CN114858298B - A dynamic compensation method and system for measuring temperature of a thermocouple high-temperature airflow - Google Patents
A dynamic compensation method and system for measuring temperature of a thermocouple high-temperature airflow Download PDFInfo
- Publication number
- CN114858298B CN114858298B CN202210603636.XA CN202210603636A CN114858298B CN 114858298 B CN114858298 B CN 114858298B CN 202210603636 A CN202210603636 A CN 202210603636A CN 114858298 B CN114858298 B CN 114858298B
- Authority
- CN
- China
- Prior art keywords
- temperature
- thermocouple
- measurement
- heat
- thermocouples
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000000034 method Methods 0.000 title claims abstract description 37
- 238000005259 measurement Methods 0.000 claims abstract description 102
- 230000005855 radiation Effects 0.000 claims abstract description 45
- 238000012546 transfer Methods 0.000 claims abstract description 43
- 238000009529 body temperature measurement Methods 0.000 claims abstract description 18
- 230000000694 effects Effects 0.000 claims abstract description 10
- 230000008569 process Effects 0.000 claims description 10
- 238000003780 insertion Methods 0.000 claims description 7
- 230000037431 insertion Effects 0.000 claims description 7
- PNEYBMLMFCGWSK-UHFFFAOYSA-N Alumina Chemical compound [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 230000000191 radiation effect Effects 0.000 description 2
- 230000003068 static effect Effects 0.000 description 2
- 230000009471 action Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 230000003628 erosive effect Effects 0.000 description 1
- 230000014509 gene expression Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
- G01K7/00—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements
- G01K7/02—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using thermoelectric elements, e.g. thermocouples
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
- G01K1/00—Details of thermometers not specially adapted for particular types of thermometer
- G01K1/20—Compensating for effects of temperature changes other than those to be measured, e.g. changes in ambient temperature
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
- G01K13/00—Thermometers specially adapted for specific purposes
- G01K13/02—Thermometers specially adapted for specific purposes for measuring temperature of moving fluids or granular materials capable of flow
- G01K13/024—Thermometers specially adapted for specific purposes for measuring temperature of moving fluids or granular materials capable of flow of moving gases
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E30/00—Energy generation of nuclear origin
- Y02E30/30—Nuclear fission reactors
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Measuring Temperature Or Quantity Of Heat (AREA)
Abstract
The invention discloses a dynamic compensation method and a system for thermocouple high-temperature airflow temperature measurement, wherein the method comprises the following steps: acquiring a plurality of thermocouple measurement temperatures at the same position in the same environment; for each thermocouple measurement temperature, multiplying the error between the air flow temperature and the thermocouple measurement temperature by a parameter representing the strength of convection heat transfer to be used as the influence of thermal convection on the thermocouple measurement temperature, taking the error between the equivalent temperature of thermal radiation and the thermocouple measurement temperature as the influence of thermal radiation on the thermocouple measurement temperature, and taking the error between the equivalent temperature of the tail part of the thermocouple and the thermocouple measurement temperature as the influence of thermal conduction on the thermocouple measurement temperature; the sum of the effects of heat convection, heat radiation and heat conduction on the thermocouple measurement temperature is equivalent to the derivative of the thermocouple measurement temperature, so that a heat transfer model of each thermocouple is established, and the heat transfer models of a plurality of thermocouples are solved to obtain the air flow temperature. The invention has the advantages of high measuring temperature range, high accuracy of compensation results and high calculation efficiency.
Description
Technical Field
The invention belongs to the field of measurement of high-temperature airflow temperature, and particularly relates to a thermocouple high-temperature airflow temperature measurement dynamic compensation method and system.
