Diaphragm compressor based on elliptical base rolled diaphragm cavity profile and its design method

Abstract

A diaphragm compressor based on an elliptical base rolling diaphragm cavity profile and a design method thereof. The diaphragm compressor has a diaphragm cavity designed and processed based on the elliptical base rolling diaphragm profile. The elliptical base rolling diaphragm profile establishes an XOY coordinate system along the major and minor axis directions of the ellipse HA. The rolling circle HB rolls on the outer surface of the ellipse HA. The rolling circle HB is tangent to the ellipse HA during the rolling process. A continuous curve that is tangent to the rolling circle HB and the ellipse HA is intercepted to form the diaphragm cavity profile. The present invention meets the design requirements of a continuous, monotonous, and slope-free diaphragm cavity profile for diaphragm compressors. The design principle avoids the generation of stress turning points on the diaphragm cavity profile, so that the diaphragm stress of the diaphragm compressor using the diaphragm cavity profile is uniform, continuous, and stress-free, which is beneficial to improving the operating reliability and service life of the diaphragm compressor. Compared with the traditional single-exponential profile, it has more design parameters and profile adjustability, and can improve the gas transmission characteristics, thermal performance, and volumetric efficiency of the diaphragm compressor.

Description

Technical Field

[0001] The present invention relates to the technical field of diaphragm compressors, and in particular to a diaphragm compressor based on an elliptical base rolled 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: the crankshaft connecting rod is driven by an electric motor, which drives the piston to reciprocate, thereby increasing and depressurizing the high-pressure oil. The high-pressure oil then pushes the diaphragm to compress and discharge the gas. Due to its good sealing and high pressure ratio, diaphragm compressors are widely used in the hydrogen energy industry, especially hydrogen refueling stations, which are one of its important usage scenarios. However, the diaphragm life, volumetric efficiency, and diaphragm head strength 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 can directly affect the reliability of the compressor operation. During the process of diaphragm damage, the main forms of damage are collapse, distortion, wear and cracks, and mechanical fatigue. Damage to the diaphragm will lead to the destruction of its mechanical properties, and in severe cases, it can even cause large economic losses.

[0003] At present, the most widely used diaphragm compressor cavity profile in China is the single-exponential, small-deflection cavity profile. After long-term practice and verification, it has good reliability and a practical basis. However, in the development and design of new diaphragm compressor models, the traditional single-exponential cavity profile is adjusted by three profile variables: cavity radius, single exponent, and maximum deflection. The profile optimization range is limited and cannot meet the urgent market needs of diaphragm compressor technology development and the development of new high-pressure, high-speed models. The multi-parameter and adjustable cavity profile optimization design can adjust the gas transmission characteristics, thermal characteristics, and volumetric efficiency of diaphragm compressors, and 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 address the above-mentioned problems in the prior art and provide a diaphragm compressor and a design method thereof based on an elliptical-based rolled diaphragm cavity profile, enrich the traditional single-exponential profile design optimization parameters, expand the optimization range, make the diaphragm cavity profile smooth and continuous and have many adjustable parameters, which can improve the reliability of the diaphragm compressor and increase the life of the diaphragm, and adapt to diversified market demands.

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

[0006] In the first aspect, a diaphragm compressor based on an elliptical base rolling circle diaphragm cavity profile is provided, which has a diaphragm cavity designed and processed based on the elliptical base rolling circle profile. The elliptical base rolling circle profile establishes an XOY coordinate system along the major axis and minor axis directions of the ellipse HA. The rolling circle HB rolls on the outer surface of the ellipse HA. The rolling circle HB is tangent to the ellipse HA during the rolling process. A continuous curve that is tangent to the rolling circle HB and the ellipse HA is intercepted to form the diaphragm cavity profile of the diaphragm compressor.

[0007] As a preferred solution, the line equation of the ellipse HA conforms to the following mathematical expression:

[0008]

[0009] Where x HA is the horizontal coordinate of the ellipse HA; y HA is the ordinate of the ellipse HA; a is the length of the semi-major axis of the ellipse HA; b is the length of the semi-minor axis of the ellipse HA; θ HA is the characteristic angle of the ellipse HA.

