CN113251204B - Multi-stage sleeve type high-pressure-difference control valve sleeve structure and design optimization method - Google Patents

Multi-stage sleeve type high-pressure-difference control valve sleeve structure and design optimization method Download PDF

Info

Publication number
CN113251204B
CN113251204B CN202110511968.0A CN202110511968A CN113251204B CN 113251204 B CN113251204 B CN 113251204B CN 202110511968 A CN202110511968 A CN 202110511968A CN 113251204 B CN113251204 B CN 113251204B
Authority
CN
China
Prior art keywords
sleeve
pressure
stage
layer
characteristic curve
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN202110511968.0A
Other languages
Chinese (zh)
Other versions
CN113251204A (en
Inventor
钱锦远
于龙杰
郝娇山
蒋永兵
王伟波
侯聪伟
金志江
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Zhejiang University ZJU
Chongqing Chuanyi Control Valve Co Ltd
Original Assignee
Zhejiang University ZJU
Chongqing Chuanyi Control Valve Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Zhejiang University ZJU, Chongqing Chuanyi Control Valve Co Ltd filed Critical Zhejiang University ZJU
Priority to CN202110511968.0A priority Critical patent/CN113251204B/en
Publication of CN113251204A publication Critical patent/CN113251204A/en
Application granted granted Critical
Publication of CN113251204B publication Critical patent/CN113251204B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
    • F16K47/00—Means in valves for absorbing fluid energy
    • F16K47/08—Means in valves for absorbing fluid energy for decreasing pressure or noise level and having a throttling member separate from the closure member, e.g. screens, slots, labyrinths
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F30/00—Computer-aided design [CAD]
    • G06F30/10—Geometric CAD
    • G06F30/17—Mechanical parametric or variational design
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F30/00—Computer-aided design [CAD]
    • G06F30/20—Design optimisation, verification or simulation
    • G06F30/28—Design optimisation, verification or simulation using fluid dynamics, e.g. using Navier-Stokes equations or computational fluid dynamics [CFD]
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F2111/00—Details relating to CAD techniques
    • G06F2111/10—Numerical modelling
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F2113/00—Details relating to the application field
    • G06F2113/08—Fluids
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F2119/00—Details relating to the type or aim of the analysis or the optimisation
    • G06F2119/08—Thermal analysis or thermal optimisation
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F2119/00—Details relating to the type or aim of the analysis or the optimisation
    • G06F2119/14—Force analysis or force optimisation, e.g. static or dynamic forces

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Geometry (AREA)
  • Theoretical Computer Science (AREA)
  • General Physics & Mathematics (AREA)
  • General Engineering & Computer Science (AREA)
  • Computer Hardware Design (AREA)
  • Pure & Applied Mathematics (AREA)
  • Mathematical Optimization (AREA)
  • Evolutionary Computation (AREA)
  • Mathematical Analysis (AREA)
  • Computational Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Algebra (AREA)
  • Computing Systems (AREA)
  • Fluid Mechanics (AREA)
  • Mathematical Physics (AREA)
  • Lift Valve (AREA)

Abstract

The invention discloses a multi-stage sleeve type high-pressure-difference control valve sleeve structure and a design optimization method. The invention provides a design method of a multi-stage sleeve type high differential pressure control valve sleeve, which comprises the design of the stage number, the thickness and the clearance of the multi-stage sleeve; and the design method of the small holes on the multi-stage sleeve can enable the sleeve control valve to realize specific flow characteristics including linear, quick-opening and equal percentage characteristic curves. The design method of the number and the thickness of the multistage sleeve is based on the working condition that the sleeve faces radial external pressure and the axial pressure on the sleeve; the design method for opening linear, quick-opening and equal percentage characteristic curves is based on computational fluid dynamics software and iterative computation thereof. The invention has the advantages of convenient design, cost saving, capability of quickly and accurately obtaining the multi-stage porous sleeve and certain engineering application value.

