A diaphragm compressor based on double-cutting-arc membrane cavity type line and a design method thereof

Abstract

A diaphragm compressor based on a double-cut circular arc membrane cavity profile and a design method thereof, the diaphragm compressor has a membrane cavity designed and processed based on a double-cut circular arc profile, the double-cut circular arc profile is composed of a continuous first circular arc profile HA and a second circular arc profile HB, the first circular arc profile HA and the second circular arc profile HB are connected and tangent at the connection. By adjusting the design parameters of the first circular arc profile HA, the stress distribution of the diaphragm compressor can be adjusted, and by profile parameter design based on theoretical mechanics analysis and membrane cavity surface optimization, smaller stress can be obtained than the traditional single exponential profile under the same membrane cavity volume design parameters, which is beneficial to improve the service life of the diaphragm compressor and improve the reliability of the whole machine. The membrane cavity designed and processed based on the double-cut circular arc profile has more profile design parameters, increases the profile design flexibility of the diaphragm compressor, and can overcome the problems of insufficient optimization parameters and limited optimization range of the traditional single exponential profile design.

Description

Technical Field

[0001] This invention belongs to the field of diaphragm compressor technology, specifically relating to a diaphragm compressor based on a double-tangential circular arc membrane cavity profile and its design method. Background Technology

[0002] A diaphragm compressor is a positive displacement compressor that separates the oil and gas sides using a diaphragm. Its working principle involves an electric motor driving a crankshaft and connecting rod, which in turn drives a piston in reciprocating motion to pressurize and depressurize high-pressure oil. This high-pressure oil then pushes the diaphragm to compress and discharge the gas. Due to its excellent sealing and high pressure ratio, diaphragm compressors are widely used in the hydrogen energy industry, with hydrogen refueling stations being a crucial application scenario. However, diaphragm lifespan, volumetric efficiency, and diaphragm head strength are critical and challenging issues in the development of diaphragm compressors. The diaphragm is a key component for the stable operation of a diaphragm compressor, and its performance directly affects the compressor's reliability. Diaphragm damage primarily manifests as collapse, torsional deformation, wear cracks, and mechanical fatigue. Damage to the diaphragm leads to the destruction of its mechanical properties, and in severe cases, can result in significant economic losses.

[0003] Currently, the membrane cavity profile of diaphragm compressors widely used in China is the single-index, small-deflection membrane cavity profile. Through long-term practice and verification, it has proven to have good reliability and a solid practical foundation. However, in the development and design of new diaphragm compressor models, the traditional single-index membrane cavity profile, which is adjusted by three profile variables—mold radius, single index, and maximum deflection—has a limited optimization range and cannot meet the urgent needs of diaphragm compressor technology development and the research and development of new high-pressure, high-speed models. Multi-parameter membrane cavity profile optimization design is an effective way to improve the reliability and reduce the cost of diaphragm compressors. Summary of the Invention

[0004] The purpose of this invention is to address the problems in the prior art by providing a diaphragm compressor and its design method based on a double-tangential circular arc diaphragm cavity profile, thereby increasing the flexibility of the diaphragm compressor profile design and improving diaphragm life and overall machine reliability.

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

[0006] In a first aspect, a diaphragm compressor based on a double-tangential circular arc membrane cavity profile is provided, having a membrane cavity designed and manufactured based on the double-tangential circular arc profile, wherein the double-tangential circular arc profile is composed of a continuous first circular arc profile HA and a second circular arc profile HB, wherein the first circular arc profile HA and the second circular arc profile HB are connected and tangent at the connection point.

[0007] As a preferred embodiment, the double-tangent circular arc profile conforms to the following profile equation:

[0008]

[0009] In the formula, H(r) is the equation of the double-tangent circular arc profile; HA(r) is the equation of the first circular arc profile; HB(r) is the equation of the second circular arc profile; r is the radius of the membrane cavity; x p R is the ratio of the cavity radius corresponding to the first circular arc to the maximum cavity radius; max This represents the maximum membrane cavity radius.

[0010] As a preferred embodiment, the mathematical expression for the equation HA(r) of the first circular arc is as follows:

[0011]

[0012] In the formula, XO first YO is the x-coordinate of the center of the first circular arc HA; first R is the ordinate of the center of the first circular arc HA; first Let HA be the radius of the first circular arc.

