Method and system for predicting pressure drop loss of rotary ball valve under pulsating flow

Abstract

Disclosed in the present invention are a method and system for predicting a pressure drop loss of a rotary ball valve under a pulsating flow. The method comprises: establishing an equivalent model of a rotary O-shaped ball valve flow channel, wherein the equivalent model comprises four throttling elements, i.e., a thick orifice plate, thin orifice plates, a Z-shaped bent pipe, and upstream and downstream straight pipe sections at ball valve pressure measuring points; acquiring pulsating fluid speeds and pulsating instantaneous flow rates in the throttling elements, and on the basis of the pulsating fluid speeds and the pulsating instantaneous flow rates, calculating pulsating pressure drop losses corresponding to the throttling elements; and on the basis of the pulsating pressure drop losses of all the throttling elements, calculating the total pressure drop loss of a rotary ball valve under a pulsating flow. The method provided by the present invention can improve the calculation efficiency when the pressure drop loss is predicted.

Description

A method and system for predicting pressure drop loss of rotary ball valve under pulsating flow Technical Field

[0001] The present invention belongs to the technical field of ball valve design, and in particular relates to a method and system for predicting pressure drop loss of a rotary ball valve under pulsating flow. Background Art

[0002] As an important control element in hydraulic piping systems, ball valves are widely used in the petroleum, chemical, shipbuilding, pharmaceutical and other fields. They have the advantages of compact structure, low fluid resistance, and high flow capacity. There are many types of ball valves, and the most widely used ball valves in engineering are rotary O-type ball valves. Rotary O-type ball valves generally achieve fluid regulation and control by operating the valve handle to drive the valve core to rotate. Pressure drop is one of the key parameters required for ball valve design, directly affecting the operational stability and safety of the pipeline system where the ball valve is located, and it also forms the basis for calculating other fluid parameters of the valve. Improper valve pressure drop design can not only cause serious vibration and noise problems in the system, but can sometimes even lead to valve stem fracture, fatigue and other problems. Therefore, pressure drop calculation is very important for ball valve design.

[0003] Valve pressure drop is directly related to the flow state of the fluid passing through the valve. Fluid flow can be categorized as either stable, steady flow or unsteady, pulsating flow. The valve pressure drop characteristic under pulsating flow differs significantly from that under steady-state flow. It is no longer a constant value but varies with factors such as the pulsation frequency, amplitude, and velocity of the pulsating flow.

[0004] Currently, there are two methods for calculating the pulsating pressure drop loss of ball valves under pulsating flow: experimental methods and numerical simulation methods. Although numerical simulation and experimental analysis methods can provide accurate and reliable results, due to the complexity of the valve structure and the transient characteristics of the pulsating flow, the system has strong nonlinear characteristics. Numerical calculations are time-consuming, and the calculation results are greatly affected by numerical modeling, grid technology, and computational solution settings. Sometimes, they even fail to converge due to nonlinearity. In addition, experimental methods can indeed provide accurate and reliable results, but they are time-consuming and costly, and the experimental system is fixed in working conditions and has poor flexibility.

[0005] In summary, both numerical and experimental methods are at a semi-theoretical, semi-experimental stage, lacking a unified theoretical foundation. Furthermore, numerical calculations are time-consuming and cannot rapidly predict pressure drop losses. Consequently, current research on ball valves is insufficient, and theoretical research on their pulsating pressure drop remains unresolved, lacking a unified, universal theoretical prediction model for engineering reference. Therefore, it is crucial to establish a theoretical prediction model that can rapidly calculate the pressure drop losses of rotary O-type ball valves under pulsating flows.

[0006] Summary of the Invention

[0007] The present invention aims to at least partially address one of the technical problems in the related art. To this end, the present invention provides a method and system for predicting pressure drop loss in a rotary ball valve under pulsating flow, the primary purpose of which is to improve the computational efficiency of predicting pressure drop loss.

[0008] According to a first aspect of the present disclosure, a method for predicting pressure drop loss of a rotary ball valve under pulsating flow is provided, comprising:

[0009] An equivalent model of the flow passage of a rotary O-type ball valve is established, which includes four throttling elements: a thick orifice plate, a thin orifice plate, a Z-bend pipe, and straight pipe sections upstream and downstream of the ball valve pressure measurement point.

[0010] Obtaining the pulsating fluid velocity and the pulsating instantaneous flow rate in the throttling element, and calculating the pulsating pressure drop loss corresponding to each throttling element based on the pulsating fluid velocity and the pulsating instantaneous flow rate;

[0011] The total pressure drop loss of the rotary ball valve under pulsating flow is calculated based on the pulsating pressure drop loss of all throttling elements.

[0012] In the method for predicting the pressure drop loss of a rotary ball valve under pulsating flow provided in the first aspect disclosed in the present invention, the method for calculating the pulsating pressure drop loss of the upstream and downstream straight pipe sections includes: obtaining the instantaneous friction resistance coefficient of the pipeline, the inner diameter of the pipeline, the length of the pipeline, the fluid density and the pulsating fluid velocity of the upstream and downstream straight pipe sections, and then calculating the pulsating pressure drop loss of the upstream and downstream straight pipe sections.

[0013] In the method for predicting the pressure drop loss of a rotary ball valve under pulsating flow provided in the first aspect disclosed in the present invention, the method for calculating the pulsating pressure drop loss of the thick orifice plate includes: obtaining the pulsating instantaneous flow at the thick orifice plate and the pressure loss coefficient of the thick orifice plate, and then calculating the pulsating pressure drop loss of the thick orifice plate.

[0014] In the method for predicting the pressure drop loss of a rotary ball valve under pulsating flow provided in the first aspect disclosed in the present invention, the number of the thin orifice plates is 2, namely the first thin orifice plate and the second thin orifice plate; the method for calculating the pulsating pressure drop loss of the first thin orifice plate and the second thin orifice plate includes: obtaining the pulsating instantaneous flow at the first thin orifice plate and the pressure loss coefficient of the first thin orifice plate, and then calculating the pulsating pressure drop loss of the first thin orifice plate; obtaining the pulsating instantaneous flow at the second thin orifice plate and the pressure loss coefficient of the second thin orifice plate, and then calculating the pulsating pressure drop loss of the second thin orifice plate.

[0015] In the method for predicting the pressure drop loss of a rotary ball valve under pulsating flow provided in the first aspect disclosed in the present invention, the method for calculating the pulsating pressure drop loss of the Z-type bend includes: obtaining the local resistance coefficient of the Z-type bend at the sharp bend, the pulsating instantaneous flow rate of the Z-type bend and the cross-sectional area of ​​the ball valve inlet, and then calculating the pulsating pressure drop loss of the Z-type bend.

