Method and device for evaluating atomization performance of pressure nozzle

Abstract

The invention provides a method and device for evaluating the atomization performance of a pressure nozzle, and relates to the technical field of atomization performance test.The method comprises the steps that firstly, the total volume and total kinetic energy of fog drops are determined when the pressure nozzle sprays mist, and the total kinetic energy of the fog drops is calculated according to the inlet flow speed of liquid in a pressure nozzle pipeline and the nozzle flow speed of the liquid at a nozzle; the cavity pressure of the pressure nozzle is calculated, the initial energy of the pressure nozzle under the weighted volume is calculated by combining the total volume of the fog drops, and the ratio of the total kinetic energy of the fog drops to the initial energy serves as the atomization performance index of the pressure nozzle. The method is used for solving the problems that in the prior art, a method for evaluating the atomization performance of the pressure nozzle is insufficient in universality, and the atomization performance of the pressure nozzle is difficult to directly and accurately evaluate, and a new technical method is provided for performance evaluation and model selection of the pressure nozzle.

Description

Technical Field

[0001] The present invention relates to the technical field of atomization performance testing, and particularly relates to a method and device for evaluating the atomization performance of a pressure nozzle. Background Art

[0002] In application fields such as agricultural plant protection, industrial spraying, and fire fighting spraying, the pressure nozzle plays an important role in improving agricultural production efficiency and resource utilization rate by virtue of its unique design and working principle. The spraying efficiency of the pressure nozzle directly affects the operation quality and energy utilization rate. As the core index for evaluating the performance of the nozzle, the atomization performance reflects the conversion efficiency of liquid kinetic energy into droplet kinetic energy.

[0003] In the prior art, the evaluation of the spraying performance of the pressure nozzle mainly relies on experimental measurement and theoretical analysis, including the following several types: One is the optical measurement method: such as a laser particle size analyzer, a PIV particle image velocimeter, a laser Doppler velocimeter, etc., which are used to measure the particle size and velocity distribution of droplets. The second is the theoretical calculation method: By establishing a mathematical model of the internal flow and spraying of the nozzle, and combining the principles of fluid mechanics and thermodynamics, the spraying performance is predicted. The third is the empirical evaluation method: Based on a large amount of experimental data, an empirical formula for the spraying performance of the nozzle is summarized. These methods do not have universality, and it is difficult to directly and accurately evaluate the spraying performance of the pressure nozzle, and they cannot provide strong support for the optimization design and selection of the pressure nozzle. Summary of the Invention

[0004] The present invention provides a method and device for evaluating the atomization performance of a pressure nozzle to solve the problems that the existing methods for evaluating the spraying performance of the pressure nozzle lack universality and are difficult to directly and accurately evaluate the atomization performance of the pressure nozzle.

[0005] The present invention provides a method for evaluating the atomization performance of a pressure nozzle, including: Determining the total volume of droplets and the total kinetic energy of droplets when the pressure nozzle sprays; Obtaining the inlet flow velocity of the liquid inside the pressure nozzle pipeline and the nozzle flow velocity at the nozzle; Calculating the cavity pressure of the pressure nozzle according to the inlet flow velocity and the nozzle flow velocity; Calculating the initial energy of the pressure nozzle under the weighted volume based on the cavity pressure, the inlet flow velocity, and the total volume of droplets, and taking the ratio of the total kinetic energy of the droplets to the initial energy as the atomization performance index of the pressure nozzle.

[0006] In some embodiments, the process of determining the total volume of droplets when the pressure nozzle sprays includes: When the pressure nozzle sprays, obtaining the particle size of a single droplet collected by a phase Doppler particle analyzer, and calculating the single droplet volume according to the particle size; Within the spray range of the spray, determine the total number of droplets during spraying according to the number of effective droplets collected at the droplet measurement points, where the droplet measurement points are evenly distributed within the spray range; Sum the volumes of individual droplets of the total number of droplets to obtain the total volume of droplets when the pressure nozzle sprays.

[0007] In some embodiments, the process of determining the total kinetic energy of droplets when the pressure nozzle sprays includes: Within the spray range of the spray, assign a corresponding position weight to each droplet measurement point, where the position weight of each droplet measurement point is negatively correlated with the actual distance from the pressure nozzle; After the pressure nozzle sprays, for each droplet collected at the droplet measurement point, respectively determine the first velocity in the horizontal direction and the second velocity in the vertical direction; At each droplet measurement point, calculate the theoretical spray kinetic energy of each droplet according to the first velocity and the second velocity, and perform weighted calculation on the theoretical spray kinetic energy through the position weight to obtain the actual spray kinetic energy of the droplet; Sum the actual spray kinetic energies of each droplet measurement point to obtain the total kinetic energy of droplets when the pressure nozzle sprays.

