Method for quickly and accurately calculating flow distribution area of plunger pump

Abstract

A method for quickly and accurately calculating the flow area of a plunger pump, comprising: 1) extracting the flow passage model of the flow area of the plunger pump, including the oil suction, oil discharge and cylinder hole flow passages, and the oil suction and oil discharge flow passages each including a waist-shaped groove and a triangular damping groove; 2) point cloud processing of the flow passage model; 3) identifying the profile of the flow passage point cloud model and dividing the oil suction and oil discharge flow passage point cloud models into different sub-flow passage areas; 4) calculating the flow area of the different sub-flow passage point cloud models by the point cloud sweeping method, keeping the sub-flow passage point cloud model still and rotating the cylinder hole flow passage point cloud model around the center of the sub-flow passage point cloud model to calculate the interaction area in real time; and 5) verifying the calculation result of the flow area. The user does not need to derive theoretical calculation formulas and set complex parameters, but only needs to extract the flow passage model of the flow area of the plunger pump, and the flow area of any flow structure with irregular shapes such as round corners, chamfers and reinforcing ribs can be calculated, which is simple to operate, high in calculation precision and speed, and strong in practicality.

Description

Technical Field

[0001] This invention relates to the field of hydraulic pumps, and more particularly to a method for rapidly and accurately calculating the flow distribution area of ​​a plunger pump. Background Technology

[0002] The flow distribution mechanism is a crucial component of hydraulic pump design. Its primary function is to separate the pump's suction and discharge chambers, and to control the intake and discharge of hydraulic fluid based on the rotor's rotation direction and angle. The design of a plunger pump's flow distribution mechanism mainly involves determining parameters such as the shape of the flow distribution windows on the distribution plate, their opening angles, and the structure of the unloading grooves. These parameters directly affect the plunger pump's performance indicators, including flow rate, pressure, efficiency, and noise. Therefore, a well-designed flow distribution mechanism is key to improving the performance and stability of the plunger pump. The flow distribution area refers to the sum of the areas of the windows on the distribution plate that connect to either the suction or discharge chamber at any given time. It is one of the main parameters reflecting the quality of the flow distribution mechanism design. Accurately calculating the flow distribution area is fundamental to the forward design of the flow distribution mechanism and a prerequisite for simulating the plunger pump's operating characteristics and optimizing the flow distribution mechanism parameters.

[0003] Currently, there are two main methods for calculating the distribution area: geometric calculation and numerical simulation. Geometric calculation calculates the distribution area based on the geometric dimensions of the distribution plate and distribution channel, using mathematical formulas for regular geometric shapes with similar forms. Numerical simulation uses computational fluid dynamics (CFD) software to create a three-dimensional model of the plunger pump's distribution region and perform numerical solutions to obtain the velocity and pressure distribution of the oil in the channel, thereby calculating the distribution area. However, both methods have limitations. Geometric calculation requires deriving complex mathematical formulas, resulting in a cumbersome calculation process, and it cannot be applied to complex distribution structures with irregular shapes such as rounded corners, chamfers, and reinforcing ribs. Numerical simulation requires substantial computational resources and specialized fluid dynamics knowledge, and the calculation time is relatively long. Summary of the Invention

[0004] The purpose of this invention is to solve the above-mentioned problems in the prior art and provide a method for fast and accurate calculation of the flow distribution area of ​​a plunger pump. This method can improve the calculation speed while ensuring calculation accuracy, simplify the calculation process, and enhance the practicality and applicability of engineering.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A method for quickly and accurately calculating the flow distribution area of ​​a plunger pump is proposed, including the following steps:

[0007] 1) Extract the flow channel model of the plunger pump distribution area. The flow channel model includes the oil suction channel, the oil discharge channel and the cylinder bore channel. The oil suction channel and the oil discharge channel both include waist-shaped grooves and triangular damping grooves.

[0008] 2) The flow channel model is processed into a point cloud to generate a flow channel point cloud model of the distribution area. The number of points can be actively adjusted according to the structure of the distribution disk.

[0009] 3) Identify the outline of the flow channel point cloud model, and divide the point cloud models of the oil suction channel and oil discharge channel into different sub-flow channel regions in a clockwise or counterclockwise direction using the point cloud distance method, point cloud coordinate method or point cloud angle method;

[0010] 4) The point cloud sweeping method is used to calculate the flow distribution area of ​​different sub-flow channel point cloud models. During the sweeping, the sub-flow channel point cloud model remains stationary, while the cylinder bore flow channel point cloud model rotates around the center of the sub-flow channel point cloud model at certain angular intervals. During this process, the interaction area between the two is calculated in real time.