[0016] In the method for predicting the pressure drop loss of a rotary ball valve under pulsating flow provided in the first aspect disclosed in the present invention, the total pressure drop loss of the rotary ball valve under pulsating flow is calculated based on the pulsating pressure drop losses of all throttling elements, including: summing the pulsating pressure drop losses of all throttling elements to obtain the total pressure drop loss of the rotary ball valve under pulsating flow.

[0017] According to a second aspect of the present disclosure, a system for predicting pressure drop loss under pulsating flow of a rotary ball valve is provided, comprising:

[0018] A modeling module is used to establish an equivalent model of the flow channel of a rotary O-type ball valve, wherein the equivalent model includes four throttling elements: a thick orifice plate, a thin orifice plate, a Z-bend pipe, and a straight pipe section upstream and downstream of a pressure measuring point of the ball valve;

[0019] a throttling element pressure loss calculation module, configured to obtain the pulsating fluid velocity and the pulsating instantaneous flow rate in the throttling element, and calculate the pulsating pressure drop loss corresponding to each throttling element based on the pulsating fluid velocity and the pulsating instantaneous flow rate;

[0020] The ball valve pressure loss calculation module is used to calculate the total pressure drop loss of the rotary ball valve under pulsating flow based on the pulsating pressure drop loss of all throttling elements.

[0021] In the rotary ball valve pulsating flow pressure drop loss prediction system provided by the second aspect disclosed in the present invention, the throttling element pressure loss calculation module is specifically used to: obtain the pipeline instantaneous friction resistance coefficient, pipeline inner diameter, pipeline length, fluid density and pulsating fluid velocity of the upstream and downstream straight pipe sections, and then calculate the pulsating pressure drop loss of the upstream and downstream straight pipe sections; obtain the pulsating instantaneous flow rate at the thick orifice plate and the pressure loss coefficient of the thick orifice plate, and then calculate the pulsating pressure drop loss of the thick orifice plate; the number of the thin orifice plates is 2, respectively are the first thin orifice plate and the second thin orifice plate; obtain the pulsating instantaneous flow at the first thin orifice plate and the pressure loss coefficient of the first thin orifice plate, and then calculate the pulsating pressure drop loss of the first thin orifice plate; obtain the pulsating instantaneous flow at the second thin orifice plate and the pressure loss coefficient of the second thin orifice plate, and then calculate the pulsating pressure drop loss of the second thin orifice plate; obtain the local resistance coefficient of the Z-type bend at the sharp angle bend, the pulsating instantaneous flow of the Z-type bend and the cross-sectional area of ​​the ball valve inlet, and then calculate the pulsating pressure drop loss of the Z-type bend.

[0022] In the rotary ball valve pressure drop loss prediction system under pulsating flow provided in the second aspect of the present invention, the ball valve pressure loss calculation module is specifically used to: sum the pulsating pressure drop losses of all throttling elements to obtain the total pressure drop loss of the rotary ball valve under pulsating flow.

[0023] According to the third aspect disclosed in the present invention, there is also provided a device for predicting the pressure drop loss of a rotary ball valve under pulsating flow, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the method for predicting the pressure drop loss of a rotary ball valve under pulsating flow proposed in the first aspect disclosed in the present invention.

[0024] In one or more aspects disclosed in the present invention, an equivalent model of a rotary O-type ball valve flow passage is established, and the equivalent model includes four throttling elements: a thick orifice plate, a thin orifice plate, a Z-shaped elbow, and a straight pipe section upstream and downstream from the pressure measuring point of the ball valve; the pulsating fluid velocity and pulsating instantaneous flow in the throttling element are obtained, and the pulsating pressure drop loss corresponding to each throttling element is calculated based on the pulsating fluid velocity and pulsating instantaneous flow; the total pressure drop loss of the rotary ball valve under pulsating flow is calculated based on the pulsating pressure drop loss of all throttling elements. In this case, an equivalent model of the rotary O-type ball valve flow passage is proposed, and the total pulsating pressure drop loss of the ball valve can be quickly calculated based on the specific geometric dimensions of the ball valve and the working conditions of the pipeline flow, which greatly improves the calculation efficiency, and thus can improve the calculation efficiency when predicting the pressure drop loss.

[0025] Additional aspects and advantages of the present disclosure will be set forth in part in the following description and, in part, will be obvious from the following description, or may be learned by practice of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0027] FIG1 is a schematic flow chart showing a method for predicting pressure drop loss of a rotary ball valve under pulsating flow, provided by an embodiment of the present invention;

[0028] FIG2 shows a top view of the flow passage of a rotary O-type reduced-diameter ball valve provided by an embodiment of the present invention;

[0029] FIG3 shows an equivalent model of a flow passage of a rotary O-type reduced-diameter ball valve provided by an embodiment of the present invention;

[0030] FIG4 shows an equivalent model and three throttling elements provided by an embodiment of the present invention;

[0031] FIG5 is a schematic diagram showing the internal flow pattern of a thick orifice plate according to an embodiment of the present invention;

[0032] FIG6 is a schematic diagram showing the internal flow pattern of a thin orifice plate according to an embodiment of the present invention;

[0033] FIG7 is a schematic diagram showing the flow area of ​​the valve hole of a ball valve provided by an embodiment of the present invention;

[0034] FIG8 shows a graph showing the change of the flow area with the valve opening during the opening process of the ball valve provided by the embodiment of the present invention;

[0035] FIG9 shows a flow direction diagram during the valve core rotation process according to an embodiment of the present invention;

[0036] FIG10 shows a schematic diagram of a bent pipe structure provided by an embodiment of the present invention;

[0037] FIG11 shows a block diagram of a system for predicting pressure drop loss in a rotary ball valve under pulsating flow according to an embodiment of the present invention;

[0038] FIG12 is a block diagram of a device for predicting pressure drop loss of a rotary ball valve under pulsating flow, which is used to implement the method for predicting pressure drop loss of a rotary ball valve under pulsating flow according to an embodiment of the present invention. DETAILED DESCRIPTION

[0039] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all possible implementations consistent with the disclosed embodiments. Rather, they are merely examples of apparatuses and methods consistent with certain aspects of the disclosed embodiments, as detailed in the appended claims.

[0040] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example disclosed in the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0041] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description disclosed in the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined. It should also be understood that the term "and / or" used in the disclosure of the present invention refers to and includes any or all possible combinations of one or more associated listed items.

[0042] The following describes in detail embodiments of the present invention, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present invention, and should not be construed as limiting the present invention.

[0043] The present invention discloses a method, system and device for predicting pressure drop loss of a rotary ball valve under pulsating flow, the main purpose of which is to improve the calculation efficiency when predicting pressure drop loss.