Description

Multi-stage sleeve type high-pressure-difference control valve sleeve structure and design optimization method
Technical Field
The invention relates to the field of sleeve type high pressure difference valves, in particular to a structure of a throttling sleeve assembly with liquid working medium and a design optimization method.
Background
Sleeve type control valves have functions of suppressing cavitation and vibration and reducing noise, and change in adjustment characteristics can be realized by replacing sleeve components, and therefore, are widely used as valves such as pressure reducing valves, steam control valves, high-pressure drain valves, and the like, and are also one of important structural types of control valves. Under complex working conditions, the single-layer sleeve is often insufficient in noise reduction capability and cavitation reduction capability, and a multi-layer sleeve is often required to be designed. Further, as one of the important types of control valves, the tuning of sleeve control valves is critical to the accurate tuning of flow characteristics, and reliability under complex operating conditions, for which sleeve-based sleeve assemblies often determine flow capacity within the valve, as well as flow characteristics. In conclusion, the sleeve design research of the multi-stage sleeve valve has very important guiding significance for the application of the sleeve valve.
Through research and study, a design and calculation of a pressure reduction stage number, sleeve thickness and sleeve clearance are provided by a multistage pressure reduction sleeve optimization design method (CN 104214416A), but the calculation of a sleeve structure and a specific flow area is not described, a design formula of the sleeve thickness belongs to the calculation of the inner pressure of the sleeve, and the buckling failure of a sleeve bearing the outer pressure is not considered. The multi-layer sleeve of the high-pressure-difference multi-stage sleeve type control valve usually bears external pressure, however, the deformation and stress conditions of the sleeve bearing the external pressure and the sleeve bearing the internal pressure are different, and the shell can generate plastic deformation until plastic collapse and damage occur; when the external pressure is applied, in addition to the damage phenomenon similar to that of the shell applied with the internal pressure, when the external pressure load is increased to a certain value, the shell is buckled by flattening or folding, and the buckling phenomenon is one of the common forms of the damage of the shell applied with the external pressure. The sleeve type control valve needs accurate adjustment characteristics, but the control valve is often applied to high-parameter working conditions, and the numerical simulation flow design of the sleeve valve gradually shows the advantages of the sleeve valve from the aspects of saving economy and reducing the design difficulty.
In summary, it is highly desirable to provide a sleeve structure for reducing cavitation and noise and a fast and accurate design and calculation method thereof in consideration of the influence of multiple factors on the sleeve structure.
Disclosure of Invention
The invention aims to provide a sleeve structure of a high-pressure-difference multistage sleeve valve and a design method, which are suitable for high pressure difference, have good pressure reduction and flow stabilization effects and achieve good flow regulation performance.
The technical scheme adopted by the invention is as follows:
in a first aspect, the invention provides a multi-stage sleeve type high pressure difference control valve sleeve structure, which is a sleeve assembly arranged between a valve cover and a valve body, wherein the sleeve assembly comprises an upper sleeve, a plurality of layers of sleeves with holes and a lower sleeve bottom; the plurality of layers of sleeves are coaxially nested, the tops of the sleeves are connected to the bottoms of the upper sleeves, and the bottoms of the sleeves are plugged by the lower bottoms of the sleeves; the valve cover is arranged on the valve body and the sleeve assembly, and the valve cover has downward pressing force on the valve body and the sleeve assembly.
In a second aspect, the present invention provides a method for optimizing the design of a sleeve structure of a multi-stage sleeve-type high differential pressure control valve according to the first aspect, which comprises the following steps:
s1, determining the sleeve number n of the multi-stage sleeve type high differential pressure control valve sleeve according to the principle that the pressure drop of each stage of sleeve is required to be smaller than the blocking flow differential pressure, wherein the value interval of n is [2,4 ];
s2, simultaneously considering the radial pressure of the external medium on the sleeve and the axial pressure exerted by the valve cover, calculating the initial thickness t of the first sleeve meeting the radial pressure0And a second sleeve initial thickness t satisfying the axial pressure1Selecting t0And t1The maximum value is taken as the thickness t of each stage of sleeve;
the first sleeve initial thickness t0The solving formula of (2) is as follows:
Figure BDA0003060752670000021
in the formula: the correction coefficient alpha is 1.3-1.6; pcrIs radial critical pressure, MPa; l is the length of the sleeve, mm; d is the outer diameter of the outermost sleeve, mm; e is the Young's modulus of elasticity, MPa, of the sleeve material;
the second sleeve initial thickness t1The solving formula of (2) is as follows:
Figure BDA0003060752670000022
in the formula: fNThe sleeve is subjected to axial pressure from the valve cover in the valve body, N; mu is the Poisson's ratio of the sleeve material;
s3, determining the maximum allowable gap between two adjacent stages of sleeves according to the determined thickness t of each stage of sleeves, and taking the maximum allowable gap as the gap value between two adjacent stages of sleeves;
s4, determining a full-flow coefficient when the sleeve is fully opened according to the target flow characteristic curve of the sleeve, and performing first iteration through computational fluid dynamics software under the condition that the sleeve is supposed to meet the linear flow characteristic to obtain the total flow area S of each stage of sleeve, wherein the full-open flow coefficient of the sleeve is equal to the full-flow coefficientGeneral assembly(ii) a Then the total flow area of the sleeves in each stage is S all the timeGeneral assemblyOn the premise of (1), performing second iteration on the designed layer number, the aperture size and the number of the open pores in each stage of sleeve by computational fluid dynamics software to ensure that when the final flow characteristic curve of the sleeve conforms to the target flow characteristic curve, stopping iteration to obtain the designed layer number, the aperture size and the number of the open pores in each stage of sleeve, and completing design optimization of the sleeve structure of the multi-stage sleeve type high-pressure-difference control valve.