[0011] 5) Verify the distribution area calculation results. If the accuracy meets the set requirements, output the calculated distribution area directly; otherwise, return to step 2) to regenerate the point cloud model.

[0012] Furthermore, in step 3), the division into several regions is done as follows: calculate the distance between any two adjacent point clouds; if the distance between the two point clouds is less than 1mm, they are divided into the same region; otherwise, they are divided into different regions.

[0013] Furthermore, in step 3), it is necessary to adjust the edge contour recognition coefficient of the distribution area so that the recognized contour conforms to the shape of the actual distribution area.

[0014] Furthermore, in step 4), the angle is 0.5° to 2°.

[0015] Furthermore, in step 4), when calculating the flow distribution area of ​​the waist-shaped groove, the cylinder bore contour is rotated around the center of the waist-shaped groove contour, and the intersection area of ​​the two contours is calculated in real time during this process.

[0016] Furthermore, in step 4), when calculating the area of ​​the triangular damping groove, the streamlines are first identified based on the coordinate characteristics of the height direction of the triangular damping groove. Assuming the intersection of the lower surface profile of the cylinder bore and the upper surface profile of the triangular damping groove at a certain rotation angle is a set of points ab, the streamlines are iterated through any three adjacent points ab on the intersection line. i-1 ab i and ab i+1 any three points c adjacent to the streamline i-1 c i and c i+1 Composed of polygon S abc (i-1), S abc (i) and S abc (i+1):

[0017]

[0018] Using points on the streamline of the triangular damping groove as stepping points, calculate the area of ​​each polygon. Then, the flow distribution area of ​​the triangular damping groove is the minimum value of the areas of all polygons.

[0019] S = min(S n-1 ,S n ,S n+1 )

[0020] Furthermore, in step 5), the calculation results of the distribution area are verified, and the comparison objects include the calculation results of geometric calculation method or numerical simulation method.

[0021] Compared with the prior art, the beneficial effects achieved by the technical solution of this invention are:

[0022] This invention extracts the flow channel model of the distribution area of ​​a plunger pump, and can calculate the distribution area of ​​any distribution disk with a series of irregular structures such as rounded corners, chamfers, and reinforcing ribs. The calculation accuracy is comparable to that of geometric calculation methods and numerical simulation methods. However, compared with geometric calculation methods, it omits tedious theoretical formula derivation and complex calculation parameter settings, making the operation simpler. Compared with numerical simulation methods, it reduces a lot of calculation time and is more practical. Attached Figure Description

[0023] Figure 1 This is a flowchart illustrating the steps of a method for rapidly and accurately calculating the flow distribution area of ​​a plunger pump according to the present invention.

[0024] Figure 2 This invention provides a method for quickly and accurately calculating the flow distribution area of ​​a plunger pump. The flow distribution plate structure used in this case is shown in the diagram.

[0025] Figure 3 This invention provides a method for rapidly and accurately calculating the flow distribution area of ​​a plunger pump, along with a point cloud model of the flow distribution area and a schematic diagram of the area division.

[0026] Figure 4 This is a schematic diagram illustrating the method for quickly and accurately calculating the distribution area of ​​a plunger pump according to the present invention, specifically the calculation of the distribution area of ​​a waist-shaped groove.

[0027] Figure 5 This is a schematic diagram illustrating the method for quickly and accurately calculating the flow distribution area of ​​a plunger pump according to the present invention, using a triangular damping groove.

[0028] Figure 6 This is a comparison chart of the distribution area of ​​the waist-shaped groove calculated by the method of rapid and accurate calculation of the distribution area of ​​the plunger pump of the present invention and the distribution area obtained by the geometric calculation method.

[0029] Figure 7 This is a comparison chart of the triangular damping groove distribution area calculated by the method for rapid and accurate calculation of the distribution area of ​​a plunger pump according to the present invention and the distribution area obtained by the CFD method.

[0030] The attached diagram is labeled as follows: 1 is the outer dead point, 2 is the inner dead point, 3 is the waist-shaped groove of the oil suction area, 4 is the triangular damping groove of the oil suction area, 5-9 are the waist-shaped grooves of the oil discharge area, and 10 is the triangular damping groove of the oil discharge area. Detailed Implementation

[0031] To make the technical problems, technical solutions and beneficial effects of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0032] See Figure 1 The flowchart illustrates a method for rapidly and accurately calculating the flow distribution area of ​​a plunger pump. First, in 3D software, the flow distribution area channel is extracted using a combined feature command. Then, the flow distribution area channel entity is processed into a point cloud, and the outline of the point cloud is identified. Next, the cylinder bore is rotated 360° along the flow distribution area to obtain the complete interactive area, and the calculation results are verified. Finally, the calculation results are evaluated. If the calculation results meet the requirements, the calculation results are directly output; otherwise, the point cloud model is readjusted and the calculation is performed again.

