Patent ID: 8590317
Filing Date: 2013-11-26
Classification: F01D,F02C,F05D

Abstract:
1. A method of starting a gas turbine engine via a start sequence, comprising: coordinating turbine speed and fuel delivery to provide a fuel/air mixture at an ignition device of the gas turbine permitting a successful ignition; purging the gas turbine engine if a successful ignition has not occurred by the end of the start sequence; and repeating the start sequence after purging the gas turbine engine, when repeating the start sequence the fuel/air ratio of the fuel/air mixture is varied through a range of fuel/air ratios at which starting is most likely to occur in the start sequence, and in that the range of fuel/air ratios for the current start sequence is shifted and/or scaled in respect to the previous start sequence, wherein the shifting the range of the fuel/air ratios causes a start point of the fuel/air ratios of the current start sequence to be shifted in respect to a start point of the fuel/air ratio of the previous start sequence, and wherein the scaling of the range of the fuel/air ratios is a product of the range of the fuel/air ratios and a scale factor which results in the range of the fuel air ratios of the current start sequence to increase or decrease in respect to the range of the fuel/air ratios of the previous start sequence.