As a preferable mode of the second aspect, in S1, the choke flow pressure difference calculation formula of each stage of the sleeve is:
Figure BDA0003060752670000023
Figure BDA0003060752670000031
p1(i+1)＝p1i-Δpchokedi
in the formula: Δ pchokediChoked flow differential pressure, kPa, for the i-th stage sleeve; i is 1,2, …, n, n is the total number of the sleeve; fLRecovering the coefficient for the pressure; fFIs the liquid critical pressure ratio coefficient; p is a radical of1iThe pressure is the pressure before the ith-stage sleeve, kPa; when i is 1, p1i＝pin；pinValve inlet pressure, kPa; p is a radical ofvIs the absolute pressure of the liquid vapour at the inlet temperature, kPa; p is a radical ofcAbsolute thermodynamic critical pressure, kPa;
as a preferable mode of the second aspect, in S1, the pressure drop calculation formula of each stage of the sleeve is:
Figure BDA0003060752670000032
in the formula: Δ p is the differential pressure across the valve, Δ p ═ pin-pout，kPa；poutValve outlet pressure, kPa; Δ p2iThe estimated i-th stage sleeve pressure drop, kPa.
Preferably, in the second aspect, the number of rows of the openings in the sleeve is an even number.
Preferably, in the second aspect, there is no idle stroke between the upper and lower layers of openings in the sleeve, the diameter of each layer of openings is the height of the layer of openings, and the total length of all layers is the valve stroke.
Preferably, in the second aspect, in S4, the target flow rate characteristic curve of the sleeve is a linear flow rate characteristic curve, and the aperture of the openings of any upper and lower layers is the same when the second iteration is performed.
Preferably, in the second aspect, in S4, the target flow characteristic curve of the sleeve is a quick-opening flow characteristic curve, and when performing the second iteration, the aperture of the next layer of the openings is not smaller than the aperture of the previous layer of the openings.
Preferably, in the second aspect, in S4, the target flow characteristic curve of the sleeve is an equal percentage flow characteristic curve, and when performing the second iteration, it is satisfied that, in any two adjacent layers of openings, the aperture of the opening in the next layer is not larger than the aperture of the opening in the previous layer.
In a third aspect, the invention provides a multi-stage sleeve type high differential pressure control valve sleeve structure which is obtained by optimizing the design of the method according to any scheme in the second aspect.
The invention has the beneficial effects that:
the sleeve structure of the high-pressure-difference multistage sleeve valve with the structure can be designed into different flow characteristic curves according to different opening modes, and the flow characteristic curves of the valve are divided into quick opening, linearity, equal percentage and the like. The sleeve thickness design method can ensure that the sleeve can keep a stable state under the condition of bearing radial external pressure and axial external pressure, and is convenient to calculate. The multistage sleeve designed by the invention has good noise reduction and flow stabilization effects.
Drawings
In order that the disclosure of the invention may be more readily understood, reference is now made to the following detailed description of the invention taken in conjunction with the accompanying drawings and examples, in which:
figure 1 is a block diagram of a geometric cross-section of a sleeve valve.
FIG. 2 is a partial detail view of the sleeve assembly.
Fig. 3 is a plan view of the linear flow rate characteristic sleeve in the embodiment.
Fig. 4 is a plan expanded view of the quick-opening flow rate characteristic sleeve in the embodiment.
FIG. 5 is a plan expanded view of an equal percentage flow characteristic sleeve in an example embodiment.
Fig. 6 is a numerical simulation verification diagram of the design structure a and the like in the example.
Fig. 7 is a numerical simulation verification diagram of the equivalent percent flow characteristics of the improved structure B in the example.
Fig. 8 is a numerical simulation verification diagram of the equivalent percent flow characteristics of the improved structure C in the example.
The reference numbers in the figures are:
1. a valve cover; 2. a valve body; 3. a sleeve assembly; 31. an upper sleeve; 32. a first layer of apertured sleeve; 33. a second layer of perforated sleeves; 34. a third layer of perforated sleeve; 35. the lower bottom of the sleeve.
Detailed Description
The invention will be described in further detail below with reference to the drawings, but the scope of the invention is not limited thereto.
As shown in fig. 1, the multi-stage sleeve type high differential pressure control valve structure mainly comprises a valve cover 1, a valve body 2 and a sleeve component 3. The sleeve structure of the multistage sleeve type high differential pressure control valve is the sleeve component 3 arranged between the valve cover 1 and the valve body 2. The sleeve assembly 3 is integrally located in the valve body 2 and comprises an upper sleeve 31, an open sleeve and a lower sleeve bottom 35. The sleeve has multiple layers, and the total number of the sleeve layers is the number of the sleeve stages. The multiple layers of sleeves are coaxially nested, the tops of the multiple layers of sleeves are connected to the bottom of the upper sleeve 31, and the bottoms of the multiple layers of sleeves are plugged by the lower bottom 35 of the sleeve. In addition, the valve cover 1 is disposed on the valve body 2 and the sleeve assembly 3, and the valve cover 1 has a downward pressing force on the valve body 2 and the sleeve assembly 3.
As shown in fig. 2, the sleeve structure of the multi-stage sleeve type high differential pressure control valve with 3 layers of sleeves is a form of a sleeve structure, and the sleeve structure comprises an upper sleeve 31, a first layer of perforated sleeves 32, a second layer of perforated sleeves 33, a third layer of perforated sleeves 34 and a sleeve lower bottom 35. The first layer of perforated sleeve 32, the second layer of perforated sleeve 33 and the third layer of perforated sleeve 34 are all connected with the upper sleeve 31 and the lower sleeve bottom 35 through welding.
Of course, the specific number of sleeve layers in the sleeve structure of the multistage sleeve type high differential pressure control valve needs to be optimized according to the subsequent design method of the invention, and the 3-layer sleeve is only one of the forms. The invention provides a design optimization method of a sleeve structure of a multi-stage sleeve type high-pressure-difference control valve, which comprises the following steps:
s1: socket number of stages calculation
According to the standard GB/T17213.2-2017, when controlling valves and accessoriesWhen the pipe fittings have the same size, (F)LP/FP)2Simplified to (F)L)2Thus, the per-stage sleeve choked flow differential is calculated as follows:
Figure BDA0003060752670000051
the calculation formula of the blocking flow pressure difference of each stage of sleeve is as follows:
Figure BDA0003060752670000054
Figure BDA0003060752670000052
p1(i+1)＝p1i-Δpchokedi
the pressure difference estimation formula of each stage of sleeve is as follows:
Figure BDA0003060752670000053
Δpchokedi-choked flow differential pressure, kPa, of the i-th stage sleeve;
Δ p-differential pressure across the valve, Δ p ═ pin-pout,kPa；
pin-valve inlet pressure, kPa;
pout-valve outlet pressure, kPa;
Δp2i-estimated pressure drop, kPa, for the i-th stage sleeve;
p1i-front pressure of i stage sleeve, kPa; when i is 1, p1i＝pin；
pv-absolute pressure of liquid vapour at inlet temperature, kPa;
pc-absolute thermodynamic critical pressure, kPa;
n is the total number of the sleeve;
i-represents the stage number sleeve;
FL-a pressure recovery coefficient, determined according to the standard GB/T17213.2-2017;
FFthe critical pressure ratio coefficient of the liquid, the ratio of the significant "Vena Contracta" pressure of the choked flow to the vapor pressure of the liquid at the inlet temperature, is 0.96 when the vapor pressure is near zero.
Calculating the choked flow pressure difference of the sleeve of each stage and estimating the pressure drop of each stage according to the formula, wherein the pressure drop of each stage is less than the choked flow pressure difference of each stage, namely delta p2i≤ΔpchokediAnd a proper sleeve number n can be selected, wherein the sleeve number n does not exceed four layers, so that the selection interval of n is 2, 3 and 4.
S2: design of sleeve thickness
After the number n of the sleeve stages is determined, the thickness of the sleeve and the gap between two adjacent layers of sleeves can be designed, and the gaps between any two adjacent layers of sleeves are equal in the embodiment.
The design formula of the sleeve thickness in the prior art is based on the condition that the sleeve is subjected to internal pressure, but the fact that the multi-layer sleeve of the multi-stage sleeve type control valve with high differential pressure usually bears external pressure. The deformation and stress conditions of the sleeve bearing external pressure and internal pressure are different, the shell can generate plastic deformation until plastic collapse damage occurs, and the failure is represented by axial cracks on the sleeve wall; when the external pressure load of the sleeve bearing external pressure is increased to a certain value, the shell has buckling phenomena such as flattening or wave folding, and the buckling phenomena is one of common forms of the external pressure shell damage. Therefore, the invention is based on the condition that the sleeve is subjected to external pressure, and mainly checks the buckling failure mode, so that the designed sleeve is more scientific.
Specifically, the radial pressure of the external medium on the sleeve and the axial pressure exerted by the valve cover need to be considered simultaneously, and the initial thickness t of the first sleeve meeting the radial pressure is calculated0And a second sleeve initial thickness t satisfying the axial pressure1The larger is used as the final sleeve thickness.
In one aspect, the barrel knotThe sleeve is symmetrically pressed in the circumferential direction, the external medium generates radial pressure on the sleeve, and the initial thickness t meeting the radial pressure can be calculated according to the following formula0：
Figure BDA0003060752670000061
Alpha is 1.3-1.6
On the other hand, the sleeve can receive the pressure F from the valve cover in the valve bodyNThe pressure is an engineering prediction, and the initial thickness t of the second sleeve can be calculated by the pressure1。
Stress sigma of sleeve bearing axial pressure1The approximate calculation formula is:
Figure BDA0003060752670000062
the approximate calculation formula of the critical stress of the sleeve bearing the axial pressure is as follows:
Figure BDA0003060752670000063
σcr＝σ1
in the formula:
FN-estimating the axial pressure, N;
E-Young's modulus of elasticity, MPa, of the sleeve material;
d is the outer diameter of the outermost sleeve, mm;
l is the length of the sleeve, mm;
t is the wall thickness of the sleeve, mm;
μ — Poisson's ratio of the sleeve material;
σcr-axial critical stress, MPa;
Pcr-radial critical pressure, MPa; the value here is the pressure difference between the inside and the outside of each stage of the sleeve.
Thus, by combining the above equations, the initial thickness of the second sleeve can be solvedDegree t1. For simplifying engineering treatment, t is taken0And t1The maximum value of the thickness t is used as the sleeve thickness t, so that the sleeve thickness can meet corresponding requirements.
The thickness t of each stage of sleeve can be calculated according to the method, and the thicknesses of the sleeves of each stage can be consistent or inconsistent. In this embodiment, the thicknesses of the sleeves of different levels are all the same, so that the thickness of all the sleeves can be obtained by selecting the maximum value of the thickness t of the sleeve in each level.
The correction coefficient alpha in the invention can correct the radial critical pressure pcrThe invention therefore simultaneously considers the sleeve being subjected to an axial pressure FNAnd the influence of medium external pressure, solving t according to the formulas, namely, solving the comprehensive consideration result of compression resistance and buckling deformation, and better ensuring that the structural strength of the sleeve meets the use requirement.
S3: sleeve gap design
The larger the gap of the sleeve is, the more beneficial the pressure reduction and the flow stabilization are. After the sleeve thickness t is determined, the maximum value can be selected as much as possible by selecting the sleeve clearance under the condition that the sleeve thickness is ensured to meet the requirement. In this embodiment, the gap value between any two adjacent stages of sleeves is kept consistent.
S4: sleeve opening design
The sleeve openings directly affect the flow area and flow characteristics. In the invention, the design and calculation principle of the flow area is as follows:
(1) the hole opening mode designed aiming at linearity, quick opening and equal percentage mainly adopts 'evenly distributed up and down', 'dense lower part and sparse upper part' and 'dense lower part and dense upper part'.
(2) The number of the rows of the openings which can be selected is 4 rows, 6 rows, 8 rows, 10 rows, … … 24 rows, … … (even rows), and the parameter is selected in such a way that the number of the openings in each layer is xkOpening size r of each layerkThe number of layers from top to bottom is K.
(3) And selecting a curve of a specific flow characteristic curve, extracting the flow coefficient under the opening degree, and avoiding the idle stroke and the situation that holes exist or are tangent to the holes in each opening degree, wherein the idle stroke cannot occur between the upper layer of holes and the lower layer of holes. And the aperture of each layer of opening is the height of the layer of opening, and the total length of all the layers of openings along the height direction is the valve stroke.