[0010] As a preferred solution, the profile equation of the rolling circle HB conforms to the following mathematical expression:

[0011]

[0012] Where x HB is the horizontal coordinate of the rolling circle HB; HB is the vertical coordinate of the rolling circle HB; R HB is the semi-major axis length of the rolling circle HB;

[0013] θ HB is the characteristic angle of the rolling circle HB.

[0014] As a preferred solution, in the curve section that is tangent to the rolling circle HB and the ellipse HA and is continuous, the tangent point P is obtained by solving the following expression:

[0015]

[0016] Where x P is the horizontal coordinate of point P; P is the vertical coordinate of point P; θ HA,P is the geometric characteristic angle of point P on the ellipse;

[0017] The tangent point P also satisfies the following mathematical expressions:

[0018]

[0019] The solution is to obtain a curve that is tangent to the rolling circle HB and the ellipse HA and is continuous;

[0020] The normal PON of the ellipse HA at the tangent point P conforms to the following expression:

[0021]

[0022] Where θ Pf is the inclination angle of the normal to the ellipse HA at the tangent point P.

[0023] As a preferred solution, define a point Q on the ellipse HA, and the tangent line of the ellipse HA at point Q is solved by the following expression:

[0024]

[0025] Where x Q is the horizontal coordinate of point Q; y Q is the vertical coordinate of point Q; θ Qq is the inclination angle of the tangent line of the ellipse HA at point Q;

[0026] Define a point A on the rolling circle HB, and the tangent line of the rolling circle HB at point A is solved by the following expression:

[0027]

[0028] Where x ON y is the horizontal coordinate of the center of the rolling circle ON; ON is the horizontal coordinate of the center of the rolling circle ON; x A is the horizontal coordinate of point A; A is the vertical coordinate of point A; θ Aq is the inclination angle of the tangent line of the rolling circle HB at point A;

[0029] The obtained elliptical arc segment PQ and circular arc segment AQ are spliced ​​together to form a complete and continuous curve segment APQ, thereby obtaining the membrane cavity profile of the diaphragm compressor.

[0030] As a preferred solution, the curve segment APQ needs to meet the following conditions:

[0031]

[0032] The curve segment APQ in the coordinate system XOY conforms to the following expression:

[0033]

[0034] Where, θ is the characteristic inclination angle in the XOY coordinate system; HO is the horizontal coordinate of curve segment APQ; HO is the vertical coordinate of curve segment APQ; the horizontal coordinate of curve segment APQ is x HO and the vertical coordinate y of the curve segment APQ HO The following conditions must be met:

[0035]

[0036] As a preferred solution, a coordinate system O'X'Y' is established with the tangent direction of point Q on the ellipse HA as the X axis, point Q as the coordinate origin, and the normal direction AON of point A on the rolling circle HB as the Y axis. The curve segment APQ passes through (x H ,y H ) The coordinates are described by the coordinates of the line points, and the membrane cavity line of the diaphragm compressor under the coordinate system O'X'Y' is obtained by the following coordinate transformation:

[0037]

[0038] In the formula, (x H ,y H ) represents the line coordinates of the curve segment APQ in the above coordinate system O'X'Y'; (x HO ,y HO ) represents the profile coordinates of the curve segment APQ in the original XOY coordinate system;

[0039] Thus, the complete line equation of the elliptical base rolling membrane cavity line H in the O'X'Y' coordinate system is obtained (x H ,y H ), and the slope angle of the elliptical base rolling profile H at the connection point of the elliptical profile HA and the rolling profile HB is solved by the following formula:

[0040]

[0041] With the inclination angle α P As the value increases, the gradient of diaphragm stress change becomes larger, which affects the stress distribution in the radial direction of the diaphragm.

[0042] As a preferred solution, the half-cavity volume VH enclosed by the diaphragm cavity profile of the diaphragm compressor is calculated by the following formula:

[0043]

[0044] Where R max - Maximum lumen radius, H(r) - Lumen profile equation with respect to radius r.

[0045] As a preferred solution, the maximum and minimum surface stresses of the diaphragm of the diaphragm compressor when deformed close to the membrane cavity surface are calculated as follows:

[0046]

[0047] σ min =min{σ Pr ±σ Mr ,σPt ±σ Mt}

[0048] σ max =max{σ Pr ±σ Mr ,σ Pt ±σ Mt}

[0049] Where, H is the diaphragm cavity profile of the diaphragm compressor; 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; ∫ represents the mathematical integral operator; d represents the mathematical differential operator; σ Pr is the radial normal stress of the diaphragm; σ Pt is the circumferential normal stress of the diaphragm; σ Mr is the radial shear stress of the diaphragm; σ Mr is the circumferential shear stress of the diaphragm; σ min is the minimum stress on the diaphragm surface; σ max is the maximum stress on the diaphragm surface.

