Air inlet heating test run emergency treatment method for self-suction mixing type aero-engine

Abstract

The invention belongs to the technical field of aero-engines, and particularly relates to an air inlet heating test run emergency treatment method for a self-suction mixing type aero-engine. The engine inlet total temperature is monitored in real time; the engine inlet total temperature is divided into a low-temperature section, a medium-temperature section and a high-temperature section according to the highest inlet total temperature capable of being borne by an engine; when an abnormal condition occurs in the test run process, executing a corresponding emergency operation process according to the type of the abnormal condition and the current temperature section; wherein the types of the abnormal conditions comprise non-treatment, proper reduction of the rotating speed of an engine, reduction of the rotating speed to slow running and direct parking; according to the emergency operation process, the sequence and amplitude of engine rotating speed adjustment and air inlet temperature adjustment are stipulated for different types and different temperature sections.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of aero-engines, and particularly relates to an emergency handling method for self-suction and mixing type aero-engine inlet temperature raising test running. BACKGROUND

[0002] A large number of whole machine tests are needed to support and verify the development process of an aero-engine, and the most commonly used whole machine test is normal temperature inlet whole machine ground test. In order to simulate the higher engine inlet total temperature under the condition of high altitude and high Mach number, whole machine inlet temperature raising test is needed. The current aero-engine inlet temperature raising test mainly adopts two ways of full hot gas supply and self-suction and mixing type. The self-suction and mixing type inlet temperature raising test is to increase a stabilizing box at the engine inlet, the stabilizing box has two inlets, the main inlet is atmospheric air inlet, the atmospheric air is sucked into the engine by the natural suction force of the engine, and the other inlet is a hot air inlet, which is generally pressure supplied. The atmospheric air and the hot air of the two inlets are mixed in the stabilizing box and then are sucked into the engine inlet after full mixing. In the self-suction and mixing type inlet temperature raising test, the hot air supply flow is generally adjusted by adjusting the opening degree of the hot air supply valve. Because the response of the hot air supply adjusting valve is slow, and there is a large volume of mixing box, the response of the engine inlet temperature adjustment in the actual operation process is slow, which must be considered in the emergency handling.

[0003] The whole engine internal flow path temperature is at a high level due to the high engine inlet temperature in the inlet temperature raising test, especially when the temperature is high, the high and low pressure turbines and the rear fulcrum bearing and other components are close to the design limit temperature. If the post-processing is not careful after the abnormal situation occurs, the hot end components are easy to be seriously ablated or systematically damaged, which is extremely harmful to the engine. After consulting relevant public documents, no related information about the emergency handling of the temperature raising test is found. In the actual engineering test, in addition to the emergency shutdown, the principle of first reducing the engine inlet total temperature and then reducing the engine speed is generally adopted for the emergency handling in the temperature raising test.

[0004] From the public query information, it can be seen that some test benches adopt the self-suction and mixing type inlet temperature raising, but there is no related report about the emergency handling in the inlet temperature raising process. Based on the principle of first reducing the engine inlet total temperature and then reducing the engine speed commonly used in engineering practice, there are still some drawbacks:

[0005] 1) A systematic emergency handling method based on the self-suction and mixing type inlet temperature raising mode has not been established;

[0006] 2) In the temperature raising test of this mode, the engine needs to be urgently reduced in speed, and the first temperature reduction and then speed reduction will cause the engine to be in abnormal working condition for a long time, which causes damage to the engine. SUMMARY

[0007] To solve the above problems, a self-suction mixing type aero-engine inlet temperature test emergency handling method, characterized in that, comprising the following steps:

[0008] Real-time monitoring of engine inlet total temperature;

[0009] According to the highest inlet total temperature that the engine can withstand, the engine inlet total temperature is divided into low temperature section, medium temperature section and high temperature section;

[0010] When abnormal conditions occur during the test, according to the type of abnormal conditions and the current temperature section, the corresponding emergency operation process is executed;

[0011] Among them, the abnormal condition type includes: no treatment, appropriately reducing engine speed, reducing speed to slow speed, and directly stopping;

[0012] The emergency operation process specifies the sequence and amplitude of engine speed regulation and inlet temperature regulation for different types and different temperature sections.

