Patent ID: 9086018
Filing Date: 2015-07-21
Classification: F02C,F02K,F05B

Abstract:
1. A method of starting an auxiliary power unit comprising the steps of: (a) controlling a speed of a starter motor during a start sequence to drive the auxiliary power unit at a dwelling speed, the dwelling speed lower than an operating speed; (b) actuating an igniter in the start sequence to achieve light-off in a combustor of the auxiliary power unit; (c) maintaining the auxiliary power unit at the dwelling speed after light-off in the start sequence until an instant exhaust gas temperature (EGT) exceeds an initial EGT by greater than a predetermined magnitude with respect to avoiding flame-out upon acceleration of the auxiliary power unit from step (d); and (d) increasing the speed of the starter motor to accelerate the auxiliary power unit in the start sequence in response to achieving the predetermined magnitude, wherein the start sequence is initiated only in response to predetermined engine start conditions and another, different start sequence is initiated in response to being outside of the predetermined engine start conditions.