[0008] In some embodiments, the obtaining of the inlet flow velocity of the liquid inside the pressure nozzle pipeline and the nozzle flow velocity at the nozzle includes: Obtain the liquid flow rate inside the pressure nozzle collected by the electromagnetic flowmeter; Calculate the inlet cross-sectional area and the nozzle cross-sectional area of the pressure nozzle respectively; Take the ratio of the liquid flow rate to the inlet cross-sectional area as the inlet flow velocity of the liquid inside the pressure nozzle pipeline, and take the ratio of the liquid flow rate to the nozzle cross-sectional area as the nozzle flow velocity at the nozzle of the pressure nozzle.

[0009] In some embodiments, the calculating of the cavity pressure of the pressure nozzle according to the inlet flow velocity and the nozzle flow velocity includes: Determine the pressure loss during the flow of the liquid in the pressure nozzle pipeline, where the pressure loss includes the friction loss determined by the Darcy friction coefficient and the local loss determined by the local loss coefficient; According to the pipeline pressure of the pressure nozzle and the inlet flow velocity, calculate the total inlet pressure of the pressure nozzle, and according to the unknown outlet pressure of the pressure nozzle, the nozzle flow velocity and the pressure loss, determine the total nozzle pressure of the pressure nozzle; Based on the total inlet pressure and the total nozzle pressure, construct a modified Bernoulli equation; Solve the modified Bernoulli equation, and use the obtained unknown outlet pressure as the cavity pressure of the pressure nozzle.

[0010] In some embodiments, calculating the initial energy of the pressure nozzle at the weighted volume based on the cavity pressure, the inlet flow rate, and the total volume of the droplets includes: Calculate the inlet kinetic energy of the liquid inside the pressure nozzle according to the inlet flow rate and the total volume of the droplets; Calculate the pressure energy of the liquid inside the pressure nozzle according to the cavity pressure and the total volume of the droplets; Sum the inlet kinetic energy and the pressure energy to obtain the initial energy corresponding to the weighted volume inside the pressure nozzle.

[0011] The present invention also provides an atomization performance evaluation device for a pressure nozzle, including: A determination module for determining the total volume of the droplets and the total kinetic energy of the droplets when the pressure nozzle sprays; An acquisition module for acquiring the inlet flow rate of the liquid inside the pressure nozzle pipeline and the nozzle flow rate at the nozzle; A calculation module for calculating the cavity pressure of the pressure nozzle according to the inlet flow rate and the nozzle flow rate; An evaluation module for calculating the initial energy of the pressure nozzle at the weighted volume based on the cavity pressure, the inlet flow rate, and the total volume of the droplets, and using the ratio of the total kinetic energy of the droplets to the initial energy as the atomization performance index of the pressure nozzle.

[0012] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, it implements the atomization performance evaluation method of the pressure nozzle as described in any one of the above.

[0013] The present invention also provides a non-transitory computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it implements the atomization performance evaluation method of the pressure nozzle as described in any one of the above.

[0014] The present invention also provides a computer program product, including a computer program. When the computer program is executed by a processor, it implements the atomization performance evaluation method of the pressure nozzle as described in any one of the above.

[0015] The atomization performance evaluation method and device for a pressure nozzle provided by the present invention calculate the atomization performance index by calculating the initial energy and the total kinetic energy of the droplets under the weighted volume. As a comprehensive evaluation index for the pressure nozzle, it can comprehensively reflect the spraying performance of the pressure nozzle, provide strong support for the optimization design and selection of the pressure nozzle, and the comprehensive evaluation index can be applied to the spraying performance evaluation of different types of pressure nozzles, with good universality. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the accompanying drawings required for the implementation examples or the description of the prior art will be briefly introduced one by one below. Obviously, the accompanying drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0017] Figure 1 It is a schematic flowchart of the atomization performance evaluation method for a pressure nozzle provided by the present invention.

[0018] Figure 2 It is a schematic principle diagram of the atomization performance evaluation method for a pressure nozzle provided by the present invention.

[0019] Figure 3 It is a schematic structural diagram of the atomization performance evaluation device for a pressure nozzle provided by the present invention.

[0020] Figure 4 It is a schematic structural diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0022] The atomization performance evaluation method and device for a pressure nozzle of the present invention will be described below in conjunction with the accompanying drawings. Figure 1 It is a schematic flowchart of the atomization performance evaluation method for a pressure nozzle provided by the present invention. As Figure 1 shown, the method includes the following steps 101 to 104, which will be specifically described below.

