A gasket creep relaxation performance prediction method, device and storage medium

Abstract

The present application relates to a kind of gasket creep relaxation performance prediction method, equipment and storage medium, the method comprises: S1, obtains the inner diameter and outer diameter of gasket in bolt flange joint;S2, according to gasket size and gasket initial sealing specific pressure, the normal pressure of gasket to be tested is calculated;S3, different temperature T and different initial sealing specific pressure, to gasket to be tested is carried out creep relaxation experiment, and test data is obtained and is pretreated;S4, the relationship between the initial sealing specific pressure of gasket at high temperature, temperature, time and gasket creep variable Δ (t) at high temperature is established;S5, the test data of same sealing specific pressure different temperature and same temperature different sealing specific pressure is fitted, and gasket creep relaxation performance characterization formula is obtained;S6, based on gasket creep relaxation performance characterization formula obtained in S5, the gasket creep relaxation performance at set temperature and set initial sealing specific pressure is predicted.Compared with prior art, the present application has the advantages of high gasket creep relaxation performance prediction accuracy.

Description

Technical Field

[0001] The present invention relates to the technical field of bolt flange joint gaskets, and in particular to a method, a device and a storage medium for predicting creep relaxation performance of gaskets. Background Art

[0002] Bolted flange joints are widely used today in various fields, including chemical engineering, petroleum, and aerospace, due to their safety, economy, ease of assembly and disassembly, and excellent sealing properties. Furthermore, public requirements for container and pipeline sealing are becoming increasingly stringent. During the operation of bolted flange joints, failures due to insufficient strength are rare; more often, failures are caused by leakage from the flange joint. This is especially true when the joint operates under high temperature and high pressure conditions. High temperatures not only accelerate the creep relaxation and aging of the gasket, reducing its elasticity, but also exacerbate deformation of the bolts and flange. During this process, because the sealing gasket is the most critical sealing element in the flange connection system, its creep relaxation failure is often the main cause of flange connection failure. Its mechanical and sealing properties directly affect the entire flange joint, making its creep relaxation performance particularly important for flange joints.

[0003] Although the influence of creep relaxation of gaskets on the load and leakage of flange joints has been recognized, creep relaxation of gaskets has not been considered in many current studies on flange joints. Moreover, most domestic and foreign studies on flange joints still use numerical simulation methods, and current related research often focuses on the creep relaxation and leakage rate of non-metallic gaskets and rubber gaskets. Summary of the Invention

[0004] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and provide a method, equipment and storage medium for predicting the creep relaxation performance of gaskets with high prediction accuracy. The method can predict the creep change of gaskets in bolted flange joints that are in high temperature conditions and have been in service for a long time, and provide a basis for engineering and technical personnel to perform secondary tightening of flange joints and thus control the leakage rate.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] According to a first aspect of the present invention, a method for predicting creep relaxation performance of a gasket is provided, the method comprising the following steps:

[0007] Step S1: Obtain the inner diameter D of the gasket in the bolted flange joint i and outer diameter D o ;

[0008] Step S2: Calculate the normal pressure F of the gasket to be tested based on the gasket size and the initial sealing pressure P of the gasket;

[0009] Step S3: performing creep relaxation experiments on the gasket to be tested at different temperatures T and different initial sealing pressure ratios P, and obtaining and preprocessing the test data;

[0010] Step S4, establishing a relationship between the gasket creep amount Δ(t) at high temperature and the initial sealing specific pressure P of the gasket at high temperature, temperature T, and time t;

[0011] Step S5, fitting the test data of the same sealing specific pressure but different temperatures, and the same temperature but different sealing specific pressures, to obtain a gasket creep relaxation performance characterization formula;

[0012] Step S6: Based on the gasket creep relaxation performance characterization formula obtained in step S5, predict the gasket creep relaxation performance at a set temperature and a set initial sealing pressure ratio.

[0013] Preferably, the expression of the gasket normal pressure F tested in step S2 is:

[0014]

[0015] Where D i 、D o are the inner diameter and outer diameter of the gasket respectively, and P is the initial sealing pressure of the gasket.

