Water and fertilizer integrated device based on multi-cylinder piston pump and water and fertilizer mixing and injection method

Abstract

The application relates to a water and fertilizer integrated device and method based on a multi-cylinder plunger pump. The device comprises a pump body, a power driving unit, a transmission mechanism and a hydraulic end; the hydraulic end comprises fertilizer liquid cylinders and clean water cylinders, each cylinder is provided with a one-way valve. The transmission mechanism drives the reciprocating motion of the plunger through a crankshaft, and the volume ratio of the fertilizer liquid and the clean water is locked to a preset ratio by a mechanical structure. All the discharge valve outlets are connected to a shared water outlet chamber, and the forced mixing and pumping are realized. The scheme has the advantages of reducing redundancy, improving mixing uniformity, response speed and integration.

Description

Technical Field

[0001] This application relates to the field of integrated water and fertilizer technology, and more specifically, to an integrated water and fertilizer device based on a multi-cylinder plunger pump and a method for water and fertilizer mixing and injection. Background Technology

[0002] As a core component of precision management in modern agriculture, fertigation technology, by mixing irrigation water and soluble fertilizers according to crop needs and delivering them directly to the root zone, is of great significance for improving resource utilization efficiency. However, existing systems face significant bottlenecks in practical applications.

[0003] Premixed systems rely on external mixing containers for water and fertilizer mixing. Their structure includes independent mixing tanks, stirring devices, and booster pumps, resulting in redundant equipment and a large footprint. Since the mixing process takes place in atmospheric or low-pressure containers, changes in concentration require a long transmission path to be reflected at the irrigation end when adjusting the fertilizer solution ratio, causing significant response lag and failing to meet the real-time control requirements of variable-rate fertilization. Simultaneously, the liquid in the mixing tank easily forms vertical stratification due to density differences, making it difficult to completely eliminate concentration gradients during stirring, resulting in poor uniformity of the output fertilizer solution and affecting crop absorption. While injection systems use a main pump to deliver clean water and a dedicated fertilizer injection pump to inject concentrated fertilizer solution, mixing relies entirely on natural turbulence within the main pipeline or a post-static mixer. Under low flow or fluctuating flow conditions, the pipeline flow tends towards laminar flow, significantly reducing the diffusion efficiency of fertilizer solution and clean water, leading to uneven mixing. Furthermore, the performance of static mixers is limited by installation location and flow velocity distribution, making them unsuitable for all operating conditions. In addition, the system still requires a separate fertilizer storage unit, and the water and fertilizer supply and mixing functions are not effectively integrated, resulting in a loose system structure and complex maintenance.

[0004] Although plunger pumps offer stable flow rates and minimal pressure-dependent displacement in metering applications, and theoretically can achieve simultaneous multi-media delivery through differentiated multi-cylinder designs, current technology has not yet applied these principles to the field of fertigation. There is a lack of innovative solutions that highly integrate fertilizer and water intake, high-pressure instantaneous mixing, and pressurized injection processes into a single pump body. Therefore, issues such as equipment redundancy, response delays, unstable mixing quality, and low functional integration have long constrained the improvement of the efficiency of integrated fertigation technology. Summary of the Invention

[0006] The purpose of this application is to provide a water and fertilizer integrated device and a water and fertilizer mixing and injection method based on a multi-cylinder plunger pump, which has the advantages of reducing equipment redundancy, improving mixing uniformity, improving response speed, and highly integrated functions.

[0007] This application provides a water and fertilizer integration device based on a multi-cylinder plunger pump, the technical solution of which is as follows:

[0008] A water and fertilizer integration device based on a multi-cylinder plunger pump includes:

[0009] Pump body, power drive unit, transmission mechanism and hydraulic end;

[0010] The hydraulic end includes at least one fertilizer tank and at least two clean water tanks. Each pump cylinder unit is equipped with an independent suction check valve and discharge check valve.

[0011] The transmission mechanism includes a crankshaft driven by a power drive unit, and connecting rods that connect the crankshaft to the plungers in each pump cylinder unit. The crankshaft synchronously drives the plungers of each cylinder to reciprocate. The ratio of the total volume of fluid sucked in and discharged by the fertilizer cylinder and all the clear water cylinders in each reciprocating motion is locked to a preset ratio by the transmission mechanism and / or the mechanical structure of the hydraulic end.

[0012] All discharge check valve outlets are connected to a common outlet chamber integrated inside the pump body. The common outlet chamber is directly connected to the pump body's discharge port, so that the high-pressure fertilizer solution from each cylinder and clean water are forcibly mixed in the common outlet chamber before being pumped out.

[0013] Furthermore, this application also proposes that the crank eccentricity r1 of the connecting rod connected to the plunger of the fertilizer cylinder and the crank eccentricity r2 of the connecting rod connected to the plunger of the clear water cylinder on the crankshaft of the transmission mechanism are different, so that the plunger stroke of the fertilizer cylinder and all clear water cylinders are different, thereby achieving a preset ratio.

[0014] Furthermore, this application also proposes that the eccentricities r1 and r2 satisfy the following relationship:

[0015] n·A_w·r2 : A_f·r1 ≈ M : 1

[0016] In the formula:

[0017] n is the number of water tanks.

[0018] A_w is the cross-sectional area of ​​the plunger in a single clear water tank.

[0019] A_f is the cross-sectional area of ​​the plunger in a single fertilizer cylinder.

[0020] M is the preset mixing ratio of clean water and fertilizer solution.

[0021] Furthermore, this application also proposes that the power drive unit is a variable frequency motor, and the speed is adjusted by an external frequency converter to achieve stepless adjustment of the total output flow while maintaining a preset ratio.

[0022] Furthermore, this application also proposes that the common outlet chamber is equipped with guide ribs, baffles or asymmetric flow channel structures to guide the fertilizer jet and the clear water jet to collide and shear, thereby enhancing the turbulent mixing effect.

[0023] Furthermore, this application also proposes that it includes a pressure sensor, a conductivity sensor, a central controller, and a fertilizer supply control valve; the central controller is used to adjust the rotation speed of the power drive unit and / or the opening degree of the fertilizer supply control valve based on the monitoring data of the pressure sensor and / or the conductivity sensor, so as to achieve closed-loop precise control of the output flow rate and mixing ratio.

[0024] Furthermore, this application also proposes that the fertilizer supply control valve be installed on the suction pipe of the fertilizer cylinder; or, the device further includes a bypass pipe connected between the outlet of the discharge check valve of the fertilizer cylinder and the suction side, and the fertilizer supply control valve is connected in series on the bypass pipe.

[0025] Furthermore, this application also proposes that the ratio of the total fluid volume of the fertilizer tank to all the clear water tanks is set to be adjusted by replacing crankshafts with different combinations of eccentricity, or replacing cylinder liners with different cylinder diameters, or changing the number configuration of fertilizer tanks and clear water tanks, so as to achieve switching of different preset ratios.

