Device and method for detecting out-of-roundness of inner cross section of elbow for power plant

Abstract

The invention belongs to the technical field of special equipment detection equipment, and provides a device for detecting the out-of-roundness of the inner section of an elbow for a power plant, and the device comprises a detection unit which comprises an annular detection unit housing, the detection unit housing is provided with holes which are uniformly distributed, and the center of the detection unit housing is provided with a displacement sensor array. The displacement sensor array is connected with the controller through a connecting line and comprises an illuminating lamp arranged in the center, a circle of sensor telescopic probes are arranged on the periphery of the illuminating lamp, and the sensor telescopic probes are controlled by the controller and stretch out and draw back in holes in a shell of the detection unit. The position and the posture of the shell of the detection unit are adjusted; and diameter data are measured. The invention further provides a method for measuring the out-of-roundness of the inner section of the elbow of the elbow for the power plant, and the out-of-roundness detection device and method solve the problems that no special detection equipment exists in the prior art, and the out-of-roundness of the interior of the elbow is difficult to measure.

Description

Technical Field

[0001] The invention belongs to the technical field of special equipment detection equipment, and specifically relates to a device for detecting the non-circularity of the inner section of a curved pipe elbow used in a power plant. The invention also relates to a method for measuring the non-circularity of the inner section of a curved pipe elbow used in a power plant. Background Art

[0002] Out-of-roundness is a quantity that describes the degree of elliptical shape of an object, and is usually used to describe the degree of out-of-roundness of an object on two axes. Out-of-roundness can be calculated by comparing the ratio of the difference between the longest diameter and the shortest diameter of an object to the average value of the diameter of the object. The closer this ratio is to 1, the smaller the ellipticity of the object, and vice versa. The out-of-roundness in "Power Station Bends" (DL / T515-2018) is defined as: the ratio of twice the difference between the maximum outer diameter and the minimum outer diameter on the same section of the bend to the sum of the maximum outer diameter plus the minimum outer diameter, expressed as a percentage. The "Technical Supervision Regulations for Metals in Thermal Power Plants" (DL / T438-2023) stipulates that the internal geometry of the elbow should be inspected for appearance quality before factory piping. If obvious flatness is found, the out-of-roundness should be measured from the inside.

[0003] At present, the installed capacity of thermal power plants in my country tends to be stable. The units built before 2010 have been running for more than 100,000 hours, which has exceeded half of the design life. With the continuous increase in current electricity consumption, the proportion of new energy installed capacity has increased year by year, and the deep peak regulation of traditional energy has become more frequent. The four pipes have poor operating conditions, and the materials used are mostly low-alloy steel. The microstructure of low-alloy steel changes after long-term operation at high temperature, which leads to cumulative changes in geometric dimensions. Bends and elbows are the most important components of steam and water pipelines and are widely used in the above-mentioned pipe systems. During the manufacturing process, elbows or bends are mostly cold-bent and hot-calibrated. According to the requirements of "Power Station Bends" (DL / T515-2018), the out-of-roundness of hot-bent bends should not be greater than 7%, and the out-of-roundness of cold-bent bends should not be greater than 8%; for pipelines with a design pressure greater than 8MPa, the out-of-roundness should not be greater than 5%. Therefore, the manufactured bends themselves have the problem of out-of-roundness, but in actual operation, as time goes by, the ellipticity of the bends will tend to "re-round". Creep deformation occurs during this process. When the deformation reaches a certain value, the elbow structure is prone to instability and equipment damage. Therefore, the "Technical Supervision Regulations for Metals in Thermal Power Plants" (DL / T438-2023) and the "Technical Inspection Regulations for Boiler Safety" (TSG 11-2020) both have requirements for the out-of-roundness of elbows.

[0004] The existing technology mainly uses the outer wall detection method to measure the out-of-roundness of the elbow of the pipe. A vernier caliper is used to measure back and forth on the elbow of the pipe. After the inspection personnel feel the maximum value, they read the data. However, there is no better method to measure the out-of-roundness from the inside as described in the standard. Either the pipe is cut and damaged, or it is extrapolated from the outer wall. The measurement results are inaccurate and not intuitive.