[0044] In the first embodiment, FIG1 shows a flow chart of a method for predicting pressure drop loss of a rotary ball valve under pulsating flow provided by an embodiment of the present invention. As shown in FIG1 , the method for predicting pressure drop loss of a rotary ball valve under pulsating flow includes:

[0045] Step S11 , establishing an equivalent model of the flow channel of the rotary O-type ball valve, the equivalent model including four throttling elements: a thick orifice plate, a thin orifice plate, a Z-bend pipe, and straight pipe sections upstream and downstream of the ball valve pressure measuring point.

[0046] In this embodiment, considering that the rotary O-type ball valve can be equivalent to multiple throttling elements to calculate the pulsating pressure drop loss (i.e., the total pressure drop loss) of the ball valve, an equivalent model is established for the flow path of the rotary O-type ball valve in step S11. The equivalent model includes four throttling elements: a thick orifice plate, a thin orifice plate, a Z-bend pipe, and straight pipe sections upstream and downstream of the pressure measurement point of the ball valve.

[0047] In step S11, the upstream and downstream straight pipe sections from the ball valve pressure measurement point include the upstream straight pipe section and the downstream straight pipe section. The number of thick orifice plates is 1. The number of thin orifice plates is 2, and each thin orifice plate is a crescent-shaped thin orifice plate. The opening of each of the two crescent-shaped thin orifice plates is variable. The number of Z-bend pipes is 1.

[0048] In step S11, the thick orifice plate and the thin orifice plate are divided based on the thickness ratio (t / d) of the orifice plate. Here, t is the orifice thickness and d is the orifice diameter. If t / d < 0.5, it is a thin orifice plate; if t / d > 0.5, it is a thick orifice plate. Understandably, the thickness ratio directly affects the flow state inside the orifice plate, and the flow state of the orifice plate in turn directly affects the flow resistance and pressure drop.

[0049] In step S11, the rotary O-ball valve can be, but is not limited to, a rotary O-reducing ball valve.

[0050] Taking the rotary O-reducing ball valve as an example, the reasons for modeling will be specifically described below.

[0051] Figure 2 shows the top view of the flow channel of the rotary O-reducing ball valve provided by the disclosed embodiment of the present invention. Figure 3 shows the equivalent model of the flow channel of the rotary O-reducing ball valve provided by the disclosed embodiment of the present invention. Figure 4 shows the equivalent model and three throttling elements provided by the disclosed embodiment of the present invention.

[0052] In step S11, when the valve core of the rotary O-reducing ball valve rotates a certain angle, the top view of the ball valve flow channel is as shown in Figure 2. The rotary O-reducing ball valve includes a ball valve body, a ball valve upstream pipeline, and a ball valve downstream pipeline. Here, R is the radius of the ball valve body, r is the radius of the valve hole, D p is the internal diameter of the pipeline of the ball valve upstream pipeline, and the internal diameter of the pipeline of the ball valve downstream pipeline is equal to the internal diameter of the ball valve upstream pipeline. P i is the inlet pressure of the ball valve, U i is the inlet flow velocity of the ball valve, P o is the outlet pressure of the ball valve, U o is the outlet flow velocity of the ball valve. d1 is the flow channel diameter of the inlet and outlet sections of the ball valve, d is the flow channel diameter of the ball valve core. For a reducing ball valve, d < d1. L1 and L3 are respectively the lengths of the ball valve upstream pipeline and the ball valve downstream pipeline, L2 is the length of the ball valve, and L4 is the length of the valve core. The upstream and downstream pipelines are thread-connected to the inlet and outlet sections of the ball valve, and their inner diameters are equal.

[0053] According to the flow channel structure of the rotary O-reducing ball valve shown in Figure 2, considering the key geometric structure factors affecting the flow resistance and pressure drop of the ball valve, the structure of the ball valve flow channel can be equivalent to Figure 3. As can be seen from Figure 3, the resistance loss and pressure drop of the valve mainly occur at several pipe sections, including the frictional resistance losses of the upstream and downstream pipelines, the sudden contraction and expansion inside the valve, and the sudden change in the fluid direction during the rotation of the valve, etc. Therefore, the flow channel of the rotary O-reducing ball valve can be equivalent to four throttling elements to calculate the flow resistance and pressure drop losses.

[0054] As shown in Figure 4, the upstream and downstream pipelines of the ball valve are equivalent to the upstream and downstream straight pipe sections from the ball valve pressure measurement point. The ball valve body is equivalent to three throttling elements: a thick orifice plate (Figure 4 (a)), two crescent-shaped thin orifice plates with variable openings (Figure 4 (b)), and a Z-shaped bend (Figure 4 (c)). L represents the bend length, and θ represents the rotation angle of the ball valve.

[0055] In this embodiment, the total pressure drop loss of the rotary O-type ball valve under pulsating flow conditions can be obtained by calculating the pressure drop loss (i.e., pulsating pressure drop loss) of the four equivalent throttling elements shown in Figure 4 under pulsating flow conditions through subsequent steps.

[0056] Step S12: obtaining the pulsating fluid velocity and the pulsating instantaneous flow rate in the throttling element, and calculating the pulsating pressure drop loss corresponding to each throttling element based on the pulsating fluid velocity and the pulsating instantaneous flow rate.

[0057] In step S12, the method for calculating the pulsating pressure drop loss of the upstream and downstream straight pipe sections includes: obtaining the pipeline instantaneous friction resistance coefficient, pipeline inner diameter, pipeline length, fluid density and pulsating fluid velocity of the upstream and downstream straight pipe sections, and then calculating the pulsating pressure drop loss of the upstream and downstream straight pipe sections.

[0058] The pulsating pressure drop loss ΔP1 of the upstream and downstream straight pipe sections from the ball valve pressure measuring point satisfies formula (1):

[0059] In formula (1), f λ (t) is the instantaneous friction resistance coefficient of the pipeline; D p The inner diameter of the pipe connected to the ball valve (i.e. the inner diameter of the pipe upstream of the ball valve or the pipe downstream of the ball valve), unit: m; L p is the pipe length of the upstream and downstream straight pipe sections (i.e., the sum of the lengths of the upstream straight pipe section and the downstream straight pipe section), in meters; ρ is the fluid density, in kg / m 3 ;u f (t) is the pulsating fluid velocity, in m / s.

[0060] In step S12, the method for calculating the pulsating pressure drop loss of the thick orifice plate includes: obtaining the pulsating instantaneous flow at the thick orifice plate and the pressure loss coefficient of the thick orifice plate, and then calculating the pulsating pressure drop loss of the thick orifice plate.

