Patent ID: 9689311
Date: 2017-06-27
CPC Classifications: B64D,F01M,F02C,F05D,G01M,Y02T

Claim:
1. A method for monitoring performance of an aircraft auxiliary power unit APU lubricant cooler, comprising: acquiring APU messages within a time period; obtaining the operation parameters of the APU lubricant cooler according to the APU messages, the operation parameters including lubricant temperature OTA and load compressor inlet temperature LCIT; obtaining a revised lubricant temperature OT by: determining whether the performance of the APU lubricant cooler is in stable phase, decline phase or malfunction phase according to change trend of the revised lubricant temperature OT with respect to time, the determining comprising: wherein, the threshold value of the decline phase is around 1.5-2.5 times than the stable change trend, and the threshold value of malfunction is around 5-7 times than the stable change trend.