Cooling system for aero-engine high-pressure turbine telemetry device based on coupling of fuel oil and air and control method thereof

Abstract

The application belongs to the technical field of aero-engine thermal management, and provides a high-pressure turbine telemetering device cooling system based on fuel oil and air coupling and a control method thereof. The system comprises an air source supply and air cooling subsystem and a fuel oil cooling subsystem. The former adopts a double-layer sleeve pipe arranged in the turbine rear end exhaust branch plate: the inner pipe transports the main cooling air flow, and the annular cavity transports the isolation air flow; the main air flow is divided into three paths, which are respectively used for the rear bearing cavity sealing, the inner cone cavity heat insulation and the telemetering device electronic element impact cooling. The latter cools the oil through the external fuel oil-oil radiator, and the cooled oil returns to the rear bearing cavity to cool the turbine rear shaft journal; the telemetering device is fixed on the stator structure adjacent to the journal, the installation base body is thermally coupled with the journal, and indirect cooling is realized. The system effectively guarantees the reliable operation of the telemetering device in the high-temperature environment through the synergistic effect of direct air cooling and indirect oil cooling.

Description

Technical Field

[0001] This invention belongs to the field of aero-engine thermal management technology, and relates to a cooling system and control method for a high-pressure turbine telemetry device of an aero-engine based on fuel-lubricating oil and air coupling. Background Technology

[0002] As a core power component, the high-pressure turbine of an aero-engine typically operates in extreme environments such as high temperature, high pressure, high speed, and strong gas scouring. In order to accurately obtain key parameters such as dynamic stress, transient temperature, and pressure of its rotating parts, telemetry devices (including sensors, signal transmission modules, etc.) are commonly used for non-contact measurement.

[0003] Telemetry devices are mostly located in the turbine rear journal area, where the ambient temperature far exceeds the safe operating limits of electronic components. Currently, a single cooling solution is often used to cool the telemetry devices in the turbine rear journal area, but this solution has the following shortcomings in extreme thermal environments:

[0004] 1. The single air cooling solution relies on the test bench for air supply. The temperature rise of the air along the high-pressure turbine in the high-temperature environment is too high, which greatly reduces the cooling efficiency of the electronic components of the telemetry device. Moreover, the air supply is limited by the test bench system and cannot adapt to the instantaneous heat load fluctuations of the engine, resulting in poor cooling stability. 2. In the single fuel / lubricating oil cooling scheme, the initial temperature of the lubricating oil in the turbine rear chamber is relatively high and the heat capacity is limited. It is not able to buffer the pulsed heat load, making it difficult to achieve continuous temperature control of the mounting substrate. This can easily lead to excessive heat conduction from the high-temperature substrate to the telemetry device.

[0005] Therefore, there is an urgent need for a coupled cooling system and corresponding control method that integrates the cooling advantages of air and lubricating oil and has dynamic regulation capabilities to ensure the reliable operation of telemetry devices under harsh conditions. Summary of the Invention

[0006] To address the technical problems of insufficient cooling, uncontrolled temperature rise, and inadequate dynamic response capabilities in existing high-pressure turbine telemetry devices for aero-engines under high-temperature and high-heat-load environments due to a single cooling method, this invention discloses a cooling system for a high-pressure turbine telemetry device for aero-engines based on fuel-lubricating oil and air coupling. This system achieves heat insulation and staged utilization of the air path through a double-layered sleeve air duct structure, and actively regulates the lubricating oil temperature in conjunction with a fuel-lubricating oil radiator, constructing a coupled cooling mechanism that synergistically utilizes air and fuel-lubricating oil. This effectively ensures the long-term stable operation of the telemetry device under high-temperature and high-speed conditions.

[0007] Specifically, the system includes an air supply and air cooling subsystem and a fuel oil cooling subsystem.

