Pipeline temperature measurement temperature correction method

Abstract

The application discloses a pipeline temperature measurement temperature correction method, comprising the following steps: performing calibration experiments, obtaining first temperature measurement array data and second temperature measurement array data on the outer and inner surfaces of the pipeline respectively; constructing a thermal physical model of the pipeline to be measured, calculating a first temperature derivative, and obtaining an energy balance equation of the relationship between the inner and outer surfaces of the pipeline; substituting the first temperature measurement array data and the second temperature measurement array data into the energy balance equation to obtain a complete energy balance equation; performing verification experiments, obtaining third temperature measurement array data and fourth temperature array data on the outer and inner surfaces of the pipeline respectively; substituting the third temperature measurement array data into the complete energy balance equation, reconstructing the pipeline inner surface temperature array data and calculating a second temperature derivative; and comparing the reconstructed temperature array data with the fourth temperature array data to calculate errors. The application adopts a reverse heat conduction temperature correction method to correct the pipeline temperature measurement, so that the accuracy and stability of the measurement results are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of temperature measurement, and particularly relates to a pipeline temperature measurement temperature correction method. BACKGROUND

[0002] At present, temperature measurement usually adopts two methods. One is non-contact temperature measurement, and common methods include optical thermometers, radiation thermometers and infrared thermometers, etc., which can measure the temperature without contacting the measured object. The other is contact temperature measurement, which needs to directly contact the sensitive element of the temperature sensor with the measured object, and uses the heat conduction method to reach the heat balance state, so as to measure the actual temperature of the measured object.

[0003] In order to ensure the normal operation of the underground pipeline and prevent various faults caused by the excessively high temperature inside and outside the pipeline, it is very important to measure the actual temperature of the pipeline.

[0004] When measuring the temperature of the inner surface of the pipeline, the above-mentioned non-contact temperature measurement does not need to tightly contact the sensor with the surface of the measured pipeline, but is greatly affected by the emissivity of the object, the measurement distance, smoke and water vapor and other external factors, and has a large measurement error, so it is not suitable for pipeline detection. The temperature transmission scheme in the contact temperature measurement is easily disturbed by the environmental temperature due to the very complex environment inside and outside the pipeline, and it is difficult to obtain the real temperature change of the pipeline. At the same time, the internal environment of the pipeline is very harsh, and the temperature measurement device is easily corroded and oxidized and causes aging failure in the long-term harsh environment, so it is difficult to directly arrange the sensor inside, and the practicability and effectiveness are greatly affected. SUMMARY

[0005] The purpose of the present application is to provide a pipeline temperature measurement temperature correction method, which uses temperature correction technology when measuring the inner wall of the pipeline to eliminate the influence of the external environment on the temperature, so as to improve the accuracy and stability of the temperature measurement result of the inner surface of the pipeline.

[0006] The technical scheme of the present application is as follows:

[0007] A pipeline temperature measurement temperature correction method comprises the following steps:

[0008] obtaining a first temperature measurement array data {T o1} of the temperature measurement points on the outer surface of the pipeline changing with time step, and obtaining a second temperature measurement array data {T i1} of the temperature measurement points on the inner surface of the pipeline changing with time step;

[0009] constructing a thermal physical model of the pipeline to be measured, calculating the first derivative of the temperature measurement array data changing with time step, and obtaining an energy balance equation of the relationship between the inner and outer surfaces of the pipeline as shown in formula (1),

[0010]

[0011] wherein, is the difference of the measured temperature array data of the inner and outer surface of the pipeline, is the derivative of the measured temperature array data of the outer surface of the pipeline with respect to time, and α, β and γ are unknown coefficients in the equation;

[0012] substitute the first temperature array data {T o1} and the second temperature array data {T i1} into the above energy balance equation to obtain the unknown coefficients in the equation and obtain the complete energy balance equation;

[0013] obtain the third temperature array data {T o2} of the temperature measuring points on the outer surface of the pipeline with respect to time step, and obtain the fourth temperature array data {T i2} of the temperature measuring points on the inner surface of the pipeline with respect to time step;

[0014] substitute the third temperature array data {T o2} into the above obtained complete energy balance equation to calculate the second derivative of the temperature array data of the temperature measuring points on the outer surface of the pipeline with respect to time step, and reconstruct the temperature array data {T 重构} of the temperature measuring points on the inner surface of the pipeline with respect to time step;

[0015] compare the reconstructed temperature array data {T 重构} of the temperature measuring points on the inner surface of the pipeline with respect to time step with the obtained fourth temperature array data {T i2} to calculate the error.

[0016] Preferably, the calculation of the temperature derivative comprises the following steps:

[0017] estimate the true value of the time step Q by using a polynomial fitting containing a 2De+1 data moving window, wherein De is the data in the polynomial, and then filter the noise data, so that there is a polynomial f(t) of Ee order:

[0018]

[0019] obtain the coefficient a i by least square method, and then filter the temperature derivative of the time step, so that there is:

[0020]

[0021] In the formula, T TC is the temperature measured by the thermocouple.

[0022] Preferably, the method for obtaining the unknown coefficient α comprises the following steps:

[0023] The heat flow rate from the temperature measuring point to the hot junction of the thermocouple is counted, so as to obtain the response signal of the thermocouple, and based on the response signal of the thermocouple, the pipe temperature measured by the thermocouple is obtained;

[0024] Based on the pipe temperature information measured by the thermocouple, the heat capacity information of the thermocouple is obtained, and the characteristic value of the response time is obtained by using the least square method, and the characteristic value is α.

[0025] Preferably, in the pipe measurement, the characteristic value α of the response time is calculated by the following formula:

[0026]

[0027] In the formula, T0 is the measured value of the thermocouple at t=0, T S is the real-time measured value of the thermocouple, and T p is the temperature at the specific point P of the measurement.

[0028] Preferably, the method for obtaining the unknown coefficients β and γ comprises the following steps:

[0029] The temperature change information of each temperature measuring point is counted, and these parameters are estimated through a calibration process to obtain the prior two thermocouple responses;

[0030] Based on the prior two thermocouple responses, and using two different heat input sequences to perform the calibration step to estimate the β and γ parameters.

[0031] Preferably, the temperature array data {T 重构} of the pipe inner surface temperature measuring point changing with time step is reconstructed, comprising the following steps:

[0032] The first temperature measuring array data {T o1} and the second temperature measuring array data {T i1} are substituted into the energy balance equation, so that:

[0033]

[0034] The temperature array data under the time sample number Q is substituted into the above formula, and formula (2) is obtained:

[0035] Z=D1C (2)

[0036] Wherein,

[0037] Z is an unknown coefficient matrix,

[0038] C is the temperature experimental data difference between the pipe outer surface and the pipe inner surface measured by the thermocouple,

[0039] D1 is a first inverse matrix,

[0040] The third temperature measurement array data {T o2} is substituted into formula (3) to reconstruct the temperature array data {T 重构} of the inner surface temperature measurement point of the pipeline changing with time step:

[0041]

[0042] Wherein:

[0043] Z is an unknown coefficient matrix, Z=D1C

[0044] D2 is a second inverse matrix,

[0045] Preferably, the pipeline temperature measurement temperature correction method is realized by the following pipeline temperature measurement device, the pipeline temperature measurement device comprises a cover body, a thermocouple temperature probe and a shielding shell; the cover body comprises a ring-shaped check ring and a sealing part connected to one end of the ring-shaped check ring, an arc-shaped mounting surface matched with the shape of the outer wall of the pipeline to be detected is arranged on the other end face of the ring-shaped check ring, and the cover body is used for being fixed on the outer surface of the pipeline to be detected in a sealed and close manner; the thermocouple temperature probe is arranged in the cover body and fixed at the center of the sealing part, the measuring end part of the thermocouple temperature probe is in contact with the outer surface of the pipeline to be detected, and is used for collecting the surface temperature of the pipeline; the shielding shell is arranged on the cover body and connected to the back side of the sealing part of the cover body through a fixed support, the shielding shell is internally provided with a temperature correction processing module, the temperature correction processing module is electrically connected with the thermocouple temperature probe, and is used for correcting the temperature data collected by the thermocouple temperature probe.

[0046] Preferably, a sealing sleeve is arranged in the cover body, the sealing sleeve is arranged on the outside of the thermocouple temperature probe and fixed with the sealing part of the cover body, and is used for protecting the thermocouple temperature probe.

[0047] Preferably, the cover body is made of anticorrosive and insulating material.

[0048] Compared with the prior art, the present application has the following advantages:

[0049] 1. In the present application, when the inner and outer walls of the pipeline are measured, the temperature correction method based on inverse heat conduction is used, the thermocouple signal with fast response time installed on the outer surface of the pipeline is used to correct the thermocouple signal with slow response time on the inner surface of the pipeline, so as to correct the pipeline temperature measurement, reduce the influence of the external environment on the temperature, and improve the accuracy and stability of the measurement result.

[0050] 2、The present application only needs to measure the temperature of the outer surface of the pipeline through the temperature measuring device outside the pipeline to obtain the temperature of the inner surface of the pipeline, without installing the temperature measuring device inside the pipeline, thereby avoiding the problem of failure caused by environmental factors when installing the temperature measuring device inside the pipeline.

[0051] 3、The arc-shaped mounting surface arranged at the cover opening is attached to the surface of the pipeline to be detected, and the sealing ring is arranged to avoid direct contact between the pipeline surface temperature probe and the surrounding environment, thereby reducing the influence of the external environment on the temperature measurement result. BRIEF DESCRIPTION OF DRAWINGS

[0052] Figure 1 The schematic diagram of the pipeline temperature measurement temperature correction method of the present application is shown in the figure.

[0053] Figure 2 The schematic diagram of the pipeline temperature measuring device of the present application is shown in the figure.

[0054] Figure 3 The first perspective view of the shielding shell in the pipeline temperature measuring device of the present application is shown in the figure.

[0055] Figure 4 The second perspective view of the shielding shell in the pipeline temperature measuring device of the present application is shown in the figure.

[0056] Figure 5 The schematic diagram of the fixing bracket structure in the pipeline temperature measuring device of the present application is shown in the figure.

[0057] Figure 6 The schematic diagram of the cover structure in the pipeline temperature measuring device of the present application is shown in the figure.

[0058] Figure 7 The schematic diagram of the assembly structure of the cover and the thermocouple temperature probe in the pipeline temperature measuring device of the present application is shown in the figure.

[0059] Figure 8 The schematic diagram of the processing module structure in the pipeline temperature measuring device of the present application is shown in the figure.

[0060] Figure 9 The result and error analysis diagram of the measurement and reconstruction of the present application in the calibration experiment is shown in the figure.

[0061] Figure 10 The result and error analysis diagram of the measurement and reconstruction of the first group of verification experiments of the present application is shown in the figure.

[0062] Figure 11 The result and error analysis diagram of the measurement and reconstruction of the second group of verification experiments of the present application is shown in the figure.

[0063] Figure 12This is a schematic diagram showing the results and error analysis of the third set of verification experiments in this application embodiment. Detailed Implementation

[0064] The following is in conjunction with the appendix Figures 1 to 12 The specific embodiments of the present invention will be described in detail below. In the description of the invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature; in the description of the invention, unless otherwise stated, "a plurality of" means two or more.

[0065] Example 1

[0066] like Figure 1 As shown, this embodiment of the invention provides a method for correcting the temperature of a pipeline, including the following steps:

[0067] A calibration experiment was conducted to acquire the first temperature array data {T} of the temperature measurement points on the outer surface of the pipe as a function of time steps. o1}, acquire second temperature array data {T} of temperature measurement points changing with time step on the inner surface of the pipe. i1}

[0068] Specifically, In the formula, Q represents the number of temperature array data samples that change over time, and T represents the transpose operation.

[0069] A thermophysical model of the pipe to be tested is constructed, and the first derivative of the temperature array data of the outer surface of the pipe with time is calculated. Since the thermocouple has a thermal hysteresis effect on temperature change, based on the analysis of the physical model, an energy balance equation is extracted at the same measurement point of the thermocouple, thereby establishing the heat balance equation of the thermocouple measurement point and obtaining the energy balance equation of the relationship between the inner and outer surfaces of the pipe as shown in equation (1).

[0070]

[0071] in, The difference between the measured array data of the inner and outer surfaces of the pipe. Let α be the derivative of the temperature array data on the outer surface of the pipe as a function of time step, where α, β, and γ are unknown coefficients in the equation.

[0072] Further, in calculating the first derivative of the pipe surface temperature array data with respect to time, if the pipe temperature array data obtained from the calibration experiment is smooth and noiseless, such as in the pipe surface numerical simulation, a simple finite difference method is sufficient to calculate the temperature derivative, but in the actual pipe surface temperature measurement, there is always an embedded noise, so it is necessary to reduce the noise effect of temperature derivative calculation when calculating the temperature derivative. Specifically, the calculation of the temperature derivative includes the following steps:

[0073] To reduce the noise effect of temperature derivative calculation, the noise data is filtered by using a polynomial fitting containing a 2De+1 data moving window to estimate the true value of the time step Q, where De is the data in the polynomial, and then there is a polynomial f(t) of Ee order:

[0074]

[0075] Obtain its coefficient a i which can be obtained by least squares, by filtering the temperature derivative at time step Q, that is:

[0076]

[0077] Where, for the polynomial, selecting a very small order may lead to poor fitting of the rapid transient curve, and setting a very high order, but still limited to Ee≤2De, can provide an over-fitting function that fluctuates with noise;

[0078] In order to obtain a more stable solution, the temperature derivative of the estimation equation at time step Q is calculated using several fitted polynomial orders, for example, for De=15, the order is from 3 to 6, and the average derivative of them is calculated, that is:

[0079]

[0080] In the formula, T TC is the temperature measured by the thermocouple.

[0081] Further, the method for obtaining the unknown coefficient α in the calibration experiment includes the following steps:

[0082] Statistically obtain the heat flow rate from the temperature measurement point to the hot junction of the thermocouple, so as to obtain the response signal of the thermocouple, and based on the response signal of the thermocouple, obtain the pipe temperature measured by the thermocouple;

[0083] Based on the pipe temperature information measured by the thermocouple, obtain the heat capacity information of the thermocouple, and use the least squares method to obtain the characteristic value of the response time, which is α;

[0084] Wherein, in the pipe application example, the characteristic value α of the response time is calculated by the following formula:

[0085]

[0086] where T0 is the thermocouple measurement at t = 0, T S is the real-time measurement of the thermocouple, T p is the temperature at a specific point P measured.

[0087] where, when the response time is considered as the product of the equivalent thermal resistance and the thermal capacity, it is easier to understand the estimation of the measured thermocouple response time.

[0088] Further, the method of obtaining the unknown coefficients β and γ in the calibration experiment includes the following steps:

[0089] Statistically, the temperature change information of each temperature measuring point is obtained, and these parameters are estimated through a calibration calibration process to obtain the prior two thermocouple responses;

[0090] Based on the prior two thermocouple responses, and using two different heat input sequences to perform the calibration step to estimate the β and γ parameters.

[0091] Further, in order to facilitate calculation, α, β and γ are collectively referred to as unknown coefficient matrix Z, and the calculation of the unknown coefficient matrix Z includes the following steps:

[0092] Substitute the calibration experiment data T o1 and T i1 into the energy balance equation, then:

[0093]

[0094] Specifically, the following matrix equation is obtained by measuring the temperature array data under the number of time samples Q:

[0095]

[0096] Let C be the temperature experimental data difference between the outer surface of the pipeline and the inner surface of the pipeline measured by the thermocouple, and

[0097] Let

[0098] Let Z be the unknown coefficient matrix,

[0099]

[0100] Therefore, the unknown coefficient matrix Z can also be represented by formula (2)

[0101] Z = D1C (2)

[0102] A verification experiment is performed, and a third temperature measuring array data {To2},in the pipe inner surface to obtain the fourth temperature array data {T i2} with time step changes, wherein,

[0103] The third temperature measurement array data {T o2} is substituted into the complete energy balance equation, the measured filter and Gaussian filter are added to filter the pipe outer surface thermocouple response signal data, and the inverse heat conduction program calculation link is started to calculate the second derivative of the pipe outer surface temperature measurement array data with time step changes, and it should be noted that the method for calculating the second derivative of the pipe outer surface temperature measurement array data with time step changes is the same as the above-mentioned method for calculating the first derivative, and the temperature array data {T 重构} of the temperature measurement point of the pipe inner surface with time step changes is reconstructed.

[0104] Specifically, the temperature array data of the pipe inner surface is reconstructed according to formula (3):

[0105]

[0106] In the formula:

[0107] Z is an unknown coefficient matrix, Z=D1C

[0108]

[0109] The temperature array data {T 重构} of the temperature measurement point of the pipe inner surface with time step changes is reconstructed and compared with the fourth temperature array data {T i2} obtained to realize the comparison between the data obtained by the sensor with the algorithm and the measured data, so as to reflect the accuracy of the correction method, and further reflect the advantages of indirect temperature measurement.

[0110] Wherein, the above process is briefly described, the response signal of the thermocouple measured outside the pipe is identified as a fast response time signal, the response signal of the thermocouple inside the pipe is identified as a slow response time signal, the relative response time is obtained according to the parameter information of the two kinds of response signals, and the thermocouple slow response time signal is reconstructed by the thermocouple fast response time signal measurement result.

[0111] As Figure 9 shown, the result and error analysis diagram of the measurement and reconstruction in the calibration experiment of the present application,

[0112] Wherein, Figure 9 Left graph: the dotted line is the measured temperature of the pipe outer surface, the dashed line is the measured temperature of the pipe inner surface, and the solid line is the reconstructed temperature of the pipe inner surface by the temperature correction algorithm

[0113] Figure 9 Right figure: the solid line represents the difference between the reconstructed temperature and the measured temperature of the inner surface of the pipeline, which fluctuates around 0, indicating that the reconstructed temperature is highly accurate; the dashed line represents the difference between the measured temperature of the outer surface of the pipeline and the measured temperature of the inner surface of the pipeline, which highlights the accuracy of the solid line group.

[0114] As shown in Figures 10-11 , three sets of verification experimental data are respectively represented, i.e. three different temperature fluctuation information in the pipeline, the reconstructed graph based thereon and the error.

[0115] Example 2

[0116] As shown in Figures 2-8 , this embodiment discloses a pipeline temperature measuring device based on example 1, which comprises a cover body 31, a thermocouple temperature probe 4, a sealing ring 5 and a shielding shell 11; the cover body 31 is made of anticorrosive and insulating material, and comprises an annular stop ring and a sealing part connected to one end of the annular stop ring; an arc-shaped mounting surface matching the shape of the outer wall of the pipeline to be detected is arranged on the other end face of the annular stop ring; the cover body 31 is used for airtight and fixedly attached to the outer surface of the pipeline to be detected; the thermocouple temperature probe 4 is arranged in the cover body 31 and fixed at the center of the sealing part; the measuring end of the thermocouple temperature probe 4 is in contact with the outer surface of the pipeline to be detected for collecting the surface temperature of the pipeline; the sealing ring 5 is fixed inside the cover body 31 and sleeved outside the thermocouple temperature probe 4 for protecting the thermocouple temperature probe 4; the shielding shell 11 is arranged on the cover body 31 and connected with the cover body 31 through a fixed support 21; the shielding shell 11 is internally provided with a temperature correction processing module; the temperature correction processing module is electrically connected with the thermocouple temperature probe 4 for correcting the temperature array data collected by the thermocouple temperature probe 4.

[0117] The fixed support 21 is arranged between the cover body 31 and the shielding shell 11 for connecting the cover body 31 with the shielding shell 11; when connected, the cover body 31 is nested and installed at the lower end of the fixed support 21; the shielding shell 11 is provided with a plurality of first threaded holes 7; the fixed support 21 is provided with a plurality of second threaded holes 9; after the first threaded holes 7 and the second threaded holes 9 are aligned, the two are fixedly connected by bolts; and the thermocouple temperature probe 4 and the sealing ring 5 are installed inside the cover body 31. Figure 3 As shown in Figure 5 the shielding shell 11 is provided with a threading hole 6 at the bottom end for arranging the thermocouple collection line to the pipeline surface temperature probe.The fixed support 21 shown has a threading hole 8 for laying the line of the pipeline surface thermocouple temperature sensor; after assembly, the entire cover body 31 and the fixed support 21 are fixed to the pipeline to be measured by a binding belt, the arc-shaped mounting surface of the cover body 31 is attached to the pipeline surface, so that the thermocouple temperature probe 4 contacts the outer surface of the pipeline, and the arc-shaped mounting surface design of the cover body 31 and the design of the sealing ring 5 greatly reduce the interference of the environment temperature on the measured pipeline temperature.

[0118] Specifically, the processing module includes a thermocouple acquisition module, a protection filter module, a LoRa wireless transmission module and a microprocessor I installed in the shielding shell 11, the thermocouple acquisition module is used to convert the temperature array data collected by the thermocouple temperature probe 4 into an electrical signal and perform amplification and filtering and other processing; the processing module further includes an upper computer control box, the upper computer control box is built-in LoRa wireless receiving module, protection filter module, liquid crystal display module and microprocessor II installed with temperature correction processing system.

[0119] The microprocessor I is used to control the work of the thermocouple acquisition module, digitize the collected temperature array data, and send the processed data to the LoRa wireless transmission module; the LoRa wireless transmission module is used to send the processed data to the LoRa wireless receiving module through the LoRa wireless communication protocol; the LoRa wireless receiving module is used to receive the data sent by the LoRa wireless transmission module and decode it; the liquid crystal display module is used to display the collected temperature array data and the corrected temperature array data; the microprocessor II is used to execute the temperature correction program algorithm based on inverse heat conduction.

[0120] The sealing ring 5 is made of silicone rubber; the fixed support 21 is made of stainless steel or titanium alloy material; the shielding shell 11 is made of stainless steel or titanium alloy material; the cover body 31 is made of corrosion-resistant non-metal material, specifically made of polypropylene elastic material.

[0121] After the components in the shielding shell are installed, they are installed on the middle fixed structure by screws through the fixed groove, the temperature signal measured by the shielding shell is wirelessly transmitted to the LoRa wireless receiving module in the upper computer control black box through the LoRa wireless transmission module in the lower computer shielding shell, and the pipeline inner surface temperature measured by the pipeline inner surface temperature probe is corrected by the pipeline outer surface temperature detected by the thermocouple temperature probe 4 installed in the cover body, so that the design method greatly reduces the influence of the environment temperature on the measured pipeline surface temperature, takes into account the influence of the environment temperature on the actual operating temperature of the pipeline inner and outer surfaces, and avoids the trouble of electromagnetic interference of the wired signal transmission line.

[0122] In summary, the use principle of the temperature measuring device is as follows: during measurement, the cover body 31 is nested and installed at the lower end of the fixed support 21, the shielding shell 11 is fixedly installed at the upper end of the fixed support 21, the thermocouple temperature probe 4 and the sealing ring 5 are installed in the cover body 31, the whole cover body 31 and the fixed support 21 are fixed to the pipeline to be measured through the binding belt, the arc-shaped mounting surface of the cover body 31 is attached to the outer surface of the pipeline, meanwhile, the thermocouple temperature probe 4 contacts the surface of the pipeline to measure the surface temperature of the pipeline, the design of the arc-shaped mounting surface of the cover body 31 and the design of the sealing ring 5 avoid the direct contact between the pipeline surface temperature probe and the surrounding environment, the shielding shell 11 is designed as a hollow structure, and the circuit board and circuit wires for temperature signal processing are installed in the shielding shell 11, the demodulated temperature signal is sent through the LoRa wireless transmission module and transmitted to the LoRa wireless receiving module in the host computer device, the obtained reconstructed temperature signal and the original measured signal are displayed on the liquid crystal display module at the same time through the temperature correction algorithm module based on heat conduction. The temperature signal with fast response time installed on the outer surface of the pipeline is used to correct the temperature signal with slow response time on the inner surface of the pipeline, so that the influence of the external environment on the temperature is further eliminated, and the temperature of the inner surface of the pipeline is more accurately measured.

[0123] The above disclosure is only the preferred several specific embodiments of the present application, but the embodiments of the present application are not limited thereto, and any changes that can be thought of by those skilled in the art shall fall within the protection scope of the present application.

Claims

1. A temperature correction method for pipe thermometry, characterized by, The method comprises the following steps: Obtaining first temperature measurement array data of temperature measurement points on the outer surface of the pipeline changing with time step T o1 Obtaining second temperature measurement array data of temperature measurement points on the inner surface of the pipeline changing with time step T i1} constructing a thermophysical model of the pipeline to be measured, calculating the first derivative of the time-varying temperature array data of the outer surface of the pipeline, and obtaining an energy balance equation of the relationship between the inner and outer surfaces of the pipeline as shown in equation (1); （1） wherein, is the difference between the temperature array data measured on the inner and outer surfaces of the pipe, is the derivative of the temperature array data measured on the outer surface of the pipe with respect to the time step, , and are unknown coefficients in the equation. Substitute the first temperature measuring array data { T o1} and the second temperature measuring array data { T i1} into the above energy balance equation, solve the unknown coefficients in the equation, and obtain the complete energy balance equation; Obtaining third temperature array data of the temperature measuring points on the outer surface of the pipeline changing with time step T o2 Obtaining fourth temperature array data of the temperature measuring points on the inner surface of the pipeline changing with time step T i2} The data from the third temperature measurement array { T o2 Substituting these values ​​into the complete energy balance equation obtained above, the second derivative of the temperature array data on the outer surface of the pipe as a function of time step is calculated, and the temperature array data of the temperature measurement points on the inner surface of the pipe as a function of time step is reconstructed. T 重构 }; The temperature array data of the temperature measuring point on the inner surface of the pipeline changing with time steps will be reconstructed T 重构 Error comparison calculation is performed between the reconstructed temperature array data and the acquired fourth temperature array data T i2 ​ The first derivative of the time-varying temperature array data of the outer surface of the pipeline comprises the following steps: By using a polynomial fit comprising 2De+1 data moving windows to estimate the true value of the time step Q and filter noisy data, where Deis the data in the polynomial, then there is Ee a polynomial f( t ) of degree De+1: The coefficients thereof are obtained by least square method By filtering the temperature derivative over the time step, one has: In the formula, T TC temperature measured by a thermocouple; obtaining the unknown coefficients comprises the steps of: The heat flow rate from the temperature measurement point to the hot junction of the thermocouple is calculated to obtain the response signal of the thermocouple, and the pipeline temperature measured by the thermocouple is obtained based on the response signal of the thermocouple; Based on the thermocouple measurement of the pipeline temperature information, the heat capacity information of the thermocouple is obtained, the least square method is used to obtain the characteristic value of the response time, and the characteristic value is ; In pipe measurement, the eigenvalue of the response time is calculated using the following formula : wherein T 0 is the thermocouple measurement at t = 0, T S is the thermocouple real-time measurement, T p is the temperature at the specific point P of measurement; obtaining the unknown coefficients and The method comprises the steps of: The temperature change information of each temperature measurement point is calculated, and the two prior thermocouple responses are obtained by a calibration process to estimate these parameters; The calibration step is performed based on the a priori knowledge of the response of the two thermocouples and using two different heat input sequences to estimate and parameters.

2. The temperature correction method of a pipe temperature measurement according to claim 1, characterized by, reconstructing temperature array data of the inner surface of the pipeline at time steps T 重构} comprising the steps of: Substituting the first temperature array data { T o1} and the second temperature array data { T i1} into the energy balance equation, we have: Substitute the temperature array data with the number of time samples Q into the above equation to obtain equation (2): （2） Wherein, Z for an unknown coefficient matrix, ; C the difference between the temperature array data measured by the thermocouples for the outside surface of the pipe and the inside surface of the pipe, ; D 1 is a first inverse matrix, ; The third temperature measuring array data T o2 is substituted into formula (3) to reconstruct the temperature array data of the measuring point on the inner surface of the pipeline with time step change T 重构 : （3） Wherein: Z is an unknown coefficient matrix, D 2 for the second inverse matrix, .

3. The temperature correction method of a pipe temperature measurement according to any one of claims 1 to 2, characterized by, Based on the pipeline temperature measuring device, the pipeline temperature measuring device comprises: The cover body (31) comprises an annular retainer and a sealing part connected to one end of the annular retainer, the other end face of the annular retainer is provided with an arc-shaped mounting surface matched with the shape of the outer wall of the pipeline to be detected, and the cover body (31) is used for sealing and fixedly connected to the outer surface of the pipeline to be detected; The thermocouple temperature probe (4) is arranged in the cover body (31) and fixed at the center of the sealing part, the measuring end of the thermocouple temperature probe (4) is in contact with the outer surface of the pipeline to be detected, and the thermocouple temperature probe (4) is used for collecting the surface temperature of the pipeline; The shielding shell (11) is arranged on the cover body (31) and connected to the back side of the sealing part of the cover body (31) through the fixing support (21), the shielding shell (11) is internally provided with a temperature correction processing module, the temperature correction processing module is electrically connected with the thermocouple temperature probe (4), and the temperature correction processing module is used for correcting the temperature array data collected by the thermocouple temperature probe (4).

4. The temperature correction method of a pipe temperature measurement according to claim 3, characterized by, The cover body (31) is internally provided with a sealing sleeve (5), the sealing sleeve (5) is sleeved on the outside of the thermocouple temperature probe (4) and fixed with the sealing part of the cover body (31), and is used for protecting the thermocouple temperature probe (4).

5. The temperature correction method of a pipe temperature measurement according to claim 4, wherein The cover body (31) is made of anticorrosive and insulating material.

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