Method of acceleration control during APU starting
AssigneeHamilton Sundstrand Corporation
InventorsWalter Ernest Ainslie, Andre M. Ajami, Mujtaba T. Saifuddin
Life of this patent
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Abstract
A method for controlling fuel flow to a gas turbine engine during starting includes monitoring acceleration of the gas turbine engine to determine actual acceleration value, and calculating a fuel flow rate for a setpoint acceleration using the actual acceleration value as a factor. The method further includes commanding the calculated fuel flow for the setpoint acceleration to the gas turbine engine.
Claims15
A method for controlling fuel flow to a gas turbine engine during starting, the method comprising:
- monitoring acceleration of the gas turbine engine unit to determine an actual acceleration value;
- populating an acceleration based fuel command look-up table with the actual acceleration of the gas turbine engine unit during starting;
- calculating a fuel flow rate for a setpoint acceleration using the actual acceleration value as a factor;
- and
- commanding the calculated fuel flow rate to the gas turbine engine.
A method for controlling fuel flow to an auxiliary power unit during starting, the method comprising:
- activating a starter for the auxiliary power unit;
- monitoring a speed of the auxiliary power unit;
- measuring an amount of time elapsed to reach a set speed to determine an actual acceleration of the auxiliary power unit;
- populating an acceleration look up table with the actual acceleration of the auxiliary power unit during starting;
- and
- controlling a rate of fuel flow to the auxiliary power unit during starting.
An auxiliary power unit comprising:
- a starter for starting rotation of an engine;
- a speed sensor for sensing engine speed;
- a fuel metering valve for metering fuel flow to the engine;
- and
- a controller connected to the starter, the speed sensor, and the fuel metering valve, the controller receiving the sensed engine speed and calculating acceleration of the engine, the controller commanding a fuel flow rate to the fuel metering valve, wherein the fuel flow rate is determined in part by the calculated acceleration of the engine;
- wherein the calculated acceleration of the engine is used as a multiplying factor in determining the fuel flow rate;
- and
- wherein the controller populates an acceleration based fuel command look up table with the calculated acceleration of the engine during starting of the engine.
Dependencies are inferred from the claim text.