[0008] Among them, the air supply and air cooling subsystem is used to directly cool the telemetry device and provide active heat insulation for the main cooling air. It includes a double-layer sleeve installed inside the high-temperature exhaust support plate at the rear end of the turbine. The inner tube of the double-layer sleeve forms the first airflow path for conveying the main cooling air, and the outer tube is sleeved outside the inner tube. The annular cavity between the two forms the second airflow path for conveying the isolation cooling air. The outlet end of the first airflow path is connected to three branches with different functions: The first branch is a sealing branch, which connects to the rear bearing cavity of the engine and is used to heat-insulate and seal the rear bearing cavity of the engine. The second branch is a heat insulation branch, which connects to the inner cone cavity behind the turbine and is used to isolate the high-temperature gas from the radiative heat transfer of the telemetry device. The third branch is a cooling branch, which connects to the gas collection ring cavity of the telemetry device and is used to perform impact cooling on the electronic components of the telemetry device.

[0009] The fuel-oil cooling subsystem includes a fuel-oil radiator located outside the engine. Its oil-side inlet is connected to the oil outlet pipe of the engine rear bearing cavity, and its oil-side outlet is connected to the engine oil return pipe. The oil cooled by the fuel-oil radiator flows back to the engine rear bearing cavity to cool the journal of the turbine rear shaft, thereby indirectly reducing the temperature of the mounting base of the telemetry device.

[0010] Furthermore, flow regulating valves are provided on the first airflow path, the second airflow path, and the fuel side pipeline of the fuel-oil cooler.

[0011] Furthermore, a first temperature sensor is provided on the lubricating oil outlet pipe of the engine rear bearing cavity to monitor the temperature of the lubricating oil flowing out of the engine rear bearing cavity; a second temperature sensor is provided on the housing of the telemetry device or in its immediate vicinity to monitor the operating temperature of the telemetry device.

[0012] Furthermore, the cooling branch is connected to multiple impact cooling holes on the mounting base of the telemetry device through the air collection ring cavity, so that the cooling air forms a uniform jet to impact the heating element of the telemetry device.

[0013] Furthermore, the temperature rise ΔT of the main cooling air along the path in the first airflow path is calculated using the following heat transfer model to evaluate the cooling efficiency: ; in, The wall temperature of the high-temperature exhaust support plate. The test bench is used to remotely measure the cooling air supply temperature; L is the effective length of the inner tube in the high-temperature zone. The specific heat capacity of air at constant pressure. The inner diameter of the inner tube. U is the air mass flow rate of the first air intake path, and U is the overall heat transfer coefficient.

[0014] Furthermore, before using the heat transfer model, the overall heat transfer coefficient is obtained by solving the flow-heat exchange coupling field in the gap between the inner tube, outer tube, and high-temperature exhaust support plate based on the pre-calibrated correlation or in real time.

[0015] Furthermore, the fuel mass flow rate through the fuel-oil radiator is calculated based on the following heat balance model to determine the fuel-side cooling requirement: ; in, For fuel mass flow rate, This refers to the mass flow rate of the lubricating oil. The specific heat capacity of lubricating oil at constant pressure. and These are the inlet and outlet temperatures of the lubricating oil, respectively. The specific heat capacity of fuel at constant pressure. and These are the inlet and outlet temperatures of the fuel, respectively. The heat transfer efficiency of the fuel-oil radiator.

[0016] This invention also provides a control method for the above-mentioned cooling system, the control method comprising the following steps: S1. Obtain the main cooling air supply temperature, high-temperature exhaust support plate wall temperature, inner pipe geometry, air mass flow rate and overall heat transfer coefficient, and calculate the friction temperature rise ΔT of the main cooling air from the inlet to the outlet based on the friction temperature rise model; when the friction temperature rise ΔT ≥ the temperature rise threshold, increase the gas flow rate of the first and second induced flow paths. S2. Obtain the lubricating oil inlet temperature, lubricating oil outlet temperature, lubricating oil mass flow rate, fuel inlet and outlet temperatures, fuel specific heat capacity, lubricating oil specific heat capacity and radiator heat transfer efficiency, calculate the required theoretical fuel mass flow rate based on the heat balance relationship, and dynamically adjust the actual fuel mass flow rate according to the lubricating oil outlet temperature so that the lubricating oil outlet temperature does not exceed the set temperature. S3. Monitor the operating temperature T_device of the telemetry device in real time; if the operating temperature T_device is greater than or equal to the set temperature, return to step S1 and / or step S2 to readjust the gas flow rate or fuel flow rate until the operating temperature T_device is less than the set temperature.