[0023] Step 101: Determine the total volume and total kinetic energy of the droplets when the pressure nozzle sprays.

[0024] As Figure 2 shown,Figure 2 The figure shows a schematic diagram of the pressure nozzle during spraying. When the pressure nozzle sprays, multiple droplet measurement points are set at a position L meters away in the vertical direction of the nozzle orifice of the pressure nozzle. Figure 2 For example, 10 droplet measurement points are shown. The liquid for spraying can be tap water, pesticides, etc. A phase Doppler particle analyzer is installed at the droplet measurement points. By adjusting the spatial angle between the laser transmitter and the receiver, the measurement area of the droplet measurement points covers the spray core area of the pressure nozzle, and green stripe flashes can be clearly seen through the receiver slit. According to the nozzle type (fan-shaped / conical) of the pressure nozzle and the physical properties of the solution, the laser wavelength, sampling frequency, and particle size detection range are set for the phase Doppler particle analyzer, and standard particle size particles are used for calibration to verify that the particle size measurement error is ≤±2% and the velocity measurement error is ≤±0.5 m / s. After the pressure nozzle starts spraying and stabilizes the pressure, the phase Doppler particle analyzer synchronously collects the particle size and two-dimensional velocity vector of the droplets on the horizontal plane at a distance L from the nozzle. During the collection process, the phase Doppler particle analyzer is moved to specific droplet measurement points through a three-axis positioning and moving system to collect droplet parameters. The spray control system provides a stable pressure and flow rate in the pipeline and monitors the pressure and liquid flow rate in the pipeline in real time. Finally, in a single sampling period, n effective particle data can be covered and collected, the droplet parameters of m droplet measurement points can be evenly collected, and the total number of effective droplets finally collected is N. The environmental interference signals are removed by threshold filtering (signal-to-noise ratio > 30 dB) to ensure that the data validity is greater than 95%. Subsequently, the kinetic energy of a single droplet is calculated using the two-dimensional velocity vector, and then the kinetic energies of all effective droplets are summed to obtain the total kinetic energy. And according to the particle size of the droplets, the volume of each droplet can be calculated, and the volumes of N droplets are summed to obtain the total droplet volume.

[0025] The following specifically introduces the determination process of the total droplet volume when the pressure nozzle sprays.

[0026] First, when the pressure nozzle sprays, the particle size of a single droplet collected by the phase Doppler particle analyzer is obtained, and the volume of a single droplet is calculated based on the particle size. The particle size of a single droplet is directly measured by the phase Doppler particle analyzer and is denoted as , where i represents the i-th droplet, and the formula for calculating the volume of a single droplet is as follows: (1) Further, within the spray range of the spray, the total number of droplets during spraying is determined based on the number of effective droplets collected at the droplet measurement points. In the embodiment of the present invention, the phase Doppler particle analyzer is arranged within the spray range of the pressure nozzle. This spray range defines the area range of the pressure nozzle spraying, and the droplet measurement points are evenly distributed within the spray range, that is, the horizontal distances between the droplet measurement points are the same. Each droplet measurement point can cover and collect n effective droplets. Thus, during a single sampling period of the phase Doppler particle analyzer, the effective droplets at each droplet measurement point are evenly collected. Finally, the total number of effective droplets obtained is N. The number m of droplet measurement points is generally 10, n can be taken as 1000, and then N is 10000.

[0027] Finally, the volumes of individual droplets are summed to obtain the total droplet volume during spraying by the pressure nozzle, denoted as . Here, the total droplet volume is the sum of the volumes of N individual droplets, and the calculation formula is as follows: (2) In the embodiment of the present invention, by using a phase Doppler particle analyzer to collect the effective droplets during spraying by the pressure nozzle, and by evenly arranging droplet measurement points within the spray range to count the number of effective droplets, the influence of spatial non-uniformity in the spraying area can be reduced, and thus the calculation accuracy of the total droplet volume can be improved.

[0028] Next, the determination process of the total kinetic energy of droplets during spraying by the pressure nozzle is continued to be introduced.

[0029] Since the droplets are collected within the spray range of the spray and are measured by evenly distributed and differently positioned droplet measurement points, the distances and speeds of each droplet reaching the droplet measurement points after spraying are different. Because the speed determines the kinetic energy of the droplet, assuming that each droplet is the same, there are differences in the kinetic energies of the droplets collected at different droplet measurement points. Based on this rule, in the embodiment of the present invention, within the spray range of the spray, a corresponding position weight is assigned to each droplet measurement point, denoted as , where j represents the jth droplet measurement point. Among them, the position weight of each droplet measurement point is negatively correlated with the actual distance from the pressure nozzle, that is, the smaller the actual distance of the droplet measurement point from the pressure nozzle, the greater the assigned position weight, and vice versa. And if the actual distances of two droplet measurement points from the pressure nozzle are the same, then the assigned position weights are also the same.

