Diaphragm compressor based on double-tangent arc diaphragm cavity molded line and design method thereof

Abstract

According to the diaphragm compressor based on the double-tangent-arc diaphragm cavity molded line and the design method of the diaphragm compressor, the diaphragm compressor is provided with a diaphragm cavity designed and machined based on the double-tangent-arc molded line, the double-tangent-arc molded line is composed of a first circular-arc molded line HA and a second circular-arc molded line HB which are continuous, and the first circular-arc molded line HA and the second circular-arc molded line HB are connected and tangent at the connecting position. The stress distribution of the diaphragm compressor can be adjusted by adjusting the design parameters of the first arc molded line HA, and by means of molded line parameter design and diaphragm cavity curved surface optimization based on theoretical mechanical analysis, the diaphragm compressor has smaller stress than a traditional single-index molded line under the same design parameters of the diaphragm cavity volume, the service life of a diaphragm of the diaphragm compressor is prolonged, and the service life of the diaphragm compressor is prolonged. The whole machine reliability is improved. The diaphragm cavity designed and machined based on the double-tangent arc molded line has more molded line design parameters, the molded line design flexibility of the diaphragm compressor is improved, and the problems that traditional single-index molded line design is insufficient in optimization parameter and limited in optimization range can be solved.

Description

Technical Field

[0001] The invention belongs to the technical field of diaphragm compressors, and in particular relates to a diaphragm compressor based on a double-tangent arc diaphragm cavity profile 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 to drive the crankshaft connecting rod through a motor, drive the piston to reciprocate to achieve the pressurization and decompression of the high-pressure oil, and then use the high-pressure oil to push the diaphragm to achieve gas compression and discharge. Diaphragm compressors are widely used in the hydrogen energy industry due to their good sealing and large pressure ratio. In particular, hydrogen refueling stations are one of their important usage scenarios. The diaphragm life, volumetric efficiency and diaphragm head strength issues are very critical and difficult issues in the development of diaphragm compressors. The diaphragm is a key component in the stable operation of the diaphragm compressor, and its working performance directly affects the reliability of the compressor operation. In the process of diaphragm damage, the main forms of damage are collapse, distortion, wear and cracks, and mechanical fatigue. The damage of the diaphragm will cause its mechanical properties to be destroyed, and severe cases may even cause large economic losses.

[0003] 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 cannot adapt to the urgent needs of the technical development of diaphragm compressors and the research and 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

[0004] The purpose of the present invention is to provide a diaphragm compressor based on a double-cut arc diaphragm cavity profile and a design method thereof in order to address the problems in the above-mentioned prior art, increase the flexibility of the diaphragm compressor profile design, and improve the diaphragm life and the reliability of the entire machine.

[0005] In order to achieve the above object, the present invention has the following technical solutions:

[0006] In a first aspect, a diaphragm compressor based on a double-cut arc diaphragm cavity profile is provided, which has a diaphragm cavity designed and processed based on the double-cut arc profile, wherein the double-cut arc profile is composed of a continuous first arc profile HA and a second arc profile HB, and the first arc profile HA and the second arc profile HB are connected and tangent at the connection.

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

[0008]

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

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

[0011]

[0012] In the formula, XO first YO is the horizontal coordinate of the center of the first arc line HA; first is the ordinate of the center of the first arc line HA; R first is the radius of the first circular arc line HA.

[0013] As a preferred solution, the design of the first arc profile HA satisfies the following conditional expression:

[0014]

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

[0016] As a preferred solution, the specific radius ρ is defined as follows:

[0017]

[0018] Then the mathematical expression of the first arc profile equation HA is as follows:

[0019]

[0020] The mathematical expression of the second arc profile equation HB is as follows:

[0021]

[0022] In the formula, XO second YO is the horizontal coordinate of the center of the second arc line HB; second is the ordinate of the center of the second arc line HB; R second is the radius of the second arc profile line HB.

[0023] As a preferred solution, the design of the second arc profile equation HB satisfies the following conditional expression:

[0024]

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

[0026]

[0027] As a preferred solution, the membrane cavity designed and processed based on the double-cut arc profile is calculated according to the following formula to calculate the half cavity volume VH:

[0028]

[0029] As a preferred solution, the maximum and minimum surface stresses of the diaphragm of the diaphragm compressor when deformed close to the diaphragm cavity surface are calculated as follows:

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

[0034] In a second aspect, a design method for a diaphragm compressor based on a double-tangent arc diaphragm cavity profile is provided, comprising the following steps:

[0035] By adjusting the design parameters of the first arc profile HA, the stress distribution of the diaphragm compressor is adjusted;

[0036] By adjusting the stress distribution of the diaphragm compressor, it is avoided that the stress concentration of the through holes on the diaphragm compressor oil distribution plate and the diaphragm compressor cylinder cover coincides with the position of the maximum stress of the diaphragm cavity profile.