[0061] Specifically, Figure 5 shows a schematic diagram of the internal flow pattern of the thick orifice plate provided by the disclosed embodiment of the present invention. It can be seen from the equivalent thick orifice plate shown in Figure 4 (a) that due to the structural characteristics of the reduced-diameter ball valve itself, the fluid in the tube will suddenly contract and expand when flowing into and out of the valve core channel, and the energy loss generated thereby can be equivalent to a thick orifice plate. The schematic diagram of the internal flow pattern of the thick orifice plate is shown in Figure 5. In Figure 5, 1 and 2 represent the upstream and downstream positions of the thick orifice plate; 0 represents the inlet position of the thick orifice hole; and c represents the position where the fluid contraction area in the thick orifice plate is the smallest. The areas at positions 1, 2, 0 and c are represented as A1, A2, A0 and A2, respectively. c The area A at point c c is the minimum contraction area. The fluid dynamics in the orifice plate is controlled by the contraction flow and the subsequent expansion flow. At the minimum contraction area, the jet area is the smallest, the flow velocity is the largest, and the pressure is the smallest.

[0062] Based on the dimensions of the rotary O-type reducing ball valve shown in Figure 2, A0=πd 2 / 4. Area ratio of thick orifice plate σ thick Satisfying formula (2):

[0063] In this embodiment, the Chisholm formula is used to calculate the area shrinkage ratio σ of the thick orifice plate. c-thick , the area shrinkage ratio σ of the thick hole plate c-thick Satisfying formula (3):

[0064] The pulsating pressure drop loss ΔP2 of a thick orifice plate satisfies formula (4):

[0065] In formula (4), Q(t) represents the pulsating instantaneous flow rate, unit is m 3 / h; K1 represents the first pressure loss coefficient of the thick orifice plate, and K2 represents the second pressure loss coefficient of the thick orifice plate. Both the first and second pressure loss coefficients do not change with the opening of the ball valve.

[0066] Among them, the first pressure loss coefficient and the second pressure loss coefficient of the thick orifice plate satisfy formula (5):

[0067] In formula (5), A0 represents the cross-sectional area of ​​the ball valve flow channel (i.e., the area at the inlet position 0 of the thick orifice plate hole), unit: m 2 ; C δ1 Indicates the irrecoverable pressure drop coefficient of the thick orifice plate, L jet1 Indicates the effective contraction length of the thick orifice plate.

[0068] Among them, the irrecoverable pressure drop coefficient C of the thick orifice plate is δ1 Satisfying formula (6):

[0069] In formula (6), C d1 is the flow coefficient of the thick orifice plate, the flow coefficient C of the thick orifice plate d1 Satisfying formula (7):

[0070] In formula (7), ξ thick It represents the flow resistance coefficient of thick orifice plate under steady flow.

[0071] In formula (5), the effective contraction length L of the thick hole plate is jet1 Satisfying formula (8):

[0072] In formula (8), l o1 represents the length of the thick orifice plate hole, is a function of the diameter reduction ratio (d / d1) of the thick orifice plate, which satisfies formula (9):

[0073] In this embodiment, by substituting equations (5) to (9) into equation (4), the pulsating pressure drop loss ΔP2 of the thick orifice plate under pulsating flow conditions can be obtained.

[0074] In step S12, the number of thin orifice plates is 2, namely the first thin orifice plate and the second thin orifice plate; the calculation method of the pulsating pressure drop loss of the first thin orifice plate and the second thin orifice plate includes: obtaining the pulsating instantaneous flow at the first thin orifice plate and the pressure loss coefficient of the first thin orifice plate, and then calculating the pulsating pressure drop loss of the first thin orifice plate; obtaining the pulsating instantaneous flow at the second thin orifice plate and the pressure loss coefficient of the second thin orifice plate, and then calculating the pulsating pressure drop loss of the second thin orifice plate.

[0075] Specifically, Figure 6 illustrates a schematic diagram of the flow pattern within a thin orifice plate according to an embodiment of the present invention. Figure 7 illustrates a schematic diagram of the flow area of ​​a ball valve orifice according to an embodiment of the present invention. Figure 8 illustrates a graph showing the change in flow area as the ball valve orifice opens, according to an embodiment of the present invention.

[0076] It can be seen from the equivalent thin orifice plate shown in Figure 4 (b) that during the rotation of the ball valve core, the ball valve is partially opened, and the valve port can be equivalent to two thin orifice plates with variable openings. The schematic diagram of the flow pattern inside the thin orifice plate is shown in Figure 6. In Figure 6, 1' and 2' represent the upstream and downstream positions of the thin orifice plate; 0' represents the inlet position of the thin orifice plate hole; and c' represents the position where the fluid contraction area in the thin orifice plate is the smallest. The areas at positions 1', 2', 0' and c' are represented as A'1, A'2, A'0 and A', respectively. c The area A' at position c' c Indicates the minimum area of ​​the thin orifice plate contraction flow. According to Figure 6, the area A'1 at position 1' represents the flow area of ​​the flow channel when the ball valve is fully open, A'1 = A'2 = πd2 / 4=A0; the area A′0 at position 0′ represents the flow area S of the flow channel when the ball valve is partially open Flow , that is, A′0=S Flow .

[0077] Figure 7 shows a cross-sectional view of a ball valve during rotation. (a) of Figure 7 shows a longitudinal cross-sectional view of the ball valve and its coordinate system, and (b) of Figure 7 shows the projection of the valve orifice area on the xy plane. The ball valve body radius is R, and the valve orifice radius is r. A Cartesian coordinate system (xyz coordinate system) is used here, with the origin O fixed at the center of the sphere. The x-axis is defined as parallel to the pipeline flow direction, the y-axis is perpendicular to the pipeline flow direction, and the z-axis coincides with the ball valve stem. The valve handle is connected to the valve stem, and the valve core can be rotated to adjust and control the fluid, assuming that the fluid flows from left to right. As shown in Figure 7, when the ball valve is fully open, the projection of the ball valve hole on the xy plane is a circle with a radius of r, and the center of the circle is located at O1. At this time, the flow area is equal to the valve hole area; when the rotation angle of the ball valve is θ, the projection of the ball valve hole on the xy plane is an ellipse with a major axis of r and a minor axis of rcosθ, and the center of the circle is located at O2. At this time, the flow area is the intersection of the circle O1 and the ellipse O2. M and P are the intersection points of the circle O1 and the ellipse O2, F is the intersection point of the circle O1 and the straight line O1 O2, E is the intersection point of the ellipse O2 and the straight line O1 O2, and N is the intersection point of the line segment EF and the line segment MP, as shown in the blue area in Figure 7. Flow area S Flow The calculation formula is formula (10):

[0078] As the ball valve opens, the flow area changes with opening, as viewed from the flow direction. The blue area in Figure 8 shows this change, with O' being the center. As the ball valve opening increases, the flow area increases. The non-blue area represents the valve orifice, which is crescent-shaped. Its area gradually decreases with increasing opening, reaching zero when the valve is fully open.

