CN-121782036-B - Method and system for protecting low-pressure rotor broken shaft of turboshaft engine

CN121782036BCN 121782036 BCN121782036 BCN 121782036BCN-121782036-B

Abstract

The application discloses a method and a system for protecting a low-pressure rotor of a turboshaft engine from shaft breakage, and belongs to the technical field of aeroengines, wherein the method comprises the steps of obtaining engine operation data, wherein the engine operation data comprise a low-pressure rotor rotating speed, a high-pressure rotor rotating speed, an inlet pressure and fuel flow data supplied to the engine; the application carries out the low-pressure rotor shaft breakage judgment operation based on the engine operation data, and carries out the breakage protection operation after judging the low-pressure rotor shaft breakage, and carries out the breakage judgment of the low-pressure rotor shaft through the parameters of the low-pressure rotor rotation speed change rate, the fuel feedback, the inlet pressure and the like, the real-time detection of the broken shaft of the low-voltage rotor shaft can be realized, the detection efficiency is ensured, the broken shaft is prevented from causing larger damage to the engine, and the operation safety of the engine is effectively ensured.

Inventors

LI FENG
SONG YINYU
SU JINPING
YAN PENGCHENG
SU ZHIMIN
CHEN ZHIXIONG

Assignees

中国航发湖南动力机械研究所

Dates

Publication Date: 20260508
Application Date: 20260304

Claims (10)

1. A protection method for broken shaft of low-pressure rotor of turboshaft engine is characterized by comprising the following steps: Acquiring engine operation data, wherein the engine operation data comprises low-pressure rotor rotating speed, high-pressure rotor rotating speed, inlet pressure and fuel flow data supplied to an engine, and the inlet pressure is combustion chamber inlet pressure; performing a low-voltage rotor shaft breakage determination operation based on engine operation data, and performing a breakage protection operation after determining that the low-voltage rotor shaft is broken, the breakage determination operation including a third determination operation including: When the rotating speed of the high-pressure rotor is larger than the rotating speed of the slow vehicle and the rotating speed reduction rate of the low-pressure rotor exceeds the set speed, calculating to obtain a predicted value of inlet pressure based on fuel flow data supplied to the engine in a third set time of the rotating speed reduction of the low-pressure rotor; And calculating a judging threshold value based on the estimated value of the inlet pressure and the measured value of the inlet pressure, and judging that the low-pressure rotor shaft is broken when the judging threshold value is larger than a set threshold value.
2. The method of claim 1, wherein calculating an estimated value of the inlet pressure based on data of the fuel flow supplied to the engine comprises: Calculating the fuel flow rate of change supplied to the engine within a fourth set time, and calculating an estimated value of the inlet pressure based on the fuel flow rate of change; the ratio of the difference between the predicted value of the inlet pressure and the measured value of the inlet pressure and the maximum value of the measured value of the inlet pressure in the third set time is taken as a judging threshold value.
3. The method of claim 1, wherein the shaft breakage protection operation comprises a shutdown protection.
4. The method of claim 1, wherein the shaft breakage determination operation further comprises a first determination operation, the first determination operation comprising: And when the rotating speed of the high-pressure rotor is larger than the rotating speed of the slow car and the rotating speed of the low-pressure rotor is smaller than the first set rotating speed and the first set time is continued, judging that the low-pressure rotor shaft is broken.
5. The method for protecting a low-pressure rotor of a turboshaft engine according to claim 4, wherein the first set rotational speed is 30% of the rated rotational speed of the low-pressure rotor.
6. The method for protecting a low-pressure rotor of a turboshaft engine according to claim 4, wherein the protecting method is performed based on an electronic controller, and the first set time is equal to an operation period of the electronic controller.
7. The method of claim 4, wherein the shaft breakage determination operation further comprises a second determination operation, the second determination operation comprising: And in the starting process, in a second set time before the rotating speed of the high-pressure rotor is increased to the rotating speed of the slow car, when the rotating speed signal of the low-pressure rotor fails or the rotating speed of the low-pressure rotor is smaller than the second set rotating speed, judging that the shaft of the low-pressure rotor is broken.
8. The method for protecting a low-pressure rotor of a turboshaft engine according to claim 7, wherein the first set time is equal to the second set time, and the first set rotational speed is equal to the second set rotational speed.
9. A turboshaft engine low pressure rotor shaft break protection system comprising: an acquisition module configured to acquire engine operating data including a low pressure rotor speed, a high pressure rotor speed, an inlet pressure, and fuel flow data supplied to the engine; a determination execution model configured to execute a low-pressure rotor shaft breakage determination job based on engine operation data, and to execute a breakage protection operation after determining that the low-pressure rotor shaft is broken, the breakage determination job including a third determination job including: When the rotating speed of the high-pressure rotor is larger than the rotating speed of the slow vehicle and the rotating speed reduction rate of the low-pressure rotor exceeds the set speed, calculating to obtain a predicted value of inlet pressure based on fuel flow data supplied to the engine in a third set time of the rotating speed reduction of the low-pressure rotor; And calculating a judging threshold value based on the estimated value of the inlet pressure and the measured value of the inlet pressure, and judging that the low-pressure rotor shaft is broken when the judging threshold value is larger than a set threshold value.
10. The turboshaft engine low pressure rotor shaft break protection system of claim 9 wherein calculating an estimated value of inlet pressure based on fuel flow data supplied to the engine comprises: Calculating the fuel flow rate of change supplied to the engine within a fourth set time, and calculating an estimated value of the inlet pressure based on the fuel flow rate of change; the ratio of the difference between the predicted value of the inlet pressure and the measured value of the inlet pressure and the maximum value of the measured value of the inlet pressure in the third set time is taken as a judging threshold value.

