A spherical tube sheet stress measurement experimental device and measurement method

Abstract

The present invention provides a spherical tube sheet stress measurement experimental device and a measurement method, the device includes a spherical tube sheet model, a device body, external pipelines and a liquid storage tank; the device body includes a base, an outer cylinder, an upper head, and a strain gauge. The spherical tube sheet model includes an upper tube sheet, a lower tube sheet, a heat exchange tube, a support tube and a strain gauge group. The present invention simplifies the large-scale spherical tube sheet structure in the reactor into a small-scale model based on similarity theory and places it in the experimental device, avoiding dependence on the equipment prototype, and at the same time adopts an internal compensation method to compensate for the additional deformation of the strain gauge caused by the pressure effect, so that the measurement result is more accurate.

Description

Technical Field

[0001] The invention relates to the technical field of stress measurement, and in particular to a spherical tube sheet stress measurement experimental device and a measurement method. Background Art

[0002] The tube sheet is one of the important components of the shell-and-tube heat exchanger and reactor. It connects the heat exchange tube bundle and separates the shell-and-tube space. As an important pressure-bearing component in the equipment, understanding the stress of the tube sheet and ensuring its structural strength is one of the key issues that need to be considered to ensure the safety of the equipment.

[0003] Spherical tube sheets are a new type of tube sheet used in radial flow reactors. While meeting the internal structural requirements of radial flow reactors, they have the advantages of a large number of tubes and good stress conditions. At present, researchers are conducting research on theoretical methods for stress analysis of spherical tube sheets. There is no mature theoretical method for stress analysis of spherical tube sheets. Finite element numerical simulation methods are used in engineering to verify the structural strength of tube sheets, but the mechanical model has been simplified to a certain extent during numerical simulation, so the accuracy of the numerical simulation method and simulation results still needs to be verified. Directly measuring the stress of spherical tube sheets through experiments is an effective way to verify the reliability of numerical simulation and theoretical calculation methods and results.

[0004] At present, there are two main experimental methods for measuring tube sheet stress. The first is the electrical measurement method. This method refers to directly placing the resistance strain gauge at the position to be measured on the tube sheet. After the strain gauge is sealed and insulated, it is connected to the resistance strain gauge through a wire. When the measured tube sheet is subjected to load, it deforms, and the resistance wire in the resistance strain gauge deforms accordingly, causing resistance changes. Through the resistance strain gauge, the strain value of the measured area of ​​the tube sheet can be read, and then the stress is obtained through the generalized Hooke's law. The second method is the photoelastic method. This method refers to using transparent plastic with birefringence properties to make a model with a geometric shape similar to the measured tube sheet structure, simulating the actual tube sheet loading, placing the loaded plastic tube sheet model in a polarized light field, and obtaining an interference fringe pattern. According to the photoelastic principle and the interference fringe pattern, the magnitude and direction of the stress at the corresponding position on the plastic tube sheet model can be calculated, and then the stress at the corresponding position on the prototype tube sheet can be converted according to the similarity criterion determined when making the model. Compared with the two, the electrical measurement method is simple, convenient and low-cost, but it needs to be measured in the prototype of the device under test. Usually, the prototype of the device has a large size and a complex internal structure. The process of disassembling, installing the equipment, and arranging the strain gauges is cumbersome, which greatly limits the application of this method. The photoelastic method is based on the similarity theory and analyzes by making a similar model of the prototype structure, which avoids the need for the device prototype and is more advantageous. However, the photoelastic model can only be used once and cannot meet the needs of repeated experiments. Therefore, for the stress measurement of spherical tube sheets, the advantages of both can be combined to develop a universal stress measurement experimental device to provide an experimental basis for the theoretical calculation and numerical simulation of its stress. Summary of the invention

[0005] The technical problem to be solved by the present invention is: in order to overcome the shortcomings of the prior art, the present invention provides a spherical tube sheet stress measurement experimental device and a measurement method, which is set up based on similarity theory and can conveniently and accurately measure the actual stress condition of the spherical tube sheet through experiments.