Therefore, the sleeve hole design method of the invention is as follows:
firstly, acquiring a target flow characteristic curve which is finally expected to be obtained by the sleeve according to design requirements, and determining a full-circulation flow coefficient when the sleeve is fully opened according to the target flow characteristic curve of the sleeve; then, under the condition that the sleeve meets the linear flow characteristic, the first iteration is carried out through computational fluid dynamics software to obtain the total flow area S of each stage of sleeve, wherein the total open flow coefficient of the sleeve is equal to the total flow coefficientGeneral assembly(ii) a Finally, the total flow area of each stage of sleeve is S all the timeGeneral assemblyOn the premise of (1), performing second iteration on the designed layer number, the aperture size and the number of the open pores in each stage of sleeve by computational fluid dynamics software to ensure that when the final flow characteristic curve of the sleeve conforms to the target flow characteristic curve, stopping iteration to obtain the designed layer number, the aperture size and the number of the open pores in each stage of sleeve, and completing design optimization of the sleeve structure of the multi-stage sleeve type high-pressure-difference control valve.
The computational fluid dynamics software used in the present embodiment is Fluent software, but may be implemented by other software.
It should be noted that the first iteration is only performed to obtain the total flow area S of the sleeve of each stageGeneral assemblyThe full-open flow coefficient of the sleeve is equal to the full-flow coefficient, but the flow characteristic curve does not necessarily conform to the target flow characteristic curve at other non-full-open openings. Based on the principle that the change of the flow coefficient along with the opening degree is equal to the change of the sectional area along with the opening degree, the total flow area S of each stage of sleeve can be obtained through the first iterationGeneral assemblyAnd, whether or not the target flow rate characteristic curve is a linear flow rate characteristic curve, it may be assumed to be a linear flow rate characteristic curve. That is, the fast opening flow characteristic curve and the equal percentage characteristic curve hole opening mode can also be designed based on the hole opening mode of calculating the full opening linear characteristic curve, and the total flow area S of each stage of sleeve is determinedGeneral assemblyAnd then the second iteration is carried out to design the layer number, the aperture size and the aperture by adjustingThe number of the holes is further used for enabling the flow coefficient under other opening degrees to meet the target flow characteristic curve.
The following rules for designing the openings are respectively explained for three forms (linear, quick opening, equal percentage) of the target flow characteristic curve:
if the target flow characteristic curve of the sleeve is a linear flow characteristic curve, the aperture of any upper layer of open pores and any lower layer of open pores are the same when the second iteration is carried out.
If the target flow characteristic curve of the sleeve is a quick-opening flow characteristic curve, the requirement that the aperture of the next layer of open pores is not smaller than that of the previous layer of open pores in any two adjacent layers of open pores is met during the second iteration.
If the target flow characteristic curve of the sleeve is the equal percentage flow characteristic curve, the requirement that the aperture of the next layer of open pores is not larger than that of the previous layer of open pores in any two adjacent layers of open pores is met during the second iteration.
The total design layer number K of the holes on each stage of sleeve can be preset and is generally within the range of 10-15 layers.
In this embodiment, the specific design method of the three types of sleeves is as follows:
(1) linear flow characteristic curve opening design
The linear characteristic curve has the opening mode shown in fig. 3, the sizes of the openings in one layer are consistent, the size distribution of the openings is 'consistent up and down', no idle stroke exists between each dotted line, and fluid flows through each small stroke. Preliminary estimation of the pore diameter r0The value is empirically estimated, iterative trial calculation is carried out through computational fluid dynamics software until the simulated full-open flow coefficient is equal to the linear full-open flow coefficient, and C is metvLinear ═ CvAnd simulating, and designing according to the total flow area of each stage to obtain the number and the aperture of the openings of each layer:
Figure BDA0003060752670000081
the number of the hole opening layers from bottom to top is recorded as 1 to K layers, each layer is sequentially arranged, and the total length of all the layers is the stroke of the valve. And for any kth layer, the pore size distribution satisfies:
rk＝rk+1
the regulation intensity is recorded as F, the change of the flow coefficient along with the opening is equal to the change of the sectional area along with the opening, and the formula can be deduced according to the assumption that
Figure BDA0003060752670000091
And designing the number of layers and the size and the number of the small holes in each layer according to the formula, and iteratively calculating the flow characteristic of the initially designed sleeve by adopting computational fluid dynamics software. In the iteration process, the number of designed layers and the size of each layer of small holes can be kept unchanged, the number of the small holes in the deviation layer is changed only for the area with large deviation in the curve, and the iterative calculation is carried out until the precision meets the requirement. Namely, when the final flow characteristic curve of the sleeve accords with the target flow characteristic curve, the iteration is stopped to obtain the designed layer number, the aperture size and the number of the holes in each stage of the sleeve, and the design optimization (2) of the sleeve structure of the multi-stage sleeve type high differential pressure control valve and the design of the quick-opening flow characteristic curve open hole can be completed by combining the sleeve thickness, the clearance and other parameters
The hole opening mode of the quick opening flow characteristic curve is as shown in fig. 4, the sizes of holes in one layer are consistent, the hole size distribution is 'big end down', no idle stroke exists between each dotted line, and fluid flows through each section of small stroke. And designing a full-flow coefficient under the full-open linear characteristic opening according to S6, wherein the full-open linear flow coefficient is equal to the full-open quick-opening flow coefficient, and the design is carried out according to the total flow area of each stage.
CvLinear ═ CvQuick-opening device
Figure BDA0003060752670000092
