Method and apparatus for monitoring efficiency of aircraft auxiliary power unit

• Main Authors: HUANG, LEI, CHEN, LEI, WU, JIAJU, GU, ZHUPING, MA, HONGTAO, DING, HUIFENG, ZHANG, YANFENG, ZHANG, CHI
• Format: Patent
• Language: English
• Published: 12.02.2015
• Subjects: AIR INTAKES FOR JET-PROPULSION PLANTS; AIRCRAFT; ARRANGEMENTS OR MOUNTING OF POWER PLANTS OR PROPULSIONTRANSMISSIONS IN AIRCRAFT; AVIATION; BLASTING; COMBUSTION ENGINES; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS; COSMONAUTICS; EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLYING SUITS; GAS-TURBINE PLANTS; HEATING; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS; LIGHTING; MECHANICAL ENGINEERING; PARACHUTES; PERFORMING OPERATIONS; TRANSPORTING; WEAPONS

Abstract 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 5 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 o 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. 300 200 100 2100 120 130 310 -- Figure 1