[0017] Furthermore, the actual fuel mass flow rate is 1.1 to 1.3 times the theoretical fuel mass flow rate.

[0018] Compared with the prior art, the beneficial effects that at least one technical solution adopted in the embodiments of this specification can achieve include at least: 1. The dual-path coupled cooling architecture, which consists of "air direct cooling device body and lubricating oil cooling mounting base", can suppress temperature rise simultaneously from both ends of the heat source and heat transfer path, thus overcoming the bottleneck of insufficient cooling capacity of a single medium.

[0019] 2. By adopting a double-layer sleeve structure and a friction-based temperature rise calculation method, the main cooling airflow can effectively suppress heat absorption and temperature rise in a high-temperature environment, thus significantly improving cooling efficiency.

[0020] 3. By constructing a complete calculation model that covers air cooling temperature rise and fuel-lubricating oil thermal balance, the system design is transformed from experience-based vectorized analysis, thereby improving design accuracy and reliability.

[0021] 4. Temperature sensors and flow control valves are arranged in each flow path, and closed-loop regulation of cooling flow is realized based on real-time feedback. It can flexibly respond to changes in heat load under different steady-state / transient operating conditions of the engine and has good robustness.

[0022] 5. The system architecture designed in this invention is clear, the components are mature (such as sleeves, radiators, valves, and sensors), and it is easy to integrate and implement in engineering. Moreover, its concept of combining coupled cooling and dynamic control can also be extended to the thermal management design of other high-temperature rotating components. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is an architectural diagram of the cooling system for a high-pressure turbine telemetry device for aero-engines based on fuel-lubricating oil and air coupling, as disclosed in this invention. Figure 2 This invention discloses the design flow of a cooling system for a high-pressure turbine telemetry device for aero-engines based on fuel-lubricating oil and air coupling. Figure 3 This is a control flowchart of the cooling system of the high-pressure turbine telemetry device for an aero-engine disclosed in an embodiment of the present invention. Detailed Implementation

[0025] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0026] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. This application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, in the absence of conflict, the following embodiments and features of the embodiments can be combined with each other. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0027] like Figure 1 and Figure 2 As shown in the figure, this invention discloses a cooling system and control method for a high-pressure turbine telemetry device of an aero-engine based on fuel-lubricating oil and air coupling. The system is designed around the core principles of "dual-medium synergistic cooling + active heat insulation + dynamic adaptation." Through active cooling via fuel-lubricating oil and air coupling, it achieves dual protection through "direct air cooling + fuel-lubricating oil temperature control of the substrate." Furthermore, it constructs an intelligent control algorithm based on a temperature rise model and a thermal balance model, employing a closed-loop control logic of "model calculation to set the benchmark, sensor feedback for dynamic adjustment, and dual-system linkage decision-making" to achieve stable, reliable, and adaptive temperature control of the telemetry device.

[0028] Specifically, the cooling system for a high-pressure turbine telemetry device of an aero-engine based on fuel-lubricating oil and air coupling designed in this invention includes an air supply and air cooling subsystem and a fuel-lubricating oil cooling subsystem.

[0029] The air supply and air cooling subsystem directly cools the telemetry device and provides active insulation for the main cooling air. It includes a double-layered sleeve installed inside the high-temperature exhaust support plate at the turbine's rear end. The inner tube of the double-layered sleeve forms a first airflow path for delivering the main cooling air, while the outer tube is fitted over the inner tube. The annular cavity between the two forms a second airflow path for delivering isolation cooling air. The second airflow path delivers cooling air to reduce the heating of the cold air in the first airflow path by the high-temperature gas, thus reducing its temperature rise along the path.

[0030] like Figure 1 The outlet end of the first airflow path is connected to three branches with different functions: The first one is a sealing branch, which is connected to the engine rear bearing cavity through the rear bearing sealing device, and is used to heat-insulate and seal the engine rear bearing cavity; The second branch is a heat insulation branch, which connects to the inner cone cavity behind the turbine through the interlayer cavity of the turbine rear end cover, and is used to isolate the high-temperature gas from the radiative heat transfer of the telemetry device. The third branch is a cooling branch, which connects to the gas collecting ring cavity of the telemetry device. Cooling gas enters the gas collecting ring cavity and then flows out, performing impact cooling on the electronic components of the telemetry device.