[0026] Furthermore, this application also proposes a method for mixing and injecting water and fertilizer using the above-mentioned device, comprising the following steps:

[0027] Connect the suction pipe of the fertilizer tank to the fertilizer source, connect the suction pipe of the clean water tank to the clean water source, and connect the outlet to the irrigation network.

[0028] Start the power drive unit to drive the crankshaft to rotate, which in turn drives each plunger to reciprocate through the connecting rod, and quantitatively draws in and pressurizes out fertilizer liquid and clean water according to a preset ratio;

[0029] The pressurized fertilizer solution and clean water enter the shared water outlet chamber in the form of a high-speed jet, where forced turbulent mixing occurs to form a uniform water-fertilizer solution.

[0030] The mixed water and fertilizer solution is continuously pumped into the irrigation network through the outlet; during this process, the total output flow rate is adjusted by regulating the speed of the power drive unit, while the preset ratio remains unchanged by the mechanical structure.

[0031] Furthermore, this application also proposes to include: real-time monitoring of the pressure and conductivity of the mixed liquid through a closed-loop control system, and adjusting the rotation speed of the power drive unit and / or the opening degree of the fertilizer supply control valve set on the fertilizer inlet pipe or bypass pipe based on the monitoring value feedback, so as to achieve closed-loop precise control of fertilizer application amount and mixing ratio.

[0032] As can be seen from the above, the water and fertilizer integrated device and water and fertilizer mixing and injection method based on a multi-cylinder plunger pump provided in this application solves the problems of equipment redundancy, response delay and unstable mixing quality by integrating fertilizer suction, water suction and high-pressure mixing into a single pump body, locking the ratio and forcing mixing. It has the advantages of reducing equipment redundancy, improving mixing uniformity, improving response speed and highly integrated functions. Attached Figure Description

[0033] Figure 1 A schematic diagram of a water and fertilizer integration device based on a multi-cylinder plunger pump provided in this application.

[0034] Figure 2 This is a three-dimensional schematic diagram of an integrated water and fertilizer device based on a multi-cylinder plunger pump, provided for this application.

[0035] Figure 3 This is a schematic diagram of the cylinder liner for the combination of the fertilizer tank and the clear water tank.

[0036] Figure 4 This is an internal schematic diagram of a shared water outlet chamber provided in this application. Detailed Implementation

[0037] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of this application, and not all embodiments. The components of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0038] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this application, terms such as "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0039] Traditional fertigation systems, whether premixed or injection-based, suffer from problems such as complex equipment structure, large footprint, slow response speed, poor mixing uniformity, limited functionality, and low integration. Premixed systems are prone to concentration stratification and response lag, while injection-based systems are affected by pipeline flow patterns, and the water and fertilizer supply and mixing functions are not highly integrated.

[0040] Example 1:

[0041] like Figures 1-4 As shown, this application proposes an integrated water and fertilizer device based on a multi-cylinder plunger pump. This device highly integrates the pump body 3, power drive unit 1, transmission mechanism, and hydraulic end. The hydraulic end includes at least one fertilizer cylinder 4 and at least two clean water cylinders 5. Each pump cylinder unit is equipped with an independent suction check valve 8 and discharge check valve 9. The crankshaft 18 of the transmission mechanism synchronously drives the plungers 6 of each cylinder to reciprocate, and the preset volume ratio of fertilizer solution to clean water is locked by the transmission mechanism and / or the mechanical structure of the hydraulic end. The outlets of all discharge check valves 9 are connected to a common outlet chamber 14 inside the pump body 3, where high-pressure fertilizer solution and clean water are forcibly mixed, thus overcoming the shortcomings of existing technologies such as equipment redundancy, uneven mixing, lag response, and low integration.

[0042] For ease of understanding, the following explains some key terms in this embodiment:

[0043] Pump body 3: The main structure of the device, used to house and support internal components and provide external connection interfaces.

[0044] Power drive unit 1: Provides mechanical power to the device and drives the transmission mechanism.

[0045] Transmission mechanism: A mechanical component that connects the power drive unit 1 and the hydraulic end plunger 6, converting the rotational motion into the reciprocating linear motion of the plunger 6.

[0046] Hydraulic end: The component in the device that directly contacts the fluid and performs suction, discharge and pressurization operations, including fertilizer tank 4 and clean water tank 5.

[0047] Fertilizer tank 4 and clean water tank 5: The core components of the hydraulic system, used for sucking in and discharging fertilizer solution and clean water respectively.

[0048] Intake check valve 8 and discharge check valve 9: Valves installed on the intake and discharge sides of each pump cylinder unit to ensure unidirectional fluid flow.

[0049] Crankshaft 18: A key component in the transmission mechanism, driven to rotate by the power drive unit 1, and connected to each plunger 6 via connecting rod 10.

[0050] Common outlet chamber 14: A chamber integrated inside the pump body 3, to which all outlets of the discharge check valves 9 are connected, and is the place where fertilizer solution and clean water are forcibly mixed.

[0051] Preset ratio: The ratio of the total volume of fluid drawn in and discharged by the fertilizer tank 4 to all the clear water tanks 5 in each reciprocating motion is locked by the mechanical structure.

[0052] This embodiment provides a water and fertilizer integration device based on a multi-cylinder plunger pump. The overall structure of the device includes a pump body 3, a power drive unit 1, a transmission mechanism, and a hydraulic end. The pump body 3, as the load-bearing structure of the device, can be made of materials such as cast iron or stainless steel to provide sufficient strength and corrosion resistance. Internally, it houses the fertilizer tank 4, the clear water tank 5, the common outlet chamber 14, and the transmission mechanism. The power drive unit 1 is typically composed of an electric motor, responsible for providing the mechanical energy required for the device's operation. The transmission mechanism converts the rotational motion of the power drive unit 1 into the reciprocating motion of the hydraulic end plunger 6. The hydraulic end is the core component that directly contacts the fluid and performs suction, discharge, and pressurization operations.

[0053] The hydraulic end is configured to include at least one fertilizer tank 4 and at least two clean water tanks 5. This multi-cylinder configuration allows the device to process two or more different media simultaneously. Each pump cylinder unit, whether it is the fertilizer tank 4 or the clean water tank 5, is equipped with an independent suction check valve 8 and a discharge check valve 9. These check valves can be in the form of ball valves, cone valves, or lift valves, and their function is to ensure that the fluid enters the pump cylinder from the suction side during the suction stroke and is discharged from the pump cylinder to the discharge side during the discharge stroke, preventing fluid backflow and thus ensuring pumping efficiency and metering accuracy.

[0054] The core component of the transmission mechanism is the crankshaft 18, which is driven to rotate by the power drive unit 1. Multiple connecting rods 10 connect different crank pins on the crankshaft 18 to the plungers 6 in each pump cylinder unit. When the crankshaft 18 rotates, the connecting rods 10 synchronously drive the plungers 6 of each cylinder to perform reciprocating linear motion. This mechanical linkage ensures the synchronous operation of all pump cylinders.