[0005] In view of the above shortcomings, it is urgent to develop a new measurement method that can measure the out-of-roundness of the pipe elbow from the inside to avoid position errors. Summary of the invention

[0006] The first object of the present invention is to provide a device for detecting the non-circularity of the inner section of a curved pipe elbow for a power plant, which solves the problem that the prior art has no dedicated detection equipment and is difficult to measure the non-circularity of the inner section of the curved pipe.

[0007] The second purpose of the present invention is to provide a method for measuring the non-circularity of the inner section of a curved pipe elbow used in a power plant, which solves the problem of manual measurement of the non-circularity of the inner wall curved pipe elbow in the prior art, which has large human operation factors, large measurement errors, and non-intuitive data.

[0008] The first technical solution adopted by the present invention is: a device for detecting the non-roundness of the inner section of a curved pipe elbow for a power plant, comprising a detection unit, the detection unit comprising an annular detection unit shell, the detection unit shell being provided with evenly distributed holes, a displacement sensor array being arranged at the center of the detection unit shell, the displacement sensor array being connected to a controller via a connecting line, the displacement sensor array comprising a lighting lamp arranged at the center, a circle of retractable sensor probes being arranged around the lighting lamp, the retractable sensor probes being controlled by the controller to retract in the holes on the detection unit shell to adjust the position and posture of the detection unit shell and measure diameter data.

[0009] The technical solution adopted by the present invention is also characterized in that:

[0010] Furthermore, the entire array of displacement sensors is fixed by hexagonal bolts.

[0011] Furthermore, the connecting line is composed of a connecting cable, an optical fiber and a carbon fiber thread. The connecting cable is used for power supply. A camera is provided at the end of the optical fiber for photographing the internal environment. The carbon fiber thread provides tension.

[0012] Furthermore, the controller is preset with an out-of-roundness calculation program, and the controller is provided with direction control keys and multi-function buttons for controlling and adjusting the position and posture of the entire array of displacement sensors;

[0013] The controller is equipped with a touch screen display with the following functions:

[0014] 1) The touch screen is provided with an on / off button for the displacement sensor array and a window for displaying the displacement sensor measurement data. Clicking the window data saves the data.

[0015] 2) The power of the controller is supplied by a rechargeable battery;

[0016] 3) The touch screen is also provided with a button for starting calculation and a page for displaying the final result, which displays the final out-of-roundness value obtained through the calculation program.

[0017] The second technical solution adopted by the present invention is: a method for measuring the non-circularity of the inner section of a curved pipe elbow for a power plant, and the above-mentioned non-circularity detection device is implemented according to the following steps:

[0018] Step 1: Place the detection unit into the elbow to be tested, turn on the controller, and the light will automatically light up. The controller adjusts the position of the detection unit, and observes whether the detection unit reaches the predetermined position through the touch screen;

[0019] Step 2. When the detection unit reaches the predetermined position, adjust the probe posture through the direction control key to keep it parallel to the elbow section to be detected, then click the multi-function button to call out the start detection unit, and calibrate the data center, that is, the center of the data section, that is, the actual measured center of the section. The controller controls the sensor's retractable probe to retract in sequence to read the diameter data of the entire section;

[0020] Step 3. Click the multi-function button to call up the analysis unit, and draw a cross-sectional diagram of the displacement sensor data with the calibration data center as the center. In the diagram, select the maximum value of the inner and outer arc data, which is D1, and select the maximum value of the neutral surface data, which is D2.

[0021] Step 4, the controller uses a pre-stored calculation program to calculate the final value a of the out-of-roundness of the elbow to be tested according to the nominal outer diameter Di of the elbow to be tested and the two radial diameter values ​​D1 and D2 obtained by detection;

[0022] Step 5: After obtaining the calculation result, the controller displays the value of the out-of-roundness a on the touch screen.

[0023] The second technical solution adopted by the present invention is also characterized in that:

[0024] Furthermore, in step 1, the multi-function button is used to control the sensor's retractable probes to extend two probes symmetrically 180° to clamp the detection unit, and then the other direction is adjusted until it is parallel to the cross section, and the detection unit reaches a predetermined position.

[0025] Furthermore, in step 2, two symmetrical 180° probes perpendicular to the first probe are excited in sequence, and then other probes are excited in sequence to read the diameter data of the entire cross section.

[0026] Furthermore, the out-of-roundness numerical detection of the elbow to be tested in step 4 is specifically as follows: Assuming that the nominal inner diameter of the elbow to be tested is Di, input Di, then the calculation formula of the out-of-roundness a is: a=(D2-D1)×100% / Di.

[0027] The beneficial effects of the present invention are:

[0028] The detection device of the present invention can directly read the diameter data of the entire cross-section by setting up a whole array of displacement sensors and a retractable probe of the sensor, and then calculate the out-of-roundness of the elbow to be tested based on the measured data. Compared with manual measurement of the out-of-roundness of the inner wall bend elbow, the measurement error is small, the data is intuitive, and it is more accurate and reliable.

[0029] The detection device of the present invention is provided with an illumination lamp and a camera, which can assist an operator to obtain the out-of-roundness data of the elbow to be detected more accurately, intuitively and quickly. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 The structure of the device for detecting the non-roundness of the inner section of the elbow of the power plant of the present invention is schematically shown. Figure 1 ;

[0031] Figure 2 The structure of the device for detecting the non-roundness of the inner section of the elbow of the power plant of the present invention is schematically shown. Figure 2 ;

[0032] Figure 3 This is a front view of the installation position when the method of the present invention detects the elbow to be inspected;

[0033] Figure 4 It is a cross-sectional diagram of data after detection by the method of the present invention.

[0034] In the figure: 1. Detection unit housing, 2. Displacement sensor array, 3. Illumination lamp, 4. Sensor retractable probe, 5. Connecting wire, 6. Direction control key, 7. Multi-function button, 8. Controller, 9. Elbow to be tested. DETAILED DESCRIPTION

[0035] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] The present invention provides a device for detecting the non-circularity of the inner section of a pipe elbow for use in a power plant, such as Figure 1 , Figure 2 As shown, the structure of the internal non-roundness detection device of the present invention is: the detection unit shell 1 is an annular shell with evenly distributed holes on it, which is convenient for the extension and retraction of the sensor retractable probe 4, the displacement sensor array 2 controls the displacement of the sensor retractable probe 4 and records it, the lighting lamp 3 ensures reliable lighting, so that the inspector can see the inner wall morphology of the elbow from the display screen of the controller 8, the controller and the display screen are connected by a connecting line 5, the brightness is controlled by optical fiber, the sensor control array is powered by a cable, the direction control key 6 is used to control the carbon fiber wire to adjust the probe angle, and the multi-function button 7 is used to set parameters, take pictures, record, etc.

[0037] The controller 8 is preset with an out-of-roundness calculation program and is equipped with a touch screen (display screen), and its functions are as follows:

[0038] 1) The touch screen is provided with an on / off button for the entire displacement sensor array 2, and a window for displaying the measurement data of the entire displacement sensor array 2. Clicking the data in the window saves the data;

[0039] 2) The power consumption of the controller 8 is mainly supplied by rechargeable batteries. It mainly provides the internal probe light source, provides the pulling force for the movement of the carbon fiber wire, controls the operation of the program, and calculates the out-of-roundness.

[0040] 3) The touch screen is also provided with a button for starting calculation and a page for displaying the final result, which displays the final out-of-roundness value obtained by the calculation program. Assuming that the nominal inner diameter of the elbow 9 to be measured is Di, Di is input, and the calculation formula of the out-of-roundness a is: a=(D2-D1)×100% / Di, and the value a is displayed on the touch screen in the controller 8.

[0041] The present invention also provides a method for measuring the out-of-roundness of the inner section of a pipe elbow for a power plant, referring to Figure 1 , Figure 2 , Figure 3 The internal non-circularity measuring method of the present invention is implemented by using the aforementioned internal non-circularity detection device according to the following steps:

[0042] Step 1: Place the detection probe into the elbow 9 to be tested.

[0043] Turn on the controller 8, turn on the power, the lighting lamp 3 automatically lights up, and observe from the screen whether the probe reaches the predetermined position;

[0044] Step 2. After reaching the predetermined position, adjust the probe posture through the direction control key 6, try to keep it parallel to the cross section, then click the multi-function button 7 to call out the start detection unit, and calibrate the data center (the center of the data section circle) at the same time. The displacement sensor array 2 controls the sensor retractable probe 4 to move in sequence to read the diameter data of the entire cross section.

[0045] Click the multi-function button 7 to call up the analysis unit, and draw a cross-sectional diagram of the displacement sensor data with the calibration data center as the center. In the diagram, select the maximum value of the inner and outer arc data, which is D1, and select the maximum value of the neutral surface data, which is D2.

[0046] The controller 8 uses a pre-stored calculation program to calculate the final value a of the out-of-roundness of the elbow 9 to be tested according to the nominal outer diameter Di of the elbow 9 to be tested and the two radial diameter values ​​D1 and D2 obtained by detection. The calculation formula is: a = (D2-D1) × 100% / Di;

[0047] After obtaining the calculation result, the controller 8 displays the value of the out-of-roundness a on the touch screen.

[0048] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0049] Example 1

[0050] According to the above steps of the method of the present invention, a 90° elbow of a main steam pipe is tested. The material is T91 and the inner diameter Di is 347 mm. Macroscopic inspection shows that the elbow is relatively flat. According to the specification, the out-of-roundness needs to be measured from the inside. The following steps are implemented:

[0051] Step 1: Place the detection probe into the elbow 9 to be tested.

[0052] Turn on the controller 8, turn on the power, the lighting lamp 3 automatically lights up, and observe from the screen whether the probe reaches the predetermined position;

[0053] Step 2. After reaching the predetermined position, adjust the probe posture through the direction control key 6, try to keep it parallel to the cross section, then click the multi-function button 7 to call out the start detection unit, and calibrate the data center (the center of the data section circle) at the same time. The displacement sensor array 2 controls the sensor retractable probe 4 to move in sequence to read the diameter data of the entire cross section.

[0054] Click the multi-function button 7 to call up the analysis unit, and draw a cross-sectional diagram of the displacement sensor data with the calibration data center as the center. In the diagram, select the maximum value of the inner and outer arc data, which is D1, and select the maximum value of the neutral surface data, which is D2.

[0055] The controller 8 uses the pre-stored calculation program, the nominal outer diameter Di=347mm of the elbow 9 to be tested, and the two radial diameter values ​​D1=342mm and D2=357mm obtained by detection, to calculate the final value a=4.32% of the out-of-roundness of the elbow 9 to be tested;

[0056] After obtaining the calculation result, the controller 8 displays the value of the out-of-roundness a on the touch screen.

[0057] It can be seen that according to the detection method of the present invention, the overall deformation is determined to be within the allowable range, which fully meets the product quality requirements.

[0058] Example 2

[0059] The steps of Example 1 are the same as those of Example 2. Example 2 detects a 135° elbow of a steam branch pipe, made of T91 material, with a specification inner diameter Di of 213 mm. Macroscopic inspection reveals that the elbow is relatively flat. According to the specification, the out-of-roundness needs to be measured from the inside. The two radial diameter values ​​D1 = 205 mm and D2 = 223 mm are measured, and the final out-of-roundness value a of the elbow 9 to be inspected is calculated to be 8.45%;

[0060] It can be seen that according to the detection method of the present invention, if it is determined that the overall deformation exceeds the allowable range, it should be processed or monitored.

[0061] Example 3

[0062] The steps of Example 1 are the same as those of Example 3. Example 3 detects a 135° elbow of a steam branch pipe, made of T91 material, with a specification inner diameter Di of 213 mm. Macroscopic inspection reveals that the elbow is relatively flat. According to the specification, the out-of-roundness needs to be measured from the inside. The two radial diameter values ​​D1 = 205 mm and D2 = 215 mm are measured, and the final out-of-roundness value a of the elbow 9 to be inspected is calculated to be 4.69%;

[0063] It can be seen that according to the detection method of the present invention, the overall deformation is determined to be within the allowable range, which fully meets the product quality requirements.