[0050] In a second aspect, a design method for a diaphragm compressor based on an elliptical base rounded membrane cavity profile is provided, comprising the following steps:

[0051] Select the major axis a of the ellipse, the minor axis b of the ellipse, and the radius R of the rolling circle HB 、Tangent point P inclination angle θ P and the inclination angle θ of the characteristic point Q Q ;

[0052] According to the characteristic angle θ of the ellipse HA HA Characteristic angle θ with rolling circle HB HB Calculate and obtain the elliptical arc segment and its coordinate matrix HA' in the X'O'Y' coordinate system and the circular arc segment and its coordinate matrix HB' in the X'O'Y' coordinate system;

[0053] The membrane cavity profile of the diaphragm compressor under the calculated design parameters has the maximum membrane cavity deflection and the maximum membrane cavity radius, and the design inclination angle at the connection point of the membrane cavity profile of the diaphragm compressor is obtained to form the membrane cavity profile of the diaphragm compressor.

[0054] Compared with the prior art, the present invention has at least the following beneficial effects:

[0055] The membrane cavity profile of the diaphragm compressor is designed and processed based on the elliptical base rolling profile. During the profile construction process, an XOY coordinate system is established along the major axis and minor axis directions of the ellipse HA. The rolling circle HB rolls on the outer surface of the ellipse HA. The rolling circle HB is tangent to the ellipse HA during the rolling process. A continuous curve tangent to the rolling circle HB and the ellipse HA is intercepted, which meets the design requirements of the diaphragm compressor membrane cavity profile being continuous, monotonous and without a slope turning point. From the design principle, the generation of stress turning points on the membrane cavity profile is avoided, so that the stress of the diaphragm compressor diaphragm using the membrane cavity profile is uniform, continuous and without stress concentration, which is beneficial to improving the operating reliability and service life of the diaphragm compressor. The design parameters of the elliptical base rolling profile proposed in the present invention include the major axis a of the ellipse, the minor axis b of the ellipse, the rolling radius R HB 、Tangent point P inclination angle θ P and the inclination angle θ of the characteristic point Q Q Compared with the traditional single-exponential profile, it has more design parameters and profile adjustability, which is beneficial to improving the gas transmission characteristics, thermal performance and volumetric efficiency of the diaphragm compressor. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0057] Figure 1 Schematic diagram of the process of generating the elliptical base rolled membrane cavity profile in an embodiment of the present invention;

[0058] Figure 2 This is a schematic diagram showing the generation process and feature comparison of the elliptical base rolled membrane cavity profile in Example 1 of the present invention:

[0059] (a) is a schematic diagram of the generation process of the elliptical base rolled membrane cavity profile in Example 1 of the present invention;

[0060] (b) is a schematic diagram comparing the elliptical base rolled-round membrane cavity profile of Example 1 of the present invention and the conventional single-exponential membrane cavity profile;

[0061] (c) is a schematic diagram of the segmented combination of the elliptical base rolled-circular membrane cavity profile line according to Example 1 of the present invention;

[0062] Figure 3 This is a schematic diagram showing the generation process and feature comparison of the elliptical base rolled membrane cavity profile in Example 2 of the present invention:

[0063] (a) is a schematic diagram comparing the surface stress distribution of the diaphragm of a diaphragm compressor based on the elliptical base rolled diaphragm cavity profile of Example 2 of the present invention and the traditional single-exponential diaphragm cavity profile;

[0064] (b) is a schematic diagram comparing the elliptical base rolled-round membrane cavity profile of Example 2 of the present invention and the conventional single-exponential membrane cavity profile;

[0065] (c) is a schematic diagram of the segmented combination of the elliptical base rolled membrane cavity profile line in Example 2 of the present invention. DETAILED DESCRIPTION

