摘要:
A turbine engine (49) fuel delivery system of the type including a pneumatic governor has an electronic governor and an engine excess stress avoidance feature which disable the pneumatic governor (70) so long as the engine speed exceeds a prescribed value and an electronic control unit (45) continues to function properly. The system transfers governing responsibility to the electronic control unit (45) which controls a torque motor and solenoid valve fuel diversion line (22). The system monitors an engine (49) operating parameter such as gas generator speed (37), power turbine speed, engine output torque, or engine temperature and further diminishes fuel flow to the engine (49) when the monitored parameter exceeds a threshold value. The system resumes normal speed governoring flow when that parameter returns to an acceptable level The system also senses rotor blade pitch to reduce rotor droop and increases fuel flow to the engine (49) when the pitch (44) increases, and decreasing the fuel flow to the engine (49) when the rotor blade pitch (44) decreases.
摘要:
A turbine engine (49) fuel delivery system of the type including a pneumatic governor has an electronic governor and an engine excess stress avoidance feature which disable the pneumatic governor (70) so long as the engine speed exceeds a prescribed value and an electronic control unit (45) continues to function properly. The system transfers governing responsibility to the electronic control unit (45) which controls a torque motor and solenoid valve fuel diversion line (22). The system monitors an engine (49) operating parameter such as gas generator speed (37), power turbine speed, engine output torque, or engine temperature and further diminishes fuel flow to the engine (49) when the monitored parameter exceeds a threshold value. The system resumes normal speed governoring flow when that parameter returns to an acceptable level. The system also senses rotor blade pitch to reduce rotor droop and increases fuel flow to the engine (49) when the pitch (44) increases, and decreasing the fuel flow to the engine (49) when the rotor blade pitch (44) decreases.
摘要:
A turbine engine fuel delivery system (10) and method has, in addition to the conventional fuel bypass (20) for diverting fuel exiting a fuel control (17) away from the engine (49) and back to a fuel pump (15) to maintain a relatively constant pressure differential across the fuel control (17), a separate controllable flow fuel bypass (21) for selectively diverting fuel exiting the fuel control (17) away from the engine (49) and back to the fuel pump (15) to decrease the rate of fuel flow to the engine (49) and correct an overtemperature condition, and an arrangement for enabling the controllable fuel flow bypass (21) during engine (49) start-up and disabling the controllable fuel flow bypass (21) when the engine (49) reaches normal idle speed. Once an engine (49) start or light off is detected, the system (10) automatically prevents turbine outlet temperature exceedences by reducing metered fuel flow to the engine nozzle. The controllable fuel bypass (21) includes a solenoid operable valve (29). A controller (45) is responsive to sensed exhaust gas temperature and supplies a pulse width modulated control signal to the solenoid operable valve (29) which cyclically enables and disables the return flow of a portion of the fuel flow to the engine (49) from the main fuel control (17) back to the engine fuel pump (15). The period of cyclic enabling and disabling is fixed and the fraction of each cycle during which enabling occurs is controlled in accordance with the monitored exhaust gas temperature. The fuel bypass (21) includes a particulate matter filter (25, 31), a flow limiting orifice (27), and the solenoid actuatable valve (29), and a check valve (23) connected in series between the fuel control (17) and the fuel pump (15).