[0013] Preferably, the temperature section is divided as follows:

[0014] The low temperature section is between the ambient temperature and (normal temperature 25℃+(maximum temperature that can be tolerated-normal temperature 25℃)*20%);

[0015] The medium temperature section is between (normal temperature 25℃+(maximum temperature that can be tolerated-normal temperature 25℃)*20%) and (normal temperature 25℃+(maximum temperature that can be tolerated-normal temperature 25℃)*80%);

[0016] The high temperature section is between (normal temperature 25℃+(maximum temperature that can be tolerated-normal temperature 25℃)*80%) and the maximum temperature that can be tolerated.

[0017] Preferably, if the current is in the low temperature section, the engine speed is reduced and the inlet temperature is adjusted to the preset value at the same time;

[0018] If the current is in the medium temperature section, first adjust the inlet temperature according to the preset gradient, then reduce the engine speed by 1%~3%; repeat this process until the low temperature section is entered and handled according to the low temperature section measures;

[0019] If the current is in the high temperature section, first adjust the inlet temperature according to the preset gradient, then adjust the engine speed according to the preset gradient; repeat this process until the medium temperature section is entered and handled according to the medium temperature section measures.

[0020] Preferably, when the abnormal condition type is to reduce the speed to slow speed, the emergency operation process includes:

[0021] If the current is in the low temperature section, the emergency cut-off heating supply should be gradually reduced to slow speed;

[0022] If the current temperature range is medium, immediately cut off the heating gas supply and start slowly reducing the speed by 3% to 5%, then pause for 3 to 5 seconds; if the intake air temperature decreases normally, repeat the speed reduction operation until the temperature range is reached, then directly reduce the speed to slow.

[0023] If the current temperature is in the high-temperature range, the heating gas supply should be cut off immediately. Once the inlet temperature drops to the medium-temperature range, the operation should be carried out according to the medium-temperature range.

[0024] Preferably, when the abnormal situation type is direct shutdown, the emergency operation procedure is as follows: directly execute the shutdown operation and simultaneously cut off the heating gas supply.

[0025] Preferably, all emergency operations follow a priority principle: direct shutdown has the highest priority, followed by slowing down the engine, then appropriately reducing the engine speed, and the lowest priority is no action; when a high-priority operation is triggered during a low-priority emergency operation, the high-priority operation is executed.

[0026] Preferably, during any emergency operation, the exhaust temperature after the engine turbine is monitored in real time, and when the temperature exceeds the engine's tolerance limit, the engine is stopped and the heating gas supply is cut off.

[0027] An emergency response system for implementing the emergency response method for inlet air heating during the test of the self-priming mixed-type aero-engine includes:

[0028] The temperature monitoring module is used to monitor the engine inlet total temperature in real time.

[0029] Valve control module, used for remote control of the intake and exhaust regulating valves of heating equipment;

[0030] The processing logic module has pre-stored emergency operation procedures based on temperature range division and abnormal situation types;

[0031] The execution module is used to perform corresponding engine speed regulation and valve control operations according to the instructions of the processing logic module.

[0032] Preferably, the valve control module is configured to automatically close the heating equipment gas supply valve and fully open the exhaust valve when an emergency shut-off heating gas supply command is received.

[0033] This invention comprehensively considers engine emergency situations and intake air heating total temperature, and establishes a systematic emergency handling method applicable to self-priming intake heating test runs. Combined with integrated hardware and software control, a heating test run emergency handling system has been established.

[0034] By intelligently classifying and categorizing temperature ranges, emergency handling measures are provided during emergency intake air heating test runs. Considering the engine's temperature load tolerance in the medium and low temperature ranges, this reduces the need for the engine to be cooled down before its RPM is reduced. While ensuring engine safety, this effectively reduces the duration of abnormal conditions and minimizes engine damage. Simultaneously, an emergency heating supply cutoff setting is established, enabling relatively rapid heating cutoff operations and reducing potential engine damage. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the intake heating test of a self-aspirating mixed-flow aero-engine. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are only some, not all, of the embodiments of this application. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application. The embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0037] This invention is applicable to inlet air heating tests of aero engines, such as... Figure 1 As shown in the diagram, 1 is the hot air supply pipeline, 2 is the intake regulating valve, 3 is the exhaust pipeline, 4 is the exhaust regulating valve, 5 is the mixer, 6 is the pressure stabilizing box, 7 is the engine intake duct, 8 is the engine, and 9 is ambient air. During the intake air heating test, the hot air supply pipeline 1 supplies hot air at a certain pressure to the test chamber. By opening the intake regulating valve 2 and appropriately adjusting the exhaust regulating valve 4, hot air is supplied to the mixer 5. At the same time, the engine 8 generates suction force when it is running, drawing ambient air from the engine inlet to the engine inlet. At the mixer 5, the ambient air and the hot air from the hot air supply pipeline are mixed. After passing through the pressure stabilizing box 6, they are fully mixed and flow to the engine intake duct 7, and are finally drawn into the engine.