[0066] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the embodiments described are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0067] See also Figure 1 In order to overcome the problems of insufficient optimization parameters and limited optimization range in traditional single-exponential profile design, an embodiment of the present invention proposes a diaphragm compressor based on an elliptical base rolling diaphragm cavity profile, which has a diaphragm cavity designed and processed based on the elliptical base rolling diaphragm profile. The elliptical base rolling diaphragm profile is smooth and continuous and has many adjustable parameters. It can adapt to diverse market demands, effectively improve the reliability of the diaphragm compressor, and increase the life of the diaphragm. The elliptical base rolling diaphragm profile establishes an XOY coordinate system along the major and minor axis directions of the ellipse HA. The rolling circle HB rolls on the outer surface of the ellipse HA. The rolling circle HB is tangent to the ellipse HA during the rolling process. A continuous curve that is tangent to the rolling circle HB and the ellipse HA is intercepted to form the diaphragm cavity profile of the diaphragm compressor. Since the curve characteristics of the elliptical base HA in the four quadrants of the XOY coordinate system are the same, the embodiment of the present invention only selects the characteristic profile of the rolling circle HB in the first quadrant of the XOY rolling on the surface of the ellipse HA for illustration.

[0068] Furthermore, the profile equation of the ellipse HA in the embodiment of the present invention conforms to the following mathematical expression:

[0069]

[0070] Where x HA is the horizontal coordinate of the ellipse HA; y HA is the ordinate of the ellipse HA; a is the length of the semi-major axis of the ellipse HA; b is the length of the semi-minor axis of the ellipse HA; θ HA is the characteristic angle of the ellipse HA.

[0071] Furthermore, the profile equation of the rolling circle HB in the embodiment of the present invention conforms to the following mathematical expression:

[0072]

[0073] Where x HB is the horizontal coordinate of the rolling circle HB; HB is the vertical coordinate of the rolling circle HB; RHB is the semi-major axis length of the rolling circle HB;

[0074] θ HB is the characteristic angle of the rolling circle HB.

[0075] Furthermore, the tangent point P between the ellipse HA and the rolling circle HB is defined and described by the following formula:

[0076]

[0077] Where x P is the horizontal coordinate of point P; P is the vertical coordinate of point P; θ HA,P is the geometric characteristic angle of point P on the ellipse.

[0078] The tangent point P also satisfies the following mathematical expressions:

[0079]

[0080] From this, the coordinates of the tangent point P can be solved.

[0081] Furthermore, the normal PON of the ellipse HA at the tangent point P conforms to the following expression:

[0082]

[0083] Where θ Pf is the inclination angle of the normal to the ellipse HA at the tangent point P.

[0084] Furthermore, a point Q on the ellipse HA is defined, and the tangent line XN of the ellipse HA at point Q is solved by the following formula:

[0085]

[0086] Where x Q is the horizontal coordinate of point Q; y Q is the vertical coordinate of point Q; θ Qq is the inclination angle of the tangent of the ellipse HA at point Q.

[0087] Furthermore, a point A on the rolling circle HB is defined, and the tangent line of the rolling circle HB at point A is solved by the following formula:

[0088]

[0089] Where x ON y is the horizontal coordinate of the center of the rolling circle ON; ON is the horizontal coordinate of the center of the rolling circle ON; x A is the horizontal coordinate of point A; A is the vertical coordinate of point A; θ Aq is the inclination angle of the tangent of the rolling circle HB at point A.

[0090] Furthermore, the obtained elliptical arc segment PQ and circular arc segment AQ are spliced ​​together to form a complete and continuous curve segment APQ, thereby obtaining the membrane cavity profile of the diaphragm compressor.

[0091] Furthermore, in order to satisfy the monotonic continuity and edge constraint stress conditions of the diaphragm compressor diaphragm cavity profile APQ, the curve segment APQ also needs to satisfy the following conditions:

[0092]

[0093] Furthermore, the curve segment APQ in the coordinate system XOY satisfies the following expression:

[0094]

[0095] Where, θ is the characteristic inclination angle in the XOY coordinate system; HO is the horizontal coordinate of curve segment APQ; HO is the vertical coordinate of the curve segment APQ; in order to meet the continuity condition of the curve segment APQ, the horizontal coordinate of the curve segment APQ x HO and the vertical coordinate y of the curve segment APQ HO Satisfies the following relationship:

[0096]

[0097] Furthermore, a coordinate system O'X'Y' is established with the tangent direction of point Q on the ellipse HA as the X axis, point Q as the coordinate origin, and the normal direction AON of point A on the rolling circle HB as the Y axis. The curve segment APQ passes through (x H ,y H ) The coordinates are described by the coordinates of the line points. The membrane cavity line of the diaphragm compressor under the coordinate system O'X'Y' is obtained by the following coordinate transformation:

[0098]

[0099] In the formula, (x H ,y H ) represents the line coordinates of the curve segment APQ in the above coordinate system O'X'Y'; (x HO ,y HO ) represents the profile coordinates of the curve segment APQ in the original XOY coordinate system.