[0055] A key feature of this device is that the ratio of the total volume of fluid drawn in and discharged by the fertilizer tank 4 and all the clear water tanks 5 in each reciprocating motion is locked to a preset ratio by the mechanical structure of the transmission mechanism and / or the hydraulic end. For example, this preset ratio can be achieved by configuring cylinder liners 7 with different inner diameters for the fertilizer tank 4 and the clear water tanks 5, thus setting the single-stroke discharge volume by the difference in cylinder diameter when the plunger 6 has the same stroke. Alternatively, this ratio can also be set by adjusting the number of fertilizer tanks 4 and clear water tanks 5. This mechanical locking method ensures the accuracy and stability of the water-fertilizer mixing ratio, unaffected by external pressure fluctuations or changes in fluid properties.

[0056] All outlets of the one-way valves 9 are connected to a common outlet chamber 14 integrated inside the pump body 3. This common outlet chamber 14 is an internal cavity designed to collect high-pressure fluids from each pump cylinder. The common outlet chamber 14 is directly connected to the outlet 16 of the pump body 3. When the high-pressure fertilizer jet from the fertilizer cylinder 4 and the high-pressure clean water jet from the clean water cylinder 5 simultaneously enter the common outlet chamber 14, the high speed and kinetic energy of the fluids cause violent collisions, shearing, and diffusion within the chamber, resulting in forced turbulent mixing. This built-in forced mixing mechanism ensures rapid and uniform mixing of the fertilizer and clean water. The mixed fertilizer solution is then continuously pumped out through the outlet 16 and delivered to the irrigation network.

[0057] This device effectively solves the problems of redundant equipment, large footprint, slow response, and uneven mixing in existing integrated water and fertilizer systems by highly integrating a multi-cylinder plunger pump, transmission mechanism, and built-in mixing chamber into a single pump body. Its mechanically locked preset ratio ensures the accuracy and stability of water and fertilizer mixing, while the forced turbulent mixing within the shared outlet chamber 14 guarantees uniform mixing. This achieves integrated functions of water and fertilizer supply, precise metering, high-pressure mixing, and pressurized injection, improving water and fertilizer utilization efficiency and fertilization accuracy.

[0058] In a specific implementation, the crank eccentricity r1 of the connecting rod 10 connected to the plunger of the fertilizer cylinder 4 on the crankshaft 18 of the transmission mechanism is different from the crank eccentricity r2 of the connecting rod 10 connected to the plunger of the water cylinder 5, so that the plunger stroke of the fertilizer cylinder 4 and all the water cylinders 5 are different, thereby achieving the preset ratio.

[0059] Specifically, crank eccentricity refers to the distance from the rotation center of crankshaft 18 to the center of crankpin, which directly determines the stroke length of plunger 6 in reciprocating motion. By setting different values ​​for the crank eccentricity r1 corresponding to the connecting rod 10 connecting plunger 6 of fertilizer cylinder 4 and the connecting rod 10 connecting plunger 6 of water cylinder 5 during the design and manufacturing process of crankshaft 18, the difference in plunger stroke between fertilizer cylinder 4 and water cylinder 5 can be achieved in the mechanical structure. For example, this can be achieved by machining crankpin seats of different radii on crankshaft 18 or by using crank arms of different shapes. This design allows plunger 6 of fertilizer cylinder 4 and plunger 6 of water cylinder 5 to reciprocate with different stroke lengths under the synchronous drive of the same crankshaft 18. Since the plunger stroke is one of the key parameters determining the volume of fluid sucked and discharged in a single pump cycle (determined together with the plunger cross-sectional area), the single-cycle suction and discharge volume of the fertilizer tank 4 and the clear water tank 5 can be directly controlled by controlling different crank eccentricities. This difference in mechanical structure allows the ratio of the total volume of fluid sucked in and discharged by the fertilizer tank 4 and all the clear water tanks 5 in each reciprocating motion to be precisely locked to a preset ratio, thereby achieving precise mixing of water and fertilizer.

[0060] Through the above technical solution, this application enables an inherent difference in the plunger stroke of the fertilizer tank 4 and the clear water tank 5. This difference in mechanical structure directly determines the volume of fluid sucked and discharged by each pump cylinder in each reciprocating motion, thus eliminating the need for complex external control or frequent replacement of cylinder components. The preset mixing ratio of fertilizer solution and clear water can be precisely locked during the device design stage. This approach not only simplifies the structure and operation of the device and improves the stability and reliability of the mixing ratio, but also provides a flexible mechanical adjustment basis for achieving multiple preset ratios. For example, by replacing the crankshaft 18 with different combinations of eccentricities, different fertilization needs can be met, significantly improving the adaptability and practicality of the integrated water and fertilizer system.

[0061] In some embodiments described above, by adjusting the crank eccentricities r1 and r2 corresponding to the connecting rods 10 on the crankshaft 18 of the transmission mechanism that connect to the plungers 6 of the fertilizer cylinder 4 and the water cylinder 5, a difference in the plunger strokes of the fertilizer cylinder 4 and the water cylinder 5 can be achieved, thereby realizing a preset mixing ratio of fertilizer and water. However, in the actual design and manufacturing process, how to accurately determine these eccentricities r1 and r2 to ensure that the device can stably and accurately output a mixture of a specific ratio M is a technical problem that needs to be solved. Simply making the eccentricities different does not directly provide a quantitative design basis for achieving a specific preset ratio M.

[0062] In this regard, this application further proposes that the eccentricities r1 and r2 satisfy the following relationship: n·A_w·r2: A_f·r1≈ M : 1. In this relationship, n is the number of the clear water tanks 5, A_w is the plunger cross-sectional area of ​​a single clear water tank 5, A_f is the plunger cross-sectional area of ​​a single fertilizer tank 4, and M is the preset mixing ratio of clear water and fertilizer volume.

[0063] This formula provides a quantitative design method for determining the crank eccentricities r1 and r2 of the fertilizer liquid cylinder 4 and the clear water cylinder 5 in a multi-cylinder plunger pump fertigation device, to achieve a preset mixing ratio M between clear water and fertilizer liquid volumes. The core of this formula lies in linking the displacement of each cylinder (determined by the plunger cross-sectional area and stroke) with the required mixing ratio M. The plunger stroke is directly proportional to the crank eccentricity; therefore, by adjusting the eccentricity, the single-stroke displacement of each cylinder can be directly controlled. The number n of clear water cylinders 5 is a crucial parameter in device design, directly affecting the total displacement on the clear water side. By increasing or decreasing the number of clear water cylinders 5, the total volumetric output capacity on the clear water side can be adjusted within a certain range. The plunger cross-sectional area A_w of a single clear water cylinder 5 determines the displacement of that single clear water cylinder 5 per unit stroke. This parameter is typically determined by the inner diameter of the cylinder liner 7 and is a critical dimension in the hydraulic end design. Similarly, the plunger cross-sectional area A_f of a single fertilizer cylinder 4 determines the displacement of a single fertilizer cylinder 4 per unit stroke. This parameter is also determined by the inner diameter of the cylinder liner 7 of the fertilizer cylinder 4 and is the basis for fertilizer side displacement control. M represents the volume mixing ratio of clean water and fertilizer required by the user or application scenario, which is the goal of device design and operation. The above relationship is established precisely to achieve this goal.