[0013] As a preferred embodiment, the design of the first arc-shaped line HA satisfies the following conditional expression:

[0014]

[0015] In the formula, H max It represents the maximum value of the ordinate of the first circular arc HA.

[0016] As a preferred option, the specific radius ρ is defined by the following expression:

[0017]

[0018] The mathematical expression for the equation HA of the first circular arc is as follows:

[0019]

[0020] The mathematical expression for the second circular arc line equation HB is as follows:

[0021]

[0022] In the formula, XO second YO is the x-coordinate of the center of the second circular arc HB. second R is the ordinate of the center of the second circular arc HB; second Let HB be the radius of the second circular arc.

[0023] As a preferred embodiment, the design of the second circular arc line equation HB satisfies the following conditional expression:

[0024]

[0025] As a preferred embodiment, the first arc-shaped line HA and the second arc-shaped line HB are connected and tangent at the connection point, satisfying the following expression:

[0026]

[0027] As a preferred embodiment, the half-cavity volume VH of the membrane cavity designed and fabricated based on a double-tangent circular arc profile is calculated using the following formula:

[0028]

[0029] As a preferred embodiment, the maximum and minimum surface stress of the diaphragm compressor diaphragm when it deforms close to the membrane cavity surface is calculated using the following formula:

[0030]

[0031] σ min =min{σ Pr ±σ Mr ,σ Pt ±σ Mt}

[0032] σ max =max{σ Pr ±σ Mr ,σ Pt ±σ Mt}

[0033] In the formula, E is the Young's modulus of the diaphragm material; μ is the Poisson's ratio of the diaphragm material; t is the diaphragm thickness; ∫ is the mathematical integral operator; d is the mathematical differential operator; σ Pr The radial normal stress of the diaphragm; σ Pt σ is the circumferential normal stress of the diaphragm; Mr For the radial shear stress of the diaphragm; σ Mr For the circumferential shear stress of the diaphragm; σ min The minimum stress on the diaphragm surface; σ max This represents the maximum stress on the diaphragm surface.

[0034] Secondly, a design method for a diaphragm compressor based on a double-tangential circular arc membrane cavity profile is provided, comprising the following steps:

[0035] The stress distribution of the diaphragm compressor can be adjusted by adjusting the design parameters of the first arc-shaped line HA.

[0036] By adjusting the stress distribution of the diaphragm compressor, the stress concentration of the oil distribution plate and the through holes on the cylinder head of the diaphragm compressor is prevented from coinciding with the location of the maximum stress on the diaphragm cavity profile.

[0037] Compared with the prior art, the present invention has at least the following beneficial effects:

[0038] The membrane cavity of the diaphragm compressor of this invention is designed and manufactured based on a double-tangential circular arc profile. This profile consists of a continuous first circular arc profile HA and a second circular arc profile HB, which connect and are tangent at the junction. By adjusting the design parameters of the first circular arc profile HA, the stress distribution of the diaphragm compressor can be adjusted. Through profile parameter design based on theoretical mechanical analysis and membrane cavity surface optimization, lower stress can be achieved compared to the traditional single-exponential profile under the same membrane cavity volume design parameters. This is beneficial for improving the diaphragm life of the diaphragm compressor and enhancing the overall reliability of the machine. The membrane cavity designed and manufactured based on the double-tangential circular arc profile of this invention has more profile design parameters than the traditional single-exponential profile, increasing the flexibility of the diaphragm compressor profile design. Reasonable profile optimization design helps reduce the overall manufacturing cost of the diaphragm compressor and improves the product's market competitiveness. In practical diaphragm compressor cavity design, by adjusting the stress distribution of the diaphragm compressor, the stress concentration of the oil distribution plate and the through holes on the cylinder head is prevented from coinciding with the location of the maximum stress on the cavity profile. This provides guidance for the research and design of diaphragm compressors using a double-tangential circular arc cavity profile. This invention, based on a double-tangential circular arc cavity profile, overcomes the problems of insufficient optimization parameters and limited optimization range in traditional single-exponential profile design, adapting to diverse market demands, optimizing diaphragm compressor reliability, and increasing diaphragm life. Attached Figure Description