[0100] Thus, the complete line equation of the elliptical base rolling membrane cavity line H in the O'X'Y' coordinate system is obtained (x H ,y H ), and the slope angle of the elliptical base rolling profile H at the connection point of the elliptical profile HA and the rolling profile HB is solved by the following formula:

[0101]

[0102] Furthermore, the slope angle of the connection point described in the above formula is an important parameter affecting the diaphragm stress of the diaphragm compressor using this profile. P The increase of the diaphragm stress gradient is greater, which directly affects the stress distribution characteristics in the radial direction of the diaphragm.

[0103] Furthermore, the semi-cavity volume VH enclosed by the diaphragm cavity profiles of different diaphragm compressors is calculated by the following formula:

[0104]

[0105] Where: R max - Maximum lumen radius.

[0106] Furthermore, the theoretical calculation formula for the maximum and minimum surface stresses of a 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:

[0107]

[0108]

[0109] σ min =min{σ Pr ±σ Mr ,σ Pt ±σ Mt}

[0110] σ max =max{σ Pr ±σ Mr ,σ Pt ±σ Mt}

[0111] Where, H is the diaphragm cavity profile of the diaphragm compressor; 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; ∫ represents the mathematical integral operator; d represents the mathematical differential operator; σ Pr is the radial normal stress of the diaphragm; σ Pt is the circumferential normal stress of the diaphragm; σ Mr is the radial shear stress of the diaphragm; σ Mr is the circumferential shear stress of the diaphragm; σ min is the minimum stress on the diaphragm surface; σ max is the maximum stress on the diaphragm surface.

[0112] The embodiment of the present invention is based on a diaphragm compressor of an elliptical base rolling diaphragm cavity profile. The design parameters of the elliptical base rolling profile include the elliptical major axis a, the elliptical minor axis b, the rolling radius RHB 、Tangent point P inclination angle θ P and the inclination angle θ of the characteristic point Q Q There are five design parameters in total. Compared with the traditional single-exponential profile, it has more design parameters and profile adjustability, which is beneficial to improving the gas transmission characteristics, thermal performance and volumetric efficiency of the diaphragm compressor; the profile is obtained by intercepting tangent line segments on the ellipse and the tangent rolling circle of its surface as the design profile of the diaphragm compressor diaphragm cavity, which meets the design requirements of the diaphragm compressor diaphragm cavity profile being continuous, monotonic and without slope turning points. From the design principle, it avoids the generation of stress turning points on the diaphragm cavity profile, so that the diaphragm stress of the diaphragm compressor using the diaphragm cavity profile is uniform and continuous, without stress concentration, which is beneficial to improving the operating reliability and service life of the diaphragm compressor.

[0113] Example 1

[0114] Example 1 of the present invention proposes a design method for a diaphragm compressor based on an elliptical base spherical membrane cavity profile, such as Figure 2 As shown, the major axis of the ellipse a = 8000 mm, the minor axis of the ellipse b = 200 mm, and the rolling radius R HB =1000mm, inclination angle θ at point P P =0.3° and the characteristic point Q inclination θ Q =0.2°, we can calculate:

[0115]

[0116] Where: θ HA - characteristic angle of the ellipse HA; θ HB - characteristic angle of rolling circle HB; HA'- elliptical arc segment and its coordinate matrix in X'O'Y' coordinate system; HB'- circular arc segment and its coordinate matrix in X'O'Y' coordinate system.

[0117] The membrane cavity profile under the design parameters has a maximum membrane cavity deflection of 4.3 mm as shown in the ordinate and a maximum membrane cavity radius of 140 mm as shown in the abscissa. The design inclination angle α of the connection point is calculated. P ≈145° (converting radians to degrees).

