Thin-walled hollow circular tube inner wall temperature calibration measurement device and method

Abstract

The present invention relates to a device and method for calibrating and measuring the inner wall temperature of a thin-walled hollow circular tube, and belongs to the technical field of high-temperature mechanical properties testing of high-temperature structural materials. The purpose is to solve the technical problem that the internal cooling gas and the temperature measuring device of the thin-walled hollow circular tube under high temperature conditions do not interfere with each other, so as to achieve accurate measurement of the inner wall temperature of the thin-walled hollow circular tube through which the cooling gas passes. By assembling the working thermocouple, the thermocouple cover plate, the positioning pins and the calibration thermocouple on the calibration specimen, a calibration test of passing cooling gas under high temperature conditions is carried out, so as to obtain a temperature response comparison diagram of the calibration thermocouple and the working thermocouple. According to the test task requirements, the external applied temperature and the inner wall temperature of the test piece are determined, and the temperature response comparison diagram of the corresponding calibration thermocouple and the working thermocouple is consulted. By controlling and fine-tuning the cooling gas pressure and flow rate of the air compressor, a heating method with a specified temperature gradient can be realized on the test piece.

Description

Technical Field

[0001] The present invention relates to the technical field of high-temperature mechanical properties testing of high-temperature structural materials, and specifically provides a device and method for calibrating and measuring the inner wall temperature of a thin-walled hollow circular tube, which is suitable for comprehensive mechanical properties testing of aviation engine turbine component materials under temperature gradient conditions. Background Art

[0002] Core components of modern advanced aircraft engines, such as turbine blades and disks, typically utilize gas cooling technology to maintain their operating temperature. This temperature reduction effectively improves the operating environment of the blades and disks, enhancing their strength and extending their service life. Gas cooling technology plays a crucial role in the development and production of high-performance aircraft engines both domestically and internationally. Generally speaking, gas cooling creates a temperature gradient between the surface and interior of the blades and disks. Domestic and international literature indicates that the failure mechanisms and mechanical properties of metal materials differ under conditions of uniform temperature and temperature gradients. To fully understand and master the failure mechanisms and mechanical properties of turbine blades and disks under temperature gradient conditions, domestic and international researchers typically conduct comprehensive mechanical property testing and analysis of turbine blade and disk materials, including static, fatigue, endurance, and creep tests, in the laboratory using thin-walled hollow tubes with cooling gas flowing through them. Thin-walled hollow circular tubes have the advantages of high heating efficiency, more uniform temperature and less required materials. However, they also have disadvantages such as complex processing technology and difficulty in accurately measuring the inner wall temperature. Especially after cooling gas passes through the inside of the thin-walled hollow circular tube, it is difficult to effectively determine the inner wall temperature due to the dual constraints of the narrow diameter of the thin-walled hollow circular tube and the long sample, as well as the inability to install auxiliary temperature measuring devices inside the thin-walled hollow circular tube that affect the uniform flow of cooling gas.