[0079] In this embodiment, the area ratio of the thin orifice plate is thin Satisfying formula (11):

[0080] In this embodiment, the Chisholm formula is used to calculate the area shrinkage ratio σ of the thin orifice plate. c-thin , the area shrinkage ratio of the thin plate σ c-thin Satisfying formula (12):

[0081] Since there are two thin orifice plates, the pulsating pressure drop loss ΔP of a crescent-shaped thin orifice plate with variable opening is calculated first. 31 . Pulsating pressure drop loss ΔP 31 Satisfying formula (13):

[0082] In formula (13), Q(t) represents the pulsating instantaneous flow rate, unit is m 3 / h, K'1 represents the first pressure loss coefficient of the thin orifice plate, and K'2 represents the second pressure loss coefficient of the thin orifice plate. Both the first and second pressure loss coefficients change with the opening of the ball valve.

[0083] Among them, the first pressure loss coefficient and the second pressure loss coefficient of the thin orifice plate satisfy formula (14):

[0084] In formula (14), S Flow Indicates the flow area of ​​the flow channel when the ball valve is partially open, C δ2 Indicates the irrecoverable pressure drop coefficient of the thin orifice plate, L jet2 Represents the effective contraction length of the thin orifice plate.

[0085] Among them, the irrecoverable pressure drop coefficient C of the thin orifice plate is δ2 Satisfying formula (15):

[0086] In formula (15), C d2 is the flow coefficient of the thin orifice plate, the flow coefficient C of the thin orifice plate d2 Satisfying formula (16):

[0087] In formula (16), ξ thin It represents the flow resistance coefficient of a thin orifice plate under steady-state flow.

[0088] In formula (14), the effective contraction length L of the thin plate is jet2 Satisfying formula (17):

[0089] In formula (17), l o2 Represents the length of the thin orifice plate hole, d o2 represents the effective hydraulic diameter of the thin orifice plate, is the diameter reduction ratio d of the thin orifice plate o2 / d function.

[0090] Among them, the effective hydraulic diameter d of the thin orifice plate o2 Satisfying formula (18):

[0091] Reduction ratio d of thin orifice plate o2 Function of / d Satisfying formula (19):

[0092] In this embodiment, by substituting equations (14) to (19) into equation (13), the pulsating pressure drop loss ΔP of a crescent-shaped thin orifice plate with variable opening under pulsating flow conditions can be obtained: 31Since the pulsating pressure drop loss at the valve port when the ball valve is partially open can be equivalent to the pulsating pressure drop loss caused by two thin orifice plates with variable openings, the pulsating pressure drop loss ΔP3 at the valve port when the ball valve is partially open (i.e., the pulsating pressure drop loss of the two crescent-shaped thin orifice plates with variable openings) satisfies formula (20): ΔP3=2ΔP 31 (20)

[0093] In step S12, the method for calculating the pulsating pressure drop loss of the Z-bend includes: obtaining the local resistance coefficient of the Z-bend at the sharp bend, the pulsating instantaneous flow of the Z-bend and the cross-sectional area of ​​the ball valve inlet, and then calculating the pulsating pressure drop loss of the Z-bend.

[0094] Specifically, Figure 9 illustrates a diagram of the fluid flow during valve core rotation according to an embodiment of the present invention. Figure 10 illustrates a schematic diagram of a pipe bend structure according to an embodiment of the present invention. Figure 10 (a) illustrates a Z-shaped pipe bend, and Figure 10 (b) illustrates a sharp-angle pipe bend. Here, θ represents the rotation angle of the ball valve, and d represents the pipe bend diameter (i.e., the ball valve core flow path diameter).

[0095] Considering that when the fluid in the pipe flows into the ball valve under pressure drive, the flow resistance loss includes not only the local flow resistance caused by the change in valve opening, but also the local flow resistance caused by the sudden change in flow direction due to the rotation of the valve core. As shown in Figure 9, when the fluid flows into and out of the ball valve core in the direction of the arrow, the fluid direction suddenly changes, causing a non-negligible pressure loss. The pressure loss caused by the sudden change in fluid direction in Figure 9 can be equivalent to the pressure loss of a Z-shaped bend, and the equivalent Z-shaped bend is shown in (c) of Figure 4. The structural schematic diagram of the equivalent Z-shaped bend shown in (c) of Figure 4 is shown in (a) of Figure 10. Since the Z-shaped bend can be regarded as a combination of two sharp-angled bends (i.e. (b) of Figure 10), two sharp-angled bends are used instead of the Z-shaped bend to calculate the flow resistance loss caused by the change in fluid direction during the rotation of the ball valve.

[0096] In this embodiment, the pulsating pressure drop loss ΔP4 of the Z-bend pipe satisfies formula (21):

[0097] In formula (21), ξ elbow represents the local resistance coefficient of the sharp-angled bend (i.e., the sharp bend) shown in Figure 9 (b), Q(t) represents the pulsating instantaneous flow rate, in units of m 3 / h, A1 represents the cross-sectional area of ​​the ball valve inlet (i.e. the area at position 1 in Figure 5), unit: m 2 .

[0098] Among them, the local resistance coefficient of the sharp-angle elbow ξ elbow Satisfying formula (22): ξ elbow =α·β·ξM (twenty two)

[0099] In formula (22), ξ M Based on formula (23), formula (23) satisfies:

[0100] In formula (23), θ represents the rotation angle of the ball valve. The coefficients α and β satisfy formulas (24) and (25), respectively:

[0101] In equations (24) and (25), r1 represents the radius of curvature of the bend axis, which can be approximately taken as L4 sinθ, and d represents the diameter of the bend, which is approximately equal to As shown in (b) of Figure 7, the elbow diameter d satisfies formula (26):

[0102] In this embodiment, by substituting equations (22) to (26) into equation (21), the pulsating pressure drop loss ΔP4 of a Z-bend pipe can be obtained.

[0103] Step S13: calculating the total pressure drop loss of the rotary ball valve under pulsating flow based on the pulsating pressure drop losses of all throttling elements.

[0104] In step S13, the total pressure drop loss of the rotary ball valve under pulsating flow is calculated based on the pulsating pressure drop losses of all throttling elements, including: summing the pulsating pressure drop losses of all throttling elements to obtain the total pressure drop loss of the rotary ball valve under pulsating flow. That is, the total pressure drop loss ΔP satisfies formula (27): ΔP=ΔP1+ΔP2+ΔP3+ΔP4 (27)

[0105] In this embodiment, the total pressure drop loss ΔP of the rotary O-type ball valve under pulsating flow conditions can be calculated by substituting equations (1), (4), (20) and (21) into equation (27) and summing them.

[0106] In the method for predicting the pressure drop loss of a rotary ball valve under pulsating flow in the disclosed embodiment of the present invention, an equivalent model of the flow channel of a rotary O-type ball valve is established, and the equivalent model includes four throttling elements: a thick orifice plate, a thin orifice plate, a Z-shaped elbow, and a straight pipe section upstream and downstream from the pressure measuring point of the ball valve; the pulsating fluid velocity and the pulsating instantaneous flow in the throttling element are obtained, and the pulsating pressure drop loss corresponding to each throttling element is calculated based on the pulsating fluid velocity and the pulsating instantaneous flow; the total pressure drop loss of the rotary ball valve under pulsating flow is calculated based on the pulsating pressure drop loss of all throttling elements. In this case, an equivalent model of the flow channel of a rotary O-type ball valve is proposed, and the total pulsating pressure drop loss of the ball valve can be quickly calculated based on the specific geometric dimensions of the ball valve and the working conditions of the pipeline flow, which greatly improves the calculation efficiency, and thus can improve the calculation efficiency when predicting the pressure drop loss. In addition, the method disclosed in the present invention is a theoretical prediction and calculation method proposed based on the inherent mechanism of the flow resistance and pressure drop of the ball valve. It overcomes the shortcomings of the experimental method, which is time-consuming, costly, and has a single working condition and poor flexibility, as well as the serious defects of the numerical simulation method, which is computationally intensive, time-consuming, and unable to converge nonlinearly. It only takes a few seconds to quickly calculate the pulsating pressure drop loss of the rotary O-type ball valve, greatly improving the calculation efficiency, and can be used to guide the design and use of ball valves in actual engineering.

[0107] The prediction method disclosed in the embodiment of the present invention is a method for calculating the pulsating pressure drop loss of a rotary O-type ball valve, which can efficiently predict the pressure drop loss of a pulsating fluid passing through a rotary O-type ball valve. The method has multiple beneficial effects, specifically:

[0108] 1) Based on the inherent mechanism of flow resistance and pressure drop in hydraulic piping systems, an equivalent model is proposed for rotary ball valves. This equivalent model is an equivalent model for studying the pulsating pressure drop loss under different openings of the ball valve. The equivalent model regards the rotary ball valve as a combination of four interconnected throttling elements, including: upstream and downstream straight pipe sections from the pressure measuring point of the ball valve, a thick orifice plate, two eccentric crescent-shaped thin orifice plates with variable openings, and a Z-shaped bend. By analyzing the pulsating pressure drops of these four equivalent throttling elements, the total pulsating pressure drop of the entire ball valve system can be obtained (i.e., the total pressure drop loss of the ball valve under pulsating flow conditions). This equivalent model provides a research method for the theoretical calculation of ball valve flow resistance and pressure drop, and is applicable to both steady-state flow and unsteady pulsating flow;

[0109] 2) The method disclosed in the present invention eliminates the reliance on numerical simulation and experimental data for pressure drop calculations in the past. Instead, the total pulsating pressure drop of the ball valve can be quickly calculated based on the specific geometric dimensions of the ball valve and the working conditions of the pipeline flow, greatly improving calculation efficiency.

[0110] 3) The method disclosed in the present invention fills the gap in the theoretical calculation of ball valve pressure drop in current engineering, and proposes a theoretical prediction model that can be applied in engineering to calculate the pulsating pressure drop of ball valves at different openings.

[0111] The following are system embodiments disclosed in the present invention, which can be used to implement the method embodiments disclosed in the present invention. For details not disclosed in the system embodiments disclosed in the present invention, please refer to the method embodiments disclosed in the present invention.

[0112] Please refer to Figure 11, which shows a block diagram of a rotary ball valve pressure drop loss prediction system under pulsating flow, provided by an embodiment of the present invention. The rotary ball valve pressure drop loss prediction system under pulsating flow can be implemented as all or part of a system through software, hardware, or a combination of both. The rotary ball valve pressure drop loss prediction system 10 under pulsating flow includes a modeling module 11, a throttling element pressure loss calculation module 12, and a ball valve pressure loss calculation module 13, wherein:

[0113] Modeling module 11, used to establish an equivalent model of the flow channel of the rotary O-type ball valve, the equivalent model including four throttling elements: a thick orifice plate, a thin orifice plate, a Z-bend pipe, and a straight pipe section upstream and downstream of the pressure measuring point of the ball valve;

[0114] The throttling element pressure loss calculation module 12 is used to obtain the pulsating fluid velocity and pulsating instantaneous flow rate in the throttling element, and calculate the pulsating pressure drop loss corresponding to each throttling element based on the pulsating fluid velocity and pulsating instantaneous flow rate;

[0115] The ball valve pressure loss calculation module 13 is used to calculate the total pressure drop loss of the rotary ball valve under pulsating flow based on the pulsating pressure drop losses of all throttling elements.

[0116] Optionally, the throttling element pressure loss calculation module 12 is specifically used to obtain the pipeline instantaneous friction resistance coefficient, pipeline inner diameter, pipeline length, fluid density and pulsating fluid velocity of the upstream and downstream straight pipe sections, and then calculate the pulsating pressure drop loss of the upstream and downstream straight pipe sections.

[0117] Optionally, the throttling element pressure loss calculation module 12 is specifically used to obtain the pulsating instantaneous flow at the thick orifice plate and the pressure loss coefficient of the thick orifice plate, and then calculate the pulsating pressure drop loss of the thick orifice plate.

[0118] Optionally, there are two orifice plates, namely a first orifice plate and a second orifice plate. The throttling element pressure loss calculation module 12 is specifically configured to: obtain the pulsating instantaneous flow rate at the first orifice plate and the pressure loss coefficient of the first orifice plate, thereby calculating the pulsating pressure drop loss of the first orifice plate; obtain the pulsating instantaneous flow rate at the second orifice plate and the pressure loss coefficient of the second orifice plate, thereby calculating the pulsating pressure drop loss of the second orifice plate.

[0119] Optionally, the throttling element pressure loss calculation module 12 is specifically used to obtain the local resistance coefficient of the Z-bend at the sharp bend, the pulsating instantaneous flow of the Z-bend and the cross-sectional area of ​​the ball valve inlet, and then calculate the pulsating pressure drop loss of the Z-bend.

[0120] Optionally, the ball valve pressure loss calculation module 13 is specifically configured to sum the pulsating pressure drop losses of all throttling elements to obtain the total pressure drop loss of the rotary ball valve under pulsating flow.

[0121] It should be noted that the rotary ball valve pulsating flow pressure drop loss prediction system provided in the above embodiment only uses the division of the above functional modules as an example when executing the rotary ball valve pulsating flow pressure drop loss prediction method. In actual applications, the above functional distribution can be completed by different functional modules as needed, that is, the internal structure of the rotary ball valve pulsating flow pressure drop loss prediction device is divided into different functional modules to complete all or part of the functions described above. In addition, the rotary ball valve pulsating flow pressure drop loss prediction system provided in the above embodiment and the rotary ball valve pulsating flow pressure drop loss prediction method embodiment belong to the same concept. The implementation process is detailed in the method embodiment and will not be repeated here.

