A diaphragm compressor upper membrane head structure and a design method thereof

Abstract

A diaphragm compressor upper diaphragm head structure and a design method thereof, the upper diaphragm head is formed by combining and splicing involute segment B1B2, straight line segment B2B3, involute segment B3B4, involute segment B4B5, straight line segment B5B6 and involute segment B6B7 to form a diaphragm compressor diaphragm cavity profile line; the diaphragm cavity profile line is rotated around the center axis of the upper diaphragm head to obtain a diaphragm cavity surface S2, i.e. a gas side diaphragm cavity surface on the lower side of the upper diaphragm head, which comprises a surface S21 formed by rotating involute segment B1B2 and involute segment B6B7, a surface S22 formed by rotating straight line segment B2B3 and straight line segment B5B6, and a surface S23 formed by involute segment B3B4 and involute segment B4B5; an inclination angle is arranged between an air inlet valve cavity plane S3 on the upper side of the upper diaphragm head and an exhaust valve cavity plane S4; the involute segment is obtained by substituting basic generating equation of the involute into respective characteristic parameter base circle radius and base circle characteristic angle. The diaphragm compressor clearance volume is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of diaphragm compressor, in particular to a diaphragm compressor upper membrane head structure and a design method thereof. BACKGROUND

[0002] The diaphragm compressor is a kind of positive displacement compressor driven by a crank connecting rod mechanism, which pushes hydraulic oil by a piston, and the hydraulic oil pushes the diaphragm to move to realize the change of the membrane cavity volume, and the design of the membrane cavity profile is directly related to the service life of the diaphragm and the residual volume of the membrane cavity. Generally, the membrane cavity is a membrane cavity surface composed of a single exponential profile, and through long-term market practice, there is rich experience in application design of new models, but the single exponential profile has only three design parameters of membrane cavity radius, maximum deflection and membrane cavity index, which directly affects the stress distribution of the diaphragm in the movement process and the structure design of the membrane head. In order to adapt to the development of new models of diaphragm compressors under variable working conditions and multiple application scenarios, the development of membrane cavity profile with multiple design parameters is an important topic for current research and development of diaphragm compressors.

[0003] The residual volume of the diaphragm compressor membrane head structure directly affects the gas displacement and power consumption, especially when the compressed medium is hydrogen, because the hydrogen molecule is small and the heat transfer is fast, after the exhaust stroke of the diaphragm compressor, the high-temperature and high-pressure hydrogen in the residual volume is mixed with the hydrogen sucked in the suction stage, which causes the temperature of the suction gas to rise, directly affecting the volumetric efficiency and power consumption of the diaphragm compressor. In addition, in the development process of high-pressure, high-speed and large-displacement diaphragm compressors, the volumetric efficiency has a significant impact on the power consumption of the diaphragm compressor, and how to reduce the residual volume of the diaphragm compressor is also a difficult problem to be solved in the current research and development of diaphragm compressors. SUMMARY

[0004] The purpose of the present application is to solve the problems in the prior art, provide a diaphragm compressor upper membrane head structure and a design method thereof, which is beneficial to optimize the profile design, improve the design flexibility of the membrane cavity, reduce the residual volume of the diaphragm compressor and improve the overall performance.

[0005] In order to achieve the above purpose, the present application has the following technical scheme:

[0006] In a first aspect, a diaphragm compressor upper membrane head structure is provided, which is formed by combining a involute segment B1B2, a straight line segment B2B3, an involute segment B3B4, an involute segment B4B5, a straight line segment B5B6 and an involute segment B6B7 to form a diaphragm compressor membrane cavity profile L2, and the diaphragm compressor membrane cavity profile L2 is around the upper membrane head center axis Z of the point B4. S2The rotation obtains the film cavity profile S2, that is, the air side film cavity profile of the lower side of the upper film head, which includes the profile S21 formed by the rotation of the involute segment B1B2 and the involute segment B6B7, the profile S22 formed by the rotation of the straight line segment B2B3 and the straight line segment B5B6, and the profile S23 formed by the involute segment B3B4 and the involute segment B4B5; the gas inlet valve cavity plane S3 and the exhaust valve cavity plane S4 on the upper side of the upper film head are provided with an inclination angle θ K ; the involute segment B1B2, the involute segment B3B4, the involute segment B4B5, and the involute segment B6B7 are obtained by substituting the respective characteristic parameter base circle radius R fs and the base circle characteristic angle θ into the involute basic generating equation, and the involute basic generating equation is as follows:

[0007]

[0008] In the formula, x jk is the base circle involute abscissa; y jk is the base circle involute ordinate; R fs is the involute generating base circle radius; θ is the involute generating base circle characteristic angle; and the coordinate matrix P jk of the base circle involute is represented as:

[0009]

[0010] As a preferred scheme, the coordinate matrix P B1B2 of the involute segment B1B2 is obtained through the following coordinate transformation:

[0011]

[0012] In the formula, R fs,B1B2 is the generating circle radius of the involute segment B1B2; x B1B2 is the X-axis coordinate of the involute segment B1B2; and y B1B2 is the Y-axis coordinate of the involute segment B1B2.

[0013] The involute segment B1B2 and the straight line segment B2B3 satisfy the following relationship:

[0014]

[0015] By defining the length Δx line in the X-axis direction, the equation of the straight line segment B2B3 is:

[0016]

[0017] As a preferred scheme, the coordinate matrix P B3B4 of the involute segment B3B4 is obtained through the following coordinate transformation:

[0018]

[0019] The involute segment B3B4 and the straight line segment B2B3 satisfy the following profile design conditions:

[0020]

[0021] As a preferred scheme, the involute segment B4B5, the straight line segment B5B6 and the involute segment B6B7 are respectively designed by symmetry of the involute segment B3B4, the straight line segment B2B3 and the involute segment B1B2, and the coordinate change expression is as follows:

[0022]

[0023] The coordinate matrix P of the diaphragm compressor membrane cavity profile L2 L2 It is described by the following formula:

[0024] P L2 = [P B1B2 ,P B2B3 ,P B3B4 ,P B4B5 ,P B5B6 ,P B6B7 ].

[0025] As a preferred scheme, let R max = |x B1 -x B4 |, the diaphragm of the diaphragm compressor with the diaphragm compressor membrane cavity profile L2, the maximum and minimum surface stress of the diaphragm when deforming close to the upper membrane head membrane cavity profile S2 is calculated as follows:

[0026]

[0027] δ min = min{δ Pr ±δ Mr ,δ Pt ±δ Mt}

[0028] δ max = max{δ Pr ±δ Mr ,δ Pt ±δ Mt}

[0029] In the formula, y L2 is the longitudinal coordinate of the membrane cavity profile L2 with respect to x L2 ; 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 integral operation; d represents the differential operation; δ Pr is the radial normal stress of the diaphragm; δ Pt is the circumferential normal stress of the diaphragm; δMr is the radial shear stress of the diaphragm; δ Mr is the circumferential shear stress of the diaphragm; δ min is the minimum stress on the diaphragm surface; δ max is the maximum stress on the diaphragm surface.

[0030] As a preferred solution, a first air inlet valve chamber, a second air inlet valve chamber and an exhaust valve chamber are provided on the membrane head body; a first air inlet valve cavity hole is provided on the first air inlet valve chamber, a second air inlet valve cavity hole is provided on the second air inlet valve chamber, and an exhaust valve cavity hole is provided on the exhaust valve chamber for air intake and exhaust; a connecting bolt hole is provided on the membrane head body for fixed connection.

