A gas turbine engine and method of operation are provided. The gas turbine engine may include a variable geometry component operably driven by a component actuator. The component actuator may be in fluid communication with a primary line having a valve associated therewith. The method may include determining a demand pressure associated with actuating the variable geometry component using the component actuator. The method may also include adjusting a position of the valve based on the demand pressure to generate a fuel pressure at the component actuator that is greater than or equal to the demand pressure.

A fuel system can include a total flow line configured to receive a total flow and a primary flow line connected to the total flow line. The primary flow line can be in fluid communication with one or more primary fuel nozzles of a nozzle assembly. The fuel system can include a secondary flow line connected to the total flow line in parallel with the primary flow line, the secondary flow line in fluid communication with a plurality of secondary flow nozzles of the nozzle assembly. The fuel system can include a flow split system configured to control a flow split between a primary flow of the primary flow line and a secondary flow of the secondary flow line.

A system includes a flow inlet conduit. A primary conduit branches from the flow inlet conduit for delivering flow to a set of primary nozzles. An equalization bypass valve (EBV) connects between the flow inlet conduit and a secondary conduit for delivering flow to a set of secondary nozzles. The EBV is connected to be controlled to apportion flow from the flow inlet conduit to the secondary conduit. A secondary equalization valve (SEV) connects between the flow inlet conduit and the secondary conduit. The SEV is connected to be controlled by drain pressure (PD) to apportion flow from the flow inlet conduit to the secondary conduit.

A fuel conditioning and control system provides dynamic control and steady state operations of a gas turbine provided fueled by supercritical liquefied petroleum gas (LPG). The fuel conditioning and control system comprises a storage for LPG fuel; a fuel delivery sub-system connecting the storage to turbomachinery; and a control system. The gas turbine includes a gas turbine core control that provides at least one operational data of the gas turbine to the control system. The fuel delivery sub-system includes at least one sensor for sensing at least one property of the LPG fuel in the fuel delivery sub-system, where the at least one sensor providing data on the at least one property of the LPG fuel to the control system. The control system analyzes the data on the at least one property of the LPG fuel and at least one operational data of the gas turbine for dynamic control of LPG fuel to the gas turbine under dynamic and steady state conditions.

The method allows to control a test apparatus for a gas turbine engine; WI values of one or more tentative fuel gas mixtures are predicted by calculations and the predicted WI values are used for setting the composition of a fuel gas mixture to be supplied to a combustor of a gas turbine engine under test. The test apparatus comprises: a first supply flow line for fuel gas; a second supply flow line for inert gas; a mixer with a first inlet for fuel gas and a second inlet for inert gas, and with an outlet for supplying the mixture of fuel gas and inert gas to the combustor; a set of meters; and a flow control device for the inert gas.

A fuel control system for a gas turbine engine includes a fuel metering valve, a pressure raising and shut-off valve (PRSOV), and a shutoff effector including a first stage unit that is electrically powered and a second stage unit that is controlled by the first stage unit. The second stage unit actuates a valve member of the PRSOV between an open position that allows supply of a fuel to burners of the gas turbine engine and a closed position that prevents supply of the fuel to the burners. Upon loss of electrical power to the first stage unit during operation of the gas turbine engine, the first stage unit is configured to: control the second stage unit to actuate the valve member of the PRSOV to the closed position after a predetermined time duration; or retain the valve member of the PRSOV in the open position.

A fuel pump system can include a motor and a pump connected to the motor. The pump can be configured to receive an inlet flow from an inlet line, to pressurize the inlet flow, and to output a pressurized flow to an output line for an engine. The system can include a bypass line disposed between the outlet line and the inlet line, and a bypass valve disposed on the bypass line and configured to allow pressurized flow to flow to the inlet line in an open state, and to prevent pressurized flow from flowing to the inlet line in a closed state. The bypass valve can be configured to allow pressurized flow to flow to the inlet line to circulate flow and to maintain a constant pressure on the output line.

A fluid delivery system can include a main pump disposed in a primary fluid line configured to receive a low pressure fluid on a low pressure side and output a high pressure fluid on a high pressure side to provide flow from the fluid source to a fluid destination via the primary fluid line. An interconnected valve system can be disposed in the primary fluid line configured to control flow through the primary fluid line.

A system for monitoring fuel additives on board a vehicle includes a fuel line carrying fuel from a fuel source to an engine; a fuel additive sensor configured to measure concentration of additives in fuel at a point along the fuel line; a fuel additive dispenser connected in parallel to the fuel line; at least one flow control device for controlling an amount of flow from the fuel line into the fuel additive dispenser; and a controller configured to receive input from the fuel additive sensor and to control the flow control device to adjust the amount of the flow from the fuel line into the fuel additive dispenser.

A speed control system and a power load balance detector for a turbine is provided. The speed control system includes a speed wheel with a plurality of teeth. A timer stores a time stamp when each of the teeth passes by a speed probe. A first speed estimate is determined for overspeed protection, and a second speed estimate is determined for operational speed control. The power load balance detector trips or shuts down the turbine when an unbalance is above a first threshold and the speed of the turbine is above a second threshold.