[0033] See Figure 2 The diagram illustrates an example of a rapid and accurate calculation method for the distribution area of ​​a plunger pump, using a distribution plate structure. In this embodiment, the distribution plate is divided into an oil suction region and an oil discharge region by an outer dead point 1 and an inner dead point 2. The oil suction region consists of a waist-shaped groove 3 and a triangular damping groove 4, while the oil discharge region is divided into five independent areas, including waist-shaped grooves 5-9 and a triangular damping groove 10. The size and shape of the triangular damping groove 4 in the oil suction region and the triangular damping groove 10 in the oil discharge region are identical. It is noteworthy that these triangular damping grooves are not strictly located on the pitch circle of the distribution plate, and a certain size of fillet is provided at the bottom for ease of machining.

[0034] See Figure 3 This diagram illustrates a method for quickly and accurately calculating the distribution area of ​​a plunger pump, along with a point cloud model and region division diagram of the distribution area. In this implementation, the number of point clouds is set to 2000, and the point cloud distance method is used to divide the distribution area. Figure 3 Figure a) shows the waist-shaped channel distribution area divided into sub-regions I to VI. Figure 3 (b) Figure 3 The flow distribution region of the angular damping groove is divided into two sub-regions, I and II.

[0035] See Figure 4The diagram illustrates a method for quickly and accurately calculating the distribution area of ​​a plunger pump, specifically a schematic diagram of the waist-shaped groove distribution area calculation. The cylinder bore is rotated around the center of the distribution plate's pitch circle at 1° intervals, and the intersection area of ​​the cylinder bore and the waist-shaped groove is calculated in real time during this process. Since the accuracy of the distribution area contour recognition significantly affects the final calculation result, it is necessary to reasonably adjust the edge contour coefficient to ensure that the fitted contour conforms to the actual shape of the distribution plate.

[0036] See Figure 5 The diagram illustrates a method for quickly and accurately calculating the flow distribution area of ​​a plunger pump, specifically a schematic diagram of a triangular damping groove. First, streamlines are identified based on the height-direction coordinate characteristics of the triangular damping groove. Assuming the intersection of the lower surface profile of the cylinder bore and the upper surface profile of the triangular groove at a certain rotation angle is a set of points ab, the process iterates through any three adjacent points ab on the intersection line. i-1 ab i and ab i+1 any three points c adjacent to the streamline i-1 c i and c i+1 Composed of polygon S abc (i-1), S abc (i) and S abc (i+1):

[0037]

[0038] Using the points on the streamline of the triangular groove as stepping points, calculate the area of ​​each polygon. Then, the flow distribution area of ​​the triangular groove is the minimum value of the areas of all polygons.

[0039] S = min(S n-1 ,S n ,S n+1 (2)

[0040] See Figure 6 The figure shows a comparison between the distribution area of ​​the waist-shaped groove calculated by a method for rapid and accurate calculation of the distribution area of ​​a plunger pump and the distribution area obtained by the geometric calculation method. It can be observed from the figure that the starting and ending angles of the waist-shaped groove distribution area obtained by the geometric method and the method of this invention are the same. Specifically, the starting angle of the oil suction zone is 7.6° and the ending angle is 172.3°; the starting angle of the oil discharge zone is 178.6° and the ending angle is 352.3°. The maximum oil suction distribution area calculated by the geometric method is 151.7 mm². 2 The maximum oil absorption and distribution area of ​​the method of this invention is 150.5 mm. 2 Similarly, the oil drainage area calculated by both methods reaches its maximum value at the third small oblong orifice, with the geometric method yielding a maximum drainage area of ​​108 mm². 2The maximum oil discharge distribution area of ​​the method of this invention is 107.2 mm. 2 Calculations show that the error between the method of this invention and the geometric method is within 1%, indicating that the method proposed in this invention has high computational accuracy.