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

[0038] The diaphragm cavity of the diaphragm compressor of the present invention is designed and processed based on a double-tangent circular arc profile, and the double-tangent circular arc profile is composed of a continuous first circular arc profile HA and a second circular arc profile HB, and 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. Through the profile parameter design and diaphragm cavity surface optimization based on theoretical mechanics analysis, it can have a smaller stress than the traditional single-exponential profile under the design parameters of the same diaphragm cavity volume, which is beneficial to improve the life of the diaphragm of the diaphragm compressor and improve the reliability of the whole machine. The diaphragm cavity designed and processed based on the double-tangent circular arc profile of the present invention has more profile design parameters than the traditional single-exponential profile, which increases the flexibility of the diaphragm compressor profile design, and through reasonable profile optimization design, it is beneficial to reduce the manufacturing cost of the diaphragm compressor and improve the market competitiveness of the product. In the actual diaphragm compressor diaphragm cavity design, by adjusting the stress distribution of the diaphragm compressor, the stress concentration of the through holes on the diaphragm compressor oil distribution plate and the diaphragm compressor cylinder head is avoided to coincide with the position of the maximum stress of the diaphragm cavity profile, providing guidance for the research and development of diaphragm compressors using double-tangent circular arc diaphragm cavity profiles. The diaphragm compressor based on the double-tangent circular arc diaphragm cavity profile of the present invention can overcome the problems of insufficient optimization parameters and limited optimization range of the traditional single-exponential profile design, adapt to diverse market demands, optimize the reliability of diaphragm compressors and increase the life of diaphragms. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] 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.

[0040] Figure 1 The radius R of the first arc line HA in the embodiment of the present invention is first =6000mm double-cut arc membrane cavity profile diagram;

[0041] Figure 2 The radius R of the conventional single-index membrane cavity profile and the first arc profile HA with index Z=3, 5, 7 in the embodiment of the present invention is first = 3000mm, 5000mm, 6000mm, 7000mm double-cut arc membrane cavity profile diagram;

[0042] Figure 3The radius R of the conventional single-index membrane cavity profile and the first arc profile HA with index Z=3, 5, 7 in the embodiment of the present invention is first = Schematic diagram of the half-cavity volume of the membrane cavity surrounded by the double-cut arc membrane cavity profile of 3000mm, 5000mm, 6000mm, and 7000mm;

[0043] Figure 4 Schematic diagram of maximum and minimum stresses on the diaphragm surface of a diaphragm compressor using a traditional single-index diaphragm cavity profile with index Z=3, 5, and 7 according to an embodiment of the present invention;

[0044] Figure 5 The radius R of the first arc profile HA used in the embodiment of the present invention is first =Schematic diagram of maximum and minimum stress on the diaphragm surface of diaphragm compressor with double-cut arc diaphragm cavity profiles of 3000mm, 5000mm, 6000mm and 7000mm. DETAILED DESCRIPTION

[0045] 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.

[0046] See also Figure 1 An embodiment of the present invention proposes a diaphragm compressor based on a double-tangent circular arc diaphragm cavity profile, which has a diaphragm cavity designed and processed based on a double-tangent circular arc profile H. The double-tangent 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.

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

[0048]

[0049] Where H(r) is the equation of the double tangent arc profile; HA(r) is the equation of the first arc profile; HB(r) is the equation of the second arc profile; r is the radius of the membrane cavity; x p R is the ratio of the membrane cavity radius corresponding to the first arc profile to the maximum membrane cavity radius; max is the maximum membrane cavity radius.

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

[0051]

[0052] In the formula, XO firstYO is the horizontal coordinate of the center of the first arc line HA; first is the ordinate of the center of the first arc line HA; R first is the radius of the first circular arc line HA.

