A method for measuring flow rate at a U-shaped throttling slot valve port

Abstract

The present invention provides a method for measuring flow rate of a U-shaped throttling groove valve port, comprising the following steps: S1), obtaining a throttling area A1 and a throttling area B1 of the U-shaped throttling groove valve port according to actual size parameters of the U-shaped throttling groove valve port; S2), obtaining a flow resistance R in each throttling surface; zi ; S3), according to the flow resistance R z1 and R z2 Get the average flow resistance as the average flow resistance R of the U-shaped throttling groove valve port za ; S4) The valve port flow formula is used to obtain the actual flow q through the U-shaped throttling slot valve port. The method of the present invention fully considers the difference between flow characteristics under different throttling areas, and the measurement result is more accurate.

Description

Technical Field

[0001] The invention relates to the field of valve technology, in particular to a method for measuring flow at a U-shaped throttling groove valve port. Background Art

[0002] The U-shaped throttle groove valve port is cut along the axis of the valve core using a cylindrical milling cutter and is widely used in various valves such as pressure reducing valves and reversing valves. The flow characteristics of the valve port largely determine the stability of the actuator. Reasonable parameter settings can effectively avoid pressure shock and vibration, so it is very necessary to establish the precise flow characteristic equation of the U-shaped throttle groove valve port.

[0003] The U-shaped throttling groove valve port has obvious secondary throttling characteristics. However, most of the existing calculation methods equate the two throttling areas of the U-shaped throttling groove valve port, without considering the difference in flow characteristics under different throttling areas, thus affecting the accuracy of the final calculation results. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention provides a method for measuring the flow rate of a U-shaped throttling groove valve port. The method can accurately measure the flow rates of different throttling valves by fully considering the differences between flow characteristics under different throttling areas.

[0005] The technical solution of the present invention is: a method for measuring flow rate of a U-shaped throttling groove valve port, comprising the following steps:

[0006] S1), according to the actual size parameters of the U-shaped throttling groove valve port, obtain the throttling area A of the U-shaped throttling groove valve port 1 With throttling area B 1 ;

[0007] S2) Obtain the flow resistance R in each throttling surface zi (i=1,2);

[0008] S3), according to the flow resistance R z1 and R z2 Get the average flow resistance as the average flow resistance R of the U-shaped throttling groove valve port za ;

[0009] S4) The valve port flow formula is used to obtain the actual flow q through the U-shaped throttling groove valve port.

[0010] As a preferred embodiment, in step S1), when the valve opening x is smaller than the top circle radius R of the U-shaped throttling groove, the throttling area A 1 With throttling area B 1 The calculation formula is:

[0011]

[0012] Where R is the radius of the top circle of the U-shaped throttling groove, x is the valve opening, r is the valve core radius, and H is the depth of the U-shaped throttling groove.

[0013] Preferably, in step S1), when the valve opening x is greater than or equal to the top circle radius R of the U-shaped throttling groove, the throttling area A 1 With throttling area B 1 The calculation formula is:

[0014]

[0015] Where R is the radius of the top circle of the U-shaped throttling groove, x is the valve opening, r is the valve core radius, and H is the depth of the U-shaped throttling groove.

[0016] As a preference, the flow resistance R in each throttling surface is zi The calculation method for (i=1,2) is:

[0017]

[0018]

[0019] In the formula, C d1 is the flow coefficient of the first throttling surface, C d2 is the flow coefficient of the second throttling surface, R z1 is the flow resistance in the first throttling surface, R z2 is the flow resistance in the second throttling surface, and ρ is the liquid density.

[0020] As a preferred embodiment, in step S3), the average flow resistance R of the U-shaped throttling groove valve port za The expression is:

[0021]

[0022] Preferably, in step S4), the actual flow rate q through the U-shaped throttling groove valve port is:

[0023]

[0024] Where Δp is the pressure difference across the U-shaped throttling groove valve port.

[0025] The beneficial effects of the present invention are as follows: the method of the present invention fully considers the differences between flow characteristics under different throttling areas, and the measurement result is more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a flow chart of the method for calculating flow rate of a U-shaped throttling groove valve port of the present invention;

[0027] Figure 2 This is a schematic diagram of the U-shaped throttling groove valve port structure of the present invention;

[0028] Figure 3 This is a simulation comparison curve diagram of working condition 1 of the present invention;

[0029] Figure 4 This is a simulation comparison curve diagram of working condition 2 of the present invention;

[0030] In the figure, A 1 —The area of ​​the first throttle surface; B 1 —The area of ​​the second throttling surface; R—The radius of the top circle of the U-shaped throttling groove; x—Valve port opening; r—Valve core radius; H—Depth of the U-shaped throttling groove; L—Length of the U-shaped throttling groove. DETAILED DESCRIPTION

[0031] The specific implementation of the present invention will be further described below in conjunction with the accompanying drawings:

[0032] like Figure 1 As shown, the present invention provides a method for measuring flow at a U-shaped throttling groove valve port, comprising the following steps:

[0033] S1), according to the actual size parameters of the U-shaped throttling groove valve port, obtain the throttling area A of the U-shaped throttling groove valve port 1 With throttling area B 1 .