[0041] See Figure 7 The diagram shows a comparison between the triangular damping groove distribution area calculated by a method for rapid and accurate calculation of the distribution area of ​​a plunger pump and the distribution area obtained by the CFD method. The calculation results of the method and the CFD method generally show a consistent trend, with the CFD method calculating a maximum triangular damping groove distribution area of ​​2.35 mm. 2 The method of this invention calculates the maximum flow distribution area of ​​the triangular damping groove to be 2.30 mm. 2 The error between the two methods is 2.1%. There are some differences between the two methods in the middle section, which may be due to the inability to accurately determine parameters such as oil density, elastic modulus, and flow coefficient in the CFD method during simulation, and the smaller number of point clouds in the method of this invention. Calculations show that the calculation error between the method of this invention and the geometric method is 2.1%. The calculation time of the method of this invention is 114 seconds, while that of the CFD method is 7 hours and 34 minutes, further demonstrating that the method proposed in this invention not only has higher calculation accuracy but also significantly reduces calculation time.

[0042] It is understood that, although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents. Any non-substantial modifications made to the present invention using this concept shall be considered an infringement of the scope of protection of the present invention.

Claims

1. A method for rapidly and accurately calculating the flow distribution area of ​​a plunger pump, characterized in that, Includes the following steps: 1) Extract the flow channel model of the plunger pump distribution area. The flow channel model includes the oil suction channel, the oil discharge channel and the cylinder bore channel. The oil suction channel and the oil discharge channel both include waist-shaped grooves and triangular damping grooves. 2) The flow channel model is processed into point cloud to generate a flow channel point cloud model of the distribution area. The number of point clouds can be actively adjusted according to the structure of the distribution disk. 3) Identify the outline of the flow channel point cloud model, and divide the point cloud models of the oil suction channel and oil discharge channel into different sub-flow channel regions in a clockwise or counterclockwise direction using the point cloud distance method, point cloud coordinate method or point cloud angle method; 4) The point cloud sweeping method is used to calculate the flow distribution area of ​​different sub-flow channel point cloud models. During the sweeping, the sub-flow channel point cloud model remains stationary, while the cylinder bore flow channel point cloud model rotates around the center of the sub-flow channel point cloud model at certain angular intervals. During this process, the interaction area between the two is calculated in real time. 5) Verify the distribution area calculation results. If the accuracy meets the set requirements, output the calculated distribution area directly; otherwise, return to step 2) to regenerate the point cloud model.

2. The method for rapidly and accurately calculating the flow distribution area of ​​a plunger pump as described in claim 1, characterized in that: In step 3), the division into different sub-channel regions is as follows: calculate the distance between any two adjacent point clouds. If the distance between the two point clouds is less than 1mm, they are divided into the same region; otherwise, they are divided into different regions.

3. The method for rapidly and accurately calculating the flow distribution area of ​​a plunger pump as described in claim 1, characterized in that: In step 3), it is necessary to adjust the edge contour recognition coefficient of the distribution area so that the recognized contour conforms to the shape of the actual distribution area.

4. The method for rapidly and accurately calculating the flow distribution area of ​​a plunger pump as described in claim 1, characterized in that: In step 4), the angle is 0.5° to 2°.

5. The method for rapidly and accurately calculating the flow distribution area of ​​a plunger pump as described in claim 1, characterized in that: In step 4), when calculating the flow distribution area of ​​the waist-shaped groove, the cylinder bore contour is rotated around the center of the waist-shaped groove contour, and the intersection area of ​​the two contours is calculated in real time during this process.

6. The method for rapidly and accurately calculating the flow distribution area of ​​a plunger pump as described in claim 1, characterized in that: In step 4), when calculating the area of ​​the triangular damping groove, the streamlines are first identified based on the coordinate characteristics of the height direction of the triangular damping groove. Assuming the intersection of the lower surface profile of the cylinder bore and the upper surface profile of the triangular damping groove at a certain rotation angle is a set of points ab, the streamlines are iterated through any three adjacent points ab on the intersection line. i-1 ab i and ab i+1 any three points c adjacent to the streamline i-1 c i and c i+1 Composed of polygon S abc (i-1), S abc (i) and S abc (i+1): Using points on the streamline of the triangular damping groove as stepping points, calculate the area of ​​each polygon. Then, the flow distribution area of ​​the triangular damping groove is the minimum value of the areas of all polygons. S=min(S n-1 ,S n ,S n+1 )。 7. The method for rapidly and accurately calculating the flow distribution area of ​​a plunger pump as described in claim 1, characterized in that: In step 5), the calculation results of the distribution area are verified, and the comparison objects include the calculation results of geometric calculation method or numerical simulation method.

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