The number of the hole opening layers from bottom to top is recorded as 1 to K layers, each layer is sequentially arranged, and the total length of all the layers is the stroke of the valve. And for any kth layer, the pore size distribution satisfies:
rk≥rk+1
the regulation intensity is recorded as F, the change of the flow coefficient along with the opening is equal to the change of the sectional area along with the opening, and the formula can be deduced according to the assumption that
Figure BDA0003060752670000093
According to the formula, the number of layers and the size and the number of small holes in each layer are designed, and the flow characteristic of the sleeve is preliminarily designed by adopting computational fluid dynamics software. In the iteration process, the number of designed layers and the size of each layer of small holes can be kept unchanged, the number of the small holes in the deviation layer is changed only for the area with large deviation in the curve, and the iterative calculation is carried out until the precision meets the requirement. Namely, when the final flow characteristic curve of the sleeve accords with the target flow characteristic curve, the iteration is stopped to obtain the designed layer number, the aperture size and the number of the holes in each stage of the sleeve, and the design optimization of the sleeve structure of the multi-stage sleeve type high differential pressure control valve can be completed by combining the sleeve thickness, the clearance and other parameters
(3) Equal percentage characteristic curve flow design
The hole opening mode of the quick opening flow characteristic curve is as shown in fig. 5, the sizes of holes in one layer are consistent, the hole sizes are distributed in a large-upper mode and a small-lower mode, no idle stroke exists between each dotted line, and fluid flows through each section of small stroke. The full flow coefficient under the full-open linear characteristic opening is designed according to S6, the full-open equal percentage flow coefficient is equal to the full-open equal percentage flow coefficient according to the full-open linear characteristic opening, and the following design is carried out according to the total flow area of each stage.
CvLinear ═ CvEqual percentage of
Figure BDA0003060752670000101
The number of the hole opening layers from bottom to top is recorded as 1 to K layers, each layer is sequentially arranged, and the total length of all the layers is the stroke of the valve. And for any kth layer, the pore size distribution satisfies:
rk≤rk+1
the regulation intensity is recorded as F, the change of the flow coefficient along with the opening is equal to the change of the sectional area along with the opening, and the formula can be deduced according to the assumption that
Figure BDA0003060752670000102
And designing the number of layers and the size and the number of the small holes in each layer according to the formula, and iteratively calculating the flow characteristic of the initially designed sleeve by adopting computational fluid dynamics software. In the iteration process, the number of designed layers and the size of each layer of small holes can be kept unchanged, the number of the small holes in the deviation layer is changed only for the area with large deviation in the curve, and the iterative calculation is carried out until the precision meets the requirement. Namely, when the final flow characteristic curve of the sleeve accords with the target flow characteristic curve, the iteration is stopped to obtain the designed layer number, the aperture size and the number of the holes in each stage of the sleeve, and the design optimization of the sleeve structure of the multi-stage sleeve type high differential pressure control valve can be completed by combining the sleeve thickness, the clearance and other parameters
To further illustrate the technical effect of the method, specific design examples and results are given below for the flow of the equivalent percentage characteristic curve.
Designing a target: the caliber is 100mm, the stroke is 38mm, the flow is 54Kg/s, the diameter D of the outermost sleeve is 144, the number n of the cylinder stages is 3, the thickness t of the sleeve is 2mm, the pressure difference delta p between an inlet and an outlet is 10MPa, and the design adjustable ratio R is 50: 1 flow rate characteristic curve.
Through preliminary trial calculation of S4, the initial aperture r04mm, and a pore number of 60, the flow rate is closest to 54Kg/s, so that the pore diameter r of the small pores ranges from (r) based on the flow rate0/2—r0)＝(2—4mm)，SGeneral assembly＝752mm2. The structure A is designed by converting the strength F, and because the small opening is not adjustable, a hole is not formed in the sleeve with the height of 0-2mm, and the sleeve with the height of 2-4mm is used as a first layer of hole.
TABLE 1 design Structure A parameter map
Number of layers Height of hole Pore diameter h/hmax q/qmax Sk/SGeneral assembly Number of holes in each layer Round and tidy
1 4mm 2mm 0.105263 0.01671 0.01671 4.6788 4
2 6mm 2mm 0.157895 0.02081 0.0041 1.148 4
3 8mm 2mm 0.210526 0.029 0.00819 2.2932 2
4 10mm 2mm 0.263158 0.03925 0.01025 2.87 4
5 12mm 2mm 0.315789 0.05348 0.01423 3.9844 4
6 14mm 2mm 0.368421 0.06996 0.01648 4.6144 4
7 16mm 2mm 0.421053 0.09244 0.02248 6.2944 6
8 18mm 2mm 0.473684 0.11093 0.01849 5.1772 8
9 20mm 2mm 0.526316 0.13541 0.02448 6.8544 8
10 22mm 2mm 0.578947 0.16828 0.03287 9.2036 8
11 25mm 3mm 0.657895 0.23382 0.06554 8.1560 8
12 28mm 3mm 0.736842 0.34032 0.1065 13.253 14
13 31mm 3mm 0.815789 0.46692 0.1266 15.754 16
14 34mm 3mm 0.894737 0.67658 0.20966 26.091 24
15 38mm 4mm 1 1 0.32342 24 24
Through modeling, a flow rate characteristic curve is calculated by trial, and the calculation result shows that the deviation exists between the standard characteristic curve and the flow rate characteristic curve under different opening degrees as shown in fig. 6. Therefore, the number of holes at the deviated opening degree (i.e., deviated layer) was adjusted based on the design structure a, and trial calculation was performed again to obtain the improved design structure B, and as a result, a great improvement was found as shown in fig. 7. The number of holes at the deviation opening (i.e., deviation layer) was adjusted again, and trial calculation was performed again to obtain a further improved design structure C, and as a result, as shown in fig. 8, it was found that the final flow rate characteristic curve achieved the accuracy requirement.
In conclusion, the design method for the number and the thickness of the multistage sleeve is designed aiming at the linear, quick-opening and equal-percentage characteristic curve hole opening based on the working condition that the sleeve faces radial external pressure and the axial pressure applied to the sleeve, iterative calculation is carried out by utilizing computational fluid mechanics software, and quick and stable calculation can be realized. Therefore, the invention has the advantages of convenient design, cost saving, capability of quickly and accurately obtaining the multi-stage porous sleeve and certain engineering application value.

