Active clearance control method and system

Abstract

The invention relates to an active clearance control method and system. The method comprises the steps that the current state of an aero-engine is judged, and if the aero-engine is in a steady state, a closed-loop control process which is achieved by a closed-loop controller and based on clearance-related parameter adjustment and an actuator affecting turbine clearance is selected and used; if the aero-engine is in a transition state, an open-loop control process which is achieved by an open-loop controller and based on clearance-related parameter adjustment and the actuator is selected and used. According to the method, when the aero-engine is in the steady state, the closed-loop control process based on clearance-related parameters is adopted to ensure high control accuracy of the turbine clearance in the steady state; when the aero-engine is in the transition state, the open-loop control process based on the clearance-related parameters is adopted to make turbine clearance control respond more quickly in the transition state and avoid frequent actuation, caused by slow response, of the actuator affecting the turbine clearance; as a result, high control accuracy of the turbine clearance in the transition state is acquired, and the control effect of active clearance is improved.

Description

technical field [0001] The invention relates to the field of aero-engines, in particular to an active gap control method and system. Background technique [0002] High Pressure Turbine Active Clearance Control (HPTACC) technology is a technical measure to reduce engine fuel consumption and prolong service life by controlling the gap between engine high pressure turbine casing and blades. At the same time, the emission of pollutants also has a large contribution. [0003] Systems using HPTACC technology often adopt the principle of thermal control, that is, use the cooling air extracted from the compressor or fan to impinge on the high-pressure turbine casing and the outer ring support of the turbine, and change the high-pressure turbine by controlling the flow and temperature of the cooling air. The amount of thermal expansion of the casing, so that the gap between the rotor blade and the outer ring of the turbine reaches the expected value. [0004] Since HPTACC technolog...

AI Technical Summary

Problems solved by technology

Therefore, there is a scheme to control the turbine gap by indirectly controlling the temperature of the high-pressure turbine casing, but the disadvantage of this scheme is that it is difficult to obtain a control plan for the temperature of the turbine casing, and more importantly, the response of the temperature sensor of the turbine casing is very slow, which may easily lead to a transition state When the deflation valve moves frequently, the gap control accuracy becomes poor

This method is simple and the control response is fast, but the obvious disadvantage is that it is difficult to give the exact relationship between the target position of the bleed valve and the clearance of the high-pressure turbine in the full flight envelope, and the implementation is relatively conservative, and the steady-state clearance control Poor accuracy, when the performance of the engine is degraded, the gap control effect is even worse

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