[0030] For example Figure 2As shown in the figure, the 5th and 6th droplet measurement points are directly below the pressure nozzle and have the smallest distance from the pressure nozzle. Therefore, the position weights assigned to these two droplet measurement points are the highest, which is 0.5. Since the actual distances of the 5th and 6th droplet measurement points from the pressure nozzle are the same, the assigned position weights are also the same, both being 0.5. For the other droplet measurement points on both sides, the distances from the pressure nozzle are getting farther and farther, so the assigned position weights are getting lower and lower, and are assigned as 0.4, 0.3, 0.2, and 0.1 respectively.

[0031] Next, after the pressure nozzle sprays, for each droplet collected at the droplet measurement point, the first velocity in the horizontal direction and the second velocity in the vertical direction are determined respectively. Here, at each droplet measurement point, n effective droplets can be covered and collected. When collecting, the phase Doppler particle analyzer also synchronously collects the two-dimensional velocity vector of the droplet, that is, the first velocity of the droplet in the horizontal direction and the second velocity in the vertical direction , where i represents the i-th droplet.

[0032] Then, at each droplet measurement point, the theoretical spray kinetic energy of each droplet is calculated according to the first velocity and the second velocity. However, when calculating, it is necessary to calculate the resultant velocity and the second velocity first according to the first velocity , that is . Then, the theoretical spray kinetic energy is calculated. Then, the theoretical spray kinetic energy is weighted and calculated through the position weight to obtain the actual spray kinetic energy of the droplet, denoted as , and the formula is as follows: (3) In the above formula (3), is the particle size of the droplet, and represent the velocity of the droplet in the horizontal direction and the velocity in the vertical direction respectively, is the density of the droplet liquid, is the position weight of the j-th droplet measurement point, and i represents the i-th droplet collected at the droplet measurement point.

[0033] Finally, the actual spray kinetic energies of each droplet measurement point are summed to obtain the total kinetic energy of the droplets when the pressure nozzle sprays. Here, that is, the actual spray kinetic energies of the 10 droplet measurement points are summed, and the obtained total kinetic energy of the droplets is denoted as , and the summation formula is as follows: (4) In the above formula (4), n represents the total number of droplets collected at the droplet measurement point, i represents the i-th droplet collected at the droplet measurement point, and j represents the j-th droplet measurement point.

[0034] Of course, in actual implementation, the actual spray kinetic energy calculated for each droplet measurement point may have different values. Here, a kinetic energy distribution histogram can be generated based on the total droplet kinetic energy, and the standard deviation and coefficient of variation of the actual spray kinetic energy of m droplet measurement points can be calculated. To ensure the effectiveness of the calculation of the actual spray kinetic energy, the RANSA algorithm is used to eliminate outliers (such as eliminating the actual spray kinetic energy of environmental interference particles such as non-droplets) to ensure the effectiveness of the droplet sampling data and the accuracy of the calculation of the total droplet kinetic energy.

[0035] In the embodiment of the present invention, when calculating the kinetic energy of droplets at a droplet measurement point, different position weights are set according to the distance between the droplet measurement point and the pressure nozzle to calculate the kinetic energy, thereby effectively eliminating the influence of the spatial resistance encountered by the droplets in the process after spraying on the kinetic energy of the droplets.

[0036] Step 102: Obtain the inlet flow rate of the liquid inside the pressure nozzle pipeline and the nozzle flow rate at the nozzle.

[0037] After calculating the total kinetic energy of the droplets of the pressure nozzle spray through the above steps, it is necessary to determine the initial energy inside the nozzle at the pressure nozzle level. This initial energy is affected by the cavity pressure of the pressure nozzle. To calculate the cavity pressure, it is necessary to obtain the inlet flow rate of the liquid inside the pressure nozzle pipeline and the nozzle flow rate at the nozzle. Both flow rates can be calculated through the liquid flow rate inside the pressure nozzle and the cross-sectional area of ​​the corresponding nozzle, as described below.

[0038] First, obtain the liquid flow inside the pressure nozzle collected by the electromagnetic flowmeter, such as Figure 2 As shown in the figure, an electromagnetic flowmeter is installed in the pipeline of the pressure nozzle, which can collect the liquid flow inside the pressure nozzle in real time, recorded as Q. In addition, the inlet cross-sectional area and nozzle cross-sectional area of ​​the pressure nozzle need to be calculated separately. The pressure nozzle has an inlet for liquid to flow into the pipeline and an outlet for spraying. Assuming that the cross-sections of the inlet and outlet are regular circles, the inlet diameter is and outlet diameter All of these can be obtained based on the physical parameters or measurements of the pressure nozzle. The inlet cross-sectional area can be easily calculated based on the diameter. and nozzle cross-sectional area .