[0038] In self-priming mixed-intake heating systems, because the hot air supply line is at a pressure higher than atmospheric pressure, the supply of hot air remains constant as long as the intake regulating valve opening remains unchanged, regardless of engine speed. However, the intake flow rate of ambient temperature air at the engine inlet varies with engine speed. Higher engine speeds require a larger airflow, resulting in more ambient temperature air being drawn in. With a constant hot air flow rate, this leads to a higher proportion of ambient temperature air at the engine inlet and a lower overall engine inlet temperature. Conversely, lower engine speeds require a smaller airflow, resulting in less ambient temperature air being drawn in. With a constant hot air flow rate, this leads to a lower proportion of ambient temperature air at the engine inlet and a higher overall engine inlet temperature. Furthermore, these heating systems typically have slow intake regulating valve response times. The valve diameter varies depending on the engine airflow rate, the diameter of the hot air supply line, and the valve's overall diameter. Generally, the response time for a larger diameter intake regulating valve to fully open or close is around 40 seconds, and can even reach one minute.

[0039] Therefore, in actual engineering operations, self-priming mixed heating test runs generally follow the principle of increasing speed before heating during the lifting stroke and decreasing temperature before decreasing speed during the lowering stroke. This is to prevent the engine inlet total temperature from exceeding the limit due to untimely temperature response, which in turn leads to excessive exhaust temperature after the engine turbine or other damage.

[0040] 2. Emergency handling methods for aircraft engine ground test at normal temperature

[0041] When abnormal situations such as parameter exceeding limits, engine malfunction, or test failure occur during routine testing of a naturally aspirated engine at normal temperature, the emergency handling measures mainly fall into the following categories:

[0042] 1) No action is required. Although an anomaly has occurred, it does not affect the safety or achievement of the objectives of this engine test run, and no action is necessary at this time.

[0043] 2) Reduce engine speed appropriately. When certain parameters exceed or are about to exceed limits during the test run, it is necessary to reduce the engine speed, and the parameters will also decrease accordingly, allowing the remaining test run tasks to be completed without exceeding the limits.

[0044] 3) Reduce RPM to idle. If certain situations occur during the test run and the engine is no longer suitable for continued operation at a high speed, first reduce the RPM to idle to troubleshoot. If the problem can be resolved by certain measures at idle, the test run can continue; or reduce the RPM to idle and run the engine for 1-5 minutes to cool it down before stopping the engine to troubleshoot.

[0045] 4) Stop the engine immediately. In some cases, continuing to run the engine can cause very serious damage to the engine, equipment, or personnel, so it is necessary to stop the engine immediately.

[0046] 3. Emergency handling methods during intake air heating test run

[0047] This invention establishes a systematic emergency handling method applicable to self-priming intake heating test runs. It also realizes automatic handling, manual remote handling, or visual prompts for handling operations based on different situations through remote valve control, PLC control, and software programming, reducing the pressure on on-site operators and minimizing damage to the engine during emergency handling.

[0048] Hardware preparation: Install an inlet total temperature tester at the engine inlet and transmit the test results to this system; configure the heating control valves for heating air supply and exhaust to be remotely controlled by this system; the system software communicates with the engine controller and obtains relevant signals for engine alarms and emergency handling.

[0049] System emergency handling methods:

[0050] 1) An emergency shut-off function for heating gas supply is set on the control panel. This function has two modes: manual triggering by the operator and automatic triggering upon receiving a communication signal. When the emergency shut-off function for heating gas supply is triggered, the gas supply valve of the heating equipment is shut off immediately, and the exhaust valve is fully opened immediately.

[0051] When the engine malfunctions, it will automatically cut off fuel, causing a rapid decrease in engine speed. The alarm signal for this situation should be automatically interlocked with the test bench's emergency air supply cutoff function. Once the engine triggers the fuel cutoff and speed reduction scenario, the test bench's emergency heating air supply cutoff function will also be activated, thus achieving rapid start-up of the heating air supply cutoff.

[0052] 2) Through software programming, the engine inlet temperature is divided into three temperature ranges: low, medium, and high. Different operations or operation prompts are given for different temperature ranges.

