Temperature sensing detection system for gas turbine

Abstract

The invention relates to the technical field of industrial high-temperature environment temperature precision detection, and discloses a temperature sensing detection system for a gas turbine, which comprises a front-end temperature sensing probe, a middle transmission channel and a rear-end processing module, a heat insulation shielding layer is arranged in the middle transmission channel to form a continuous anti-explosion sealing body, and auxiliary temperature sensors are arranged at the head end and the tail end of the middle transmission channel; and the rear-end processing module dynamically compensates nonlinear distortion caused by thermal resistance change of the transmission channel based on signals of the front-end probe and the auxiliary sensor. Through cooperation of a physical structure and an algorithm, the measured temperature and thermal environment fluctuation of the transmission channel are decoupled; the passive uncontrollable measurement drift is converted into a system internal parameter which can be monitored in real time, so that the authenticity of long-distance temperature signal transmission and the reliability of the system in extreme high-temperature and explosive environments are guaranteed.

Description

Technical Field

[0001] This invention relates to a temperature sensing and detection system for gas turbines, belonging to the field of precision temperature detection technology for industrial high-temperature environments. Background Technology

[0002] Currently, temperature detection is a fundamental technical means for achieving fire early warning and condition assessment. The industry generally uses platinum resistance thermometers as the front-end temperature sensing element, and the signal is led out through special high-temperature resistant cables. This method can meet basic monitoring requirements under normal high-temperature conditions. However, when a gas turbine operates under high-load conditions, the ambient temperature inside its compartments can reach 400°C. At this level, the changes in the physical properties of the signal transmission channel itself become the main factor affecting the measurement accuracy. The resistivity of the conductor of the transmission cable will show a significant nonlinear increase with the increase of temperature. As a result, the signal generated by the platinum resistance thermometer at the front end will be subject to a nonlinear error that is dynamically changing with the path temperature after flowing through this transmission cable which is also at a high temperature. This causes the signal received at the back end to deviate from the true value, i.e., the temperature loss phenomenon occurs.

[0003] To address this issue, simply increasing the temperature resistance rating of the cable material can only ensure the integrity of its physical structure, but cannot eliminate its inherent resistance-temperature effect. Conventional back-end software compensation, on the other hand, cannot obtain the complex and dynamic actual temperature distribution along the transmission cable. Any compensation algorithm based on a fixed model is difficult to achieve continuous and effective correction, which creates a technical constraint: the measurement system intends to accurately measure the temperature of the target point, but its transmission channel itself becomes a source of interference with an uncertain state that continuously introduces measurement errors.

[0004] Specifically, existing technologies suffer from the following shortcomings: 1. The physical survivability and system safety of the transmission medium at high temperatures. The organic insulation materials of existing high-temperature resistant cables age and fail more rapidly at extreme temperatures, and their structure lacks explosion-proof properties, posing safety hazards in the gas turbine environment rich in combustible gases; 2. Nonlinear distortion and attenuation of signals transmitted through the transmission channel under high-temperature conditions. The nonlinear change in conductor resistance of the transmission cable with temperature leads to severe temperature loss, rendering the deployment of high-precision front-end probes meaningless; 3. The integration adaptability and long-term reliability of the system's back-end processing unit in high-temperature and explosion-proof environments. Simply combining back-end modules that are not heat-resistant or explosion-proof with high-performance front-ends results in significant performance shortcomings and reliability vulnerabilities in the system. Therefore, how to establish a temperature detection system that can actively monitor and compensate for the thermal errors of the transmission channel itself to ensure the accuracy of long-distance signal transmission in extreme high-temperature and explosive environments is the technical problem to be solved by this invention. Summary of the Invention

[0005] This invention provides a temperature sensing detection system for gas turbines, the main purpose of which is to solve the problem of nonlinear distortion of temperature measurement signals caused by changes in the physical properties of the signal transmission channel itself in extreme high-temperature and explosive environments.

[0006] To achieve the above objectives, the present invention provides a temperature sensing detection system for a gas turbine, comprising: Front-end temperature sensor; The intermediate transmission channel includes a mineral-insulated cable, a metal protective sleeve fitted over the mineral-insulated cable, and a heat-insulating shielding layer disposed between the mineral-insulated cable and the metal protective sleeve. The two ends of the mineral-insulated cable are respectively connected to the shell of the front-end temperature sensing probe and the explosion-proof shell of the rear-end processing module through explosion-proof joints to form a continuous rigid explosion-proof seal for constraining internal heat transfer. A first auxiliary temperature sensor and a second auxiliary temperature sensor are respectively disposed at the first end of the mineral-insulated cable near the front-end temperature sensing probe and the second end near the rear-end processing module. The back-end processing module uses a high-temperature resistant substrate for its internal circuitry, and forms a heat conduction path with the explosion-proof shell of the back-end processing module via a thermally conductive potting material. The back-end processing module is configured to: receive the raw temperature signal from the front-end temperature sensor and the real-time temperatures of the first and second ends measured by the first and second auxiliary temperature sensors in each control cycle; calculate a correction amount to compensate for the nonlinear distortion of the raw temperature signal caused by the change in thermal resistance in the intermediate transmission channel based on the real-time temperatures of the first and second ends and a pre-stored attenuation model that takes the length of the intermediate transmission channel and the temperature resistance characteristics of the conductor as input; and apply the correction amount to correct the raw temperature signal to output the compensated temperature value.

[0007] Preferably, the attenuation model pre-stored in the back-end processing module is a database that takes the length parameter of the intermediate transmission channel, the temperature coefficient of resistance of the conductor material of the mineral insulated cable, and historical operating condition data as core input parameters. This database is used to construct a nonlinear mapping relationship between the nonlinear distortion of the original temperature signal and the real-time temperature of the first end and the second end.

[0008] Preferably, the calculation formula for the back-end processing module when calculating the correction amount is determined as follows: ,in, The value of the correction quantity in the resistance domain, This is a sensitivity coefficient calibrated based on historical operating data to characterize the change in the overall thermal resistivity of mineral-insulated cables. The preset length of the intermediate transmission channel. and These are the real-time temperatures measured by the first auxiliary temperature sensor and the second auxiliary temperature sensor, respectively. This is a preset reference temperature value.

[0009] Preferably, the heat insulation shielding layer is a structure composed of alternating layers of nanoporous aerogel heat insulation material and metal foil reflective layer. The nanoporous aerogel heat insulation material layer is used to suppress heat conduction and heat convection, and the metal foil reflective layer is used to block heat radiation.

[0010] Preferably, the internal circuit of the back-end processing module uses a ceramic-based copper-clad laminate as a high-temperature resistant substrate, and the thermally conductive potting material is silicone gel. The silicone gel completely covers the ceramic-based copper-clad laminate and the electronic components on it, and forms a heat conduction path between the electronic components and the explosion-proof shell.

[0011] Preferably, the explosion-proof joint is an explosion-proof threaded joint, the engagement length of the explosion-proof threaded joint is not less than 20mm, and the maximum gap of its explosion-proof mating surface is not greater than 0.15mm.

[0012] Preferably, the metal sheath of the mineral-insulated cable is made of Inconel nickel alloy material, and the metal protective sleeve is a stainless steel corrugated pipe.

[0013] Preferably, the front-end temperature sensing probe is a Pt1000 platinum resistance thermometer, and both the first auxiliary temperature sensor and the second auxiliary temperature sensor are Pt100 platinum resistance thermometers.

[0014] Preferably, the back-end processing module is also configured to perform online calibration of the historical operating condition data in the attenuation model based on the measured values ​​of the external standard temperature measuring device at multiple different temperature points after the system is installed on site, so as to optimize the nonlinear mapping relationship.

[0015] Preferably, the hardware and algorithms of the back-end processing module are configured to be located within the gas turbine nacelle at a depth of 300 meters. Up to 400 Within the ambient temperature range, through compensation of the correction amount, the overall measurement error of the compensated temperature value output by the system is less than ±1.5%.

[0016] Compared with the prior art, the beneficial effects of the present invention are: 1. A working mechanism is established to separate the temperature measurement results from the thermal environment fluctuations of the transmission channel itself. By setting first and second auxiliary temperature sensors at the beginning and end of the mineral-insulated cable respectively, the temperature status at both ends of the transmission channel is acquired in real time. This status information is used by the back-end processing module to dynamically adjust the compensation amount of the front-end temperature probe signal. This transforms the measurement drift introduced by the change in conductor resistivity at high temperatures into an uncontrollable interference variable, which is monitored and offset in real time as an internal parameter of the system. The authenticity of the measurement signal is no longer subject to the complex temperature distribution on the transmission path.

[0017] 2. Through the synergy of physical structure and signal processing, a prerequisite for stable operation of the dynamic compensation algorithm in the back-end processing module is created. The heat insulation shield layer set between the mineral-insulated cable and the metal protective sleeve slows down the rate and amplitude of heat transfer from the external environment to the internal mineral-insulated cable, making the change in the resistance-temperature characteristics of the cable conductor more gradual. This more gradual change in physical characteristics allows the adaptive compensation algorithm built into the back-end processing module to perform corrections within a more convergent operating range, avoiding the possibility of compensation model failure or oscillation problems caused by drastic changes in physical signals.

[0018] 3. The signal conditioning, analog-to-digital conversion, and nonlinear compensation processes are moved forward to an explosion-proof structure integrated with the front-end temperature sensor. The back-end processing module is directly connected to the intermediate transmission channel via an explosion-proof connector. Its internal circuit board and components are integrated with the explosion-proof shell through thermally conductive potting material. This structure allows the original uncompensated weak resistance signal to be converted into a stable digital signal within a very short path, avoiding secondary distortion caused by electromagnetic interference or line voltage drop during long-distance transmission to a safe area, thus ensuring the final signal quality of the system output. Attached Figure Description

[0019] Figure 1 This is a block diagram illustrating the working principle of the dynamic compensation of the temperature sensing detection system of the present invention. Figure 2 This is a verification curve showing the measurement accuracy of the system of the present invention under dynamic high temperature environment; Figure 3 This is a schematic diagram of the integrated explosion-proof deployment of the system of the present invention in the gas turbine nacelle. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the present invention clearer, the present 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 present invention and are not intended to limit the scope of protection of the present invention.

[0021] The temperature sensing detection system for gas turbines disclosed in this invention is applied to working environments such as the internal compartments of industrial gas turbines where there are continuous high temperatures and potentially combustible gases. Its function is to perform long-term, stable, and highly accurate temperature measurement at specific monitoring points. The system consists of a front-end temperature sensing probe, an intermediate transmission channel, and a back-end processing module. The three are mechanically connected by an explosion-proof joint to form a continuous, rigid, explosion-proof seal. The front-end temperature sensing probe converts the contact temperature into a raw resistance signal. The intermediate transmission channel leads this signal out from the high-temperature front end. The back-end processing module receives the signal and performs signal conditioning, analog-to-digital conversion, and nonlinear distortion compensation calculations, ultimately outputting a corrected, standardized digital signal that reflects the actual temperature of the front end.

[0022] In a specific application, such as monitoring the temperature of high-temperature gas or load-bearing bearings downstream of the turbine section of a gas turbine, the system's front-end temperature sensor is placed directly at the object being measured, while the back-end processing module is fixed at a remote location outside the casing for easy wiring. This inevitably means that the intermediate transmission channel between the two traverses a considerable distance where the ambient temperature can reach 400°C. In high-temperature regions, the resistivity of the conductor in the signal transmission cable exhibits a significant nonlinear increase with rising ambient temperature. This results in a dynamic nonlinear error, related to the path temperature, being added to the original temperature signal flowing through this high-temperature path. To address this, the intermediate transmission channel of this invention physically comprises a mineral-insulated cable, an external metal protective sheath, and a heat-insulating shielding layer positioned between the mineral-insulated cable and the metal protective sheath. In this composite structure, the mineral-insulated cable utilizes an inorganic material system, such as Inconel alloy as the metal sheath, filled internally with compacted magnesium oxide powder as the insulation layer, and fitted with precision-machined explosion-proof threaded connectors at both ends. Its meshing length is not less than 20mm and the maximum gap of the explosion-proof joint surface is not greater than 0.15mm. Its inorganic material structure and sealing connection method jointly ensure the physical integrity of the transmission medium at high temperatures and the overall explosion-proof safety of the system. At the same time, the heat insulation shielding layer wrapped around the mineral insulated cable is composed of alternating layers of nanoporous aerogel heat insulation material and metal foil reflective layer. This layer blocks the radiative and convective heat of the external environment, providing a working environment with a more gradual temperature gradient for the internal mineral insulated cable. This measure physically suppresses the possibility of large fluctuations in conductor resistance due to severe external thermal disturbances, providing a stable signal basis for subsequent algorithm compensation.

[0023] To transform the passively introduced measurement drift into a calculable and offsettable intra-system parameter, the present invention further includes a first auxiliary temperature sensor and a second auxiliary temperature sensor, respectively located at the first end of the mineral-insulated cable near the front-end temperature probe and the second end near the back-end processing module, to acquire the temperature status at both ends of the physical path of the intermediate transmission channel in real time. The back-end processing module is configured to synchronously receive the raw temperature signal from the front-end temperature probe (e.g., a Pt1000 platinum resistance thermometer) and the real-time temperature at the first end measured by the first and second auxiliary temperature sensors (e.g., both Pt100 platinum resistance thermometers) in each control cycle. Real-time temperature at the second end The back-end processing module integrates an adaptive compensation algorithm unit. This unit dynamically calculates a correction amount based on a pre-stored attenuation model to compensate for the nonlinear distortion of the original temperature signal caused by changes in thermal resistance within the transmission channel. This attenuation model takes the temperature coefficient of resistance of the conductor material along the length of the intermediate transmission channel and historical operating data as inputs to construct a mapping relationship between the nonlinear distortion of the original signal and the real-time temperatures at both ends of the channel. In a specific calculation, the characteristic value of this correction amount in the resistance domain is... It was identified as: ,in, The preset length of the intermediate transmission channel, for example, 5m. The preset reference temperature value, for example, 20. , This is a calibrated sensitivity coefficient characterizing the overall thermal resistivity change of mineral-insulated cables. The determination can be completed through an offline calibration process: a standard length of transmission channel assembly is placed in a temperature-controlled chamber, and the temperature at both ends is precisely controlled. and Simultaneously, a high-precision bridge is used to measure the resistance change of its internal conductors at multiple temperature points (e.g., from 50°C). Up to 400 50 By taking a single point and repeating the measurement, a stable value can be obtained through data fitting. Values, for example =0.002 In practical work, if the actual temperature measured by the front-end temperature sensor is 600... The corresponding theoretical resistance value is 3137.1. However, because the transmission channel is at a high temperature, for example... , Due to environmental factors, signal attenuation occurs, and the original resistance value of the receiver at the back end may be 3133.8. At this point, the compensation algorithm unit calculates the average temperature of the channel as follows: And calculate the correction amount according to the formula. Finally, the back-end processing module adds this correction amount to the original signal, i.e. The final temperature value of 600 was calculated using this corrected resistance value. This completes the dynamic compensation for thermally induced nonlinear distortion.

[0024] To address the highly nonlinear temperature distribution along the intermediate transmission channel, the attenuation model can be constructed using a radial basis function (RBF) neural network. The specific offline training and online calibration procedures are as follows: To calibrate and determine the sensitivity coefficients of an independent temperature sensing system... In the specific value calibration platform, an independent and controllable heat source is applied to the middle of a transmission channel of known length to generate a sample of nonlinear temperature distribution along the channel. The actual resistance change after integration is measured by multiple independent thermocouples deployed along the channel. and multiple groups As network input, the corresponding As the expected output of the network, after forming a training sample set, the network weights are adjusted using the standard backpropagation algorithm until the root mean square error of the output is lower than a preset threshold. After the system is installed on site, the benchmark data set containing the measured values ​​of the external standard temperature measuring device is used as a high-weight calibration sample. The Levenberg-Marquardt algorithm is used to fine-tune the trained network weights one or more times. The purpose of this algorithm is to minimize the residual between the model output and the actual measured distortion on site, so that the attenuation model matches the actual heat conduction characteristics of the specific installation location.

[0025] Historical operating data includes timestamps, the original resistance value of the front-end temperature probe, and the temperatures of the first and second auxiliary temperature sensors. and This includes a time-series database of the main control system output parameters (such as turbine speed, fuel supply rate, and compressor outlet pressure) during gas turbine operation. This data is used to construct a multivariate compensation model. In practical applications, in addition to... and In addition to the basic inputs of the model, parameters such as turbine speed are also used as additional input variables. The model uses pre-calibrated weighting coefficients to associate the specific operating states represented by these additional variables with a set of typical nonlinear temperature distribution patterns on the transmission channel. This method enables the calculation of the correction amount to not only respond to the real-time temperature at both ends of the channel, but also to take into account the predictable heat distribution influence component determined by the overall machine operating state, which in particular improves the compensation response speed and accuracy during rapid switching of operating conditions.

[0026] To ensure the long-term reliable operation of the aforementioned compensation algorithm and signal processing circuit in a high-temperature explosion-proof environment, the internal circuitry of the back-end processing module utilizes a high-temperature resistant substrate. A thermally conductive potting compound forms a heat conduction path between the substrate and the module's explosion-proof housing. Specifically, the circuit board can be a ceramic-based copper-clad laminate. The analog-to-digital converter, microprocessor, and power supply chips mounted on it are all industrial-grade or higher-grade high-temperature components. After assembly, a high-thermal-conductivity silicone gel is used to fully encapsulate the entire cavity. This silicone gel completely covers the ceramic-based copper-clad laminate and its electronic components, forming a continuous heat conduction path between the electronic components and the explosion-proof housing. This design, on the one hand, utilizes the fixing and sealing effect of the potting compound to improve the internal circuitry's vibration resistance, moisture resistance, and corrosion resistance; on the other hand, it efficiently conducts the heat generated by all electronic components during operation to the metal explosion-proof housing, which has a large surface area and high heat capacity, and then dissipates the heat. This ensures that the junction temperature of the internal core components remains within its allowable operating range, allowing the entire system to operate reliably at temperatures up to 300°C. Up to 400 Within the ambient temperature range, the overall measurement error of its output compensated temperature value is less than ±1.5%.

[0027] Example 1: In the case of a heavy-duty gas turbine operating at full load, the ambient temperature inside its compartments locally rises to nearly 400°C due to heat accumulation. At this point, the reading displayed by the back-end control system of a conventional platinum resistance thermometer used to monitor the turbine outlet exhaust temperature slowly decreased from a stable critical operating point of 750°C. Gradually drifted to 730 This reading indicates a deviation in the gas turbine's combustion state. Adjusting combustion based on this data could lead to excessive fuel injection, posing a risk of overheating and damaging the turbine blades. Ignoring this data, however, cannot rule out the possibility that the actual temperature at the front-end measuring point has indeed decreased, creating uncertainty in operational decisions. In this scenario, a temperature sensing system was deployed, with its front-end temperature probe installed at the same measuring point. A 5-meter-long intermediate transmission channel traverses the aforementioned 400... In high-temperature areas; when the ambient temperature of the cabin rises, the first auxiliary temperature sensor and the second auxiliary temperature sensor, located at both ends of the mineral-insulated cable, respectively measure the temperature of the first end near the front end of the channel. Rise to 390 Temperature at the second end near the rear end Rise to 350 This data is transmitted to the back-end processing module in real time. Simultaneously, the raw resistance signal received by the back-end processing module from the front-end temperature probe is attenuated due to the thermal increase in the resistance of the conductor in the intermediate transmission channel. If this attenuated signal is directly calculated, the corresponding temperature reading is also 730. .

[0028] At this point, the system's built-in adaptive compensation algorithm unit begins to operate. This unit first utilizes the thermal insulation shielding layer to slow down the heat transfer from the external environment to the mineral-insulated cable, making the change in the resistance-temperature characteristics of the cable conductor more gradual. This provides the compensation algorithm with a raw signal input with a relatively small disturbance amplitude. Then, the algorithm unit retrieves the real-time readings from the first and second auxiliary temperature sensors. and Based on the pre-stored attenuation model and compensation formula The calculation process calculates the resistance domain correction caused by the change in thermal resistance of the transmission channel under the current operating conditions. This calculation process transforms the complex temperature distribution problem along the path into a system parameter correction problem that can be characterized by the endpoint states by monitoring the temperature conditions at both ends of the path. After obtaining the correction value, the back-end processing module applies it to the received original resistance signal for correction, and the final compensated temperature value is stably maintained at 750°C. This reading is consistent with the state characterized by other operating parameters of the gas turbine; thus, the measured value of the front-end temperature probe is no longer distorted by the fluctuation of the thermal environment in the intermediate transmission channel. The composite intermediate transmission channel, consisting of mineral-insulated cables, thermal shielding layers, and metal protective sleeves, provides the physical premise for the stable operation of the back-end algorithm, while the dynamic compensation algorithm based on the temperature state at both ends of the channel ensures the accuracy of the final data of the high-precision front-end measurement. The temperature data finally output by the system provides operators with decision-making information that can be relied upon.

[0029] Example 2: To objectively verify the effect of the temperature sensing detection system of the present invention in suppressing nonlinear distortion of signal transmission under simulated high-temperature environment, the following experimental platform was built. The platform includes a tubular heating furnace with a temperature control range of room temperature to 500°C. Temperature control accuracy is ±1 This is used to simulate the high-temperature environment of the intermediate transmission channel; a dry block furnace with a temperature control range from room temperature to 800°C. The stability is ±0.1. This is used to apply a stable reference temperature to the front-end temperature sensor, and a multi-channel data acquisition system with a temperature resolution of 0.01. The sampling frequency was 1Hz to synchronously record the output data of all sample groups. Two sample groups were set up for the experiment: a control group and the sample group of the present invention. The control group used the same Pt1000 front-end temperature probe and 5m long mineral-insulated cable as the sample group of the present invention, but it did not include an external heat-insulating shielding layer or metal protective sleeve, nor did it have a first auxiliary temperature sensor and a second auxiliary temperature sensor for monitoring the channel temperature, and its adaptive compensation algorithm in the back-end processing module was disabled. The sample group of the present invention was a complete temperature sensing detection system constructed according to a specific implementation method, and its adaptive compensation algorithm in the back-end processing module was activated. During the experiment, the probe reference temperature was set to 500.00℃. With 700.00 Two working points, the ambient temperature of the channel is controlled by a tubular heater from 25°C. Start with 50 The temperature was gradually increased to 400 degrees Celsius, using a step size. Each temperature point was kept at that temperature for 30 minutes until the system reached thermal equilibrium before data recording was performed. The experimental procedure is as follows: First, the front-end temperature sensors of both sample groups were simultaneously placed into an atmosphere that had stabilized at 500.00. In a dry bulk furnace, the intermediate transfer channel of the two sample groups was passed parallel to each other through a tubular furnace with an initial temperature of 25°C. At this point, the initial readings of both sample groups were 500.02. Within this range, the temperature is basically consistent with the reference temperature; subsequently, the tubular heating furnace is started, and when the ambient temperature in the channel rises to 300... At that time, the control group's reading dropped to 489.21. However, the compensated reading of the sample group of this invention still remained at 499.81. ; at the end of the test 400 At that time, the control group's reading further decreased to 484.86. The deviation from the reference temperature exceeds 15. The compensated reading of the sample group of this invention is 500.15. The deviation is less than 0.2. It should be noted that, during this process, the uncompensated original readings of the sample group of this invention were at 400. The time was 490.40 The deviation was smaller than that of the control group, indicating that the heat insulation shielding layer played a part in passive heat insulation. However, the accuracy of the final reading was the result of compensation and correction by the back-end processing module based on the real-time data of the first auxiliary temperature sensor and the second auxiliary temperature sensor.

[0030] To verify the effect at higher temperatures, the reference temperature of the dry block oven was adjusted to 700.00. The above heating process was repeated, and a similar trend was obtained; the ambient temperature in the channel was 25°C. In the initial state, the readings of both sample groups were close to 700.00. When the ambient temperature in the passage rises to 400 At that time, the control group's reading dropped to 681.55. Its measurement error reached -2.64%, while the final output temperature of the sample group after compensation was 700.23°C. The measurement error remained within +0.03%; this test data confirms that the intermediate transmission channel was exposed to temperatures up to 400... In an external environment, an uncompensated temperature sensing system will produce a measurement deviation that increases with increasing ambient temperature. The temperature sensing detection system of this invention, by combining physical insulation with dynamic algorithm compensation under dual-end temperature monitoring, can effectively suppress this deviation, maintaining the accuracy of its final output temperature in simulated high-temperature industrial environments. During the experiment in this embodiment, when the temperature of the tubular furnace stabilized at 400°C... Meanwhile, a K-type thermocouple was used to simultaneously measure the surface temperature of the explosion-proof housing of the back-end processing module of the present invention sample group, and it was recorded that its surface temperature stabilized at 85°C after long-term operation. Up to 95 During this period, the data acquisition system showed that the internal microprocessor of the module continued to work normally, and the output data stream of its compensation calculation was stable. There were no crashes, restarts or data jumps caused by high temperature. This result verifies that the back-end processing module can effectively dissipate the heat generated by the internal electronic components through the heat conduction path formed by the ceramic-based circuit board and thermally conductive potting material and the explosion-proof shell, so that its core junction temperature is maintained within the allowable operating range.

[0031] Example 3: This example combines Figures 1 to 3 A description of a temperature sensing detection system for gas turbines, such as... Figure 1 As shown, the physical temperature of the object being measured is first converted into a raw resistance signal by the front-end temperature sensing probe. When this signal flows through the intermediate transmission channel, it is superimposed with thermal distortion due to the high-temperature environment, forming a raw signal containing thermal distortion. At the same time, the first auxiliary temperature sensor and the second auxiliary temperature sensor, respectively set at the beginning and end of the intermediate transmission channel, monitor and output the real-time temperature of the first end in real time. Real-time temperature at the second end The signal receiving and acquisition unit in the back-end processing module receives the aforementioned raw signal and the real-time temperature signals from both ends. Its built-in adaptive compensation algorithm unit uses a pre-stored attenuation model and utilizes the real-time input... and The system calculates a correction value to offset thermally induced nonlinear distortion. The signal correction and output unit applies this correction value to correct the original data, and finally generates a compensated temperature value, which is output to the main control system in the form of a standardized digital signal.

[0032] like Figure 2 As shown, the horizontal axis represents time in minutes, and the vertical axis on the left represents the measured temperature. The right vertical axis represents the ambient temperature. The actual temperature curve in the figure represents the real temperature change of the tested object, while the ambient temperature curve simulates the temperature fluctuation of the environment in which the intermediate transmission channel is located. The compensated output curve is the final temperature reading output by the system of this invention. As can be seen from the figure, although the ambient temperature underwent drastic changes during the test and reached nearly 400 degrees Celsius... Despite the high temperature, the compensated output curve of this system can still follow the actual temperature curve with high accuracy. This shows that the system effectively overcomes the measurement distortion caused by the transmission channel being in a harsh thermal environment through its internal compensation mechanism, ensuring the authenticity and reliability of the final output data.

[0033] like Figure 3 As shown, this compartment is a place where the temperature can reach 400 degrees Celsius. In harsh environments with high risk of explosion and strong electromagnetic interference, the front-end temperature sensing probe is placed directly at the object being measured, such as the high-temperature heat source or the point being measured after the turbine section of the gas turbine. The back-end processing module is fixed at a relatively remote position inside the cabin. The two are connected by a composite intermediate transmission channel consisting of mineral-insulated cables, a heat-insulating shielding layer, and a metal protective sleeve. All components are connected by explosion-proof joints to form a continuous, rigid, explosion-proof seal. The back-end processing module transmits the compensated, standardized digital signal to the external main control room or DCS system to monitor the operating status.

[0034] Example 4: To calibrate and determine the sensitivity coefficient of an independent temperature sensing system. Specific values ​​are assigned for use by the adaptive compensation algorithm in its backend processing module, and the following calibration procedure can be executed; this procedure is performed in a dual-temperature zone programmable temperature and humidity test chamber, which can independently control the temperature of two isolated areas within the chamber, with a temperature control accuracy of ±0.5. Additionally, a 6.5-digit digital multimeter with a resistance measurement resolution of 0.001Ω is required, along with two calibrated standard Class A Pt100 thermometers; the calibration is performed on a set of intermediate transmission channels to be shipped. The temperature sensing system is 5.0m long. Before calibration, the entire intermediate transmission channel of the system is placed inside the test chamber, with its two ends located in two independent temperature zones. The front-end temperature probe and the back-end processing module are placed in the ambient temperature environment outside the chamber. First, both temperature zones of the test chamber are set to the reference temperature. That is, 20.0 After the overall system temperature stabilizes, use a digital multimeter to measure and record the initial loop resistance of the mineral-insulated cable conductor. .

[0035] Subsequently, the temperature corresponding to the first temperature zone, i.e., the first end of the transmission channel, is maintained at [temperature value missing]. The temperature of the second temperature zone, i.e., the second end of the transmission channel, remains unchanged. Set it to 120.0 sequentially. 220.0 320.0 With 420.0 Four test points; at each test point, maintain the temperature for 30 minutes until the temperature distribution of the transmission channel stabilizes, then record the current total loop resistance. At the same time, a standard Pt100 thermometer was used to verify the actual temperatures of the two temperature zones to obtain accurate results. and Value; for each test point Its resistance change Depend on The difference between its channel average temperature and the reference temperature was obtained. Then by Therefore, the sensitivity coefficient at that test point can be calculated by transforming the compensation formula. ;exist It is 320.0 If the test point is measured compared to It increased by 2.940Ω, and after verification and They are 20.0 respectively. With 320.0 ,but for Correspondingly ; obtained by calculating all four test points The arithmetic mean of the values ​​yields the final sensitivity coefficient of the system. The calibration obtained The value will be written as a firmware parameter into the non-volatile memory of its back-end processing module, providing a data basis for subsequent compensation calculations under actual working conditions.

[0036] Example 5: After the temperature sensing system is physically installed at the gas turbine site, an online calibration procedure is performed to match the pre-stored attenuation model with the actual heat transfer characteristics of the specific installation location. This procedure requires an external, calibrated standard temperature measuring device, with its sensing end positioned close to the front-end temperature probe of the present invention. The gas turbine is started and sequentially and stably operated at multiple operating conditions, including idle, medium load, and full load. At each operating condition, after the cabin temperature field and all temperature readings have reached a stable state, the reference temperature measured by the standard temperature measuring device, the compensated temperature value output by the back-end processing module of the present invention, the original temperature signal before compensation, and the real-time temperatures of the first auxiliary temperature sensor and the second auxiliary temperature sensor are recorded simultaneously. and These arrays, containing data on reference temperature and internal system state parameters corresponding to different operating conditions, are used to fit and optimize the pre-stored attenuation model in the back-end processing module, thereby adjusting the nonlinear distortion of the original temperature signal. , The nonlinear mapping relationship between them.

[0037] To address sensor malfunctions, the back-end processing module performs temperature compensation calculations and verifies the validity of signals from the first and second auxiliary temperature sensors during each control cycle. This verification logic includes checking whether the sensor signals are within a preset physical range and whether their rate of change exceeds an allowable threshold. When any auxiliary temperature sensor is detected to have open-circuit, short-circuit, or continuously unchanged readings, the system switches to a preset safe operating mode. In this mode, the back-end processing module suspends compensation calculations to avoid calculating incorrect correction values ​​due to unreliable input data sources. Simultaneously, the system sends a sensor malfunction alarm signal to the main control room and switches its temperature output to the uncompensated raw temperature signal, providing operators with direct, raw measurement information.

[0038] Example 6: During the final design phase of the temperature sensing system, the following offline optimization and verification procedure was performed to determine the parameters of key physical structures. For the thermal insulation shielding layer within the intermediate transmission channel, the optimization objective was to minimize the equilibrium temperature of the outer surface of the mineral-insulated cable's metal sheath under given external thermal shock conditions, while also considering the overall outer diameter of the transmission channel and material costs. This optimization process employed the finite element thermal analysis method, applying a 400°C thermal stress to the outer wall of the metal protective sleeve in the model. The steady-state heat source was analyzed by parametric scanning calculations on the thickness (range of 1 mm to 3 mm) of the nanoporous aerogel layer in the thermal insulation shielding layer and the number of composite layers (range of 1 to 5 pairs) formed with the metal foil reflective layer. The results showed that when the number of composite layers exceeded 3 pairs or the thickness of the aerogel layer was greater than 2 mm, the marginal improvement of its thermal performance slowed down, while the overall outer diameter and cost increased significantly. Based on this, the structure of the thermal insulation shielding layer was determined to be three pairs of composite layers, in which each pair of composite layers included a 2 mm thick nanoporous aerogel thermal insulation material layer and a 0.05 mm thick metal foil reflective layer. This structure is an equilibrium solution under the above multi-objective constraints.

[0039] For the explosion-proof threaded joints connecting various components, their geometric dimensions are determined based on the design specifications for electrical equipment used in explosive atmospheres. To make the system suitable for operating conditions containing specific flammable gases in the gas turbine compartment, the parameters of its explosion-proof mating surface are set according to the design requirements for specific explosion-proof levels in such environments. Among them, the thread engagement length of not less than 20 mm and the maximum engagement clearance of not more than 0.15 mm are used to construct a narrow pressure relief and cooling channel. Its function is that if the infiltrated flammable gas is accidentally ignited inside the system, the resulting high-temperature and high-pressure gas flow will exchange heat with the mating surface when it escapes along the thread clearance, reducing its temperature to below the auto-ignition point of the flammable gas before reaching the external environment, thereby blocking the flame propagation path. This is the physical basis for the safety function of this continuous rigid explosion-proof seal.

[0040] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

Claims

1. A temperature sensing detection system for a gas turbine, characterized in that, include: Front-end temperature sensor; The intermediate transmission channel includes a mineral-insulated cable, a metal protective sleeve fitted over the mineral-insulated cable, and a heat-insulating shielding layer disposed between the mineral-insulated cable and the metal protective sleeve. The two ends of the mineral-insulated cable are respectively connected to the shell of the front-end temperature sensing probe and the explosion-proof shell of the rear-end processing module through explosion-proof joints to form a continuous rigid explosion-proof seal for constraining internal heat transfer. A first auxiliary temperature sensor and a second auxiliary temperature sensor are respectively disposed at the first end of the mineral-insulated cable near the front-end temperature sensing probe and the second end near the rear-end processing module. The back-end processing module uses a high-temperature resistant substrate for its internal circuitry, and forms a heat conduction path with the explosion-proof shell of the back-end processing module via a thermally conductive potting material. The back-end processing module is configured to: receive the raw temperature signal from the front-end temperature sensor and the real-time temperatures of the first and second ends measured by the first and second auxiliary temperature sensors in each control cycle; calculate a correction amount to compensate for the nonlinear distortion of the raw temperature signal caused by the change in thermal resistance in the intermediate transmission channel based on the real-time temperatures of the first and second ends and a pre-stored attenuation model that takes the length of the intermediate transmission channel and the temperature resistance characteristics of the conductor as inputs; and apply the correction amount to correct the raw temperature signal.

2. The temperature sensing detection system for a gas turbine according to claim 1, characterized in that, The pre-stored attenuation model in the back-end processing module is a database that uses the length parameter of the intermediate transmission channel, the temperature coefficient of resistance of the conductor material of the mineral insulated cable, and historical operating condition data as core input parameters. This database is used to construct a nonlinear mapping relationship between the nonlinear distortion of the original temperature signal and the real-time temperature of the first and second ends.

3. The temperature sensing detection system for a gas turbine according to claim 1, characterized in that, When calculating the correction amount, the back-end processing module uses the following formula: ,in, The value of the correction quantity in the resistance domain, This is a sensitivity coefficient used to calibrate and characterize the change in the overall thermal resistivity of mineral-insulated cables based on historical operating data. The preset length of the intermediate transmission channel. and These are the real-time temperatures measured by the first auxiliary temperature sensor and the second auxiliary temperature sensor, respectively. This is a preset reference temperature value.

4. The temperature sensing detection system for a gas turbine according to claim 1, characterized in that, The heat insulation shielding layer is a structure composed of alternating layers of nanoporous aerogel heat insulation material and metal foil reflective layer.

5. A temperature sensing detection system for a gas turbine according to claim 1, characterized in that, The internal circuit of the back-end processing module uses a ceramic-based copper-clad laminate as a high-temperature resistant substrate, and the thermally conductive potting material is silicone gel. The silicone gel covers the ceramic-based copper-clad laminate and the electronic components on it, and forms a heat conduction path between the electronic components and the explosion-proof shell.

6. The temperature sensing detection system for a gas turbine according to claim 1, characterized in that, The explosion-proof joint is an explosion-proof threaded joint. The engagement length of the explosion-proof threaded joint is not less than 20mm, and the maximum gap between its explosion-proof mating surfaces is not greater than 0.15mm.

7. A temperature sensing detection system for a gas turbine according to claim 1, characterized in that, The metal sheath of the mineral-insulated cable is made of Inconel nickel alloy, and the metal protective sleeve is a stainless steel corrugated pipe.

8. A temperature sensing detection system for a gas turbine according to claim 1, characterized in that, The front-end temperature sensing probe is a Pt1000 platinum resistance thermometer, and both the first auxiliary temperature sensor and the second auxiliary temperature sensor are Pt100 platinum resistance thermometers.

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