[0039] Finally, the inlet and outlet flow rates are calculated based on the liquid flow rate Q and the corresponding cross-sectional area. That is, the ratio of the liquid flow rate to the inlet cross-sectional area is used as the inlet flow rate of the liquid inside the pressure nozzle pipeline, which is recorded as , and the ratio of the liquid flow rate to the nozzle cross-sectional area is taken as the nozzle velocity of the liquid at the nozzle of the pressure nozzle, recorded as , the formula is as follows: (5) (6) In the embodiment of the present invention, the flow velocity at the inlet and outlet is calculated by the liquid flow rate collected in real time and the cross-sectional areas of the inlet and outlet, which is used to characterize the velocity of the liquid inside the pressure nozzle and lay a foundation for calculating the cavity pressure of the pressure nozzle subsequently.

[0040] Step 103: Calculate the cavity pressure of the pressure nozzle according to the inlet flow velocity and the nozzle flow velocity.

[0041] After obtaining the inlet flow velocity and the nozzle flow velocity of the pressure nozzle through the above Step 102, next, by using the conservation of the internal pressure and the outlet pressure of the pressure nozzle pipeline, the modified Bernoulli equation is fitted. This process is carried out under the conditions that the liquid is assumed to be an incompressible fluid and the flow is in a steady state. And due to the existence of pressure loss, the Bernoulli equation of pressure conservation needs to be modified, and finally the modified Bernoulli equation under pressure loss is fitted. By solving the modified Bernoulli equation, the cavity pressure of the pressure nozzle is calculated.

[0042] Specifically, first, it is necessary to determine the pressure loss during the flow of the liquid in the pressure nozzle pipeline. The pressure loss includes the frictional loss determined by the Darcy friction coefficient and the local loss determined by the local loss coefficient. The frictional loss and the local loss The calculation formulas are as follows respectively: (7) (8) In the above formulas (7) and (8), f is the Darcy friction coefficient, is the local loss coefficient, both of which can be obtained by querying the manual. L is the cavity length of the pressure nozzle, represents the hydraulic diameter inside the pressure nozzle pipeline, represents the average flow velocity of the liquid inside the pressure nozzle pipeline, is the composite velocity fitted according to the inlet flow velocity and the outlet flow velocity, is the density of the liquid, that is, the density of the droplet liquid.

[0043] The pressure loss during the flow of the liquid in the pressure nozzle pipeline is the sum of the frictional loss and the local loss , denoted as .

[0044] Next, the modified Bernoulli equation is constructed by using the conservation of the internal pressure and the outlet pressure of the pressure nozzle pipeline. On the one hand, according to the pipeline pressure of the pressure nozzle and the inlet flow velocity , calculate the total inlet pressure of the pressure nozzle. As Figure 2 shown, the pipeline pressure can be measured in real time by using a high-frequency pressure sensor installed in the pipeline of the pressure nozzle. The sampling rate of the high-frequency pressure sensor is set to be not less than 1 kHz. On the other hand, according to the unknown outlet pressure of the pressure nozzle, the nozzle flow velocity, and the pressure loss, determine the total nozzle pressure of the pressure nozzle. The outlet pressure of the pressure nozzle is usually the atmospheric pressure, that is, the gauge pressure is 0, and the unknown outlet pressure here in the embodiment of the present invention is the cavity pressure of the pressure nozzle to be calculated. Then, based on the total inlet pressure and the total nozzle pressure, a modified Bernoulli equation is constructed as follows: (9) In the above formula (9), the left side of the equal sign is the total inlet pressure of the pressure nozzle, and the right side of the equal sign is the total nozzle pressure. The equality of the left and right sides represents the conservation of the internal pressure and the outlet pressure of the pressure nozzle pipeline, that is, the modified Bernoulli equation is constructed therefrom.

[0045] Finally, solve the modified Bernoulli equation, and use the obtained unknown outlet pressure as the cavity pressure of the pressure nozzle, denoted as . Since there is only one unknown, the unknown outlet pressure of the pressure nozzle, in the above formula (9), by solving the above modified Bernoulli equation, we can obtain: (10) In the embodiment of the present invention, the Bernoulli equation is fitted by using the pressure conservation of the pressure nozzle, and the Bernoulli equation is modified under the pressure loss. Finally, the modified Bernoulli equation is used to solve for the cavity pressure of the pressure nozzle, so that the pressure value in the cavity of the pressure nozzle can be accurately calculated, which is convenient for further calculating the initial energy subsequently.

