Method of starting turbine engines

• US 4,350,008 A
• Filed: 12/26/1979
• Issued: 09/21/1982
• Est. Priority Date: 12/26/1979
• Status: Expired due to Term

• Current Assignee: United Technologies Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Original Assignee: United Technologies Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Zickwolf, Herbert C. Jr.
• Primary Examiner(s): Garrett, Robert E.
• Application Number:
  US06/107,461
• Time in Patent Office: 1,000 Days
• Field of Search: 60/39.14 R, 60/39.14 M, 60/39.28 R
• US Class Current: 60/39.281
• CPC Class Codes: F02C 7/26 Starting; Ignition

Abstract

A method of starting a gas turbine engine, particularly one having a high inertia rotor, in which the engine is cranked until sufficient air flow is available for lightoff, at which time fuel is injected at a fixed rate until ignition occurs, and fuel flow is then increased at a rate that is a function of rotor speed and ambient temperature. During the acceleration to operating speed, the turbine temperature is compared to a temperature reference that is based on rotor speed and ambient temperature and a lower fuel flow rate is selected, if necessary, to prevent overheating within the engine.

Claims

1. A method of starting a turbine engine including the steps of:

cranking the engine until sufficient air flow is available for lightoff;

admitting fuel at a fixed flow rate to the engine;

igniting the fuel; and

then

increasing the rotor speed to operating speed by increasing the fuel flow at a rate of change that is a function of both rotor speed and ambient temperature.

2. The method of claim 1 including the step of detecting ignition of the fuel by sensing the resulting temperature rise in the combustion chamber of the engine.

3. The method of claim 1 including the additional step of protecting the engine against turbine overtemperature by causing a fuel flow reduction if the sensed turbine exit temperature exceeds a reference temperature derived from ambient temperature and rotor speed.

4. The method of claim 3 in which the speed function and ambient temperature generate a signal and the turbine exit temperature generates another signal, the method including selecting the lower value signal for controlling the fuel flow.