[0031] The fuel-oil cooling subsystem includes a fuel-oil radiator located outside the engine. Its oil-side inlet is connected to the oil outlet pipe of the engine rear bearing cavity, and its oil-side outlet is connected to the engine oil return pipe. The oil cooled by the fuel-oil radiator flows back to the engine rear bearing cavity to cool the journal of the turbine rear shaft, thereby indirectly reducing the temperature of the mounting base of the telemetry device.

[0032] In this invention, bench fuel is used to further cool the lubricating oil from the bearing cavity, thereby reducing the lubricating oil temperature and consequently lowering the temperature of the turbine rear journal in contact with the lubricating oil. This reduces heat conduction from the high-temperature substrate to the telemetry device along the heat transfer path. Furthermore, since the telemetry device is fixedly mounted on the stator structure adjacent to the journal, its mounting base can be thermally coupled to the journal. Cooling the journal indirectly reduces the temperature of the mounting base.

[0033] In one embodiment, the first airflow path, the second airflow path, and the fuel-side pipeline of the fuel-oil cooler are all equipped with flow regulating valves. For example, a first flow regulating valve is installed in the first airflow path, a second flow regulating valve is installed in the second airflow path, and a third flow regulating valve is installed in the fuel-side pipeline of the fuel-oil cooler. The flow rate of each flow path can be precisely adjusted according to the cooling requirements to meet the usage requirements of different engine operating conditions.

[0034] In one embodiment, a first temperature sensor is provided on the lubricating oil outlet pipe of the engine rear bearing cavity to monitor the temperature of the lubricating oil flowing out of the engine rear bearing cavity; a second temperature sensor is provided on the housing of the telemetry device or in its immediate vicinity to monitor the operating temperature of the telemetry device.

[0035] In one embodiment, the cooling branch is connected to multiple impact cooling holes on the telemetry device mounting base via an air collection ring cavity, allowing cooling air to form a uniform jet that impacts the heat-generating elements of the telemetry device. In a more detailed implementation, multiple cooling channels can be arranged circumferentially around the telemetry module and voltage regulator module of the telemetry device. The third cooling branch is connected to each cooling channel, allowing air from the cooling branch to form a jet that impacts and cools the electronic components of the telemetry module, improving local cooling efficiency.

[0036] In one embodiment, the flow path design and control method of the air supply and air cooling subsystem can determine the cooling air demand based on the actual engine operating conditions. The temperature rise ΔT of the cooling air along the first induced draft path is calculated using an established double-layered tube heat transfer model to ensure it does not exceed 40°C. This temperature rise is determined by the following formula: (1) Calculate the Reynolds number for each flow path: , , ; Wherein, m1, m2 and m3 are the air flow rates of the first air intake path, the second air intake path and the gap path between the outer pipe and the high-temperature exhaust support plate, respectively; The inner diameter of the inner tube. The outer diameter of the inner tube. The inner diameter of the outer tube; The outer diameter of the outer tube. The equivalent diameter μ of the inner wall of the high-temperature exhaust support plate is the gas dynamic viscosity.

[0037] (2) Calculate the convective heat transfer coefficients of the first air intake path, the second air intake path, and the high-temperature exhaust support plate gap flow path using the following formulas: ; ; ; in, The convective heat transfer coefficient of the first airflow path is... The convective heat transfer coefficient of the second airflow path. Pr is the convective heat transfer coefficient of the flow path between the high-temperature exhaust support plates. Where: Pr is the Prandtl number, and k is the thermal conductivity of air.

[0038] (3) Calculate the thermal resistance per unit tube length using the following formula: ; ; ; Among them, R 21 R is the thermal resistance per unit length between the first and second airflow paths. 32 R3 is the thermal resistance per unit length between the second airflow path and the gap flow path of the high-temperature exhaust support plate, and λ1, λ2, and λ3 are the thermal conductivity coefficients of the inner tube, outer tube, and high-temperature exhaust support plate wall materials, respectively. 3w The equivalent diameter of the outer wall of the high-temperature exhaust support plate.

[0039] (4) Calculate the overall heat transfer coefficient per unit length of the airflow from the high-temperature exhaust support plate to the first airflow path using the following formula: ; Among them, R 21 R 32 The expression for R3 already includes h1, h2, and h3. After substitution and simplification, the final complete expression for the overall heat transfer coefficient U can be obtained as follows: ; In the above formula, m3 and D 3n D 3w These are all engine design parameters. , The wall thickness of the inner and outer tubes can be compared with d. 1n d 2n Relatedly, the design and control of the air cooling flow path are achieved by adjusting m1, m2, and d. 1n d 2n accomplish.

[0040] (5) Based on the overall heat transfer coefficient, the high-temperature exhaust support plate wall temperature, the remote-measured cooling gas supply temperature of the test bench, the inner tube diameter, and the inner tube flow rate m1, a temperature rise model is established, with the following relationship: ; Where ΔT is the temperature rise along the friction path. The wall temperature of the high-temperature exhaust support plate. The test bench is used to remotely measure the cooling air supply temperature; L is the effective length of the inner tube in the high-temperature zone. This refers to the specific heat capacity of air at constant pressure.

[0041] As can be seen from the above formula, the airflow rate m1 of the first induced draft path directly affects the temperature rise ΔT along the path, and also influences... h1, R 21 This indirectly affects the overall heat transfer coefficient U, thus influencing the temperature rise along the path ΔT; the airflow rate m2 in the second air intake path affects... h2, R 21 and R 32 This indirectly affects the overall heat transfer coefficient U, thereby regulating the temperature rise ΔT along the path.

[0042] Preferably, before using the heat transfer model, the overall heat transfer coefficient is obtained by solving the flow-heat exchange coupling field in the gap between the inner tube, outer tube and high-temperature exhaust support plate based on a pre-calibrated correlation or in real time.

[0043] In one embodiment, the flow path design and control method of the fuel-lubricating oil cooling subsystem is as follows: (1) Establish a fuel-lubricating oil thermal balance model. The model relationship is as follows: ; in, For fuel mass flow rate, This refers to the mass flow rate of the lubricating oil. The specific heat capacity of lubricating oil at constant pressure. and These are the inlet and outlet temperatures of the lubricating oil, respectively. The specific heat capacity of fuel at constant pressure. and These are the inlet and outlet temperatures of the fuel, respectively. The heat transfer efficiency of the fuel-oil radiator.

[0044] In addition, to adapt to the changing operating conditions of the engine and ensure redundant cooling capacity, the actual fuel mass flow rate is 1.1 to 1.3 times the theoretical fuel mass flow rate, preferably 1.2 times, which means giving a margin of about 20%.

[0045] In one embodiment, the system is evaluated and its parameters optimized according to user requirements, based on the temperature of the peripheral cavity of the telemetry device (the bench telemetry cooling gas supply temperature T). in + Temperature rise along the bearing thread ΔT), measured value of bearing cavity lubricating oil temperature This achieves system-level coupling between upstream air preheating and downstream bearing cavity cooling requirements, and allows for graded and coordinated adjustment of the air supply path and oil supply path to ensure the base temperature T of the telemetry device. yc ≤85℃.

[0046] (1) When the temperature rise along the path of the cold air ΔT is greater than or equal to the target temperature rise of 40°C, it indicates that the cooling air is preheated to a high degree by the upstream high-temperature exhaust support plate, the inlet air temperature of the telemetry device is too high, and the air cooling efficiency is insufficient. At this time, it is recommended to increase the flow rate m1 of the supply air path to improve the overall cooling effect and enhance the direct cooling capacity.

[0047] (2) When the temperature rise along the cooling air path ΔT < the target temperature rise of 40℃, it indicates that the preheating degree of the cooling air is low and the cooling potential is sufficient. If at this time If the temperature exceeds 85℃, adjust the oil supply path to increase fuel flow, enhance lubricating oil cooling, and directly control the bearing cavity heat source temperature. When When the temperature is ≤85℃, it indicates that the cooling effect meets the requirements and the basic flow rates of the air and oil circuits remain unchanged.

[0048] Using the adjusted parameters as boundary conditions, a three-dimensional fluid-solid-thermal coupled simulation is employed to comprehensively evaluate the telemetry device. The predicted temperature T_device of the telemetry device is obtained through simulation. It must be ensured that T_device < the safety threshold (85°C). If this is not met, the process must return to step S1 or S2 to adjust the parameters and perform iterative optimization until all cooling targets are met.

[0049] like Figure 3As shown, this embodiment of the invention also provides a control method for the above-mentioned cooling system, the control method comprising the following steps: S1. Obtain the main cooling air supply temperature, high-temperature exhaust support plate wall temperature, inner pipe geometry, air mass flow rate and overall heat transfer coefficient, and calculate the friction temperature rise ΔT of the main cooling air from the inlet to the outlet based on the friction temperature rise model; when the friction temperature rise ΔT ≥ the temperature rise threshold (e.g., 40℃), increase the gas flow rate of the first and second induced draft paths. S2. Obtain the lubricating oil inlet temperature, lubricating oil outlet temperature, lubricating oil mass flow rate, fuel inlet and outlet temperatures, fuel specific heat capacity, lubricating oil specific heat capacity and radiator heat transfer efficiency, calculate the required theoretical fuel mass flow rate based on the heat balance relationship, and dynamically adjust the actual fuel mass flow rate according to the lubricating oil outlet temperature so that the lubricating oil outlet temperature does not exceed the set temperature (e.g., 85°C). S3. Monitor the operating temperature T_device of the telemetry device in real time; if the operating temperature T_device is greater than or equal to the set temperature, return to step S1 and / or step S2 to readjust the gas flow rate or fuel flow rate until the operating temperature T_device is less than the set temperature (e.g., 85°C).

[0050] The embodiments of the present invention achieve the following technical effects: 1. The dual-path coupled cooling architecture, which consists of "air direct cooling device body and lubricating oil cooling mounting base", can suppress temperature rise simultaneously from both ends of the heat source and heat transfer path, thus overcoming the bottleneck of insufficient cooling capacity of a single medium.

[0051] 2. By adopting a double-layer sleeve structure and a friction-based temperature rise calculation method, the main cooling airflow can effectively suppress heat absorption and temperature rise in a high-temperature environment, thus significantly improving cooling efficiency.

[0052] 3. By constructing a complete calculation model that covers air cooling temperature rise and fuel-lubricating oil thermal balance, the system design is transformed from experience-based vectorized analysis, thereby improving design accuracy and reliability.

[0053] 4. Temperature sensors and flow control valves are arranged in each flow path, and closed-loop regulation of cooling flow is realized based on real-time feedback. It can flexibly respond to changes in heat load under different steady-state / transient operating conditions of the engine and has good robustness.

[0054] 5. The system architecture designed in this invention is clear, the components are mature (such as sleeves, radiators, valves, and sensors), and it is easy to integrate and implement in engineering. Moreover, its concept of combining coupled cooling and dynamic control can also be extended to the thermal management design of other high-temperature rotating components.

[0055] Obviously, those skilled in the art should understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Various modifications and variations of the embodiments of the present invention are possible for those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A cooling system for a high-pressure turbine telemetry device of an aero-engine based on fuel-lubricating oil and air coupling, characterized in that, The cooling system includes: The air supply and air cooling subsystem is used to directly cool the telemetry device and provide active heat insulation for the main cooling air. It includes a double-layered sleeve installed inside the high-temperature exhaust support plate at the rear end of the turbine. The inner tube of the double-layered sleeve forms the first airflow path for conveying the main cooling air, and the outer tube is sleeved outside the inner tube. The annular cavity between the two forms the second airflow path for conveying the isolation cooling air. The outlet end of the first airflow path is connected to three branches with different functions: The first branch is a sealing branch, which connects to the rear bearing cavity of the engine and is used to heat-insulate and seal the rear bearing cavity of the engine. The second branch is a heat insulation branch, which connects to the inner cone cavity behind the turbine and is used to isolate the high-temperature gas from the radiative heat transfer of the telemetry device. The third branch is a cooling branch, which connects to the gas collection ring cavity of the telemetry device and is used to perform impact cooling on the electronic components of the telemetry device. The fuel-oil cooling subsystem includes a fuel-oil radiator located outside the engine. Its oil-side inlet is connected to the oil outlet pipe of the engine rear bearing cavity, and its oil-side outlet is connected to the engine oil return pipe. The oil cooled by the fuel-oil radiator flows back to the engine rear bearing cavity to cool the journal of the turbine rear shaft, thereby indirectly reducing the temperature of the mounting base of the telemetry device.

