Multi-point pipeline radial stress measuring device and measuring method
Through the multi-point pipeline radial stress measurement device, the pressure sensor unit and reverse support force are used to solve the problem of difficult to measure residual stress and errors in the prior art, real-time monitoring and control of pipeline stress changes is achieved, and the cutting process is ensured to be safe and efficient.
Patent Information
- Application Number
- CN202311721231.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-14
- Publication Date
- 2025-06-17
AI Technical Summary
It is difficult for the prior art to measure the residual stress of the pipeline in advance without destroying the pipeline, and the existing measurement methods have a large error for cold-coiled steel pipes with large processing residual stresses, and it is impossible to measure the accurate overall stress distribution of the pipeline.
A multi-point pipe radial stress measurement device is adopted, which includes multiple pressure sensor units. The piezoelectric sensor probe is pressed against the pipe surface by adjusting the lead screw and buffering spring, monitoring the pressure changes of the pipe in real time, and offsetting the stress deformation of the pipe through reverse support.
It realizes the measurement of stress before cutting of the pipeline, and monitors stress changes in real time and accurately during the cutting process to avoid equipment damage and safety accidents caused by pipeline rebound, while ensuring the centering of pipelines before and after cutting, ensuring efficient and safe pipe repair or equipment replacement.
Smart Images
Figure CN120160729A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of pipeline stress monitoring, and particularly relates to a multi-point pipeline radial stress measuring device, and also relates to a multi-point pipeline radial stress measuring method. Background Art
[0002] When pipelines and station equipment are found to have irreparable defects and need to be replaced, the pipelines need to be cut. Since the pipelines in actual operation often bear large internal forces (bending moment, torque and axial force), the pipelines have high stress, and the pipeline springback during cutting will cause damage to the cutting equipment or safety accidents. At present, mechanical equipment is mostly used to support around the pipeline to prevent springback after pipeline cutting, and the commonly used pipeline residual stress testing methods mainly include the strain gauge method and the ray method.
[0003] The principle of measuring pipeline stress by strain gauges is: calculating the participation stress before pipeline cutting by measuring the stress value difference before and after pipeline cutting by strain gauges. This method requires cutting the pipeline or making reference holes, so it is impossible to pre-measure the pipeline residual stress and specify the support reinforcement plan in advance without damaging the pipeline; the ray method measures the participation stress by measuring the lattice parameters of the in-service pipeline and comparing them with zero-stress metal powder, and calculating the participation stress of the pipeline. This method can pre-measure the pipeline residual stress, but according to the actual test results, this method has large errors for cold-rolled steel pipes with large processing residual stress and cannot measure the accurate overall stress distribution of the pipeline. At the same time, the stress measured in this way is not the real stress that causes the large springback of the pipeline. Summary of the Invention
[0004] The object of the present invention is to provide a multi-point pipeline radial stress measuring device, which can measure the stress before pipeline cutting and accurately measure the change of pipeline stress during the cutting process in real time.
[0005] Another object of the present invention is to provide a multi-point pipeline radial stress measuring method.
[0006] The technical solution adopted by the present invention is that the multi-point pipeline radial stress measuring device includes a base, an outer sensor fixing frame and an inner pressure sensor fixing ring are arranged on the base, the inner pressure sensor fixing ring is fixed on the inner wall of the outer sensor fixing frame, and further includes a plurality of pressure sensor units, and the plurality of pressure sensor units pass through the outer sensor fixing frame and the inner pressure sensor fixing ring and are connected to the outer wall of the pipeline; the plurality of pressure sensor units are used to monitor the pressure change of the pipeline.
[0007] The characteristics of the present invention also lie in that
[0008] The pressure sensor unit includes an adjusting lead screw. One end of the adjusting lead screw is provided with a lead screw adjusting knob, and the other end of the adjusting lead screw is connected to a bearing. The bearing is connected to a buffer spring, and the buffer spring is connected to a piezoelectric sensor probe. The piezoelectric sensor probe is connected to the outer wall of the pipeline. The piezoelectric sensor probe is electrically connected to a pressure display.
