Performance testing device and method for pressure vessel at different service temperatures

Abstract

The application discloses a performance testing device and method for pressure containers under different service temperatures and relates to the field of material performance testing, which comprises an axial pressure applying mechanism and a radial pressure applying mechanism. The simulation test piece is made into an annular structure for simulating the actual shape of the pressure container. A partition plate is fixed in the simulation test piece, which divides the simulation test piece into a steam cavity above and a heating cavity below for simulating the actual working state of the pressure container. A flame gun is arranged on one side of the simulation test piece. The axial pressure applying mechanism comprises a base pedestal and a tension-compression frame. A tension-compression beam is slidably arranged on the tension-compression frame. The two ends of the simulation test piece are respectively fastened on the tension-compression beam and the base pedestal. The radial pressure applying mechanism comprises a plurality of base columns. The base columns are arranged around the circumference of the lower fastening flange. A plurality of radial pressure shafts are slidably arranged on the base columns along the height direction of the base columns, so that the stress state of the material is highly consistent with the real service state of the steam boiler, and the performance testing accuracy of the material is higher.

Description

Technical Field

[0001] This invention relates to the field of material performance testing, specifically to a device and method for testing the performance of pressure vessels at different service temperatures. Background Technology

[0002] Pressure vessels, as core pressure-bearing equipment in the energy and chemical industries, operate in harsh environments with multiple characteristics. Steam boilers, in particular, must withstand wide temperature fluctuations ranging from -45℃ to 600℃, high pressure gradients from 0.1 to 30 MPa, and corrosion from complex media containing corrosive ions such as Cl⁻ and SO₄²⁻. When manufacturing steam boilers, appropriate materials must be selected based on the boiler's operating environment. Before manufacturing, material performance testing is necessary to determine if the material meets the service conditions of the steam boiler. Currently, the testing of steam boiler materials has the following shortcomings: Firstly, the specimen structure is out of sync with reality: existing tests mostly use plate-shaped, CT-shaped, or round bar specimens, without adopting annular structures and flange connection designs. This makes it impossible to reproduce the annular stress characteristics of pressure vessels and the stress concentration effect at flange connections, and ignores the influence of the core structure of "annular sealing + flange fixing" on the mechanical properties of actual equipment, resulting in stress transmission paths that do not match the actual working conditions.

[0003] Secondly, the operating condition simulation lacks a zoned design: the furnace side is directly subjected to the combustion flame, and the local temperature can reach over 1000℃, while the steam side temperature changes dynamically with the working pressure (0.1~30MPa corresponds to a saturation temperature of 99℃~345℃), forming a significant double-sided temperature difference stress. Without a separate structure for the steam chamber and the heating chamber, it is impossible to simulate the actual working process of the boiler "combustion heating → water-steam conversion → steam pressurization", and it is difficult to reproduce the coupled effect of the change in the state of the medium during steam generation on material corrosion and fatigue.

[0004] Thirdly, the impact of multiple stress constraints on boiler performance is not considered: the boiler is subjected to axial constraint thrust from the supports (0-100MPa), and the header is subjected to radial compression from the water-cooled wall tubes (0-80MPa). This is compounded by the fluctuation in medium flow velocity caused by steam-water circulation (0.5-3m / s), forming a triple coupling of "thermal stress + pressure stress + erosion stress". Currently, when testing materials, only the impact of temperature on boiler service performance is considered, without taking into account the actual operating environment of the steam boiler. This results in low accuracy of actual test results, affecting the judgment of material performance and consequently affecting the subsequent service performance of the steam boiler.

[0005] Fourth, the impact of uneven heating and steam liquefaction on boiler performance was ignored: In actual operation, boilers will face long-term low-load operation, which will lead to uneven combustion in the furnace, local low temperature of the heating surface, steam liquefaction, and condensation of acidic media (such as H2SO4, HCl), which will accelerate corrosion; long-term overload operation (exceeding the rated load by 10%) will cause the heat flux density of the heating surface to be too high, the metal wall temperature to exceed the standard, and at the same time increase the steam-water circulation resistance, aggravating wear and fatigue. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a performance testing device and method for pressure vessels at different service temperatures, thereby addressing the deficiencies of the prior art.

[0007] The objective of this invention is achieved through the following technical solution: a performance testing device for a pressure vessel under different service temperatures, comprising an axial pressure mechanism, a radial pressure mechanism, and a simulated specimen. The simulated specimen is manufactured in a ring structure, with an upper mounting flange and a lower mounting flange fixed to its top and bottom, respectively, to simulate the actual shape of the pressure vessel. A partition is fixed inside the simulated specimen, dividing it into an upper steam chamber and a lower heating chamber to simulate the actual working state of the pressure vessel. A flame gun is provided on one side of the simulated specimen, and a heating opening communicating with the heating chamber is provided on the side wall of the simulated specimen. The flamethrower's nozzle extends into the heating chamber through a heating opening. A flow control valve is connected to the upper mounting flange via an exhaust pipe. A pressure gauge is installed on the upper mounting flange. The axial pressure mechanism includes a base and a tension / pressure frame. A tension / pressure beam is slidably mounted on the tension / pressure frame. An upper tooling flange is mounted on the tension / pressure beam. A lower tooling flange is fixed on the base. The radial pressure mechanism includes multiple base columns arranged around the circumference of the lower tooling flange. Multiple radial pressure shafts are slidably mounted on each base column along its height direction. Each radial pressure shaft has a degree of freedom to move radially along the lower tooling flange.

[0008] Furthermore, a power mechanism is provided at the end of the foundation column away from the lower tooling flange. The power mechanism includes a hydraulic cylinder and a power plate. The cylinder body of the hydraulic cylinder is fixed on the foundation column, the telescopic shaft of the hydraulic cylinder is connected to the power plate, and the radial pressure shaft is located on the moving path of the power plate.

[0009] Furthermore, the radial pressure shaft includes a primary sliding shaft and a secondary sliding shaft. The foundation column has a through hole for the primary sliding shaft to pass through. The end of the primary sliding shaft near the power plate has a mounting hole. One end of the secondary sliding shaft is slidably fitted into the mounting hole. A primary spring is installed in the mounting hole. The two ends of the primary spring are respectively connected to the primary sliding shaft and the secondary sliding shaft. A spring disc is fixedly sleeved on the primary sliding shaft. A secondary spring is sleeved on the primary sliding shaft. The two ends of the secondary spring are respectively connected to the foundation column and the spring disc. The elastic modulus of the secondary spring is greater than that of the primary spring.

[0010] Furthermore, the inner wall of the primary sliding shaft has two symmetrically formed mating grooves, and slots are formed on both sides of the secondary sliding shaft. A mating block is slidably adapted in the mating groove, and the mating block can be partially inserted into the slot.

[0011] Furthermore, the primary sliding shaft is provided with a docking cavity, and the docking cavity and the docking groove are staggered along the height direction of the foundation column. The cross-sectional shape of the docking cavity is C-shaped, and the two ends of the docking cavity are respectively connected to the two docking grooves. A C-shaped pressure block is provided in the docking cavity. The end face of the docking block near the C-shaped pressure block is provided with an inclined surface. The two ends of the C-shaped pressure block respectively contact the inclined surfaces of the two docking blocks. A locking screw is threaded onto the primary sliding shaft, and the tail of the locking screw penetrates into the docking cavity and contacts the C-shaped pressure block.

[0012] Furthermore, it also includes a flaw detection and testing mechanism, which includes a rotating ring, a flaw detection frame, an axial slide, and an ultrasonic phased array flaw detector. The rotating ring is rotatably mounted on the foundation base, the flaw detection frame is fixed on the rotating ring, the axial slide is disposed on the flaw detection frame, the axial slide has the degree of freedom to move axially along the lower tooling flange, and the ultrasonic phased array flaw detector is mounted on the axial slide and is located between two adjacent foundation columns.

[0013] Furthermore, a lead screw is rotatably mounted on the flaw detection frame, a lead screw slider is threaded onto the lead screw, an axial slide block is mounted on the lead screw slider, a first motor is mounted on the flaw detection frame, the output shaft of the first motor is connected to the lead screw via a coupling, a large gear ring is mounted on the rotating ring, a second motor is mounted on the base, the output shaft of the second motor is connected to a drive gear, and the drive gear meshes with the large gear ring.

[0014] Furthermore, a flame control mechanism is provided inside the heating chamber. The flame control mechanism includes a fixed flame plate and a fan-shaped block. An installation shaft is fixed to the bottom of the fixed flame plate, and the installation shaft is fixedly connected to the simulated test piece. A circular flame cavity is provided inside the fixed flame plate. Several flame holes communicating with the circular flame cavity are opened on the top of the fixed flame plate. An opening for the flame tube to pass through is opened on the side wall of the fixed flame plate. The fan-shaped block is rotatably installed on the top of the fixed flame plate. Several flame passage holes are opened through the fan-shaped block. By rotating the fan-shaped block, the fan-shaped block can block part of the flame holes, or the flame passage holes of the fan-shaped block can communicate with the flame holes.

[0015] Furthermore, the upper tooling flange has a through-hole for clearance, the exhaust pipe passes through the clearance, and the upper mounting flange is connected to a water inlet for injecting boiler water into the simulated specimen.

[0016] A method for testing the performance of a pressure vessel under different service temperatures, using the aforementioned pressure vessel performance testing device under different service temperatures, includes the following steps: S1. Fabrication of a simulated test specimen: The material to be tested is scaled down proportionally to the size of the actual pressure vessel, so that a steam chamber and a heating chamber are formed inside the simulated test specimen. The steam chamber is used to simulate the steam environment of the pressure vessel, and the heating chamber is used to simulate the temperature environment of the pressure vessel. S2, Tooling Simulation Specimen: The upper mounting flange of the simulation specimen is connected to the upper tooling flange, and the lower mounting flange of the simulation specimen is connected to the lower tooling flange. S3. Simulate the working environment of a pressure vessel for testing: Boiler water is injected into the simulated specimen through the water inlet to simulate the medium environment of the pressure vessel. A flame is injected into the heating chamber through a blowtorch to heat the boiler water and generate steam in the heating chamber. The flow rate of the steam is controlled by a flow control valve to control the temperature and pressure intensity inside the simulated specimen. By collecting the crack conditions of the simulated specimen, the influence of different temperatures and pressure intensities on the material properties is investigated. S4. Simulate the stress conditions of pressure vessels for testing: Axial pressure is applied to the simulated specimen through an axial pressure mechanism, and radial pressure is applied to the simulated specimen through a radial pressure mechanism. The influence of external pressure on the service life of the pressure vessel is tested. The external pressure environment, internal temperature environment and pressure environment of the simulated specimen can be combined to simulate the actual working conditions of the pressure vessel during service, making the test results of the material more accurate.

[0017] The beneficial effects of this invention are: 1. The specimen structure closely matches the actual working conditions, significantly improving the authenticity of the test: The simulated specimen adopts a ring structure and upper and lower mounting flange design, which completely restores the core structural characteristics of the steam boiler pressure vessel of "ring-shaped sealing + flange fixing". It accurately reproduces the ring-shaped stress characteristics and the stress concentration effect at the flange connection, and solves the problem of the stress transmission path of existing plate-shaped and round bar-shaped specimens being out of sync with reality. This makes the stress state of the material highly consistent with the actual service state of the steam boiler, providing a reliable structural basis for performance evaluation.

[0018] 2. Precise simulation of zoned operating conditions to reproduce the core workflow of a steam boiler: The simulated specimen is divided into a steam chamber and a heating chamber by a partition. With the help of a flame gun, the exclusive workflow of a steam boiler, namely "combustion heating → water-steam conversion → steam pressurization", is highly reproduced. The coupling effect of medium state transformation on material corrosion and fatigue is effectively captured, and the fit of the operating condition simulation is effectively improved, making the test accuracy more accurate.

[0019] 3. Multiple stress synergistic loading, fully covering actual stress constraints: The integrated axial pressure mechanism and radial pressure mechanism can simultaneously simulate the axial thrust of the steam boiler support, the radial extrusion stress of the water-cooled wall tube, and the erosion stress caused by the fluctuation of the medium flow rate, forming a triple coupled loading environment of "thermal stress + pressure stress + erosion stress"; accurately matching the complex stress conditions of the steam boiler.

[0020] 4. Accurately reproduces uneven heating and steam liquefaction conditions, and captures key failure mechanisms: By blocking part of the flame holes through the flame control mechanism, it can simulate uneven combustion in the furnace caused by long-term low-load operation. Combined with the linkage control of the flow control valve and pressure gauge, it can reproduce the steam liquefaction and acidic medium condensation scenarios caused by local low temperature. At the same time, it can simulate the condition of excessive heat flux density of the heating surface under long-term overload operation, effectively capturing key failure mechanisms such as accelerated corrosion and aggravated fatigue damage caused by liquefaction. It solves the defect of existing tests that ignore such core conditions, and makes the test data such as corrosion rate and crack propagation more consistent with the actual service conditions. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of a performance testing device for pressure vessels under different service temperatures according to the present invention. Figure 1 ; Figure 2 This is a schematic diagram of the structure of a performance testing device for pressure vessels under different service temperatures according to the present invention. Figure 2 ; Figure 3 This is a schematic diagram of the structure of a performance testing device for pressure vessels under different service temperatures according to the present invention. Figure 3 ; Figure 4This is a schematic diagram of the structure of a simulated specimen in a performance testing device for pressure vessels at different service temperatures according to the present invention; Figure 5 This is a bottom view of a performance testing device for a pressure vessel at different service temperatures according to the present invention. Figure 6 This is a schematic diagram of the internal structure of the radial pressure shaft in a performance testing device for a pressure vessel at different service temperatures according to the present invention. Figure 7 This is a schematic cross-sectional view of the radial pressure axis in a performance testing device for a pressure vessel at different service temperatures according to the present invention. In the diagram, 1-simulated specimen, 2-upper mounting flange, 3-lower mounting flange, 4-partition plate, 5-steam chamber, 6-heating chamber, 7-exhaust pipe, 8-flow control valve, 9-pressure gauge, 10-foundation base, 11-tension and pressure frame, 12-tension and pressure beam, 13-upper tooling flange, 14-lower tooling flange, 15-flame gun, 16-foundation column, 17-radial pressure shaft, 18-hydraulic cylinder, 19-power plate, 20-first-stage sliding shaft, 21-second-stage sliding shaft, 22-mounting hole, 23-first-stage spring, 24-spring disc, 25-second-stage spring, 26-connection groove, 27-slot, 28-connection block, 29-connection cavity, 30-C-shaped pressure block, 31-sloping surface, 3 2-Locking screw, 33-Rotating ring, 34-Flaw detector frame, 35-Axial slide block, 36-Ultrasonic phased array flaw detector, 37-Lead screw, 38-Lead screw slider, 39-First motor, 40-Large gear ring, 41-Second motor, 42-Drive gear, 43-Fixed fire plate, 44-Fan-shaped stop block, 45-Mounting shaft, 46-Circular fire chamber, 47-Flame hole, 48-Fire passage hole, 49-Avoidance notch, 50-Water inlet, 51-Switching drive shaft, 52-Circular switching groove, 53-Sliding cap, 54-Rotating limit plate, 55-Full-through positioning groove, 56-Shielding positioning groove, 57-Flame control spring, 58-Radial rotating ring, 59-Radial gear ring, 60-Radial drive gear. Detailed Implementation

[0022] Example 1 like Figures 1 to 7As shown, a performance testing device for pressure vessels under different service temperatures includes an axial pressure mechanism, a radial pressure mechanism, and a simulated specimen 1. The simulated specimen 1 is fabricated into a ring structure, with an upper mounting flange 2 and a lower mounting flange 3 fixed to its top and bottom, respectively, to simulate the actual shape of the pressure vessel. Since the load-bearing capacity of the material is affected by the actual shape, different shapes result in different force distributions and thus different effects on physical properties. Because the shape of the simulated specimen 1 is close to the actual shape of a steam boiler, compared to the traditional method of fabricating specimens into T-shapes or cylinders, the influence of the specimen's own structure on the test structure is greatly reduced. The specimen structure closely matches the actual working conditions, significantly improving the realism of the test. A partition 4 is fixed inside the simulated specimen 1, dividing it into an upper steam chamber 5 and a lower heating chamber 6 to simulate the actual working state of a pressure vessel. A flame gun 15 is installed on one side of the simulated specimen 1, and a heating opening is provided on the side wall of the simulated specimen 1 to connect to the heating chamber 6. The flame tube of the flame gun 15 extends into the heating chamber 6 through the heating opening, accurately simulating the zoned working conditions and highly replicating the specific workflow of a steam boiler: "combustion heating → water-steam conversion → steam pressurization." This effectively captures the coupled influence of medium state transformation on material corrosion and fatigue, significantly improving the fit of the working condition simulation and making the test accuracy more precise. A flow control valve 8 is connected to the upper mounting flange 2 via an exhaust pipe 7. A pressure gauge 9 is installed on the mounting flange 2. The axial pressure mechanism includes a base base 10 and a tension / pressure frame 11. A tension / pressure beam 12 is slidably mounted on the tension / pressure frame 11, and an upper tooling flange 13 is mounted on the tension / pressure beam 12. A lower tooling flange 14 is fixed on the base base 10. The radial pressure mechanism includes multiple base columns 16, which are arranged circumferentially around the lower tooling flange 14. Multiple radial pressure shafts 17 are slidably mounted on the base columns 16 along their own height direction. The radial pressure shafts 17 have the freedom to move radially along the lower tooling flange 14. The simulated specimen 1 is first tooled onto the axial pressure mechanism. Specifically, the upper mounting flange 2 and the lower mounting flange 3 of the simulated specimen 1 are respectively connected to the upper tooling flange. 13 and lower tooling flange 14 are connected, and then the flame gun 15 is installed in place. Water is injected into the simulated specimen 1, and then the performance test of the simulated specimen is carried out. The flame gun 15 is turned on to heat the simulated specimen 1, so that steam is generated in the steam chamber 5. The steam pressure in the simulated specimen 1 is measured by the pressure gauge 9. The flow control valve 8 is in the closed state, so that the steam pressure in the steam chamber 5 is continuously increased. The deformation of the material surface of the simulated specimen 1 is observed to study the effect of different steam pressures on the deformation of the material of the simulated specimen 1. When it is necessary to test under a specific steam pressure, when the pressure is too high, the flow control valve 8 is used to control the steam flow, so that the steam pressure in the steam chamber 5 is always maintained at the required value.Axial pressure is applied to the simulated specimen 1 through an axial pressure mechanism. Specifically, the tension beam 12 compresses the simulated specimen 1 downwards or stretches it upwards to apply axial pressure or tension, thus studying the effect of the combined action of axial pressure and steam pressure on the material properties of the simulated specimen 1. Radial pressure shaft 17 compresses the sidewall of the simulated specimen 1 to apply radial pressure. Applying radial loads to different positions of the simulated specimen 1 through different radial pressure shafts 17 can simulate complex radial pressure environments. In summary, by combining radial loads, steam pressure, and axial loads, complex working conditions can be simulated simultaneously. This allows for the simultaneous simulation of the axial thrust of the steam boiler support, the radial compressive stress of the water-cooled wall tubes, and the erosion stress caused by fluctuations in medium flow velocity (controlled by a flow control valve from 0.5 to 3 m / s), forming a triple-coupled loading environment of "thermal stress + pressure stress + erosion stress," accurately matching the complex stress conditions of a steam boiler.

[0023] Example 2 Based on Example 1, such as Figures 1 to 3 As shown, it also includes a flaw detection testing mechanism, which includes a rotating ring 33, a flaw detection frame 34, an axial slide 35, and an ultrasonic phased array flaw detector 36. The rotating ring 33 is rotatably mounted on the foundation base 10, the flaw detection frame 34 is fixed on the rotating ring 33, the axial slide 35 is disposed on the flaw detection frame 34, and the axial slide 35 has the freedom to move axially along the lower tooling flange 14. The ultrasonic phased array flaw detector 36 is mounted on the axial slide 35 and is located between two adjacent foundation columns 16. During the testing process, the ultrasonic phased array flaw detector 36 uses electronically controlled delay adjustment of the array element acoustic wave emission sequence to change the angle, focusing depth and coverage of the ultrasonic beam. It can perform layered focusing detection on the wall thickness, near surface, deep internal layers and flange joints of the specimen, and convert the echo signal into two-dimensional / three-dimensional imaging spectrum, defect size, crack length, defect location coordinates and other data, which correspond one by one with working condition parameters such as temperature, pressure, stress and medium flow rate, and quantitatively analyze the damage evolution law of materials under different service conditions.

[0024] Furthermore, a lead screw 37 is rotatably mounted on the flaw detection frame 34, and a lead screw slider 38 is threaded onto the lead screw 37. An axial slide block 35 is mounted on the lead screw slider 38. A first motor 39 is mounted on the flaw detection frame 34, and the output shaft of the first motor 39 is connected to the lead screw 37 via a coupling. A large gear ring 40 is mounted on the rotating ring 33. A second motor 41 is mounted on the base 10, and the output shaft of the second motor 41 is connected to a drive gear 42. The drive gear 42 meshes with the large gear ring 40, and the second motor 41 drives the large gear ring 40 to rotate via the drive gear 42. The rotating ring 33 drives the flaw detector frame 34 to rotate, causing the ultrasonic phased array flaw detector 36 to move around the circumference of the simulated specimen 1. The first motor 39 drives the lead screw 37 to rotate, causing the lead screw slider 38 to move along the axial direction of the lead screw 37, thereby driving the ultrasonic phased array flaw detector 36 to move along the axial direction of the simulated specimen 1. This allows the ultrasonic phased array flaw detector 36 to cover all positions around the circumference of the simulated specimen. By adjusting the working environment of the simulated specimen, and then using the ultrasonic phased array flaw detector 36 to detect the deformation of the simulated specimen 1, the deformation properties of the material under different working conditions can be studied.

[0025] Example 3 Based on Example 2, such as Figures 1 to 3 As shown, the radial pressure mechanism also includes a radial rotating ring 58, which is rotatably mounted on the base 10. The base column 16 is fixed on the radial rotating ring 58. A radial gear ring 59 is fitted on the radial rotating ring 58. A radial drive motor is provided on the base 10. The output shaft of the radial drive motor is connected to a radial drive gear 60. The radial drive gear 60 meshes with the radial gear ring 59. The radial drive motor drives the radial rotating ring 58 to rotate through the meshing of the radial drive gear 60 and the radial gear ring 59, so that the base column 16 can move around the circumference of the simulated specimen 1. This is used to adjust the position of the radial pressure shaft 17, which can apply radial pressure to different positions of the simulated specimen 1.

[0026] Example 4 Based on Example 3, a clearance notch 49 is provided through the upper tooling flange 13, through which the exhaust pipe 7 passes. A water inlet 50 is connected to the upper mounting flange 2. The water inlet 50 is used to inject boiler water into the simulated specimen 1 to simulate the characteristics of steam-water circulation and scaling, and to reproduce the coupled damage of erosion and wear. Specifically, scale simulation: Boiler water contains hardness ions such as calcium and magnesium, which easily precipitate scale and adhere to the inner wall of the specimen after heating. Scale will change the thermal conductivity of the metal wall and form under-deposit corrosion. At the same time, scale particles will aggravate the erosion and wear of the inner wall as they flow with steam and water. Pure water does not have scaling, thus lacking this typical failure factor. Media erosion matching: There are suspended impurities and fine scale particles in the boiler water circulation system. With the adjustable media flow rate (0.5~3m / s) of the device, the media erosion stress can be realistically reproduced, and the multi-field coupled failure of "thermal stress + pressure stress + erosion stress + corrosion" can be reproduced, making up for the deficiency of the single working condition of pure water test.

[0027] Example 5 Based on Example 4, such as Figures 1 to 4 As shown, a flame control mechanism is provided inside the heating chamber 6. The flame control mechanism includes a fixed flame plate 43 and a fan-shaped block 44. A mounting shaft 45 is fixed to the bottom of the fixed flame plate 43, and the mounting shaft 45 is fixedly connected to the simulation specimen 1. A circular flame chamber 46 is provided inside the fixed flame plate 43. Several flame holes 47 communicating with the circular flame chamber 46 are opened on the top of the fixed flame plate 43. An opening for the flame tube to pass through is opened on the side wall of the fixed flame plate 43. The fan-shaped block 44 is rotatably mounted on the top of the fixed flame plate 43. Several flame holes 48 are opened through the fan-shaped block 44. By rotating the fan-shaped block 44, the fan-shaped block 44 can block part of the flame holes 47, or the flame holes 48 of the fan-shaped block 44 can communicate with the flame holes 47. The flame emitted by the flame gun 15 enters the circular flame chamber 46 through the opening on the side wall of the fixed flame plate 43, and then is emitted through the flame holes 47 to act on the steam chamber 5. On the bottom wall, the boiler water in the steam chamber 5 is heated. By rotating the fan-shaped baffle 44, the fan-shaped baffle 44 can be deflected to different positions to block and fix the fire plate 43. When blocking, the flame holes 47 and the flame holes 48 are staggered, so that the fan-shaped baffle 44 blocks the local flame holes 47 on the fixed fire plate 43. This can simulate the uneven combustion in the furnace caused by long-term low-load operation (temperature field uniformity deviation of 5-20℃). Combined with the linkage control of the flow control valve 8 and the pressure gauge 9, it can reproduce the steam liquefaction and acid medium condensation scenario caused by local low temperature. At the same time, it can simulate the working condition of excessive heat flux density of the heating surface under long-term overload operation, effectively capturing key failure mechanisms such as accelerated corrosion and fatigue damage caused by liquefaction. This solves the defect of existing tests that ignore such core working conditions, and makes the test data such as corrosion rate and crack propagation more consistent with the actual service law.

[0028] Example 6 Based on Example 5, such as Figures 1 to 5As shown, a switching drive shaft 51 is fixed to the bottom of the fan-shaped stop 44. The switching drive shaft 51 coaxially passes through the fixed fire plate 43. A circular switching groove 52 is opened at the bottom of the simulated specimen 1. A sliding cap 53 is coaxially arranged in the circular switching groove 52. The switching drive shaft 51 is movably inserted into the circular switching groove 52. The sliding cap 53 is slidably sleeved on the switching drive shaft 51. A guide strip is fixed to the inner wall of the sliding cap 53. An axial guide groove is opened on the side wall of the switching drive shaft 51. The guide strip is slidably arranged in the axial guide groove. A rotation limiting plate 54 is fixed to the side wall of the sliding cap 53. The bottom of the simulated specimen 1 is provided with a full-through positioning groove 55 and multiple blocking positioning grooves 56 around the circular switching groove 52. Both the full-through positioning groove 55 and the blocking positioning grooves 56 are connected to the circular switching groove 52. A first step and a second step are respectively formed on the switching drive shaft 51 and the sliding cap 53. A flame-controlling spring 57 is fitted onto the sliding cap 53, with its two ends connected to the first step and the second step respectively. When the rotating limiting plate 54 is fitted into the full-through positioning groove 55, the flame-passing hole 48 connects to the flame-spraying hole 47. When the rotating limiting plate 54 is fitted into the blocking positioning groove 56... The flame holes 48 and 47 are staggered, causing the fan-shaped baffle 44 to partially block the flame holes 47 on the fixed flame plate 43. A pull ring is fixed to the bottom of the sliding cap 53. Before installing the simulation specimen 1, the position of the fan-shaped baffle 44 is adjusted according to the requirements to select whether to partially block the flame holes 47 on the fixed flame plate 43 and to select the blocking position. When it is necessary to block part of the flame holes 47, the sliding cap 53 is pulled down by the pull ring, which causes the sliding cap 53 to stretch the flame control spring 57 and move, so that the rotating limit plate 54 moves out of the full-through positioning groove 55 or the blocking positioning groove 56. Unlock the rotational freedom of the sliding cap 53 so that it can drive the switching drive shaft 51 to rotate. The switching drive shaft 51 drives the fan-shaped block 44 to rotate on the fixed fire plate 43. Adjust the blocking position of the fan-shaped block 44. After moving to the designated position, fit the rotating limit plate 54 into the blocking positioning groove 56 at the corresponding position, thereby restricting the rotation of the rotating limit plate 54 and locking the blocking position of the fan-shaped block 44. When it is not necessary to block part of the flame holes 47, simply fit the rotating limit plate 54 into the full-through positioning groove 55 to simulate the furnace combustion condition.

[0029] Example 7 Based on Example 6, such as Figures 1 to 7As shown, a power mechanism is provided at the end of the foundation column 16 away from the lower tooling flange 14. The power mechanism includes a hydraulic cylinder 18 and a power plate 19. The cylinder body of the hydraulic cylinder 18 is fixed on the foundation column 16, and the telescopic shaft of the hydraulic cylinder 18 is connected to the power plate 19. The radial pressure shaft 17 is located on the moving path of the power plate 19. The radial pressure shaft 17 includes a primary sliding shaft 20 and a secondary sliding shaft 21. A through hole is provided on the foundation column 16 for the primary sliding shaft 20 to pass through. A mounting hole 22 is provided at the end of the primary sliding shaft 20 near the power plate 19. One end of the secondary sliding shaft 21 is slidably fitted into the mounting hole 22. A primary spring 23 is provided in the mounting hole 22, and the two ends of the primary spring 23 are respectively connected to A primary sliding shaft 20 and a secondary sliding shaft 21 are connected. A spring disc 24 is fixedly sleeved on the primary sliding shaft 20, and a secondary spring 25 is sleeved on the primary sliding shaft 20. The two ends of the secondary spring 25 are respectively connected to the foundation column 16 and the spring disc 24. The elastic modulus of the secondary spring 25 is greater than that of the primary spring 23. Two symmetrical mating grooves 26 are opened on the inner wall of the primary sliding shaft 20. Slots 27 are opened on both sides of the secondary sliding shaft 21. A mating block 28 is slidably fitted in the mating groove 26. The mating block 28 can be partially inserted into the slot 27. The working state of the radial pressure shaft 17 can be adjusted by the position of the mating block 28. Specifically, when the mating block 28 is partially inserted into the slot 27, the working state of the radial pressure shaft 17 can be adjusted. The primary sliding shaft 20 and the secondary sliding shaft 21 are connected as a whole and are in working condition. When the mating block 28 is separated from the slot 27, the secondary sliding shaft 21 can slide within the primary sliding shaft 20 and is in a non-working state. Before applying radial pressure to the simulated specimen 1, the working state of the radial pressure shaft 17 is adjusted according to the pressure application position so that the radial pressure shaft 17 at the pressure application position of the simulated specimen is in working condition. Then, the radial pressure simulation is performed. The hydraulic cylinder 18 drives the power plate 19 to move closer to the radial pressure shaft 17, so that the power plate 19 squeezes the radial pressure shaft 17. The radial pressure shaft 17 in working condition squeezes the secondary spring 25 and moves closer to the simulated specimen 1, while the radial pressure shaft 21 in non-working condition... Towards the pressure shaft 17, since the elastic modulus of the secondary spring 25 is greater than that of the primary spring 23, the primary spring 23 is more easily deformed than the secondary spring 25. This causes the secondary sliding shaft 21 to compress the primary spring 23 and move it within the primary sliding shaft 20, preventing the primary sliding shaft 20 from compressing the simulated specimen 1. Thus, with a single power source, several arbitrary radial pressure shafts 17 can be driven to compress the simulated specimen as needed. This is used to simulate the radial pressure working environment of a boiler. Combined with the axial pressure mechanism, the flame control mechanism, and the steam environment simulation of the boiler water, a triple coupling of "thermal stress + pressure stress + erosion stress" is formed, accurately matching the complex stress conditions of a steam boiler, making the material performance test data more accurate.

[0030] Example 8 Based on Example 7, such as Figures 1 to 7As shown, the primary sliding shaft 20 has a mating cavity 29. The mating cavity 29 and the mating groove 26 are staggered along the height direction of the foundation column 16. The cross-sectional shape of the mating cavity 29 is C-shaped. The two ends of the mating cavity 29 are connected to the two mating grooves 26 respectively. A C-shaped pressure block 30 is provided in the mating cavity 29. The end face of the mating block 28 near the C-shaped pressure block 30 has an inclined surface 31. The two ends of the C-shaped pressure block 30 contact the inclined surfaces 31 of the two mating blocks 28 respectively. A locking screw 32 is threaded onto the primary sliding shaft 20. The tail of the locking screw 32 passes into the mating cavity 29 and contacts the C-shaped pressure block 30. The specific adjustment method of the mating block 28 is as follows: when it is necessary to connect the secondary sliding shaft 21 to the primary sliding shaft 20, tighten the locking screw 32. Tighten screw 32 to press C-shaped pressure block 30 downwards, causing C-shaped pressure block 30 to press the inclined surface 31 of mating block 28. Under the action of inclined surface 31, mating block 28 is inserted into slot 27, thereby putting radial pressure shaft 17 into working state. Conversely, loosen locking screw 32. The end of mating block 28 away from slot 27 is connected to mating return spring. After locking screw 32 is loosened, the pressing force of C-shaped pressure block 30 on mating block 28 is greatly reduced, causing mating block 28 to return to its original position under the action of mating return spring, thereby separating mating block 28 from slot 27. At this time, primary sliding shaft 20 and secondary sliding shaft 21 are in a separated state, that is, radial pressure shaft 17 is in a non-working state.

[0031] Example 9 Based on Example 8, a method for testing the performance of a pressure vessel under different service temperatures is provided, utilizing the aforementioned performance testing device for pressure vessels under different service temperatures, including the following steps: S1. Fabrication of Simulation Specimen 1: The material to be tested is scaled down proportionally to the size of the actual pressure vessel, so that a steam chamber 5 and a heating chamber 6 are formed inside the simulation specimen 1. The steam chamber 5 is used to simulate the steam environment of the pressure vessel, and the heating chamber 6 is used to simulate the temperature environment of the pressure vessel. S2, Tooling Simulation Specimen 1: The upper mounting flange 2 of simulation specimen 1 is connected to the upper tooling flange 13, and the lower mounting flange 3 of simulation specimen 1 is connected to the lower tooling flange 14. S3. Simulate the working environment of the pressure vessel for testing: Boiler water is injected into the simulated specimen 1 through the water inlet 50 to simulate the medium environment of the pressure vessel. The boiler water is heated by spraying flame into the heating chamber 6 through the flame gun 15, so that steam is generated in the heating chamber 6. The flow rate of the steam is controlled by the flow control valve 8 to control the temperature and pressure intensity inside the simulated specimen 1. By collecting the crack condition of the simulated specimen 1, the influence of different temperatures and pressure intensities on the material properties is investigated. S4. Simulate the stress conditions of the pressure vessel for testing: Axial pressure is applied to the simulated specimen 1 through the axial pressure mechanism, and radial pressure is applied to the simulated specimen 1 through the radial pressure mechanism. The influence of external pressure on the service life of the pressure vessel is tested. The external pressure environment, internal temperature environment and pressure environment of the simulated specimen 1 can be combined to simulate the actual working conditions of the pressure vessel during service, making the test results of the material more accurate.

Claims

1. A performance testing device for pressure vessels at different service temperatures, characterized in that, The device includes an axial pressure mechanism, a radial pressure mechanism, and a simulated test specimen. The simulated test specimen is manufactured in a ring shape, with an upper mounting flange and a lower mounting flange fixed to its top and bottom, respectively, to simulate the actual shape of a pressure vessel. A partition is fixed inside the simulated test specimen, dividing it into an upper steam chamber and a lower heating chamber to simulate the actual working state of a pressure vessel. A flame gun is installed on one side of the simulated test specimen, and a heating opening communicating with the heating chamber is opened on the side wall of the simulated test specimen. The flame nozzle of the flame gun extends into the heating chamber through the heating opening. Inside, the upper mounting flange is connected to a flow control valve via an exhaust pipe. A pressure gauge is installed on the upper mounting flange. The axial pressure mechanism includes a base and a tension / pressure frame. A tension / pressure beam is slidably mounted on the tension / pressure frame. An upper tooling flange is mounted on the tension / pressure beam. A lower tooling flange is fixed on the base. The radial pressure mechanism includes multiple base columns arranged around the circumference of the lower tooling flange. Multiple radial pressure shafts are slidably mounted on the base columns along their height direction. The radial pressure shafts have the freedom to move radially along the lower tooling flange.

2. The performance testing device for a pressure vessel under different service temperatures according to claim 1, characterized in that, A power mechanism is provided at the end of the foundation column away from the lower tooling flange. The power mechanism includes a hydraulic cylinder and a power plate. The cylinder body of the hydraulic cylinder is fixed on the foundation column, the telescopic shaft of the hydraulic cylinder is connected to the power plate, and the radial pressure shaft is located on the moving path of the power plate.