[0046] Step 104: Calculate the initial energy of the pressure nozzle under the weighted volume based on the cavity pressure, the inlet flow velocity, and the total volume of the droplets, and use the ratio of the total kinetic energy of the droplets to the initial energy as the atomization performance index of the pressure nozzle.

[0047] The initial energy of the liquid in the nozzle cavity is generally the initial energy of the liquid at the cavity of the pressure nozzle, that is, the liquid energy before spraying. In an ideal case, this liquid energy includes two parts: pressure energy and kinetic energy. The pressure energy can be calculated by the product of the pipeline pressure measured in real time by the high-frequency pressure sensor and the liquid flow rate Q, and the kinetic energy is calculated according to the inlet flow velocity and the liquid flow rate Q, that is , but due to the influence of pressure loss and only a part of the sprayed liquid, it is necessary to calculate this initial energy in combination with the total volume of the sprayed liquid. Therefore, in the embodiments of the present invention, the total volume of the droplets is used to calculate the initial energy of the pressure nozzle, that is, the initial energy of the pressure nozzle under the weighted volume.

[0048] The initial energy under the weighted volume still consists of two parts: pressure energy and liquid kinetic energy. The first distribution is based on the inlet flow rate and the total volume of the droplets , to calculate the inlet kinetic energy of the liquid inside the pressure nozzle. The second part is based on the cavity pressure and the total volume of the droplets , to calculate the pressure energy of the liquid inside the pressure nozzle. Finally, the energies of the two parts are summed up, that is, the inlet kinetic energy and the pressure energy are summed up, to obtain the initial energy corresponding to the weighted volume inside the pressure nozzle, denoted as , expressed as: (11) In the embodiments of the present invention, the internal pressure energy and the inlet kinetic energy of the pressure nozzle are respectively calculated through the total volume of the droplets, so as to accurately characterize the initial energy of the liquid to be sprayed before spraying, facilitate the direct calculation of the atomization performance index of the pressure nozzle, and realize the evaluation of the spraying performance of the pressure nozzle.

[0049] Finally, the ratio of the total kinetic energy of the droplets to the initial energy is used as the atomization performance index of the pressure nozzle. The total kinetic energy of the droplets characterizes the energy of the liquid after spraying, while the initial energy is the energy inside the pressure nozzle before the liquid is sprayed. Therefore, the ratio of the two can be used as an index to measure the atomization performance and is used to evaluate the spraying performance of the pressure nozzle. The calculation formula of the atomization performance is as follows: (12) In the above formula (12), represents the particle size of the i-th droplet collected at the j-th droplet measurement point, represents the combined velocity of the i-th droplet collected at the j-th droplet measurement point. The combined velocity is the square sum of the velocity in the horizontal direction and the velocity in the vertical direction. The explanations of the remaining parameters can all refer to the above formulas (3), (4), (11), and will not be elaborated here. By simplifying the above formula (12), we have: (13) The atomization performance of the pressure nozzle can be used to evaluate the spraying performance of the pressure nozzle. The higher the atomization performance, the better the spraying performance of the pressure nozzle, and vice versa. Of course, the atomization performance index calculated by the above formula (12) is for the atomization performance index of tap water spraying. According to actual needs, the above method of the embodiments of the present invention can also be used to calculate the atomization performance indexes of other liquid solutions such as pesticides and plant liquids, or for specific liquids, calculate the atomization performance indexes of the pressure nozzle under different nozzle types, such as fan nozzles and conical nozzles. Thus, the influence of different liquids or different nozzle types on the atomization performance can be determined, so as to comprehensively evaluate the spraying performance of the pressure nozzle.

[0050] In the embodiments of the present invention, the atomization performance index is calculated by calculating the initial energy and the total kinetic energy of the droplets under the weighted volume of the pressure nozzle. As a comprehensive evaluation index for evaluating the pressure nozzle, it can comprehensively reflect the spraying performance of the pressure nozzle, provide strong support for the optimal design and selection of the pressure nozzle, and the comprehensive evaluation index can be applied to the spraying performance evaluation of different types of pressure nozzles, having good universality.

[0051] The atomization performance evaluation device of the pressure nozzle provided by the present invention will be described below. The atomization performance evaluation device of the pressure nozzle described below can be correspondingly referred to the atomization performance evaluation method of the pressure nozzle described above.