[0034] The U-shaped throttling groove valve port structure is as shown in the attached Figure 2 As shown, from Figure 2 It can be seen that there are two situations when calculating the area of ​​the throttling surface:

[0035] As a preferred embodiment, in step S1), when the valve opening x is smaller than the top circle radius R of the U-shaped throttling groove, the throttling area A 1 With throttling area B 1 The calculation formula is:

[0036]

[0037] Where R is the radius of the top circle of the U-shaped throttling groove, x is the valve opening, r is the valve core radius, and H is the depth of the U-shaped throttling groove.

[0038] Preferably, in step S1), when the valve opening x is greater than or equal to the top circle radius R of the U-shaped throttling groove, the throttling area A 1 With throttling area B 1 The calculation formula is:

[0039]

[0040] Where R is the radius of the top circle of the U-shaped throttling groove, x is the valve opening, r is the valve core radius, and H is the depth of the U-shaped throttling groove.

[0041] S2) Obtain the flow resistance R in each throttling surface zi (i=1,2); specifically: the flow resistance R in each throttling surface zi The calculation method for (i=1,2) is:

[0042]

[0043]

[0044] In the formula, C d1 is the flow coefficient of the first throttling surface, C d2 is the flow coefficient of the second throttling surface, R z1 is the flow resistance in the first throttling surface, R z2 is the flow resistance in the second throttling surface, and ρ is the liquid density.

[0045] S3), according to the flow resistance R z1 and R z2 Get the average flow resistance as the average flow resistance R of the U-shaped throttling groove valve port za The average flow resistance R of the U-shaped throttling groove valve port za The expression is:

[0046]

[0047] S4) The valve port flow formula is used to obtain the actual flow q through the U-shaped throttling slot valve port:

[0048]

[0049] Where Δp is the pressure difference across the U-shaped throttling groove valve port.

[0050] In this embodiment, the flow rate of the U-shaped throttling groove valve port with different size structures is simulated in ANSYS / Fluent to verify the accuracy of the calculation method provided by the present invention. The specific simulation conditions are shown in Table 1.

[0051]

[0052] The comparison curve between the simulation and calculation results of the U-shaped throttling slot valve port flow rate q under different valve port openings x is shown in the figure below. Figure 3 and Figure 4 As shown in the figure, it can be seen that the calculation results are consistent with the simulation results. It can be seen that the U-shaped throttling groove valve port flow calculation formula proposed in the present invention has high accuracy.

[0053] The above embodiments and descriptions are only for illustrating the principles and best embodiments of the present invention. Without departing from the spirit and scope of the present invention, the present invention may be subject to various changes and improvements, all of which fall within the scope of the present invention to be protected.

Claims

1. A method for measuring flow rate of a U-shaped throttling groove valve port, characterized in that: The following steps are involved: S1) According to the actual size parameters of the U-shaped throttling groove valve port, obtain the throttling area of ​​the U-shaped throttling groove valve port A 1 and throttling area B 1; S2) Obtain the flow resistance in each throttling surface ( i =1,2); S3) According to the flow resistance and Get the average flow resistance as the average flow resistance of the U-shaped throttle groove valve port ; S4) The valve port flow formula is used to obtain the actual flow through the U-shaped throttling groove valve port. ; In step S1), when the valve opening x Smaller than the top radius of the U-shaped throttling groove R When the throttling area A 1 and throttling area B The calculation formula of 1 is: ； In the formula, is the top radius of the U-shaped throttling groove, is the valve opening, is the valve core radius, is the depth of the U-shaped throttling groove; In step S1), when the valve opening x Greater than or equal to the radius of the top circle of the U-shaped throttling groove R When the throttling area A 1 and throttling area B The calculation formula of 1 is: ； In the formula, is the top radius of the U-shaped throttling groove, is the valve opening, is the valve core radius, is the depth of the U-shaped throttling groove; The flow resistance of each throttling surface ( i =1,2) is calculated as: ； ； In the formula, is the flow coefficient of the first throttling surface, is the flow coefficient of the second throttling surface, is the flow resistance in the first throttling surface, is the flow resistance in the second throttling surface, is the liquid density; In step S3), the average flow resistance of the U-shaped throttling groove valve port is The expression is: ； In step S4), the actual flow rate through the U-shaped throttling groove valve port for: ； In the formula, It is the pressure difference at both ends of the U-shaped throttling groove valve.

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