A flow metering system includes a pump configured to urge a fluid flow from a fluid source, and a recirculation line located at the pump. A pressure regulating valve is located along the recirculating line. One or more fluid delivery lines extend downstream of the pump to deliver the fluid flow to one or more fluid consumers. A flow control valve is located along each fluid delivery line of the one or more fluid delivery lines. A system controller is operably connected to the pressure regulating valve and the one or more flow control valves. The system controller is configured to maintain a selected delta pressure and a selected flow rate of the fluid flow by operation of the pressure regulating valve and the one or more flow control valves.

A fuel control system for an aircraft engine, comprises a fuel feed conduit including an inlet end and an outlet end. A fuel metering mechanism is disposed in the fuel feed conduit between the inlet end and the outlet end operable to regulate flow through the fuel feed conduit. A position feedback sensor is operatively connected to the fuel metering mechanism and operable to generate a signal indicative of a position of the fuel metering mechanism.

Apparatus and associated methods relate to simultaneously pumping and measuring density of an aircraft fuel. The aircraft fuel is pumped by a centrifugal pump having an impeller. A rotational frequency of the impeller is determined while the centrifugal pump is pumping the aircraft fuel. Flow rate of the aircraft fuel through the centrifugal pump is sensed. Pressure of the aircraft fuel is measured at two different points within or across the centrifugal pump or a differential pressure is measured between the two different points while the centrifugal pump is pumping the aircraft fuel. Density of the aircraft fuel is determined based on a head-curve relation characterizing the centrifugal pump. The head-curve relation relates the fuel density to the rotational frequency, the flow rate, and pressures at the two different points or the differential pressure between the two different points.

An emissions control system for a gas turbine system includes a reducing agent supply, at least one sensor, at least one valve, and a controller. The reducing agent supply has one or more conduits configured to couple to one or more fluid pathways of the gas turbine system, which are fluidly coupled to a flow path of an exhaust gas from a combustor through a turbine of the gas turbine system. The at least one sensor is configured to obtain a feedback of one or more parameters of the gas turbine system, which are indicative of a visibility of emissions of the exhaust gas. The at least one valve is coupled to the reducing agent supply. The controller is communicatively coupled to the at least one sensor and the at least one valve, such that, in response to the feedback, the controller adjusts the at least one valve to adjust a flow of the reducing agent to reduce the visibility of the emissions of the exhaust gas.

A method of operating a fuel system for a vehicle having an engine, the fuel system comprising a fuel delivery system, the fuel delivery system including a liquid hydrogen delivery assembly and a regulator assembly, the regulator assembly having a buffer tank, the method including: providing a first flow of hydrogen fuel from a liquid hydrogen fuel tank through the liquid hydrogen delivery assembly to the regulator assembly, wherein providing the first flow of hydrogen fuel includes pumping the first flow of hydrogen fuel through the liquid hydrogen delivery assembly using a pump at a first fuel flowrate; receiving data indicative of a commanded fuel flowrate to the engine, wherein the commanded fuel flowrate is higher than the first fuel flowrate; and providing stored hydrogen fuel from a gaseous fuel storage to the engine.

A method and system for controlling fuel flow to an aircraft engine during start are provided. Following light-off, an actual value of at least one engine operating parameter is obtained. Based on a difference between the actual value and a target value, a first command is generated to cause fuel flow to be provided to the engine's combustor according to a computed fuel flow rate defined by a fuel schedule of the engine. When the computed fuel flow rate is within a fuel flow rate limit, the first command is output. Otherwise, a limiting factor is applied to the computed fuel flow rate to limit a reduction in fuel flow to the combustor and a limited fuel flow rate is obtained, and a second command is output to cause fuel flow to be provided to the combustor according to the limited fuel flow rate.

Devices, systems and methods for leak detection are provided herein. Also provided are devices, systems and methods for monitoring and/or measuring fluid usage. In some aspects, a system comprising a sensor, a processing system, and a platform are provided. In some aspects, the sensor may be coupled to a spinning device. The sensor can be configured to detect fluid data, which can comprise, for example, displacement data of liquid and/or movement data associated with the liquid in a container and/or flow data associated with a flow of fluid in a conduit. The processing system can be coupled with the sensor and configured to communicate the fluid data. The platform can comprise an application communicatively coupled to one or more databases storing evaluation data (e.g., known pattern data) and configured to receive the fluid data and determine if there is a leak.

The present disclosure relates to systems and methods that are useful in control of one or more aspects of a power production plant. More particularly, the disclosure relates to power production plants, methods of starting power production plants, and methods of generating power with a power production plant wherein one or more control paths are utilized for automated control of at least one action. The present disclosure more particularly relates to power production plants, control systems for power production plants, and methods for startup of a power production plant.

A method for controlling the fuel injection of a turbine engine using a fuel supply circuit. The supply circuit includes a pilot injection line and a main injection line. During a transition of the supply distribution between the pilot injection line and the main supply line, the method includes the following steps: a) determining at least a minimum value to be maintained for a pressure value; b) determining at least one hydraulic quantity of the supply circuit; c) based on the determined hydraulic quantity of the supply circuit, calculating a calculated fuel supply distribution value corresponding to the minimum value to be maintained; and switching the fuel supply distribution to the calculated fuel distribution value.

A method of controlling a gas turbine engine including receiving an instantaneous thrust demand for current operation of the engine, determining the inlet flow rate and/or the pressure ratio within the compressor of the engine and determining whether the inlet flow rate and/or the pressure ratio match the working line for the compressor. The angle of one or more vane of the compressor is adjusted according to a closed control loop if the inlet flow rate and/or pressure ratio lie outside said desired range in order to adjust the inlet inflow rate and/or pressure ratio to meet the working line. The fuel flow to the engine combustor is adjusted concurrently in order to meet the thrust demand.