[0052] As Figure 3 shown, the atomization performance evaluation device of the pressure nozzle specifically includes: a determination module 301, an acquisition module 302, a calculation module 303, and an evaluation module 304. Specifically, the determination module 301 is used to determine the total volume of the droplets and the total kinetic energy of the droplets when the pressure nozzle sprays; the acquisition module 302 is used to acquire the inlet flow rate of the liquid inside the pressure nozzle pipe and the nozzle flow rate at the nozzle; the calculation module 303 is used to calculate the cavity pressure of the pressure nozzle according to the inlet flow rate and the nozzle flow rate; the evaluation module 304 is used to calculate the initial energy of the pressure nozzle under the weighted volume based on the cavity pressure, the inlet flow rate, and the total volume of the droplets, and use the ratio of the total kinetic energy of the droplets to the initial energy as the atomization performance index of the pressure nozzle.

[0053] It should be noted that the beneficial effects of the atomization performance evaluation device of the pressure nozzle here and the atomization performance evaluation method of the pressure nozzle above can correspond to each other. Therefore, the beneficial effects of the atomization performance evaluation device of the pressure nozzle will not be elaborated here.

[0054] Figure 4 Illustrated is a schematic diagram of the physical structure of an electronic device, as Figure 4As shown in the figure, the electronic device may include: a processor 410, a communications interface 420, a memory 430, and a communication bus 440. Among them, the processor 410, the communications interface 420, and the memory 430 communicate with each other through the communication bus 440. The processor 410 may call the logical instructions in the memory 430 to execute the atomization performance evaluation method of the pressure nozzle. The method includes: determining the total volume of droplets and the total kinetic energy of droplets when the pressure nozzle sprays; obtaining the inlet flow rate of the liquid inside the pressure nozzle pipeline and the nozzle flow rate at the nozzle; calculating the cavity pressure of the pressure nozzle according to the inlet flow rate and the nozzle flow rate; calculating the initial energy of the pressure nozzle under the weighted volume based on the cavity pressure, the inlet flow rate, and the total volume of droplets, and taking the ratio of the total kinetic energy of the droplets to the initial energy as the atomization performance index of the pressure nozzle.

[0055] In addition, when the logical instructions in the above-mentioned memory 430 are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The foregoing storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), magnetic disks, or optical discs that can store program codes.

[0056] On the other hand, the present invention also provides a computer program product. The computer program product includes a computer program. The computer program can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the atomization performance evaluation method of the pressure nozzle provided by the above-mentioned various methods. The method includes: determining the total volume of droplets and the total kinetic energy of droplets when the pressure nozzle sprays; obtaining the inlet flow rate of the liquid inside the pressure nozzle pipeline and the nozzle flow rate at the nozzle; calculating the cavity pressure of the pressure nozzle according to the inlet flow rate and the nozzle flow rate; calculating the initial energy of the pressure nozzle under the weighted volume based on the cavity pressure, the inlet flow rate, and the total volume of droplets, and taking the ratio of the total kinetic energy of the droplets to the initial energy as the atomization performance index of the pressure nozzle.

[0057] In another aspect, the present invention also provides a non-transitory computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it implements the method for evaluating the atomization performance of a pressure nozzle provided by the above-mentioned various methods. The method includes: determining the total volume of droplets and the total kinetic energy of droplets when the pressure nozzle sprays; obtaining the inlet flow rate of the liquid inside the pressure nozzle pipeline and the nozzle flow rate at the nozzle; calculating the cavity pressure of the pressure nozzle according to the inlet flow rate and the nozzle flow rate; calculating the initial energy of the pressure nozzle under the weighted volume based on the cavity pressure, the inlet flow rate, and the total volume of droplets, and taking the ratio of the total kinetic energy of the droplets to the initial energy as the atomization performance index of the pressure nozzle.

[0058] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. Those of ordinary skill in the art can understand and implement it without creative labor.

[0059] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the essence of the above technical solution, or the part that contributes to the prior art, can be embodied in the form of a software product. The computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or equivalently replace some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for evaluating the atomization performance of a pressure nozzle, characterized in that: include: Determine the total volume of droplets and the total kinetic energy of droplets when the pressure nozzle is spraying; Obtaining the inlet flow rate of the liquid inside the pressure nozzle pipeline and the nozzle flow rate at the nozzle; Calculating the cavity pressure of the pressure nozzle according to the inlet flow rate and the nozzle flow rate; The initial energy of the pressure nozzle under the weighted volume is calculated based on the cavity pressure, the inlet flow rate and the total volume of the droplets, and the ratio of the total kinetic energy of the droplets to the initial energy is used as the atomization performance index of the pressure nozzle.