[0031] As a preferred solution, the pressure angle α of the involute segment B1B2 is defined as K =1.3°, and the base circle radius R of different involutes is obtained. fs The involute line segment cluster has the same end point inclination angle θ in the XOY coordinate system K ; The pressure angles generated by the involute segments B3B4, B4B5, and B6B7 are the same, i.e., α K =1.3°, realizing the connection and combination of line segments;

[0032] Define the length Δx of the straight line segment B2B3 in the X-axis direction line , the valve cavity diameter is R valve , satisfying Δx line >R valve In order to smoothly connect the straight line segment B2B3 with the involute segment B1B2 and the involute segment B3B4, the slope angle of the straight line segment B2B3 in the XOY coordinate system is equal to the end point inclination angle θ of the involute segment B1B2. K , which is the inclination angle of the starting point of the involute segment B3B4.

[0033] As a preferred solution, the base circle radius R is generated by adjusting the involutes of the involute segments B1B2, B3B4, B4B5, and B6B7. fs , generate pressure angle α K , adjust the stress distribution and maximum and minimum stress values ​​of the diaphragm compressor membrane cavity line L2, and adjust the Δx of the straight line segments B2B3 and B5B6 line The length realizes the change of the membrane cavity volume, thereby meeting the actual membrane cavity profile design requirements.

[0034] In a second aspect, a method for designing the upper diaphragm head structure of the diaphragm compressor is provided, comprising the following steps:

[0035] Determine the diaphragm compressor cavity volume through thermodynamic calculations, and determine the diaphragm material and strength requirements;

[0036] According to the development and design requirements, determine the basic design parameters of the involute segments B1B2, B3B4, B4B5 and B6B7, and generate the base circle radius R of the involute. fs and the generated pressure angle α K ;

[0037] According to the diaphragm compressor diaphragm cavity volume requirements, determine the length Δx of the straight line segment B2B3 and the straight line segment B5B6 in the X-axis direction line , and complete the design of the diaphragm compressor membrane cavity line L2; the diaphragm compressor membrane cavity line L2 is wound around the upper membrane head center axis Z of the longitudinal axis where point B4 is located. S2 Rotation obtains the membrane cavity profile S2.

[0038] As a preferred solution, the inlet and exhaust valve chamber of the upper diaphragm head is designed so that the inlet valve chamber is located in the straight line segment of the diaphragm compressor diaphragm chamber profile line L2, and the inlet valve chamber characteristic plane S1 is parallel to the straight line segment of the diaphragm compressor diaphragm chamber profile line L2, so as to reduce the clearance volume of the inlet valve chamber.

[0039] Compared with the prior art, the present invention has at least the following beneficial effects:

[0040] The upper diaphragm head diaphragm cavity profile formed by a combination of involute segments and straight line segments has the characteristics of flexible adjustment of multiple design parameters. Compared with the three design parameters of the traditional single-index diaphragm cavity profile, the diaphragm compressor diaphragm cavity profile L2 formed by the splicing combination of involute segments B1B2, straight line segments B2B3, involute segments B3B4, involute segments B4B5, straight line segments B5B6 and involute segments B6B7 has an adjustable generating base circle radius R of the involute segments B1B2 and B3B4. fs , generate pressure angle α K , the length Δx of the straight line segment B2B3 in the X-axis direction line There are five profile design parameters in total, and the profile design has greater flexibility. The diaphragm compressor diaphragm cavity profile L2 of the present invention can adjust the maximum and minimum stresses and stress distribution of the diaphragm by changing the design size of the involute segment, and adjust the volume of the diaphragm cavity profile by changing the characteristic length of the straight line segment, thereby realizing profile optimization strategies with different requirements and facilitating the serialized parameter design of the diaphragm compressor diaphragm cavity profile. The diaphragm compressor upper diaphragm head structure of the present invention, by arranging the intake valve cavity at the straight line segment of the diaphragm compressor diaphragm cavity profile L2, can reduce the clearance volume of the intake valve hole while satisfying the structural strength of the intake valve cavity, thereby improving the overall performance of the diaphragm compressor. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings needed to be used in the description of the specific embodiments or the prior art. Obviously, the drawings described below are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort on the basis of these drawings.