Claims (9)

1. A design optimization method for a multi-stage sleeve type high differential pressure control valve sleeve structure is characterized in that the multi-stage sleeve type high differential pressure control valve sleeve structure is a sleeve component (3) arranged between a valve cover (1) and a valve body (2), and the sleeve component (3) comprises an upper sleeve (31), a plurality of layers of sleeves with holes and a sleeve lower bottom (35); the plurality of layers of sleeves are coaxially nested, the tops of the sleeves are connected to the bottoms of the upper sleeves (31), and the bottoms of the sleeves are plugged by the lower bottoms (35) of the sleeves; the valve cover (1) is arranged on the valve body (2) and the sleeve component (3), and the valve cover (1) has downward pressing force on the valve body (2) and the sleeve component (3);
the design optimization method comprises the following steps:
s1, determining the sleeve number n of the multi-stage sleeve type high differential pressure control valve sleeve according to the principle that the pressure drop of each stage of sleeve is required to be smaller than the blocking flow differential pressure, wherein the value interval of n is [2,4 ];
s2, simultaneously considering the radial pressure of the external medium on the sleeve and the axial pressure exerted by the valve cover, calculating the initial thickness t of the first sleeve meeting the radial pressure0And a second sleeve initial thickness t satisfying the axial pressure1Selecting t0And t1The maximum value is taken as the thickness t of each stage of sleeve;
the first sleeve initial thickness t0The solving formula of (2) is as follows:
Figure FDA0003454611770000011
in the formula: the correction coefficient alpha is 1.3-1.6; pcrIs radial critical pressure, MPa; l is the length of the sleeve, mm; d is the outer diameter of the outermost sleeve, mm; e is the Young's modulus of elasticity, MPa, of the sleeve material;
the second sleeve initial thickness t1The solving formula of (2) is as follows:
Figure FDA0003454611770000012
in the formula: fNThe sleeve is subjected to axial pressure from the valve cover in the valve body, N; mu is the Poisson's ratio of the sleeve material;
s3, determining the maximum allowable gap between two adjacent stages of sleeves according to the determined thickness t of each stage of sleeves, and taking the maximum allowable gap as the gap value between two adjacent stages of sleeves;
s4, determining a full-flow coefficient when the sleeve is fully opened according to a target flow characteristic curve of the sleeve, and performing first iteration through computational fluid dynamics software under the condition that the sleeve is supposed to meet linear flow characteristics to obtain the total flow area S of each stage of sleeve required when the full-open flow coefficient of the sleeve is equal to the full-flow coefficientGeneral assembly(ii) a Then the total circulation of the sleeves at each stageArea is always SGeneral assemblyOn the premise of (1), performing second iteration on the designed layer number, the aperture size and the number of the open pores in each stage of sleeve by computational fluid dynamics software to ensure that when the final flow characteristic curve of the sleeve conforms to the target flow characteristic curve, stopping iteration to obtain the designed layer number, the aperture size and the number of the open pores in each stage of sleeve, and completing design optimization of the sleeve structure of the multi-stage sleeve type high-pressure-difference control valve.
2. The design optimization method of claim 1, wherein in S1, the choke flow pressure difference calculation formula for each stage of the sleeve is:
Figure FDA0003454611770000021
Figure FDA0003454611770000022
p1(i+1)＝p1i-Δpchokedi
in the formula: Δ pchokediChoked flow differential pressure, kPa, for the i-th stage sleeve; i is 1,2, …, n, n is the total number of the sleeve; fLRecovering the coefficient for the pressure; fFIs the liquid critical pressure ratio coefficient; p is a radical of1iThe pressure is the pressure before the ith-stage sleeve, kPa; when i is 1, p1i＝pin；pinValve inlet pressure, kPa; p is a radical ofvIs the absolute pressure of the liquid vapour at the inlet temperature, kPa; p is a radical ofcIs the absolute thermodynamic critical pressure, kPa.
3. The design optimization method of claim 2, wherein in S1, the pressure drop calculation formula for each stage of the sleeve is:
Figure FDA0003454611770000023
in the formula: deltap is the differential pressure before and after the valve, and delta p is pin-pout，kPa；poutValve outlet pressure, kPa; Δ p2iThe estimated i-th stage sleeve pressure drop, kPa.
4. The design optimization method of claim 1, wherein the number of rows of openings in the sleeve is an even number of rows.
5. The design optimization method of claim 1, wherein no idle stroke exists between the upper and lower layers of openings in the sleeve, the diameter of each layer of openings is the height of the layer of openings, and the total length of all layers is the valve stroke.
6. The design optimization method of claim 1, wherein in S4, the target flow characteristic curve of the sleeve is a linear flow characteristic curve, and the second iteration is performed such that the apertures of the openings of any upper layer and any lower layer are the same.
7. The design optimization method of claim 1, wherein in S4, the target flow characteristic curve of the sleeve is a fast-opening flow characteristic curve, and the second iteration is performed such that the aperture of the next layer of the openings is not smaller than the aperture of the previous layer of the openings.
8. The design optimization method of claim 1, wherein in S4, the target flow characteristic curve of the sleeve is an equal percentage flow characteristic curve, and the second iteration is performed such that the aperture of the next layer of openings is not larger than the aperture of the previous layer of openings.
9. A multi-stage sleeve type high differential pressure control valve sleeve structure which is designed and optimized according to the method of any one of claims 1 to 8.
CN202110511968.0A 2021-05-11 2021-05-11 Multi-stage sleeve type high-pressure-difference control valve sleeve structure and design optimization method Active CN113251204B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202110511968.0A CN113251204B (en) 2021-05-11 2021-05-11 Multi-stage sleeve type high-pressure-difference control valve sleeve structure and design optimization method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202110511968.0A CN113251204B (en) 2021-05-11 2021-05-11 Multi-stage sleeve type high-pressure-difference control valve sleeve structure and design optimization method

