Method for in situ elimination of a failure of a turbojet engine to spool up

Abstract

The present application relates to the field of aero-engine maintenance process, and particularly relates to a method for eliminating the failure of aero-engine afterburning connection in situ, which can be used on the airplane or the test bench, and the method comprises the following steps: a. When the failure of aero-engine afterburning connection occurs, according to the test data or the flight parameter data, it is observed whether the ionization current value of the right flame ion sensor of the afterburning state is obviously smaller than that in the normal state of the engine; b. The V-shaped opening closing amount is determined; c. The V-shaped opening of the two radial stabilizers facing the flame ion sensor is calibrated by using a calibration fixture, and the calibration amount is determined according to the amount determined in step b; d. The complete tooling is checked, and it is checked that there is no redundant material in the engine; e. The engine is restarted, and it is observed whether the failure is eliminated, and if not, steps a to d are repeated. The present application is particularly suitable for eliminating and maintaining the failure of aero-engine afterburning connection.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of aero-engine maintenance process, and particularly relates to a method for eliminating a failure of a turbojet engine in a reheat state. BACKGROUND

[0002] The turbojet engine has a unique phenomenon that the ionization current value of the right flame ion sensor in the reheat state is too small. The reheat state refers to a state that the turbojet engine further rapidly increases the output power on the basis of normal operation to obtain stronger propulsion. The too small ionization current value of the engine will cause the digital regulator to mistakenly think that the reheat is not connected, but in fact the reheat is connected, and further causes the subsequent minimum reheat electromagnetic valve to be unable to be removed, so that the nozzle is always kept in the small reheat state, thereby causing the reheat failure. The above reheat failure can cause the take-off to be interrupted, the plane to fail to take off and to rush out of the runway, or the air maneuvering and fighting to fail, and the like, which are serious hazards. SUMMARY

[0003] The present application aims to provide a method for eliminating the reheat failure of the turbojet engine in the reheat state on the plane or the test bench.

[0004] The technical scheme adopted by the present application to solve the technical problem is as follows: the method for eliminating the reheat failure of the turbojet engine in the reheat state comprises the following steps: a. when the turbojet engine in the reheat state has a failure, according to the test data or the flight parameter data, it is observed whether the ionization current value of the right flame ion sensor in the reheat state is obviously smaller than that in the normal state of the engine, if yes, the following step b is executed: b. the ionization current value of the right flame ion sensor is read, the actual value is subtracted from the standard value to obtain a small difference value Δ, according to the relationship that every 10 uA difference value Δ corresponds to a 2 mm width of the V-shaped opening of the radial stabilizer, the V-shaped opening of the radial stabilizer is determined; c. the engine is stopped, and then when the internal temperature drops to below 40 DEG C, the reheat combustion chamber in the engine is measured from the tail nozzle of the engine, the V-shaped opening of the radial stabilizer directly opposite to the flame ion sensor is calibrated by using a calibration fixture, and the calibration amount is the amount determined in step b; d. after the calibration is completed, it is checked that the tooling is complete and that there is no extra material in the engine; e. the engine is restarted, and it is observed whether the failure is eliminated, if not, steps a to d are repeated.

[0005] Further, the engine is stopped for at least 60 minutes.

[0006] The beneficial effects of this invention are as follows: Based on the linear relationship between the width of the radial stabilizer's V-shaped opening and the ionization current value, this invention constructs a simple and reliable processing scheme. In actual processing, by adjusting the width of the radial stabilizer's V-shaped opening through the constructed linear relationship, the afterburner engagement failure can be eliminated. The entire maintenance process does not require relocating the engine, greatly improving maintenance efficiency and reducing maintenance labor intensity. This invention is particularly suitable for troubleshooting and repairing afterburner engagement failures in aero-engines. Detailed Implementation

[0007] The method for troubleshooting afterburner connection failure in an aero-engine in situ includes the following steps: a) When the afterburner connection failure occurs, observe whether the ionization current value of the right-side flame ionization sensor is significantly smaller than that under normal engine conditions, based on test run or flight parameter data. If so, continue with the following steps: b) Read the ionization current value of the right-side flame ionization sensor, subtract the actual value from the standard value to obtain the difference Δ. Determine the reduction amount of the V-shaped opening according to the relationship that every 10uA difference Δ corresponds to a 2mm reduction in the width of the radial stabilizer V-shaped opening; c) Shut down the engine, and then measure the temperature drop of the internal temperature to below 40°C. Enter the afterburner combustion chamber from the engine exhaust nozzle and use a calibration fixture to calibrate the two radial stabilizer V-shaped openings directly opposite the flame ionization sensor. The calibration amount is the amount determined in step b; d) After calibration, check that the tooling is complete and that there are no foreign objects inside the engine; e) Restart the engine and observe whether the fault is eliminated. If not, repeat steps a to d.

[0008] Through bench testing and finite element numerical simulation analysis, it was proven that the mechanism of the afterburner failure is that when the engine intake air volume increases, the gas flow velocity through the afterburner stabilizer increases, causing the sensor's sensing part to not overlap with the high-temperature zone of the afterburner flame. The sensor cannot detect the temperature of the high-temperature zone, resulting in a lower ionization current value and thus the afterburner failure. By calibrating the V-shaped openings of the two radial stabilizers directly opposite the sensor, the ionization current value can be effectively increased, eliminating the aforementioned fault. In actual operation, it is preferable to stop the engine for at least 60 minutes and wait for the temperature to drop below 40°C. The operator then crawls into the engine from the exhaust nozzle, moves to the afterburner, and uses a special calibration fixture to calibrate the V-shaped openings of the two radial stabilizers directly opposite the sensor.

[0009] Reducing the width of the two radial stabilizer V-shaped openings directly opposite the right-side flame ionization sensor significantly increases the ionization current value of the right-side flame ionization sensor, and the increase is approximately linearly positively correlated with the reduction in opening width. For every 2mm reduction in the V-shaped opening of the radial stabilizer, the ionization current value of the right-side flame ionization sensor increases by approximately 10uA. However, the reduction should not exceed 10mm, otherwise it will significantly affect the aerodynamic performance and combustion stability after the engine stabilizer. Specific experimental data are as follows:

[0010]

[0011] The above experiments show that when the V-shaped opening adjustment is small, the corresponding ionization current values ​​are all increased accordingly, thereby eliminating the misjudgment of "power not connected" caused by the digital regulator when the engine ionization current value is too small.

Claims

1. A method for troubleshooting afterburner engagement failure in an aircraft engine in situ, characterized in that, Includes the following steps: a. When an aircraft engine experiences an afterburner failure, observe whether the ionization current value of the flame ionization sensor on the right side of the engine is significantly lower than that under normal engine conditions, based on test or flight parameter data. If so, continue with the following steps: b. Read the ionization current value of the flame ionization sensor on the right, subtract the actual value from the standard value to obtain the deviation Δ, and determine the reduction amount of the V-shaped opening according to the relationship that every 10uA difference Δ corresponds to a 2mm reduction in the width of the radial stabilizer V-shaped opening; c. Stop the engine and then measure the temperature inside the engine until it drops below 40°C. Enter the afterburner from the engine exhaust nozzle and use a calibration fixture to calibrate the two radial stabilizer V-shaped openings facing the flame ionization sensor. The calibration amount is determined in step b. d. After calibration, check that the tooling is complete and that there are no extraneous objects inside the engine; e. Restart the engine and observe whether the fault is resolved. If not, repeat steps a to d.

2. The method for in-situ troubleshooting of afterburner engagement failure in aero-engines as described in claim 1, characterized in that: The engine should be shut down for at least 60 minutes.

Images