Protection method and system for preventing overrunning fracturing of turbine of aviation turboshaft engine

Abstract

The invention discloses a protection method and system for preventing overrunning fracturing of a turbine of an aviation turboshaft engine. The protection method for preventing overrunning fracturing of the turbine of the aviation turboshaft engine comprises the steps that a parameter change trend generated when a power turbine shaft of the engine is fractured or related connection fails is analyzed; significant test data characteristics are determined according to the parameter change trend; a fault condition is determined according to the significant test data characteristics; whether the fault condition reaches a threshold value or not is detected; and when the fault condition reaches the set threshold value, protection measures are taken, and fault information is indicated. According to the method and system, the significant test data characteristics are obtained by analyzing the parameter change trend generated when the power turbine shaft fractures or related connection fails, the high-rotating-speed and low-torque protection method is provided, the rotating speed and the torque or the torque decline slope of a fuel gas generator serve as judgment conditions, when the fault condition is met at the same time, emergency automatic stop protection is carried out on the engine, destructive overrunning of a power turbine is prevented, the response is rapid, and the test safety is improved.

Description

technical field [0001] The invention belongs to the technical field of aero-engine control, and in particular relates to a protection method and system for preventing over-rotation rupture of an aero turboshaft engine turbine. Background technique [0002] For the aero turboshaft engine whose turbine components adopt the bearing common cavity structure, there is no speed measuring mechanism behind the power turbine. If the power turbine shaft breaks or the related connection fails, the power turbine speed will rise sharply, but its actual speed cannot be detected. As the power turbine speed displayed by the engine control system drops, the control system will continue to increase the fuel supply at this time, and the engine status does not drop but rises, resulting in a sharp increase in the power turbine speed, and there is a risk that the turbine will over-rotate and rupture and seriously damage the engine. [0003] At present, the protection methods for the ground test sp...

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Problems solved by technology

[0002] For the aero turboshaft engine whose turbine components adopt the bearing common cavity structure, there is no speed measuring mechanism behind the power turbine. If the power turbine shaft breaks or the related connection fails, the power turbine speed will rise sharply, but its actual speed cannot be detected

As the speed of the power turbine displayed by the engine control system decreases, the control system will continue to increase the fuel supply at this time, and the engine status will rise instead of falling, resulting in a sharp increase in the speed of the power turbine.

[0003] At present, the protection methods for the ground test speed, temperature and torque of aviation turboshaft engines are all high-value setting protection methods, and there is no emergency automatic protection method for the actual power turbine speed that cannot be detected when the power turbine shaft breaks or related connections fail. , by human judgment and response or at the engine gas generator speed n g 1. When the gas temperature reaches the protection setting value, the protection stop will be triggered. There is a risk of low efficiency and large damage. Even if the processing time is delayed by a few seconds, the damage to the engine will be great, and there will be over-rotation of the engine wheel disc. risks of

At present, in the prior art, the speed n of the gas generator is not set at the same time g Rise and rapid torque drop or torque drop slope are used as the fault conditions for judging the over-rotation of aviation turboshaft engines, so there is an urgent need for a protection method to prevent over-rotation of aviation turboshaft engine turbines

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