[0003] Invention patent CN 105157864A, "Method for Measuring the Inner Wall Temperature of a Hollow Circular Rod Specimen," proposes a method for measuring temperature using a spring sheet arc-shaped surface welded to a thermocouple in close contact with the inner wall of a hollow circular rod specimen. Invention patent CN 111707390A, "A Multi-point Temperature Measuring Rod for the Inner Wall of a Hollow Circular Tube Specimen and Its Temperature Measurement Method," proposes a method for measuring the inner wall temperature of a hollow circular tube specimen by combining multiple spring sheets with temperature measuring elements to achieve multi-point contact on the inner wall of the hollow circular tube specimen. The technical implementation approach of invention patent CN 111707390A is similar to that of invention patent CN 105157864A, with the primary difference being the number of temperature points on the inner wall of the hollow circular tube specimen. Although the above measurement method can accurately determine the inner wall temperature of a hollow circular rod specimen, it is not suitable for measuring the inner wall temperature of thin-walled hollow circular tubes through which cooling gas passes. This is because the longer spring sheet will interfere with the stable flow of the cooling gas within the pipe diameter, and the distribution of the cooling gas on a specific cross-section within the pipe diameter is not uniform, which easily leads to technical difficulties that affect the accurate measurement of the inner wall temperature due to inconsistent cooling effects. Invention patent CN108507864B "A method for obtaining the temperature gradient in the wall thickness direction of the test piece test section in a TGMF test" proposes a test method for assembling and connecting a hollow circular tube specimen with a test machine fixture and an air compressor. It adopts temperature cycling and conducts ventilation tests under zero stress conditions. With the help of finite element software, fluid-solid coupling calculations are performed to obtain the temperature gradient in the wall thickness direction of the test section. This measurement method requires the use of fluid-solid coupling finite element simulation technology to determine the temperature gradient in the wall thickness direction of the test section. Since fluid-solid coupling finite element simulation technology requires accurate boundary conditions and physical parameters to obtain reasonable test results, in reality, the airflow state in the slender hollow circular tube is very complex, and the boundary conditions of the inlet and outlet airflow and the physical parameters of the gas are difficult to obtain accurately, which easily causes the accuracy of the fluid-solid coupling finite element simulation to decrease, and the temperature gradient in the wall thickness direction of the test section of the hollow circular tube specimen cannot be accurately determined. Summary of the Invention

[0004] The purpose of the present invention is to solve the technical problems that the cooling gas and the temperature measuring device inside the thin-walled hollow circular tube do not interfere with each other under high temperature conditions and the fluid-solid coupling finite element simulation technology is difficult to obtain accurate results, thereby realizing the accurate measurement of the inner wall temperature of the thin-walled hollow circular tube.

[0005] The technical solution of the present invention is:

[0006] A device for calibrating and measuring the inner wall temperature of a thin-walled hollow circular tube is provided. The thickness of the thin-walled hollow circular tube is ≤2 mm. A calibration specimen is used in the calibration measurement method. The middle of the calibration specimen is a thin-walled hollow circular tube 100, and the two ends of the calibration specimen are circular tube mounting ends 101; the center of the calibration specimen is a continuous and smooth hollow circular tube cavity 102; at least one circular tube mounting end 101 is provided with a temperature measuring hole 103, and the temperature measuring hole 103 is used to measure the tube cavity temperature of the corresponding circular tube mounting end 101.

[0007] The thin-walled hollow circular tube 100 is provided with a stepped through hole 104 . The upper opening of the stepped through hole 104 is gradually expanding and has a non-circular shape. A plurality of pin holes 105 are provided on the stepped surface of the stepped through hole 104 .

[0008] The stepped through hole 104 is matched with a cover plate, which is a boss structure and matches the shape of the stepped through hole 104; the outer surface 106 of the cover plate is a cylindrical surface, forming a continuous surface with the outer surface of the thin-walled hollow circular tube 100, and the inner surface 107 of the cover plate is a cylindrical surface, forming a continuous surface with the inner wall surface of the thin-walled hollow circular tube 100; the cover plate is provided with a plurality of pin holes 108, and the pin holes 108 of the cover plate correspond one-to-one with the pin holes 105 of the stepped through hole 104, and fixing pins 109 are inserted into the corresponding pin holes 108 of the cover plate and the pin holes 105 of the stepped through hole 104; the shape of the outer edge of the cover plate is the same as the shape of the upper opening of the stepped through hole 104 to ensure position alignment.

[0009] The cover plate is provided with a thermocouple lead hole 110 , into which a thermocouple can be embedded, so that the thermocouple can measure the lumen temperature of the corresponding thin-walled hollow circular tube 100 .

[0010] Furthermore, the stepped through hole 104 is machined by a micro-EDM method.

[0011] Furthermore, the pin hole 108 of the cover plate and the pin hole 105 of the stepped through hole 104 are both provided with a keyway 111, and the fixing pin 109 is provided with a convex key 112 to form a shape fit to prevent incorrect insertion.

[0012] Furthermore, the pin hole 105 of the stepped through hole 104 is a blind hole.

[0013] Furthermore, the gap between the mating surfaces of the stepped through hole 103 and the cover plate does not exceed 0.1 mm.

[0014] Furthermore, the calibration specimen is a high-temperature alloy.

[0015] A calibration method for the thin-walled hollow circular tube inner wall temperature calibration and measurement device is provided, comprising the following steps:

[0016] Step 1: Install the thin-walled hollow circular tube 100 inner wall temperature calibration and measurement device in a high-temperature environment, and introduce cooling gas into one of the circular tube installation ends 101.

[0017] Step 2: Under the high temperature environment temperature T0, the pressure p of the cooling gas is changed multiple times, and the cavity temperature T2 of the corresponding thin-walled hollow circular tube 100 and the cavity temperature T1 of the circular tube installation end 101 are simultaneously measured.

[0018] Step 3: According to the variation law of the pressure p of the cooling gas, a corresponding relationship between the tube cavity temperature T2 of the thin-walled hollow circular tube 100 and the tube cavity temperature T1 of the circular tube installation end 101 is established.

[0019] Furthermore, based on the changing law of the pressure p of the cooling gas and the corresponding relationship between the tube cavity temperature T2 of the thin-walled hollow circular tube 100 and the tube cavity temperature T1 of the circular tube mounting end 101, the tube cavity temperature T2 of the thin-walled hollow circular tube 100 corresponding to a specific tube cavity temperature T1 of the circular tube mounting end 101 can also be obtained by interpolation calculation.

[0020] A calibration method for the thin-walled hollow circular tube inner wall temperature calibration and measurement device is provided, comprising the following steps:

[0021] Step 1: Install the thin-walled hollow circular tube 100 inner wall temperature calibration and measurement device in a high temperature environment, and introduce cooling gas into one of the circular tube installation ends 101;

[0022] Step 2: While keeping the pressure p of the cooling gas constant, change the temperature T0 of the high-temperature environment multiple times, and simultaneously measure the corresponding lumen temperature T2 of the thin-walled hollow circular tube 100 and the lumen temperature T1 of the circular tube mounting end 101;

[0023] Step 3: According to the variation rule of the temperature T0 of the high temperature environment, a corresponding relationship between the lumen temperature T2 of the thin-walled hollow circular tube 100 and the lumen temperature T1 of the circular tube installation end 101 is established.

[0024] Furthermore, according to the changing law of the temperature T0 of the high-temperature environment and the corresponding relationship between the tube cavity temperature T2 of the thin-walled hollow circular tube 100 and the tube cavity temperature T1 of the circular tube mounting end 101, the tube cavity temperature T1 of any circular tube mounting end 101 corresponding to the tube cavity temperature T2 of the thin-walled hollow circular tube 100 can also be obtained by interpolation calculation.

[0025] Using the above calibration method, the test method for measuring the temperature of the inner cavity of a thin-walled hollow circular tube includes the following steps:

[0026] Step 1: Install the test piece in a high-temperature environment. The middle of the test piece is a thin-walled hollow circular tube 113, and the two ends of the test piece are circular tube mounting ends 114. The center of the test piece is a continuous and smooth hollow circular tube cavity 115. At least one circular tube mounting end is provided with a temperature measuring hole 116, and the temperature measuring hole 116 is used to measure the tube cavity temperature T1 of the corresponding circular tube mounting end 114. Cooling gas is introduced into one circular tube mounting end 114. The position of the temperature measuring hole 116 of the circular tube mounting end 114 of the test piece is the same as the position of the temperature measuring hole 103 of the circular tube mounting end 101 of the calibration test piece.

[0027] Step 2: Obtain the real-time lumen temperature T1 of the circular tube mounting end 114 through the temperature measuring hole 116;

[0028] Step 3: Using the tube cavity temperature T1 of the circular tube mounting end 114 measured in step 2 and the corresponding relationship, obtain the corresponding tube cavity temperature T2 of the thin-walled hollow circular tube 113 .

[0029] The advantages of the present invention are: the present invention can effectively overcome the shortcomings of the background technology: using a calibration specimen to measure the inner wall temperature of a thin-walled hollow circular tube, there is no need to weld thermocouples on the inner wall of the specimen or use other technologies to fix the thermocouples on the inner wall of the specimen, which effectively solves the traditional technical difficulties of welding thermocouples inside slender thin-walled hollow circular tubes. At the same time, it also successfully solves the technical difficulties of using other technologies to install thermocouples and their auxiliary temperature measuring devices to disturb the uniform distribution of cooling gas inside the thin-walled hollow circular tube and the difficulty in obtaining accurate results using fluid-solid coupling finite element simulation technology, thereby improving the measurement accuracy of the inner wall temperature of the thin-walled hollow circular tube.

[0030] 2. This indirect measurement method of the inner wall temperature of a thin-walled hollow circular tube passing cooling gas avoids the need to install thermocouples on the inner wall of the gauge section of the test piece. On the one hand, it solves the traditional technical difficulty of installing thermocouples inside slender thin-walled hollow circular tubes. On the other hand, it also eliminates the disturbance of the uniform distribution of cooling gas inside the thin-walled hollow circular tube caused by the installation of thermocouples and their accessories, thereby improving the measurement accuracy of the inner wall temperature of the thin-walled hollow circular tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a schematic diagram of the calibration specimen structure;

[0032] Figure 2 is a schematic diagram of the step hole structure;

[0033] Figure 3 Schematic diagram of the cover structure;

[0034] Figure 4 2. It is a schematic diagram of the fixed pin structure;

[0035] Figure 5 is a schematic diagram of the test piece structure;

[0036] Figure 6 This is a schematic diagram of the relationship between the tube cavity temperature T1 at the installation end of the circular tube and the corresponding thin-walled hollow circular tube cavity temperature T2;

[0037] Among them: 100 - thin-walled hollow circular tube, 101 - circular tube mounting end, 102 - hollow circular tube cavity, 103 - temperature measuring hole, 104 - stepped through hole, 105 - pin hole, 106 - outer surface of cover plate, 107 - inner surface of cover plate, 108 - pin hole, 109 - fixing pin, 110 - thermocouple lead hole, 111 - keyway, 112 - convex key, 113 - thin-walled hollow circular tube, 114 - circular tube mounting end, 115 - hollow circular tube cavity, 116 - temperature measuring hole. DETAILED DESCRIPTION

[0038] The disclosed examples will be described more fully with reference to the accompanying drawings, in which some (but not all) of the disclosed examples are shown. In fact, many different examples can be described and these examples should not be construed as limited to the examples set forth herein. Instead, these examples are described so that this disclosure will be thorough and complete and will fully convey the scope of the disclosure to those skilled in the art.

[0039] Example 1 provides a device for calibrating and measuring the inner wall temperature of a thin-walled hollow circular tube. The thickness of the thin-walled hollow circular tube is ≤2 mm. A calibration specimen is used in the calibration measurement method. The center of the calibration specimen is a thin-walled hollow circular tube 100, and the two ends of the calibration specimen are circular tube mounting ends 101. The center of the calibration specimen is a continuous and smooth hollow circular tube lumen 102. At least one circular tube mounting end is provided with a temperature measuring hole 103, and the temperature measuring hole 103 is used to measure the tube lumen temperature corresponding to the circular tube mounting end 101.

[0040] The thin-walled hollow circular tube 100 is provided with a stepped through hole 104. The upper opening of the stepped through hole 104 is gradually expanded and has a non-circular shape. The stepped surface of the stepped through hole 104 is provided with a plurality of pin holes 105.

[0041] The stepped through hole 104 is matched with a cover plate, which is a boss structure and matches the shape of the stepped through hole 104; the outer surface 106 of the cover plate is a cylindrical surface, forming a continuous surface with the outer surface of the thin-walled hollow circular tube 100, and the inner surface 107 of the cover plate is a cylindrical surface, forming a continuous surface with the inner wall surface of the thin-walled hollow circular tube 100; the cover plate is provided with a plurality of pin holes 108, and the pin holes 108 of the cover plate correspond one-to-one with the pin holes 105 of the stepped through hole 104, and fixing pins 109 are inserted into the pin holes 108 of the corresponding cover plate and the pin holes 105 of the stepped through hole 104; the shape of the outer edge of the cover plate is the same as the shape of the upper opening of the stepped through hole 104 to ensure position alignment;

[0042] The cover plate is provided with a thermocouple lead hole 110 , into which a thermocouple can be embedded, so that the thermocouple can measure the lumen temperature of the corresponding thin-walled hollow circular tube 100 .

[0043] The stepped through hole 104 is machined by a micro-EDM method.

[0044] The pin hole 108 of the cover plate and the pin hole 105 of the stepped through hole 104 are both provided with a keyway 111 , and the fixing pin 109 is provided with a convex key 112 to form a shape fit to prevent incorrect insertion.

[0045] The pin hole 105 of the stepped through hole 104 is a blind hole.

[0046] The clearance between the mating surfaces of the stepped through hole 103 and the cover plate does not exceed 0.1 mm.

[0047] The calibration specimen is a high-temperature alloy.

[0048] A calibration method for the thin-walled hollow circular tube inner wall temperature calibration and measurement device is provided, comprising the following steps:

[0049] Step 1: Install the thin-walled hollow circular tube 100 inner wall temperature calibration and measurement device in a high temperature environment of 1000° C., and introduce cooling gas into one of the circular tube installation ends 101;

[0050] Step 2: In a high-temperature environment of 1000°C, the cooling gas pressure p was varied multiple times (to 0.2 MPa, 0.4 MPa, and 0.6 MPa), and the corresponding lumen temperature T2 of the thin-walled hollow circular tube 100 (952°C, 940°C, and 932°C) and the lumen temperature T1 of the circular tube mounting end 101 (688°C, 679°C, and 674°C) were simultaneously measured.

[0051] Step 3: According to the variation law of the pressure p of the cooling gas, a corresponding relationship between the tube cavity temperature T2 of the thin-walled hollow circular tube 100 and the tube cavity temperature T1 of the circular tube installation end 101 is established.

[0052] According to the changing law of the pressure p of the cooling gas and the corresponding relationship between the tube cavity temperature T2 of the thin-walled hollow circular tube 100 and the tube cavity temperature T1 of the circular tube mounting end 101, the tube cavity temperature T2 of the thin-walled hollow circular tube 100 corresponding to a specific tube cavity temperature T1 of the circular tube mounting end 101 can also be obtained by interpolation calculation.

[0053] Using the above calibration method, the test method for measuring the temperature of the inner cavity of a thin-walled hollow circular tube includes the following steps:

[0054] Step 1: Install the test piece in a high-temperature environment of 1000°C. The middle of the test piece is a thin-walled hollow circular tube 113, and the two ends of the test piece are circular tube mounting ends 114. The center of the test piece is a continuous and smooth hollow circular tube cavity 115. At least one circular tube mounting end is provided with a temperature measuring hole 116, and the temperature measuring hole 116 is used to measure the tube cavity temperature T1 of the corresponding circular tube mounting end 114. Cooling gas is introduced into one circular tube mounting end 114. The position of the temperature measuring hole 116 of the circular tube mounting end 114 of the test piece is the same as the position of the temperature measuring hole 103 of the circular tube mounting end 101 of the calibration test piece.

[0055] Step 2: The real-time tube cavity temperature T1 of the round tube installation end 114 is obtained through the temperature measuring hole 116 and is 688° C.

[0056] Step 3: Based on the tube cavity temperature T1 of the circular tube mounting end 114 measured in step 2 and the corresponding relationship, the corresponding tube cavity temperature T2 of the thin-walled hollow circular tube 113 is obtained to be 952°C. It is also possible to obtain the tube cavity temperature T2 of the thin-walled hollow circular tube 100 (approximately 946°C) corresponding to a specific tube cavity temperature T1 (for example, 683.5°C) of the circular tube mounting end 101 through interpolation calculation.

[0057] Example 2 provides a device for calibrating and measuring the inner wall temperature of a thin-walled hollow circular tube. The thickness of the thin-walled hollow circular tube is ≤2 mm. A calibration specimen is used in the calibration measurement method. The center of the calibration specimen is a thin-walled hollow circular tube 100, and the two ends of the calibration specimen are circular tube mounting ends 101. The center of the calibration specimen is a continuous and smooth hollow circular tube lumen 102. At least one circular tube mounting end is provided with a temperature measuring hole 103, and the temperature measuring hole 103 is used to measure the lumen temperature of the corresponding circular tube mounting end 101.

[0058] The thin-walled hollow circular tube 100 is provided with a stepped through hole 104. The upper opening of the stepped through hole 104 is gradually expanded and has a non-circular shape. The stepped surface of the stepped through hole 104 is provided with a plurality of pin holes 105.

[0059] The stepped through hole 104 is matched with a cover plate, which is a boss structure and matches the shape of the stepped through hole 104; the outer surface 106 of the cover plate is a cylindrical surface, forming a continuous surface with the outer surface of the thin-walled hollow circular tube 100, and the inner surface 107 of the cover plate is a cylindrical surface, forming a continuous surface with the inner wall surface of the thin-walled hollow circular tube 100; the cover plate is provided with a plurality of pin holes 108, and the pin holes 108 of the cover plate correspond one-to-one with the pin holes 105 of the stepped through hole 104, and fixing pins 109 are inserted into the pin holes 108 of the corresponding cover plate and the pin holes 105 of the stepped through hole 104; the shape of the outer edge of the cover plate is the same as the shape of the upper opening of the stepped through hole 104 to ensure position alignment;

[0060] The cover plate is provided with a thermocouple lead hole 110 , into which a thermocouple can be embedded, so that the thermocouple can measure the lumen temperature of the corresponding thin-walled hollow circular tube 100 .

[0061] The stepped through hole 104 is machined by a micro-EDM method.

[0062] The pin hole 108 of the cover plate and the pin hole 105 of the stepped through hole 104 are both provided with a keyway 111 , and the fixing pin 109 is provided with a convex key 112 to form a shape fit to prevent incorrect insertion.

[0063] The pin hole 105 of the stepped through hole 104 is a blind hole.

[0064] The clearance between the mating surfaces of the stepped through hole 103 and the cover plate does not exceed 0.1 mm.

[0065] The calibration specimen is a high-temperature alloy.

[0066] A calibration method for the thin-walled hollow circular tube inner wall temperature calibration and measurement device is provided, comprising the following steps:

[0067] Step 1: Install the thin-walled hollow circular tube 100 inner wall temperature calibration and measurement device in a high temperature environment, and introduce cooling gas into one of the circular tube installation ends 101;

[0068] Step 2: While maintaining the cooling gas pressure at 0.2 MPa, the high-temperature environment temperature T0 was varied multiple times (to 900°C, 1000°C, and 1100°C), and the corresponding lumen temperature T2 of the thin-walled hollow circular tube 100 (to 863°C, 952°C, and 1037°C) and the lumen temperature T1 of the circular tube mounting end 101 (to 611°C, 688°C, and 755°C) were simultaneously measured.

[0069] Step 3: According to the variation rule of the temperature T0 of the high temperature environment, a corresponding relationship between the lumen temperature T2 of the thin-walled hollow circular tube 100 and the lumen temperature T1 of the circular tube installation end 101 is established.

[0070] According to the changing law of the temperature T0 of the high-temperature environment and the corresponding relationship between the tube cavity temperature T2 of the thin-walled hollow circular tube 100 and the tube cavity temperature T1 of the circular tube mounting end 101, the tube cavity temperature T1 of any circular tube mounting end 101 corresponding to the tube cavity temperature T2 of the thin-walled hollow circular tube 100 can also be obtained by interpolation calculation.

[0071] Using the above calibration method, the test method for measuring the temperature of the inner cavity of a thin-walled hollow circular tube includes the following steps:

[0072] Step 1: Install the test piece in a high-temperature environment of 1000°C. The middle of the test piece is a thin-walled hollow circular tube 113, and the two ends of the test piece are circular tube mounting ends 114. The center of the test piece is a continuous and smooth hollow circular tube cavity 115. At least one circular tube mounting end is provided with a temperature measuring hole 116, and the temperature measuring hole 116 is used to measure the tube cavity temperature T1 of the corresponding circular tube mounting end 114. Cooling gas is introduced into one circular tube mounting end 114. The position of the temperature measuring hole 116 of the circular tube mounting end 114 of the test piece is the same as the position of the temperature measuring hole 103 of the circular tube mounting end 101 of the calibration test piece.

[0073] Step 2: The real-time tube cavity temperature T1 of the round tube installation end 114 is obtained through the temperature measuring hole 116 and is 688° C.

[0074] Step 3. Using the tube cavity temperature T1 of the circular tube mounting end 114 measured in step 2 and the corresponding relationship, the corresponding tube cavity temperature T2 of the thin-walled hollow circular tube 113 is obtained to be 952°C. It can also be obtained by interpolation calculation that under the temperature T0 of a specific high temperature environment (for example, 1050°C), the tube cavity temperature T1 of the circular tube mounting end 101 (approximately 721.5°C) corresponds to the tube cavity temperature T2 of the thin-walled hollow circular tube 100 (approximately 994.5°C).

[0075] The description of various advantageous arrangements has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the examples disclosed. Many modifications and variations will be apparent to those skilled in the art. In addition, different advantageous examples may describe different advantages compared to other advantageous examples. The selected example or examples are chosen and described to best illustrate the principles of the examples, their practical application, and to enable those skilled in the art to understand the disclosure with various examples with various modifications suitable for the particular use contemplated.

Claims

1. A device for calibrating and measuring the inner wall temperature of a thin-walled hollow circular tube, characterized in that: The thickness of the thin-walled hollow circular tube is ≤2mm. A calibration specimen is used in the calibration measurement device. The middle of the calibration specimen is a thin-walled hollow circular tube, and both ends of the calibration specimen are circular tube mounting ends. The center of the calibration specimen is a continuous and smooth hollow circular tube cavity. At least one circular tube mounting end is provided with a temperature measuring hole, and the temperature measuring hole is used to measure the tube cavity temperature of the corresponding circular tube mounting end. The thin-walled hollow circular tube is provided with a stepped through hole, the upper opening of the stepped through hole is gradually expanded, and the upper opening shape is non-circular, and the stepped surface of the stepped through hole is provided with a plurality of pin holes; The step through hole is matched with a cover plate, the cover plate is a boss structure, and the cover plate matches the shape of the step through hole; the outer surface of the cover plate is a cylindrical surface, forming a continuous surface with the outer surface of the thin-walled hollow circular tube, and the inner surface of the cover plate is a cylindrical surface, forming a continuous surface with the inner wall surface of the thin-walled hollow circular tube; the cover plate is provided with a plurality of pin holes, the pin holes of the cover plate correspond to the pin holes of the step through hole one by one, and fixing pins are inserted into the corresponding pin holes of the cover plate and the pin holes of the step through hole; the shape of the outer edge of the cover plate is the same as the shape of the upper opening of the step through hole to ensure position alignment; The cover plate is embedded with a thermocouple, so that the thermocouple can measure the tube cavity temperature of the corresponding thin-walled hollow circular tube.

2. The thin-walled hollow tube inner wall temperature calibration and measurement device according to claim 1, characterized in that: The step through hole is machined by a micro-electro-spark method.

3. The thin-walled hollow circular tube inner wall temperature calibration and measurement device according to claim 1, characterized in that: The pin hole of the cover plate and the pin hole of the step through hole are both provided with key slots, and the fixing pin is provided with a convex key to form a shape fit.

4. The thin-walled hollow circular tube inner wall temperature calibration and measurement device according to claim 1, characterized in that: The pin hole of the step through hole is a blind hole.

5. The thin-walled hollow circular tube inner wall temperature calibration and measurement device according to claim 1, characterized in that: The clearance between the mating surfaces of the step through hole and the cover plate does not exceed 0.1 mm.

6. The thin-walled hollow circular tube inner wall temperature calibration and measurement device according to claim 1, characterized in that: The calibration specimen is a high-temperature alloy.

7. A calibration method for a thin-walled hollow circular tube inner wall temperature calibration measuring device based on any one of claims 1 to 5, characterized in that: The steps include: Step 1, installing the thin-walled hollow circular tube inner wall temperature calibration and measurement device in a high temperature environment, and introducing cooling gas into one installation end of the circular tube; Step 2: Under the temperature TO of the high temperature environment, the flow rate and pressure of the cooling gas are changed for multiple times, and the cavity temperature of the corresponding thin-walled hollow circular tube and the cavity temperature of the circular tube installation end are simultaneously measured; Step 3: According to the changing rules of the flow rate and pressure of the cooling gas, a corresponding relationship between the tube cavity temperature of the thin-walled hollow circular tube and the tube cavity temperature of the circular tube installation end is established.

8. The calibration method of the thin-walled hollow circular tube inner wall temperature calibration measuring device according to claim 7, characterized in that: According to the changing rules of the flow rate and pressure of the cooling gas, and the corresponding relationship between the cavity temperature of the thin-walled hollow circular tube and the cavity temperature of the circular tube installation end, a corresponding relationship curve is established through interpolation calculation.

9. A test method for measuring the inner temperature of a thin-walled hollow circular tube using the calibration method of claim 7 or 8, comprising the following steps: Step 1, install the test piece in a high temperature environment, the middle of the test piece is a thin-walled hollow circular tube, and the two ends of the test piece are circular tube mounting ends; the center of the test piece is a continuous and smooth hollow circular tube cavity; at least one circular tube mounting end is provided with a temperature measuring hole, and the temperature measuring hole is used to measure the tube cavity temperature of the corresponding circular tube mounting end; cooling gas is introduced into one circular tube mounting end; the position of the temperature measuring hole of the circular tube mounting end of the test piece is the same as the position of the temperature measuring hole of the circular tube mounting end of the calibration specimen; Step 2: Obtain the real-time tube cavity temperature of the installation end of the round tube through the temperature measuring hole; Step 3: Using the tube cavity temperature of the installation end of the circular tube measured in step 2 and the corresponding relationship, obtain the tube cavity temperature of the corresponding thin-walled hollow circular tube.

10. A calibration method for a thin-walled hollow circular tube inner wall temperature calibration measuring device based on any one of claims 1 to 5, characterized in that: The steps include: Step 1, installing the thin-walled hollow circular tube inner wall temperature calibration and measurement device in a high temperature environment, and introducing cooling gas into one installation end of the circular tube; Step 2: While the flow rate and pressure of the cooling gas remain unchanged, the temperature TO of the high-temperature environment is changed multiple times, and the lumen temperature of the corresponding thin-walled hollow circular tube and the lumen temperature of the circular tube installation end are synchronously measured; Step 3: According to the variation law of the temperature TO of the high temperature environment, a corresponding relationship between the lumen temperature of the thin-walled hollow circular tube and the lumen temperature of the circular tube installation end is established.

11. The calibration method of the thin-walled hollow circular tube inner wall temperature calibration measuring device according to claim 10, characterized in that: According to the variation law of the temperature TO in the high temperature environment and the corresponding relationship between the lumen temperature of the thin-walled hollow circular tube and the lumen temperature of the circular tube installation end, a corresponding relationship curve is established through interpolation calculation.

12. A test method for measuring the inner temperature of a thin-walled hollow circular tube using the calibration method of claim 10 or 11, comprising the following steps: Step 1, install the test piece in a high temperature environment, the middle of the test piece is a thin-walled hollow circular tube, and the two ends of the test piece are circular tube mounting ends; the center of the test piece is a continuous and smooth hollow circular tube cavity; at least one circular tube mounting end is provided with a temperature measuring hole, and the temperature measuring hole is used to measure the tube cavity temperature of the corresponding circular tube mounting end; cooling gas is introduced into one circular tube mounting end; the position of the temperature measuring hole of the circular tube mounting end of the test piece is the same as the position of the temperature measuring hole of the circular tube mounting end of the calibration specimen; Step 2: Obtain the real-time tube cavity temperature of the installation end of the round tube through the temperature measuring hole; Step 3: Using the tube cavity temperature of the installation end of the circular tube measured in step 2 and the corresponding relationship, obtain the tube cavity temperature of the corresponding thin-walled hollow circular tube.

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