[0009] The buffer spring is connected to the piezoelectric sensor probe by means of threading or welding.
[0010] There are 8 pressure sensor units, and they are evenly distributed on the outer wall of the pipeline.
[0011] The pipeline is located at the center of the base.
[0012] Another technical solution adopted by the present invention is a multi-point pipeline radial stress measurement method, which is specifically implemented according to the following steps:
[0013] Step 1: Through the adjusting lead screw of the pressure sensor unit, the piezoelectric sensor probe is pressed tightly on the surface of the pipeline. The pressure display shows the pressure value of each piezoelectric sensor probe. By turning the lead screw adjusting knob, the movement of the adjusting lead screw is controlled to control the piezoelectric sensor probe, so that the pressure value of each piezoelectric sensor probe is the same, which is recorded as the initial pressure value P0.
[0014] Step 2: Start the pipeline cutting equipment for operation. During the cutting process, the pipelines on both sides of the cutting line generate relative offsets under the action of internal forces. The offset pipelines exert extrusion on any one or more pressure sensor units. The pressure display monitors the change in the pressure value. At this time, a reverse supporting force needs to be applied to ensure that the pressure value of the pressure display is always close to or equal to the initial pressure value P0. At this time, the deformation stress of the pipeline is offset.
[0015] The beneficial effects of the present invention are as follows: The measurement device of the present invention can monitor the deformation stress generated during the cutting process of the pipeline in real time and display the specific stress value. The on-site construction personnel can apply a reverse force to offset the stress deformation generated by the pipeline, avoid damage to the cutting equipment caused by the pipeline rebounding during cutting, prevent the occurrence of safety accidents, and at the same time, provide guarantee for the centering of the pipeline before and after cutting, ensure the high efficiency of pipeline repair or equipment replacement and pipeline safety. Description of the Drawings
[0016] Figure 1 is a schematic structural diagram of the multi-point pipeline radial stress measurement device of the present invention;
[0017] Figure 2 is a schematic structural diagram of the multi-point pipeline radial stress measurement device of the present invention;
[0018] In the figure, 1. Pressure sensor unit, 2. Pressure display, 3. Piezoelectric sensor probe, 4. Buffer spring, 5. Adjusting lead screw, 6. Lead screw adjusting knob, 7. Inner pressure sensor fixing ring, 8. Outer sensor fixing frame, 9. Base, 10. Pipeline. Detailed implementation mode
[0019] The present invention will be described in detail below in conjunction with the accompanying drawings and specific implementation modes.
[0020] Embodiment 1
[0021] The multi-point pipeline radial stress measurement device of the present invention, as Figure 1 shown, includes a base 9. An outer sensor fixing frame 8 and an inner pressure sensor fixing ring 7 are arranged on the base 9. The inner pressure sensor fixing ring 7 is fixed on the inner wall of the outer sensor fixing frame 8. It also includes a plurality of pressure sensor units 1. The plurality of pressure sensor units 1 pass through the outer sensor fixing frame 8 and the inner pressure sensor fixing ring 7 and are connected to the outer wall of the pipeline 10; the pipeline 10 is located at the center of the base 9; the plurality of pressure sensor units 1 are evenly distributed on the outer wall of the pipeline 10;
[0022] There are 8 pressure sensor units 1; and they are evenly distributed on the outer wall of the pipeline 10;
[0023] The pressure sensor unit 1 is as Figure 2 shown, includes an adjusting lead screw 5. One end of the adjusting lead screw 5 is provided with a lead screw adjusting knob 6. The other end of the adjusting lead screw 5 is connected to a bearing. The bearing is connected to a buffer spring 4. The buffer spring 4 is connected to the piezoelectric sensor probe 3 by threading or welding. The piezoelectric sensor probe 3 is electrically connected to the pressure display 2; the piezoelectric sensor probe 3 is connected to the outer wall of the pipeline 10; the adjusting lead screw 5 realizes the advance and retreat of the lead screw by manually screwing the lead screw adjusting knob 6, so as to adjust the pressure value of the piezoelectric sensor probe.
[0024] The stress measurement device of the present invention can be applied to the radial stress determination of steel pipelines and pipeline accessories with a nominal outer diameter D of 114.3 - 1422 mm, a wall thickness of 1 - 70 mm, and a material yield strength of 245 - 1000 MPa.
[0025] The stress measurement device of the present invention can measure the stress caused by internal forces (bending moment, torque and axial force) of the pipeline before pipeline cutting and monitor the real-time change of pipeline stress during the cutting process. According to the measured pipeline stress, determine the accurate support position and the value of the support force; during the cutting process, according to the measured change of pipeline stress, put forward adjustment suggestions for the value of the support force. It can avoid damage to the cutting equipment caused by pipeline springback during cutting, prevent the occurrence of safety accidents, and at the same time, provide guarantee for the alignment of the pipeline before and after cutting, ensure the high efficiency of pipeline repair or equipment replacement and pipeline safety.
[0026] Example 2
[0027] The multi-point pipeline radial stress measurement method of the present invention is specifically implemented according to the following steps:
[0028] Step 1: Through the adjusting screw 5 of the pressure sensor unit 1, press the piezoelectric sensor probe 3 tightly against the surface of the pipeline 10; the pressure value of each piezoelectric sensor probe 3 will be displayed on the pressure display 2. By turning the adjusting screw adjusting handle 6, control the movement of the adjusting screw 5 to control the piezoelectric sensor probe 3, so that the pressure values of each piezoelectric sensor probe 3 are the same, denoted as the initial pressure value P0, ensuring that each piezoelectric sensor probe 3 is subjected to the same force in the initial state. In this way, during the measurement process, monitor the pipeline stress through the pressure changes of different piezoelectric sensor probes 3;
[0029] Step 2: Start the pipeline cutting equipment for operation. When the cutting amount reaches a certain depth, the pipeline 10 on both sides of the cutting line generates relative displacement under the action of internal forces (bending moment, torque and axial force). The displaced pipeline 10 squeezes any one or more pressure sensor units 1, and the pressure display 2 monitors the change of the pressure value. At this time, a reverse supporting force needs to be applied to ensure that the pressure value of the pressure display 2 is always close to P0, ensuring that the difference in its pressure value is within 0.2 MPa. At this time, the pipeline deformation stress is offset, preventing the pipeline deformation from further expanding and causing damage to the cutting equipment and safety accidents.
[0030] Example 3
[0031] The multi-point pipeline radial stress measurement method of the present invention is specifically implemented according to the following steps:
[0032] Step 1: Through the adjusting screw 5 of the pressure sensor unit 1, press the piezoelectric sensor probe 3 tightly against the surface of the pipeline 10; the pressure value of each piezoelectric sensor probe 3 will be displayed on the pressure display 2. By turning the adjusting screw adjusting handle 6, control the movement of the adjusting screw 15 to control the piezoelectric sensor probe 3, so that the pressure values of each piezoelectric sensor probe 3 are the same, denoted as the initial pressure value P0, P0 = 25 MPa;
[0033] Step 2: Start the pipeline cutting equipment for operation; when the cutting amount reaches a certain depth, the pipeline on both sides of the cutting line generates relative displacement under the action of internal forces (bending moment, torque and axial force). The displaced pipeline squeezes one of the piezoelectric sensor probes 3, and the pressure display 3 monitors the pressure value P7s = 300 MPa, reminding the construction personnel to pay attention to applying a reverse supporting force to prevent the pipeline from bursting open after it is completely disconnected.
[0034] At this time, it indicates that stress is generated in the pipeline along the direction of the piezoelectric sensor probe 3. The real-time stress P7S in the pipeline along the direction of the piezoelectric sensor probe 3 is the stress value P7s monitored at this time minus the initial stress P0, and P7S = P7s - P0 = 275 MPa.
[0035] As the cutting amount increases, the stress in the pipeline is gradually released, and the pressure applied to the piezoelectric sensor probe 3 gradually increases. After the pipeline is completely disconnected, the final pressure value P7z of the piezoelectric sensor probe 3 is 390 MPa, and the values of other pressure sensors remain unchanged. The final stress Pz in the pipeline along the direction of the piezoelectric sensor probe 3 is the stress value P7z monitored at this time minus the initial stress P0, and Pz = P7z - P0 = 365 MPa.
[0036] If the residual stress of the pipeline is large, when the pipeline is completely disconnected, the relative offset of the pipe orifice is too large, which may cause equipment damage and safety accidents.
[0037] Therefore, when the cutting amount reaches 2 / 3 of the actual wall thickness of the pipeline, a reverse supporting force should be applied according to the real-time stress P7s monitored at that time. The reverse force can be applied using large mechanical equipment, jacks or other heavy objects according to the on-site construction conditions until the pressure value P7s displayed by the pressure sensor is close to the initial stress P0; as the cutting amount of the pipeline increases, the reverse supporting force can be continuously applied according to the real-time value of the sensor to ensure that the pressure value displayed by the pressure sensor is always close to P0. At this time, even if the pipeline is completely disconnected, the reverse supporting force of the same magnitude applied according to the measured stress value in the early stage can ensure that the pipe orifice will not produce too large an offset, thus ensuring the safety of the cutting equipment and the operating personnel.
Claims
1. Multi-point pipeline radial stress measurement device, characterized in that, It includes a base (9), on which an outer sensor fixing frame (8) and an inner pressure sensor fixing ring (7) are provided. The inner pressure sensor fixing ring (7) is fixed on the inner wall of the outer sensor fixing frame (8). It also includes a plurality of pressure sensor units (1), and the plurality of pressure sensor units (1) pass through the outer sensor fixing frame (8) and the inner pressure sensor fixing ring (7) and are in contact with the outer wall of the pipeline (10); the plurality of pressure sensor units (1) are used to monitor the pressure change of the pipeline (10).
2. The multi-point pipeline radial stress measurement device according to claim 1, characterized in that, The pressure sensor unit (1) includes an adjusting lead screw (5), one end of the adjusting lead screw (5) is provided with a lead screw adjusting knob (6), the other end of the adjusting lead screw (5) is connected to a bearing, the bearing is connected to a buffer spring (4), and the buffer spring (4) is connected to a piezoelectric sensor probe (3); the piezoelectric sensor probe (3) is connected to the outer wall of the pipeline (10); the piezoelectric sensor probe (3) is electrically connected to a pressure display (2).
3. The multi-point pipeline radial stress measurement device according to claim 2, characterized in that, The buffer spring (4) and the piezoelectric sensor probe (3) are connected by threading or welding.
4. The multi-point pipeline radial stress measurement device according to claim 2, characterized in that, Eight pressure sensor units (1) are provided; and they are evenly distributed on the outer wall of the pipeline (10).
5. The multi-point pipeline radial stress measurement device according to claim 1, characterized in that, The pipeline (10) is located at the center of the base (9).
6. Multi-point pipeline radial stress measurement method, using the multi-point pipeline radial stress measurement device according to any one of claims 2-4, characterized in that, Specifically, it is implemented according to the following steps: Step 1, through the adjusting lead screw (5) of the pressure sensor unit (1), the piezoelectric sensor probe (3) is pressed against the surface of the pipeline (10); the pressure display (2) displays the pressure value of each piezoelectric sensor probe (3). By turning the lead screw adjusting knob (6), the movement of the adjusting lead screw (5) is controlled to control the piezoelectric sensor probe (3) so that the pressure value of each piezoelectric sensor probe (3) is the same, denoted as the initial pressure value P0; Step 2, start the pipeline cutting equipment for operation. During the cutting process, the pipelines (10) on both sides of the cutting line generate relative offsets under the internal force, and the offset pipelines (10) exert extrusion on any one or more pressure sensor units (1). The pressure display (2) monitors the change of the pressure value. At this time, a reverse supporting force needs to be applied to ensure that the pressure value of the pressure display (2) is always close to or equal to the initial pressure value P0. At this time, the pipeline deformation stress is offset.