Description

Method and system for protecting low-pressure rotor broken shaft of turboshaft engine Technical Field The application belongs to the technical field of aeroengines, and particularly relates to a method and a system for protecting a low-pressure rotor broken shaft of a turboshaft engine. Background As a key component for connecting a turbine and a compressor, the low-pressure rotor shaft of the aeroengine is easy to break due to fatigue, corrosion, material defects, manufacturing tolerances, bearing faults, insufficient lubrication and the like. After the shaft breaks, the mechanical connection between the turbine and the compressor is interrupted, the engine parameters change rapidly, the engine is easy to damage, and the operation safety is threatened, so that a low-pressure rotor shaft fault detection method is required to be set. The existing turbofan engine low-pressure rotor shaft fracture fault detection technology is relatively perfect, for example, referring to fig. 1 (in the figure, feature 1 is the acceleration rate of the low-pressure rotor rotation speed and the rotation speed conversion acceleration rate under different environmental pressures, feature 2 is the slip feature of the high-low pressure conversion rotation speed, T 0 is the summation starting time, and deltat is the summation time period), generally, an online detection method is constructed based on high-pressure and low-pressure physical rotation speeds measured on an airborne basis, parameters of normal acceleration and deceleration, surge and shaft breakage processes are distinguished through rotation speed change rate and slip relation, and fault detection is realized by combining working condition simulation identification and setting decision logic and threshold values. The method relies on a nonlinear performance model of the transitional turbofan engine based on component characteristics, is suitable for the turbofan engine with the large bypass ratio of double-shaft split arrangement, is only aimed at the broken shaft detection of the turbofan engine, is used for protecting the low-pressure rotor shaft of the turboshaft engine, is dependent on an over-rotation protection module of a control system, and realizes over-rotation protection through a rotating speed threshold, but cannot realize real-time identification in the flight state process, has low fault identification accuracy, and is difficult to meet the fault detection requirement of the low-pressure rotor shaft of the turboshaft engine. Disclosure of Invention In order to solve the problems, the application provides a method and a system for protecting a low-pressure rotor of a turboshaft engine from shaft breakage, which are used for solving the problems in the prior art. A protection method for broken shaft of low-pressure rotor of turboshaft engine includes: acquiring engine operating data including low pressure rotor speed, high pressure rotor speed, inlet pressure and fuel flow data supplied to the engine; performing a low-voltage rotor shaft breakage determination operation based on engine operation data, and performing a breakage protection operation after determining that the low-voltage rotor shaft is broken, the breakage determination operation including a third determination operation including: When the rotating speed of the high-pressure rotor is larger than the rotating speed of the slow vehicle and the rotating speed reduction rate of the low-pressure rotor exceeds the set speed, calculating to obtain a predicted value of inlet pressure based on fuel flow data supplied to the engine in a third set time of the rotating speed reduction of the low-pressure rotor; And calculating a judging threshold value based on the estimated value of the inlet pressure and the measured value of the inlet pressure, and judging that the low-pressure rotor shaft is broken when the judging threshold value is larger than a set threshold value. Further, calculating an estimated value of the inlet pressure based on the fuel flow data supplied to the engine includes: Calculating the fuel flow rate of change supplied to the engine within a fourth set time, and calculating an estimated value of the inlet pressure based on the fuel flow rate of change; the ratio of the difference between the predicted value of the inlet pressure and the measured value of the inlet pressure and the maximum value of the measured value of the inlet pressure in the third set time is taken as a judging threshold value. Further, the disconnection protecting operation includes a parking protection. Further, the shaft breakage determination job further includes a first determination job including: And when the rotating speed of the high-pressure rotor is larger than the rotating speed of the slow car and the rotating speed of the low-pressure rotor is smaller than the first set rotating speed and the first set time is continued, judging that the low-pressure rotor shaft is broken. Further, the first set