[0064] Based on the aforementioned relationships, this application provides a method for accurately calculating and designing the crank eccentricities r1 and r2 in a transmission mechanism. This method directly correlates the required mixing ratio M of clean water and fertilizer solution with the mechanical structural parameters of the device (including the number n of clean water cylinders 5, the plunger cross-sectional area A_w of a single clean water cylinder 5, the plunger cross-sectional area A_f of a single fertilizer solution cylinder 4, and the crank eccentricities r1 and r2). This allows designers to directly calculate the required crank eccentricities based on the target mixing ratio M, combined with the known cylinder dimensions and number, thus accurately determining key dimensions before device manufacturing. This quantitative design method avoids traditional trial-and-error or complex calibration processes, significantly improving the efficiency of device design and the accuracy of the mixing ratio. It ensures that the integrated water and fertilizer device can stably and reliably output a mixed solution conforming to the preset ratio, thereby improving the precision and uniformity of fertilization.

[0065] In a further embodiment, the power drive unit 1 is configured as a variable frequency motor, and its speed is adjusted by an external frequency converter. A variable frequency motor is an AC motor that can adjust its speed by changing the power supply frequency. It is typically used in conjunction with a frequency converter to achieve smooth speed regulation over a wide range. The variable frequency motor can be a three-phase asynchronous motor or a permanent magnet synchronous motor, etc. Its design should meet the power and torque requirements of the integrated water and fertilizer system and have a sufficient speed adjustment range to cover the flow rate variations required for actual irrigation. The external frequency converter, as a power control device, converts the mains frequency power supply into a power supply with adjustable frequency and voltage, thereby precisely controlling the speed of the variable frequency motor. The frequency converter receives external control signals and outputs corresponding frequency and voltage according to the set values ​​to drive the variable frequency motor. This configuration allows the device to achieve stepless adjustment of the total output flow rate while maintaining a constant preset mixing ratio of fertilizer solution and clean water.

[0066] Through the above technical solution, since the ratio of the total fluid volume of fertilizer tank 4 to all clear water tanks 5 is precisely locked by the transmission mechanism and / or the mechanical structure of the hydraulic end, changes in the speed of the variable frequency motor will synchronously and proportionally affect the suction and discharge frequency and speed of all pump cylinders. This means that by adjusting the speed of the power drive unit 1, the total output flow rate of the water-fertilizer solution can be continuously and smoothly adjusted, while the mixing ratio remains constant. This improvement effectively solves the problem that, under the traditional fixed-speed drive method, the integrated water and fertilizer device is difficult to flexibly adjust the total output flow rate according to actual irrigation needs. Specifically, this solution enables the device to accurately match the water and fertilizer needs of different crops, different growth cycles, and different soil conditions, avoiding waste or deficiency of water and fertilizer, and significantly improving the accuracy, flexibility, and resource utilization efficiency of fertilization. At the same time, variable frequency speed regulation also brings energy-saving effects and reduces mechanical impact to a certain extent, helping to extend the service life of the equipment.

[0067] like Figure 2 and 3 As shown, the shared outlet chamber 14 is equipped with guide ribs 15, baffles, or asymmetric flow channel structures to guide the fertilizer jet and the clean water jet to collide and shear, enhancing the turbulent mixing effect. Specifically, the guide ribs 15 are protruding structures set inside the flow channel, usually in the form of strips or sheets. Their main function is to change the flow direction of the fluid, forcing the fluids that may originally be parallel or laminar to turn, causing them to collide and shear each other, thereby generating eddies and turbulence. The guide ribs 15 can be designed in various shapes and arrangements, such as spiral, grid, cross, or protrusions distributed along the flow channel wall. Their size, quantity, and angle can be optimized according to the geometry of the shared outlet chamber 14, the fluid properties, and the required mixing intensity. For example, multiple sets of guide ribs 15 can be set, each set of guide ribs 15 arranged at a certain angle to guide the fertilizer jet and the clean water jet to collide multiple times on different planes.

[0068] A baffle is a plate-shaped structure placed in a fluid channel to obstruct or change the direction of fluid flow. By creating obstacles in the fluid path, the fluid is forced to flow around them, generating local high-shear zones and eddies, thereby enhancing fluid mixing. The baffle can be fixed to the inner wall of the common outlet chamber 14, or it can be adjustable in angle or position. Its shape can be rectangular, circular, or other irregular shapes, and it can be used singly or in combination. For example, staggered baffles can be placed downstream of the confluence of fertilizer jets and clean water jets, forcing the fluid to repeatedly turn and mix within the gaps between the plates.

[0069] An asymmetric flow channel structure refers to a flow channel design within the shared outlet chamber 14 that lacks geometric symmetry. By breaking the symmetrical flow pattern of the fluid and introducing irregular fluid paths and velocity gradients, turbulence and eddies are naturally induced, promoting the mixing of different fluid components. This can be achieved by designing irregular cavity shapes, creating uneven surfaces on the flow channel walls, or allowing fluids from different inlets to enter the shared outlet chamber 14 at different angles, velocities, or positions. For example, the fertilizer inlet can be designed on one side of the shared outlet chamber 14, while the clean water inlet is designed on the other side, and the two are not on the same plane or axis, causing the two fluids to immediately generate an asymmetric interaction upon entry.

[0070] By employing the aforementioned technical solutions, the inclusion of guide ribs 15, baffles, or asymmetric flow channel structures within the shared outlet chamber 14 effectively guides the high-pressure fertilizer jet and the clean water jet to change direction upon entering the shared outlet chamber 14. Instead of simply merging, they are forced to undergo violent collisions, shearing, and vortex motion. These structures disrupt the laminar flow state of the fluids, significantly increasing the turbulence intensity and mixing interface area within the fluid, thereby greatly enhancing the forced mixing effect of the fertilizer solution and clean water. This ensures that the fertilizer solution and clean water can quickly and fully form a uniform fertilizer solution before being pumped out by the integrated water and fertilizer system, avoiding localized concentration imbalances, improving the precision of fertilization and the crop's nutrient absorption efficiency, and ultimately enhancing the overall performance and application value of the integrated water and fertilizer system.

