A total temperature probe structure with self-compensation of heat conduction error
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-07-01
- Publication Date
- 2026-08-11
AI Technical Summary
[0005]本发明实施例提供一种导热误差自补偿型的总温探针结构，以解决现有总温探针通过改变支杆结构降低导热误差时导致结构强度削弱且误差降幅有限的技术问题
[0022]本发明中，在不改变探针原有结构参数和机械强度的前提下，通过外置加热机构对探针支杆肋根处进行加热，有效降低探针支杆表面的温度梯度，从而大幅减小偶丝结点与基准点之间的温差；同时，根据总温探针测试系统实时测得的测温数据，动态调整电加热机构的加热温度，形成闭环反馈控制，实现了对屏蔽式总温探针的导热误差自补偿功能：
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Figure CN122544967A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of aero-engine testing technology, and in particular to a total temperature probe structure with self-compensating thermal conductivity error. Background Technology
[0002] High-precision temperature measurement is a core element of aero-engine core performance evaluation and condition monitoring. Its measurement accuracy directly determines the accuracy of turbine inlet temperature field reconstruction and the ability to resolve the thermal gradient at the combustion chamber exit, providing crucial support for engine thermodynamic cycle parameter optimization and fault early warning. However, with the iterative upgrades of aero-engine technology, the internal operating temperature of the turbine continues to rise, posing greater challenges to high-precision temperature measurement. Currently, although various temperature measurement methods exist, the total temperature probe still occupies an important position in the field of engine temperature measurement due to its mature research system, systematic structural improvement schemes, and comprehensive error assessment methods.
[0003] The steady-state error of shielded total temperature probes mainly stems from two mechanisms: velocity error and heat transfer error (including thermal conduction and radiation errors). Thanks to mature shielding design technology, the coefficient of restitution of current total temperature probes can generally reach above 0.95, and velocity error has been effectively controlled. However, in practical applications, heat transfer error typically accounts for more than 90% of the total error, becoming the main factor affecting temperature measurement accuracy.
[0004] To address the aforementioned issues, existing solutions primarily reduce thermal conductivity errors by altering the probe support structure. For example, slots are created at the probe bottom to enhance convective heat transfer, or holes are drilled in the probe support to further enhance convective heat transfer, thereby reducing thermal conductivity errors. However, these methods have significant limitations: firstly, they significantly reduce structural strength; secondly, the reduction in thermal conductivity errors is limited. Therefore, there is an urgent need to develop a total temperature probe structure that reduces thermal conductivity errors while maintaining the original structural parameters and mechanical strength of the probe. Summary of the Invention
[0005] This invention provides a total temperature probe structure with self-compensating thermal conductivity error to solve the technical problem that existing total temperature probes reduce thermal conductivity error by changing the support structure, resulting in weakened structural strength and limited error reduction.
[0006] In view of the above technical problems, embodiments of the present invention provide a total temperature probe structure with self-compensating thermal conductivity error, comprising:
[0007] Shielded total temperature probe body, heating mechanism and temperature feedback control system;
[0008] The shielded total temperature probe body includes a probe support rod and a coupler wire node disposed at the front end of the probe support rod.
[0009] The heating mechanism is located at the rib root of the probe support rod and is used to heat the rib root of the probe support rod to reduce the temperature gradient on the surface of the probe support rod.
[0010] The temperature feedback control system is electrically connected to the heating mechanism and is used to perform closed-loop adjustment of the heating temperature of the heating mechanism based on the total temperature data measured in real time by the temperature testing system until the temperature change of the filament junction is less than a preset threshold, so as to achieve self-compensation of thermal conductivity error.
[0011] Optionally, the heating mechanism is located outside the mounting base of the probe support or outside the casing, and the heating of the probe support by the heating mechanism does not change the internal structural parameters and mechanical strength of the shielded total temperature probe body.
[0012] Optionally, the heating mechanism includes any one of an electric heating element, an electromagnetic heating element, an infrared heating element, or a hot fluid circulation heating element.
[0013] Optionally, the temperature feedback control system includes:
[0014] The temperature acquisition module is used to acquire the total temperature data measured in real time by the temperature testing system;
[0015] The control calculation module is used to calculate the adjustment temperature of the heating mechanism based on the deviation between the total temperature data and the target total temperature.
[0016] The drive output module is used to output the adjusted temperature to the heating mechanism and control the heating power of the heating mechanism.
[0017] Optionally, the correction time interval of the temperature feedback control system is 2τ to 3τ, where τ is the total time constant, τ = τ1 + τ2;
[0018] τ1 is the time constant of heat transfer to the temperature measurement position where the filament junction is located after the heating mechanism heats the probe support rod;
[0019] τ2 is the time constant for the filament node to reach thermal equilibrium again after sensing the heating of the rib root.
[0020] Optionally, the preset threshold is a preset value ε. When the temperature change of the filament node is less than the preset value ε after two or more consecutive adjustments, the self-compensation is determined to be complete.
[0021] Optionally, after the self-compensation, the thermal conductivity error of the shielded total temperature probe body is reduced to a maximum of 1% before compensation, and the corrected thermal conductivity error does not exceed 0.56K.
[0022] In this invention, without altering the original structural parameters and mechanical strength of the probe, an external heating mechanism heats the root of the probe support rod, effectively reducing the temperature gradient on the surface of the probe support rod, thereby significantly reducing the temperature difference between the filament junction and the reference point. Simultaneously, based on the real-time temperature data measured by the total temperature probe testing system, the heating temperature of the electric heating mechanism is dynamically adjusted, forming a closed-loop feedback control, thus achieving self-compensation for the thermal conductivity error of the shielded total temperature probe.
[0023] In terms of structural integrity, since the heating mechanism is located on the outside of the probe support rib root, no changes need to be made to the internal structure of the probe. The original structural parameters and mechanical strength of the probe are fully maintained, avoiding the strength weakening problem caused by structural modifications such as support grooving in the prior art. This ensures the structural reliability and service life of the probe under harsh conditions such as high temperature, high pressure and high vibration of aero-engines.
[0024] Regarding the error reduction effect, by heating the rib root of the probe support rod, the temperature gradient on the surface of the support rod almost disappears, the temperature of the probe support rod rises significantly, and the thermal conductivity error can be reduced to 1% of the value before compensation, and the corrected thermal conductivity error does not exceed 0.56K; at the same time, the reduction in thermal conductivity error leads to a synchronous reduction in radiation error, and all components of steady-state error are optimized. The total error can be reduced to 1 / 4 of the value before the support rod is heated, and at least 3 / 5 of the value before the support rod is heated, resulting in a significant improvement in overall temperature measurement accuracy.
[0025] In terms of versatility and adaptability, the heating method used in this invention is not limited to electric heating; electromagnetic heating, infrared heating, and hot fluid circulation heating are all applicable, and this method can be used for probes of any configuration. Through real-time temperature feedback and closed-loop adjustment of heating temperature, the heating parameters can be automatically adjusted according to the real-time temperature of the test system until the temperature change at the junction of the dipole wires is less than a preset threshold, so that the probe can maintain a high-precision temperature measurement state throughout the entire operating range, providing more reliable temperature data support for the performance evaluation and condition monitoring of aero-engine cores. Attached Figure Description
[0026] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0027] Figure 1 This is a total temperature probe structure with self-compensating thermal conductivity error in one embodiment of the present invention;
[0028] Figure 2This is a cross-sectional view of a total temperature probe structure with self-compensating thermal conductivity error in one embodiment of the present invention;
[0029] Figure 3 This is a comparison diagram of the steady-state error of the shielded total temperature probe body in one embodiment of the present invention;
[0030] Figure 4 This is a surface temperature cloud map of the shielded total temperature probe body;
[0031] Figure 5 This is a flowchart of a self-compensation method for thermal conductivity error in one embodiment;
[0032] Figure 6 This is a diagram showing the change in thermal conductivity error of the probe support rod before and after heating in one embodiment;
[0033] Figure 7 This is a diagram showing the variation of the components of the steady-state error of the probe support rod before and after heating in one embodiment;
[0034] Figure 8 This is an example of the change law of the total steady-state error of the probe support before and after heating.
[0035] The reference numerals in the accompanying drawings are as follows:
[0036] 1-Shielded total temperature probe body, 101-Probe support rod, 102-Dual wire node, 103-Rib root, 2-Heating mechanism. Detailed Implementation
[0037] To make the technical problems solved, the technical solutions, and the beneficial effects of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
[0038] In the description of this invention, it should be understood that the terms "longitudinal," "radial," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.
[0039] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.
[0040] like Figure 1 and Figure 2 As shown, an embodiment of the present invention provides a total temperature probe structure with self-compensating thermal conductivity error, comprising:
[0041] The shielded total temperature probe body 1, the heating mechanism 2, and the temperature feedback control system;
[0042] The shielded total temperature probe body 1 includes a probe support rod 101 and a filament junction 102 disposed at the front end of the probe support rod 101.
[0043] The heating mechanism 2 is disposed at the rib root 103 of the probe support rod 101 and is used to heat the rib root 103 of the probe support rod 101 to reduce the temperature gradient on the surface of the probe support rod 101.
[0044] The temperature feedback control system is electrically connected to the heating mechanism 2 and is used to perform closed-loop adjustment of the heating temperature of the heating mechanism 2 based on the total temperature data measured in real time by the temperature testing system until the temperature change of the filament junction 102 is less than a preset threshold, so as to achieve self-compensation of thermal conductivity error.
[0045] In one embodiment, such as Figure 1 As shown, the heating mechanism 2 is located outside the mounting base of the probe support rod 101 or outside the casing. The heating mechanism 2 does not change the internal structural parameters and mechanical strength of the shielded total temperature probe body 1 when heating the probe support rod 101.
[0046] In one embodiment, the heating mechanism 2 includes any one of an electric heating element, an electromagnetic heating element, an infrared heating element, or a hot fluid circulation heating element.
[0047] In one embodiment, the temperature feedback control system includes:
[0048] The temperature acquisition module is used to acquire the total temperature data measured in real time by the temperature testing system;
[0049] The control calculation module is used to calculate the adjustment temperature of the heating mechanism 2 based on the deviation between the total temperature data and the target total temperature.
[0050] The drive output module is used to output the adjusted temperature to the heating mechanism 2 and control the heating power of the heating mechanism 2.
[0051] Understandably, the design concept of the self-compensating total temperature probe structure for thermal conductivity error stems from, for example... Figure 3 As shown, the velocity error of the shielded total temperature probe body 1 accounts for a very small proportion, but the thermal conductivity and radiation errors account for a large proportion, especially in low Mach number environments, where the thermal conductivity error can account for more than 90% of the total error. Therefore, a method to reduce the magnitude of the probe's thermal conductivity error is urgently needed. The thermal conductivity error prediction model is expressed by the following mathematical expression. As shown, it can be found that two factors affect the thermal conductivity error of the shielded total temperature probe body 1: one is the temperature at the reference point (i.e., at the root of the thermocouple wire); the other is the convective heat transfer coefficient of the thermocouple wire.
[0052]
[0053] in, Indicates thermal conductivity error. Indicates the temperature of the even wire rib root. This indicates the static temperature of the fluid around the junction of the even wires. Indicates the length of the even wire. This represents the heat transfer characteristics of the even wire, where is the convective heat transfer coefficient of the dipole wire. The heat transfer perimeter of the thermocouple wire, Let be the thermal conductivity of the even wire. The heat exchange area of the thermocouple wire.
[0054] Simultaneously observe the temperature cloud map on the probe surface, such as Figure 4 As shown, a significant temperature difference exists between the thermocouple junction 102 and the reference point of the total temperature probe, which is the main reason for the large thermal conductivity error of the probe. This temperature difference is caused by the low temperature of the rib root 103 of the probe support 101. The figure shows a large temperature gradient on the probe support 101. Reducing this temperature gradient would decrease the thermal conductivity error. After heating the probe support 101, the temperature gradient almost disappears, and the temperature of the probe support 101 rises significantly, thus reducing the thermal conductivity error.
[0055] In one embodiment, the correction time interval of the temperature feedback control system is 2τ to 3τ, where τ is the total time constant and τ = τ1 + τ2.
[0056] τ1 is the time constant of the heat transfer from the heating mechanism 2 to the temperature measurement position of the filament junction 102 after the probe support rod 101 is heated.
[0057] τ2 is the time constant for the even wire node 102 to reach thermal equilibrium again after sensing the heating of the rib root 103.
[0058] Understandably, the heating temperature of the electric heating mechanism 2 can be adjusted in real time using the total temperature measured by the temperature testing system, as specifically implemented as follows: Figure 5 As shown. Since the thermal conductivity error is caused by a temperature gradient on the probe support 101, it's crucial to determine the appropriate heating temperature to eliminate this gradient. Ideally, heating to the total incoming flow temperature would eliminate the gradient, but this is difficult to predict in practice. Therefore, a self-compensation method is proposed, which corrects the temperature in real-time based on the measured temperature from the testing system. First, a temperature measurement is performed using the probe. Due to the temperature gradient on the probe support 101, the error is significant. The measured total temperature is denoted as T. 测n Then, turn on heating mechanism 2 to raise the heating temperature to T. 测n After heating, the temperature gradient on the surface of the probe support 101 will decrease, and the error will be reduced. At this time, the testing system will feed back a new total temperature T. 测n+1 This is the result of one round of iteration. A certain time constant is defined for the waiting time here, requiring the system to stabilize. Finally, it is determined whether the change in probe error during this iteration is less than a preset value. If it is less, self-compensation is complete; if it is greater, a new round of iteration is performed until the error change is less than the preset value.
[0059] In one embodiment, the preset threshold is a preset value ε. When the temperature change of the filament node 102 is less than the preset value ε after two or more consecutive adjustments, it is determined that the self-compensation is completed.
[0060] In one embodiment, after the self-compensation, the thermal conductivity error of the shielded total temperature probe body 1 is reduced to 1% of the value before compensation, and the corrected thermal conductivity error does not exceed 0.56K.
[0061] The present invention also provides a method for self-compensation of thermal conductivity error of the above-mentioned total temperature probe structure, comprising the following steps:
[0062] S1. Start the heating mechanism 2 to heat the rib root 103 of the probe support rod 101.
[0063] Step S1 further includes the following sub-steps:
[0064] S101. Determine the source of thermal conductivity error of the shielded total temperature probe body 1. The thermal conductivity error originates from the temperature difference between the filament junction 102 and the reference point at the rib root 103 of the probe support rod 101. The temperature difference is caused by the low temperature of the rib root 103 of the probe support rod 101 and the large temperature gradient on the surface of the probe support rod 101.
[0065] S102. The heating mechanism 2 is configured outside the rib root 103 of the probe support rod 101. The configuration of the heating mechanism 2 does not change the internal structure of the shielded total temperature probe.
[0066] S2. After waiting for 2τ to 3τ, the real-time total temperature data of the dipole wire node 102 is obtained through the temperature testing system.
[0067] S3. Calculate and adjust the set temperature of the heating mechanism 2 based on the deviation between the real-time total temperature data and the target total temperature.
[0068] In step S3, the method for adjusting the set temperature of the heating mechanism 2 includes:
[0069] When the real-time total temperature is lower than the target total temperature, the set temperature of the heating mechanism 2 is increased.
[0070] When the real-time total temperature is higher than the target total temperature, the set temperature of the heating mechanism 2 is reduced.
[0071] When the deviation between the real-time total temperature and the target total temperature is within the allowable range, the current set temperature of the heating mechanism 2 is maintained.
[0072] S4. Repeat steps S2 to S3 until the temperature change at the junction of the dipole wires 102 is less than the preset threshold ε, thus completing the self-compensation of the thermal conductivity error. In step S4, after self-compensation, the total steady-state error of the shielded total temperature probe body 1 is reduced to a maximum of 1 / 4 before compensation and a minimum of 3 / 5 before compensation.
[0073] Understandably, the self-compensation method for thermal conductivity error in this total temperature probe structure does not require changing the specific configuration of the probe; it can significantly reduce thermal conductivity error simply by heating the probe mounting base externally. The heating method is not limited to electric heating; it is merely an example here. This method can be used to reduce thermal conductivity error for probes of any configuration. The beneficial effects of this structure are as follows: Figure 6 As shown, the reduction in thermal conductivity error is significant. Regardless of the level of thermal conductivity error, after the probe support 101 is heated by the self-calibration system, its thermal conductivity error can be reduced to a maximum of 1% of the original value, and the corrected thermal conductivity error does not exceed 0.56K, thus achieving an effective self-calibration function for probe thermal conductivity error.
[0074] Understandably, after heating the probe support 101, the variation patterns of each component of the steady-state error are as follows: Figure 7 As shown, both thermal conductivity error and radiation error are reduced to a certain extent. Furthermore, the variation law of the total error is as follows: Figure 8 As shown, the total error can be reduced to a maximum of 1 / 4 of the value before heating the support rod 101, and a minimum of 3 / 5 of the value before heating the support rod, with a significant reduction in the total error.
[0075] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.
Claims
1. A total temperature probe structure of a self-compensating type for thermal conduction error, characterized by, include: The shielded total temperature probe body (1), the heating mechanism (2), and the temperature feedback control system; The shielded total temperature probe body (1) includes a probe support rod (101) and a filament junction (102) disposed at the front end of the probe support rod (101). The heating mechanism is located at the rib root (103) of the probe support rod (101) and is used to heat the rib root (103) of the probe support rod (101) to reduce the temperature gradient on the surface of the probe support rod (101). The temperature feedback control system is electrically connected to the heating mechanism (2) and is used to perform closed-loop adjustment of the heating temperature of the heating mechanism (2) based on the total temperature data measured in real time by the temperature testing system until the temperature change of the filament junction (102) is less than a preset threshold, so as to achieve self-compensation of thermal conductivity error.
2. The total temperature probe structure of claim 1, wherein, The heating mechanism (2) is located outside the mounting base of the probe support rod (101) or outside the casing. The heating mechanism (2) does not change the internal structural parameters and mechanical strength of the shielded total temperature probe body (1) when heating the probe support rod (101).
3. The total temperature probe structure of claim 2, wherein The heating mechanism includes any one of an electric heating element, an electromagnetic heating element, an infrared heating element, or a hot fluid circulation heating element.
4. The total temperature probe structure of claim 3, wherein The temperature feedback control system includes: The temperature acquisition module is used to acquire the total temperature data measured in real time by the temperature testing system; The control calculation module is used to calculate the adjustment temperature of the heating mechanism based on the deviation between the total temperature data and the target total temperature. The drive output module is used to output the adjusted temperature to the heating mechanism and control the heating power of the heating mechanism.
5. The total temperature probe structure of claim 4, wherein The correction time interval of the temperature feedback control system is 2τ~3τ, where τ is the total time constant, τ=τ1+τ2; τ1 is the time constant of the heat transfer from the heating mechanism (2) to the temperature measurement position of the filament junction (102) after the probe support rod (101) is heated; τ2 is the time constant for the even wire node (102) to reach thermal equilibrium again after feeling the heating of the rib root (103).
6. The total temperature probe structure of claim 5, wherein The preset threshold is a preset value ε. When the temperature change of the ferrule node (102) is less than the preset value ε after two or more consecutive adjustments, the self-compensation is determined to be completed.
7. The total temperature probe structure of claim 6, wherein After the self-compensation, the thermal conductivity error of the shielded total temperature probe body (1) is reduced to 1% of the value before compensation, and the corrected thermal conductivity error does not exceed 0.56K.