

4. The water-fertilizer online automatic mixing device based on the ion selective electrode method according to claim 3 is characterized in that: The potassium nutrient solution tank, the nitrogen nutrient solution tank, and the calcium nutrient solution tank are each provided with a conductivity sensor, and the conductivity sensor is connected to the signal input terminal of the controller.

5. The water-fertilizer online automatic mixing device based on the ion selective electrode method according to claim 1 is characterized in that: A temperature sensor is also provided in the dynamic buffer tank, and the temperature sensor is connected to the signal input end of the controller.

6. The water-fertilizer online automatic mixing device based on the ion selective electrode method according to claim 1 is characterized in that: A flow meter is provided on the outlet pipeline of the fertilizer liquid pump, and the flow meter is connected to the signal input end of the controller.

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