[0053] Temperature range division criteria: Refer to the engine's maximum inlet total temperature that it can withstand. Note that this refers to the engine's own design-controlled maximum steady-state inlet total temperature, not the maximum inlet total temperature planned for this test run. Division method: Low temperature range = ambient air temperature ~ (25℃ + (maximum tolerable temperature - 25℃) * 20%); Medium temperature range = (25℃ + (maximum tolerable temperature - 25℃) * 20%) ~ (25℃ + (maximum tolerable temperature - 25℃) * 80%); High temperature range = (25℃ + (maximum tolerable temperature - 25℃) * 80%) ~ maximum tolerable temperature.

[0054] Emergency response principles:

[0055] a) In the emergency handling of engine malfunctions, if no action is taken during the heating test run and it will not cause damage to the engine, equipment, or personnel, then no action will be taken during the heating test run.

[0056] b) In emergency situations involving engine malfunctions requiring immediate shutdown, the emergency procedure during warm-up testing is as follows: immediately shut down the engine and simultaneously cut off the heating. During shutdown, the engine may briefly overheat due to an increase in the total inlet temperature.

[0057] c) In emergency situations involving engine malfunctions where it is necessary to "appropriately reduce engine speed," the emergency handling measures during warm-up testing are as follows:

[0058] ① Low temperature range: Simultaneously reduce engine speed and lower intake air temperature;

[0059] ② Medium temperature range: Adjust the intake air temperature appropriately and reduce the engine speed slightly. Generally, the speed should be reduced by 1% to 3% in a single adjustment. If the speed and temperature still need to be reduced after they stabilize, repeat this operation, adjust the intake air temperature appropriately and reduce the engine speed slightly again. Continue this operation until you enter the low temperature range, then handle it according to the low temperature range measures.

[0060] ③ High temperature range: First, appropriately lower the intake air temperature. After the intake air temperature decreases and stabilizes, appropriately lower the engine speed. If the engine speed still needs to be reduced after it stabilizes, repeat this operation: first, appropriately lower the intake air temperature. After the intake air temperature decreases and stabilizes, appropriately lower the engine speed. Continue this operation until you enter the medium temperature range, then handle it according to the measures for the medium temperature range.

[0061] d) Emergency handling measures during warm-up testing for situations requiring "reducing engine speed to idle" in emergency situations involving engine malfunctions:

[0062] ① Low temperature section: Emergency shutdown of heating, while gradually reducing the engine speed to low;

[0063] ②Medium temperature range: Emergency shut-off heating, and at the same time start to slowly reduce the speed by 3%~5%, then hold the speed for 3s~5s. If the intake air temperature drops normally, repeat the slow reduction of the speed by 3%~5% and hold the speed for 3s~5s until the total temperature of the engine inlet drops to the low temperature range, then directly reduce the speed to slow down.

[0064] ③High temperature section: Emergency shut-off heating, and after the inlet temperature drops to the medium temperature section, start operating according to the medium temperature section.

[0065] e) The priority of emergency operations during intake heating is "directly stop" > "reduce engine speed to slow" > "appropriately reduce engine speed" > "do nothing". That is, when a low-priority emergency operation is performed, if a high-priority emergency operation is triggered, the high-priority emergency operation will be handled accordingly.

[0066] f) During all emergency operations, the exhaust temperature after the engine turbine should be monitored at all times. If the exhaust temperature exceeds the engine's tolerance limit, the engine should be stopped immediately and the heating should be cut off in an emergency.

[0067] This invention comprehensively considers engine emergency situations and intake air heating total temperature, and establishes a systematic emergency handling method applicable to self-priming intake heating test runs. Combined with integrated hardware and software control, a heating test run emergency handling system has been established.

[0068] By intelligently classifying and categorizing temperature ranges, emergency handling measures are provided during emergency intake air heating test runs. Considering the engine's temperature load tolerance in the medium and low temperature ranges, this reduces the need for the engine to be cooled down before its RPM is reduced. While ensuring engine safety, this effectively reduces the duration of abnormal conditions and minimizes engine damage. Simultaneously, an emergency heating supply cutoff setting is established, enabling relatively rapid heating cutoff operations and reducing potential engine damage.