[0053] The design of the first arc profile HA satisfies the following conditional expression:

[0054]

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

[0056] Furthermore, the specific radius ρ is defined as follows:

[0057]

[0058] Then the mathematical expression of the first arc profile equation HA is as follows:

[0059]

[0060] Similarly, the mathematical expression of the second arc profile equation HB is as follows:

[0061]

[0062] In the formula, XO second YO is the horizontal coordinate of the center of the second arc line HB; second is the ordinate of the center of the second arc line HB; R second is the radius of the second arc profile line HB.

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

[0064]

[0065] The first arc-shaped line HA and the second arc-shaped line HB are connected and tangent at the connection point to satisfy the following expression:

[0066]

[0067] In a possible implementation manner, the half-cavity volume VH of the membrane cavity designed and processed based on the double-cut arc profile is calculated according to the following formula:

[0068]

[0069] Furthermore, the maximum and minimum surface stresses of the diaphragm compressor diaphragm using the diaphragm cavity profile of the present invention when deformed close to the diaphragm cavity profile are calculated as follows:

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

[0074] Another embodiment of the present invention further provides a design method for a diaphragm compressor based on a double-tangent arc diaphragm cavity profile, which mainly includes the following steps:

[0075] By adjusting the design parameters of the first arc profile HA, the stress distribution of the diaphragm compressor is adjusted;

[0076] By adjusting the stress distribution of the diaphragm compressor, it is avoided that the stress concentration of the through holes on the diaphragm compressor oil distribution plate and the diaphragm compressor cylinder cover coincides with the position of the maximum stress of 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 an external force, the local stress increases significantly due to a sudden change in shape, size or structure.

[0078] In a diaphragm compressor, if the stress concentration of the through hole on the oil distribution plate and the cylinder head coincides with the position of the maximum stress of the diaphragm cavity profile, the stress level in this area will further increase, thereby increasing the risk of structural damage. Areas with stress concentration are more prone to structural damage, such as cracks and fractures. Therefore, avoiding the coincidence of stress concentration and the maximum stress point can ensure the overall structural strength of the diaphragm compressor and prevent structural failure caused by excessive local stress.

[0079] At the same time, long-term operation in a high-stress environment will accelerate material fatigue and aging, thereby reducing the durability of the equipment. By optimizing the structural design and avoiding the overlap of stress concentration and maximum stress, the service life of the diaphragm compressor can be extended.

[0080] In addition, stress concentration may cause vibration, noise and other problems in the diaphragm compressor during operation, affecting the normal operation and performance of the equipment. Therefore, it is of great significance to reasonably design the structure to avoid stress concentration in order to improve the overall performance of the equipment. Stress concentration may 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 can be ensured that the diaphragm compressor can operate stably under various working conditions.

[0081] In actual operation and maintenance, avoiding the overlap of stress concentration and maximum stress can reduce the probability of equipment failure during operation, thereby reducing the maintenance difficulty and workload of operators. Since stress concentration is one of the main causes of equipment failure and damage, avoiding this problem by optimizing the structural design can significantly reduce the maintenance cost and downtime of the equipment.

[0082] Further comparison and verification show that the traditional single-exponential diaphragm cavity profile is composed of a complete and continuous profile. The single-exponential diaphragm cavity profile equation used in general diaphragm compressors can be described by the following formula:

[0083]

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

[0085] See also Figure 2 , compare the membrane cavity profiles with different single index membrane cavity profile indexes Z = 3, 5, and 7, and the radius R of the first arc profile HA first =3000mm, 5000mm, 6000mm, 7000mm double-tangent arc membrane cavity profile, calculate the half cavity volume VH surrounded by different membrane cavity profiles. Figure 3 , take the maximum radius R of the membrane cavity max =360mm, maximum deflection of membrane cavity H max =8mm, the semi-cavity volume VH of the single-index diaphragm cavity line increases with the increase of index Z, and the semi-cavity volume VH of the double-cut arc diaphragm cavity line increases with the radius R of the first arc diaphragm line. first The single exponential membrane cavity line and R first =6000mm double-cut arc membrane cavity profile has the same membrane cavity half-cavity volume.

[0086] like Figures 4 to 5 As shown in the figure, through theoretical mechanical analysis and calculation, the maximum stress σ of the diaphragm surface of the diaphragm compressor using the above different diaphragm cavity profiles is obtained. max and the minimum value σ min By comparison, it can be seen that the maximum stress of the double arc membrane cavity profile under the same membrane cavity radius is less than the yield strength of the general membrane material 210MPa, while the maximum stress of the traditional single index membrane cavity profile σ max Close to 250MPa, which shows that under this design condition, the double arc membrane cavity line has a smaller maximum stress σ max , which is beneficial to improve the stress condition of the diaphragm.

[0087] The diaphragm compressor based on the double-cut arc diaphragm cavity profile in the embodiment of the present invention can have smaller stress under the design parameters of the same diaphragm cavity volume than the traditional single-exponential profile, by improving the diaphragm cavity curved surface and design parameters, thereby helping to increase the life of the diaphragm compressor diaphragm and improve the reliability of the entire machine. Reasonable profile optimization design is also helpful in reducing the manufacturing cost of the diaphragm compressor and improving the market competitiveness of the product.

[0088] 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 diaphragm compressor based on a double-tangent arc diaphragm cavity profile, characterized in that: The membrane cavity is designed and processed based on a double-tangent arc line, wherein the double-tangent arc line is composed of a continuous first arc line HA and a second arc line HB, and the first arc line HA and the second arc line HB are connected and tangent at the connection.

2. The diaphragm compressor based on the double-tangent arc diaphragm cavity profile according to claim 1 is characterized in that: The double tangent arc profile conforms to the following profile equation: Where H(r) is the equation of the double tangent arc profile; HA(r) is the equation of the first arc profile; HB(r) is the equation of the second arc profile; r is the radius of the membrane cavity; x p R is the ratio of the membrane cavity radius corresponding to the first arc profile to the maximum membrane cavity radius; max is the maximum membrane cavity radius.

3. The diaphragm compressor based on the double-tangent arc diaphragm cavity profile according to claim 2 is characterized in that: The mathematical expression of the first arc profile equation HA(r) is as follows: In the formula, XO first YO is the horizontal coordinate of the center of the first arc line HA; first is the ordinate of the center of the first arc line HA; R first is the radius of the first circular arc line HA.

4. The diaphragm compressor based on the double-tangent arc diaphragm cavity profile according to claim 3 is characterized in that: The design of the first arc profile HA satisfies the following conditional expression: In the formula, H max It is the maximum value of the ordinate of the first circular arc line HA.

5. The diaphragm compressor based on the double-tangent arc diaphragm cavity profile according to claim 4 is characterized in that: Define the specific radius ρ as follows: Then the mathematical expression of the first arc profile equation HA is as follows: The mathematical expression of the second arc profile equation HB is as follows: In the formula, XO second YO is the horizontal coordinate of the center of the second arc line HB; second is the ordinate of the center of the second arc line HB; R second is the radius of the second arc profile line HB.

6. The diaphragm compressor based on the double-tangent arc diaphragm cavity profile according to claim 5 is characterized in that: The design of the second arc profile equation HB satisfies the following conditional expression:

7. The diaphragm compressor based on the double-tangent arc diaphragm cavity profile according to claim 6 is characterized in that: The first arc-shaped line HA and the second arc-shaped line HB are connected and tangent at the connection point to satisfy the following expression:

8. The diaphragm compressor based on the double-tangent arc diaphragm cavity profile according to claim 7 is characterized in that: The membrane cavity designed and processed based on the double-cut arc profile is calculated by the following formula to calculate the half cavity volume VH:

9. The diaphragm compressor based on the double-tangent arc diaphragm cavity profile according to claim 7, characterized in that: 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: s min =min{σ Pr ±σ Mr ,s Pt ±σ Mt } s max =max{σ Pr ±σ Mr ,s Pt ±σ Mt } Where, E is the Young's modulus of the diaphragm material; μ is the Poisson's ratio of the diaphragm material; t is the thickness of the diaphragm; ∫ is the mathematical integral operator; d is the mathematical differential operator; σ Pr is the radial normal stress of the diaphragm; σ Pt is the circumferential normal stress of the diaphragm; Mr is the radial shear stress of the diaphragm; Mr is the circumferential shear stress of the diaphragm; min is the minimum stress on the diaphragm surface; σ max is the maximum stress on the diaphragm surface.

10. A design method for a diaphragm compressor based on a double-tangent arc diaphragm cavity profile as claimed in any one of claims 1 to 9, characterized in that: The following steps are involved: By adjusting the design parameters of the first arc profile HA, the stress distribution of the diaphragm compressor is adjusted; By adjusting the stress distribution of the diaphragm compressor, it is avoided that the stress concentration of the through holes on the diaphragm compressor oil distribution plate and the diaphragm compressor cylinder cover coincides with the position of the maximum stress of the diaphragm cavity profile.

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