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A design method for back pressure flat cover

A design method and technology of flat cover, applied in computer-aided design, calculation, instrument, etc., can solve problems such as no provision, no positive pressure flat cover for maintenance, insufficient structural strength of back pressure flat cover, etc., to reduce maintenance cost, Control the effect of installation and maintenance cycle

Active Publication Date: 2022-01-28
HARBIN ELECTRIC CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The back pressure flat cover has the advantages of compact structure, and the same condition requires less metal than the positive pressure flat cover, that is, the economy is better; in addition, it is easier to achieve sealing, but the disadvantage is that the maintenance is not as convenient as the positive pressure flat cover. Because the back pressure flat cover is installed inside the equipment, the operator must enter the inside of the equipment to observe the positive pressure flat cover, and then carry out maintenance work
[0005] At present, there is no rule design method given in the pressure vessel design standard specification (GB150) for the strength check and design of flat cover components subject to back pressure, and there is no similar case support. Therefore, when carrying out this type of structure, the designer adopts The calibration methods are different, and the use of these different design methods will easily lead to insufficient structural strength of the back pressure flat cover, which will lead to the pressure vessel designed with the back pressure flat cover unable to guarantee the sealing reliability. Therefore, it is urgent to propose a standardized pressure vessel The strength design and checking method of the back pressure-bearing flat cover to ensure the safety and sealing reliability of such pressure-bearing components

Method used

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  • A design method for back pressure flat cover
  • A design method for back pressure flat cover
  • A design method for back pressure flat cover

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specific Embodiment approach 1

[0076] Specific implementation mode 1: A method for designing a flat cover with back pressure in this embodiment, the size parameters of the flat cover under back pressure are: the total thickness of the flat cover B, the thickness of the stepped section b, the back pressure is P, and the calculated pressure is Pc , the diameter of the force center circle of the gasket is Dg, the outer diameter of the gasket contact circle is D2, the inner diameter of the gasket contact circle is D1, the diameter of the dangerous section of the step is Da, and the radius of the transition circle at the corner of the step is R.

[0077] A method for designing a back pressure-bearing flat cover, comprising the following steps:

[0078] Step 1: Calculate the diameter Dg of the center circle of the gasket pressing force;

[0079] Step 2: Calculate the total thickness B value of the flat cover;

[0080] Step 3: Calculate the total force W on the back of the flat cover due to the calculated pressur...

specific Embodiment approach 2

[0128] Specific implementation mode 2: A design method for a back pressure flat cover in this implementation mode, the description is attached Figure 4 It is a high-pressure accumulator product of a certain cubic meter, the design conditions: the design calculation pressure is 33MPa, the design temperature is 70°C, the material of the flat cover is 20MnMoIII, and the allowable stress of the material at the design temperature is 196MPa (according to GB150.2),

[0129] Among them, the size of the sealing pure copper gasket: D2 is Φ430mm, D1 is Φ410mm, the thickness δ is 5mm, flat cover, the specific size is detailed in the appendix of the manual Figure 5 ;

[0130] 1. According to the design method of the pressure vessel design standard GB150.3 flange, the diameter Dg of the center circle of the gasket pressing force is obtained;

[0131] Gasket contact surface width N=(430-410) / 2=10mm;

[0132] Gasket basic sealing width b0=N / 2=10 / 2=5mm;

[0133] Gasket effective sealing w...

specific Embodiment approach 3

[0165] Specific implementation mode three: a method for designing a back pressure-bearing flat cover according to this implementation mode,

[0166] Structural numerical method verification, combined with the calculation results of the second embodiment, applies the finite element method to calculate the load of the structure, obtains the stress value of the structure, and uses the stress classification method to perform safety assessment to verify the correctness of the above calculation results.

[0167] 1. Input conditions

[0168] The structure size is attached according to the manual Figure 5 , the calculated pressure and the maximum working pressure are both 33MPa, the design temperature is 70 ℃, the gasket material is pure copper, and the elastic modulus of the material at the design temperature is:

[0169]

[0170] The finite element method application program is ANSYS15.0, the calculation model is a plane axisymmetric body element, the element type is PLANE183, ...

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Abstract

The invention relates to a method for designing a back pressure flat cover, which belongs to the technical field of strength design of a pressure vessel flat cover. The invention aims to solve the strength check and design method of the existing back pressure sealed flat cover structure. The present invention comprises step 1: calculating the central circle diameter Dg of the pressing force of the gasket; step 2: calculating the total thickness B value of the flat cover; step 3: obtaining the total force W on the back of the flat cover due to the calculated pressure Pc , and according to the force balance condition, the total force value is equal to the force F acting on the gasket; Step 4: Check the strength of the most dangerous working section of the flat cover. The design method of the back pressure flat cover can solve the problem of insufficient stability of the back pressure flat cover caused by the existing structural design of the back pressure flat cover, thereby effectively controlling the installation and maintenance cycle of the back pressure flat cover of the pressure vessel and reducing maintenance cost.

Description

technical field [0001] The invention relates to a method for designing the strength of a back pressure-bearing flat cover, belonging to the technical field of strength design for a flat cover of a pressure vessel. Background technique [0002] Flat caps subjected to back pressure, the structure of which is shown in figure 1 , the gasket and the pressure-bearing surface are on different surfaces of the flat cover, also known as self-tightening flat cover. The pressure-bearing characteristic is that when the pressure increases, if there is no limit mechanism at the gasket structure, the gasket compression force will increase with increasing pressure. This situation is more in line with the principle of sealing, so it is called a self-tightening flat cover. [0003] Positive pressure flat cover such as figure 2 , the gasket and the pressure-bearing surface are on the same side of the flat cover, and the gasket compression force is realized by the bolt tightening force. The ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G06F30/17G06F119/14
CPCG06F30/17G06F2119/06
Inventor 徐树林邱砚明牟力波支南刘艳鹏武君车东光
Owner HARBIN ELECTRIC CO LTD
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