Method and apparatus for monitoring turbine efficiency of aircraft auxiliary power unit

• Main Authors: Ma Hongtao, Zhang Yanfeng, Chen Lei, Zhang Chi, Gu Zhuping, Ding Huifeng, Huang Lei, Wu Jiaju
• Format: Patent
• Language: English
• Published: 04.07.2017
• Subjects: AIR INTAKES FOR JET-PROPULSION PLANTS; ARRANGEMENTS, SYSTEMS OR APPARATUS FOR CHECKING NOT PROVIDEDFOR ELSEWHERE; BLASTING; CHECKING-DEVICES; COMBUSTION ENGINES; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS; ENGINE PLANTS IN GENERAL; GAS-TURBINE PLANTS; GENERATING RANDOM NUMBERS; HEATING; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS; LIGHTING; MACHINES OR ENGINES IN GENERAL; MEASURING; MECHANICAL ENGINEERING; NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAMTURBINES; PHYSICS; REGISTERING OR INDICATING THE WORKING OF MACHINES; STEAM ENGINES; TESTING; TESTING STATIC OR DYNAMIC BALANCE OF MACHINES ORSTRUCTURES; TESTING STRUCTURES OR APPARATUS NOT OTHERWISE PROVIDED FOR; TIME OR ATTENDANCE REGISTERS; VOTING OR LOTTERY APPARATUS; WEAPONS

The present invention relates to a method and device for monitoring performance of an auxiliary power unit (APU) turbine efficiency of an aircraft. The method comprises: obtaining APU messages at multiple time points within a period; obtaining APU startup parameters including at least a rotation speed at a peak of EGT according to the APU messages; calculating a percentage NPA of the rotation speed when the exhausting gas temperature EGT reaches its peak at the APU startup stage relative to the rotation speed in the APU normal operation; calculating the average of the NPA within the period; and determining which of the stable, decline and failure phases the APU turbine efficiency is in according to the average of the NPA.