Publications (2)

Publication Number Publication Date
CN113251204A CN113251204A (en) 2021-08-13
CN113251204B true CN113251204B (en) 2022-02-18

Family

ID=77224014

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202110511968.0A Active CN113251204B (en) 2021-05-11 2021-05-11 Multi-stage sleeve type high-pressure-difference control valve sleeve structure and design optimization method

Country Status (1)

Country Link
CN (1) CN113251204B (en)

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN2530109Y (en) * 2001-12-27 2003-01-08 工装自控工程（无锡）有限公司 High pressure-gradient valve
US8613267B1 (en) * 2011-07-19 2013-12-24 Lightsail Energy, Inc. Valve
CN103821979A (en) * 2014-02-25 2014-05-28 杭州杭氧工装泵阀有限公司 Multistage depressurization valve
CN203743551U (en) * 2014-02-25 2014-07-30 杭州杭氧工装泵阀有限公司 Multistage pressure reducing valve
CN104295752B (en) * 2014-10-09 2017-02-15 兰州理工大学 Multistage step-down sleeve adjusting valve
CN108757976B (en) * 2018-07-12 2020-11-13 铜陵天海流体控制股份有限公司 Three-stage pressure reduction type equal percentage characteristic regulating control valve for boiler system
CN110185842B (en) * 2019-05-24 2020-09-01 浙江大学 Method for optimizing structural parameters of multistage pressure reduction sleeve in high-pressure-difference regulating valve
CN112434417A (en) * 2020-11-20 2021-03-02 哈尔滨汽轮机厂有限责任公司 Intelligent calculation method for strength of sleeve of steam turbine valve

Also Published As

Publication number Publication date
CN113251204A (en) 2021-08-13

Similar Documents

Publication Publication Date Title
CN110185842B (en) Method for optimizing structural parameters of multistage pressure reduction sleeve in high-pressure-difference regulating valve
CN104302907B (en) Pressure limiting valve
JP5069318B2 (en) Ball seat valve with reduced erosion
US20040118462A1 (en) Control valve with low noise and enhanced flow characteristics
EP0857271B1 (en) Flow control valve with non-plugging multi-stage valve trim
CN113251204B (en) Multi-stage sleeve type high-pressure-difference control valve sleeve structure and design optimization method
CN105222383B (en) The control method of heat pump and heat pump
TWI686560B (en) Condensate discharge device
WO2015185303A1 (en) Supercharged internal combustion engine
JP5325306B2 (en) Fuel injection system
CN207005363U (en) Throttling one-way valve
WO2000061975A1 (en) High differential pressure regulating valve
US7305763B2 (en) Hydroformed port liner
CN205479490U (en) Slidingtype diverter valve and cooling cycle system
CN111720568A (en) Valve cage composite structure for stepped pressure reduction and regulating valve for installing valve cage composite structure
CN209839190U (en) Valve cage composite structure for stepped pressure reduction and regulating valve for installing valve cage composite structure
JP5040928B2 (en) Accumulator and method for manufacturing the same
JP6855582B2 (en) High pressure accumulator for fuel high pressure injection system
US20100258656A1 (en) Means for aligning and pre-stressing components of a fuel injector assembly
Kim et al. A study on structural analysis of globe valve for LNG carrier
CN110939557B (en) Compressor flow regulating mechanism and method
JP2904766B1 (en) High differential pressure valve
JP5058140B2 (en) Orifice damping member
TR201820749A2 (en) A FUEL FLOW PATH FOR A FUEL INJECTOR'S VALVE GROUP
CN107091140A (en) Vehicle urea filler counter-jetting resistance structure

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant