A device and method for measuring the inner wall temperature of a pipe based on a movable airbag

Abstract

The present invention discloses a device and method for measuring the temperature of the inner wall of a pipeline based on a movable airbag. The device includes: an inflatable support rod, located inside the pipeline, and having a plurality of inflation holes distributed thereon for supporting and inflating the airbag; the airbag, the center of which is fixed to the inflatable support rod, and through inflation, a glass fiber cloth is pressed against the pipeline wall surface, so that a thermocouple measuring point arranged between the glass fiber cloth and the pipeline is closely attached to a temperature measurement position on the inner wall of the pipeline; the glass fiber cloth, which has an opening at the bottom and a hole at the center of the top, covers the outside of the airbag, and a curable resin is permeated and distributed in the glass fiber cloth; a thermocouple, including a thermocouple measuring point and a thermocouple wire, wherein the thermocouple measuring point is adhered to a set position outside the glass fiber cloth and enters the pipeline together with the glass fiber cloth and the airbag, and the thermocouple wire is led out of the pipeline. The temperature measurement method is as follows: pre-fill the airbag with a certain amount of gas, ensuring that the airbag diameter is larger than the top hole diameter of the glass fiber cloth and smaller than the inner diameter of the pipe. Place the temperature measuring device in the pipe, aligning the thermocouple measuring point with the designated temperature measurement location. Then, inflate the airbag via the inflatable support rod to a matching pressure, ensuring that the glass fiber cloth covering the airbag is tightly attached to the inner wall of the pipe at the designated temperature measurement location. Press the thermocouple attached to the glass fiber cloth against the pipe wall, maintaining constant pressure in the airbag. Allow the resin in the glass fiber cloth to cure naturally until it is fully cured. The glass fiber cloth takes shape under the action of the resin, while the thermocouple remains pressed against the pipe wall. After the resin cures, deflate the airbag, reclaim the air, and complete the arrangement of the pipe wall temperature measuring points before measuring the pipe wall temperature.

Description

Technical Field

[0001] The present invention relates to a temperature measuring device and method for measuring the temperature of an inner wall of a pipeline, and in particular to a temperature measuring device and method for an inner wall of a pipeline based on a movable airbag. Background Art

[0002] In thermal fluid tests, especially heat transfer tests of steam generator casing assemblies, it is necessary to measure the temperature of the inner wall of the casing.

[0003] Chinese patent CN105784160A proposes a temperature measuring device and method for measuring the temperature of the inner wall of a pipeline, and is particularly concerned with measuring the temperature of the inner wall of a small-diameter pipeline. The inner wall temperature of a small-diameter pipeline is measured by a single thermocouple. The temperature measuring device can move freely in the narrow space defined by the inner wall of the pipeline to measure the temperature at any position of the inner wall. The temperature measuring end of the measuring device is pressed against the inner wall of the pipeline based on the elastic force of the elastic force applying part. The sleeve can be rotated to measure the temperature of the inner wall of the pipeline at different circumferential positions, and the sleeve can be moved parallel to the central axis of the pipeline to measure the temperature of another position of the inner wall of the pipeline. In addition, when the pipeline is electrically heated (for example, when the pipeline is an electric heating rod), the temperature measuring device can also ensure insulation. However, the device cannot measure the temperature of multiple positions on the inner wall surface at the same time. Chinese patent CN220170379U proposes a device that can measure the temperature of the inner wall of a pipeline in real time and from multiple angles. The inner wall limiter assembly, the measuring assembly, and the rotating rod work together to position the device at the inner wall of the pipe to be measured. The rotating rod drives the measuring assembly to rotate, enabling temperature measurements from multiple angles on the pipe's inner wall. However, this device cannot measure the temperature of multiple locations on the pipe's inner wall simultaneously and is not suitable for measuring the inner wall temperature of small-diameter pipes.

[0004] The temperature measuring device in the existing patent cannot measure the temperature of multiple axial points or multiple circumferential points at the same time; when measuring a variable diameter pipe, the entire device needs to be replaced, and the process is relatively complicated; and when measuring the temperature, there are mechanisms other than the temperature measuring thermocouple in the pipe, which occupy the space inside the pipe, making it impossible to install other measuring devices in the pipe. Summary of the Invention

[0005] In order to overcome the problems existing in the above-mentioned prior art, the purpose of the present invention is to provide a pipe inner wall temperature measuring device and method based on a movable airbag. The pipe inner wall temperature measuring device is composed of an inflatable support rod, an airbag, a glass fiber cloth and a thermocouple, and can realize multi-point synchronous temperature measurement of the inner wall of a variable-diameter pipe with adjustable radial, axial and circumferential positions and adjustable number of measuring points; at the same time, through the pipe inner wall temperature measurement method based on the aforementioned device, temperature measurement without additional mechanism in the pipeline is realized.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A pipe inner wall temperature measuring device based on a movable airbag, comprising:

[0008] The inflatable support rod 1 is located inside the pipe and has a plurality of inflatable holes 5 distributed thereon for supporting and inflating the airbag 4;

[0009] There are one or more airbags 4, the center of which is fixed on the inflatable support rod 1. The glass fiber cloth is pressed against the inner wall of the pipe by inflation, so that the thermocouple measuring point arranged between the glass fiber cloth and the pipe is closely attached to the temperature measurement position of the inner wall of the pipe;

[0010] One or more glass fiber cloths 6 are provided, covering the corresponding airbags 4. The diameter of the glass fiber cloths 6 is equal to the diameter of the pipe section to be measured, and the glass fiber cloths 6 are suspended and supported on the airbags 4. The glass fiber cloths 6 contain a curable resin. When the airbags 4 are inflated, the glass fiber cloths 6 expand under the action of the airbags 4 and cling to the inner wall of the pipe, maintaining the pressure in the airbags constant. After a period of time, the resin naturally solidifies, the glass fiber cloths are set, and the thermocouple measuring points are pressed against the inner wall of the pipe.

[0011] The thermocouple is one or more, including a thermocouple measuring point 2 and a thermocouple wire 3. One or more thermocouple measuring points 2 are fixed at a set position outside the glass fiber cloth 6, and enter the pipeline together with the glass fiber cloth 6 and the air bag 4. The thermocouple wire 3 is led out from the pipeline.

[0012] The curable resin is selected from high temperature resistant epoxy resin, which is infiltrated and distributed in the glass fiber cloth 6 by a doctor blade coating method.

[0013] When the pipe to be temperature-measured is an energized pipe, the inflatable support rod 1 is made of a rigid insulating material, and the airbag 4 is made of an insulating material.

[0014] The pipe to be temperature measured is a pipe of constant diameter or a pipe of variable diameter. When the pipe to be temperature measured is a pipe of variable diameter, the shape of the glass fiber cloth 6 is changed to a shape matching the pipe of variable diameter, such as a truncated cone.

[0015] A hole with a diameter larger than the diameter of the airbag 4 in an uninflated state and smaller than the inner diameter of the pipe 7 is opened in the center of the top of the glass fiber cloth 6 .

[0016] A method for measuring the inner wall temperature of a pipe based on a movable airbag, using the aforementioned temperature measuring device; the details are as follows:

[0017] A certain amount of gas is pre-filled into the airbag 4 to ensure that the diameter of the airbag 4 is larger than the top hole diameter of the glass fiber cloth 6 and smaller than the inner diameter of the pipe, so as to prevent the glass fiber cloth 6 from falling off the airbag 4 and ensure that the airbag 4, the glass fiber cloth 6 and the thermocouple can be extended into the interior of the pipe 7 to be measured together with the inflatable support rod 1; the temperature measuring device is extended into the pipe 7, and after the thermocouple is located at the designated temperature measuring position, the airbag 4 is inflated through the inflatable holes 5 distributed on the inflatable support rod 1, and the matching pressure is reached, so that the glass fiber cloth 6 covering the outside of the airbag 4 is tightly pressed against the glass fiber cloth 6. Closely adhere to the inner side of the pipe wall at the designated temperature measurement position, maintain the pressure in the airbag unchanged, and wait for 1 to 3 days at room temperature until the curable resin in the glass fiber cloth is cured, and the glass fiber cloth 6 and the thermocouple measuring point 2 are fixed to the inner wall of the pipe; after the curable resin is cured, deflate the airbag 4 through the inflatable support rod 1 to shrink the diameter of the airbag 4 to a diameter smaller than the diameter of the small hole at the top of the glass fiber cloth 6, and then pull the airbag 4 and the inflatable support rod 1 out of the pipe 7 and recycle them. After completing the arrangement of the pipe inner wall temperature measuring points, measure the pipe inner wall temperature.

[0018] It is ensured that the curable resin in the glass fiber cloth 6 is in an uncured stage before the temperature measuring device is installed.

[0019] Compared with the prior art, the present invention has the following advantages:

[0020] 1) The present invention can realize temperature measurement in multiple axial temperature measurement sections. By arranging multiple air bags and glass fiber cloths along the axial direction as needed on the inflatable support rod, multiple circumferential temperature measurement sections can be arranged;

[0021] 2) The present invention can achieve circumferential multi-point temperature measurement by arranging multiple thermocouples at required positions on the circumference of the airbag and the glass fiber cloth;

[0022] 3) The present invention can realize the temperature measurement of the inner wall of various pipe diameters and the temperature measurement of multiple axial temperature measurement sections of variable diameter pipes. By changing the size and inflation volume of the airbag, the temperature of the inner wall of pipes with different inner diameters can be measured. At the same time, based on advantage (1), the temperature measurement of the inner wall of variable diameter pipes can be realized by changing the size and inflation volume of the airbag at different axial measurement points.

[0023] 4) The present invention can realize the arrangement of any number and position of temperature measuring points in any variable diameter pipeline. On the basis of the above advantages (1), (2) and (3), the number and position of measuring points in the three dimensions of the diameter (i.e., the radial position of the temperature measuring point), axial direction and circumferential direction of the variable diameter pipeline can be arranged and combined as needed to realize the arrangement of any number and position of temperature measuring points in variable diameter and non-variable diameter pipelines.

[0024] 5) The present invention can realize the temperature measurement of the inner wall of the pipeline without external mechanisms. After the temperature measurement points are arranged, the cured glass fiber cloth is tightly attached to the pipeline wall. The airbag and the inflatable support rod are withdrawn from the pipeline, leaving only the wall thermocouple and the glass fiber cloth. Other required devices can be arranged in the pipeline. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a cross-sectional schematic diagram of the pipeline inner wall temperature measuring device based on the movable airbag of the present invention before installation when entering the interior of the pipeline.

[0026] Figure 2 It is a cross-sectional schematic diagram of the pipe inner wall temperature measuring device based on the movable airbag during inflation and solidification of the present invention.

[0027] Figure 3 This is a cross-sectional schematic diagram of the pipe inner wall temperature measuring device based on the movable airbag of the present invention when the airbag and the inflatable support rod are recovered after the glass fiber cloth is cured.

[0028] Figure 4 This is a cross-sectional schematic diagram of the pipe inner wall temperature measuring device based on the movable airbag of the present invention when temperature measurement is started after installation is completed.

[0029] Figure 5 The figure is a cross-sectional schematic diagram of a pipe inner wall temperature measuring device based on a movable airbag according to an embodiment of the present invention for measuring the temperature of multiple axial sections of the inner wall of a pipe.

[0030] Figure 6 The present invention is a cross-sectional schematic diagram of a pipe inner wall temperature measuring device based on a movable airbag measuring the temperature at different diameters of the inner wall of straight pipes or variable diameter pipes of different inner diameters according to an embodiment of the present invention.

[0031] Figure 7 This is a top view of a pipe inner wall temperature measuring device based on a movable airbag according to an embodiment of the present invention measuring the temperature of multiple measuring points along the circumference of the pipe inner wall.

[0032] Among them, 1-inflatable support rod, 2-thermocouple measuring point, 3-thermocouple wire, 4-air bag, 5-inflatable hole, 6-glass fiber cloth, 7-pipeline. DETAILED DESCRIPTION

[0033] The technical solution of the present invention is further described in detail below through embodiments and in conjunction with the accompanying drawings.

[0034] A temperature measuring device for measuring the temperature of an inner wall of a pipe according to an exemplary embodiment of the present invention is described below.

[0035] like Figure 1 、 Figure 2 、 Figure 3 and Figure 4As shown, a pipe inner wall temperature measuring device based on a movable airbag is used to measure the inner wall temperature of a pipe 7, comprising: an inflatable support rod 1, located inside the pipe 7, and having a plurality of inflatable holes 5 distributed thereon, for supporting and inflating an airbag 4; the airbag 4, the center of which is fixed on the inflatable support rod 1, presses a glass fiber cloth 6 against the wall of the pipe 7 by inflating, so that a thermocouple measuring point 2 arranged between the glass fiber cloth 6 and the pipe 7 is closely attached to the temperature measuring position of the inner wall of the pipe 7; the glass fiber cloth 6 The bottom is open and a hole is opened in the center of the top with a diameter larger than the diameter of the airbag in an uninflated state and smaller than the inner diameter of the pipe, covering the outside of the airbag 4, and curable resin is infiltrated and distributed in the glass fiber cloth 6; the thermocouple includes a connected thermocouple measuring point 2 and a thermocouple wire 3, wherein the thermocouple measuring point 2 and the thermocouple wire 3 are both insulated, the thermocouple measuring point 2 is adhered to a set position outside the glass fiber cloth 6, and enters the pipe 7 together with the glass fiber cloth 6 and the airbag 4, and the thermocouple wire 3 is led out from the pipe 7.

[0036] A high-temperature resistant epoxy resin can be used as the curable resin. Using a scraper, apply the curable resin evenly to the contact surface of the glass fiber cloth 6 with the pipe 7. The relationship between the glass fiber cloth thickness and the amount of curable resin applied should ensure that the resin evenly and completely penetrates the glass fiber cloth 6 and does not penetrate between the glass fiber cloth 6 and the airbag 4. Under the action of the airbag 4, the glass fiber cloth 6 expands and adheres tightly to the inner wall of the pipe 7. Maintaining constant pressure within the airbag 4, the curable resin naturally solidifies over time, the glass fiber cloth takes shape, and the thermocouple measuring point 2 is pressed against the inner wall of the pipe 7.

[0037] Therefore, using the technical solution of the present invention, the above-mentioned temperature measuring device can be placed in the narrow inner cavity of the pipeline. By inflating the airbag 4 and sticking multiple thermocouple measuring points 2 on the glass fiber cloth 6, the temperature of multiple positions on the inner wall of the pipeline 7 can be measured simultaneously.

[0038] During the process of placing the above-mentioned temperature measuring device into the pipeline, a certain amount of gas is pre-filled into the airbag 4 to ensure that the diameter of the airbag 4 is larger than the top hole diameter of the glass fiber cloth and smaller than the inner diameter of the pipeline to prevent the glass fiber cloth from falling off and ensure that the glass fiber cloth enters the pipeline together with the airbag and the inflatable support rod.

[0039] like Figure 5 As shown, it includes multiple glass fiber cloths 6 and corresponding thermocouples, which are arranged along the axial direction of the pipeline. The curable resin in the glass fiber cloth has been cured and shaped, and the thermocouple measuring point 2 is pressed against the pipe wall, which can realize temperature measurement of different axial sections.

[0040] like Figure 6As shown, it includes multiple unequal diameter glass fiber cloths 6 and corresponding thermocouples, which are axially arranged in a variable diameter pipe 7, wherein the curable resin in the glass fiber cloth 6 has been cured and shaped, and the thermocouple measuring point 2 is pressed against the pipe wall, which can realize the temperature measurement of different axial sections of the variable diameter pipe.

[0041] like Figure 7 As shown, it includes a glass fiber cloth 6 and multiple thermocouples arranged along the circumferential direction. Multiple thermocouple measuring points 2 are pasted on the same glass fiber cloth 6, which can realize temperature measurement at different circumferential positions.

[0042] It should be specially pointed out that when measuring the temperature of the inner wall of a non-electrically heated pipe, since there is no need for electrical insulation, the inflatable support rod 1 and the airbag 4 may also be non-insulated.

[0043] The method for measuring the inner wall temperature of a pipe by a measuring device of the present invention comprises extending the pipe inner wall temperature measuring device into a pipe 7, inflating the airbag 4 through the inflation holes 5 distributed on the inflation support rod 1, and reaching a matching pressure, so that the glass fiber cloth 6 covering the outside of the airbag 4 is tightly attached to the inner side of the pipe wall 7 at the measuring point position, maintaining the pressure in the airbag 4 unchanged, waiting for 1 to 3 days at room temperature until the resin in the glass fiber cloth 6 is cured, and the glass fiber cloth 6 and the thermocouple measuring point 2 are fixed on the inner wall of the pipe 7. After the curable resin is cured, the airbag 4 is deflated through the inflation support rod 1, so that the diameter of the airbag 4 is shrunk to be smaller than the diameter of the top hole of the glass fiber cloth 6, the airbag 4 and the inflation support rod 1 are pulled out of the pipe 7 and recovered, and the pipe inner wall temperature is measured after the arrangement of the pipe 7 inner wall temperature measuring points is completed.

Claims

1. A pipe inner wall temperature measuring device based on a movable airbag, characterized in that: include: An inflatable support rod (1) is located inside the pipe and has a plurality of inflatable holes (5) distributed thereon for supporting the airbag (4) and inflating the airbag (4); The airbag (4) is one or more, the center of which is fixed on the inflatable support rod (1), and the glass fiber cloth is pressed against the inner wall of the pipe by inflation, so that the thermocouple measuring point arranged between the glass fiber cloth and the pipe is closely attached to the temperature measuring position of the inner wall of the pipe; One or more glass fiber cloths (6) are covered on the outside of the corresponding airbags (4), have a diameter equal to the diameter of the pipe section to be measured, are open at the bottom and have a hole in the center of the top, and are used to suspend and support the glass fiber cloth (6) on the airbags (4). The glass fiber cloth (6) contains a curable resin; when the airbags (4) are inflated, the glass fiber cloth (6) expands under the action of the airbags (4) and adheres to the inner wall of the pipe, maintaining the pressure in the airbags unchanged until the resin naturally solidifies after a period of time, the glass fiber cloth is shaped, and the thermocouple measuring point is pressed against the inner wall of the pipe; The thermocouple is one or more and includes a thermocouple measuring point (2) and a thermocouple wire (3). The one or more thermocouple measuring points (2) are fixed at a set position outside the glass fiber cloth (6) and enter the pipeline together with the glass fiber cloth (6) and the air bag (4). The thermocouple wire (3) is led out from the pipeline.

2. The pipe inner wall temperature measuring device based on a movable airbag according to claim 1 is characterized in that: The curable resin is selected from high-temperature resistant epoxy resin, which is infiltrated and distributed in the glass fiber cloth (6) by a scraping method.

3. The pipe inner wall temperature measuring device based on a movable airbag according to claim 1 is characterized in that: When the pipe to be temperature-measured is an electrified pipe, the inflatable support rod (1) is made of a rigid insulating material, and the airbag (4) is made of an insulating material.

4. The pipe inner wall temperature measuring device based on a movable airbag according to claim 1 is characterized in that: The pipe to be temperature-measured is a pipe of constant diameter or a pipe of variable diameter. When the pipe to be temperature-measured is a pipe of variable diameter, the shape of the glass fiber cloth (6) is changed to a shape matching the pipe of variable diameter.

5. The pipe inner wall temperature measuring device based on a movable airbag according to claim 1 is characterized in that: A hole with a diameter larger than the diameter of the air bag in an uninflated state and smaller than the inner diameter of the pipe is opened in the center of the top of the glass fiber cloth (6).

6. A method for measuring the inner wall temperature of a pipe based on a movable airbag, characterized in that: A temperature measuring device according to any one of claims 1 to 5 is used; specifically: A certain amount of gas is pre-filled into the airbag (4) to ensure that the diameter of the airbag (4) is larger than the top hole diameter of the glass fiber cloth (6) and smaller than the inner diameter of the pipe, so as to prevent the glass fiber cloth (6) from falling off the airbag (4) and ensure that the airbag (4), the glass fiber cloth (6) and the thermocouple can be extended into the pipe (7) to be measured together with the inflation support rod (1); the temperature measuring device is extended into the pipe (7), and after the thermocouple is located at the designated temperature measurement position, the airbag (4) is inflated through the inflation holes (5) distributed on the inflation support rod (1) to reach a matching pressure, so that the glass fiber cloth covering the outside of the airbag (4) is The fiberglass cloth (6) is tightly attached to the inner side of the pipe wall at the designated temperature measurement position, and the pressure in the airbag is kept constant. The temperature is kept constant for 1 to 3 days at room temperature until the curable resin in the fiberglass cloth is cured, and the fiberglass cloth (6) and the thermocouple measuring point (2) are fixed on the inner wall of the pipe. After the curable resin is cured, the airbag (4) is deflated through the inflatable support rod (1) to shrink the diameter of the airbag (4) to a diameter smaller than the diameter of the small hole at the top of the fiberglass cloth (6). The airbag (4) and the inflatable support rod (1) are extracted from the pipe (7) and recovered. After the arrangement of the pipe inner wall temperature measuring points is completed, the pipe inner wall temperature is measured.

7. The method for measuring the inner wall temperature of a pipe based on a movable airbag according to claim 6, characterized in that: Ensure that the curable resin in the glass fiber cloth (6) is in an uncured stage before the temperature measuring device is installed.

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