[0042] Fig. 1(a) is a schematic diagram of the structure of the vertical opening of the membrane cavity profile intake valve cavity of the conventional single-exponential membrane cavity;

[0043] Fig. 1(b) is a schematic diagram of the membrane cavity profile intake valve cavity opening of the membrane head structure of the diaphragm compressor according to the embodiment of the present application;

[0044] Figure 2 Fig. 2 is a schematic diagram of the membrane cavity profile L2 of the diaphragm compressor according to the embodiment of the present application in the XOY coordinate system;

[0045] Fig. 3(a) is a three-dimensional isometric side view of the diaphragm compressor head structure according to the embodiment of the present application from a first perspective;

[0046] Fig. 3(b) is a three-dimensional isometric side view of the diaphragm compressor head structure according to the embodiment of the present application from a second perspective;

[0047] Figure 4 Fig. 4 is a sectional view of the diaphragm compressor head structure according to the embodiment of the present application;

[0048] Figure 5 Fig. 5 is a profile cluster of the involute profile according to the embodiment of the present application with different base circle radii R fs and pressure angles α K = 1.3°;

[0049] Figure 6 Fig. 6 is a new membrane cavity profile cluster according to the embodiment of the present application, which is composed of the same involute segments and different linear segments with different characteristic lengths;

[0050] Figure 7 Fig. 7 is a diagram of the maximum and minimum stress distribution of the diaphragm of the diaphragm compressor membrane cavity structure according to the embodiment of the present application, which is composed of the same involute segments and different linear segments with different characteristic lengths.

[0051] In the drawings: J- upper membrane head structure; J11- first intake valve cavity; J111- first intake valve cavity hole; J12- second intake valve cavity; J121- second intake valve cavity hole; J2- exhaust valve cavity; J211- exhaust valve cavity hole; J3- connecting bolt hole; L1- traditional single exponential membrane cavity profile; L2- diaphragm compressor membrane cavity profile; S2- membrane cavity profile; S21- membrane cavity profile surrounded by first involute segment; S22- membrane cavity profile surrounded by straight line segment; S23- membrane cavity profile surrounded by second involute segment; S3- first intake valve cavity upper plane; XOY- profile characteristic coordinate system; Z S2 -B4 point on the longitudinal axis of the upper membrane head center axis; α K - generated pressure angle; Δx line - the length of the straight line segment of the profile in the X axis direction; R valve - valve cavity diameter; R fs - involute generating base circle radius; δ max - the maximum surface stress of the diaphragm compressor membrane cavity using the specific membrane cavity profile when the diaphragm is fitted with the membrane cavity profile; δ min - the minimum surface stress of the diaphragm compressor membrane cavity using the specific membrane cavity profile when the diaphragm is fitted with the membrane cavity profile; ρ- dimensionless radius of the membrane cavity. DETAILED DESCRIPTION

[0052] The technical solutions of the present application will be described below in conjunction with the embodiments, obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0053] Please refer to FIG. 1(a) and FIG. 1(b), the embodiment of the present application proposes a diaphragm compressor upper membrane head structure, which is composed of involute segment B1B2, straight line segment B2B3, involute segment B3B4, involute segment B4B5, straight line segment B5B6 and involute segment B6B7 to form diaphragm compressor membrane cavity profile L2; the diaphragm compressor membrane cavity profile L2 is around the upper membrane head center axis Z S2 rotating to obtain membrane cavity profile S2. Wherein, the basic generating equation of involute is as follows:

[0054]

[0055] In the formula, x jk is the horizontal coordinate of the base circle involute; y jk is the vertical coordinate of the base circle involute; R fs is the base circle radius of the involute; θ is the characteristic angle of the base circle of the involute; the coordinate matrix P jk of the base circle involute is:

[0056]

[0057] Establish as Figure 2 The coordinate system XOY shown in the figure can be obtained by changing the coordinates of the basic involute generation equation mentioned above to obtain the diaphragm compressor diaphragm cavity profile L2 in this coordinate system, wherein the involute segments B1B2, B3B4, B4B5 and B6B7 are obtained by substituting the basic involute generation equation mentioned above into their respective characteristic parameters, the base circle radius R. fs and the base circle characteristic angle θ are obtained, as described below.

[0058] Coordinate matrix P of involute segment B1B2 B1B2 Obtained by the following coordinate transformations:

[0059]

[0060] Where: R fs,B1B2 is the radius of the generating circle of the involute segment B1B2; x B1B2 is the X-axis coordinate of the involute segment B1B2; B1B2 is the Y-axis coordinate of the involute segment B1B2.

[0061] The involute segment B1B2 and the straight line segment B2B3 satisfy the following relationship:

[0062]

[0063] By defining the length Δx in the X-axis direction line , determine the equation of the straight line segment B2B3 as:

[0064]

[0065] Coordinate matrix P of involute segment B3B4 B3B4 Obtained by the following coordinate transformations:

[0066]

[0067] The involute segment B3B4 and the straight line segment B2B3 meet the following profile design conditions:

[0068]

[0069] The involute segment B4B5, the straight line segment B5B6 and the involute segment B6B7 are obtained by symmetrical design of the involute segment B3B4, the straight line segment B2B3 and the involute segment B1B2 respectively. The coordinate change expression is as follows:

[0070]

[0071] like Figure 2As shown, a new membrane cavity profile L2 is thus obtained, whose coordinate matrix P L2 may be described by the following formula:

[0072] P L2 = [P B1B2 ,P B2B3 ,P B3B4 ,P B4B5 ,P B5B6 ,P B6B7 ]

[0073] Let R max = |x B1 -x B4 |, the diaphragm of the diaphragm compressor having the membrane cavity profile L2, the maximum and minimum surface stresses of the diaphragm when deformed close to the upper membrane head membrane cavity profile S2 are calculated as follows:

[0074]

[0075] δ min = min{δ Pr ±δ Mr ,δ Pt ±δ Mt}

[0076] δ max = max{δ Pr ±δ Mr ,δ Pt ±δ Mt}

[0077] In the formula, y L2 is the longitudinal coordinate of the membrane cavity profile L2 with respect to x L2 ; 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 integral operation; d represents the differential operation; δ Pr is the radial normal stress of the diaphragm; δ Pt is the circumferential normal stress of the diaphragm; δ Mr is the radial shear stress of the diaphragm; δ Mr is the circumferential shear stress of the diaphragm; δ min is the minimum surface stress of the diaphragm; δ max is the maximum surface stress of the diaphragm.

[0078] As shown in Figure 3(a) and Figure 3(b), the upper diaphragm head structure of the diaphragm compressor of the embodiment of the present invention is provided with a first intake valve cavity J11, a second intake valve cavity J12 and an exhaust valve cavity J2 on the diaphragm head body J; a first intake valve cavity hole J111 is provided on the first intake valve cavity J11, a second intake valve cavity hole J121 is provided on the second intake valve cavity J12, and an exhaust valve cavity hole J211 is provided on the exhaust valve cavity J2 for air intake and exhaust; a connecting bolt hole J3 is provided on the diaphragm head body J for fixed connection. The diaphragm compressor diaphragm cavity line L2 is around the upper diaphragm head central axis Z of the longitudinal axis where point B4 is located. S2 The membrane cavity profile S2 is obtained by rotation, that is, the gas side membrane cavity profile on the lower side of the upper membrane head, including the profile S21 formed by the rotation of the involute segment B1B2 and the involute segment B6B7, the profile S22 formed by the rotation of the straight line segment B2B3 and the straight line segment B5B6, and the profile S23 formed by the involute segment B3B4 and the involute segment B4B5; an inclination angle θ is set between the intake valve cavity plane S3 and the exhaust valve cavity plane S4 on the upper side of the upper membrane head. K .

[0079] As shown in Figures 1(a) and 1(b), the conventional single-exponential diaphragm cavity profile consists of a single-exponential profile A1A2 and a symmetrical single-exponential profile A2A3. The exhaust valve cavity is located at the center of the diaphragm cavity profile L1, and the intake valve cavity is located at the inflection point of the diaphragm cavity profile L1. The intake valve cavity and the exhaust valve cavity axes are both vertical. The diaphragm compressor diaphragm cavity profile L2 of the embodiment of the present invention is designed so that the exhaust valve cavity is also located at the center of the diaphragm compressor diaphragm cavity profile L2, while the intake valve cavity is located at the profile straight line segment B2B3. The intake valve cavity axis is set perpendicular to the profile straight line segment B2B3, that is, the valve cavity lower plane S1 and the first intake valve cavity upper plane S3 and the diaphragm cavity profile S22 formed by the straight line segment are parallel. The angle between the conventional single-exponential profile intake valve axis and the diaphragm cavity profile intake valve axis of the embodiment of the present invention is equal to the inclination angle θ of the straight line B2B3. K , thereby reducing the suction clearance volume of the upper membrane head.

[0080] like Figure 5 As shown, the pressure angle α of the involute segment B1B2 is defined as K =1.3°, and the base circle radius R of different involutes is obtained. fs The involute line segment cluster has the same end point inclination angle θ in the XOY coordinate system K ; The pressure angles generated by the involute segments B3B4, B4B5, and B6B7 are the same, i.e., α K =1.3°, realizing the connection and combination of line segments.

[0081] like Figure 6 As shown, the length Δx of the straight line segment B2B3 in the X-axis direction is defined as line , the valve cavity diameter is Rvalve , satisfying Δx line >R valve In order to smoothly connect the straight line segment B2B3 with the involute segment B1B2 and the involute segment B3B4, the slope angle of the straight line segment B2B3 in the XOY coordinate system is equal to the end point inclination angle θ of the involute segment B1B2. K , that is, the starting inclination angle of the involute segment B3B4. The same involute segment B1B2, involute segment B3B4, involute segment B4B5, involute segment B6B7, different βx line The length of the membrane cavity line is as follows Figure 6 As shown, the diaphragm compressor diaphragm chamber volume can be adjusted thereby.

[0082] like Figure 7 As shown, the diaphragm thickness is set to 0.35mm, the diaphragm Poisson's ratio is set to 0.3, the diaphragm Young's modulus is set to 210GPa, and the involute generating base circle radius R of the involute segments B1B2, B3B4, B4B5, and B6B7 is set to fs =1000m, generating pressure angle α K =1.3°, through the theoretical mechanics calculation of the diaphragm, the profile is defined along the X direction Obtain the straight line segments B2B3 and B5B6 at different Δx line The stress of the membrane at the membrane cavity line L2 under the length is as follows Figure 7 As shown, it can be seen that the lengths of the straight line segments B2B3 and B5B6 do not directly affect the stress distribution of the membrane cavity line L2, satisfying δ max Δ[δ]=210MPa The maximum and minimum stresses do not change much. Therefore, in the actual development process of the diaphragm compressor cavity profile, it is only necessary to adjust the basic parameters for the generation of the involute segments B1B2, B3B4, B4B5, and B6B7, mainly including the radius R of the involute base circle. fs and the generated pressure angle α K , you can adjust the stress distribution and maximum and minimum stress values ​​of the diaphragm compressor membrane cavity line L2, adjust the Δx of the straight line segment B2B3 and the straight line segment B5B6 line The length realizes the change of the membrane cavity volume, thereby meeting the actual membrane cavity profile design requirements.

[0083] The embodiment of the present invention further provides a method for designing the upper diaphragm head structure of the diaphragm compressor, comprising the following steps:

[0084] S1. Determine the diaphragm compressor cavity volume through thermodynamic calculation, and determine the diaphragm material and strength requirements;

[0085] S2, determine the design basic parameters of the involute segment B1B2, the involute segment B3B4, the involute segment B4B5 and the involute segment B6B7 according to the development design requirements, and generate the involute generating base circle radius R fs And generate the pressure angle alpha K

[0086] S3, determine the length Delta x of the straight line segment B2B3 and the straight line segment B5B6 in the X-axis direction according to the diaphragm compressor membrane cavity volume requirement line , and complete the diaphragm compressor membrane cavity profile L2 design; rotate the diaphragm compressor membrane cavity profile L2 around the upper membrane head center axis Z of the longitudinal axis where the point B4 is located S2 To obtain the membrane cavity surface S2;

[0087] S4, design the inlet and exhaust valve cavities of the upper membrane head, so that the inlet valve cavity is located at the straight line segment of the diaphragm compressor membrane cavity profile L2, and the characteristic plane S1 of the inlet valve cavity and the straight line segment of the diaphragm compressor membrane cavity profile L2 are parallel, so as to reduce the clearance volume of the inlet valve cavity.

[0088] The diaphragm compressor upper membrane head structure and the design method thereof have the following advantages:

[0089] The novel membrane cavity profile has five profile design parameters, i.e., the involute segment B1B2 and the involute segment B3B4 adjustable generating base circle radius R fs , the pressure angle alpha K , the length Delta x of the straight line segment B2B3 line , so that the profile design has greater flexibility. The stress distribution of the diaphragm compressor diaphragm can be adjusted by changing the involute segment generating base circle radius and the pressure angle, the diaphragm compressor membrane cavity profile volume can be adjusted by changing the length of the straight line segment, so that the membrane cavity profile design meets the different design requirements of the diaphragm strength and the membrane cavity volume by adjusting different design parameters, which is beneficial to realize the parameter design series of the membrane cavity profile and has greater design flexibility. By arranging the inlet valve cavity at the straight line segment of the novel diaphragm compressor membrane cavity profile and making the axis of the inlet valve cavity perpendicular to the straight line segment of the membrane cavity profile, the clearance volume of the inlet valve cavity can be reduced, and the performance of the diaphragm compressor can be improved. Through the diaphragm compressor upper membrane head design of the application, smaller membrane cavity clearance volume and more flexible membrane cavity profile design can be realized, which is beneficial to improve the performance of the diaphragm compressor and reduce the development cost of new models.

[0090] ​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 upper membrane head structure, characterized in that: The diaphragm compressor cavity line L2 is formed by splicing the involute segment B1B2, the straight line segment B2B3, the involute segment B3B4, the involute segment B4B5, the straight line segment B5B6 and the involute segment B6B7; the diaphragm compressor cavity line L2 is centered around the upper diaphragm head center axis Z of the longitudinal axis where point B4 is located. S2 The membrane cavity profile S2 is obtained by rotation, that is, the gas side membrane cavity profile on the lower side of the upper membrane head, including the profile S21 formed by the rotation of the involute segment B1B2 and the involute segment B6B7, the profile S22 formed by the rotation of the straight line segment B2B3 and the straight line segment B5B6, and the profile S23 formed by the involute segment B3B4 and the involute segment B4B5; there is an inclination angle between the intake valve cavity plane S3 and the exhaust valve cavity plane S4 on the upper side of the upper membrane head. ; Involute segment B1B2, involute segment B3B4, involute segment B4B5, involute segment B6B7 are substituted into their respective characteristic parameters, base circle radius, through the basic involute generation equation and base circle characteristic angle The basic generating equation of the involute is obtained as follows: Where, is the abscissa of the base circle involute; is the ordinate of the base circle involute; Generate base circle radius for involute; Generate base circle characteristic angle for involute; Coordinate matrix of base circle involute Expressed as: Coordinate matrix of involute segment B1B2 Obtained by the following coordinate transformations: Where: is the radius of the generating circle of the involute segment B1B2; is the X-axis coordinate of the involute segment B1B2; is the Y-axis coordinate of the involute segment B1B2; The involute segment B1B2 and the straight line segment B2B3 satisfy the following relationship: By defining the length in the X-axis direction , determine the equation of the straight line segment B2B3 as: Coordinate matrix of involute segment B3B4 Obtained by the following coordinate transformations: The involute segment B3B4 and the straight line segment B2B3 meet the following profile design conditions: Define the pressure angle of the involute segment B1B2 , get different involute base circle radius The involute line segment cluster has the same end point inclination in the XOY coordinate system. ; The pressure angles generated by the involute segments B3B4, B4B5, and B6B7 are the same, that is, , realize the connection combination of line segments; Define the length of the straight line segment B2B3 in the X-axis direction , the valve cavity diameter is ,satisfy > In order to make the straight line segment B2B3 smoothly connected to the involute segment B1B2 and the involute segment B3B4, the slope angle of the straight line segment B2B3 in the XOY coordinate system is equal to the end point angle of the involute segment B1B2. , that is, the starting point inclination angle of the involute segment B3B4; Generate the base circle radius by adjusting the involutes of the involute segments B1B2, B3B4, B4B5, and B6B7 , generate pressure angle , adjust the stress distribution and maximum and minimum stress values ​​of the diaphragm compressor membrane cavity line L2, adjust the straight line segments B2B3 and B5B6 The length realizes the change of the membrane cavity volume, thereby meeting the actual membrane cavity profile design requirements.

2. The upper diaphragm head structure of the diaphragm compressor according to claim 1, characterized in that: The involute segment B4B5, the straight line segment B5B6 and the involute segment B6B7 are obtained by symmetrical design of the involute segment B3B4, the straight line segment B2B3 and the involute segment B1B2 respectively. The coordinate change expression is as follows: Coordinate matrix of diaphragm compressor diaphragm cavity line L2 It is described by the following formula: 。 3. The upper membrane head structure of the diaphragm compressor according to claim 2, characterized in that: make The maximum and minimum surface stresses of the diaphragm compressor diaphragm having the diaphragm compressor cavity profile line L2 when deformed close to the upper diaphragm head cavity profile S2 are calculated as follows: Where, For about The vertical coordinate of the membrane cavity line L2; is the Young's modulus of the diaphragm material; is the Poisson's ratio of the diaphragm material; is the diaphragm thickness; Indicates integral operation; represents differential operation; 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.

4. The upper diaphragm head structure of the diaphragm compressor according to claim 1, characterized in that: A first air inlet valve chamber (J11), a second air inlet valve chamber (J12) and an exhaust valve chamber (J2) are provided on the membrane head body (J); a first air inlet valve chamber hole (J111) is provided on the first air inlet valve chamber (J11), a second air inlet valve chamber hole (J121) is provided on the second air inlet valve chamber (J12), and an exhaust valve chamber hole (J211) is provided on the exhaust valve chamber (J2) for air intake and exhaust; a connecting bolt hole (J3) is provided on the membrane head body (J) for fixed connection.

5. A method for designing an upper diaphragm head structure of a diaphragm compressor according to any one of claims 1 to 4, characterized in that: The following steps are involved: Determine the diaphragm compressor cavity volume through thermodynamic calculations, and determine the diaphragm material and strength requirements; Determine the design basic parameters of involute segments B1B2, B3B4, B4B5 and B6B7 according to the development and design requirements, and generate the base circle radius of the involute. and generate pressure angle ; According to the diaphragm compressor diaphragm cavity volume requirements, determine the length of straight line segments B2B3 and B5B6 in the X-axis direction , and complete the design of the diaphragm compressor membrane cavity line L2; the diaphragm compressor membrane cavity line L2 is wound around the upper membrane head center axis Z of the longitudinal axis where point B4 is located. S2 Rotation obtains the membrane cavity profile S2.

6. The design method according to claim 5, characterized in that: The inlet and exhaust valve chamber of the upper diaphragm head is designed so that the inlet valve chamber is located in the straight line segment of the diaphragm compressor diaphragm chamber profile line L2, and the inlet valve chamber characteristic plane S1 is parallel to the straight line segment of the diaphragm compressor diaphragm chamber profile line L2 to reduce the clearance volume of the inlet valve chamber.

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