[0006] The technical solution adopted by the present invention to solve its technical problems is: a spherical tube sheet stress measurement experimental device, including a spherical tube sheet model, a device body, an external pipeline and a liquid storage tank; the device body includes a base, an outer cylinder, an upper head, and a strain gauge, the outer cylinder is fixed on the upper surface of the base, and the upper head is fixed on the top of the outer cylinder, the spherical tube sheet model is arranged in a chamber formed by the base, the outer cylinder and the upper head, and the chamber is divided into a tube-side space and a shell-side space, wherein the tube-side space is inside the spherical tube sheet model, and the shell-side space is between the spherical tube sheet model and the outer cylinder; the strain gauge is connected to the strain gauge group through a wire; the spherical tube sheet model includes an upper tube sheet, a lower tube sheet, a heat exchange tube, a support tube and a strain gauge group, the lower tube sheet is fixed The heat exchange tube and the support tube are connected between the upper tube plate and the lower tube plate. The lower tube plate forms a pipe layout circle corresponding to the connection position of the heat exchange tube and the support tube. The strain gauge group includes a plurality of strain gauges, which are respectively arranged between the pipe layout circles on the inner surface and the outer surface of the lower tube plate. The external pipeline includes a tube-side pressurizing pipeline, a shell-side pressurizing pipeline and a drainage pipeline. The liquid storage tank is connected to the tube-side space through the tube-side pressurizing pipeline, and the liquid storage tank is connected to the shell-side space through the shell-side pressurizing pipeline. The tube-side pressurizing pipeline and the shell-side pressurizing pipeline are also connected with a drainage pipeline. The front end of the drainage pipeline is respectively connected to the tube-side pressurizing pipeline and the shell-side pressurizing pipeline, and the rear end is connected to the liquid storage tank.

[0007] Preferably, the strain measurement adopts the internal compensation method, and the outer surface strain rosettes are attached between each layer of pipe arrangement circles on the outer surface of the lower tube plate, and the inner surface strain rosettes are attached between each layer of pipe arrangement circles on the inner surface of the lower tube plate. The lower tube plate corresponds to the outer side of the pipe arrangement circle, and the outer surface compensation strain rosettes are attached along the outer surface strain rosettes; the lower tube plate corresponds to the outer side of the pipe arrangement circle, and the inner surface compensation strain rosettes are attached along the inner surface strain rosettes. The inner and outer surface compensation strain rosettes are only attached at one end, and can be freely extended and retracted under pressure to measure the additional deformation of the strain rosettes due to the pressure effect.

[0008] Preferably, the tube-side pressurizing pipeline is provided with a manual pressure test pump and a check valve in sequence along the pipeline from the liquid storage tank to the tube-side space; the shell-side pressurizing pipeline is provided with a manual pressure test pump and a check valve in sequence along the pipeline from the liquid storage tank to the shell-side space; the tube-side pressurizing pipeline is connected to a drain valve on the pipeline at the rear end of the check valve, and the shell-side pressurizing pipeline is also connected to a drain valve on the pipeline at the rear end of the check valve, and the above-mentioned drain valve is connected to the drain pipeline.

[0009] In order to exhaust the air in the device before applying pressure, the upper head is connected to the tube side space and the shell side space with a drain valve. In order to observe the pressure in the device in real time and ensure the safety of the device, the upper head is also connected to the tube side space and the shell side space through the outlet valve. The pressure safety device is a pressure gauge and a safety valve connected in parallel after the outlet valve.

