Methods and systems for starting an aircraft gas turbine engine are described. The method comprises, in a first phase of a startup upon receipt of a start request, modifying a first set of engine control parameters to cause light-up; in a second phase of the startup, modifying a second set of engine control parameters to set conditions for light-around; and in a third phase of the startup, modifying a third set of engine control parameters to propagate a flame around a combustor of the gas turbine engine.

A combustion-gas supply system and a combustion-gas supply method thereof, a device equipped with a turbine engine, and a fracturing system are provided. The combustion-gas supply system includes a main pipeline and a multi-functional pipeline; the main pipeline includes a first sub-pipeline and a second sub-pipeline; the first sub-pipeline includes a first gas intake pipe, a first gas supply valve and a first gas outlet pipe arranged in sequence; the second sub-pipeline includes a combustion-gas supply valve and a gas supply pipe, the first gas outlet pipe is connected with the combustion-gas supply valve, the gas supply pipe is configured to be connected with a turbine engine, the multi-functional pipeline includes a second gas intake pipe, a second gas supply valve and a second gas outlet pipe arranged in sequence, and the second gas outlet pipe is communicated with the first gas outlet pipe.

A passive flow splitting system for use in a turbine engine control system to provide split fuel flow to two fuel manifolds to supply primary and secondary fuel injectors for the particular combustion zones thereof utilizing intentionally different split ratios dependent on ascending or descending combustion fuel flow is provided. The system includes a passive fuel divider valve (FDV) that includes a primary piston and a secondary piston. The primary piston is moveable independently from the secondary piston during a portion of its stroke, and is hydro-locked to the secondary piston during another portion of its stroke. An ecology valve is also provided to purge the fuel from the primary and/or secondary manifolds during different modes of operation. A transfer valve is included to control the position of ecology piston of the ecology valve.

A piezoelectric ring bender servo valve assembly reduces mechanical wear by removing mechanical components used in prior art servo valves. The assembly does not use torque motor, flapper, and feedback spring. In this manner, no moving parts are required, which reduces maintenance and costs. A pair of piezoelectric ring benders mount adjacently to a pair of nozzles. The piezoelectric ring benders independently regulate the flow of fluid through the nozzles by moving between an open position to enable flowage, and a closed position to restrict flowage. A linear position sensing device measures and provides feedback about the spool position to a valve controller. The valve controller allows the spool valve to move until valve position achieves command position and the force on the spool valve is in equilibrium with pressure difference across spool valve. An H-bridge operable to switch the polarity of a differential pressure applied across to a load.

A piezoelectric ring bender servo valve assembly reduces mechanical wear by removing mechanical components used in prior art servo valves. The assembly does not use torque motor, flapper, and feedback spring. In this manner, no moving parts are required, which reduces maintenance and costs. A pair of piezoelectric ring benders mount adjacently to a pair of nozzles. The piezoelectric ring benders independently regulate the flow of fluid through the nozzles by moving between an open position to enable flowage, and a closed position to restrict flowage. A linear position sensing device measures and provides feedback about the spool position to a valve controller. The valve controller allows the spool valve to move until valve position achieves command position and the force on the spool valve is in equilibrium with pressure difference across spool valve. An H-bridge operable to switch the polarity of a differential pressure applied across to a load.

A control system for a gas turbine includes a controller. The controller includes a processor configured to receive a plurality of signals comprising a temperature signal, a pressure signal, a speed signal, a mass flow signal, or a combination thereof, from sensors disposed in the gas turbine system. The processor is further configured to apply the plurality of signals as input to a heating value model. The processor is also configured to execute the heating value model to derive a heating value for a fuel combusted by the gas turbine system. The processor is additionally configured to control operations of the gas turbine system based on the heating value for the fuel.

Various examples of an active combustion control valve, combustion systems, and method of controlling the flow of liquid fluid in a gas combustion system are described. In one aspect of the present invention, an active combustion control valve includes a core valve housing, an actuator, a valve seat in communication with the actuator, and a passageway in fluid communication with the core valve housing and the valve seat. The control valve is responsive to change in voltage applied to the actuator and is capable of a first condition permitting a first fluid flow through the passageway and a second condition permitting a second fluid flow through the passageway, the first fluid flow being different than the second fluid flow. The combustion control valve is small, robust, responsive and self-cooling to operate in severe thermal environment.

Various examples of an active combustion control valve, combustion systems, and method of controlling the flow of liquid fluid in a gas combustion system are described. In one aspect of the present invention, an active combustion control valve includes a core valve housing, an actuator, a valve seat in communication with the actuator, and a passageway in fluid communication with the core valve housing and the valve seat. The control valve is responsive to change in voltage applied to the actuator and is capable of a first condition permitting a first fluid flow through the passageway and a second condition permitting a second fluid flow through the passageway, the first fluid flow being different than the second fluid flow. The combustion control valve is small, robust, responsive and self-cooling to operate in severe thermal environment.

A gas turbine engine shut-down system includes a pump configured to draw a flow of fuel from a source, a fuel nozzle configured to receive the flow of fuel from the pump, a fuel shut-off valve in fluid communication with the pump, a recirculation circuit for circulating excess fuel to a location upstream of the pump; a solenoid valve in communication with the pump and the recirculation circuit; and a fuel-bypass valve. The fuel-bypass valve includes a first opening connected to the fuel pump, a second opening connected to the fuel shut-off valve, a third opening connected to the recirculation circuit, a fourth opening connected to the solenoid valve, and a piston disposed within the fuel-bypass valve and movable between a plurality of positions.

In an embodiment, a system includes a gas turbine controller. The gas turbine controller is configured to receive a plurality of sensor signals from a fuel composition sensor, a pressure sensor, a temperature sensor, a flow sensor, or a combination thereof, included in a gas turbine engine system. The controller is further configured to execute a gas turbine model by applying the plurality of sensor signals as input to derive a plurality of estimated gas turbine engine parameters. The controller is also configured to execute a flame holding model by applying the plurality of sensor signals and the plurality of estimated gas turbine engine parameters as input to derive a steam flow to fuel flow ratio that minimizes or eliminates flame holding in a fuel nozzle of the gas turbine engine system.