[0039] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art are briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 The radius R of the first arc-shaped line HA in this embodiment of the invention first =6000mm double-tangential circular arc membrane cavity profile diagram;

[0041] Figure 2 The radius R of the traditional single-index membrane cavity profile and the first circular arc profile HA in embodiments of the present invention with indices Z = 3, 5, and 7 is given. first =Schematic diagram of double-tangential circular arc membrane cavity profiles for 3000mm, 5000mm, 6000mm, and 7000mm;

[0042] Figure 3The radius R of the traditional single-index membrane cavity profile and the first circular arc profile HA in embodiments of the present invention with indices Z = 3, 5, and 7 is given. first =Schematic diagram of the volume of the membrane cavity half-cavity enclosed by the double-tangent circular arc membrane cavity profiles of 3000mm, 5000mm, 6000mm, and 7000mm;

[0043] Figure 4 This is a schematic diagram of the maximum and minimum stress on the diaphragm surface of a diaphragm compressor with a traditional single-index diaphragm cavity profile (Z = 3, 5, 7) according to an embodiment of the present invention.

[0044] Figure 5 In this embodiment of the invention, the radius R of the first circular arc HA is applied. first Schematic diagram of the maximum and minimum stress on the diaphragm surface of a diaphragm compressor with double-tangential circular arc diaphragm cavity profiles of 3000mm, 5000mm, 6000mm, and 7000mm. Detailed Implementation

[0045] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] See Figure 1 This invention proposes a diaphragm compressor based on a double-tangential circular arc membrane cavity profile, which has a membrane cavity designed and manufactured based on a double-tangential circular arc profile H. The double-tangential circular arc profile H is composed of a continuous first circular arc profile HA and a second circular arc profile HB. The first circular arc profile HA and the second circular arc profile HB are connected and tangent at the connection point.

[0047] The double-tangent circular arc profile H conforms to the following profile equation:

[0048]

[0049] In the formula, H(r) is the equation of the double-tangent circular arc profile; HA(r) is the equation of the first circular arc profile; HB(r) is the equation of the second circular arc profile; r is the radius of the membrane cavity; x p R is the ratio of the cavity radius corresponding to the first arc shape to the maximum cavity radius; max This represents the maximum membrane cavity radius.

[0050] Furthermore, the mathematical expression for the equation HA(r) of the first circular arc is as follows:

[0051]

[0052] In the formula, XO firstYO is the x-coordinate of the center of the first circular arc HA; first R is the ordinate of the center of the first circular arc HA; first Let HA be the radius of the first circular arc.

[0053] The design of the first arc-shaped line HA satisfies the following conditional expression:

[0054]

[0055] In the formula, H max It represents the maximum value of the ordinate of the first circular arc HA.

[0056] Furthermore, the specific radius ρ is defined by the following expression:

[0057]

[0058] The mathematical expression for the equation HA of the first circular arc is as follows:

[0059]

[0060] Similarly, the mathematical expression for the second circular arc line equation HB is as follows:

[0061]

[0062] In the formula, XO second YO is the x-coordinate of the center of the second circular arc HB. second R is the ordinate of the center of the second circular arc HB; second Let HB be the radius of the second circular arc.

[0063] The design of the second circular arc profile equation HB satisfies the following condition expression:

[0064]

[0065] The first circular arc line HA and the second circular arc line HB are connected and tangent at the connection point, satisfying the following expression:

[0066]

[0067] In one possible implementation, the half-cavity volume VH of the membrane cavity, which is designed and fabricated based on a double-tangent circular arc profile, is calculated using the following formula:

[0068]

[0069] Furthermore, the maximum and minimum surface stress of the diaphragm compressor diaphragm when deformed to closely fit the membrane cavity profile described in this invention are calculated using the following formula:

[0070]

[0071] σ min =min{σ Pr ±σ Mr ,σ Pt ±σ Mt}

[0072] σ max =max{σ Pr ±σ Mr ,σ Pt ±σ Mt}

[0073] In the formula, E is the Young's modulus of the diaphragm material; μ is the Poisson's ratio of the diaphragm material; t is the diaphragm thickness; ∫ is the mathematical integral operator; d is the mathematical differential operator; σ Pr The radial normal stress of the diaphragm; σ Pt σ is the circumferential normal stress of the diaphragm; Mr For the radial shear stress of the diaphragm; σ Mr For the circumferential shear stress of the diaphragm; σ min The minimum stress on the diaphragm surface; σ max This represents the maximum stress on the diaphragm surface.

