摘要 |
A dual circuit pilot burner fuel delivery arrangement (60) for a gas turbine engine combustor (18). A first fuel delivery circuit (64) delivers a gaseous fuel from a fuel supply (62) to a first diffusion outlet orifice (74). A second fuel delivery circuit (78) connects a second diffusion outlet orifice (82) to the first fuel delivery circuit through a pressure-regulated valve (86). Fuel is delivered to the second diffusion outlet orifice only when the fuel pressure in the first fuel delivery circuit is above a predetermined fuel pressure. At low fuel flow rates, the valve to the second fuel delivery circuit is closed, thereby generating a relatively high nozzle pressure drop across the first diffusion outlet orifice. This relatively high pressure drop makes the system less susceptible to acoustic instabilities that may otherwise result from feedback between the combustion dynamics and the fuel system.
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