Claims

1. A device for detecting the non-roundness of the inner section of a pipe elbow for a power plant, characterized in that: The invention comprises a detection unit, wherein the detection unit comprises an annular detection unit housing (1), the detection unit housing (1) is provided with evenly distributed holes, a displacement sensor array (2) is arranged at the center of the detection unit housing (1), the displacement sensor array (2) is connected to a controller (8) via a connecting line (5), the displacement sensor array (2) comprises a lighting lamp (3) arranged at the center, a circle of sensor retractable probes (4) are arranged around the lighting lamp (3), and the sensor retractable probes (4) are controlled by the controller (8) to retract in the holes on the detection unit housing (1) to adjust the position and posture of the detection unit housing (1) and measure diameter data.

2. The device for detecting the non-roundness of the inner section of the elbow of a power plant according to claim 1, characterized in that: The entire displacement sensor array (2) is fixed by means of hexagonal bolts (10).

3. The device for detecting the non-roundness of the inner section of the elbow of a power plant according to claim 1, characterized in that: The connecting line (5) is composed of a connecting cable, an optical fiber and a carbon fiber filament. The connecting cable is used for power supply. A camera is arranged at the end of the optical fiber for photographing the internal environment. The carbon fiber filament provides tension.

4. The device for detecting the non-roundness of the inner section of the elbow of a power plant according to claim 1, characterized in that: The controller (8) is pre-installed with an out-of-roundness calculation program, and the controller (8) is provided with a direction control key (6) and a multi-function button (7) for controlling and adjusting the position and posture of the entire displacement sensor array (2); The controller (8) is equipped with a touch screen display, and its functions are as follows: 1) The touch screen is provided with an on / off button for the displacement sensor array (2) and a window for displaying measurement data of the displacement sensor (2), and when the data in the window is clicked, the data is saved; 2) The power of the controller (8) is supplied by a rechargeable battery; 3) The touch screen is also provided with a button for starting calculation and a page for displaying the final result, which displays the final out-of-roundness value obtained through the calculation program.

5. A method for measuring the non-circularity of the inner section of a pipe elbow for a power plant, using the non-circularity detection device according to any one of claims 1 to 4, characterized in that: Follow these steps to implement: Step 1: Place the detection unit into the elbow to be detected (9), turn on the controller (8), turn on the machine, and the lighting lamp (3) automatically lights up. The controller (8) adjusts the position of the detection unit, and observes whether the detection unit reaches the predetermined position through the touch display screen; Step 2, when the detection unit reaches the predetermined position, the probe posture is adjusted by the direction control key (6) to keep it parallel to the cross section of the elbow (9) to be detected, and then the multi-function button (7) is clicked to call up the start detection unit, and the data center, that is, the center of the data cross section, that is, the actual measured center of the cross section, is calibrated at the same time, and the controller (8) controls the sensor retractable probe (4) to retract in sequence to read the diameter data of the entire cross section; Step 3, click the multi-function button (7) to call up the analysis unit, and draw a cross-sectional diagram of the displacement sensor data with the calibration data center as the center. In the diagram, select the maximum value of the inner and outer arc data, which is D1, and select the maximum value of the neutral surface data, which is D2; Step 4, the controller (8) uses a pre-stored calculation program to calculate the final value a of the out-of-roundness of the elbow (9) to be tested according to the nominal outer diameter Di of the elbow (9) to be tested and the two radial diameter values ​​D1 and D2 obtained by detection; Step 5: After obtaining the calculation result, the controller (8) displays the value of the out-of-roundness a on the touch screen.

6. The device for detecting the non-roundness of the inner section of the elbow of a power plant according to claim 5, characterized in that: In step 1, the multifunctional button (7) is used to control the sensor's retractable probe (4) to extend two probes symmetrically 180° to clamp the detection unit, and then adjust the other direction until it is parallel to the cross section, and the detection unit reaches a predetermined position.

7. The device for detecting the non-roundness of the inner section of the elbow of a power plant according to claim 6, characterized in that: In step 2, two symmetrical 180° probes perpendicular to the first probe are excited in sequence, and then other probes are excited in sequence to read the diameter data of the entire cross section.

8. The device for detecting the non-roundness of the inner section of the elbow of a power plant according to claim 5, characterized in that: The out-of-roundness numerical detection of the elbow (9) to be tested in step 4 is specifically as follows: Assuming that the nominal inner diameter of the elbow (9) to be tested is Di, input Di, then the calculation formula for the out-of-roundness a is: a=(D2-D1)×100% / Di.

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