[0074] Another embodiment of the present invention also proposes a design method for a diaphragm compressor based on a double-tangential circular arc membrane cavity profile, which mainly includes the following steps:

[0075] The stress distribution of the diaphragm compressor can be adjusted by adjusting the design parameters of the first arc-shaped line HA.

[0076] By adjusting the stress distribution of the diaphragm compressor, the stress concentration of the oil distribution plate and the through holes on the cylinder head of the diaphragm compressor is prevented from coinciding with the location of the maximum stress on the diaphragm cavity profile.

[0077] According to the description of the above embodiments of the present invention, stress concentration refers to the phenomenon that when an object is subjected to external force, the local stress increases significantly due to a sudden change in its shape, size or structure.

[0078] In diaphragm compressors, if the stress concentration points of the oil distribution plate and cylinder head through holes coincide with the location of maximum stress on the diaphragm cavity profile, the stress level in that area will further increase, thereby increasing the risk of structural failure. Areas of stress concentration are more prone to structural damage, such as cracks and fractures. Therefore, avoiding the overlap of stress concentration points with the location of maximum stress can ensure the overall structural strength of the diaphragm compressor and prevent structural failure due to excessive local stress.

[0079] Meanwhile, prolonged operation under high-stress environments accelerates material fatigue and aging, thereby reducing equipment durability. By optimizing structural design and avoiding stress concentrations coinciding with areas of maximum stress, the service life of diaphragm compressors can be extended.

[0080] In addition, stress concentration can cause vibration and noise problems in diaphragm compressors during operation, affecting the normal operation and performance of the equipment. Therefore, a reasonable structural design to avoid stress concentration is of great significance for improving the overall performance of the equipment. Stress concentration can also affect the stability of the diaphragm compressor, making it more susceptible to interference and influence from external factors during operation. By optimizing the structural design and improving the stability of the equipment, it is possible to ensure that the diaphragm compressor can operate stably under various operating conditions.

[0081] In practical operation and maintenance, avoiding the overlap of stress concentration points with areas of maximum stress can reduce the probability of equipment failure during operation, thereby reducing the maintenance difficulty and workload for operators. Since stress concentration is one of the main causes of equipment failure and damage, optimizing the structural design to avoid this problem can significantly reduce equipment maintenance costs and downtime.

[0082] Further comparative verification shows that the traditional single-exponential membrane cavity profile consists of a complete and continuous profile. The equation for the single-exponential membrane cavity profile used in a typical diaphragm compressor can be described by the following formula:

[0083]

[0084] Where: HD - single exponential membrane cavity profile equation; ρ - specific radius; H max - Maximum deflection of the single-index membrane cavity profile; Z - Single-index membrane cavity profile index.

[0085] Please see Figure 2 Compare the membrane cavity profiles with different single-index membrane cavity profile indices Z=3, 5, and 7, and the radius R of the first circular arc profile HA. first Using double-tangential circular arc membrane cavity profiles of 3000mm, 5000mm, 6000mm, and 7000mm, the half-cavity volume VH enclosed by different membrane cavity profiles was calculated. Please refer to [link / reference]. Figure 3 Take the maximum radius R of the membrane cavity max =360mm, maximum deflection of membrane cavity H max =8mm, the half-cavity volume VH of the single-exponential membrane cavity profile increases with the increase of the exponent Z, while the half-cavity volume VH of the double-tangential circular arc membrane cavity profile increases with the radius R of the first circular arc profile. first The increase is due to the increase of Z=7, while the single exponential membrane cavity profile and R first The membrane cavity half-cavity volume is the same for double-tangential circular arc membrane cavity profiles with a diameter of 6000mm.

[0086] like Figures 4 to 5 As shown, the maximum surface stress σ of the diaphragm compressor with different membrane cavity profiles, obtained through theoretical mechanical analysis and calculation, is... max and minimum value σ min With the change of specific radius. By comparison, it can be seen that under the same membrane cavity radius conditions, the maximum stress of the double-circular arc membrane cavity profile is less than the yield strength of 210 MPa of general membrane materials, while the maximum stress σ of the traditional single-exponential membrane cavity profile is less. max The pressure is close to 250 MPa, indicating that under these design conditions, the double-circular-arc membrane cavity profile has a smaller maximum stress σ. max This is beneficial for improving the stress on the diaphragm.

[0087] This invention relates to a diaphragm compressor based on a double-tangential circular arc membrane cavity profile. By improving the membrane cavity surface and design parameters, it can achieve lower stress compared to the traditional single-index profile under the same membrane cavity volume design parameters. This is beneficial for improving the diaphragm life of the diaphragm compressor and enhancing the overall reliability of the machine. Furthermore, through reasonable profile optimization design, it is also beneficial for reducing the overall manufacturing cost of the diaphragm compressor and improving the product's market competitiveness.

[0088] Although this application has been described above with reference to specific embodiments, those skilled in the art will understand that many modifications can be made to the configurations and details disclosed in this application within the principles and scope of the disclosure. The scope of protection of this application is determined by the appended claims, and the claims are intended to cover all modifications included in the literal meaning or scope of equivalents of the technical features in the claims.

Claims

1. A design method for a diaphragm compressor based on a double-tangential circular arc membrane cavity profile, characterized in that, The diaphragm compressor has a membrane cavity designed and manufactured based on a double-tangent circular arc profile. The double-tangent circular arc profile is composed of a continuous first circular arc profile HA and a second circular arc profile HB. The first circular arc profile HA and the second circular arc profile HB are connected and tangent at the connection point. The stress distribution of the diaphragm compressor can be adjusted by adjusting the design parameters of the first arc-shaped line HA. By adjusting the stress distribution of the diaphragm compressor, the stress concentration of the oil distribution plate and the through holes on the cylinder head of the diaphragm compressor is prevented from coinciding with the location of the maximum stress on the diaphragm cavity profile. The aforementioned double-tangent circular arc profile conforms to the following profile equation: In the formula, The equation for a double-tangent circular arc is given. The equation for the first circular arc shape; The equation for the second circular arc shape; The radius of the membrane cavity; The ratio of the cavity radius corresponding to the first circular arc to the maximum cavity radius; The maximum cavity radius; The first circular arc line equation The mathematical expression is as follows: In the formula, Let x be the x-coordinate of the center of the first circular arc HA; Let be the ordinate of the center of the first circular arc HA; Let HA be the radius of the first circular arc. The design of the first arc-shaped line HA satisfies the following conditional expression: In the formula, The maximum value of the ordinate of the first circular arc HA; The second circular arc line equation The design satisfies the following conditional expression: The first circular arc line HA and the second circular arc line HB are connected and tangent at the connection point, satisfying the following expression: 。 2. The diaphragm compressor design method based on a double-tangential circular arc membrane cavity profile according to claim 1, characterized in that, The ratio of radii is defined by the following expression. : Then the equation of the first circular arc shape The mathematical expression is as follows: The second circular arc line equation The mathematical expression is as follows: In the formula, Let x be the x-coordinate of the center of the second circular arc HB; Let be the ordinate of the center of the second circular arc HB; Let HB be the radius of the second circular arc.

3. The diaphragm compressor design method based on a double-tangential circular arc membrane cavity profile according to claim 1, characterized in that, The volume of the membrane cavity, designed and fabricated based on a double-tangent circular arc profile, is calculated using the following formula. : 。 4. The diaphragm compressor design method based on a double-tangential circular arc membrane cavity profile according to claim 1, characterized in that, The maximum and minimum surface stress of the diaphragm compressor diaphragm when it deforms and comes into close contact with the membrane cavity surface are calculated using the following formula: In the formula, Young's modulus of the diaphragm material; Poisson's ratio of the diaphragm material; For diaphragm thickness; It is a mathematical integral operator; It is a mathematical differential operator; This refers to the radial normal stress of the diaphragm. The circumferential normal stress of the diaphragm; This refers to the radial shear stress of the diaphragm. This refers to the circumferential shear stress of the diaphragm. This represents the minimum stress on the diaphragm surface. This represents the maximum stress on the diaphragm surface.

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