Background
The invention is mainly used for accurately measuring the dynamic temperature of high-temperature air flow, and the highest temperature measuring range can reach 1200 ℃. The commonly used sensors for measuring temperature include a thermal expansion type temperature sensor, an infrared temperature sensor, a thermistor, a thermocouple and the like, but are limited by the characteristics of the sensor, and considering from a plurality of angles such as a temperature measuring range, only the thermocouple temperature sensor (called thermocouple for short) is suitable for measuring the temperature of high-temperature airflow. When the thermocouple is used for a long time, the thermocouple is continuously influenced by the effects of erosion, oxidization and the like of high-temperature air flow, and is easy to damage under the high-temperature condition, so that the smaller the diameter is, the lower the upper temperature measurement limit is, and the thermocouple with the high upper temperature measurement limit is generally larger in diameter and is slower in response speed. Therefore, the direct measurement of the temperature of the air flow by using the thermocouple has larger dynamic errors, wherein the dynamic errors are divided into thermal convection errors of the thermocouple and the air flow to be measured, thermal radiation errors between the thermocouple and the surrounding environment and thermal conduction errors between the thermocouple head and the tail. In addition, static heat radiation errors and static heat conduction errors still exist when the thermocouple head temperature is kept unchanged under the influence of environmental heat radiation and heat conduction action between the thermocouple heads and the thermocouple tails. The errors are measurement errors which are necessarily influenced by the heat transfer law in the nature, and only the difference in size is achieved.
The existing compensation method can compensate the dynamic thermal convection error, but no method capable of simultaneously and dynamically compensating all the errors exists at present. Based on this, it is necessary to propose a method capable of compensating for the thermal convection, thermal radiation and thermal conduction errors simultaneously with respect to the effects of the thermal convection, thermal radiation and thermal conduction.
Therefore, the prior art has the technical problems that the influence of heat convection, heat radiation and heat conduction on the measurement result is not considered at the same time, so that the measurement temperature range is narrow, and the accuracy of the compensation result is low.
Disclosure of Invention
Aiming at the defects or improvement demands of the prior art, the invention provides a thermocouple high-temperature airflow temperature measurement dynamic compensation method and a thermocouple high-temperature airflow temperature measurement dynamic compensation system, which solve the technical problems that the influence of heat convection, heat radiation and heat conduction on a measurement result is not considered at the same time in the prior art, so that the measurement temperature range is narrow and the compensation result accuracy is low.
In order to achieve the above object, according to one aspect of the present invention, there is provided a thermocouple high temperature air flow temperature measurement dynamic compensation method, comprising:
acquiring a plurality of thermocouple measurement temperatures at the same position in the same environment;
For each thermocouple measurement temperature, multiplying the error between the air flow temperature and the thermocouple measurement temperature by a parameter representing the strength of convection heat transfer to be used as the influence of thermal convection on the thermocouple measurement temperature, taking the error between the equivalent temperature of thermal radiation and the thermocouple measurement temperature as the influence of thermal radiation on the thermocouple measurement temperature, and taking the error between the equivalent temperature of the tail part of the thermocouple and the thermocouple measurement temperature as the influence of thermal conduction on the thermocouple measurement temperature;
The sum of the effects of heat convection, heat radiation and heat conduction on the thermocouple measurement temperature is equivalent to the derivative of the thermocouple measurement temperature, so that a heat transfer model of each thermocouple is established, and the heat transfer models of a plurality of thermocouples are solved to obtain the air flow temperature.
Further, the sum of the thermocouple measurement temperature and the air temperature corresponds to the sum of the thermocouple tail equivalent temperature and the derivative of the thermocouple tail equivalent temperature, thereby calculating the thermocouple tail equivalent temperature.
Further, the equivalent temperature of the thermocouple tail is calculated by the following formula:
Wherein T is the thermocouple measurement temperature, ta is the air temperature, L t is the thermocouple tail length, T t is the thermocouple tail equivalent temperature, G t is the derivative of the thermocouple tail equivalent temperature, L l is the distance between the thermocouple heads and tails, phi a is the coefficient (calculated according to an empirical formula or the number of Knoop and known parameters) for characterizing the natural convection heat transfer strength, lambda s is the thermocouple heat conductivity, R s is the radius of the thermocouple, rho s is the thermocouple density, and c s is the thermocouple specific heat capacity.
