ELECTRICAL REGULATING SYSTEM FOR THE FUEL CIRCUIT OF A TURBINE MOTOR

摘要

An electrical control system for a fuel circuit including a low pressure pump, a high pressure pump, a throttle valve and a pressurizing valve connected in series between a fuel reservoir and the fuel injectors of a gas turbine engine includes a first device including a first solenoid controlled valve capable of interruption of the connection between the outlet of the throttle valve and an inlet to a pressure drop detector which is normally connected across the throttle valve. The output of the pressure drop detector controls a control valve which can by-pass high pressure fuel output from the high pressure pump back to the pump inlet. The first device includes two, identical, parallel control channels each provided with its own independent power supply, a control first switch with two positions each leading to a respective processing circuit which has its output connected to one terminal of a respective solenoid winding of the bistable first solenoid controlled valve. In the "start" position of the first switch each channel independently causes operation of its respective first solenoid controlled valve to make the fuel circuit between the output of the throttle valve and the input of the pressure drop detector allowing fuel to be supplied to the start-up injectors and then the main injectors of the jet engine. In the "stop" position the signal is processed to operate the bistable valves to "break" the fuel circuit between the output of the supply regulator and the input to the pressure detector. This causes the by-pass valve to by-pass the fuel from the outlet to the inlet of the high pressure pump, cutting off the fuel supply to the injectors and stopping the engine. A second device acts directly in the by-pass valve to supply the fuel reservoir pressure instead of the outlet from the pressure drop detector to the control input of the by-pass valve so as to cause the by-pass valve to open so that fuel is recirculated from the high pressure pump to its input. This second device acts as a safety cut-off device in the event of failure of the first device.