[0122] The serial numbers of the embodiments disclosed in the present invention are for description only and do not represent the advantages or disadvantages of the embodiments.

[0123] In the rotary ball valve pressure drop loss prediction system under pulsating flow of the disclosed embodiment of the present invention, the modeling module is used to establish an equivalent model of the rotary O-type ball valve flow channel, and the equivalent model includes four throttling elements: thick orifice plate, thin orifice plate, Z-type elbow and upstream and downstream straight pipe sections from the ball valve pressure measuring point; the throttling element pressure loss calculation module is used to obtain the pulsating fluid velocity and pulsating instantaneous flow in the throttling element, and calculate the pulsating pressure drop loss corresponding to each throttling element based on the pulsating fluid velocity and pulsating instantaneous flow; the ball valve pressure loss calculation module is used to calculate the total pressure drop loss of the rotary ball valve under pulsating flow based on the pulsating pressure drop loss of all throttling elements. In this case, an equivalent model of the rotary O-type ball valve flow channel is proposed, and the total pulsating pressure drop loss of the ball valve can be quickly calculated based on the specific geometric dimensions of the ball valve and the working conditions of the pipeline flow, which greatly improves the calculation efficiency, and thus can improve the calculation efficiency when predicting pressure drop loss. In addition, the system disclosed in the present invention is a theoretical prediction and calculation system proposed based on the inherent mechanism of the flow resistance and pressure drop of the ball valve. It overcomes the shortcomings of the experimental method, which is time-consuming, costly, and has a single working condition and poor flexibility, as well as the serious defects of the numerical simulation method, which is computationally intensive, time-consuming, and unable to converge nonlinearly. It only takes a few seconds to quickly calculate the pulsating pressure drop loss of the rotary O-type ball valve, greatly improving the calculation efficiency, and can be used to guide the design and use of ball valves in actual engineering projects.

[0124] According to an embodiment disclosed in the present invention, the present invention also provides a device for predicting pressure drop loss under pulsating flow of a rotary ball valve, a readable storage medium, and a computer program product.

[0125] Figure 12 is a block diagram of a rotary ball valve pulsating flow pressure drop loss prediction device for implementing a rotary ball valve pulsating flow pressure drop loss prediction method according to an embodiment of the present invention. The rotary ball valve pulsating flow pressure drop loss prediction device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The rotary ball valve pulsating flow pressure drop loss prediction device can also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable electronic devices, and other similar computing devices. The components, connections and relationships of the components, and functions of the components shown in the present invention are merely examples and are not intended to limit the implementation of the present invention described and / or required in the present invention.

[0126] As shown in FIG12 , the device 20 for predicting pressure drop loss under pulsating flow conditions for a rotary ball valve includes a computing unit 21, which can perform various appropriate actions and processes based on a computer program stored in a read-only memory (ROM) 22 or a computer program loaded from a storage unit 28 into a random access memory (RAM) 23. RAM 23 may also store various programs and data required for the operation of the device 20 for predicting pressure drop loss under pulsating flow conditions for a rotary ball valve. The computing unit 21, ROM 22, and RAM 23 are interconnected via a bus 24. An input / output (I / O) interface 25 is also connected to the bus 24.

[0127] Multiple components in the device 20 for predicting pressure drop loss under pulsating flow of a rotary ball valve are connected to an I / O interface 25, including: an input unit 26, such as a keyboard, a mouse, etc.; an output unit 27, such as various types of displays, speakers, etc.; a storage unit 28, such as a magnetic disk, an optical disk, etc., which is communicatively connected to the computing unit 21; and a communication unit 29, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 29 allows the device 20 for predicting pressure drop loss under pulsating flow of a rotary ball valve to exchange information / data with other devices for predicting pressure drop loss under pulsating flow of a rotary ball valve via a computer network such as the Internet and / or various telecommunication networks.

[0128] The computing unit 21 can be a variety of general and / or special processing components with processing and computing capabilities. Some examples of the computing unit 21 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various dedicated artificial intelligence (AI) computing chips, various computing units that run machine learning model algorithms, digital signal processors (DSPs), and any appropriate processors, controllers, microcontrollers, etc. The computing unit 21 performs the various methods and processes described above, such as executing the method for predicting the pressure drop loss under pulsating flow of a rotary ball valve. For example, in some embodiments, the method for predicting the pressure drop loss under pulsating flow of a rotary ball valve can be implemented as a computer software program, which is tangibly contained in a machine-readable medium, such as a storage unit 28. In some embodiments, part or all of the computer program can be loaded and / or installed on the rotary ball valve pulsating flow pressure drop loss prediction device 20 via the ROM 22 and / or the communication unit 29. When the computer program is loaded into the RAM 23 and executed by the computing unit 21, one or more steps of the method for predicting the pressure drop loss under pulsating flow of a rotary ball valve described above can be performed. Alternatively, in other embodiments, the computing unit 21 may be configured to execute the method for predicting the pressure drop loss of a rotary ball valve under pulsating flow in any other appropriate manner (for example, by means of firmware).

[0129] Various embodiments of the systems and techniques described above in the present disclosure may be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), system-on-chip systems (SOCs), programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include being implemented in one or more computer programs that are executable and / or interpreted on a programmable system comprising at least one programmable processor, which may be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0130] The program code for implementing the method disclosed in the present invention can be written in any combination of one or more programming languages. These program codes can be provided to a processor or controller of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that when the program code is executed by the processor or controller, the functions / operations specified in the flow chart and / or block diagram are implemented. The program code can be executed entirely on the machine, partially on the machine, as a stand-alone software package, partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0131] In the present disclosure, a machine-readable medium may be a tangible medium that may contain or store a program for use by an instruction execution system, device, or rotary ball valve pulsating flow pressure drop loss prediction device or in combination with an instruction execution system, device, or rotary ball valve pulsating flow pressure drop loss prediction device. The machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. The machine-readable medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or electronic device, or any suitable combination of the foregoing. More specific examples of machine-readable storage media may include electrical connections based on one or more wires, portable computer disks, hard disks, random access memories (RAM), read-only memories (ROM), erasable programmable read-only memories (EPROM or flash memory), optical fibers, portable compact disk read-only memories (CD-ROMs), optical storage electronic devices, magnetic storage electronic devices, or any suitable combination of the foregoing.

[0132] To provide interaction with a user, the systems and techniques described herein can be implemented on a computer having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user can provide input to the computer. Other types of devices can also be used to provide interaction with the user; for example, the feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including acoustic input, voice input, or tactile input).

[0133] The systems and techniques described herein can be implemented in a computing system that includes back-end components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes front-end components (e.g., a user computer with a graphical user interface or a web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such back-end components, middleware components, or front-end components. The components of the system can be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), the Internet, and a blockchain network.