2. The method for evaluating the atomization performance of a pressure nozzle according to claim 1, characterized in that: The process of determining the total volume of droplets when the pressure nozzle is spraying includes: When the pressure nozzle is spraying, the particle size of a single droplet collected by a phase Doppler particle analyzer is obtained, and the volume of the single droplet is calculated according to the particle size; Determine the total number of droplets during spraying according to the number of effective droplets collected at the droplet measurement points within the spray width, wherein the droplet measurement points are evenly distributed within the spray width; The volumes of individual droplets of the total number of droplets are summed to obtain the total volume of droplets when the pressure nozzle is spraying.

3. The method for evaluating the atomization performance of a pressure nozzle according to claim 1, characterized in that: The process of determining the total kinetic energy of droplets when the pressure nozzle sprays includes: Within the spray width range of the spray, a corresponding position weight is assigned to each droplet measurement point, wherein the position weight of each droplet measurement point is negatively correlated with the actual distance from the pressure nozzle; After the pressure nozzle sprays, for each droplet collected at the droplet measurement point, a first velocity in the horizontal direction and a second velocity in the vertical direction are determined respectively; At each droplet measurement point, the theoretical spray kinetic energy of each droplet is calculated according to the first speed and the second speed, and the theoretical spray kinetic energy is weightedly calculated by a position weight to obtain an actual spray kinetic energy of the droplet; The actual spray kinetic energy of each droplet measurement point is summed to obtain the total kinetic energy of the droplets when the pressure nozzle is spraying.

4. The method for evaluating the atomization performance of a pressure nozzle according to claim 1, characterized in that: The method of obtaining the inlet flow rate of the liquid inside the pressure nozzle pipeline and the nozzle flow rate at the nozzle comprises: Obtain the liquid flow inside the pressure nozzle collected by the electromagnetic flowmeter; Calculate the inlet cross-sectional area and nozzle cross-sectional area of ​​the pressure nozzle respectively; The ratio of the liquid flow rate to the inlet cross-sectional area is used as the inlet flow rate of the liquid inside the pressure nozzle pipeline, and the ratio of the liquid flow rate to the nozzle cross-sectional area is used as the nozzle flow rate of the liquid at the nozzle of the pressure nozzle.

5. The method for evaluating the atomization performance of a pressure nozzle according to claim 1, characterized in that: The step of calculating the cavity pressure of the pressure nozzle according to the inlet flow rate and the nozzle flow rate comprises: Determine the pressure loss of the liquid during the flow in the pressure nozzle pipeline, wherein the pressure loss includes the friction loss determined by the Darcy friction coefficient and the local loss determined by the local loss coefficient; Calculating the total inlet pressure of the pressure nozzle according to the pipeline pressure of the pressure nozzle and the inlet flow rate, and determining the total nozzle pressure of the pressure nozzle according to the unknown outlet pressure of the pressure nozzle, the nozzle flow rate and the pressure loss; Constructing a modified Bernoulli equation based on the inlet total pressure and the nozzle total pressure; The modified Bernoulli equation is solved, and the unknown outlet pressure obtained by the solution is used as the cavity pressure of the pressure nozzle.

6. The method for evaluating the atomization performance of a pressure nozzle according to claim 1, characterized in that: The calculating the initial energy of the pressure nozzle under the weighted volume based on the cavity pressure, the inlet flow rate and the total volume of the droplets comprises: Calculating the inlet kinetic energy of the liquid inside the pressure nozzle according to the inlet flow rate and the total volume of the droplets; Calculating the pressure energy of the liquid inside the pressure nozzle according to the cavity pressure and the total volume of the droplets; The inlet kinetic energy and the pressure energy are summed to obtain the initial energy of the corresponding weighted volume inside the pressure nozzle.

7. A device for evaluating the atomization performance of a pressure nozzle, characterized in that: include: A determination module, used to determine the total volume of droplets and the total kinetic energy of droplets when the pressure nozzle is spraying; An acquisition module, used for acquiring the inlet flow rate of the liquid inside the pressure nozzle pipeline and the nozzle flow rate at the nozzle; A calculation module, used for calculating the cavity pressure of the pressure nozzle according to the inlet flow rate and the nozzle flow rate; An evaluation module is used to calculate the initial energy of the pressure nozzle under the weighted volume based on the cavity pressure, the inlet flow rate and the total volume of the droplets, and use the ratio of the total kinetic energy of the droplets to the initial energy as the atomization performance index of the pressure nozzle.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that: When the processor executes the computer program, the atomization performance evaluation method of the pressure nozzle according to any one of claims 1 to 6 is implemented.

9. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the atomization performance evaluation method of the pressure nozzle according to any one of claims 1 to 6 is implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the atomization performance evaluation method of the pressure nozzle according to any one of claims 1 to 6 is implemented.

Images