Further, the heat transfer model is:
wherein phi is a parameter representing the strength of convection heat transfer, T g is the air flow temperature, sigma is the Boltzmann constant, epsilon is the emissivity of the thermocouple surface, T w is the equivalent temperature of heat radiation, G is the derivative of the measured temperature of the thermocouple, and L s is the thermocouple head length.
Further, the derivative of the thermocouple measured temperature is calculated by:
and setting the width of a window, intercepting the data of the width of the window from the thermocouple measurement temperature in the dynamic process, and carrying out weighted average on a plurality of intercepted data to obtain the derivative of the thermocouple measurement temperature.
Further, the plurality of thermocouple measurement temperatures are obtained when the plurality of thermocouples are subjected to the same heat radiation, the plurality of thermocouples are identical in length, and the plurality of thermocouples are identical in axial insertion depth.
Further, the plurality of thermocouple measurement temperatures are obtained by simultaneously measuring a plurality of thermocouples with different diameters.
Further, the plurality of thermocouple measurement temperatures is at least three thermocouple measurement temperatures.
According to another aspect of the present invention, there is provided a thermocouple high temperature airflow temperature measurement dynamic compensation system comprising:
The acquisition module is used for acquiring a plurality of thermocouple measurement temperatures at the same position in the same environment;
The compensation module is used for measuring the temperature of each thermocouple, multiplying the error between the air flow temperature and the thermocouple measurement temperature by the parameter representing the strength of convection heat transfer to be used as the influence of heat convection on the thermocouple measurement temperature, taking the error between the equivalent heat of heat radiation and the thermocouple measurement temperature as the influence of heat radiation on the thermocouple measurement temperature, and taking the error between the equivalent temperature of the tail part of the thermocouple and the thermocouple measurement temperature as the influence of heat conduction on the thermocouple measurement temperature; the sum of the effects of heat convection, heat radiation and heat conduction on the thermocouple measurement temperature corresponds to the derivative of the thermocouple measurement temperature, thereby establishing a heat transfer model for each thermocouple; and solving a heat transfer model of the thermocouples to obtain the air flow temperature.
Further, the acquisition module comprises at least three thermocouples which are positioned at the same position in the same environment, wherein the same position in the same environment indicates that the plurality of thermocouples are same in heat radiation, the plurality of thermocouples are the same in length, and the plurality of thermocouples are consistent in axial insertion depth.
In general, the above technical solutions conceived by the present invention, compared with the prior art, enable the following beneficial effects to be obtained:
(1) The invention acquires a plurality of thermocouple measurement temperatures at the same position in the same environment, so as to ensure that the plurality of thermocouples measure the same air flow temperature, namely the plurality of thermocouple measurement temperatures correspond to the same real air flow temperature. For each thermocouple to measure the temperature, the influence of heat convection, heat radiation and heat conduction on the measurement result is considered, a heat transfer model is built, the air flow temperature is solved, the heat convection, heat radiation and heat conduction errors existing in the measurement process of the high-temperature air flow temperature can be dynamically compensated, the accuracy of the measurement result of the high-temperature air flow temperature is improved, and the method has a good compensation effect in the measurement of the air flow temperature at 300 ℃ and above.
(2) According to the invention, the tail temperature of the thermocouple is only related to the air temperature and the measured temperature of the thermocouple, the tail temperature of the thermocouple depends on the heat conduction between the head and the tail of the thermocouple and the heat convection effect between the tail of the thermocouple and the air, and the equivalent temperature of the tail of the thermocouple is calculated through the head temperature of the thermocouple and the air temperature by utilizing the relation, so that the number of unknown parameters is reduced, and an equation which cannot be solved originally can be solved.