[0071] In a further embodiment, the device also includes a pressure sensor, a conductivity sensor, a central controller, and a fertilizer supply control valve. The pressure sensor, used to monitor the output pressure of the fertilizer-water mixture in real time, is typically installed near the outlet 16 of the common outlet chamber 14 or at the beginning of the irrigation network, and can promptly reflect changes in network load, blockage, or system operating status. The conductivity sensor measures the conductivity of the fertilizer-water mixture. Since conductivity is closely related to the ion concentration in the solution (i.e., fertilizer concentration), it can indirectly reflect whether the concentration or mixing ratio of the fertilizer-water mixture meets the set requirements. It is typically installed after the outlet 16 to ensure that the measured solution is fully mixed. The central controller is the core control unit of the entire system. It can be a microprocessor (MCU), a programmable logic controller (PLC), or an industrial computer. Its main function is to receive and process monitoring data from the pressure sensor and / or conductivity sensor, and output corresponding control commands according to the preset control algorithm and target values. The fertilizer solution supply control valve is an adjustable valve used to precisely control the amount of fertilizer solution entering the fertilizer solution cylinder 4 or passing through the bypass pipeline, thereby achieving fine adjustment of the water-fertilizer mixing ratio. This valve can be an electric regulating valve, a proportional valve, or a solenoid valve, and is typically installed on the suction pipeline of the fertilizer solution cylinder 4, or on the bypass pipeline connected between the outlet of the discharge check valve 9 of the fertilizer solution cylinder 4 and the suction side.

[0072] The central controller performs feedback regulation based on monitoring data from pressure sensors and / or conductivity sensors. Specifically, the central controller can determine whether the system output flow rate meets requirements or is abnormal based on the monitoring data from the pressure sensor, and send a command to the power drive unit 1 to adjust its speed. For example, when the power drive unit 1 is a variable frequency motor, the central controller can change the motor speed by adjusting the output frequency of the inverter, thereby adjusting the total output flow rate of the pump. Simultaneously, the central controller compares the actual conductivity of the mixed liquid with the target conductivity based on the monitoring data from the conductivity sensor, calculates the deviation, and sends a control signal to the fertilizer supply control valve to adjust its opening. By changing the opening of the fertilizer supply control valve, the intake or bypass volume of the fertilizer can be precisely controlled, thereby dynamically adjusting the water-fertilizer mixing ratio. This dual feedback regulation mechanism enables the device to achieve closed-loop precise control of the output flow rate and mixing ratio.

[0073] Through the above technical solution, the integrated water and fertilizer system can sense and respond to changes in the external environment and internal operating status in real time. The central controller, utilizing feedback information from pressure and conductivity sensors, can dynamically and precisely adjust the rotational speed of the power drive unit 1 and the opening of the fertilizer supply control valve, thereby ensuring that the output flow rate and mixing ratio of the water-fertilizer mixture are always maintained at the set target values. This closed-loop control mechanism significantly improves the accuracy, stability, and automation level of water and fertilizer mixing, effectively avoiding deviations that may occur if the ratio is fixed solely by mechanical structures. This makes the fertilization process more refined, better adaptable to the water and fertilizer needs of different crops, different growth stages, and different soil conditions, thereby optimizing water and fertilizer utilization efficiency and promoting healthy crop growth.

[0074] In a specific implementation plan, this application further proposes a method for setting the fertilizer supply control valve, specifically including: the fertilizer supply control valve is set on the suction pipe of the fertilizer cylinder 4; or, the device further includes a bypass pipe, the bypass pipe is connected between the outlet of the discharge check valve 9 of the fertilizer cylinder 4 and the suction side, and the fertilizer supply control valve is connected in series on the bypass pipe.

[0075] The fertilizer solution supply control valve is located on the suction line of the fertilizer solution cylinder 4, meaning it is situated between the fertilizer solution source and the suction check valve 8 of the fertilizer solution cylinder 4. This valve directly regulates the flow rate of the fertilizer solution entering the fertilizer solution cylinder 4, thereby controlling the actual amount of fertilizer solution drawn in during each stroke of the plunger 6. This control valve can be an electric regulating valve, a proportional valve, or a solenoid valve, and its opening is adjusted by the central controller based on a preset mixing ratio and real-time monitoring data. By changing the valve opening, the effective suction volume of the fertilizer solution cylinder 4 can be precisely controlled, thus adjusting the fertilizer solution supply.

[0076] On the other hand, the device may also include a bypass pipe connected between the outlet of the discharge check valve 9 of the fertilizer cylinder 4 and the suction side, with a fertilizer supply control valve connected in series with the bypass pipe. The bypass pipe provides a path for a portion of the pressurized discharged fertilizer to flow back to the suction side of the fertilizer cylinder 4. In this configuration, the fertilizer supply control valve indirectly controls the net output amount of fertilizer by adjusting the flow rate of the returned fertilizer. When the valve opening increases, more fertilizer is bypassed and returned, thereby reducing the amount of fertilizer ultimately pumped into the common outlet chamber 14; conversely, when the valve opening decreases, the amount of returned fertilizer decreases, and the net output amount of fertilizer increases. This configuration is generally suitable for scenarios requiring more precise or wider-range adjustment and can effectively mitigate the impact of suction side pressure fluctuations on fertilizer supply.

[0077] By precisely setting the fertilizer solution supply control valve on the suction pipe of fertilizer solution cylinder 4, the amount of fertilizer solution entering fertilizer solution cylinder 4 can be directly adjusted, thereby achieving direct control of the fertilizer solution intake and ensuring that the mixing ratio of fertilizer solution and clean water can be precisely adjusted. Alternatively, by setting a bypass pipe and connecting the fertilizer solution supply control valve in series with it, partial recirculation of the pressurized and discharged fertilizer solution can be achieved, thereby indirectly and finely adjusting the net output amount of fertilizer solution. Both of these settings provide flexible and effective fertilizer solution supply control methods, enabling the central controller to accurately adjust the actual fertilizer solution supply based on sensor feedback data. This achieves closed-loop precise control of the water-fertilizer mixing ratio while maintaining a stable total output flow, significantly improving the fertilization accuracy and system responsiveness of the integrated water and fertilizer system.

[0078] In the above scheme, the ratio of the total fluid volume of the fertilizer tank 4 to all the clear water tanks 5 is set to be adjusted by replacing the crankshaft 18 with different eccentricity combinations, or replacing the cylinder liner 7 with different cylinder diameters, or changing the number configuration of the fertilizer tank 4 and the clear water tank 5, so as to achieve the switching of different preset ratios.

[0079] Specifically, adjusting the mixing ratio by replacing crankshafts 18 with different combinations of eccentricities means that the crank eccentricity r1 corresponding to the connecting rod 10 connected to the plunger 6 of the fertilizer tank 4, and the crank eccentricity r2 corresponding to the connecting rod 10 connected to the plunger 6 of the water tank 5, can be designed according to the preset ratio requirements. Different crankshafts 18 can be pre-manufactured, each crankshaft 18 having a specific combination of r1 and r2, or a relative size relationship between r1 and r2. When the mixing ratio needs to be adjusted, the operator can select and replace the corresponding crankshaft 18 according to the actual agronomic requirements. For example, if it is necessary to increase the relative ratio of fertilizer and liquid, a crankshaft 18 that relatively increases the crank eccentricity r1 corresponding to the fertilizer tank 4 can be replaced, thereby increasing the plunger stroke of the fertilizer tank 4, and thus increasing the intake and discharge of fertilizer and liquid in each reciprocating motion. Replacing the crankshaft 18 usually involves disassembling and reinstalling the transmission mechanism, and it is necessary to ensure the reliability of the connection and the transmission accuracy.

[0080] Alternatively, the mixing ratio can be adjusted by replacing the cylinder liner 7 with one of different diameters. The diameter of the cylinder liner 7 directly determines the effective cross-sectional area of ​​the plunger 6. The fertilizer tank 4 and the water tank 5 can be designed with replaceable cylinder liners 7. When the mixing ratio needs to be adjusted, the plunger cross-sectional area can be changed by replacing the cylinder liner 7 of the fertilizer tank 4 or the water tank 5. For example, replacing the cylinder liner 7 of the fertilizer tank 4 with one of a larger diameter can increase the single-pass displacement of the fertilizer tank 4 without changing the plunger stroke, thereby increasing the relative proportion of fertilizer. When replacing the cylinder liner 7, it is necessary to ensure its sealing with the pump body 3 and the fitting accuracy with the plunger 6 to avoid leakage or wear. Cylinder liners 7 of different diameters should be standardized to facilitate quick and accurate replacement.

[0081] Alternatively, the mixing ratio can be adjusted by changing the number of fertilizer tank 4 and water tank 5. This can be achieved by reserving installation positions for multiple pump cylinder units in the device design, and selectively installing or activating a specific number of fertilizer tank 4 and water tank 5 as needed. For example, if the device is designed to accommodate two fertilizer tank 4 and four water tanks 5, only one fertilizer tank 4 and four water tanks 5 can be installed or activated when a lower fertilizer-to-water ratio is required; and two fertilizer tank 4 and four water tanks 5 can be installed or activated when a higher fertilizer-to-water ratio is required. This approach may require a more complex pump body 3 structural design, or additional control valves to selectively isolate or activate the pump cylinder units.

[0082] Through the above technical solution, this integrated water and fertilizer device overcomes the limitations of a single fixed mixing ratio, enabling flexible switching of preset mixing ratios. Users can quickly switch to the desired mixing ratio through simple mechanical adjustments based on the differentiated requirements of different crops and different growth stages, significantly improving the device's versatility and practicality. This ratio switching method, based on physical adjustment of the mechanical structure, ensures that the adjusted mixing ratio maintains high precision and stability, avoiding inaccurate mixing ratios caused by flow fluctuations or control errors, thus guaranteeing the effectiveness of precision fertilization.

[0083] Example 2:

[0084] This embodiment proposes a water-fertilizer mixing and injection method using the device described in Embodiment 1.

[0085] The method includes the following steps: connecting the suction pipe of the fertilizer tank 4 to the fertilizer source, connecting the suction pipe of the water tank 5 to the water source, and connecting the outlet 16 to the irrigation network; starting the power drive unit 1 to drive the crankshaft 18 to rotate, which in turn drives each plunger 6 to reciprocate via the connecting rod 10, quantitatively sucking in and pressurizing the fertilizer and water according to the preset ratio; the pressurized fertilizer and water enter the common outlet chamber 14 in the form of a high-speed jet, where forced turbulent mixing occurs to form a uniform water-fertilizer solution; the mixed water-fertilizer solution is continuously pumped into the irrigation network through the outlet 16; during this process, the total output flow rate is adjusted by regulating the rotation speed of the power drive unit 1, while the preset ratio remains unchanged by the mechanical structure.

[0086] Through the above technical solution, the pressurized fertilizer solution and clean water undergo forced turbulent mixing in the form of a high-speed jet within the shared outlet chamber 14, ensuring rapid and uniform mixing. Simultaneously, the preset ratio is locked by a mechanical structure, guaranteeing a precise and constant water-fertilizer mixing ratio, unaffected by external pressure fluctuations. This design effectively overcomes the shortcomings of existing technologies, such as equipment redundancy, response lag, uneven mixing, and limited functionality. It achieves a high degree of integration of water and fertilizer supply, precise metering, high-pressure mixing, and pressurized injection, significantly improving water and fertilizer utilization efficiency and fertilization accuracy.

[0087] In some embodiments described above, this application proposes a water-fertilizer integration device and its usage method based on a multi-cylinder plunger pump. The water-fertilizer mixing ratio is locked through a mechanical structure, and the total output flow rate is adjusted by regulating the rotational speed of the power drive unit 1. However, in actual operation, due to environmental factors, changes in fluid characteristics, or equipment wear, the actual fertilizer application rate and mixing ratio may deviate from the preset values, making precise control of the water-fertilizer mixing difficult. To address this, this application further proposes a closed-loop control system that monitors the pressure and conductivity of the mixed liquid in real time, and adjusts the rotational speed of the power drive unit 1 and / or the opening of the fertilizer supply control valve located on the fertilizer inlet pipe or bypass pipe based on the monitoring values, thereby achieving closed-loop precise control of the fertilizer application rate and mixing ratio.

[0088] Specifically, this closed-loop control system typically consists of sensors, controllers, and actuators. Pressure sensors, which can be piezoresistive, piezoelectric, or capacitive sensors, monitor the pressure of the fertilizer mixture in the irrigation network in real time. These sensors convert pressure signals into electrical signals to reflect the system's operating status, the presence of blockages, or changes in flow. Conductivity sensors, which can be electrode-type or electromagnetic induction-type sensors, monitor the conductivity of the fertilizer mixture in real time. They indirectly reflect the concentration and mixing ratio of the fertilizer solution by measuring the conductivity of the mixture. These sensors can continuously or periodically collect data and transmit it to a central controller for processing.

[0089] After receiving monitoring data from the pressure sensor and / or conductivity sensor, the central controller compares it with a preset target value. When there is a deviation between the monitored value and the target value, the central controller calculates the required adjustment amount according to a preset control algorithm (such as a PID control algorithm) and sends a control command to the actuator. The actuator includes a power drive unit 1 and a fertilizer supply control valve. The speed regulation of the power drive unit 1 is usually achieved through a frequency converter. The frequency converter changes the power supply frequency and voltage of the motor according to the command of the central controller, thereby precisely controlling the output speed of the power drive unit 1 and thus regulating the total output flow of the integrated water and fertilizer system. The opening adjustment of the fertilizer supply control valve is achieved through an electric actuator. This valve can be installed on the suction pipe of the fertilizer cylinder 4 to directly control the amount of fertilizer sucked in; or, when the device also includes a bypass pipe, the valve can be connected in series with the bypass pipe to indirectly control the amount of fertilizer entering the fertilizer cylinder 4 by adjusting the bypass flow. By adjusting the opening of the fertilizer supply control valve, the amount of fertilizer supplied can be precisely controlled, thereby adjusting the water-fertilizer mixing ratio.

[0090] Through the above technical solution, this application overcomes the limitations of relying solely on mechanical structures to lock the ratio and open-loop flow regulation. Real-time monitoring of the pressure and conductivity of the mixed solution allows the system to promptly detect potential deviations during actual operation. The central controller performs intelligent feedback regulation based on this monitoring data, precisely controlling the rotational speed of the power drive unit 1 to adjust the total output flow, and / or adjusting the opening of the fertilizer supply control valve to fine-tune the fertilizer supply amount, thereby achieving closed-loop precise control of the fertilizer application rate and mixing ratio. This not only ensures that the mixing ratio of the water and fertilizer solution remains within the target range, avoiding crop fertilizer damage or insufficient fertility due to ratio imbalance, but also dynamically adjusts the total flow based on actual pressure changes in the irrigation network, ensuring the uniformity and stability of irrigation. This precise control significantly improves water and fertilizer utilization efficiency, saves water and fertilizer resources, and provides crops with a more stable and suitable growth environment.

[0091] The following example will provide a more detailed explanation of the above technical solution:

[0092] In a modern agricultural irrigation scenario, users need to apply precise integrated water and fertilizer to farmland. The crops in this field require irrigation at a fertilizer-to-water ratio of 1:200, and the total irrigation flow needs to be adjusted in real time based on soil moisture and crop growth stage. Traditional premixed systems suffer from mixing lag and poor uniformity, while injection systems have low integration and their mixing effect is limited by pipeline conditions.

[0093] This example uses a water and fertilizer integration device based on a multi-cylinder plunger pump. The core of this device is a pump body 3, which integrates a power drive unit 1, a transmission mechanism, and a hydraulic end.

[0094] Device configuration and working principle:

[0095] 1. Hydraulic End Design: The hydraulic end of the device is equipped with one fertilizer solution tank 4 and two clean water tanks 5. Each pump unit, whether it is the fertilizer solution tank 4 or the clean water tank 5, is independently equipped with an intake check valve 8 and an exhaust check valve 9. The intake pipe of the fertilizer solution tank 4 is connected to the concentrated fertilizer solution source, while the intake pipes of the two clean water tanks 5 are connected to the clean water source. This multi-tank independent intake design avoids the complex structure and floor space of traditional premixing tanks, and realizes direct access to the water and fertilizer sources.

[0096] 2. Power and Transmission: The power drive unit 1 uses a variable frequency motor, and the speed is adjusted by an external frequency converter. This motor drives the crankshaft 18 in the transmission mechanism. The crankshaft 18 is connected to the plungers 6 in the fertilizer tank 4 and the clean water tank 5 via connecting rods 10. When the variable frequency motor starts and rotates, the crankshaft 18 synchronously drives all the plungers 6 to reciprocate.

[0097] 3. Preset Ratio Locking: To achieve a 1:200 fertilizer-to-water mixing ratio, the mechanical structure of the transmission mechanism is specially designed. Specifically, the crank eccentricity r1 corresponding to the connecting rod 10 connected to the plunger of the fertilizer cylinder 4 on the crankshaft 18 is different from the crank eccentricity r2 corresponding to the connecting rod 10 connected to the plunger of the clear water cylinder 5. By precisely designing the difference between r1 and r2, and combining the plunger cross-sectional areas of the fertilizer cylinder 4 and the clear water cylinder 5, the ratio of the total volume of fertilizer and clear water sucked in and discharged by the device in each reciprocating motion is precisely locked by the mechanical structure to a preset 1:200. For example, if the number n of clear water cylinders 5 is 2, the plunger cross-sectional area of ​​a single clear water cylinder 5 is A_w, and the plunger cross-sectional area of ​​a single fertilizer cylinder 4 is A_f, then the eccentricities r1 and r2 satisfy the relationship 2·A_w·r2 : A_f·r1 ≈ 200 : 1. This mechanical locking method ensures the constantness and accuracy of the mixing ratio, unaffected by outlet pressure fluctuations, thus solving the problem of the mixing ratio being affected by the flow state in traditional injection systems. If the mixing ratio needs to be adjusted, it can be achieved by replacing the crankshaft 18 with different eccentricity combinations, replacing the cylinder liner 7 with different cylinder diameters, or changing the number configuration of the fertilizer tank 4 and the clear water tank 5, thereby improving the adaptability of the device.

[0098] 4. Forced Mixing and Discharge: The outlets of all discharge check valves 9 are connected to a common outlet chamber 14 integrated inside the pump body 3. This common outlet chamber 14 is directly connected to the discharge outlet 16 of the pump body 3, which is connected to the irrigation network. When the plunger 6 pressurizes and discharges the fertilizer solution and clean water, the high-pressure fertilizer solution and clean water simultaneously enter the common outlet chamber 14 in the form of high-speed jets. To enhance the mixing effect, guide ribs 15 are provided inside the common outlet chamber 14. These guide ribs 15 can guide the fertilizer solution jet and the clean water jet to collide and shear violently, forcibly generating turbulence, thereby instantly completing uniform mixing inside the pump body to form a uniform water-fertilizer solution. This built-in, high-pressure forced mixing avoids the problems of uneven mixing and lag in premixed systems, and is also superior to the inefficiency of injection systems that rely on natural mixing through pipelines.

[0099] 5. Flow and proportional control:

[0100] Total Flow Rate Adjustment: Users can achieve stepless adjustment of the total output flow rate by adjusting the speed of the power drive unit 1 (variable frequency motor). For example, when an increase in irrigation volume is needed, the motor speed is increased; when a decrease in irrigation volume is needed, the motor speed is decreased. During this process, because the mixing ratio is locked by the mechanical structure, the fertilizer-water mixing ratio always remains unchanged at the preset 1:200, regardless of changes in the total flow rate. This solves the problem of deteriorated mixing effect in traditional systems under variable flow conditions.

[0101] Closed-loop precision control: The device is also equipped with a pressure sensor, a conductivity sensor, and a central controller. The pressure sensor monitors the pressure of the irrigation network, while the conductivity sensor monitors the conductivity of the mixed solution (reflecting the fertilizer concentration) in real time. Based on this monitoring data, the central controller adjusts the rotation speed of the power drive unit 1 to maintain stable network pressure and total flow requirements. Simultaneously, a fertilizer supply control valve is installed on the suction line of the fertilizer tank 4. The central controller can also fine-tune the opening of the fertilizer supply control valve based on the conductivity sensor's monitoring values, precisely regulating the fertilizer intake amount. This achieves closed-loop precision control of the output flow rate and mixing ratio, ensuring accurate fertilization.