[0118] Furthermore, the traditional single-exponential diaphragm cavity profile consists of a complete and continuous profile. In general diaphragm compressors, the single-exponential diaphragm cavity profile equation can be described by the following formula:

[0119]

[0120] Where, HD is the single exponential membrane cavity line equation; ρ is the specific radius; H max -The maximum deflection of the single-exponential membrane cavity line; Z-the single-exponential membrane cavity line index.

[0121] Compared with the single-exponential membrane cavity profiles with the same maximum deflection and membrane cavity radius of Z=3, 5, and 7, the semi-cavity volume enclosed by the elliptical-based rolled membrane cavity profile in the embodiment of the present invention is smaller.

[0122] Example 2

[0123] Embodiment 2 of the present invention proposes a design method for a diaphragm compressor based on an elliptical base spherical membrane cavity profile, such as Figure 3 As shown, the major axis of the ellipse a = 8000 mm, the minor axis of the ellipse b = 500 mm, and the rolling radius R HB =2000mm, inclination angle θ at point P P =0.7° and the characteristic point Q inclination angle θ Q =0.65°, we can calculate:

[0124]

[0125] The membrane cavity profile under the design parameters has a maximum membrane cavity deflection of 1.7 mm as shown in the ordinate and a maximum membrane cavity radius of 100 mm as shown in the abscissa. The design inclination angle α of the connection point is calculated. P ≈155° (converting radians to degrees).

[0126] Compared with the single-exponential membrane cavity profiles with the same maximum deflection and membrane cavity radius of Z=3, 5, and 7, the semi-cavity volume enclosed by the elliptical-based rolled membrane cavity profile in the embodiment of the present invention is close to the semi-cavity volume enclosed by the single-exponential membrane cavity profile of Z=5.

[0127] Compared with the single-exponential membrane cavity profiles with the same maximum deflection and membrane cavity radius of Z=3, 5, and 7, the maximum stress on the surface of the diaphragm of the diaphragm compressor using the elliptical base rolled membrane cavity profile in the embodiment of the present invention is smaller and the stress distribution is more uniform.

[0128] Furthermore, the diaphragm compressor profile can be optimized by adjusting the design parameters in a multi-parameter and multi-objective manner to improve the geometric characteristics of the diaphragm compressor profile and the stress performance of the diaphragm, so that the designed diaphragm cavity can meet the gas transmission volume requirements while reducing the stress on the diaphragm, thereby increasing the life of the diaphragm compressor.

[0129] Although the present application has been 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 herein within the principles and scope of the present application. The scope of protection of the present application is determined by the appended claims, and the claims are intended to cover all modifications encompassed by the literal meaning or scope of equivalents of the technical features in the claims.

Claims

1. A diaphragm compressor based on an elliptical base spherical membrane cavity profile, characterized in that: The diaphragm compressor has a diaphragm cavity designed and processed based on an elliptical base rolling profile. The elliptical base rolling profile establishes an XOY coordinate system along the major and minor axis directions of the ellipse HA. The rolling circle HB rolls on the outer surface of the ellipse HA. The rolling circle HB is tangent to the ellipse HA during the rolling process. A continuous curve that is tangent to the rolling circle HB and the ellipse HA is intercepted to form the diaphragm compressor cavity profile. The line equation of the ellipse HA conforms to the following mathematical expression: Where, is the abscissa of the ellipse HA; is the ordinate of the ellipse HA; is the length of the semi-major axis of the ellipse HA; is the length of the semi-minor axis of the ellipse HA; is the characteristic angle of the ellipse HA; The profile equation of the rolling circle HB conforms to the following mathematical expression: Where, is the horizontal coordinate of the rolling circle HB; is the ordinate of the rolling circle HB; is the semi-major axis length of the rolling circle HB; is the characteristic angle of the rolling circle HB; In the curve section that is tangent to the rolling circle HB and the ellipse HA and is continuous, the tangent point P is obtained by solving the following expression: Where, is the horizontal coordinate of point P; is the ordinate of point P; is the geometric characteristic angle of point P on the ellipse; The tangent point P also satisfies the following mathematical expressions: The solution is to obtain a curve that is tangent to the rolling circle HB and the ellipse HA and is continuous; The normal PON of the ellipse HA at the tangent point P conforms to the following expression: Where, is the inclination angle of the normal of the ellipse HA at the tangent point P; Define a point Q on the ellipse HA, then the tangent line of the ellipse HA at point Q is solved by the following expression: Where, is the horizontal coordinate of point Q; is the vertical coordinate of point Q; is the inclination angle of the tangent line of the ellipse HA at point Q; Define a point A on the rolling circle HB, and the tangent line of the rolling circle HB at point A is solved by the following expression: Where, The horizontal coordinate of the center of the rolling circle ON; The horizontal coordinate of the center of the rolling circle ON; is the horizontal coordinate of point A; is the ordinate of point A; is the inclination angle of the tangent line of the rolling circle HB at point A; The obtained elliptical arc segment PQ and circular arc segment AQ are spliced ​​together to form a complete and continuous curve segment APQ, thereby obtaining the membrane cavity profile of the diaphragm compressor.

2. The diaphragm compressor based on the elliptical base spherical membrane cavity profile according to claim 1 is characterized in that: The curve segment APQ needs to meet the following conditions: The curve segment APQ in the coordinate system XOY conforms to the following expression: Where, is the characteristic inclination angle in the XOY coordinate system; is the abscissa of curve segment APQ; is the ordinate of curve segment APQ; APQ horizontal coordinate of curve segment and the vertical coordinate of the curve segment APQ The following conditions are met: 。 3. The diaphragm compressor based on the elliptical base spherical membrane cavity profile according to claim 1, characterized in that: The coordinate system O'X'Y' is established with the tangent direction of point Q on the ellipse HA as the X axis, point Q as the coordinate origin, and the normal direction AON of point A on the rolling circle HB as the Y axis. The curve segment APQ passes through the coordinate system O'X'Y'. The coordinates are described by the coordinates of the line points, and the membrane cavity line of the diaphragm compressor under the coordinate system O'X'Y' is obtained by the following coordinate transformation: Where, represents the profile coordinates of the curve segment APQ in the above coordinate system O'X'Y'; Indicates the profile coordinates of the curve segment APQ in the original XOY coordinate system; Thus, the coordinates of the complete line equation of the elliptical base rolling membrane cavity line H in the O'X'Y' coordinate system are obtained , and the slope angle of the elliptical base rolling line H at the connection point of the elliptical line HA and the rolling line HB is solved by the following formula: With the inclination As the value increases, the gradient of diaphragm stress change becomes larger, which affects the stress distribution in the radial direction of the diaphragm.

4. The diaphragm compressor based on the elliptical base spherical membrane cavity profile according to claim 2, characterized in that: The semi-cavity volume enclosed by the diaphragm cavity profile of the diaphragm compressor Calculated by the following formula: Where, - Maximum membrane cavity radius, -Equation of the membrane cavity profile with respect to radius r.

5. The diaphragm compressor based on the elliptical base spherical membrane cavity profile according to claim 2, characterized in that: The maximum and minimum surface stresses of the diaphragm of the diaphragm compressor when it deforms close to the membrane cavity surface are calculated as follows: Where, It is the diaphragm cavity profile of the diaphragm compressor; is the Young's modulus of the diaphragm material; is the Poisson's ratio of the diaphragm material; is the diaphragm thickness; Represents a mathematical integral operator; represents a mathematical differential operator; is the radial normal stress of the diaphragm; is the circumferential normal stress of the diaphragm; is the radial shear stress of the diaphragm; is the circumferential shear stress of the diaphragm; is the minimum stress on the diaphragm surface; is the maximum stress on the diaphragm surface.

6. A design method for a diaphragm compressor based on an elliptical base rounded membrane cavity profile as claimed in any one of claims 1 to 5, characterized in that: The following steps are involved: Select the major axis of the ellipse , minor axis of the ellipse , rolling radius , inclination angle of tangent point P and characteristic point Q inclination ; According to the characteristic angle of the ellipse HA Characteristic angle with rolling circle HB Calculate the elliptical arc segment and its coordinate matrix in the X'O'Y' coordinate system And the arc segment and its coordinate matrix in the X'O'Y' coordinate system ; The membrane cavity profile of the diaphragm compressor under the calculated design parameters has the maximum membrane cavity deflection and the maximum membrane cavity radius, and the design inclination angle at the connection point of the membrane cavity profile of the diaphragm compressor is obtained to form the membrane cavity profile of the diaphragm compressor.

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