[0134] A computer system may include a client and a server. The client and server are generally remote from each other and typically interact via a communication network. This client-server relationship is established by computer programs running on the respective computers, establishing a client-server relationship. The server may be a cloud server, also known as a cloud computing server or cloud host, a host product within the cloud computing service ecosystem that addresses the management difficulties and limited scalability of traditional physical hosts and VPS services ("Virtual Private Servers" or simply "VPS"). The server may also be a server in a distributed system or a server integrated with blockchain.

[0135] It should be understood that the various forms of the processes shown above can be used to reorder, add, or delete steps. For example, the steps described in the present disclosure can be performed in parallel, sequentially, or in a different order, as long as the desired results of the technical solutions disclosed in the present disclosure can be achieved. The present disclosure is not limited here.

[0136] The above specific embodiments do not constitute a limitation on the scope of protection disclosed in this invention. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may be made based on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles disclosed in this invention shall be included within the scope of protection disclosed in this invention.

Claims

1. A method for predicting pressure drop loss of a rotary ball valve under pulsating flow, characterized in that: include: An equivalent model of the flow channel of a rotary O-type ball valve is established, wherein the equivalent model includes four throttling elements: a thick orifice plate, a thin orifice plate, a Z-bend pipe, and a straight pipe section upstream and downstream of a pressure measuring point of the ball valve. Acquiring the pulsating fluid velocity and the pulsating instantaneous flow rate in the throttling element, and calculating the pulsating pressure drop loss corresponding to each throttling element based on the pulsating fluid velocity and the pulsating instantaneous flow rate; The total pressure drop loss of the rotary ball valve under pulsating flow is calculated based on the pulsating pressure drop loss of all throttling elements.

2. The method for predicting pressure drop loss of a rotary ball valve under pulsating flow according to claim 1, characterized in that: The calculation method of the pulsating pressure drop loss of the upstream and downstream straight pipe sections includes: The pipeline instantaneous friction resistance coefficient, pipeline inner diameter, pipeline length, fluid density and pulsating fluid velocity of the upstream and downstream straight pipe sections are obtained, and then the pulsating pressure drop loss of the upstream and downstream straight pipe sections is calculated.

3. The method for predicting pressure drop loss of a rotary ball valve under pulsating flow according to claim 1, characterized in that: The calculation method of the pulsating pressure drop loss of the thick orifice plate includes: The pulsating instantaneous flow at the thick orifice plate and the pressure loss coefficient of the thick orifice plate are obtained, and then the pulsating pressure drop loss of the thick orifice plate is calculated.

4. The method for predicting pressure drop loss of a rotary ball valve under pulsating flow according to claim 1, characterized in that: The number of the thin orifice plates is 2, namely a first thin orifice plate and a second thin orifice plate; The method for calculating the pulsating pressure drop loss of the first thin orifice plate and the second thin orifice plate comprises: Obtaining the pulsating instantaneous flow at the first thin orifice plate and the pressure loss coefficient of the first thin orifice plate, and then calculating the pulsating pressure drop loss of the first thin orifice plate; The pulsating instantaneous flow at the second thin orifice plate and the pressure loss coefficient of the second thin orifice plate are obtained, and then the pulsating pressure drop loss of the second thin orifice plate is calculated.

5. The method for predicting pressure drop loss of a rotary ball valve under pulsating flow according to claim 1, characterized in that: The method for calculating the pulsating pressure drop loss of the Z-bend pipe comprises: The local resistance coefficient of the Z-bend at the sharp bend, the pulsating instantaneous flow of the Z-bend and the cross-sectional area of ​​the ball valve inlet are obtained, and then the pulsating pressure drop loss of the Z-bend is calculated.

6. The method for predicting pressure drop loss of a rotary ball valve under pulsating flow according to claim 1, characterized in that: The total pressure drop loss of the rotary ball valve under pulsating flow is calculated based on the pulsating pressure drop loss of all throttling elements, including: The pulsating pressure drop losses of all throttling elements are summed to obtain the total pressure drop loss of the rotary ball valve under pulsating flow.

7. A system for predicting pressure drop loss under pulsating flow of a rotary ball valve, characterized in that: include: A modeling module is used to establish an equivalent model of the flow channel of a rotary O-type ball valve, wherein the equivalent model includes four throttling elements: a thick orifice plate, a thin orifice plate, a Z-bend pipe, and a straight pipe section upstream and downstream of a pressure measuring point of the ball valve; A throttling element pressure loss calculation module, used to obtain the pulsating fluid velocity and the pulsating instantaneous flow rate in the throttling element, and calculate the pulsating pressure drop loss corresponding to each throttling element based on the pulsating fluid velocity and the pulsating instantaneous flow rate; The ball valve pressure loss calculation module is used to calculate the total pressure drop loss of the rotary ball valve under pulsating flow based on the pulsating pressure drop loss of all throttling elements.

8. The system for predicting pressure drop loss under pulsating flow of a rotary ball valve according to claim 7, characterized in that: The throttling element pressure loss calculation module is specifically used for: Obtaining the pipeline instantaneous friction resistance coefficient, pipeline inner diameter, pipeline length, fluid density and pulsating fluid velocity of the upstream and downstream straight pipe sections, and then calculating the pulsating pressure drop loss of the upstream and downstream straight pipe sections; Obtaining the pulsating instantaneous flow at the thick orifice plate and the pressure loss coefficient of the thick orifice plate, and then calculating the pulsating pressure drop loss of the thick orifice plate; The number of the thin orifice plates is 2, namely a first thin orifice plate and a second thin orifice plate; Obtaining the pulsating instantaneous flow at the first thin orifice plate and the pressure loss coefficient of the first thin orifice plate, and then calculating the pulsating pressure drop loss of the first thin orifice plate; Obtaining the pulsating instantaneous flow at the second thin orifice plate and the pressure loss coefficient of the second thin orifice plate, and then calculating the pulsating pressure drop loss of the second thin orifice plate; The local resistance coefficient of the Z-bend at the sharp bend, the pulsating instantaneous flow of the Z-bend and the cross-sectional area of ​​the ball valve inlet are obtained, and then the pulsating pressure drop loss of the Z-bend is calculated.

9. The system for predicting pressure drop loss under pulsating flow of a rotary ball valve according to claim 7, characterized in that: The ball valve pressure loss calculation module is specifically used for: The pulsating pressure drop losses of all throttling elements are summed to obtain the total pressure drop loss of the rotary ball valve under pulsating flow.

10. A device for predicting pressure drop loss under pulsating flow of a rotary ball valve, characterized in that: include: at least one processor; And a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the method for predicting the pressure drop loss of a rotary ball valve under pulsating flow according to any one of claims 1-6.

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