[0102] Operating procedures:

[0103] The user connects the suction pipe of fertilizer tank 4 to the fertilizer source, the suction pipe of water tank 5 to the water source, and the outlet 16 to the irrigation network. The power drive unit 1 is started, driving the crankshaft 18 to rotate, which in turn drives each plunger 6 to reciprocate via connecting rod 10. The device quantitatively draws in and pressurizes the fertilizer solution and water at a preset ratio of 1:200. The pressurized fertilizer solution and water enter the common outlet chamber 14 in the form of a high-speed jet, where forced turbulent mixing occurs under the action of guide ribs 15, forming a uniform water-fertilizer solution. The mixed water-fertilizer solution is continuously pumped into the irrigation network through outlet 16. During this process, the total output flow rate is adjusted by regulating the speed of the power drive unit 1, while the preset ratio remains unchanged by the mechanical structure. The closed-loop control system monitors the pressure and conductivity of the mixed solution in real time, and adjusts the speed of the power drive unit 1 and / or the opening of the fertilizer supply control valve based on the monitoring values ​​to achieve precise control of the fertilizer application rate and mixing ratio.

[0104] Through the above example, the device highly integrates the processes of fertilizer absorption, water absorption, high-pressure instantaneous mixing, and pressurized injection into a single pump body. It has a compact structure, rapid response, high mixing uniformity, and precise and constant mixing ratio, effectively solving the shortcomings of existing integrated water and fertilizer systems, such as equipment redundancy, slow response, uneven mixing, or single function and low integration.

[0105] The above description is merely an embodiment of this application and is not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A water and fertilizer integration device based on a multi-cylinder plunger pump, comprising: Pump body (3), power drive unit (1), transmission mechanism and hydraulic end; The hydraulic end includes at least one fertilizer tank (4) and at least two clean water tanks (5), and each pump cylinder unit is equipped with an independent suction check valve (8) and discharge check valve (9). The transmission mechanism includes a crankshaft (18) driven by the power drive unit (1) and connecting rods (10) that connect the crankshaft (18) to the plungers (6) in each pump cylinder unit. The crankshaft (18) synchronously drives the plungers (6) of each cylinder to reciprocate. The ratio of the total volume of fluid sucked in and discharged by the fertilizer cylinder (4) and all the clear water cylinders (5) in each reciprocating motion is locked to a preset ratio by the transmission mechanism and / or the mechanical structure of the hydraulic end. The outlets of all the discharge check valves (9) are connected to a common outlet chamber (14) integrated inside the pump body (3), which is directly connected to the outlet (16) of the pump body (3) so that the high-pressure fertilizer solution from each cylinder and the clean water are forcibly mixed in the common outlet chamber (14) and then pumped out.

2. The water and fertilizer integration device based on a multi-cylinder plunger pump according to claim 1, characterized in that, The crank eccentricity r1 of the connecting rod (10) connected to the plunger of the fertilizer cylinder (4) on the crankshaft (18) of the transmission mechanism is different from the crank eccentricity r2 of the connecting rod (10) connected to the plunger of the water cylinder (5), so that the plunger stroke of the fertilizer cylinder (4) and all the water cylinders (5) are different, thereby realizing the preset ratio.

3. The water and fertilizer integration device based on a multi-cylinder plunger pump according to claim 2, characterized in that, The eccentricities r1 and r2 satisfy the following relationship: n·A_w·r2 : A_f·r1 ≈ M : 1 In the formula: n is the number of the clean water tanks (5). A_w is the cross-sectional area of ​​the plunger in a single clear water tank (5). A_f is the cross-sectional area of ​​the plunger in a single fertilizer cylinder (4). M is the preset mixing ratio of clean water and fertilizer solution.

4. The water and fertilizer integration device based on a multi-cylinder plunger pump according to claim 1, characterized in that, The power drive unit (1) is a variable frequency motor, which adjusts the speed through an external frequency converter to achieve stepless adjustment of the total output flow while maintaining the preset ratio unchanged.

5. The water and fertilizer integration device based on a multi-cylinder plunger pump according to claim 1, characterized in that, The shared water outlet chamber (14) is equipped with guide ribs (15), baffles or asymmetric flow channel structures to guide the fertilizer jet and the clear water jet to collide and shear, thereby enhancing the turbulent mixing effect.

6. The apparatus according to claim 1, characterized in that, It also includes a pressure sensor, a conductivity sensor, a central controller, and a fertilizer supply control valve; the central controller is used to adjust the rotation speed of the power drive unit (1) and / or the opening of the fertilizer supply control valve based on the monitoring data of the pressure sensor and / or the conductivity sensor, so as to achieve closed-loop precise control of the output flow rate and mixing ratio.

7. A water and fertilizer integration device based on a multi-cylinder plunger pump according to claim 6, characterized in that, The fertilizer supply control valve is located on the suction pipe of the fertilizer cylinder (4); or, the device further includes a bypass pipe, which is connected between the outlet of the discharge check valve (9) of the fertilizer cylinder (4) and the suction side, and the fertilizer supply control valve is connected in series on the bypass pipe.

8. A water and fertilizer integration device based on a multi-cylinder plunger pump according to any one of claims 1 to 7, characterized in that, The ratio of the total fluid volume of the fertilizer tank (4) to all the clear water tanks (5) is set to be adjusted by replacing the crankshaft (18) with different eccentricity combinations, or replacing the cylinder liner (7) with different cylinder diameters, or changing the number configuration of the fertilizer tank (4) and the clear water tank (5) to achieve switching of different preset ratios.

9. A method for mixing and injecting water and fertilizer using the apparatus as described in any one of claims 1 to 8, characterized in that, Includes the following steps: Connect the suction pipe of the fertilizer tank (4) to the fertilizer source, connect the suction pipe of the water tank (5) to the water source, and connect the outlet (16) to the irrigation network. Start the power drive unit (1) to drive the crankshaft (18) to rotate, and drive each plunger (6) to reciprocate through the connecting rod (10), and quantitatively suck in and pressurize the fertilizer liquid and water according to the preset ratio; The pressurized fertilizer solution and clean water enter the common water outlet chamber (14) in the form of a high-speed jet, and forced turbulent mixing occurs in the common water outlet chamber (14) to form a uniform water-fertilizer solution; The mixed water and fertilizer solution is continuously pumped into the irrigation network through the outlet (16); during this process, the total output flow rate is adjusted by adjusting the rotation speed of the power drive unit (1), and the preset ratio remains unchanged by the mechanical structure.

10. The method according to claim 9, characterized in that, Also includes: The closed-loop control system monitors the pressure and conductivity of the mixed liquid in real time, and adjusts the speed of the power drive unit (1) and / or the opening of the fertilizer supply control valve set on the fertilizer inhalation pipeline or bypass pipe according to the monitoring value feedback, so as to achieve closed-loop precise control of fertilizer application and mixing ratio.

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