3. The performance testing device for a pressure vessel under different service temperatures according to claim 2, characterized in that, The radial pressure shaft includes a primary sliding shaft and a secondary sliding shaft. The foundation column has a through hole for the primary sliding shaft to pass through. The end of the primary sliding shaft near the power plate has a mounting hole. One end of the secondary sliding shaft is slidably fitted into the mounting hole. A primary spring is installed in the mounting hole. The two ends of the primary spring are respectively connected to the primary sliding shaft and the secondary sliding shaft. A spring disc is fixedly sleeved on the primary sliding shaft. A secondary spring is sleeved on the primary sliding shaft. The two ends of the secondary spring are respectively connected to the foundation column and the spring disc. The elastic modulus of the secondary spring is greater than that of the primary spring.

4. The performance testing device for a pressure vessel under different service temperatures according to claim 3, characterized in that, The inner wall of the primary sliding shaft has two symmetrically formed mating grooves, and slots are formed on both sides of the secondary sliding shaft. A mating block is slidably fitted in the mating groove, and the mating block can be partially inserted into the slot.

5. The performance testing device for a pressure vessel under different service temperatures according to claim 4, characterized in that, The primary sliding shaft is provided with a docking cavity. The docking cavity and the docking groove are staggered along the height direction of the foundation column. The cross-sectional shape of the docking cavity is C-shaped. The two ends of the docking cavity are respectively connected to the two docking grooves. A C-shaped pressure block is provided in the docking cavity. The end face of the docking block near the C-shaped pressure block is provided with an inclined surface. The two ends of the C-shaped pressure block respectively contact the inclined surfaces of the two docking blocks. A locking screw is threaded on the primary sliding shaft. The tail of the locking screw passes into the docking cavity and contacts the C-shaped pressure block.

6. The performance testing device for a pressure vessel under different service temperatures according to claim 1, characterized in that, It also includes a flaw detection and testing mechanism, which includes a rotating ring, a flaw detection frame, an axial slide, and an ultrasonic phased array flaw detector. The rotating ring is rotatably mounted on the foundation base, the flaw detection frame is fixed on the rotating ring, the axial slide is disposed on the flaw detection frame, the axial slide has the degree of freedom to move axially along the lower tooling flange, and the ultrasonic phased array flaw detector is mounted on the axial slide and is located between two adjacent foundation columns.

7. The performance testing device for a pressure vessel under different service temperatures according to claim 6, characterized in that, A lead screw is rotatably mounted on the flaw detection frame, and a lead screw slider is threaded onto the lead screw. An axial slide block is mounted on the lead screw slider. A first motor is mounted on the flaw detection frame, and the output shaft of the first motor is connected to the lead screw via a coupling. A large gear ring is mounted on the rotating ring. A second motor is mounted on the base, and the output shaft of the second motor is connected to a drive gear, which meshes with the large gear ring.

8. The performance testing device for a pressure vessel under different service temperatures according to claim 1, characterized in that, The heating chamber is equipped with a flame control mechanism, which includes a fixed flame plate and a fan-shaped baffle. The bottom of the fixed flame plate is fixed with an installation shaft, which is fixedly connected to the simulated test specimen. The fixed flame plate has a circular flame chamber inside, and the top of the fixed flame plate has several flame holes that communicate with the circular flame chamber. The side wall of the fixed flame plate has an opening for the flame tube to pass through. The fan-shaped baffle is rotatably installed on the top of the fixed flame plate, and several flame holes are opened through the fan-shaped baffle. By rotating the fan-shaped baffle, the fan-shaped baffle can block part of the flame holes, or the flame holes of the fan-shaped baffle can be connected to the flame holes.

9. The performance testing device for a pressure vessel under different service temperatures according to claim 1, characterized in that, An clearance notch is provided through the upper tooling flange, through which the exhaust pipe passes. A water inlet is connected to the upper mounting flange, which is used to inject boiler water into the simulated specimen.

10. A method for testing the performance of a pressure vessel under different service temperatures, comprising testing using the performance testing apparatus for a pressure vessel under different service temperatures as described in claim 9, characterized in that... Includes the following steps: S1. Fabrication of a simulated test specimen: The material to be tested is scaled down proportionally to the size of the actual pressure vessel, so that a steam chamber and a heating chamber are formed inside the simulated test specimen. The steam chamber is used to simulate the steam environment of the pressure vessel, and the heating chamber is used to simulate the temperature environment of the pressure vessel. S2, Tooling Simulation Specimen: The upper mounting flange of the simulation specimen is connected to the upper tooling flange, and the lower mounting flange of the simulation specimen is connected to the lower tooling flange. S3. Simulate the working environment of a pressure vessel for testing: Boiler water is injected into the simulated specimen through the water inlet to simulate the medium environment of the pressure vessel. A flame is injected into the heating chamber through a blowtorch to heat the boiler water and generate steam in the heating chamber. The flow rate of the steam is controlled by a flow control valve to control the temperature and pressure intensity inside the simulated specimen. By collecting the crack conditions of the simulated specimen, the influence of different temperatures and pressure intensities on the material properties is investigated. S4. Simulate the stress conditions of pressure vessels for testing: Axial pressure is applied to the simulated specimen through an axial pressure mechanism, and radial pressure is applied to the simulated specimen through a radial pressure mechanism. The influence of external pressure on the service life of the pressure vessel is tested. The external pressure environment, internal temperature environment and pressure environment of the simulated specimen can be combined to simulate the actual working conditions of the pressure vessel during service, making the test results of the material more accurate.

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