[0010] A spherical tube sheet stress measurement method, using the above-mentioned spherical tube sheet stress measurement experimental device, the measurement method is as follows:

[0011] (1) Determine the similarity criterion between the spherical tube sheet model and the measurement prototype through dimensional analysis, make the spherical tube sheet model, connect the strain gauge group and the strain gauge through wires, and assemble the entire experimental device;

[0012] (2) Record the actual size of the spherical tube sheet model and the detailed pasting position of the strain gauge group, and record the corresponding relationship between each reading point on the strain gauge and the actual strain gauge;

[0013] (3) According to the sensitivity coefficient of the strain gauge used, adjust the sensitivity coefficient of the strain gauge to be the same as the sensitivity coefficient of the strain gauge;

[0014] (4) Adjust the strain gauge point by point so that the strain reading at each measuring point is close to zero;

[0015] (5) Use a manual pressure test pump to deliver liquid to the tube side space and shell side space respectively. When liquid flows out of the pipeline behind the drain valve, close the corresponding drain valve. Continue to use the manual pressure test pump to load pressure to the tube side space and shell side space and observe the pressure gauge reading until the pressure in the device reaches the target pressure;

[0016] (6) Record the strain value of each measuring point through the strain gauge;

[0017] (7) Pressurize the tube-side space and the shell-side space to the next target pressure and record the strain value at each measuring point;

[0018] (8) After the test, open the drain valve to release the pressure in the device and turn off the power supply of the strain gauge.

[0019] The beneficial effects of the present invention are as follows: the present invention simplifies the large-sized spherical tube sheet structure in the reactor into a small-sized model based on similarity theory and places it in an experimental device, thereby avoiding dependence on the equipment prototype, and at the same time adopts an internal compensation method to compensate for the additional deformation of the strain gauge caused by the pressure effect, so that the measurement result is more accurate.

[0020] Compared with the measurement of tube sheet stress by photoelastic method, the spherical tube sheet model of the present invention can be made of the same material as the prototype structure, which simplifies the variables in the dimensional analysis process, avoids the errors caused by using different materials in similar calculations, and ignores the influence of non-critical structures in the prototype equipment, thereby improving the simplicity of model making. In addition, multiple repeated experiments can be performed on different tube shell pressure combinations, which improves the accuracy of measurement and is more economical. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0022] Figure 1 It is a structural schematic diagram of the present invention.

[0023] Figure 2 It is a side view of the base of the present invention.

[0024] Figure 3 It is a layout diagram of strain gauges on the outer surface of the lower tube sheet of the spherical tube sheet model of the present invention.

[0025] Figure 4 It is a layout diagram of strain gauges on the inner surface of the lower tube sheet of the spherical tube sheet model of the present invention.

[0026] In the figure, 1, strain gauge 2, base 2-1, pressurized pipeline pipe 2-2, wire pressure-resistant joint 3, outer cylinder 4, spherical tube sheet model 4-1, upper tube sheet 4-2, heat exchange tube 4-3, support tube 4-4, lower tube sheet 4-5, strain gauge group 4-5-1, outer surface strain rosette 4-5-2, outer surface compensation strain rosette 4-5-3, inner surface strain rosette 4-5-4, inner surface compensation strain rosette 4-6, upper tube sheet cylinder 4-7, lower tube sheet cylinder 5, upper head 5-1, drain valve 5-2, pressure gauge 5-3, safety valve 6, liquid storage tank 7-1, manual pressure test pump 7-2, check valve 7-3, tube side pressurized pipeline 7-4, shell side pressurized pipeline 8, drain pipeline 8-1, drain valve DETAILED DESCRIPTION

[0027] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams that only illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention, and directions and references (e.g., up, down, left, right, etc.) may only be used to help describe the features in the drawings. Therefore, the following specific embodiments are not to be taken in a limiting sense, and the scope of the subject matter claimed is limited only by the attached claims and their equivalents.

[0028] like Figures 1 to 4The spherical tube sheet stress measurement experimental device shown includes a spherical tube sheet model 4, a device body, an external pipeline and a liquid storage tank 6. The spherical tube sheet model 4 is obtained by reducing the spherical tube sheet prototype structure in the reactor where stress needs to be measured according to the similarity theory. The device body includes a base 2, an outer cylinder 3, an upper head 5 and a strain gauge 1.

[0029] The base 2 is provided with a pressurized pipeline pipe 2-1 for connecting an external pressurized pipeline, and is also provided with a screw hole for installing the outer cylinder 3 and the spherical tube sheet model 4, and is also provided with a pressure-resistant joint that can connect the strain gauge wire to the strain gauge 1. The outer cylinder 3 is fixed on the upper surface of the base 2, and the upper head 5 is fixed on the top of the outer cylinder 3. The spherical tube sheet model 4 is arranged in a chamber formed by the base 2, the outer cylinder 3 and the upper head 5, and the chamber is divided into a tube-side space and a shell-side space, wherein the tube-side space is inside the spherical tube sheet model 4, and the shell-side space is between the spherical tube sheet model 4 and the outer cylinder 3.

[0030] The external pipeline includes a pressurizing pipeline and a drain pipeline 8. The pressurizing pipeline includes a tube-side pressurizing pipeline 7-3 connected to the tube-side space and a shell-side pressurizing pipeline 7-4 connected to the shell-side space. A manual pressure test pump 7-1 and a check valve 7-2 are respectively provided on the two pressurizing pipelines. The pressurizing pipeline starts from the bottom of the liquid storage tank 6 and ends at the base 2 of the device body. The base 2 is provided with a pressurizing pipeline pipe 2-1 and a wire pressure-resistant joint 2-2. The drain pipeline 8 includes a tube-side drain pipeline 8 connected to the tube-side pressurizing pipeline 7-3 and a shell-side drain pipeline 8 connected to the shell-side pressurizing pipeline 7-4. The nodes where the two drain pipelines 8 are connected to the pressurizing pipeline are respectively located after the check valve 7-2 of the corresponding pressurizing pipeline, and a drain valve 8-1 is provided at the connection node. The tube-side drain pipeline 8 and the shell-side pressurizing pipeline 7-4 are connected to the device through the pressurizing pipeline pipe 2-1.

[0031] In order to observe the pressure in the device in real time and ensure the safety of the device, the upper head 5 is provided with a parallel pressure gauge 5-2 and a safety valve 5-3 respectively connected to the tube side space and the shell side space. At the same time, in order to exhaust the air in the device before loading the pressure, the upper head 5 is also provided with an exhaust valve 5-1 respectively connected to the tube side space and the shell side space.

[0032] The heat exchange tube 4-2 and the support tube 4-3 are connected between the upper tube sheet 4-1 and the lower tube sheet 4-4, and the lower tube sheet 4-4 forms a tube circle corresponding to the connection position of the heat exchange tube 4-2 and the support tube 4-3. The strain measurement adopts the internal compensation method, and strain rosettes that can measure two-way strain are attached between each layer of tube circles on the inner and outer surfaces of the lower tube sheet 4-4 of the spherical tube sheet model 4. That is, an outer surface strain rosette 4-5-1 is attached between each layer of tube circles on the outer surface of the lower tube sheet 4-4, and an inner surface strain rosette 4-5-3 is attached between each layer of tube circles on the inner surface of the lower tube sheet 4-4. In addition, the inner and outer surfaces are also separately provided with compensation strain gauges with only one end attached, which are used to measure the additional deformation of the strain gauge due to the pressure effect. That is, the lower tube plate 4-4 corresponds to the outside of the tube circle, and the outer surface compensation strain rosette 4-5-2 is attached to the outer surface strain rosette 4-5-1, and the lower tube plate 4-4 corresponds to the outside of the tube circle, and the inner surface compensation strain rosette 4-5-4 is attached to the inner surface strain rosette 4-5-3. The strain gauge group 4-5 is connected to the wire, and the wire is connected to the device through the wire pressure-resistant joint 2-2 and connected to the strain gauge 1.

[0033] A manual pressure test pump 7-1 and a check valve 7-2 are provided in sequence on the pipeline from the liquid storage tank 6 to the pipeline space of the tube side pressurizing pipeline 7-3; a manual pressure test pump 7-1 and a check valve 7-2 are provided in sequence on the pipeline from the liquid storage tank 6 to the shell side pressurizing pipeline 7-4; a drain valve 8-1 is connected to the pipeline at the rear end of the check valve 7-2 corresponding to the tube side pressurizing pipeline 7-3, and a drain valve 8-1 is also connected to the pipeline at the rear end of the check valve 7-2 corresponding to the shell side pressurizing pipeline 7-4, and the above-mentioned drain valve 8-1 is connected to the drain pipeline 8. The liquid storage tank 6 is a non-sealed structure, which is arranged at a lower position relative to the device body. After opening the drain valve 8-1 to unload the pressure in the device and then opening the emptying valve 5-1, the liquid in the device body will flow back to the liquid storage tank 6 along the drain pipeline 8 due to gravity. In order to prevent the strain measuring element from short-circuiting and prevent the device from corroding, the medium in the liquid storage tank 6 uses square shed oil as the pressurizing medium.

[0034] In the process of assembling the device, taking the spherical tube sheet and the heat exchange tube 4-2 bent toward the center in a radial reactor as the tube sheet structure prototype to be tested, the stress at a certain point on the prototype can be expressed as:

[0035]

[0036] Where σ represents the stress at that point; D represents the outer diameter of the tube sheet; δ D represents the thickness of the tube sheet; d represents the outer diameter of the heat exchange tube 4-2; δ d Indicates the thickness of the heat exchange tube 4-2; p i Indicates the pipe pressure; p o represents the shell pressure; L represents the length of the outer cylinder 3; E represents the elastic modulus of the material; υ represents the Poisson's ratio of the material; α1 represents the latitudinal angle of the point on the spherical surface; α2 represents the longitudinal angle of the point on the spherical surface.

[0037] After the spherical tube sheet model 4 is reduced according to the similarity criterion obtained from the dimensional analysis, its stress is measured using the electrical measurement method, avoiding the dependence on the equipment prototype, simplifying the measurement steps and experimental costs while meeting the needs of repeated experiments. At the same time, when simplifying the spherical tube sheet structure through similarity theory, the influence of other accessories on the prototype reactor is ignored, and only the components related to the spherical tube sheet stress, including the upper and lower spherical tube sheets, heat exchange tubes 4-2, support tubes 4-3, and part of the cylinder connected to the upper and lower tube sheets 4-4 are simplified, which improves the simplicity of model making.

[0038] The similarity criterion between the spherical tube sheet model 4 and the prototype can be determined by the above formula after dimensional analysis. Combined with the assembly requirements of the experimental device, the spherical tube sheet model 4 in this embodiment can be obtained, including an upper tube sheet 4-1, a lower tube sheet 4-4, a heat exchange tube 4-2, a support tube 4-3, a strain gauge group 4-5 attached to the inner and outer surfaces of the lower tube sheet 4-4, and upper and lower tube sheet cylinders 4-7; the strain gauge group 4-5 is composed of a plurality of outer surface strain rosettes 4-5-1, outer surface compensation strain rosettes 4-5-2, inner surface strain rosettes 4-5-3, and inner surface compensation strain rosettes 4-5-4 arranged between the inner and outer surface pipe distribution circles of the lower tube sheet 4-4.

[0039] After the spherical tube sheet model 4 is obtained, it is installed on the base 2, and the strain gauge group 4-5 and the strain gauge 1 arranged on the inner and outer surfaces of the tube sheet are connected to the corresponding pressure-resistant joints on the base 2 through wires. After the spherical tube sheet model 4 is installed, the outer cylinder 3 is installed on the base 2, and the upper head 5 is installed on the outer cylinder 3 and connected to the upper tube sheet cylinder 4-6 of the spherical tube sheet model 4. After the device body is installed, the pressurized pipeline is connected to the device body through the corresponding pipe on the base 2.

[0040] After the device is assembled, the tube sheet stress is measured by the following measurement method:

[0041] (1) Record the actual size of the spherical tube sheet model 4 and the detailed pasting positions of the strain gauge groups 4-5;

[0042] (2) Recording the corresponding relationship between each reading point on the strain gauge 1 and the actual strain gauge;

[0043] (3) According to the sensitivity coefficient of the strain gauge used, adjust the sensitivity coefficient of strain gauge 1 to be the same as the sensitivity coefficient of the strain gauge;

[0044] (4) Adjust the strain gauge 1 point by point so that the strain reading at each measuring point is close to zero;

[0045] (5) Use the manual pressure test pump 7-1 to deliver liquid to the tube side space and shell side space of the device respectively. When liquid flows out of the pipeline behind the drain valve 5-1, close the corresponding drain valve 5-1. Continue to use the manual pressure test pump 7-1 to add pressure to the device and observe the reading of the pressure gauge 5-2 until the pressure in the device reaches the target pressure;

[0046] (6) Record the strain values ​​of the outer surface strain rosette 4-5-1, the inner surface strain rosette 4-5-3, and the strain values ​​of the outer surface compensation strain rosette 4-5-2 and the inner surface compensation strain rosette 4-5-4 at each measuring point through the strain gauge 1;

[0047] (7) Pressurize the tube side space and the shell side space to the next target pressure respectively and record the strain values ​​of the outer surface strain rosette 4-5-1, the inner surface strain rosette 4-5-3, and the strain values ​​of the outer surface compensation strain rosette 4-5-2 and the inner surface compensation strain rosette 4-5-4 at each measuring point;

[0048] (8) After the test, open the drain valve 8-1 to release the pressure in the device and turn off the power supply of the strain gauge 1;

[0049] (9) The strain at each measuring point is subtracted from the corresponding compensation strain to obtain the true strain at each measuring point. The stress is calculated from the true strain, and then the stress at the corresponding position on the equipment prototype is determined by the similarity criterion.

[0050] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A spherical tube sheet stress measurement experimental device, characterized in that: It includes a spherical tube sheet model (4), a device body, external pipelines and a liquid storage tank (6); The device body comprises a base (2), an outer cylinder (3), an upper head (5), and a strain gauge (1); the outer cylinder (3) is fixed to the upper surface of the base (2); the upper head (5) is fixed to the top of the outer cylinder (3); the spherical tube sheet model (4) is arranged in a chamber formed by the base (2), the outer cylinder (3), and the upper head (5), and the chamber is divided into a tube-side space and a shell-side space, wherein the tube-side space is inside the spherical tube sheet model (4), and the shell-side space is between the spherical tube sheet model (4) and the outer cylinder (3); The strain gauge (1) is connected to the strain gauge group (4-5) via a wire. The spherical tube sheet model (4) comprises an upper tube sheet (4-1), a lower tube sheet (4-4), a heat exchange tube (4-2), a support tube (4-3) and a strain gauge group (4-5); the lower tube sheet (4-4) is fixed to the upper surface of the base (2); the upper tube sheet (4-1) is fixed to the lower surface of the upper head (5); the heat exchange tube (4-2) and the support tube (4-3) are connected between the upper tube sheet (4-1) and the lower tube sheet (4-4); the lower tube sheet (4-4) forms a tube layout circle corresponding to the connection position of the heat exchange tube (4-2) and the support tube (4-3); the strain gauge group (4-5) comprises a plurality of strain gauges, and the strain gauges are respectively arranged between the tube layout circles on the inner surface and the outer surface of the lower tube sheet (4-4); The external pipeline comprises a tube-side pressurizing pipeline (7-3), a shell-side pressurizing pipeline (7-4) and a liquid discharge pipeline (8); the liquid storage tank (6) is connected to the tube-side space via the tube-side pressurizing pipeline (7-3); the liquid storage tank (6) is connected to the shell-side space via the shell-side pressurizing pipeline (7-4); a liquid discharge pipeline (8) is also connected to the tube-side pressurizing pipeline (7-3) and the shell-side pressurizing pipeline (7-4); the front end of the liquid discharge pipeline (8) is respectively connected to the tube-side pressurizing pipeline (7-3) and the shell-side pressurizing pipeline (7-4); and the rear end is connected to the liquid storage tank (6); An outer surface strain rosette (4-5-1) is attached between each layer of tube arrangement circles on the outer surface of the lower tube plate (4-4); an outer surface compensation strain rosette (4-5-2) is attached to the lower tube plate (4-4) corresponding to the outer side of the tube arrangement circle and extending from the outer surface strain rosette (4-5-1); an inner surface strain rosette (4-5-3) is attached between each layer of tube arrangement circles on the inner surface of the lower tube plate (4-4); an inner surface compensation strain rosette (4-5-4) is attached to the lower tube plate (4-4) corresponding to the outer side of the tube arrangement circle and extending from the inner surface strain rosette (4-5-3); The tube-side pressurizing pipeline (7-3) is provided with a manual pressure test pump (7-1) and a check valve (7-2) in sequence along the pipeline from the liquid storage tank (6) to the tube-side space; the shell-side pressurizing pipeline (7-4) is provided with a manual pressure test pump (7-1) and a check valve (7-2) in sequence along the pipeline from the liquid storage tank (6) to the shell-side space; a drain valve (8-1) is connected to the pipeline at the rear end of the check valve (7-2) of the tube-side pressurizing pipeline (7-3), and a drain valve (8-1) is also connected to the pipeline at the rear end of the check valve (7-2) of the shell-side pressurizing pipeline (7-4); the drain valve (8-1) is connected to the drain pipeline (8); The upper head (5) is connected to drain valves (5-1) corresponding to the tube-side space and the shell-side space respectively; the upper head (5) is also connected to pressure safety devices corresponding to the tube-side space and the shell-side space respectively through the outlet valves, and the pressure safety devices are a pressure gauge (5-2) and a safety valve (5-3) arranged in parallel behind the outlet valve.

2. A method for measuring stress of a spherical tube sheet, characterized in that: Using the spherical tube sheet stress measurement experimental device as claimed in claim 1, the measurement method is as follows: (1) Determine the similarity criterion between the spherical tube sheet model (4) and the measurement prototype through dimensional analysis, make the spherical tube sheet model (4), connect the strain gauge group (4-5) and the strain gauge (1) through wires, and assemble the entire experimental device; (2) Record the actual size of the spherical tube sheet model (4) and the detailed pasting position of the strain gauge group (4-5), and record the corresponding relationship between each reading point on the strain gauge (1) and the actual strain gauge; (3) According to the sensitivity coefficient of the strain gauge used, adjust the sensitivity coefficient of the strain gauge (1) to be the same as the sensitivity coefficient of the strain gauge; (4) Adjust the strain gauge (1) point by point so that the strain reading at each measuring point is close to zero; (5) Use the manual pressure test pump (7-1) to deliver liquid to the tube side space and the shell side space respectively. When liquid flows out of the pipeline behind the drain valve (5-1), close the corresponding drain valve (5-1). Continue to use the manual pressure test pump (7-1) to add pressure to the tube side space and the shell side space and observe the reading of the pressure gauge (5-2) until the pressure in the device reaches the target pressure. (6) Record the strain value of each measuring point through the strain gauge (1); (7) Pressurize the tube-side space and shell-side space to the next target pressure and record the strain value at each measuring point; (8) When the test is finished, open the drain valve (8-1) to release the pressure in the device and turn off the power supply of the strain gauge (1).

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