Compressor for controlling polynomial membrane cavity molded line based on variable factor and design method

Abstract

The invention discloses a compressor based on a variable factor control polynomial mold cavity molded line and a design method, the compressor is provided with a mold cavity designed and processed based on the variable factor control polynomial molded line, and the variable factor control polynomial molded line is formed by continuously connecting a first polynomial molded line L1 and a second polynomial molded line L2. The connection point of the first polynomial molded line L1 and the second polynomial molded line L2 is defined as a molded line generation point P, the position and inclination angle characteristics of the molded line generation point P are used as generation characteristics of the mold cavity molded line L, and the maximum radius Rmax and the maximum deflection Hmax of the mold cavity molded line L are adjusted by controlling the position coordinates of the molded line generation point P and the inclination angle delta theta of the molded line inflection point, so that the mold cavity molded line L is generated. And the set diaphragm cavity volume and the diaphragm compressor diaphragm cavity molded line meeting the allowable stress condition are obtained. Optimization parameters in the molded line design process can be enriched, the optimization range is expanded, the design flexibility of the diaphragm compressor is improved, diversified market requirements are met, the reliability of the diaphragm compressor is enhanced, and the service life of the diaphragm is prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of diaphragm compressors, and in particular to a compressor based on variable factor control of polynomial diaphragm cavity profiles and a design method thereof. Background Art

[0002] A diaphragm compressor is a positive displacement compressor that uses a diaphragm to separate the oil side and the gas side. Its working principle is: the motor drives the crankshaft connecting rod to drive the piston to reciprocate to achieve pressurization and decompression of the high-pressure oil, and then the high-pressure oil pushes the diaphragm to achieve gas compression and discharge. Diaphragm compressors are widely used in the hydrogen energy industry due to their good sealing and high pressure ratio. In particular, hydrogen refueling stations are one of their important usage scenarios. The diaphragm life, volumetric efficiency and membrane head strength are very critical and difficult issues in the development of diaphragm compressors.

[0003] The diaphragm is a key component in the stable operation of the diaphragm compressor, and its working performance can directly affect the reliability of the compressor operation. In the process of diaphragm damage, the damage forms mainly include collapse, distortion, wear and tear, and mechanical fatigue. Diaphragm damage will lead to the destruction of the mechanical properties of the diaphragm compressor, and even cause greater economic losses in severe cases.

[0004] At present, the diaphragm compressor diaphragm cavity profile widely used in China is the single-exponential small deflection diaphragm cavity profile. After long-term practice and verification, it has good reliability and practical basis. However, in the process of developing and designing new diaphragm compressor models, the traditional single-exponential diaphragm cavity profile is adjusted by three profile variables: diaphragm cavity radius, single exponent and maximum deflection. The profile optimization range is limited, and it is difficult to adjust the diaphragm stress changes caused by the change in the slope of the inflection point of the diaphragm cavity profile. Therefore, it cannot meet the urgent needs of the market demand for the development of diaphragm compressor technology and the development of new high-pressure and high-speed models. Multi-parameter diaphragm cavity profile optimization design is an effective way to improve the reliability of diaphragm compressors and reduce costs. Summary of the invention

[0005] The purpose of the present invention is to address the problems in the above-mentioned prior art and provide a compressor and design method based on variable factor control of polynomial diaphragm cavity profile, enrich the optimization parameters in the profile design process, expand the optimization range, improve the design flexibility of diaphragm compressors, meet diverse market demands, enhance the reliability of diaphragm compressors and increase the life of the diaphragm.

[0006] In order to achieve the above object, the present invention has the following technical solutions:

[0007] A compressor based on variable factor controlled polynomial diaphragm cavity profile, comprising a diaphragm cavity designed and processed based on the variable factor controlled polynomial profile, wherein the variable factor controlled polynomial profile is formed by continuously connecting a first polynomial profile L1 and a second polynomial profile L2, defining the connecting point of the first polynomial profile L1 and the second polynomial profile L2 as a profile generating point P, taking the position and inclination characteristics of the profile generating point P as generating features of the diaphragm cavity profile L, and controlling the position coordinate (x P ,y P ) and the inflection point angle Δθ of the profile, adjust the maximum radius R of the membrane cavity profile L max and the maximum deflection H max , obtain the diaphragm compressor diaphragm cavity profile that sets the diaphragm cavity volume and satisfies the allowable stress conditions.

[0008] As a preferred solution, any point in the first quadrant is used as the profile generating point P in the XOY coordinate system. The inclination angle of the profile generating point P in the XOY coordinate system is the profile inflection point inclination angle Δθ. max , maximum deflection H max , the starting position of the first polynomial line L1 is placed at the XOY coordinate origin O, and the starting position of the second polynomial line L2 is constrained by the line end position of the first polynomial line L1, then the initial conditions for generating the membrane cavity line L are set as follows:

[0009]

[0010] Wherein, R represents the radius of the corresponding membrane cavity line segment; x and y represent the coordinates of the corresponding membrane cavity line in the XOY coordinate system.

[0011] As a preferred solution, the expressions for defining the first polynomial profile L1 and the second polynomial profile L2 are as follows:

[0012]

[0013] Wherein, a and b are line parameters of the first polynomial line L1 and the second polynomial line L2 respectively, and the number of line parameters of the first polynomial line L1 and the second polynomial line L2 is determined according to the number of constraint conditions;

[0014] According to the following general polynomial expression:

[0015]

[0016] In the formula, F polynomial is the general expression of polynomial; f is the coefficient of expression variable; n is the number of variables;

[0017] Then the first polynomial profile L1 and the second polynomial profile L2 conform to the following expression:

[0018]

[0019] As a preferred solution, the volume of the membrane cavity enclosed by the membrane cavity line L obtained by the first polynomial line L1 and the second polynomial line L2 is solved by the following formula:

[0020]

[0021] According to the maximum limit volume V of the membrane cavity Lmax The maximum radius R of the membrane cavity line L max , the inclination angle Δθ of the inflection point of the profile and the maximum deflection H max Positive correlation, by adjusting the membrane cavity volume V L Equal to the set membrane cavity volume.

[0022] As a preferred solution, the position coordinates (x P ,y P ) and the inflection point angle Δθ of the profile, adjust the maximum radius R of the membrane cavity profile L max and the maximum deflection H max , the obtained membrane cavity line L is expressed by the following formula:

[0023] H L =F(R max ,H max ,x P ,y P ,Δθ)

[0024] According to the following formula, the set membrane cavity volume V enclosed by the membrane cavity line L under the design conditions is calculated according to the thermodynamic calculation method. L,Set :

[0025] V Cone =ζV L,Set

[0026] Where, ζ represents the design coefficient; V Cone Represents the volume of the cone Cone;

[0027] The maximum limit volume of the membrane cavity that can be enclosed by the membrane cavity line L is the bottom angle Δθ and the bottom radius R max The cone Cone is used to describe the membrane cavity volume V that can be enclosed by the membrane cavity line L. L Meet the following conditions:

[0028]

[0029] Where: H Cone Indicates the height of the cone Cone.

[0030] As a preferred solution, let H = H L The maximum and minimum surface stresses of the diaphragm of the diaphragm compressor when it is deformed close to the diaphragm cavity surface are calculated as follows:

[0031]

[0032] δ min =min{δ Pr ±δ Mr ,δ Pt ±δ Mt}

[0033] δ max =max{δ Pr ±δ Mr ,δ Pt ±δ Mt}

[0034] Wherein, H represents the equation of the membrane cavity profile with respect to radius r; E is the Young's modulus of the membrane material; μ is the Poisson's ratio of the membrane material; t is the membrane thickness; ∫ represents the mathematical integral operator; d represents the mathematical differential operator; δ Pr Indicates the radial normal stress of the diaphragm; δ Pt Indicates the circumferential normal stress of the diaphragm; δ Mr represents the radial shear stress of the diaphragm; δ Mr represents the circumferential shear stress of the diaphragm; δ min Indicates the minimum stress on the diaphragm surface; δ max Indicates the maximum stress on the diaphragm surface.

[0035] As a preferred solution, by solving the line equations of the first polynomial line L1 and the second polynomial line L2, the position coordinates (x P ,y P ) and the polynomial membrane cavity profile set Ψ of the profile inflection point inclination angle Δθ, the expression is as follows:

[0036]

[0037] The multi-objective optimization design of the polynomial membrane cavity profile set Ψ is performed according to the following formula:

[0038]

[0039] In the formula, H L,Best Indicates multi-objective optimization of membrane cavity profile; Find indicates optimization function; min indicates finding minimum value; δ indicates the surface stress of diaphragm compressor diaphragm applying corresponding polynomial membrane cavity profile; solve indicates solution function;

[0040] According to the strength condition of the fourth strength theory, when the diaphragm is deformed, the multi-objective optimization of the membrane cavity line H is applied. L,Best The equivalent pressure on the diaphragm surface of the diaphragm compressor is solved by the following expression:

[0041]

[0042] In the formula, represents the equivalent stress of the diaphragm; Q represents the shear stress of the diaphragm; [σ] represents the allowable stress of the diaphragm material;

[0043] According to the strength condition of the first strength theory, when the diaphragm is deformed, the stress in any direction meets the following formula:

[0044]

[0045] By making the diaphragm equivalent stress Substitute the calculated expression into the multi-objective optimization design expression, and then solve to obtain the multi-objective optimization membrane cavity line H that meets the multi-objective optimization design conditions. L,Best .

[0046] A compressor design method based on variable factor control polynomial membrane cavity profile includes the following steps:

[0047] Define the maximum radius R of the membrane cavity line L max , maximum deflection H max , the inclination angle Δθ of the line inflection point, given the position coordinates of the line generating point P (x P ,y P ) x P =λR max , where λ is the segmented proportional coefficient. Different segmented proportional coefficients λ are taken to calculate the polynomial membrane cavity profile set ψ;

[0048] In the polynomial membrane cavity line set ψ, the membrane cavity volume V enclosed by the membrane cavity line L under different segmented proportional coefficients λ is calculated L As the segment ratio coefficient λ increases, the membrane cavity volume V enclosed by the membrane cavity line L L Increase;

[0049] Calculate the maximum stress δ of the membrane surface corresponding to the membrane cavity line L under different segmented proportional coefficients λ max and the minimum value δ min ;

[0050] The equivalent stress of the membrane sheet corresponding to the membrane cavity line L under different segmented proportional coefficients λ is calculated As the segment proportional coefficient λ increases, the equivalent stress of the diaphragm at the center of the diaphragm Reduced, while the diaphragm equivalent stress at the edge of the diaphragm Increase;

[0051] Determine the segmented proportional coefficient λ that can obtain the target diaphragm stress distribution, and calculate the set diaphragm cavity volume V L,Set Design coefficient ζ and maximum equivalent stress corresponding to the segmented proportional coefficient λ and the membrane cavity volume V L ;

[0052] Fixed setting of membrane cavity volume V L,Set , change the inclination angle Δθ of the inflection point of the profile, and solve for the maximum radius R max and the maximum deflection H max , to obtain the same membrane cavity volume V L The membrane cavity line cluster, the maximum radius R max The larger the maximum deflection H max The smaller;

[0053] The diaphragm compressor diaphragm cavity profile that meets the allowable stress conditions is calculated.

[0054] As a preferred solution, the maximum stress δ corresponding to the membrane surface of the membrane cavity line L under different segmented proportional coefficients λ is calculated. max and the minimum value δ min In the steps, when λ=0.1, stress concentration occurs at the center of the membrane cavity, and when λ=0.9, stress concentration occurs at the edge of the membrane cavity. When λ=0.5, the stress distribution on the surface of the diaphragm is uniform.

[0055] As a preferred solution, in the step of calculating the diaphragm compressor diaphragm cavity profile that satisfies the allowable stress condition, the diaphragm cavity equivalent radius is defined as The equivalent stress of the diaphragm under different inflection angles Δθ is calculated. Get the equivalent stress of the diaphragm The inflection point inclination angle Δθ of the profile that meets the allowable stress condition, and the maximum radius R of the membrane cavity profile L max and the maximum deflection H max , thereby obtaining the set membrane cavity volume V L,Set The radius of the membrane cavity line under the verification is the maximum radius R of the membrane cavity line L. max and the maximum deflection H max And whether the inclination angle Δθ of the inflection point of the profile meets the strength requirements and the equivalent stress of the diaphragm Evenly distributed.

[0056] Compared with the prior art, the present invention has at least the following beneficial effects:

[0057] The diaphragm compressor structure proposed in the present invention has a diaphragm cavity designed and processed based on a variable factor controlled polynomial profile, wherein the variable factor controlled polynomial profile of the present invention is formed by continuously connecting a first polynomial profile L1 and a second polynomial profile L2, and has a position coordinate (x P ,y P ), the inclination angle Δθ of the inflection point of the profile, and the maximum radius R of the profile L of the membrane cavity max and the maximum deflection H max More adjustable design parameters are conducive to the membrane cavity profile design to meet the diverse market needs and product requirements, which can enrich the traditional single index profile design scheme and provide more optimization options. P ,y P ) and the inflection point angle Δθ of the profile, adjust the maximum radius R of the membrane cavity profile L max and the maximum deflection H max , the diaphragm compressor diaphragm cavity profile with set diaphragm cavity volume and satisfying allowable stress conditions is obtained, which has better design flexibility than the single parameter profile adjustment scheme of the traditional single exponential profile. The minimum design radius of the diaphragm cavity can be obtained through multi-objective parameter optimization of the profile diaphragm cavity (depending on the maximum radius R of the diaphragm cavity profile L). max ), the optimal profile generating point P and the appropriate profile inflection point inclination angle Δθ, providing reliable suggestions for the profile development of new models of diaphragm compressors. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific implementation methods or the description of the prior art. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0059] Figure 1 Schematic diagram of polynomial membrane cavity profile calculated under different segmented proportional coefficients λ in an embodiment of the present invention;

[0060] Figure 2 It is a schematic diagram of the membrane cavity volume enclosed by the polynomial membrane cavity profile calculated under different segmented proportional coefficients λ in an embodiment of the present invention;

[0061] Figure 3 is the maximum surface stress δ of the diaphragm calculated under different segmented proportional coefficients λ in the embodiment of the present invention max and the minimum surface stress of the diaphragm δ min Schematic diagram of the distribution along the radial direction;

[0062] Figure 4is the equivalent stress of the diaphragm calculated under different segmented proportional coefficients λ in the embodiment of the present invention Schematic diagram of the distribution along the radial direction;

[0063] Figure 5 Schematic diagram of membrane cavity profile clusters under segmented proportional coefficient λ=0.5 and different profile inflection point inclination angles Δθ in an embodiment of the present invention;

[0064] Figure 6 The equivalent stress of the diaphragm under the segmented proportional coefficient λ=0.5 and different inclination angles Δθ of the inflection point of the profile line in the embodiment of the present invention is Schematic diagram of the distribution along the radial direction. DETAILED DESCRIPTION

[0065] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0066] The embodiment of the present invention provides a compressor based on a variable factor controlled polynomial diaphragm cavity profile, which has a diaphragm cavity designed and processed based on the variable factor controlled polynomial profile, wherein the variable factor controlled polynomial profile is formed by continuously connecting a first polynomial profile L1 and a second polynomial profile L2, defining the connecting point of the first polynomial profile L1 and the second polynomial profile L2 as a profile generating point P, and taking the position and inclination characteristics of the profile generating point P as the generating features of the diaphragm cavity profile L, by controlling the position coordinates (x P ,y P ) and the inflection point angle Δθ of the profile, adjust the maximum radius R of the membrane cavity profile L max and the maximum deflection H max , obtain the diaphragm compressor diaphragm cavity profile that sets the diaphragm cavity volume and satisfies the allowable stress conditions.

[0067] Specifically, in the XOY coordinate system, any point in the first quadrant is taken as the membrane cavity line generation point P. The inclination angle of the line generation point P in the XOY coordinate system is the line inflection point inclination angle Δθ. According to the maximum radius R of the membrane cavity line L, max , maximum deflection H max , the starting position of the first polynomial line L1 is placed at the XOY coordinate origin O, and the starting position of the second polynomial line L2 is constrained by the line end position of the first polynomial line L1, then the initial conditions for generating the membrane cavity line L are set as follows:

[0068]

[0069] Wherein, R represents the radius of the corresponding membrane cavity line segment; x and y represent the coordinates of the corresponding membrane cavity line in the XOY coordinate system.

[0070] Considering that there are 5 equations defining the constraints of the first polynomial profile L1, there are 5 equations constraining the second polynomial profile L2, and the first polynomial profile L1 constrains the second polynomial profile L2, the expressions defining the first polynomial profile L1 and the second polynomial profile L2 are as follows:

[0071]

[0072] Wherein, a and b are line parameters of the first polynomial line L1 and the second polynomial line L2 respectively, and the number of line parameters of the first polynomial line L1 and the second polynomial line L2 is determined according to the number of constraint conditions.

[0073] Considering the general polynomial expression formula, it is defined as follows:

[0074]

[0075] In the formula, F polynomial is the general expression of a polynomial; f is the coefficient of the expression variable; n is the number of variables.

[0076] Therefore, the first polynomial profile L1 and the second polynomial profile L2 are defined to conform to the following expressions:

[0077]

[0078] Furthermore, the volume of the membrane cavity enclosed by the membrane cavity line L obtained by the first polynomial line L1 and the second polynomial line L2 is solved by the following formula:

[0079]

[0080] Furthermore, the maximum limit volume of the membrane cavity that can be enclosed by the polynomial membrane cavity profile that meets the above conditions is the bottom angle Δθ and the bottom radius R max The cone Cone is used to describe the membrane cavity volume V that can be enclosed by the membrane cavity line L. L Meet the following conditions:

[0081]

[0082] In the formula, H Cone Indicates the height of the cone Cone; V Cone Represents the volume of a cone.

[0083] Similarly, the above expression can be described as:

[0084]

[0085] It can be concluded that the maximum limit volume of the membrane cavity V Lmax The maximum radius R of the membrane cavity line L max , the inclination angle Δθ of the inflection point of the profile and the maximum deflection H max There is a positive correlation, by adjusting the membrane cavity volume V L Equal to the set membrane cavity volume.

[0086] Furthermore, through the above steps, the basic design parameters of the adjustable profile of the membrane cavity profile L can be determined, including the position coordinates (x P ,y P ) and the inflection point angle Δθ of the profile, adjust the maximum radius R of the membrane cavity profile L max and the maximum deflection H max , the obtained membrane cavity line L is expressed by the following formula:

[0087] H L =F(R max ,H max ,x P ,y P ,Δθ)

[0088] Optionally, in the process of designing the membrane cavity profile, the set membrane cavity volume V enclosed by the membrane cavity profile L can be determined based on the thermodynamic calculation design conditions. L,Set In order to make the overall slope of the membrane cavity profile L change smoothly, define:

[0089] V Cone =ζV L,Set

[0090] Wherein: ζ-design coefficient, preferably 2 to 6.

[0091] Let H = H L The theoretical calculation formula for the maximum and minimum surface stress of the diaphragm compressor diaphragm using the diaphragm cavity profile of the embodiment of the present invention when deformed close to the diaphragm cavity profile is as follows:

[0092]

[0093]

[0094] δ min =min{δ Pr ±δ Mr ,δ Pt ±δ Mt}

[0095] δ max =max{δ Pr ±δ Mr ,δ Pt ±δMt}

[0096] Wherein, H represents the equation of the membrane cavity profile with respect to radius r; E is the Young's modulus of the membrane material; μ is the Poisson's ratio of the membrane material; t is the membrane thickness; ∫ represents the mathematical integral operator; d represents the mathematical differential operator; δ Pr Indicates the radial normal stress of the diaphragm; δ Pt Indicates the circumferential normal stress of the diaphragm; δ Mr represents the radial shear stress of the diaphragm; δ Mr represents the circumferential shear stress of the diaphragm; δ min Indicates the minimum stress on the diaphragm surface; δ max Indicates the maximum stress on the diaphragm surface.

[0097] Furthermore, the line equations of the first polynomial line L1 and the second polynomial line L2 can be specifically solved, thereby obtaining a polynomial membrane cavity line set Ψ that can control the connection point position and inclination, which is defined as the following formula:

[0098]

[0099] The following multi-objective optimization design is performed on the above polynomial membrane cavity profile set Ψ:

[0100]

[0101] In the formula, H L,Best Indicates multi-objective optimization of membrane cavity profile; Find indicates optimization function; min indicates finding minimum value; δ indicates the surface stress of diaphragm compressor diaphragm applying corresponding polynomial membrane cavity profile; solve indicates solution function;

[0102] According to the strength condition of the fourth strength theory, when the diaphragm is deformed, the multi-objective optimization of the membrane cavity line H is applied. L,Best The equivalent pressure on the diaphragm surface of the diaphragm compressor is solved by the following expression:

[0103]

[0104] In the formula, Indicates the equivalent stress of the diaphragm; δ Pr Indicates the radial stress of the diaphragm; δ Mr represents the circumferential stress of the diaphragm; Q represents the shear stress of the diaphragm; [σ] represents the allowable stress of the diaphragm material.

[0105] According to the strength condition of the first strength theory, when the diaphragm is deformed, the stress in any direction should be less than the allowable stress of the diaphragm material, which can be described as:

[0106]

[0107] Surface equivalent stress Substituting the calculation formula into δ in the above multi-objective optimization design expression, the optimized polynomial diaphragm cavity profile that meets the above design conditions can be solved, and then the diaphragm cavity of the diaphragm compressor can be designed and processed.

[0108] Another embodiment of the present invention further provides a compressor design method based on variable factor control polynomial membrane cavity profile:

[0109] Define the maximum radius R of the membrane cavity line L max =360mm, maximum deflection H max =9.4mm, membrane cavity line P point inclination Given Given x P =λR max , where λ is the segmented proportional coefficient. Taking different segmented proportional coefficients λ = 0.1, 0.3, 0.5, 0.7, and 0.9, we calculated the polynomial membrane cavity line cluster as follows: Figure 1 shown.

[0110] Furthermore, the membrane cavity volume V enclosed by the membrane cavity line L under different segmented proportional coefficients λ is calculated. L ,like Figure 2 As shown in the figure, with the increase of the segment ratio coefficient λ, the membrane cavity volume V enclosed by the membrane cavity line L L Increase.

[0111] Furthermore, the maximum stress δ of the membrane surface corresponding to the membrane cavity line L under different segmented proportional coefficients λ is calculated. max and the minimum value δ min ,like Figure 3 As shown in the figure, when λ = 0.1, stress concentration occurs at the center of the membrane cavity, and the stress on the membrane surface is relatively large.

[0112] When λ=0.9, stress concentration occurs at the edge of the membrane cavity and the stress on the diaphragm surface is relatively large. When λ=0.5, the stress distribution on the diaphragm surface is the most uniform.

[0113] Furthermore, according to the fourth strength theory, the equivalent stress of the membrane corresponding to the membrane cavity line L under different segmented proportional coefficients λ is calculated: like Figure 4 As shown in the figure, with the increase of the segmented proportional coefficient λ, the equivalent stress of the diaphragm at the center of the diaphragm Reduced, while the diaphragm equivalent stress at the edge of the diaphragm Increase.

[0114] Preferably, according to the above calculation results, when the segmented proportional coefficient λ is 0.5, a better diaphragm stress distribution can be obtained, which is beneficial to improving the life of the diaphragm. The set diaphragm cavity volume V is calculated to be L,SetThe design coefficient ζ corresponding to the segment ratio coefficient λ = 0.5 is 2.23, and the maximum equivalent stress Membrane cavity volume V L =1120000mm 3 .

[0115] Furthermore, the above-mentioned set membrane cavity volume V is fixed L,Set =1120000mm 3 , change the inclination angle of the inflection point of the profile The maximum radius R is obtained by solving max and the maximum deflection H max , and then obtain the same membrane cavity volume V L The membrane cavity line clusters, such as Figure 5 As shown, the maximum radius of the membrane cavity R max The larger the maximum deflection H max The smaller.

[0116] Define the equivalent radius of the membrane cavity The equivalent stress of the membrane cavity under different inflection angles Δθ is calculated. ,like Figure 6 As shown, the equivalent stress Within the stress range, the maximum inclination angle of the membrane cavity line is approximately equal to The maximum radius of the membrane cavity under this membrane cavity inclination angle is R max =338mm, the maximum deflection of the membrane cavity is H max =10.7mm, thus obtaining the set membrane cavity volume V L,Set The radius of the membrane cavity profile should not be less than 338 mm, which verifies the above conditions. max =360mm, H max =9.4mm and The strength requirements are met and the equivalent stress is evenly distributed.

[0117] The embodiment of the present invention proposes a compressor and a design method based on a polynomial diaphragm cavity profile controlled by a variable factor. The diaphragm cavity profile is continuously connected by two sections of polynomial profiles controlled by different variable factors, including a first polynomial profile L1 and a second polynomial profile L2, which can meet the design conditions of the diaphragm compressor diaphragm cavity profile and have a maximum radius R of the diaphragm cavity profile. max , maximum deflection H max 、Position coordinates of the line generation point P (x P ,y P ) and the inflection point angle Δθ of the profile design parameters. More adjustable design parameters are conducive to the membrane cavity profile design to meet the diverse market needs and product requirements, and can enrich the traditional single exponential profile design scheme and provide more optimization options. The present invention controls the coordinates (xP ,y P ) and the inflection angle Δθ of the profile, adjust the maximum radius R of the membrane cavity profile max and the maximum deflection H max To obtain the set membrane cavity profile volume V L,Set The diaphragm cavity profile with the conditions of pressure relief and allowable stress has better design flexibility than the single parameter profile adjustment scheme of the traditional single exponential profile. The minimum design radius of the diaphragm cavity, the optimal profile generation point P and the suitable profile inflection point inclination Δθ can be obtained through multi-objective parameter optimization of the profile membrane cavity, providing reliable suggestions for the profile development of new diaphragm compressor models.

[0118] Although the present application is described above with reference to specific embodiments, it should be understood by those skilled in the art that many modifications may be made to the configurations and details disclosed in the present application within the principles and scope disclosed in the present application. The scope of protection of the present application is determined by the attached claims, and the claims are intended to cover all modifications included in the equivalent literal meaning or scope of the technical features in the claims.

Claims

1. A compressor based on variable factor control polynomial membrane cavity profile, characterized in that: The invention relates to a membrane cavity designed and processed based on a variable factor controlled polynomial profile, wherein the variable factor controlled polynomial profile is formed by continuously connecting a first polynomial profile L1 and a second polynomial profile L2, defining the connecting point of the first polynomial profile L1 and the second polynomial profile L2 as a profile generating point P, taking the position and inclination characteristics of the profile generating point P as the generating features of the membrane cavity profile L, and controlling the position coordinates (x P ,y P ) and the inflection point angle Δθ of the profile, adjust the maximum radius R of the membrane cavity profile L max and the maximum deflection H max , obtain the diaphragm compressor diaphragm cavity profile that sets the diaphragm cavity volume and satisfies the allowable stress conditions.

2. The compressor based on variable factor control polynomial diaphragm cavity profile according to claim 1, characterized in that: In the XOY coordinate system, any point in the first quadrant is taken as the profile generating point P. The inclination angle of the profile generating point P in the XOY coordinate system is the profile inflection point inclination angle Δθ. According to the maximum radius R of the membrane cavity profile L, max , maximum deflection H max , the starting position of the first polynomial line L1 is placed at the XOY coordinate origin O, and the starting position of the second polynomial line L2 is constrained by the line end position of the first polynomial line L1, then the initial conditions for generating the membrane cavity line L are set as follows: Wherein, R represents the radius of the corresponding membrane cavity line segment; x and y represent the coordinates of the corresponding membrane cavity line in the XOY coordinate system.

3. The compressor based on variable factor control polynomial diaphragm cavity profile according to claim 2, characterized in that: The expressions defining the first polynomial profile L1 and the second polynomial profile L2 are as follows: Wherein, a and b are line parameters of the first polynomial line L1 and the second polynomial line L2 respectively, and the number of line parameters of the first polynomial line L1 and the second polynomial line L2 is determined according to the number of constraint conditions; According to the following general polynomial expression: In the formula, F polynomial is the general expression of polynomial; f is the coefficient of expression variable; n is the number of variables; Then the first polynomial profile L1 and the second polynomial profile L2 conform to the following expression:

4. The compressor according to claim 3, characterized in that: The volume of the membrane cavity enclosed by the membrane cavity line L obtained by the first polynomial line L1 and the second polynomial line L2 is solved by the following formula: According to the maximum limit volume V of the membrane cavity Lmax The maximum radius R of the membrane cavity line L max , the inclination angle Δθ of the inflection point of the profile and the maximum deflection H max Positive correlation, by adjusting the membrane cavity volume V L Equal to the set membrane cavity volume.

5. The compressor based on variable factor control polynomial diaphragm cavity profile according to claim 4, characterized in that: By controlling the position coordinates (x P ,y P ) and the inflection point angle Δθ of the profile, adjust the maximum radius R of the membrane cavity profile L max and the maximum deflection H max , the obtained membrane cavity line L is expressed by the following formula: H L =F(R max ,H max ,x P ,y P ,Δθ) According to the following formula, the set membrane cavity volume V enclosed by the membrane cavity line L under the design conditions is calculated according to the thermodynamic calculation method. L,Set : V Cone =ζV L,Set Where, ζ represents the design coefficient; V Cone Represents the volume of the cone Cone; The maximum limit volume of the membrane cavity that can be enclosed by the membrane cavity line L is the bottom angle Δθ and the bottom radius R max The cone Cone is used to describe the membrane cavity volume V that can be enclosed by the membrane cavity line L. L Meet the following conditions: Where: H Cone Indicates the height of the cone Cone.

6. The compressor based on variable factor control polynomial diaphragm cavity profile according to claim 5, characterized in that: Let H = H L The maximum and minimum surface stresses of the diaphragm of the diaphragm compressor when it is deformed close to the diaphragm cavity surface are calculated as follows: d min =min{δ Pr ±δ Mr ,d Pt ±δ Mt } d max =max{δ Pr ±δ Mr ,d Pt ±δ Mt } Wherein, H represents the equation of the membrane cavity profile with respect to radius r; E is the Young's modulus of the membrane material; μ is the Poisson's ratio of the membrane material; t is the membrane thickness; ∫ represents the mathematical integral operator; d represents the mathematical differential operator; δ Pr Indicates the radial normal stress of the diaphragm; δ Pt Indicates the circumferential normal stress of the diaphragm; δ Mr represents the radial shear stress of the diaphragm; δ Mr represents the circumferential shear stress of the diaphragm; δ min Indicates the minimum stress on the diaphragm surface; δ max Indicates the maximum stress on the diaphragm surface.

7. The compressor based on variable factor control polynomial diaphragm cavity profile according to claim 6, characterized in that: By solving the line equations of the first polynomial line L1 and the second polynomial line L2, the position coordinates (x P ,y P ) and the polynomial membrane cavity profile set Ψ of the profile inflection point inclination angle Δθ, the expression is as follows: The multi-objective optimization design of the polynomial membrane cavity profile set Ψ is performed according to the following formula: In the formula, H L,Best Indicates multi-objective optimization of membrane cavity profile; Find indicates optimization function; min indicates finding the minimum value; δ represents the surface stress of the diaphragm of the diaphragm compressor using the corresponding polynomial diaphragm cavity profile; solve represents the solution function; According to the strength condition of the fourth strength theory, when the diaphragm is deformed, the multi-objective optimization of the membrane cavity line H is applied. L,Best The equivalent pressure on the diaphragm surface of the diaphragm compressor is solved by the following expression: In the formula, represents the equivalent stress of the diaphragm; Q represents the shear stress of the diaphragm; [σ] represents the allowable stress of the diaphragm material; According to the strength condition of the first strength theory, when the diaphragm is deformed, the stress in any direction meets the following formula: By making the diaphragm equivalent stress Substitute the calculated expression into the multi-objective optimization design expression, and then solve to obtain the multi-objective optimization membrane cavity line H that meets the multi-objective optimization design conditions. L,Best .

8. A compressor design method based on variable factor control polynomial membrane cavity profile, characterized in that: include: Define the maximum radius R of the membrane cavity line L max , maximum deflection H max , the inclination angle Δθ of the line inflection point, given the position coordinates of the line generating point P (x P ,y P ) x P =λR max , where λ is the segmented proportional coefficient. Different segmented proportional coefficients λ are taken to calculate the polynomial membrane cavity profile set Ψ; In the polynomial membrane cavity line set Ψ, the membrane cavity volume V enclosed by the membrane cavity line L under different segmented proportional coefficients λ is calculated L As the segment ratio coefficient λ increases, the membrane cavity volume V enclosed by the membrane cavity line L L Increase; Calculate the maximum stress δ of the membrane surface corresponding to the membrane cavity line L under different segmented proportional coefficients λ max and the minimum value δ min ; The equivalent stress of the membrane sheet corresponding to the membrane cavity line L under different segmented proportional coefficients λ is calculated As the segment proportional coefficient λ increases, the equivalent stress of the diaphragm at the center of the diaphragm Reduced, while the diaphragm equivalent stress at the edge of the diaphragm Increase; Determine the segmented proportional coefficient λ that can obtain the target diaphragm stress distribution, and calculate the set diaphragm cavity volume V L,Set Design coefficient ζ and maximum equivalent stress corresponding to the segmented proportional coefficient λ and the membrane cavity volume V L ; Fixed setting of membrane cavity volume V L,Set , change the inflection point angle Δθ of the profile, and solve for the maximum radius R of the membrane cavity max and the maximum deflection H max , to obtain the same membrane cavity volume V L The membrane cavity line cluster, the maximum radius R max The larger the maximum deflection H max The smaller; The diaphragm compressor diaphragm cavity profile that meets the allowable stress conditions is calculated.

9. The compressor design method based on variable factor control polynomial diaphragm cavity profile according to claim 8, characterized in that: The maximum stress δ of the membrane surface corresponding to the membrane cavity line L under different segmented proportional coefficients λ is calculated. max and the minimum value δ min In the steps, when λ=0.1, stress concentration occurs at the center of the membrane cavity, and when λ=0.9, stress concentration occurs at the edge of the membrane cavity. When λ=0.5, the stress distribution on the surface of the diaphragm is uniform.

10. The compressor design method based on variable factor control polynomial diaphragm cavity profile according to claim 8, characterized in that: In the step of calculating the diaphragm compressor diaphragm cavity profile that satisfies the allowable stress condition, the diaphragm cavity equivalent radius is defined The equivalent stress of the diaphragm under different inflection angles Δθ is calculated. Get the equivalent stress of the diaphragm The inflection point inclination angle Δθ of the profile that meets the allowable stress condition, and the maximum radius R of the membrane cavity profile L max and the maximum deflection H max , thereby obtaining the set membrane cavity volume V L,Set The radius of the membrane cavity line under the verification is the maximum radius R of the membrane cavity line L. max and the maximum deflection H max And whether the inclination angle Δθ of the inflection point of the profile meets the strength requirements and the equivalent stress of the diaphragm Evenly distributed.

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