[0069] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A self-suction mixing type aero-engine intake warming test run emergency handling method, characterized in that, The method comprises the following steps: Real-time monitoring of engine inlet total temperature; According to the highest engine inlet total temperature that the engine can withstand, the engine inlet total temperature is divided into low temperature section, medium temperature section and high temperature section; When an abnormal situation occurs during the test run, the corresponding emergency operation process is executed according to the type of the abnormal situation and the current temperature section; The abnormal situation type includes: no treatment, appropriately reducing the engine speed, reducing the speed to idle speed, and directly stopping the engine; The emergency operation process specifies the sequence and amplitude of engine speed adjustment and inlet temperature adjustment for different types and different temperature sections.

2. The self-suction mixing type aircraft engine inlet temperature test run emergency handling method according to claim 1, wherein the temperature section is divided in the following manner: The low temperature section is between the ambient atmospheric temperature and (normal temperature 25℃ + (the highest temperature that can be withstood - normal temperature 25℃) * 20%); The medium temperature section is between (normal temperature 25℃ + (the highest temperature that can be withstood - normal temperature 25℃) * 20%) and (normal temperature 25℃ + (the highest temperature that can be withstood - normal temperature 25℃) * 80%); The high temperature section is between (normal temperature 25℃ + (the highest temperature that can be withstood - normal temperature 25℃) * 80%) and the highest temperature that can be withstood.

3. The self-suction mixing type aircraft engine inlet temperature test run emergency handling method according to claim 1, wherein if the current temperature section is the low temperature section, the engine speed is reduced and the inlet temperature is adjusted to a preset value at the same time; If the current temperature section is the medium temperature section, the inlet temperature is first adjusted at a preset gradient, and then the engine speed is reduced by 1% to 3%; this process is repeated until the low temperature section is entered and the low temperature section measures are taken; If the current temperature section is the high temperature section, the inlet temperature is first adjusted at a preset gradient, and then the engine speed is adjusted at a preset gradient; this process is repeated until the medium temperature section is entered and the medium temperature section measures are taken.

4. The self-suction mixing type aircraft engine inlet temperature test run emergency handling method according to claim 1, wherein when the abnormal situation type is reducing the speed to idle speed, the emergency operation process includes: If the current temperature section is the low temperature section, the emergency cut-off of the heating gas supply is performed, and the speed is gradually reduced to idle speed at the same time; If the current temperature section is the medium temperature section, the emergency cut-off of the heating gas supply is performed, and the speed is slowly reduced by 3% to 5% at the same time, and then it is stopped for 3s to 5s; if the inlet temperature does not show abnormal downward trend, the speed reduction operation is repeated until the low temperature section is entered and the speed is directly reduced to idle speed; If the current temperature section is the high temperature section, the emergency cut-off of the heating gas supply is performed, and the medium temperature section operation is performed after the inlet temperature is reduced to the medium temperature section. When the abnormal situation type is direct stopping, the emergency operation process is to directly perform the stopping operation and simultaneously perform the emergency cut-off of the heating gas supply. All emergency operations follow the priority principle: the direct stopping has the highest priority, the reducing the speed to idle speed has the second highest priority, the appropriately reducing the engine speed has the third highest priority, and the no treatment has the lowest priority; when a high-priority operation is triggered during a low-priority operation, the high-priority operation is executed. During the execution of any emergency operation, the engine turbine rear exhaust temperature is monitored in real time, and when the temperature exceeds the engine's limit value, the stopping operation and the cut-off of the heating gas supply are performed.

5. The self-priming, hybrid, aeroengine inlet air warming test run emergency handling method of claim 1, wherein, The method comprises:

6. The self-priming, hybrid, aeroengine inlet air warming test run emergency handling method of claim 1, wherein, ​ 7. The self-priming, hybrid, aeroengine inlet air warming test run emergency handling method of claim 1, wherein, ​ 8. An emergency handling system for implementing the emergency handling method of any one of claims 1-7, characterized in that, ​ A temperature monitoring module is configured to monitor the engine inlet total temperature in real time. A valve control module is configured to remotely control the air intake regulating valve and the air exhaust regulating valve of the heating device. A processing logic module pre-stores emergency operation procedures based on temperature segment division and abnormal situation types. An execution module is configured to execute corresponding engine speed adjustment and valve control operations according to the instructions of the processing logic module.

9. The emergency handling system of the emergency handling method of self-priming mixed- flow aeroengine intake warming run-in test according to claim 8, characterized in that, The valve control module is configured to automatically execute the operation of closing the air supply valve of the heating device and fully opening the air exhaust valve when receiving an emergency shutdown heating air supply instruction.

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