2. The cooling system for the high-pressure turbine telemetry device of an aero-engine according to claim 1, characterized in that, The first airflow path, the second airflow path, and the fuel side pipeline of the fuel-oil cooler are all equipped with flow regulating valves.

3. The cooling system for the high-pressure turbine telemetry device of an aero-engine according to claim 1, characterized in that, A first temperature sensor is provided on the lubricating oil outlet pipe of the engine rear bearing cavity to monitor the temperature of the lubricating oil flowing out of the engine rear bearing cavity; a second temperature sensor is provided on the housing of the telemetry device or in its immediate vicinity to monitor the operating temperature of the telemetry device.

4. The cooling system for the high-pressure turbine telemetry device of an aero-engine according to claim 1, characterized in that, The cooling branch is connected to multiple impact cooling holes on the mounting base of the telemetry device through the air collection ring cavity, so that the cooling air forms a uniform jet to impact the heating element of the telemetry device.

5. The cooling system for the high-pressure turbine telemetry device of an aero-engine according to claim 1, characterized in that, The temperature rise ΔT of the main cooling air along the path in the first airflow path is calculated using the following heat transfer model to evaluate the cooling efficiency: ； in, The wall temperature of the high-temperature exhaust support plate. The test bench is used to remotely measure the cooling air supply temperature; L is the effective length of the inner tube in the high-temperature zone. The specific heat capacity of air at constant pressure. The inner diameter of the inner tube. U is the air mass flow rate of the first air intake path, and U is the overall heat transfer coefficient.

6. The cooling system for the high-pressure turbine telemetry device of an aero-engine according to claim 5, characterized in that, Before using the heat transfer model, the overall heat transfer coefficient is obtained by solving the flow-heat exchange coupling field in the gap between the inner tube, outer tube and high-temperature exhaust support plate in real time, based on the pre-calibrated correlation.

7. The cooling system for the high-pressure turbine telemetry device of an aero-engine according to claim 1, characterized in that, The fuel mass flow rate through the fuel-oil radiator is calculated based on the following heat balance model to determine the fuel-side cooling requirement: ； in, For fuel mass flow rate, This refers to the mass flow rate of the lubricating oil. The specific heat capacity of lubricating oil at constant pressure. and These are the inlet and outlet temperatures of the lubricating oil, respectively. The specific heat capacity of fuel at constant pressure. and These are the inlet and outlet temperatures of the fuel, respectively. The heat transfer efficiency of the fuel-oil radiator.

8. A control method for controlling the cooling system according to any one of claims 1 to 7, characterized in that, include: Obtain the main cooling air supply temperature, high-temperature exhaust support plate wall temperature, inner pipe geometry, air mass flow rate, and overall heat transfer coefficient. Calculate the friction temperature rise ΔT of the main cooling air from inlet to outlet based on the friction temperature rise model. When the friction temperature rise ΔT ≥ the temperature rise threshold, increase the gas flow rate of the first and second induced draft paths. The system acquires the lubricating oil inlet temperature, lubricating oil outlet temperature, lubricating oil mass flow rate, fuel inlet and outlet temperatures, fuel specific heat capacity, lubricating oil specific heat capacity, and radiator heat transfer efficiency. Based on the heat balance relationship, it calculates the required theoretical fuel mass flow rate and dynamically adjusts the actual fuel mass flow rate according to the lubricating oil outlet temperature to ensure that the lubricating oil outlet temperature does not exceed the set temperature. Monitor the operating temperature T_device of the telemetry device in real time; if the operating temperature T_device is greater than or equal to the set temperature, return to step S1 and / or step S2 to readjust the gas flow rate or fuel flow rate until the operating temperature T_device is less than the set temperature.

9. The control method according to claim 8, characterized in that, The actual fuel mass flow rate is 1.1 to 1.3 times the theoretical fuel mass flow rate.

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