[0016] Preferably, the step S3 specifically comprises: performing a creep relaxation test on the gasket according to the EN13555 standard at different temperatures T and different initial sealing pressure ratios.

[0017] Preferably, the experimental time of the creep relaxation experiment is 16 hours.

[0018] Preferably, the pre-processing in step S3 specifically includes discarding the test data before loading to the specified sealing pressure ratio and the test data that starts to be unloaded after the test is completed.

[0019] Preferably, in step S4, the relationship between the gasket creep amount Δ(t) at high temperature and the initial sealing specific pressure P, temperature T, and time t of the gasket at high temperature is established, specifically:

[0020] Δ(t)=f(T,P,t)

[0021] Where Δ(t) is the amount of gasket creep at high temperature, f represents the functional relationship, and T, P, and t are temperature, initial sealing pressure, and time, respectively.

[0022] Preferably, the creep relaxation performance expression of the gasket in step S5 is specifically:

[0023]

[0024] In the formula, C1=a1lnT-b1, C2=a2lnT-b2, C3=a3-b3lnT, C4=a4+b4T, Wherein, a1-a5, b1-b5, n are undetermined parameters.

[0025] According to the second aspect of the present application, an electronic device is provided, comprising a memory and a processor, the memory has a computer program stored thereon, and the processor implements the method of any one of the aspects when executing the program.

[0026] According to the third aspect of the present application, a computer readable storage medium is provided, having a computer program stored thereon, the program is executed by a processor to implement the method of any one of the aspects.

[0027] Compared with the prior art, the present application has the following advantages:

[0028] 1) The present application provides a gasket creep relaxation performance prediction method, which can predict the creep amount change of the gasket in the bolt flange joint under high temperature working condition and long time service, so that the engineering and technical personnel can not only know the real-time gasket creep amount of the gasket during service, but also can obtain the real-time size of the bolt force by combining the gasket creep amount with the flange joint deformation coordination equation, thereby providing basis for the engineering and technical personnel to perform secondary tightening of the flange joint and further control the leakage rate.

[0029] 2) The calculation method of the present application is relatively simple, for a certain type of gasket, only some creep relaxation tests are needed to obtain the undetermined parameters, and then the gasket creep amount change rule under certain temperature and certain initial sealing specific pressure can be obtained according to the gasket creep relaxation performance characterization formula.

[0030] 3) The present application adopts the pretreatment method of discarding the test data before loading to the specified sealing specific pressure and starting unloading after the test is completed, thereby improving the effectiveness of the test data and the accuracy of subsequent fitting.

[0031] 4) The gasket creep relaxation performance characterization formula obtained by fitting according to the actual test data in the present application is more accurate. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 The flow chart of the method of the present application is shown in the figure;

[0033] Figure 2 The structure diagram of the metal graphite winding gasket is shown in the figure;

[0034] Figure 3 The test data and fitting curve obtained by the test of the metal graphite winding gasket under the same sealing specific pressure and different temperatures are shown in the figure;

[0035] Figure 4 The test data and fitting curves are obtained from the tests of metal graphite spiral wound gaskets at the same temperature and different sealing pressure ratios.

[0036] Figure 5 This is the prediction curve of gasket creep relaxation performance. DETAILED DESCRIPTION

[0037] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are 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 any creative efforts should fall within the scope of protection of the present invention.

[0038] Example

[0039] like Figure 1 As shown, this embodiment provides a method for predicting creep relaxation performance of a gasket, which includes the following steps:

[0040] Step S1: Obtain the inner diameter D of the gasket in the bolted flange joint i and outer diameter D o ;

[0041] Step S2: Calculate the normal pressure F of the gasket to be tested based on the gasket size and the initial sealing pressure P of the gasket. The expression is:

[0042] The expression of the gasket normal pressure F in the test is:

[0043]

[0044] Where D i 、D o are the inner diameter and outer diameter of the gasket respectively, and P is the initial sealing pressure of the gasket.

[0045] Step S3: performing creep relaxation experiments on the gasket to be tested at different temperatures T and different initial sealing pressure ratios P, and obtaining and preprocessing the test data;

[0046] Step S4, establishing a relationship between the gasket creep amount Δ(t) at high temperature and the initial sealing specific pressure P of the gasket at high temperature, temperature T, and time t;

[0047] Step S5, fitting the test data of the same sealing specific pressure but different temperatures, and the same temperature but different sealing specific pressures, to obtain a gasket creep relaxation performance characterization formula;

[0048] Step S6: Based on the gasket creep relaxation performance characterization formula obtained in step S5, predict the gasket creep relaxation performance at a set temperature and a set initial sealing pressure ratio.

[0049] Next, the creep relaxation performance prediction of metal-graphite spiral wound gaskets under high temperature conditions is introduced in detail. The specification of metal-graphite spiral wound gaskets is DN80. The specific implementation is as follows:

[0050] Get the specific inner and outer diameters D of the wound part of the metal graphite spiral wound gasket i 、D o ,like Figure 2 As shown;

[0051] The gasket normal pressure F required for the test is determined based on the gasket size and the required initial sealing pressure P of the gasket;

[0052] At different temperatures T and different initial sealing pressure ratios, creep relaxation tests were conducted on the gaskets according to the EN13555 standard for 16 hours. Two sets of tests were conducted in this example. The first set of tests was conducted under the following conditions: an initial sealing pressure ratio of 110 MPa, and temperatures of room temperature, 100°C, 200°C, 300°C, and 400°C. The second set of tests was conducted under the following conditions: a test temperature of 400°C, and initial sealing pressure ratios of 70 MPa, 110 MPa, and 120 MPa, respectively.

[0053] Process the data obtained from the test and discard the data before loading to the required sealing pressure ratio and the data when unloading begins after the test is completed;

[0054] The test data of the same sealing pressure ratio, different temperatures and the same temperature and different sealing pressure ratios are plotted into a graph, that is, the experimental data of the initial sealing pressure ratio of 110MPa, the temperatures of room temperature, 100℃, 200℃, 300℃, 400℃ and the test temperature of 400℃, the initial sealing pressure ratios of 70MPa, 110MPa and 120MPa are plotted into a graph, as shown in Figure 1. Figure 3 and Figure 4 Middle scatter plot part;

[0055] The relationship between the gasket creep amount Δ(t) at high temperature and the initial sealing pressure P, temperature T, and time t of the gasket at high temperature is established as follows:

[0056]

[0057] Where, C1 = a1lnT-b1, C2 = a2lnT-b2, C3 = a3-b3lnT, C4 = a4+b4T, Among them, a1~a5, b1~b5, and n are parameters to be determined.

[0058] Fit the curve graph, such as Figure 3 and Figure 4 In the curve graph part, the undetermined coefficients are obtained, and then the specific expression of the gasket creep amount is obtained;

[0059] After the previous step, the creep relaxation performance characterization formula of the gasket has been obtained, which can be used to predict the creep relaxation performance of the gasket under a certain temperature and a certain initial sealing pressure ratio. Figure 5 As shown in the figure, the top two curves are the creep relaxation performance prediction curves of metal graphite spiral wound gaskets at an initial specific pressure of 110 MPa and working temperatures of 500°C and 600°C.

[0060] The electronic device of the present invention includes a central processing unit (CPU), which can perform various appropriate actions and processes according to computer program instructions stored in a read-only memory (ROM) or loaded from a storage unit into a random access memory (RAM). In the RAM, various programs and data required for device operation can also be stored. The CPU, ROM, and RAM are connected to each other via a bus. An input / output (I / O) interface is also connected to the bus.

[0061] Many components in a device are connected to the I / O interface, including: input units, such as a keyboard and mouse; output units, such as various types of displays and speakers; storage units, such as magnetic disks and optical disks; and communication units, such as network cards, modems, and wireless communication transceivers. The communication unit allows the device to exchange information / data with other devices via computer networks such as the Internet and / or various telecommunication networks.

[0062] The processing unit performs the various methods and processes described above, such as methods S1 to S6. For example, in some embodiments, methods S1 to S6 may be implemented as a computer software program that is tangibly contained in a machine-readable medium, such as a storage unit. In some embodiments, part or all of the computer program may be loaded and / or installed onto the device via a ROM and / or a communication unit. When the computer program is loaded into the RAM and executed by the CPU, one or more steps of methods S1 to S6 described above may be performed. Alternatively, in other embodiments, the CPU may be configured to execute methods S1 to S6 by any other appropriate means (e.g., by means of firmware).

[0063] The functions described above herein may be performed, at least in part, by one or more hardware logic components. For example, and without limitation, exemplary types of hardware logic components that may be used include: field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chips (SOCs), load programmable logic devices (CPLDs), and the like.

[0064] The program code for implementing the method of the present invention can be written in any combination of one or more programming languages. Such program code can be provided to a processor or controller of a general-purpose computer, a special-purpose computer, or other programmable data processing device so that when the program code is executed by the processor or controller, the functions / operations specified in the flow chart and / or block diagram are implemented. The program code can be executed entirely on the machine, partially on the machine, as a stand-alone software package, partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0065] In the context of the present invention, machine-readable medium can be a tangible medium that can contain or store a program for use with an instruction execution system, device or equipment or used in combination with an instruction execution system, device or equipment. Machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. Machine-readable medium can include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared or semiconductor systems, devices or equipment, or any suitable combination of the foregoing. More specific examples of machine-readable storage media can include electrical connections based on one or more lines, portable computer disks, hard disks, random access memories (RAM), read-only memories (ROM), erasable programmable read-only memories (EPROM or flash memory), optical fibers, portable compact disk read-only memories (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0066] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and such modifications or substitutions are intended to be within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. A method for predicting creep relaxation performance of a gasket, characterized in that: The method comprises the following steps: Step S1: Obtain the inner diameter D of the gasket in the bolted flange joint i and outer diameter D o ; Step S2: Calculate the normal pressure F of the gasket to be tested based on the gasket size and the initial sealing pressure P of the gasket; Step S3: performing creep relaxation experiments on the gasket to be tested at different temperatures T and different initial sealing pressure ratios P, and obtaining and preprocessing the test data; Step S4: Establishing the creep of gasket at high temperature The relationship between the initial sealing pressure P of the gasket at high temperature, temperature T, and time t; Step S5: Fit the test data of the same sealing pressure ratio but different temperatures, and the same temperature but different sealing pressure ratios, to obtain a gasket creep relaxation performance characterization formula, specifically: Where, , , , , ; Among them, a1~a5, b1~b5, and n are parameters to be determined; Step S6: Based on the gasket creep relaxation performance characterization formula obtained in step S5, predict the gasket creep relaxation performance at a set temperature and a set initial sealing pressure ratio.

2. A gasket creep relaxation performance prediction method according to claim 1, characterized in that: The expression of the gasket normal pressure F tested in step S2 is: Where D i 、D o are the inner diameter and outer diameter of the gasket respectively, and P is the initial sealing pressure of the gasket.

3. A method for predicting creep relaxation performance of a gasket according to claim 1, characterized in that: The step S3 specifically includes: performing a creep relaxation test on the gasket according to the EN13555 standard at different temperatures T and different initial sealing pressure ratios.

4. A method for predicting creep relaxation performance of a gasket according to claim 3, characterized in that: The experimental time of the creep relaxation experiment is 16 hours.

5. A method for predicting creep relaxation performance of a gasket according to claim 1, characterized in that: The pre-processing in step S3 specifically includes discarding the test data before loading to the specified sealing pressure ratio and the test data that begins to be unloaded after the test is completed.

6. An electronic device comprising a memory and a processor, wherein a computer program is stored in the memory, wherein: When the processor executes the program, the method according to any one of claims 1 to 5 is implemented.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the method according to any one of claims 1 to 5 is implemented.

Images