(3) The traditional heat transfer model only considers the influence of heat convection on the measured temperature, and the heat transfer model of the invention simultaneously considers the influence of heat convection, heat radiation and heat conduction on the measured result, so that the heat transfer process of the thermocouple under the influence of heat convection, heat radiation and heat conduction can be accurately described. The unknown parameters in the heat transfer model include parameters representing the strength of convection heat transfer, equivalent heat radiation temperature and airflow temperature, so when three or more thermocouples are used for measuring the temperature, three unknown quantities can be obtained after the heat transfer models of the three thermocouples are combined.
(4) The invention solves the derivative of the measured temperature by using a moving average method, and the solving result has smaller hysteresis and lower noise. The thermocouples have the same heat radiation, the same length of the thermocouples and the same radial insertion depth of the thermocouples, so that the actual air flow temperature corresponding to the measured temperature of different thermocouples is always ensured, and the thermocouple is also a means for controlling unknown parameters. The diameters of thermocouples are different so that a plurality of transfer models are different, and if the diameters are the same, the measured temperatures are the same, and the transfer models cannot be solved.
Drawings
FIG. 1 is a schematic diagram of a thermocouple heat transfer process provided by an embodiment of the present invention;
FIG. 2 is a block diagram of a thermocouple high temperature airflow temperature measurement device provided by an embodiment of the present invention;
FIG. 3 is a flow chart of a dynamic compensation method for thermocouple high temperature air flow temperature measurement provided by an embodiment of the invention;
FIG. 4 (a) is a graph comparing the measured value T 1 with the actual value provided by the embodiment of the present invention;
FIG. 4 (b) is a graph comparing the measured value T 2 with the actual value provided by the embodiment of the present invention;
FIG. 4 (c) is a graph comparing the measured value T 3 with the actual value provided by the embodiment of the present invention;
FIG. 4 (d) is a graph comparing the compensated air flow temperature with the actual value provided by the embodiment of the present invention.
Detailed Description
The present invention will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present invention more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention. In addition, the technical features of the embodiments of the present invention described below may be combined with each other as long as they do not collide with each other.
The terms "inserted", "same environment", "depth", "airflow passage", "mounted" and similar expressions used herein are for illustrative purposes only and do not represent the only embodiment, without intermediate elements.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and/or" as used herein includes any and all combinations of one or more of the associated listed items.
Furthermore, the terms "thermocouple 1", "thermocouple 2", "thermocouple 3" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "thermocouple 1", "thermocouple 2", "thermocouple 3" may include one or more of such features, either explicitly or implicitly. In the description of the present invention, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.
The heat transfer process of the thermocouple is shown in fig. 1, the thermocouple head is subjected to the heat radiation effect of the high-temperature plasma spray gun arc and the alumina ceramic wall surface, the thermocouple head and the tail have the heat conduction effect, in addition, the thermocouple head and the airflow conduct heat through heat convection, and the three heat transfer modes all have influence on the measurement result of the thermocouple, so that a large measurement error exists. Therefore, it is necessary to compensate for the measurement results of the thermocouple in the embodiment.
As shown in fig. 2, the thermocouple high temperature air flow temperature measuring device includes: the thermocouples 1,2, 3 and the reference thermocouples are uniformly arranged around the alumina ceramic pipeline and inserted into the pipeline to the same depth. The two ends of the joint are respectively provided with an inlet and an outlet for high-temperature airflow; when in use, the air flow passage is directly connected into the high-temperature air flow pipeline, so that the air flow temperature can be measured. Since the smaller the diameter of the thermocouple, the smaller the measurement error thereof, the diameter of the reference thermocouple used for comparison with the compensated thermocouple measurement result in the example was 0.127mm. The measurement result of the reference thermocouple was taken as the gas flow temperature Tg. The reference thermocouple is arranged at the head of the other thermocouple with the diameter of 1mm, and is used for ensuring that the environments of all thermocouples are consistent. According to the method, according to the temperature measurement results of the three thermocouples, the heat transfer characteristics of the thermocouples are combined, the thermal convection, thermal radiation and thermal conduction errors existing in the high-temperature airflow temperature measurement are overcome, and the dynamic temperature of the high-temperature airflow is accurately measured.
In use, the number of thermocouples is at least three.
As shown in fig. 3, a dynamic compensation method for measuring the temperature of a thermocouple high-temperature airflow comprises the following steps:
acquiring a plurality of thermocouple measurement temperatures at the same position in the same environment;
For each thermocouple measurement temperature, multiplying the error between the air flow temperature and the thermocouple measurement temperature by a parameter representing the strength of convection heat transfer to be used as the influence of thermal convection on the thermocouple measurement temperature, taking the error between the equivalent temperature of thermal radiation and the thermocouple measurement temperature as the influence of thermal radiation on the thermocouple measurement temperature, and taking the error between the equivalent temperature of the tail part of the thermocouple and the thermocouple measurement temperature as the influence of thermal conduction on the thermocouple measurement temperature;
The sum of the effects of heat convection, heat radiation and heat conduction on the thermocouple measurement temperature is equivalent to the derivative of the thermocouple measurement temperature, so that a heat transfer model of each thermocouple is established, and the heat transfer models of a plurality of thermocouples are solved to obtain the air flow temperature.
The derivative of the thermocouple measured temperature is calculated as follows:
and setting the width of a window, intercepting the data of the width of the window from the thermocouple measurement temperature in the dynamic process, and carrying out weighted average on a plurality of intercepted data to obtain the derivative of the thermocouple measurement temperature.
Wherein G is the derivative of the measured temperature, m is the window width, m is more than or equal to 2, namely the number of intercepted data, and T i is the ith measured temperature data in the window.
When three thermocouples are used for measuring temperature, three thermocouples with different diameters are used for measuring simultaneously, the depths of the thermocouples inserted into the airflow channels are the same, and the measuring positions are consistent. Three thermocouples with different diameters are adopted for simultaneous measurement, the depths of the thermocouples inserted into the airflow passages are the same, and the measurement positions are consistent. The three thermocouples are arranged on the air flow passage through the thermocouple clamping sleeve, the insertion depths are identical, the insertion depths of the thermocouples in the radial direction of the air flow passage are identical, the measurement positions are identical, the axial directions of the thermocouples are in the same plane in the axial direction of the air flow passage, and the distance between the end parts of the thermocouples is smaller than the maximum diameter of the three thermocouples. The thermocouple end refers to the head of the thermocouple measurement site, and the thermocouple is not fully inserted inside the airflow path.
The dynamic compensation method regards the heat radiation effect suffered by the three thermocouple heads inserted into the airflow passage as the same, and expresses the same parameter, and considers that the temperature of the tail part of the thermocouple not inserted into the airflow passage is only related to the measured temperature of the thermocouple. The heat transfer process of the thermocouple head is described by adopting three heat transfer modes of heat convection, heat radiation and heat conduction, and is expressed as follows.
Wherein R s1、Rs2、Rs3 is the radius of three thermocouples, T 1、T2、T3 is the measured temperature of the three thermocouples, epsilon is the emissivity of the thermocouple surface, sigma is the Boltzmann constant, T w is the parameter representing the intensity of heat radiation-the equivalent temperature of heat radiation, T t1、Tt2、Tt3 is the parameter representing the temperature of the tail of the thermocouple-the equivalent temperature of the tail of the thermocouple, and G 1、G2、G3 is the derivative of the measured temperature T 1、T2、T3.
The method comprises the following steps:
Step S100: and (3) data acquisition: reading the current measured temperatures T 1、T2、T3 of the three thermocouples;
step S200: updating the data buffer: three independent buffer areas are adopted to temporarily store the measured temperature of the thermocouple, if the number of data in the buffer areas is smaller than the window size m, the current measured temperature is written into the buffer areas, otherwise, one data of the buffer areas is written first, and then the current measured temperature is written into the buffer areas;
Step S300: the moving average method calculates the derivative: calculating the derivative G 1、G2、G3 of the current measured temperature according to the data of the buffer area by using a moving average method;
Step S400: calculating the equivalent temperature of the tail part of the thermocouple: calculating three thermocouple tail equivalent temperatures T t1、Tt2、Tt3 according to the current measured temperature and the air temperature;
Step S500: the dynamic compensation method calculates the actual air flow temperature: the actual airflow temperature T g is solved for according to T 1、T2、T3、G1、G2、G3、Tt1、Tt2、Tt3.
According to the invention, the air flow temperature of the same position is measured by the three thermocouples under the same condition, and the model of the thermocouple heat transfer process containing the heat radiation and heat conduction influence is obtained according to the characteristics of the thermocouples, so that the heat transfer process of the thermocouples under the heat radiation and heat conduction influence can be accurately described; solving the derivative of the measured temperature by using a moving average method, wherein the solving result has smaller hysteresis and lower noise; the relation between the equivalent temperature of the thermocouple temperature and the equivalent temperature of the thermocouple head is put forward, and the equivalent temperature of the thermocouple tail is calculated through the thermocouple head temperature and the air temperature by utilizing the relation, so that the number of unknown parameters is reduced, and an equation which cannot be solved originally can be solved; the air flow temperature is obtained by solving an equation set consisting of heat transfer models of three thermocouples, so that heat radiation and heat conduction errors existing in high-temperature air flow temperature measurement are reduced, and accuracy of high-temperature air flow temperature measurement results is improved.
As shown in fig. 4 (a), 4 (b) and 4 (c), before compensation, the measured temperatures T 1、T2、T3 of the three thermocouples are all significantly different from the actual air flow temperature T g (thermocouples with a diameter of 0.127mm smaller, which have an error of about 1/8 of T 1). As shown in fig. 4 (d), the measured temperature after compensation is closer to the airflow temperature T g than before compensation.
When the thermocouple measurement result is compensated, the influence of heat radiation and heat conduction is effectively taken into consideration, and measurement errors caused by heat convection, heat radiation and heat conduction can be compensated simultaneously. The method can be applied to accurate measurement of high-temperature airflow temperature, and has the characteristics of high measurement temperature range, high accuracy of compensation results, high calculation efficiency and the like.
It will be readily appreciated by those skilled in the art that the foregoing description is merely a preferred embodiment of the invention and is not intended to limit the invention, but any modifications, equivalents, improvements or alternatives falling within the spirit and principles of the invention are intended to be included within the scope of the invention.
Claims (6)
1. A dynamic compensation method for measuring the temperature of a thermocouple high-temperature airflow is characterized by comprising the following steps:
acquiring a plurality of thermocouple measurement temperatures at the same position in the same environment;
For each thermocouple measurement temperature, multiplying the error between the air flow temperature and the thermocouple measurement temperature by a parameter representing the strength of convection heat transfer to be used as the influence of thermal convection on the thermocouple measurement temperature, taking the error between the equivalent temperature of thermal radiation and the thermocouple measurement temperature as the influence of thermal radiation on the thermocouple measurement temperature, and taking the error between the equivalent temperature of the tail part of the thermocouple and the thermocouple measurement temperature as the influence of thermal conduction on the thermocouple measurement temperature;
The sum of the influences of heat convection, heat radiation and heat conduction on the thermocouple measurement temperature is equivalent to the derivative of the thermocouple measurement temperature, so that a heat transfer model of each thermocouple is established, and the heat transfer models of a plurality of thermocouples are solved to obtain the air flow temperature;
The sum of the thermocouple measurement temperature and the air temperature is equal to the sum of the thermocouple tail equivalent temperature and the derivative of the thermocouple tail equivalent temperature, so that the thermocouple tail equivalent temperature is calculated;
The equivalent temperature of the thermocouple tail is calculated by the following formula:
Wherein T is the thermocouple measurement temperature, ta is the air temperature, L t is the thermocouple tail length, T t is the thermocouple tail equivalent temperature, G t is the derivative of the thermocouple tail equivalent temperature, L l is the distance between the thermocouple heads and the thermocouple tails, phi a is the coefficient representing the natural convection heat transfer intensity, lambda s is the thermocouple heat conduction coefficient, R s is the radius of the thermocouple, rho s is the thermocouple density, and c s is the thermocouple specific heat capacity; the heat transfer model is as follows:
Wherein phi is a parameter representing the strength of convection heat transfer, T g is the air flow temperature, sigma is the Boltzmann constant, epsilon is the emissivity of the thermocouple surface, T w is the equivalent temperature of heat radiation, G is the derivative of the measured temperature of the thermocouple, and L s is the length of the thermocouple head;
the derivative of the thermocouple measured temperature is calculated as follows:
and setting the width of a window, intercepting the data of the width of the window from the thermocouple measurement temperature in the dynamic process, and carrying out weighted average on a plurality of intercepted data to obtain the derivative of the thermocouple measurement temperature.
2. The dynamic compensation method for measuring high-temperature air flow temperature of a thermocouple according to claim 1, wherein the measured temperatures of the thermocouples are obtained under the conditions that the thermocouples are subjected to the same heat radiation, the thermocouples are identical in length and the axial insertion depths of the thermocouples are identical.
3. The dynamic compensation method for measuring the high-temperature air flow temperature of the thermocouple according to claim 1, wherein the plurality of thermocouple measurement temperatures are obtained by simultaneously measuring a plurality of thermocouples with different diameters.
4. A thermocouple high temperature airflow temperature measurement dynamic compensation method as claimed in any one of claims 1-3 wherein said plurality of thermocouple measurement temperatures is at least three thermocouple measurement temperatures.
5. A thermocouple high temperature airflow temperature measurement dynamic compensation system for performing the thermocouple high temperature airflow temperature measurement dynamic compensation method of claim 1, comprising:
The acquisition module is used for acquiring a plurality of thermocouple measurement temperatures at the same position in the same environment;
The compensation module is used for measuring the temperature of each thermocouple, multiplying the error between the air flow temperature and the thermocouple measurement temperature by the parameter representing the strength of convection heat transfer to be used as the influence of heat convection on the thermocouple measurement temperature, taking the error between the equivalent heat of heat radiation and the thermocouple measurement temperature as the influence of heat radiation on the thermocouple measurement temperature, and taking the error between the equivalent temperature of the tail part of the thermocouple and the thermocouple measurement temperature as the influence of heat conduction on the thermocouple measurement temperature; the sum of the effects of heat convection, heat radiation and heat conduction on the thermocouple measurement temperature corresponds to the derivative of the thermocouple measurement temperature, thereby establishing a heat transfer model for each thermocouple; and solving a heat transfer model of the thermocouples to obtain the air flow temperature.
6. The dynamic compensation system for measuring the high-temperature air flow temperature of the thermocouples, as set forth in claim 5, wherein the acquisition module comprises at least three thermocouples at the same position in the same environment, the same position in the same environment indicates that the plurality of thermocouples are subjected to the same heat radiation, the plurality of thermocouples are identical in length, and the plurality of thermocouples are identical in axial insertion depth.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210603636.XA CN114858298B (en) | 2022-05-27 | 2022-05-27 | A dynamic compensation method and system for measuring temperature of a thermocouple high-temperature airflow |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210603636.XA CN114858298B (en) | 2022-05-27 | 2022-05-27 | A dynamic compensation method and system for measuring temperature of a thermocouple high-temperature airflow |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114858298A CN114858298A (en) | 2022-08-05 |
| CN114858298B true CN114858298B (en) | 2024-11-19 |
Family
ID=82641691
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210603636.XA Active CN114858298B (en) | 2022-05-27 | 2022-05-27 | A dynamic compensation method and system for measuring temperature of a thermocouple high-temperature airflow |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114858298B (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1076781A (en) * | 1992-03-24 | 1993-09-29 | 西安交通大学 | Compensation high temperature gas flow thermometry and measuring instrument |
| CN106124078A (en) * | 2016-07-25 | 2016-11-16 | 北京航空航天大学 | A kind of method using double-thermocouple to measure strong transient fluid temperature |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102012003407B4 (en) * | 2012-02-23 | 2013-10-24 | Phoenix Contact Gmbh & Co. Kg | Temperature measuring module with position compensation |
| TWI489092B (en) * | 2014-05-06 | 2015-06-21 | Wistron Corp | Temperature detecting device and temperature detecting panel thereof |
| KR101704222B1 (en) * | 2015-06-24 | 2017-02-08 | 엘에스산전 주식회사 | Method for temperature drift compensation of temperature measurement device using thermocouple |
| CN208721269U (en) * | 2018-09-10 | 2019-04-09 | 中国科学院工程热物理研究所 | A temperature measuring device |
| CN114235193B (en) * | 2021-11-26 | 2025-05-23 | 中国航空工业集团公司北京长城计量测试技术研究所 | Quick response temperature sensor based on multiple frequency compensation |
-
2022
- 2022-05-27 CN CN202210603636.XA patent/CN114858298B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1076781A (en) * | 1992-03-24 | 1993-09-29 | 西安交通大学 | Compensation high temperature gas flow thermometry and measuring instrument |
| CN106124078A (en) * | 2016-07-25 | 2016-11-16 | 北京航空航天大学 | A kind of method using double-thermocouple to measure strong transient fluid temperature |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114858298A (en) | 2022-08-05 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US6691019B2 (en) | Method and system for controlling distortion of turbine case due to thermal variations | |
| CN109100051B (en) | Temperature correction method and device for dynamic response of temperature sensor | |
| Papaioannou et al. | Effect of thermocouple size on the measurement of exhaust gas temperature in internal combustion engines | |
| CN113375620B (en) | Coil pipe ice thickness detection method based on temperature measurement, sensor and system | |
| CN106441472A (en) | Method for temperature drift inhibition of constant power type thermal type gas flowmeter | |
| CN109885885B (en) | A Nozzle Stem Wall Temperature Prediction Method Based on Gas-Solid-Liquid Three-Phase Coupling Heat Transfer | |
| CN114858298B (en) | A dynamic compensation method and system for measuring temperature of a thermocouple high-temperature airflow | |
| Ji et al. | Error of thermocouple in measuring surface temperature of blade with cooling film | |
| CN119374760B (en) | Temperature sensor group calibrating device for temperature rise environment | |
| CN101147050B (en) | Metal surface temperature measuring device | |
| Van Dijk et al. | The calibration of (multi-) hot-wire probes. 1. Temperature calibration | |
| Joachimiak et al. | Stable solution to nonstationary inverse heat conduction equation | |
| WO2021219024A1 (en) | Apparatus and method for measuring temperature of object in space | |
| JPH09329503A (en) | Temperature measuring device for heat transfer compensation | |
| CN116754101A (en) | A temperature measurement correction method for high-temperature solid walls | |
| CN117610197A (en) | Turbine blade temperature field prediction method based on physical information neural network | |
| CN113984220B (en) | Differential blackbody radiation temperature difference correction method based on equivalent emissivity | |
| CN114235193B (en) | Quick response temperature sensor based on multiple frequency compensation | |
| CN113639896A (en) | An indirect temperature measurement method of aero-engine casing | |
| CN115930873A (en) | Estimation device, estimation method, and computer-readable recording medium | |
| CN208653673U (en) | Short thermocouple temperature calibration furnace | |
| CN113960108A (en) | Method and system for simultaneously measuring heat conductivity coefficient and specific heat capacity of carbon fiber composite material | |
| CN112560316A (en) | Correction method for surface temperature field of space target | |
| CN111649848A (en) | Temperature recovery coefficient determination method | |
| CN115435913B (en) | Hanging type double stagnation cover total temperature probe head based on platinum resistor |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |